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Sample records for amsr aqua amsr-e

  1. GHRSST Level 2P Global Subskin Sea Surface Temperature from the Advanced Scanning Microwave Radiometer - Earth Observing System (AMSR-E) on the NASA Aqua Satellite (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Advanced Microwave Scanning Radiometer (AMSR-E) was launched on 4 May 2002, aboard NASA's Aqua spacecraft. The National Space Development Agency of Japan...

  2. GHRSST Level 2P Gridded Global Subskin Sea Surface Temperature from the Advanced Scanning Microwave Radiometer - Earth Observing System (AMSR-E) on the NASA Aqua Satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Advanced Microwave Scanning Radiometer (AMSR-E) was launched on 4 May 2002, aboard NASA's Aqua spacecraft. The National Space Development Agency of Japan...

  3. GHRSST Level 2P Regional Subskin Sea Surface Temperature from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) on the NASA Aqua satellite for the Atlantic Ocean (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Advanced Microwave Scanning Radiometer (AMSR-E) was launched on 4 May 2002, aboard NASA's Aqua spacecraft. The National Space Development Agency of Japan...

  4. AMSR-E/Aqua Daily L3 12.5 km Tb, Sea Ice Conc., & Snow Depth Polar Grids V002

    Data.gov (United States)

    National Aeronautics and Space Administration — The AMSR-E/Aqua Level 3 12.5 km daily sea ice product includes 18.7 - 89.0 GHz TBs, sea ice concentration averages (asc & desc), and 5-day snow depth over sea...

  5. Cloud-type dependencies of MODIS and AMSR-E liquid water path differences

    OpenAIRE

    Torre Juárez, M.; B. H. Kahn; E. J. Fetzer

    2009-01-01

    Comparisons of cloud liquid water path (LWP) retrievals are presented from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Microwave Scanning Radiometer (AMSR-E) located aboard the Aqua spacecraft. LWP differences as a function of cloud top height, cloud fraction, cloud top temperature, LWP, cloud effective radius and cloud optical thickness are quantified in most geophysical conditions. The assumption of vertica...

  6. Retrieved sea surface temperature analysis of MODIS and AMSR-E aboard AQUA satellite for the northern Indian Ocean%AQUA卫星的MODIS和AMSR-E反演的印度洋北部海域海表温度特征对比分析

    Institute of Scientific and Technical Information of China (English)

    霍文娟; 韩震

    2013-01-01

    In this paper, the northern Indian Ocean served as the study area. Characteristics of sea surface temperature retrieved from MODIS and AMSR-E sensor aboard AQUA satellite were analyzed from three aspects, namely, the location,the temperature curve and the inversion accuracy. The main characteristics showed that the difference of MODIS SST and the AMSR-E SST changed with the latitude obviously; AMSR-E SST failed to offer accurate sea surface temperature in the coastal region; the diversity of MODIS SST and AMSR-E SST changed with the temperature differences. In this paper, the retrieval accuracy of AMSR-E SST was often better than that of MODIS SST. The result of this study had important reference to the sea surface temperature quantitative inversion using the thermal infrared and passive microwave remote sensing technology.%以印度洋北部海域为研究区域,分别从地理位置、温度曲线和反演精度3个方面对AQUA卫星上的MODIS和AMSR-E反演的海表温度特征进行了对比分析。其主要特征表现为MODIS SST与AMSR-E SST之间的差异随纬度变化较为明显;在近岸区域,AMSR-E SST无法获得准确的海表面温度;MODIS SST与AMSR-E SST之间的差异随温度而不同;在本次研究中,AMSR-E SST反演精度总体优于MODIS SST。本次研究结果对利用热红外遥感和被动微波遥感进行海洋表面温度的定量反演具有重要的参考价值。

  7. Detection and correction of AMSR-E radio-frequency interference

    Science.gov (United States)

    Wu, Ying; Weng, Fuzhong

    2011-10-01

    Radio-frequency interference (RFI) affects greatly the quality of the data and retrieval products from space-borne microwave radiometry. Analysis of the Advanced Microwave Scanning Radiometer on the Earth Observing System (AMSR-E) Aqua satellite observations reveals very strong and widespread RFI contaminations on the C- and X-band data. Fortunately, the strong and moderate RFI signals can be easily identified using an index on observed brightness temperature spectrum. It is the weak RFI that is difficult to be separated from the nature surface emission. In this study, a new algorithm is proposed for RFI detection and correction. The simulated brightness temperature is used as a background signal ( B) and a departure of the observation from the background ( O-B) is utilized for detection of RFI. It is found that the O-B departure can result from either a natural event (e.g., precipitation or flooding) or an RFI signal. A separation between the nature event and RFI is further realized based on the scattering index (SI). A positive SI index and low brightness temperatures at high frequencies indicate precipitation. In the RFI correction, a relationship between AMSR-E measurements at 10.65 GHz and those at 18.7 or 6.925 GHz is first developed using the AMSR-E training data sets under RFI-free conditions. Contamination of AMSR-E measurements at 10.65 GHz is then predicted from the RFI-free measurements at 18.7 or 6.925 GHz using this relationship. It is shown that AMSR-E measurements with the RFI-correction algorithm have better agreement with simulations in a variety of surface conditions.

  8. The construction and application of the AMSR-E global microwave emissivity database

    Science.gov (United States)

    Lijuan, Shi; Yubao, Qiu; Jingjing, Niu; Wenbo, Wu

    2014-03-01

    Land surface microwave emissivity is an important parameter to describe the characteristics of terrestrial microwave radiation, and is the necessary input amount for inversion various geophysical parameters. We use brightness temperature of the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and synchronous land surface temperature and atmospheric temperature-humidity profile data obtained from the MODIS which aboard on satellite AQUA the same as AMSR-E, to retrieved microwave emissivity under clear sky conditions. After quality control, evaluation and design, the global microwave emissivity database of AMSR-E under clear sky conditions is established. This database include 2002-2011 years, different regions, different surface coverage, dual-polarized, 6.9,10.65, 18.7, 23.8, 36.5 and 89GHz, ascending and descending orbit, spatial resolution 25km, global 0.05 degrees, instantaneous and half-month averaged emissivity data. The database can provide the underlying surface information for precipitation algorithm, water-vapor algorithm, and long-resolution mode model (General Circulation Model (GCM) etc.). It also provides underlying surface information for the satellite simulator, and provides basic prior knowledge of land surface radiation for future satellite sensors design. The emissivity database or the fast emissivity obtained can get ready for climate model, energy balance, data assimilation, geophysical model simulation, inversion and estimates of the physical parameters under the cloud cover conditions.

  9. The construction and application of the AMSR-E global microwave emissivity database

    International Nuclear Information System (INIS)

    Land surface microwave emissivity is an important parameter to describe the characteristics of terrestrial microwave radiation, and is the necessary input amount for inversion various geophysical parameters. We use brightness temperature of the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and synchronous land surface temperature and atmospheric temperature-humidity profile data obtained from the MODIS which aboard on satellite AQUA the same as AMSR-E, to retrieved microwave emissivity under clear sky conditions. After quality control, evaluation and design, the global microwave emissivity database of AMSR-E under clear sky conditions is established. This database include 2002–2011 years, different regions, different surface coverage, dual-polarized, 6.9,10.65, 18.7, 23.8, 36.5 and 89GHz, ascending and descending orbit, spatial resolution 25km, global 0.05 degrees, instantaneous and half-month averaged emissivity data. The database can provide the underlying surface information for precipitation algorithm, water-vapor algorithm, and long-resolution mode model (General Circulation Model (GCM) etc.). It also provides underlying surface information for the satellite simulator, and provides basic prior knowledge of land surface radiation for future satellite sensors design. The emissivity database or the fast emissivity obtained can get ready for climate model, energy balance, data assimilation, geophysical model simulation, inversion and estimates of the physical parameters under the cloud cover conditions

  10. An Updated Geophysical Model for AMSR-E and SSMIS Brightness Temperature Simulations over Oceans

    Directory of Open Access Journals (Sweden)

    Elizaveta Zabolotskikh

    2014-03-01

    Full Text Available In this study, we considered the geophysical model for microwave brightness temperature (BT simulation for the Atmosphere-Ocean System under non-precipitating conditions. The model is presented as a combination of atmospheric absorption and ocean emission models. We validated this model for two satellite instruments—for Advanced Microwave Sounding Radiometer-Earth Observing System (AMSR-E onboard Aqua satellite and for Special Sensor Microwave Imager/Sounder (SSMIS onboard F16 satellite of Defense Meteorological Satellite Program (DMSP series. We compared simulated BT values with satellite BT measurements for different combinations of various water vapor and oxygen absorption models and wind induced ocean emission models. A dataset of clear sky atmospheric and oceanic parameters, collocated in time and space with satellite measurements, was used for the comparison. We found the best model combination, providing the least root mean square error between calculations and measurements. A single combination of models ensured the best results for all considered radiometric channels. We also obtained the adjustments to simulated BT values, as averaged differences between the model simulations and satellite measurements. These adjustments can be used in any research based on modeling data for removing model/calibration inconsistencies. We demonstrated the application of the model by means of the development of the new algorithm for sea surface wind speed retrieval from AMSR-E data.

  11. Long-Term Evaluation of the AMSR-E Soil Moisture Product Over the Walnut Gulch Watershed, AZ

    Science.gov (United States)

    Bolten, J. D.; Jackson, T. J.; Lakshmi, V.; Cosh, M. H.; Drusch, M.

    2005-12-01

    The Advanced Microwave Scanning Radiometer -Earth Observing System (AMSR-E) was launched aboard NASA's Aqua satellite on May 4th, 2002. Quantitative estimates of soil moisture using the AMSR-E provided data have required routine radiometric data calibration and validation using comparisons of satellite observations, extended targets and field campaigns. The currently applied NASA EOS Aqua ASMR-E soil moisture algorithm is based on a change detection approach using polarization ratios (PR) of the calibrated AMSR-E channel brightness temperatures. To date, the accuracy of the soil moisture algorithm has been investigated on short time scales during field campaigns such as the Soil Moisture Experiments in 2004 (SMEX04). Results have indicated self-consistency and calibration stability of the observed brightness temperatures; however the performance of the moisture retrieval algorithm has been poor. The primary objective of this study is to evaluate the quality of the current version of the AMSR-E soil moisture product for a three year period over the Walnut Gulch Experimental Watershed (150 km2) near Tombstone, AZ; the northern study area of SMEX04. This watershed is equipped with hourly and daily recording of precipitation, soil moisture and temperature via a network of raingages and a USDA-NRCS Soil Climate Analysis Network (SCAN) site. Surface wetting and drying are easily distinguished in this area due to the moderately-vegetated terrain and seasonally intense precipitation events. Validation of AMSR-E derived soil moisture is performed from June 2002 to June 2005 using watershed averages of precipitation, and soil moisture and temperature data from the SCAN site supported by a surface soil moisture network. Long-term assessment of soil moisture algorithm performance is investigated by comparing temporal variations of moisture estimates with seasonal changes and precipitation events. Further comparisons are made with a standard soil dataset from the European

  12. Research on Monitoring of Soil Humidity Based on AMSR-E Data

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to establish AMSR-E soil humidity monitoring model to realize the real-time monitoring of soil humidity.[Method] By dint of evaporation(small type) in Guangxi,daily precipitation,daily average maximum temperature,daily minimum relative humidity,≤ 5 mm precipitation day,as well as AMSR-E soil humidity data,with Stepwise regression method,soil humidity real-time monitoring was studied based on GIS technology,and monitoring result.[Result] The low soil humidity in Guangxi on September 2...

  13. Statistical Analysis of the Correlation between Microwave Emission Anomalies and Seismic Activity Based on AMSR-E Satellite Data

    Science.gov (United States)

    qin, kai; Wu, Lixin; De Santis, Angelo; Zhang, Bin

    2016-04-01

    Pre-seismic thermal IR anomalies and ionosphere disturbances have been widely reported by using the Earth observation system (EOS). To investigate the possible physical mechanisms, a series of detecting experiments on rock loaded to fracturing were conducted. Some experiments studies have demonstrated that microwave radiation energy will increase under the loaded rock in specific frequency and the feature of radiation property can reflect the deformation process of rock fracture. This experimental result indicates the possibility that microwaves are emitted before earthquakes. Such microwaves signals are recently found to be detectable before some earthquake cases from the brightness temperature data obtained by the microwave-radiometer Advanced Microwave-Scanning Radiometer for the EOS (AMSR-E) aboard the satellite Aqua. This suggested that AMSR-E with vertical- and horizontal-polarization capability for six frequency bands (6.925, 10.65, 18.7, 23.8, 36.5, and 89.0 GHz) would be feasible to detect an earthquake which is associated with rock crash or plate slip. However, the statistical analysis of the correlation between satellite-observed microwave emission anomalies and seismic activity are firstly required. Here, we focus on the Kamchatka peninsula to carry out a statistical study, considering its high seismicity activity and the dense orbits covering of AMSR-E in high latitudes. 8-years (2003-2010) AMSR-E microwave brightness temperature data were used to reveal the spatio-temporal association between microwave emission anomalies and 17 earthquake events (M>5). Firstly, obvious spatial difference of microwave brightness temperatures between the seismic zone at the eastern side and the non-seismic zone the western side within the Kamchatka peninsula are found. Secondly, using both vertical- and horizontal-polarization to extract the temporal association, it is found that abnormal changes of microwave brightness temperatures appear generally 2 months before the

  14. Flood and Waterlogging Monitoring over Huaihe River Basin by AMSR-E Data Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHENG Wei; LIU Chuang; XIN Zhongbao; WANG Zhengxing

    2008-01-01

    In this paper,we investigated the potential of Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) for flood monitoring.The proposed approach was based on the polarized ratio index (PRI),which was computed by using AMSR-E data at 37GHz,vertically and horizontally polarized brightness temperature values and the water surface fraction (WSF) got by using the PRI at 37GHz.Moderate Resolution Imaging Spectroradiometer (MODIS) data were used to validate the WSF values.The analysis of flood and waterlogging using the WSF map on July 6,2003 indicates that the use of WSF for flood and waterlogging disaster assessment is feasible.Utilizing the correlation of WSF derived from AMSR-E and water area derived from MODIS,the water area of the Huaihe River Basin were computed by only using AMSR-E data in the summer of 2003,which overcame the influence of cloud on water estimation using MODIS data during flood.

  15. Subsurface Emission Effects in AMSR-E Measurements: Implications for Land Surface Microwave Emissivity Retrieval

    Science.gov (United States)

    Galantowicz, John F.; Moncet, Jean-Luc; Liang, Pan; Lipton, Alan E.; Uymin, Gennady; Prigent, Catherine; Grassotti, Christopher

    2011-01-01

    An analysis of land surface microwave emission time series shows that the characteristic diurnal signature associated with subsurface emission in sandy deserts carry over to arid and semi-arid region worldwide. Prior work found that diurnal variation of Special Sensor Microwave/Imager (SSM/I) brightness temperatures in deserts was small relative to International Satellite Cloud Climatology Project land surface temperature (LST) variation and that the difference varied with surface type and was largest in sand sea regions. Here we find more widespread subsurface emission effects in Advanced Microwave Scanning Radiometer-EOS (AMSR-E) measurements. The AMSR-E orbit has equator crossing times near 01:30 and 13 :30 local time, resulting in sampling when near-surface temperature gradients are likely to be large and amplifying the influence of emission depth on effective emitting temperature relative to other factors. AMSR-E measurements are also temporally coincident with Moderate Resolution Imaging Spectroradiometer (MODIS) LST measurements, eliminating time lag as a source of LST uncertainty and reducing LST errors due to undetected clouds. This paper presents monthly global emissivity and emission depth index retrievals for 2003 at 11, 19, 37, and 89 GHz from AMSR-E, MODIS, and SSM/I time series data. Retrieval model fit error, stability, self-consistency, and land surface modeling results provide evidence for the validity of the subsurface emission hypothesis and the retrieval approach. An analysis of emission depth index, emissivity, precipitation, and vegetation index seasonal trends in northern and southern Africa suggests that changes in the emission depth index may be tied to changes in land surface moisture and vegetation conditions

  16. Assimilation of AMSR-E snow water equivalent data in a spatially-lumped snow model

    Science.gov (United States)

    Dziubanski, David J.; Franz, Kristie J.

    2016-09-01

    Accurately initializing snow model states in hydrologic prediction models is important for estimating future snowmelt, water supplies, and flooding potential. While ground-based snow observations give the most reliable information about snowpack conditions, they are spatially limited. In the north-central USA, there are no continual observations of hydrologically critical snow variables. Satellites offer the most likely source of spatial snow data, such as the snow water equivalent (SWE), for this region. In this study, we test the impact of assimilating SWE data from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) instrument into the US National Weather Service (NWS) SNOW17 model for seven watersheds in the Upper Mississippi River basin. The SNOW17 is coupled with the NWS Sacramento Soil Moisture Accounting (SACSMA) model, and both simulated SWE and discharge are evaluated. The ensemble Kalman filter (EnKF) assimilation framework is applied and updating occurs on a daily cycle for water years 2006-2011. Prior to assimilation, AMSR-E data is bias corrected using data from the National Operational Hydrologic Remote Sensing Center (NOHRSC) airborne snow survey program. An average AMSR-E SWE bias of -17.91 mm was found for the study basins. SNOW17 and SAC-SMA model parameters from the North Central River Forecast Center (NCRFC) are used. Compared to a baseline run without assimilation, the SWE assimilation improved discharge for five of the seven study sites, in particular for high discharge magnitudes associated with snow melt runoff. SWE and discharge simulations suggest that the SNOW17 is underestimating SWE and snowmelt rates in the study basins. Deep snow conditions and periods of snowmelt may have introduced error into the assimilation due to difficulty obtaining accurate brightness temperatures under these conditions. Overall results indicate that the AMSR-E data and EnKF are viable and effective solutions for improving simulations

  17. A physics-based statistical algorithm for retrieving land surface temperature from AMSR-E passive microwave data

    Institute of Scientific and Technical Information of China (English)

    MAO KeBiao; SHI JianCheng; LI ZhaoLiang; QIN ZhiHao; LI ManChun; XU Bin

    2007-01-01

    AMSR-E and MODIS are two EOS (Earth Observing System) instruments on board the Aqua satellite. A regression analysis between the brightness of all AMSR-E bands and the MODIS land surface temperature product indicated that the 89 GHz vertical polarization is the best single band to retrieve land surface temperature. According to simulation analysis with AIEM, the difference of different frequencies can eliminate the influence of water in soil and atmosphere, and also the surface roughness partly. The analysis results indicate that the radiation mechanism of surface covered snow is different from others. In order to retrieve land surface temperature more accurately, the land surface should be at least classified into three types: water covered surface, snow covered surface, and non-water and non-snow covered land surface. In order to improve the practicality and accuracy of the algorithm, we built different equations for different ranges of temperature. The average land surface temperature error is about 2-3℃ relative to the MODIS LST product.

  18. A physics-based statistical algorithm for retrieving land surface temperature from AMSR-E passive microwave data

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AMSR-E and MODIS are two EOS (Earth Observing System) instruments on board the Aqua satellite. A regression analysis between the brightness of all AMSR-E bands and the MODIS land surface tem-perature product indicated that the 89 GHz vertical polarization is the best single band to retrieve land surface temperature. According to simulation analysis with AIEM,the difference of different frequen-cies can eliminate the influence of water in soil and atmosphere,and also the surface roughness partly. The analysis results indicate that the radiation mechanism of surface covered snow is different from others. In order to retrieve land surface temperature more accurately,the land surface should be at least classified into three types:water covered surface,snow covered surface,and non-water and non-snow covered land surface. In order to improve the practicality and accuracy of the algorithm,we built different equations for different ranges of temperature. The average land surface temperature er-ror is about 2―3℃ relative to the MODIS LST product.

  19. An Assessment of the Use of AMSR E 10 GHz Data for Soil Moisture Estimation in SMEX02

    Science.gov (United States)

    Hsu, A. Y.; Jackson, T. J.; O'Neill, P. E.

    2003-12-01

    The launch of the Advanced Microwave Scanning Radiometer (AMSR-E) on board the NASA EOS Aqua Satellite has drawn much interest from the scientific community that has been waiting for a low frequency spaceborne microwave radiometer (instrument was developed by the National Space Development Agency of Japan (NASDA) and makes dual-polarized microwave measurements at six frequencies: 6.9, 10.7, 18.7, 23.8, 36.5, and 89 GHz. Early examinations of AMSR-E measurements have shown evidence of extensive Radio-Frequency Interference (RFI) in the 6.9 GHz channels, especially over the continental U.S. Due to the contamination of 6.9 GHz data by RFI, it may be necessary to use the next lowest frequency, 10.7 GHz, for soil moisture retrieval. This frequency has been available on the TRMM Microwave Imager for several years; however, the TRMM sensor only provides data between 38 N to 38 S in latitude whereas AMSR-E provides global coverage. We examined the impact of alternative frequencies on soil moisture retrieval using data from the Soil Moisture Experiments in 2002 (SMEX02). SMEX02 took place in Walnut Creek Watershed and surrounding region of Iowa from June 24 to July 12. The experiment focused on microwave remote sensing of soil moisture in an agricultural setting. Land cover in the Walnut Creek Watershed consists of a patchwork of corn and soybean fields, with some isolated forested zones. This presents a challenge to soil moisture retrieval using AMSR-E 10 GHz data. Extensive vegetation sampling was conducted during SMEX02 to provide information to estimate vegetation parameters required by retrieval algorithm. The maps of AMSR-E 10 GHz data over the SMEX02 area from July 2 to 13 show the decrease of brightness temperature (TB) due to precipitation, although the range is not as profound as expected at L band. The Normalized Difference Polarization Index (NDPI), defined as (TBv-TBh)/(TBv+TBh), computed for various frequencies can be considered as indicators of surface

  20. Impact of Surface Roughness on AMSR-E Sea Ice Products

    Science.gov (United States)

    Stroeve, Julienne C.; Markus, Thorsten; Maslanik, James A.; Cavalieri, Donald J.; Gasiewski, Albin J.; Heinrichs, John F.; Holmgren, Jon; Perovich, Donald K.; Sturm, Matthew

    2006-01-01

    This paper examines the sensitivity of Advanced Microwave Scanning Radiometer (AMSR-E) brightness temperatures (Tbs) to surface roughness by a using radiative transfer model to simulate AMSR-E Tbs as a function of incidence angle at which the surface is viewed. The simulated Tbs are then used to examine the influence that surface roughness has on two operational sea ice algorithms, namely: 1) the National Aeronautics and Space Administration Team (NT) algorithm and 2) the enhanced NT algorithm, as well as the impact of roughness on the AMSR-E snow depth algorithm. Surface snow and ice data collected during the AMSR-Ice03 field campaign held in March 2003 near Barrow, AK, were used to force the radiative transfer model, and resultant modeled Tbs are compared with airborne passive microwave observations from the Polarimetric Scanning Radiometer. Results indicate that passive microwave Tbs are very sensitive even to small variations in incidence angle, which can cause either an over or underestimation of the true amount of sea ice in the pixel area viewed. For example, this paper showed that if the sea ice areas modeled in this paper mere assumed to be completely smooth, sea ice concentrations were underestimated by nearly 14% using the NT sea ice algorithm and by 7% using the enhanced NT algorithm. A comparison of polarization ratios (PRs) at 10.7,18.7, and 37 GHz indicates that each channel responds to different degrees of surface roughness and suggests that the PR at 10.7 GHz can be useful for identifying locations of heavily ridged or rubbled ice. Using the PR at 10.7 GHz to derive an "effective" viewing angle, which is used as a proxy for surface roughness, resulted in more accurate retrievals of sea ice concentration for both algorithms. The AMSR-E snow depth algorithm was found to be extremely sensitive to instrument calibration and sensor viewing angle, and it is concluded that more work is needed to investigate the sensitivity of the gradient ratio at 37 and

  1. Retrieving the antarctic sea-ice concentration based on AMSR-E 89 GHz data

    Institute of Scientific and Technical Information of China (English)

    YU Qinglong; WANG Hui; WAN Liying; BI Haibo

    2013-01-01

    Sea-ice concentration is a key item in global climate change research. Recent progress in remotely sensed sea-ice concentration product has been stimulated by the use of a new sensor, advanced microwave scan-ning radiometer for EOS (AMSR-E), which offers a spatial resolution of 6 km×4 km at 89GHz. A new inver-sion algorithm named LASI (linear ASI) using AMSR-E 89GHz data was proposed and applied in the antarc-tic sea areas. And then comparisons between the LASI ice concentration products and those retrieved by the other two standard algorithms, ASI (arctic radiation and turbulence interaction study sea-ice algorithm) and bootstrap, were made. Both the spatial and temporal variability patterns of ice concentration differ-ences, LASI minus ASI and LASI minus bootstrap, were investigated. Comparative data suggest a high result consistency, especially between LASI and ASI. On the other hand, in order to estimate the LASI ice concen-tration errors introduced by the tie-points uncertainties, a sensitivity analysis was carried out. Additionally an LASI algorithm error estimation based on the field measurements was also completed. The errors suggest that the moderate to high ice concentration areas (>70%) are less affected (never exceeding 10%) than those in the low ice concentration. LASI and ASI consume 75 and 112 s respectively when processing the same AMSR-E time series thourghout the year 2010. To conclude, by using the LASI algorithm, not only the sea-ice concentration can be retrieved with at least an equal quality as that of the two extensively demonstrated operational algorithms, ASI and bootstrap, but also in a more efficient way than ASI.

  2. A comparison of Argo nominal surface and near-surface temperature for validation of AMSR-E SST

    Science.gov (United States)

    Liu, Zenghong; Chen, Xingrong; Sun, Chaohui; Wu, Xiaofen; Lu, Shaolei

    2016-06-01

    Satellite SST (sea surface temperature) from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) is compared with in situ temperature observations from Argo profiling floats over the global oceans to evaluate the advantages of Argo NST (near-surface temperature: water temperature less than 1 m from the surface). By comparing Argo nominal surface temperature (~5 m) with its NST, a diurnal cycle caused by daytime warming and nighttime cooling was found, along with a maximum warming of 0.08±0.36°C during 14:00-15:00 local time. Further comparisons between Argo 5-m temperature/Argo NST and AMSR-E SST retrievals related to wind speed, columnar water vapor, and columnar cloud water indicate warming biases at low wind speed (28 mm during daytime. The warming tendency is more remarkable for AMSR-E SST/Argo 5-m temperature compared with AMSR-E SST/Argo NST, owing to the effect of diurnal warming. This effect of diurnal warming events should be excluded before validation for microwave SST retrievals. Both AMSR-E nighttime SST/Argo 5-m temperature and nighttime SST/Argo NST show generally good agreement, independent of wind speed and columnar water vapor. From our analysis, Argo NST data demonstrated their advantages for validation of satellite-retrieved SST.

  3. Retrievals of All-Weather Daily Air Temperature Using MODIS and AMSR-E Data

    Directory of Open Access Journals (Sweden)

    Keunchang Jang

    2014-09-01

    Full Text Available Satellite optical-infrared remote sensing from the Moderate Resolution Imaging Spectroradiometer (MODIS provides effective air temperature (Ta retrieval at a spatial resolution of 5 km. However, frequent cloud cover can result in substantial signal loss and remote sensing retrieval error in MODIS Ta. We presented a simple pixel-wise empirical regression method combining synergistic information from MODIS Ta and 37 GHz frequency brightness temperature (Tb retrievals from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E for estimating surface level Ta under both clear and cloudy sky conditions in the United States for 2006. The instantaneous Ta retrievals showed favorable agreement with in situ air temperature records from 40 AmeriFlux tower sites; mean R2 correspondence was 86.5 and 82.7 percent, while root mean square errors (RMSE for the Ta retrievals were 4.58 K and 4.99 K for clear and cloudy sky conditions, respectively. Daily mean Ta was estimated using the instantaneous Ta retrievals from day/night overpasses, and showed favorable agreement with local tower measurements (R2 = 0.88; RMSE = 3.48 K. The results of this study indicate that the combination of MODIS and AMSR-E sensor data can produce Ta retrievals with reasonable accuracy and relatively fine spatial resolution (~5 km for clear and cloudy sky conditions.

  4. Global-Scale Evaluation of Roughness Effects on C-Band AMSR-E Observations

    Directory of Open Access Journals (Sweden)

    Shu Wang

    2015-05-01

    Full Text Available Quantifying roughness effects on ground surface emissivity is an important step in obtaining high-quality soil moisture products from large-scale passive microwave sensors. In this study, we used a semi-empirical method to evaluate roughness effects (parameterized here by the  parameter on a global scale from AMSR-E (Advanced Microwave Scanning Radiometer for EOS observations. AMSR-E brightness temperatures at 6.9 GHz obtained from January 2009 to September 2011, together with estimations of soil moisture from the SMOS (Soil Moisture and Ocean Salinity L3 products and of soil temperature from ECMWF’s (European Centre for Medium-range Weather Forecasting were used as inputs in a retrieval process. In the first step, we retrieved a parameter (referred to as the  parameter accounting for the combined effects of roughness and vegetation. Then, global MODIS NDVI data were used to decouple the effects of vegetation from those of surface roughness. Finally, global maps of the Hr parameters were produced and discussed. Initial results showed that some spatial patterns in the  values could be associated with the main vegetation types (higher values of  were retrieved generally in forested regions, intermediate values were obtained over crops and grasslands, and lower values were obtained over shrubs and desert and topography. For instance, over the USA, lower values of  were retrieved in relatively flat regions while relatively higher values were retrieved in hilly regions.

  5. Land Surface Microwave Emissivities Derived from AMSR-E and MODIS Measurements with Advanced Quality Control

    Science.gov (United States)

    Moncet, Jean-Luc; Liang, Pan; Galantowicz, John F.; Lipton, Alan E.; Uymin, Gennady; Prigent, Catherine; Grassotti, Christopher

    2011-01-01

    A microwave emissivity database has been developed with data from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) and with ancillary land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the same Aqua spacecraft. The primary intended application of the database is to provide surface emissivity constraints in atmospheric and surface property retrieval or assimilation. An additional application is to serve as a dynamic indicator of land surface properties relevant to climate change monitoring. The precision of the emissivity data is estimated to be significantly better than in prior databases from other sensors due to the precise collocation with high-quality MODIS LST data and due to the quality control features of our data analysis system. The accuracy of the emissivities in deserts and semi-arid regions is enhanced by applying, in those regions, a version of the emissivity retrieval algorithm that accounts for the penetration of microwave radiation through dry soil with diurnally varying vertical temperature gradients. These results suggest that this penetration effect is more widespread and more significant to interpretation of passive microwave measurements than had been previously established. Emissivity coverage in areas where persistent cloudiness interferes with the availability of MODIS LST data is achieved using a classification-based method to spread emissivity data from less-cloudy areas that have similar microwave surface properties. Evaluations and analyses of the emissivity products over homogeneous snow-free areas are presented, including application to retrieval of soil temperature profiles. Spatial inhomogeneities are the largest in the vicinity of large water bodies due to the large water/land emissivity contrast and give rise to large apparent temporal variability in the retrieved emissivities when satellite footprint locations vary over time. This issue will be dealt with in the future by

  6. Remote sensing of multiyear sea ice using AMSR-E 89 GHz data

    Science.gov (United States)

    Heygster, Georg; Wang, Huanhuan

    Sea ice plays an important role in the global climate system. The change of sea ice can strongly influence the atmosphere in Arctic which will enhance the global climate change. Passive microwave remote sensing has been used for sea ice detection for more than thirty years since microwave emission penetrates clouds and is independent of day/night condition. There are already several well-validated sea ice retrieval algorithms such as NASA TEAM and Bootstrap algorithm, but they used the lower frequencies with lower resolution. The new radiometer AMSR-E has the advantage of higher horizontal resolution than the previous SSM/I radiometer, especially at 89 GHz. The total ice concentration retrieval algorithm using this data has been well established while for multiyear ice(MYI) there has been few research until now. In this work, the AMSR-E 89 GHz brightness temperature data is used to retrieval MYI concentration. AMSR-E 89 GHz brightness temperature from three test regions are analyzed: first-year ice, multiyear ice and open water. Based on their different response to brightness temperature and polarization difference, a new algorithm is developed and the daily maps and time series of both total ice and MYI areas in the Arctic are calculated for the whole year 2007. Comparing to results from the NASA TEAM algorithm and the Lomax's algorithm, our total ice agrees quite well with the others while the MYI results still differ. Lomax's MYI gives highest value and strongest increasing in winter which is unphysical. Our MYI results also show increasing during winter but are much closer to the NASA TEAM results. In addition, both our algorithm and the NASA TEAM algorithm show MYI in regions which should be clear of MYI through the whole year. It would be a plausible explanation that both MYI algorithms in addition to MYI also detect refrozen first-year ice, but to different extents. Excluding these cases from the MYI retrievals remains a task for future work.

  7. Applications of an AMSR-E RFI Detection and Correction Algorithm in 1-DVAR over Land

    Institute of Scientific and Technical Information of China (English)

    吴莹; 翁富忠

    2014-01-01

    Land retrievals using passive microwave radiometers are sensitive to small fluctuations in land brightness temperatures. As such, the radio-frequency interference (RFI) signals emanating from man-made microwave radiation transmitters can result in large errors in land retrievals. RFI in C-and X-band channels can con-taminate remotely sensed measurements, as experienced with the Advanced Microwave Scanning Radiometer (AMSR-E) and the WindSat sensor. In this work, applications of an RFI detection and correction algorithm in retrieving a comprehensive suite of geophysical parameters from AMSR-E measurements using the one-dimensional variational retrieval (1-DVAR) method are described. The results indicate that the values of retrieved parameters, such as land skin temperature (LST), over these areas contaminated by RFI are much higher than those from the global data assimilation system (GDAS) products. The results also indicate that the differences between new retrievals and GDAS products are decreased evidently through taking into account the RFI correction algorithm. In addition, the convergence metric (χ2) of 1-DVAR is found to be a new method for identifying regions where land retrievals are affected by RFI. For example, in those regions with much stronger RFI, such as Europe and Japan, χ2 of 1-DVAR is so large that convergence cannot be reached and retrieval results may not be reliable or cannot be obtained. Furthermore,χ2 also decreases with the RFI-corrected algorithm for those regions with moderate or weak RFI. The results of RFI detected byχ2 are almost consistent with those identified by the spectral difference method.

  8. A Comparison of Snow Depth on Sea Ice Retrievals Using Airborne Altimeters and an AMSR-E Simulator

    Science.gov (United States)

    Cavalieri, D. J.; Marksu, T.; Ivanoff, A.; Miller, J. A.; Brucker, L.; Sturm, M.; Maslanik, J. A.; Heinrichs, J. F.; Gasiewski, A.; Leuschen, C.; Krabill, W.; Sonntag, J.

    2011-01-01

    A comparison of snow depths on sea ice was made using airborne altimeters and an Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) simulator. The data were collected during the March 2006 National Aeronautics and Space Administration (NASA) Arctic field campaign utilizing the NASA P-3B aircraft. The campaign consisted of an initial series of coordinated surface and aircraft measurements over Elson Lagoon, Alaska and adjacent seas followed by a series of large-scale (100 km ? 50 km) coordinated aircraft and AMSR-E snow depth measurements over portions of the Chukchi and Beaufort seas. This paper focuses on the latter part of the campaign. The P-3B aircraft carried the University of Colorado Polarimetric Scanning Radiometer (PSR-A), the NASA Wallops Airborne Topographic Mapper (ATM) lidar altimeter, and the University of Kansas Delay-Doppler (D2P) radar altimeter. The PSR-A was used as an AMSR-E simulator, whereas the ATM and D2P altimeters were used in combination to provide an independent estimate of snow depth. Results of a comparison between the altimeter-derived snow depths and the equivalent AMSR-E snow depths using PSR-A brightness temperatures calibrated relative to AMSR-E are presented. Data collected over a frozen coastal polynya were used to intercalibrate the ATM and D2P altimeters before estimating an altimeter snow depth. Results show that the mean difference between the PSR and altimeter snow depths is -2.4 cm (PSR minus altimeter) with a standard deviation of 7.7 cm. The RMS difference is 8.0 cm. The overall correlation between the two snow depth data sets is 0.59.

  9. Potential for Monitoring Snow Cover in Boreal Forests by Combining MODIS Snow Cover and AMSR-E SWE Maps

    Science.gov (United States)

    Riggs, George A.; Hall, Dorothy K.; Foster, James L.

    2009-01-01

    Monitoring of snow cover extent and snow water equivalent (SWE) in boreal forests is important for determining the amount of potential runoff and beginning date of snowmelt. The great expanse of the boreal forest necessitates the use of satellite measurements to monitor snow cover. Snow cover in the boreal forest can be mapped with either the Moderate Resolution Imaging Spectroradiometer (MODIS) or the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) microwave instrument. The extent of snow cover is estimated from the MODIS data and SWE is estimated from the AMSR-E. Environmental limitations affect both sensors in different ways to limit their ability to detect snow in some situations. Forest density, snow wetness, and snow depth are factors that limit the effectiveness of both sensors for snow detection. Cloud cover is a significant hindrance to monitoring snow cover extent Using MODIS but is not a hindrance to the use of the AMSR-E. These limitations could be mitigated by combining MODIS and AMSR-E data to allow for improved interpretation of snow cover extent and SWE on a daily basis and provide temporal continuity of snow mapping across the boreal forest regions in Canada. The purpose of this study is to investigate if temporal monitoring of snow cover using a combination of MODIS and AMSR-E data could yield a better interpretation of changing snow cover conditions. The MODIS snow mapping algorithm is based on snow detection using the Normalized Difference Snow Index (NDSI) and the Normalized Difference Vegetation Index (NDVI) to enhance snow detection in dense vegetation. (Other spectral threshold tests are also used to map snow using MODIS.) Snow cover under a forest canopy may have an effect on the NDVI thus we use the NDVI in snow detection. A MODIS snow fraction product is also generated but not used in this study. In this study the NDSI and NDVI components of the snow mapping algorithm were calculated and analyzed to determine how they changed

  10. The sensitivity of land emissivity estimates from AMSR-E at C and X bands to surface properties

    Directory of Open Access Journals (Sweden)

    H. Norouzi

    2011-11-01

    Full Text Available Microwave observations at low frequencies exhibit more sensitivity to surface and subsurface properties with little interference from the atmosphere. The objective of this study is to develop a global land emissivity product using passive microwave observations from the Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E and to investigate its sensitivity to land surface properties. The developed product complements existing land emissivity products from SSM/I and AMSU by adding land emissivity estimates at two lower frequencies, 6.9 and 10.65 GHz (C- and X-band, respectively. Observations at these low frequencies penetrate deeper into the soil layer. Ancillary data used in the analysis, such as surface skin temperature and cloud mask, are obtained from International Satellite Cloud Climatology Project (ISCCP. Atmospheric properties are obtained from the TIROS Operational Vertical Sounder (TOVS observations to determine the small upwelling and downwelling atmospheric emissions as well as the atmospheric transmission. A sensitivity test confirms the small effect of the atmosphere but shows that skin temperature accuracy can significantly affect emissivity estimates. Retrieved emissivities at C- and X-bands and their polarization differences exhibit similar patterns of variation with changes in land cover type, soil moisture, and vegetation density as seen at SSM/I-like frequencies (Ka and Ku bands. The emissivity maps from AMSR-E at these higher frequencies agree reasonably well with the existing SSM/I-based product. The inherent discrepancy introduced by the difference between SSM/I and AMSR-E frequencies, incidence angles, and calibration has been assessed. Significantly greater standard deviation of estimated emissivities compared to SSM/I land emissivity product was found over desert regions. Large differences between emissivity estimates from ascending and descending overpasses were found at lower frequencies due to the

  11. Detection and characterization of drizzle cells within marine stratocumulus using AMSR-E 89 GHz passive microwave measurements

    Directory of Open Access Journals (Sweden)

    M. A. Miller

    2012-07-01

    Full Text Available This empirical study demonstrates the feasibility of using 89 GHz Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E passive microwave brightness temperature data to detect heavily drizzling cells within marine stratocumulus. A binary heavy drizzle product is described that can be used to determine areal and feature statistics of drizzle cells within the major marine stratocumulus regions. Current satellite liquid water path (LWP and cloud radar products capable of detecting drizzle are either lacking in resolution (AMSR-E LWP, diurnal coverage (MODIS LWP, or spatial coverage (CloudSat. The AMSR-E 89 GHz data set at 6 × 4 km spatial resolution is sufficient for resolving individual heavily drizzling cells. Radiant emission at 89 GHz by liquid-water cloud and precipitation particles from drizzling cells in marine stratocumulus regions yields local maxima in brightness temperature against an otherwise cloud-free background brightness temperature. The background brightness temperature is primarily constrained by column-integrated water vapor and sea surface temperature. Clouds containing ice are screened out. Once heavily drizzling pixels are identified, connected pixels are grouped into discrete drizzle cell features. The identified drizzle cells are used in turn to determine several spatial statistics for each satellite scene, including drizzle cell number and size distribution. The identification of heavily drizzling cells within marine stratocumulus regions with satellite data facilitates analysis of seasonal and regional drizzle cell occurrence and the interrelation between drizzle and changes in cloud fraction.

  12. An algorithm to detect sea ice leads using AMSR-E passive microwave imagery

    Directory of Open Access Journals (Sweden)

    J. Röhrs

    2010-02-01

    Full Text Available Leads are major sites of energy fluxes and brine releases at the air-ocean interface of sea ice covered oceans. This study presents an algorithm to detect leads that are broader than 3 km in the entire Arctic Ocean. The algorithm detected 50% of the lead area that is visible in optical satellite images. Passive microwave imagery from the Advanced Microwave Scanning Radiometer – Earth Observation System (AMSR-E is used, allowing daily observations that are independent of daylight or cloud conditions. Using unique signatures of thin ice in the brightness temperature ratio between the 89 GHz and 19 GHz channels, the algorithm allowed to detect thin ice features in the ice cover and is optimized to detect leads. Leads were mapped for the period from 2002–2009 excluding the summer months. Several frequently reoccurring large scale lead patterns were found, especially in regions where sea ice is known to drift out of the Arctic Ocean. The maximum lead occurrence in the Arctic is located in the Beaufort Sea, low lead occurrence was found in the inner Arctic Ocean close to the North Pole.

  13. A COMPARISON BETWEEN TWO ALGORITHMS FOR THE RETRIEVAL OF SOIL MOISTURE USING AMSR-E DATA

    Directory of Open Access Journals (Sweden)

    Simonetta ePaloscia

    2015-04-01

    Full Text Available A comparison between two algorithms for estimating soil moisture with microwave satellite data was carried out by using the datasets collected on the four Agricultural Research Service (ARS watershed sites in the US from 2002 to 2009. These sites collectively represent a wide range of ground conditions and precipitation regimes (from natural to agricultural surfaces and from desert to humid regions and provide long-term in-situ data. One of the algorithms is the artificial neural network-based algorithm developed by the Institute of Applied Physics of the National Research Council (IFAC-CNR (HydroAlgo and the second one is the Single Channel Algorithm (SCA developed by USDA-ARS (US Department of Agriculture-Agricultural Research Service. Both algorithms are based on the same radiative transfer equations but are implemented very differently. Both made use of datasets provided by the Japanese Aerospace Exploration Agency (JAXA, within the framework of Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E and Global Change Observation Mission–Water GCOM/AMSR-2 programs. Results demonstrated that both algorithms perform better than the mission specified accuracy, with Root Mean Square Error (RMSE ≤0.06 m3/m3 and Bias <0.02 m3/m3. These results expand on previous investigations using different algorithms and sites. The novelty of the paper consists of the fact that it is the first intercomparison of the HydroAlgo algorithm with a more traditional retrieval algorithm, which offers an approach to higher spatial resolution products.

  14. Identifying AMSR-E radio-frequency interference over winter land

    Science.gov (United States)

    Zhang, Sibo; Guan, Li

    2015-09-01

    Satellite microwave emission mixed with signals from active sensors is referred to as radio-frequency interference (RFI). RFI affects greatly the quality of data and retrieval products from space-borne microwave radiometry. An accurate RFI detection will not only enhance geophysical retrievals over land but also provide evidence of the much-needed protection of the microwave frequency band for satellite remote sensing technologies. It is difficult to detect RFI from space-borne microwave radiometer data over winter land, because RFI signals are usually mixed with snow in mid-high latitudes. A modified principal component analysis (PCA) method is proposed in this paper for detecting microwave low frequency RFI signals. Only three original variables, one RFI index (sensitive to RFI signal) and two scattering indices (sensitive to snow scattering), are included in the vector for principal component analysis in this modified method instead of the nine or seven RFI index original variables used in a normal PCA algorithm. The principal component with higher correlation and contribution to the original RFI index is the RFI-related principal component. In the absence of a reliable validation data set of the "true" RFI, the consistency in the identified RFI distribution obtained from this method compared to other independent methods, such as the spectral difference method, the normalized PCA method, and the double PCA method, give confidence to the RFI signals' identification over land. The simple and reliable modified PCA method could successfully detect RFI not only in summer but also in winter AMSR-E data.

  15. A study of multiyear ice concentration retrieval algorithms using AMSR-E data

    Institute of Scientific and Technical Information of China (English)

    HAO Guanghua; SU Jie

    2015-01-01

    In recent years, the rapid decline of Arctic sea ice area (SIA) and sea ice extent (SIE), especially for the multiyear (MY) ice, has led to significant effect on climate change. The accurate retrieval of MY ice concentration retrieval is very important and challenging to understand the ongoing changes. Three MY ice concentration retrieval algorithms were systematically evaluated. A similar total ice concentration was yielded by these algorithms, while the retrieved MY sea ice concentrations differs from each other. The MY SIA derived from NASA TEAM algorithm is relatively stable. Other two algorithms created seasonal fluctuations of MY SIA, particularly in autumn and winter. In this paper, we proposed an ice concentration retrieval algorithm, which developed the NASA TEAM algorithm by adding to use AMSR-E 6.9 GHz brightness temperature data and sea ice concentration using 89.0 GHz data. Comparison with the reference MY SIA from reference MY ice, indicates that the mean difference and root mean square (rms) difference of MY SIA derived from the algorithm of this study are 0.65×106 km2 and 0.69×106 km2 during January to March, –0.06×106 km2 and 0.14×106 km2 during September to December respectively. Comparison with MY SIE obtained from weekly ice age data provided by University of Colorado show that, the mean difference and rms difference are 0.69×106 km2 and 0.84×106 km2, respectively. The developed algorithm proposed in this study has smaller difference compared with the reference MY ice and MY SIE from ice age data than the Wang’s, Lomax’ and NASA TEAM algorithms.

  16. SST, Aqua AMSR-E, 0.25 degrees, Global

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA OceanWatch provides sea surface temperature (SST) products derived from microwave sensors, which can measure ocean temperatures even in the presence of clouds....

  17. Detection and characterization of heavy drizzle cells within subtropical marine stratocumulus using AMSR-E 89-GHz passive microwave measurements

    Directory of Open Access Journals (Sweden)

    M. A. Miller

    2013-01-01

    Full Text Available This empirical study demonstrates the feasibility of using 89-GHz Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E passive microwave brightness temperature data to detect heavily drizzling cells within subtropical marine stratocumulus. For the purpose of this paper, we define heavily drizzling cells as areas ≥ 6 km × 4 km with C-band Z > 0 dBZ; equivalent to > 0.084 mm h−1. A binary heavy drizzle product is described that can be used to determine areal and feature statistics of drizzle cells within the major marine stratocumulus regions. Current satellite liquid water path (LWP and cloud radar products capable of detecting drizzle are either lacking in resolution (AMSR-E LWP, diurnal coverage (MODIS LWP, or spatial coverage (CloudSat. The AMSR-E 89-GHz data set at 6 km × 4 km spatial resolution is sufficient for resolving individual heavily drizzling cells. Radiant emission at 89 GHz by liquid-water cloud and precipitation particles from drizzling cells in marine stratocumulus regions yields local maxima in brightness temperature against an otherwise cloud-free background brightness temperature. The background brightness temperature is primarily constrained by column-integrated water vapor for moderate sea surface temperatures. Clouds containing ice are screened out. Once heavily drizzling pixels are identified, connected pixels are grouped into discrete drizzle cell features. The identified drizzle cells are used in turn to determine several spatial statistics for each satellite scene, including drizzle cell number and size distribution. The identification of heavily drizzling cells within marine stratocumulus regions with satellite data facilitates analysis of seasonal and regional drizzle cell occurrence and the interrelation between drizzle and changes in cloud fraction.

  18. The sensitivity of land emissivity estimates from AMSR-E at C and X bands to surface properties

    Directory of Open Access Journals (Sweden)

    H. Norouzi

    2011-06-01

    Full Text Available Microwave observations at low frequencies exhibit more sensitivity to surface and subsurface properties with little interference from the atmosphere. The objective of this study is to develop a global land emissivity product using passive microwave observations from the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E and to investigate its sensitivity to land surface properties. The developed product complements existing land emissivity products from SSM/I and AMSU by adding land emissivity estimates at two lower frequencies, 6.9 and 10.65 GHz (C- and X-band, respectively. Observations at these low frequencies penetrate deeper into the soil layer. Ancillary data used in the analysis, such as surface skin temperature and cloud mask, are obtained from International Satellite Cloud Climatology Project (ISCCP. Atmospheric properties are obtained from the TIROS Operational Vertical Sounder (TOVS observations to determine the small upwelling and downwelling atmospheric emissions as well as the atmospheric transmission. A sensitivity test confirms the small effect of the atmosphere but shows that skin temperature accuracy can significantly affect emissivity estimates. Retrieved emissivities at C- and X-bands and their polarization differences exhibit similar patterns of variation with changes in land cover type, soil moisture, and vegetation density as seen at SSM/I-like frequencies (Ka and Ku bands. The emissivity maps from AMSR-E at these higher frequencies agree reasonably well with the existing SSM/I-based product. The inherent but small discrepancy introduced by the difference between SSM/I and AMSR-E frequencies and incidence angles has been examined and found to be small. Large differences between emissivity estimates from ascending and descending overpasses were found at the lower frequencies due to the inconsistency between the thermal IR skin temperatures and passive microwave brightness temperatures which can come from

  19. Results from Assimilating AMSR-E Soil Moisture Estimates into a Land Surface Model Using an Ensemble Kalman Filter in the Land Information System

    Science.gov (United States)

    Blankenship, Clay B.; Crosson, William L.; Case, Jonathan L.; Hale, Robert

    2010-01-01

    Improve simulations of soil moisture/temperature, and consequently boundary layer states and processes, by assimilating AMSR-E soil moisture estimates into a coupled land surface-mesoscale model Provide a new land surface model as an option in the Land Information System (LIS)

  20. Detection of radio-frequency interference signals from AMSR-E data over the United States with snow cover

    Science.gov (United States)

    Feng, Chengcheng; Zou, Xiaolei; Zhao, Juan

    2016-06-01

    Radio Frequency Interference (RFI) causes severe contamination to passive and active microwave sensing observations and corresponding retrieval products. RFI signals should be detected and filtered before applying the microwave data to retrieval and data assimilation. It is difficult to detect RFI over land surfaces covered by snow because of the scattering effect of snow surface. The double principal component analysis (DPCA) method is adopted in this study, and its ability in identifying RFI signals in AMSR-E data over snow covered regions is investigated. Results show that the DPCA method can detect RFI signals effectively in spite of the impact of snow scattering, and the detected RFI signals persistent over time. Compared to other methods, such as PCA and normalized PCA, DPCA is more robust and suitable for operational application.

  1. Estimation of Land Surface Temperature through Blending MODIS and AMSR-E Data with the Bayesian Maximum Entropy Method

    Directory of Open Access Journals (Sweden)

    Xiaokang Kou

    2016-01-01

    Full Text Available Land surface temperature (LST plays a major role in the study of surface energy balances. Remote sensing techniques provide ways to monitor LST at large scales. However, due to atmospheric influences, significant missing data exist in LST products retrieved from satellite thermal infrared (TIR remotely sensed data. Although passive microwaves (PMWs are able to overcome these atmospheric influences while estimating LST, the data are constrained by low spatial resolution. In this study, to obtain complete and high-quality LST data, the Bayesian Maximum Entropy (BME method was introduced to merge 0.01° and 0.25° LSTs inversed from MODIS and AMSR-E data, respectively. The result showed that the missing LSTs in cloudy pixels were filled completely, and the availability of merged LSTs reaches 100%. Because the depths of LST and soil temperature measurements are different, before validating the merged LST, the station measurements were calibrated with an empirical equation between MODIS LST and 0~5 cm soil temperatures. The results showed that the accuracy of merged LSTs increased with the increasing quantity of utilized data, and as the availability of utilized data increased from 25.2% to 91.4%, the RMSEs of the merged data decreased from 4.53 °C to 2.31 °C. In addition, compared with the filling gap method in which MODIS LST gaps were filled with AMSR-E LST directly, the merged LSTs from the BME method showed better spatial continuity. The different penetration depths of TIR and PMWs may influence fusion performance and still require further studies.

  2. Retrieval of sea surface temperature from AMSR-E and MODIS in the Northern Indian Ocean%基于AMSR-E与MODIS数据海表面温度遥感反演研究

    Institute of Scientific and Technical Information of China (English)

    霍文娟; 韩震

    2013-01-01

    海洋表面温度是海洋环境的重要参数.遥感技术是进行海表面温度研究的有效手段之一.以印度洋北部海域为研究区域,利用Aqua卫星上的微波数据(AMSR-E)和光学数据(MODIS),进行了海表温度反演研究.首先对AMSR-E L2A数据和MODIS L1B数据进行预处理,然后将AMSR-E的各极化通道亮温数据与实测海表温度进行相关性分析,通过多元线性回归建立AMSR-E海表温度的反演模型,而MODIS海表温度则通过采用线性多通道算法得到,最后以AMSR-E亮温数据为主,MODIS海表温度数据为辅,采用多元线性回归的方法建立了海表温度反演模型.利用该模型反演印度洋北部海域海表温度,反演结果与实测数据相比,其均方根误差为0.323 97℃.研究亮点:以印度洋北部海域为研究区域,综合利用同一卫星(AQUA)上的微波数据(AMSR-E)和光学数据(MODIS)来反演海洋表面温度,在一定程度上结合微波遥感和热红外遥感各自的优势,实现全天候全海域的海洋表面温度遥感观测,反演结果的精度也略有提高.

  3. GRACE and AMSR-E-based estimates of winter season solid precipitation accumulation in the Arctic drainage region

    Science.gov (United States)

    Seo, Ki-Weon; Ryu, Dongryeol; Kim, Baek-Min; Waliser, Duane E.; Tian, Baijun; Eom, Jooyoung

    2010-10-01

    Solid precipitation plays a major role in controlling the winter hydrological cycle and spring discharge in the Arctic region. However, it has not been well documented due to sharply decreasing numbers of precipitation gauges, gauge measurement biases, as well as limitations of conventional satellite methods in high latitudes. In this study, we document the winter season solid precipitation accumulation in the Arctic region using the latest new satellite measurements from the Gravity Recovery and Climate Experiment (GRACE) and the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E). GRACE measures the winter total water (mainly from snow water equivalent (SWE)) storage change through gravity changes while AMSR-E measures the winter SWE through passive microwave measurements. The GRACE and AMSR-E measurements are combined with in situ and numerical model estimates of discharge and evapotranspiration to estimate the winter season solid precipitation accumulation in the Arctic region using the water budget equation. These two satellite-based estimates are then compared to the conventional estimates from two global precipitation products, such as the Global Precipitation Climatology Project (GPCP) and Climate Prediction Center's Merged Analysis of Precipitation (CMAP), and three reanalyses, the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis, the European Centre for Medium-Range Weather Forecasts' ERA-Interim, and the Japan Meteorological Agency's Climate Data Assimilation System (JCDAS) reanalysis. The GRACE-based estimate is very close to the GPCP and ERA-Interim estimates. The AMSR-E-based estimate is the most different from the other estimates. This GRACE-based measurement of winter season solid precipitation accumulation can provide a new valuable benchmark to understand the hydrological cycle, to validate and evaluate the model simulation, and to improve data assimilation in the

  4. Long time series of soil moisture obtained using neural networks: application to AMSR-E and SMOS

    Science.gov (United States)

    Rodriguez-Fernandez, Nemesio J.; Kerr, Yann H.; de Jeu, Rcihard A. M.; van der Schalie, Robin; Wigneron, Jean Pierre; Ayaari, Amen al; Dolman, Han; Drusch, Matthias; Mecklenburg, Sussane

    2015-04-01

    The Soil Moisture and Ocean Salinity (SMOS) satellite is the first mission specifically designed to measure soil moisture (hereafter SM) from space. The instrument on-board SMOS is a L-band aperture synthesis radiometer, with full-polarization and multi-angular capabilities (Mecklenburg et al. 2012). The operational SM retrieval algorithm is based on a physical model (Kerr et al. 2012). In addition, Rodriguez-Fernandez et al. (2014) have recently implemented an inverse model based in neural networks using the approach of Aires & Prigent (2006), which consists in training the neural networks with numerical weather prediction models (ECMWF, Balsamo et al. 2009). In the context of an ESA funded project (de Jeu et al, this conference, session CL 5.7), we have studied this neural network approach to create a consistent soil moisture dataset from 2003 to 2014 using NASA/JAXA Advanced Scanning Microwave Radiometer (AMSR-E) and ESA SMOS radiometers as input data. Two neural networks algorithms have been defined and optimized using AMSR-E or SMOS as input data in the periods 2003-Oct 2011 and 2010-2014, respectively. The two missions overlapping period has been used to demonstrate the consistency of the SM dataset produced with both algorithms by comparing monthly averages of SM and by comparing with time series of in situ measurements at selected locations and other SM products such as the SMOS operational SM, ECMWF model SM, and AMSR-E LPRM SM (Owe et al. 2008). Finally, the long time series of SM obtained with neural networks will be compared to in-situ measurements and ECMWF ERA-Interim SM at selected locations. This long-term soil moisture dataset can be used for hydrological and climate applications and it is the first step towards a longer dataset which will include additional sensors. References Aires, F. & Prigent, C. Toward a new generation of satellite surface products? Journal of Geophysical Research: Atmospheres (1984--2012), Wiley Online Library, 2006, 11

  5. Evaluation of Enhanced High Resolution MODIS/AMSR-E SSTs and the Impact on Regional Weather Forecast

    Science.gov (United States)

    Schiferl, Luke D.; Fuell, Kevin K.; Case, Jonathan L.; Jedlovec, Gary J.

    2010-01-01

    Over the last few years, the NASA Short-term Prediction Research and Transition (SPoRT) Center has been generating a 1-km sea surface temperature (SST) composite derived from retrievals of the Moderate Resolution Imaging Spectroradiometer (MODIS) for use in operational diagnostics and regional model initialization. With the assumption that the day-to-day variation in the SST is nominal, individual MODIS passes aboard the Earth Observing System (EOS) Aqua and Terra satellites are used to create and update four composite SST products each day at 0400, 0700, 1600, and 1900 UTC, valid over the western Atlantic and Caribbean waters. A six month study from February to August 2007 over the marine areas surrounding southern Florida was conducted to compare the use of the MODIS SST composite versus the Real-Time Global SST analysis to initialize the Weather Research and Forecasting (WRF) model. Substantial changes in the forecast heat fluxes were seen at times in the marine boundary layer, but relatively little overall improvement was measured in the sensible weather elements. The limited improvement in the WRF model forecasts could be attributed to the diurnal changes in SST seen in the MODIS SST composites but not accounted for by the model. Furthermore, cloud contamination caused extended periods when individual passes of MODIS were unable to update the SSTs, leading to substantial SST latency and a cool bias during the early summer months. In order to alleviate the latency problems, the SPoRT Center recently enhanced its MODIS SST composite by incorporating information from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) instruments as well as the Operational Sea Surface Temperature and Sea Ice Analysis. These enhancements substantially decreased the latency due to cloud cover and improved the bias and correlation of the composites at available marine point observations. While these enhancements improved upon the modeled cold bias using the original MODIS SSTs

  6. MODIS_LST与AMSR-E_BT的相关性及地表温度反演%The Correlation Analysis Between MODIS_LST and AMSR-E_BT and Study of LST Retrieval Method

    Institute of Scientific and Technical Information of China (English)

    时洪涛; 宋冬梅; 单新建; 崔建勇; 臧琳; 沈晨; 屈春燕; 任鹏; 邵红梅

    2016-01-01

    本文以2007年和2008年MODIS每日地表温度(LST)数据及AMSR-E地表亮温(BT)数据为研究对象,结合土地覆盖类型数据,统计分析MODIS_LST与AMSR-E_BT在不同土地覆盖类型、频率和极化方式条件下的相关性.结果表明,频率在18.7、23.8和36.5 GHz的AMSR-E-BT与MODIS_LST的相关性较大,且在垂直极化通道上的相关性较在水平极化上大;不同土地覆盖类型,与MODIS_LST相关性较大所对应的AMSR-E微波通道不同.同时,考虑混合像元问题对相关性的影响,对25种不同地物类型组合下MODIS_LST与AMSR-E-BT的相关性进行统计分析,发现混合像元中地物类型越多,则二者相关性越小.最后,采用多元线性回归分析法,根据不同土地覆盖类型建立反演回归模型,对部分研究区域MODIS-LST进行反演,误差平均在±3.15 K以内,与不考虑下垫面覆盖的模型比较,反演MODIS_LST精度平均提高了1.5 K.%By taking MODIS daily land surface temperature (LST) data and AMSR-E brightness temperature (BT) data from 2007 to 2008 as the input, combining with the land cover type data, the statistics and analysis of the relativity between MODIS_LST and AMSR-E_BT in different land cover types, channels and polarization ways are produced. Based on the International Geosphere-Bio-sphere Program (IGBP) vegetation classification scheme, land cover data is re-classified into seven types, including water, forest land, grass land, farmland, urban land, desert land and other land cover types. The statistical result shows that the correlation is ap-parent between MODIS_LST and AMSR-E_BT in 18.7 GHz, 23.8 GHz and 36.5 GHz channel, and it reveals a higher correlation in the vertical channel compared to the horizontal channel. Moreover, this paper finds out that the microwave channel of AMSR-E_BT, which has the highest relativity with MODIS-LST, is different with respect to different land cover types. In addition, by con-sidering the impact of mixed pixel, this

  7. Evaluation of AMSR-E Derived Soil Moisture over Northern China

    Institute of Scientific and Technical Information of China (English)

    ZHANG An-Zhi; JIA Gen-Suo; WANG He-Song; ZHAO Tian-Bao; FENG Jin-Ming; MA Zhu-Guo

    2011-01-01

    In this study, the authors evaluated two remotely sensed surface soil moisture datasets derived from the Advanced Microwave Scanning Radiometer of the Earth Observing System (AMSR-E) over northern China. The soil moisture datasets were derived from algorithms developed by the National Snow and Ice Data Center (NSIDC) and jointly developed by the Vrije Universiteit Amsterdam and NASA Goddard Space Flight Center (VUA-NASA). The NSIDC and VUA-NASA products were compared to in situ soil moisture data from nine enhanced coordinated observation stations. The VUANASA dataset presented a strong correlation with top layer in situ soil moisture observations, and the correlation coefficients ranged from 0.34 to 0.73 (p〈0.01). The correlation coefficients decreased as the observed soil layer depth increased. The correlation coefficients between the NSIDC retrievals and the top layer in situ observations were between -0.10 and 0.62 (p〈0.01). Furthermore, VUA-NASA soil moisture variations agreed well with in situ soil moisture dynamics and responded sensitively to precipitation events. In contrast, the NSIDC dataset failed to capture signals of soil moisture dynamics. The analyses demonstrated that the VUA-NASA product was capable of representing soil moisture conditions over northern China.

  8. Estimation of Summer Rainfall over an Arid Area using AMSR-E Measurements:A Case Study in Xinjiang,China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Rainfall estimate in arid region using passive microwave remote sensing techniques has been a complex issue for some time.The main reason for this difficulty is that the high and variable emissivity of land surfaces greatly aggravates the complexity of the signatures from the rain cloud.The Xinjiang area,located in the northwest of China,holds all the typical characteristics of arid climate.A rainfall algorithm has been developed for this region by using the Advanced Microwave Scanning Radiometer for Earth Observing System(AMSR-E) measurements.The algorithm attempts to use all 12 chan-nels on the AMSR-E instrument and a two-step method calibrated over 11 days of hourly rain-gauge data.First,Stepwise Discriminant Analysis(SDA) used to optimally estimate rain pixels based on all 12 channels,although only three channels were found to be necessary.Next,a rain predicator scattering index was used to estimate rain rates.A linear relationship between the rain rates and the scattering index above the threshold of 3.0K was constructed with a simple approximately linear function.The estimated rain rates were compared with the rain-gauge data used to calibrate the method,and a good relationship was found with a root-mean-square error of 2.1mm/h.The numerical calculations and comparisons show that the algorithm works well in the Xinjiang area.

  9. Retrieval Snow Depth by Artificial Neural Network Methodology from Integrated AMSR-E and In-situ Data——A Case Study in Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    CAO Yungang; YANG Xiuchun; ZHU Xiaohua

    2008-01-01

    On the basis of artificial neural network (ANN) model, this paper presents an algorithm for inversing snow depth with use of AMSR-E (Advanced Microwave Scanning Radiometer-Earth Observing System (EOS)) dataset, i.e., brightness temperature at 18.7 and 36.5GHz in Qinghai-Tibet Plateau during the snow season of 2002-2003. In order to overcome the overfitting problem in ANN modeling, this methodology adopts a Bayesian regularization approach. The experiments are performed to compare the results obtained from the ANN-based algorithm with those obtained from other existing algorithms, i.e., Chang algorithm, spectral polarization difference (SPD) algorithm, and tempera-ture gradient (TG) algorithm. The experimental results show that the presented algorithm has the highest accuracy in estimating snow depth. In addition, the effects of the noises in damsels on model fitting can be decreased due to adopt-ing the Bayesian regularization approach.

  10. Antarctic Iceberg Tracking Based on Time Series of Aqua AMSRE Microwave Brightness Temperature Measurements

    Science.gov (United States)

    Blonski, Slawomir; Peterson, Craig

    2006-01-01

    Observations of icebergs are identified as one of the requirements for the GEOSS (Global Earth Observation System of Systems) in the area of reducing loss of life and property from natural and human-induced disasters. However, iceberg observations are not included among targets in the GEOSS 10-Year Implementation Plan, and thus there is an unfulfilled need for iceberg detection and tracking in the near future. Large Antarctic icebergs have been tracked by the National Ice Center and by the academic community using a variety of satellite sensors including both passive and active microwave imagers, such as SSM/I (Special Sensor Microwave/Imager) deployed on the DMSP (Defense Meteorological Satellite Program) spacecraft. Improvements provided in recent years by NASA and non-NASA satellite radars, scatterometers, and radiometers resulted in an increased number of observed icebergs and even prompted a question: Is The Number of Antarctic Icebergs Really Increasing? [D.G. Long, J. Ballantyne, and C. Bertoia, Eos, Transactions of the American Geophysical Union 83 (42): 469 & 474, 15 October 2002]. AMSR-E (Advanced Microwave Scanning Radiometer for the Earth Observing System) represents an improvement over SSM/I, its predecessor. AMSR-E has more measurement channels and higher spatial resolution than SSM/I. For example, the instantaneous field of view of the AMSR-E s 89-GHz channels is 6 km by 4 km versus 16 km by 14 km for SSM/I s comparable 85-GHz channels. AMSR-E, deployed on the Aqua satellite, scans across a 1450-km swath and provides brightness temperature measurements with nearglobal coverage every one or two days. In polar regions, overlapping swaths generate coverage up to multiple times per day and allow for creation of image time series with high temporal resolution. Despite these advantages, only incidental usage of AMSR-E data for iceberg tracking has been reported so far, none in an operational environment. Therefore, an experiment was undertaken in the RPC

  11. A Downscaling Method for Improving the Spatial Resolution of AMSR-E Derived Soil Moisture Product Based on MSG-SEVIRI Data

    Directory of Open Access Journals (Sweden)

    Wei Zhao

    2013-12-01

    Full Text Available Soil moisture is a vital parameter in various land surface processes, and microwave remote sensing is widely used to estimate regional soil moisture. However, the application of the retrieved soil moisture data is restricted by its coarse spatial resolution. To overcome this weakness, many methods were proposed to downscale microwave soil moisture data. The traditional method is the microwave-optical/IR synergistic approach, in which land surface temperature (LST, vegetation index and surface albedo are key parameters. However, due to the uncertainty in absolute LST estimation, this approach is partly dependent on the accuracy of LST estimation. To eliminate the impacts of LST estimation, an improved downscaling method is proposed in this study to downscale Advanced Microwave Scanning Radiometer on the Earth Observing System (AMSR-E Land Parameter Retrieval Model (LPRM soil moisture product with visible and thermal data of Meteosat Second Generation (MSG—Spinning Enhanced Visible and Infrared Imager (SEVIRI. Two temperature temporal variation parameters related to soil moisture, including mid-morning rising rate and daily maximum temperature time, are introduced in the proposed method to replace LST. The proposed method and the traditional method are both applied to the Iberian Peninsula area for July and August 2007. Comparison of the two results shows that the coefficient of determination (R-squared has an average improvement of 0.08 and the root mean square error has a systematic decrease. The downscaled soil moisture by the proposed method was validated by REMEDHUS soil moisture network in the study area, and site specific validation gets poor correlation between the two datasets because of the low spatial representativeness of site measurement for one MSG-SEVIRI pixel. Although the comparisons at 15 km and network scale show an improvement over the site specific comparison, it is found that the downscaling method systematically degrades

  12. Improving Simulated Soil Moisture Fields Through Assimilation of AMSR-E Soil Moisture Retrievals with an Ensemble Kalman Filter and a Mass Conservation Constraint

    Science.gov (United States)

    Li, Bailing; Toll, David; Zhan, Xiwu; Cosgrove, Brian

    2011-01-01

    Model simulated soil moisture fields are often biased due to errors in input parameters and deficiencies in model physics. Satellite derived soil moisture estimates, if retrieved appropriately, represent the spatial mean of soil moisture in a footprint area, and can be used to reduce model bias (at locations near the surface) through data assimilation techniques. While assimilating the retrievals can reduce model bias, it can also destroy the mass balance enforced by the model governing equation because water is removed from or added to the soil by the assimilation algorithm. In addition, studies have shown that assimilation of surface observations can adversely impact soil moisture estimates in the lower soil layers due to imperfect model physics, even though the bias near the surface is decreased. In this study, an ensemble Kalman filter (EnKF) with a mass conservation updating scheme was developed to assimilate the actual value of Advanced Microwave Scanning Radiometer (AMSR-E) soil moisture retrievals to improve the mean of simulated soil moisture fields by the Noah land surface model. Assimilation results using the conventional and the mass conservation updating scheme in the Little Washita watershed of Oklahoma showed that, while both updating schemes reduced the bias in the shallow root zone, the mass conservation scheme provided better estimates in the deeper profile. The mass conservation scheme also yielded physically consistent estimates of fluxes and maintained the water budget. Impacts of model physics on the assimilation results are discussed.

  13. Use of high frequency radiometer and altimeter on board AMSU-B, AMSR-E and Altika/SARAL for observations of the Antarctic ice sheet surface.

    Science.gov (United States)

    Adodo, Fifi; Picard, Ghislain; Remy, Frederique

    2016-04-01

    Snow surface properties quickly evolved according to local weather conditions, therefore are climate change indicator. These snow surface properties such as grain size, density, accumulation rate etc... are very important for evaluation and monitoring of the impact of global warming on the polar ice sheet. In order to retrieve these snowpack properties, we explore the high frequency microwave radiometer variable( Brightness Temperature (Tb)) on the Antarctic ice sheet on-board AMSU-B , AMSR-E in combination with the ALTIKA altimeter (37GHz) waveform parameters (Backscatter coefficient, Trailing edge Slope(TeS) and Leading edge Width(LeW)). We compare the radiometer brightness temperature to calculations with the DMRT- ML radiative transfer model which simulates brightness temperature in vertical and horizontal polarizations. With some assumptions, this combination allows a good retrieval of snowpack properties. We showed positive trend of the grains size on the Antarctic plateau especially at Dome C during the two last decades. This work will provide a higher accuracy of the estimation of snowpack surfaces properties and contribute to monitoring the ice sheet surface mass balance, well constraining of meteorological and glaciological models.

  14. SST, Aqua AMSR-E, 0.25 degrees, Global, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA OceanWatch provides sea surface temperature (SST) products derived from microwave sensors, which can measure ocean temperatures even in the presence of clouds....

  15. Satellite Remote Sensing of Pan-arctic Vegetation Productivity, Soil Respiration and net CO2 Exchange Using MODIS and AMSR-E Data

    Science.gov (United States)

    Nirala, M. L.; Heinsch, F. A.; Kimball, J. S.; Zhao, M.; Running, S.; Oechel, W.; McDonald, K.; Njoku, E.

    2005-05-01

    We have developed an approach for regional assessment and monitoring of land-atmosphere carbon dioxide (CO2) exchange, soil heterotrophic respiration (Rh) and vegetation productivity for arctic tundra using global satellite remote sensing at optical and microwave wavelengths. We use C- and X-band brightness temperatures from AMSR-E to extract surface wetness and temperature, and MODIS data to derive land cover, Leaf Area Index (LAI) and Net Primary Production (NPP) information. Calibration and validation activities involve comparisons between satellite remote sensing and tundra CO2 eddy flux tower and biophysical measurement networks and hydro-ecological process model simulations. We analyze spatial and temporal anomalies and environmental drivers of land-atmosphere net CO2 exchange at weekly and annual time steps. Surface soil moisture status and temperature as detected from satellite remote sensing observations are found to be major drivers spatial and temporal patterns of tundra net CO2 exchange and photosynthetic and respiration processes. We also find that satellite microwave measurements are capable of capturing seasonal variations and regional patterns in tundra soil heterotrophic respiration and CO2 exchange, while our ability to extract spatial patterns at the scale of surface heterogeneity is limited by the coarse spatial scale of the satellite remote sensing footprint. Our results also indicate that carbon cycle response to climate change is non-linear and strongly coupled to arctic surface hydrology. This work was performed at The University of Montana and Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

  16. Effect of AMSR-E data interference on the retrieval of land surface parameters%AMSR-E观测资料干扰对反演地表参数的影响

    Institute of Scientific and Technical Information of China (English)

    张思勃; 官莉

    2015-01-01

    针对星载微波成像仪低频窗区通道观测数据中存在大范围无线电频率干扰(简称RFI)的情况,以微波扫描辐射计(AMSR-E)为例,首先用改进的主成分分析方法对RFI进行识别;进而探讨RFI存在对反演地表参数的影响.然后,利用经过线性拟合RFI订正后的AMSR-E观测资料,采用一维变分1D-Var方法进行地表参数反演,通过对美国地区陆地RFI订正前、后地表反演产品(地表温度及降水率)的比较,发现RFI干扰使得受影响区域反演的地表温度及降水率异常偏高,存在较大误差.因此,在使用星载微波成像仪低频窗区通道观测进行地表参数反演和资料同化前必须进行有效地RFI识别和订正,改进的主成分分析识别方法和线性拟合的RFI订正算法对陆地上观测是有效的.

  17. 基于 AMSR-E 遥感数据应用强度比参数确定多年冰的方法探讨%USE OF CONTRAST RATIO TO DETECT MULTI-YEAR ICE USING AMSR-E PASSIVE MICROWAVE DATA

    Institute of Scientific and Technical Information of China (English)

    张树刚; 郭发东; 张继明; 刘雷; 白雪娇

    2016-01-01

    研究发现,AMSR-E的垂直极化的18.7 GHz ( V18.7)和36.5 GHz ( V36.5)的亮温比值在一年冰覆盖区域主要是相应频段的海冰微波发射率之比,而在多年冰覆盖区域受海冰微波发射率和海冰温度共同影响,并且海冰年龄越大亮温比值也越大。应用强度比参数可以比较好地确定冬季一年冰与多年冰之间的阈值,其中,在该阈值处,强度比梯度达到最大。该阈值呈现明显的季节性变化规律,在冬季阈值比较稳定,而在夏季受海水的影响变化范围比较大。应用强度比方法确定的多年冰范围,与NASA Team2( NT2)方法相比在大西洋扇区差异非常小;而在太平洋扇区出现比较大的差异。对比发现强度比法确定的多年冰范围一般大于NT2法。%This study found that the ratio of vertically polarized brightness temperature of AMSR -E passive microwave data at 18.7 and 36.5 is the ratio of sea ice microwave emissivity for first-year ice.However, for multi-year ice, this ra-tio is also affected by sea ice temperature .Furthermore , the ratio for older ice is larger than for younger ice .The contrast ratio is a suitable parameter with which to ascertain the threshold between first-year and multi-year ice be-cause the maximum gradient of the contrast ratio appears at the threshold .This threshold varies seasonally;it is rel-atively steady during winter but changes considerably during summer because of the influence of meltwater .Little difference was found in the multi-year ice coverage of the Arctic section of the Atlantic Ocean when ascertained by the contrast ratio and NASA Team2 (NT2) algorithm;however, large differences were found in the Arctic section of the Pacific Ocean.In comparison to the NT2, the coverage of multi-year ice is commonly found to be larger when ascertained using the contrast ratio .

  18. Global Land Surface Temperature Retrieval with AMSR-E Brightness Temperature and MODIS Land Cover Type Products%AMSR-E亮温数据与MODIS陆表分类产品结合反演全球陆表温度

    Institute of Scientific and Technical Information of China (English)

    武胜利; 杨虎

    2007-01-01

    AMSR-E被动微波传感器获取的亮温数据与MODIS陆表分类产品(MOD12)相结合,将全球陆表分为16类,并假设每种类型的地表在各个被动微波通道具有较一致的发射率,在此基础上针对每种陆表类型分别建立了陆表温度反演算法.在算法的建立过程中,为了避免混合像元以及冻土、积雪发射率不确定性带来的影响,仅对单一地表类型占90%以上以及MODIS陆表温度产品高于273K的被动微波像元进行回归.同时,考虑到降雨对回归结果的影响,在数据选择中加入了降雨判识,在被动微波亮温数据中除去了降雨像元.利用上述算法,用2004年1~10月的全球部分地区AMSR-E数据在MODIS陆表分类产品的基础上对每种地表类型分别进行了陆表温度反演,并与MODIS陆表温度产品进行对比,结果显示相关性较好,均方根误差为2~4 K.

  19. A Downscaling Method for AMSR-E Soil Moisture Using MODIS Derived Dryness Index%基于MODIS和AMSR-E遥感数据的土壤水分降尺度研究

    Institute of Scientific and Technical Information of China (English)

    曹永攀; 晋锐; 韩旭军; 李新

    2011-01-01

    微波传感器获得的土壤水分产品空间分辨率一般都很粗,而流域尺度上的研究需要中高分辨率的土壤水分数据。用MODIS逐日地表温度产品MOD11A1和逐日地表反射率产品MOD09GA构建温度—植被指数特征空间,并计算得到TVDI(Temperature Vegetation Dryness Index)指数,它与土壤水分呈负相关关系,能够反映土壤水分的空间分布模式,但并不是真实的土壤水分值。在AMSR-E像元尺度上求得TVDI与土壤水分的负相关系数,进而对VUA AMSR-E土壤水分产品进行降尺度计算得到0.01°分辨率的真实土壤水分值。经NAFE06(The National Airborne Field Experiment 2006)试验地面采样数据验证,降尺度后的土壤水分均方根误差平均值为6.1%。%The near-surface soil moisture data retrieved from passive microwave sensors has the coarse resolution,while the study in a river basin need soil moisture data in high spatial resolution.LST-NDVI space is generated by MODIS Land Surface Temperature Products(MOD11A1) and MODIS Surface Reflectance Products(MOD09GA) and Temperature Vegetation Dryness Index is calculated based on that.The index indicate spatial pattern of soil moisture and which is linear regressions with soil moisture.We calculate the linear regression coefficients between TVDI and near-surface soil moisture at the passive microwave scale,and then calculate soil moisture data at MODIS scale.The root mean square error between 0.01 resolution and ground-measured soil moisture collected during the National Airborne Field Experiment 2006 is 6.1%.

  20. Long term observation of soil moisture by the in situ stations and AMSR/AMSR2 a 1.1º by 1.1º study area on the Mongolian Plateau since 2001

    Science.gov (United States)

    Kaihotsu, I.; Asanuma, J.; Aida, K.; Fujii, H.; Oyunbaatar, D.; Koike, T.

    2015-12-01

    Soil moisture behavior has a strong influence on water cycle (especially, interaction between soil and atmosphere) and surface natural environments in semi-arid and arid areas with highly variable rainfall. Recently, as the Mongolian Plateau has been affected by global warning, it has been facing several times severe droughts. So, it is very important to measure continuously and precisely the surface soil moisture. We have been successfully carrying out the in situ soil moisture and meteorological observations using some automatic stations (from 13 to 16 stations) in a 1.1º by 1.1º flat surface land (study area) covered with pasture/shrubs, and a daily large-scale soil moisture observation on the Mongolian Plateau by AMSR-E (Advanced Microwave Scanning Radiometer-EOS) of AQUA and AMSR2 (Advanced Microwave Scanning Radiometer 2) of GCOM-W1 (Global Change Observation Mission-Water 1) since 2001 with making a validation of the AMSR-E/AMSR2 soil moisture products in every year. As a result, we have obtained a few new findings about soil moisture dynamics in the study area. Concretely, there was a decreasing trend of the surface soil moisture in the study area during the period from 2001 to 2008 with the drought development and inversely it started to increase slightly in 2009 with the increase of rainfall in summer. The ratio of evapotranspiration to rainfall from April to September was estimated to be more than about 95 %, and the rainfall condition in summer controlled the amount of annual precipitation and the wet condition on the soil surface. We also knew that AMSR-E/AMSR2 can continuously and successfully conduct a long term monitoring observation of the surface soil moisture on the Mongolian Plateau with the high measurement accuracy between 4 and 5 % on a large scale. This fact suggests that AMSR-E/AMSR2 soil moisture observation is useful for studies of water cycle over large areas of grass. Keywords: soil moisture, rainfall, in situ observation, AMSR-E/AMSR

  1. Soil Moisture derivation from the multi-frequency sensor AMSR-2

    Science.gov (United States)

    Parinussa, Robert; de Nijs, Anne; de Jeu, Richard; Holmes, Thomas; Dorigo, Wouter; Wanders, Niko; Schellekens, Jaap

    2015-04-01

    We present a method to derive soil moisture from the multi-frequency sensor Advanced Microwave Scanning Radiometer 2 (AMSR-2). Its predecessor, the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E), has already provided Earth scientists with a consistent and continuous global soil moisture dataset. However, the AMSR-2 sensor has one big advantage in relation to the AMSR-E sensor; is has an additional channel in the C-band frequency (7.3 GHz). This channel creates the opportunity to have a better screening for Radio Frequency Interference (RFI) and could eventually lead to improved soil moisture retrievals. The soil moisture retrievals from AMSR-2 we present here use the Land Parameter Retrieval Model (LPRM) in combination with a new radio frequency interference masking method. We used observations of the multi-frequency microwave radiometer onboard the Tropical Rainfall Measuring Mission (TRMM) satellite to intercalibrate the brightness temperatures in order to improve consistency between AMSR-E and AMSR-2. Several scenarios to accomplish synergy between the AMSR-E and AMSR-2 soil moisture products were evaluated. A global comparison of soil moisture retrievals against ERA Interim re-analysis soil moisture demonstrates the need for an intercalibration procedure. Several different scenarios based on filtering were tested and the impact on the soil moisture retrievals was evaluated against two independent reference soil moisture datasets (reanalysis and in situ soil moisture) that cover the observation periods of the AMSR-E and AMSR-2 sensors. Results show a high degree of consistency between both satellite products and two independent reference products for the soil moisture products. In addition, the added value of an additional frequency for RFI detection is demonstrated within this study with a reduction of the total contaminated pixels in the 6.9 GHz of 66% for horizontal observations and even 85% for vertical observations when 7.3 and 10

  2. Status of calibration and data evaluation of AMSR on board ADEOS-II

    Science.gov (United States)

    Imaoka, Keiji; Fujimoto, Yasuhiro; Kachi, Misako; Takeshima, Toshiaki; Igarashi, Tamotsu; Kawanishi, Toneo; Shibata, Akira

    2004-02-01

    The Advanced Microwave Scanning Radiometer (AMSR) is the multi-frequency, passive microwave radiometer on board the Advanced Earth Observing Satellite-II (ADEOS-II), currently called Midori-II. The instrument has eight-frequency channels with dual polarization (except 50-GHz band) covering frequencies between 6.925 and 89.0 GHz. Measurement of 50-GHz channels is the first attempt by this kind of conically scanning microwave radiometers. Basic concept of the instrument including hardware configuration and calibration method is almost the same as that of ASMR for EOS (AMSR-E), the modified version of AMSR. Its swath width of 1,600 km is wider than that of AMSR-E. In parallel with the calibration and data evaluation of AMSR-E instrument, almost identical calibration activities have been made for AMSR instrument. After finished the initial checkout phase, the instrument has been continuously obtaining the data in global basis. Time series of radiometer sensitivities and automatic gain control telemetry indicate the stable instrument performance. For the radiometric calibration, we are now trying to apply the same procedure that is being used for AMSR-E. This paper provides an overview of the instrument characteristics, instrument status, and preliminary results of calibration and data evaluation activities.

  3. A comparison between two algorithms for the retrieval of soil moisture using AMSR-E data

    Science.gov (United States)

    A comparison between two algorithms for estimating soil moisture with microwave satellite data was carried out by using the datasets collected on the four Agricultural Research Service (ARS) watershed sites in the US from 2002 to 2009. These sites collectively represent a wide range of ground condit...

  4. A COMPARISON BETWEEN TWO ALGORITHMS FOR THE RETRIEVAL OF SOIL MOISTURE USING AMSR-E DATA

    OpenAIRE

    Simonetta ePaloscia; Emanuele eSanti; Simone ePettinato; Iliana eMladenova; Tom eJackson; Michael eCosh

    2015-01-01

    A comparison between two algorithms for estimating soil moisture with microwave satellite data was carried out by using the datasets collected on the four Agricultural Research Service (ARS) watershed sites in the US from 2002 to 2009. These sites collectively represent a wide range of ground conditions and precipitation regimes (from natural to agricultural surfaces and from desert to humid regions) and provide long-term in-situ data. One of the algorithms is the artificial neural network-ba...

  5. A comparison between two algorithms for the retrieval of soil moisture using AMSR-E data

    OpenAIRE

    Paloscia, Simonetta; santi, emanuele; Pettinato, Simone; Mladenova, Iliana; Jackson, Thomas; Bindlish, Rajat; Cosh, Michael

    2015-01-01

    A comparison between two algorithms for estimating soil moisture with microwave satellite data was carried out by using the datasets collected on the four Agricultural Research Service (ARS) watershed sites in the US from 2002 to 2009. These sites collectively represent a wide range of ground conditions and precipitation regimes (from natural to agricultural surfaces and from desert to humid regions) and provide long-term in-situ data. One of the algorithms is the artificial neural network-ba...

  6. SMEX03 AMSR-E Daily Gridded Soil Moisture and Brightness Temperatures, Oklahoma

    Data.gov (United States)

    National Aeronautics and Space Administration — Notice to Data Users: The documentation for this data set was provided solely by the Principal Investigator(s) and was not further developed, thoroughly reviewed,...

  7. SMEX03 AMSR-E Daily Gridded Soil Moisture and Brightness Temperatures, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — Notice to Data Users: The documentation for this data set was provided solely by the Principal Investigator(s) and was not further developed, thoroughly reviewed,...

  8. Retrievals of All-Weather Daily Air Temperature Using MODIS and AMSR-E Data

    OpenAIRE

    Keunchang Jang; Sinkyu Kang; John S. Kimball; Suk Young Hong

    2014-01-01

    Satellite optical-infrared remote sensing from the Moderate Resolution Imaging Spectroradiometer (MODIS) provides effective air temperature (Ta) retrieval at a spatial resolution of 5 km. However, frequent cloud cover can result in substantial signal loss and remote sensing retrieval error in MODIS Ta. We presented a simple pixel-wise empirical regression method combining synergistic information from MODIS Ta and 37 GHz frequency brightness temperature (Tb) retrievals from the Advanced Microw...

  9. Standard Dataset of Brightness Temperature Resampled by Antenna Pattern Matching for Microwave Radiometer AMSR2 on GCOM-W1 Satellite

    Science.gov (United States)

    Maeda, Takashi; Imaoka, Keiji

    2014-05-01

    The operation of the Advanced Microwave Scanning Radiometer for Earth-Observation System (AMSR-E) loaded on Aqua satellite stopped in October, 2011 after more than 9-years observation. But after that, the successor of AMSR-E (AMSR2) was developed and loaded on GCOM-W1 (Global Change Observation Mission 1st - Water) satellite. GCOM-W1 satellite was successfully launched in May, 2012. AMSR2 is a microwave radiometer almost similar to AMSR-E, but some important improvements are made (i.e., expansion of its main reflector's size, addition of 7.3-GHz channel to detect radio frequency interferences at 6.9 GHz). GCOM-W1 satellite is deployed into a sun-synchronous sub-recurrent orbit, and AMSR2 observes microwave powers emitted from anywhere on the Earth almost twice a day, daytime in an ascending track and nighttime in a descending track. When we use a satellite-borne microwave radiometer data that have a main reflector shared by plural feed horns, there is an inevitable problem, the differences of footprints' sizes among frequencies. In case of AMSR2, the smallest footprint's size of 89 GHz (3 × 5 km2) has just one percent of the broadest one of 6.9 GHz (35 × 62 km2). Under the circumstance, when brightness temperatures (Tb values) of plural frequencies are obtained from the same geolocation, it is difficult to compare them one another because their observation areas are absolutely different. The concept to solve this problem is simple: actually, after a satellite-borne microwave radiometer observed on the Earth's surface, footprints which give brightness temperatures of each frequency densely distribute on it with overlaps at several-kilometer intervals (i.e., 5 km as for 89 GHz and 10 km as for other frequencies in AMSR2). The footprint is an antenna pattern projected to the Earth's surface. The antenna pattern's shape is generally like a 2-dimensional Gaussian distribution. The center of the antenna pattern has strong sensitivity, and its circumjacent part has weak

  10. Estimation of Land Surface Temperature from GCOM-W1 AMSR2 Data over the Chinese Landmass

    Science.gov (United States)

    Zhou, Ji; Dai, Fengnan; Zhang, Xiaodong

    2016-04-01

    method is applied to AMSR2 data, it has good ability to extend to other satellite PW sensors, such as the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) on board the Aqua satellite and the Special Sensor Microwave/Imager (SSM/I) on board the Defense Meteorological Satellite Program (DMSP) satellite. It would be beneficial in providing LST to applications at continental and global scales.

  11. Satellite Sampling and Retrieval Errors in Regional Monthly Rain Estimates from TMI AMSR-E, SSM/I, AMSU-B and the TRMM PR

    Science.gov (United States)

    Fisher, Brad; Wolff, David B.

    2010-01-01

    Passive and active microwave rain sensors onboard earth-orbiting satellites estimate monthly rainfall from the instantaneous rain statistics collected during satellite overpasses. It is well known that climate-scale rain estimates from meteorological satellites incur sampling errors resulting from the process of discrete temporal sampling and statistical averaging. Sampling and retrieval errors ultimately become entangled in the estimation of the mean monthly rain rate. The sampling component of the error budget effectively introduces statistical noise into climate-scale rain estimates that obscure the error component associated with the instantaneous rain retrieval. Estimating the accuracy of the retrievals on monthly scales therefore necessitates a decomposition of the total error budget into sampling and retrieval error quantities. This paper presents results from a statistical evaluation of the sampling and retrieval errors for five different space-borne rain sensors on board nine orbiting satellites. Using an error decomposition methodology developed by one of the authors, sampling and retrieval errors were estimated at 0.25 resolution within 150 km of ground-based weather radars located at Kwajalein, Marshall Islands and Melbourne, Florida. Error and bias statistics were calculated according to the land, ocean and coast classifications of the surface terrain mask developed for the Goddard Profiling (GPROF) rain algorithm. Variations in the comparative error statistics are attributed to various factors related to differences in the swath geometry of each rain sensor, the orbital and instrument characteristics of the satellite and the regional climatology. The most significant result from this study found that each of the satellites incurred negative longterm oceanic retrieval biases of 10 to 30%.

  12. Sea Ice Brightness Temperature as a Function of Ice Thickness: Computed curves for AMSR-E and SMOS (frequencies from 1.4 to 89 GHz)

    CERN Document Server

    Mills, Peter

    2012-01-01

    The relationship between sea ice thickness and microwave brightness temperature is explored. Parameterized ice profiles are fed to a radiative-transfer-based sea ice emissivity model (Microwave Emmission of Layered Snowpack, MEMLS). Complex permittivities, required as input for the simulation, are determined using a semi-empirical mixture model. Since the thickness-radiance relation is not fixed but can vary significantly depending upon past and current weather conditions, we determine a range of brightness temperature values for each thickness. This is done using a bootstrap model in which the salinities are varied based on variances supplied with the thickness-salinity curve and the complex permittivities are varied based on variance supplied by the mixture model. The results suggest that scattering is one of the most important parameters determining sea ice brightness temperature, especially for new and forming ice. Further work must be done to accurately model both scattering and complex permittivities in...

  13. Remote Sensing of Soil Moisture based on Dynamic Vegetation Scattering Properties for AMSR sensors

    Science.gov (United States)

    Du, J.; Kimball, J. S.; Jones, L. A.

    2015-12-01

    Accurate mapping of soil moisture and its spatial-temporal variations are of great significance to scientific studies on global water, energy and carbon cycles as well as operational applications including flood and drought monitoring, water resources management and crop yield forecasts. An approach for deriving volumetric soil moisture using satellite passive microwave radiometry from the Advanced Microwave Scanning Radiometers AMSR-E and AMSR2 was developed in this study. The algorithm adopts a weighted averaging strategy for soil moisture estimation based on a dynamic selection of empirically determined vegetation single-scatter albedo values. The resulting soil moisture retrievals demonstrate more realistic global patterns and seasonal dynamics relative to the baseline University of Montana (UMT) soil moisture product. Quantitative analysis of the new approach against in situ soil moisture measurements over four global study regions also indicates significant improvement over the baseline algorithm, with coefficients of determination (R2) between the retrievals and in-situ measurements increasing by approximately 16.9% and 41.5% respectively; and bias-corrected RMSEs decreasing by about 25.0% and 38.2% for respective ascending and descending orbital data records. Initial comparisons between soil moisture retrievals from AMSR2 and SMAP indicate coherent global and seasonal patterns.

  14. Validation of microwave vegetation indices using field experiment data sets

    Science.gov (United States)

    A recent study established the theoretical basis for a new type of index based on passive microwave vegetation indices (MVIs). The approach was then calibrated for use with data from the Advanced Microwave Scanning Radiometer (AMSR-E) on the Aqua satellite under the assumption that there is no signi...

  15. Assimilation of coarse-scale satellite soil moisture observations into a fine-scale hydrologic model

    Science.gov (United States)

    It has been demonstrated that passive microwave observations from space are capable of mapping surface soil moisture over the globe. Currently, the Advanced Microwave Scanning Radiometer (AMSR-E) onboard NASA’s Aqua satellite is providing moisture content in the top 1~2 cm of the soil column, and f...

  16. The impact of horizontal heterogeneities, cloud fraction, and liquid water path on warm cloud effective radii from CERES-like Aqua MODIS retrievals

    Directory of Open Access Journals (Sweden)

    D. Painemal

    2013-10-01

    Full Text Available The impact of horizontal heterogeneities, liquid water path (LWP from AMSR-E, and cloud fraction (CF on MODIS cloud effective radius (re, retrieved from the 2.1 μm (re2.1 and 3.8 μm (re3.8 channels, is investigated for warm clouds over the southeast Pacific. Values of re retrieved using the CERES algorithms are averaged at the CERES footprint resolution (∼20 km, while heterogeneities (Hσ are calculated as the ratio between the standard deviation and mean 0.64 μm reflectance. The value of re2.1 strongly depends on CF, with magnitudes up to 5 μm larger than those for overcast scenes, whereas re3.8 remains insensitive to CF. For cloudy scenes, both re2.1 and re3.8 increase with Hσ for any given AMSR-E LWP, but re2.1 changes more than for re3.8. Additionally, re3.8–re2.1 differences are positive (Hσ 45 gm−2, and negative (up to −4 μm for larger Hσ. While re3.8–re2.1 differences in homogeneous scenes are qualitatively consistent with in situ microphysical observations over the region of study, negative differences – particularly evinced in mean regional maps – are more likely to reflect the dominant bias associated with cloud heterogeneities rather than information about the cloud vertical structure. The consequences for MODIS LWP are also discussed.

  17. New methods for reducing cloud obscuration based on combination products of MODIS and AMSR2

    Science.gov (United States)

    Li, Muyi; Pan, Yaozhong; Zhu, Xiufang; Yin, Heyang

    2016-04-01

    As one of the main sources for water availability in semi-arid mountain regions, snow melt provides runoff and water supply for the downstream population and is of great importance for both human and environmental systems. For this reason, snow data such as snow cover (SCA) and snow depth (SD) is especially important. Snow cover has been mapped using many remote sensors in the visible, near-infrared, thermal, and microwave wavelengths. Since 1966, optical remote sensors such as AVHRR, Landsat and MODIS have obtained critically important data for observing the earth's snow cover. The Moderate Resolution Imaging Spectroradiometer (MODIS) employed by Terra and Aqua satellites provides spatially snow covered data with 500 m and daily temporal resolution. However the utility of the MODIS snow-cover products is limited by cloud cover which causes gaps in the daily snow-cover map products. In this paper, we developed a new method in order to reduce cloud obscuration. This method includes four parts: A) Combining various MODIS Terra and Aqua products; B) Temporal and spatial filtering; C) Zonal snowline approach and D) Combining the product deriving from the above three parts and the AMSR2 passive microwave snow depth product (with a spatial resolution of 10 km). In part D, the consistency of two different data (optical remote sensing data with spatial resolution of 500 m and passive microwave remote sensing data with a spatial resolution of 10 km) was evaluated. This study was carried out for Qinghai Province located in northwestern part of China during 1st, October, 2013 to 31st, March, 2015. In order to evaluate the performance of the proposed methodology, 14 MODIS snow cover product tiles (with cloud coverage less than 10%) were selected as possible "ground truth" data and cloud mask was generated for each tile randomly. The results show successful performances arising from the methods applied, which resulted in all cloud coverage being removed. The overall accuracy of

  18. An introduction to factor analysis for radio frequency interference detection on satellite observations

    OpenAIRE

    Islam, Tanvir; Srivastava, Prashant K; Dai, Qiang; Gupta, Manika; Zhuo, Lu

    2015-01-01

    A novel radio frequency interference (RFI) detection method is introduced for satellite-borne passive microwave radiometer observations. This method is based on factor analysis, in which variability among observed and correlated variables is described in terms of factors. In the present study, this method is applied to the Tropical Rainfall Measuring Mission (TRMM)/TRMM Microwave Imager (TMI) and Aqua/Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E) satellite measureme...

  19. AquaBuOY

    DEFF Research Database (Denmark)

    Weinstein, Alla; Fredrikson, Göran; Claeson, Lennart;

    2003-01-01

    This paper describes development of the mathematical model simulating ocean performance of an offshore wave energy point absorber device-AquaBuOY. The AquaBuOY is the next generation of the technology, based on the IPS point absorber system and the hose pump, both of Sweden. AquaEnergy Group Ltd......., USA, is developing the system in cooperation with RAMBOLL, Denmark. In March 2003 the Danish Energy Authority awarded a grant for a design study that includes development of the numerical model for the AquaBuOY operation, experimental testing and design optimisation. The scale model tests...... results from the model tests on mooring forces under survival conditions will be presented during the conference in conjunction with different footprint configurations and different mooring systems. Finally the performance data based on theoretical and experimental results will be presented for the AquaBu...

  20. Sea Ice Surface Temperature Product from the Moderate Resolution Imaging Spectroradiometer (MODIS)

    Science.gov (United States)

    Hall, Dorothy K.; Key, Jeffrey R.; Casey, Kimberly A.; Riggs, George A.; Cavalieri, Donald J.

    2003-01-01

    Global sea ice products are produced from the Earth Observing System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS) on board both the Terra and Aqua satellites. Daily sea ice extent and ice-surface temperature (IST) products are available at 1- and 4-km resolution. Validation activities have been undertaken to assess the accuracy of the MODIS IST product at the South Pole station in Antarctica and in the Arctic Ocean using near-surface air-temperature data from a meteorological station and drifting buoys. Results from the study areas show that under clear skies, the MODIS ISTs are very close to those of the near-surface air temperatures with a bias of -1.1 and -1.2 K, and an uncertainty of 1.6 and 1.7 K, respectively. It is shown that the uncertainties would be reduced if the actual temperature of the ice surface were reported instead of the near-surface air temperature. It is not possible to get an accurate IST from MODIS in the presence of even very thin clouds or fog, however using both the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) and the MODIS on the Aqua satellite, it may be possible to develop a relationship between MODIS-derived IST and ice temperature derived from the AMSR-E. Since the AMSR-E measurements are generally unaffected by cloud cover, they may be used to complement the MODIS IST measurements.

  1. GCOM-W1 AMSR2 research products

    Science.gov (United States)

    Maeda, Takashi; Seki, Mieko; Sekiya, Keiji; Kachi, Misako

    2016-04-01

    Japan Aerospace Exploration Agency (JAXA) has operated the Advanced Microwave Scanning Radiometer 2 (AMSR2) onboard the GCOM-W1 satellite lauched in May 2012. In this mission, 8 geophysical values (water vapor, cloud liquid water, precipitation, sea surface temperature, sea surface wind speed, sea ice concentration, snow depth, and soil moisture) were defined as the standard products, and these are released to the public since May 2013. On the other hand, several research products (e.g., land surface temperature, vegetation water content, sea ice motion vector, thin sea ice detection, and high-resolution sea ice concentration) as a candidate of a future standard product were officially defined in March 2015. Based on it, we started to implement algorithms to create the research products from the AMSR2 data, and obtained the initial validation results. In this paper, we present the current status of GCOM-W1 AMSR2 research products.

  2. 78 FR 61446 - Fourteenth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S

    Science.gov (United States)

    2013-10-03

    ... Federal Aviation Administration Fourteenth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S AGENCY... RTCA Special Committee 222, Inmarsat AMS(R)S. SUMMARY: The FAA is issuing this notice to advise the public of the fourteenth meeting of the RTCA Special Committee 222, Inmarsat AMS(R)S DATES: The...

  3. 78 FR 8684 - Twelfth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S

    Science.gov (United States)

    2013-02-06

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S AGENCY... RTCA Special Committee 222, Inmarsat AMS(R)S. SUMMARY: The FAA is issuing this notice to advise the public of the twelfth meeting of the RTCA Special Committee 222, Inmarsat AMS(R)S. DATES: The...

  4. Aqua Logistics Opens Office in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Aqua Logistics forays into the region with its subsidiary Aqua Logistics China Ltd. Aqua Logistics Ltd.,India-based full scope multi-national service provider,opened its subsidiary-Aqua Logistics China Ltd.(ALCL) in Beijing on October 23.

  5. Active-Layer Soil Moisture Content Regional Variations in Alaska and Russia by Ground-Based and Satellite-Based Methods, 2002 Through 2014

    Science.gov (United States)

    Muskett, Reginald; Romanovsky, Vladimir; Cable, William; Kholodov, Alexander

    2015-04-01

    Soil moisture is a vital physical parameter of the active-layer in permafrost environments, and associated biological and geophysical processes operative at the microscopic to hemispheric spatial scales and at hourly to multidecadal time scales. While in-situ measurements can give the highest quality of information on a site-specific basis, the vast permafrost terrains of North America and Eurasia require space-based techniques for assessments of cause and effect and long-term changes and impacts from the changes of permafrost and the active-layer. Satellite-based 6.925 and 10.65 GHz sensor algorithmic retrievals of soil moisture by Advanced Microwave Scanning Radiometer - Earth Observation System (AMSR-E) onboard NASA-Aqua and follow-on AMSR2 onboard JAXA-Global Change Observation Mission - Water-1 are ongoing since July 2002. Accurate land-surface temperature and vegetation parameters are critical to the success of passive microwave algorithmic retrieval schemes. Strategically located soil moisture measurements are needed for spatial and temporal co-location evaluation and validation of the space-based algorithmic estimates. We compare on a daily basis ground-based (subsurface-probe) 50- and 70-MHz radio-frequency soil moisture measurements with NASA- and JAXA-algorithmic retrieval passive microwave retrievals. We find improvements in performance of the JAXA-algorithm (AMSR-E reprocessed and AMSR2 ongoing) relative to the earlier NASA-algorithm version. In the boreal forest regions accurate land-surface temperatures and vegetation parameters are still needed for algorithmic retrieval success. Over the period of AMSR-E retrievals we find evidence of at the high northern latitudes of growing terrestrial radio-frequency interference in the 10.65 GHz channel soil moisture content. This is an important error source for satellite-based active and passive microwave remote sensing soil moisture retrievals in Arctic regions that must be addressed. Ref: International

  6. NASA 3D Models: Aqua

    Data.gov (United States)

    National Aeronautics and Space Administration — Aqua, Latin for water, is a NASA Earth Science satellite mission named for the large amount of information that the mission is collecting about the Earth's water...

  7. NASA 3D Models: Aqua

    Data.gov (United States)

    National Aeronautics and Space Administration — Aqua carries six state-of-the-art instruments to observe the Earth's oceans, atmosphere, land, ice and snow covers, and vegetation, providing high measurement...

  8. GHRSST Level 4 RTO Aqua MODIS-AMSRE Night North America Regional Blended Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the JPL Physical...

  9. GHRSST Level 4 RTO Aqua MODIS-AMSRE Day North America Regional Blended Sea Surface Temperature Analysis (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Group for High Resolution Sea Surface Temperature (GHRSST) Level 4 sea surface temperature analysis produced daily on an operational basis at the JPL Physical...

  10. Land surface phenologies and seasonalities using earthlight: A comparison between tropical and temperate croplands

    Science.gov (United States)

    Alemu, W. G.; Henebry, G. M.

    2012-12-01

    Phenology and seasonality are complementary aspects of ecosystem functioning: phenology deals with timing of biotic phenomena; whereas, seasonality concerns temporal patterns of abiotic variables. In this study, we assessed the land surface phenologies and seasonalities in tropical croplands of northwest Ethiopia around Lake Tana and in temperate croplands in the Volga River basin of southeastern European Russia using enhanced land parameters derived from the AMSR-E passive microwave radiometer on the NASA Aqua satellite during 2003-2010. AMSR-E sensed microwave radiation emitted by the atmosphere and land surface at multiple frequencies. Data were acquired at both daytime (~1330) and nighttime (~0130) overpasses. The spatial resolution of the dataset is 25 km. We used the following AMSR-E land surface parameters: air temperature (ta), volumetric soil moisture (mv), fractional cover of open water on land (fw), and vegetation canopy microwave transmittance in three different frequencies (tc06, tc10, and tc18). A 15-day retrospective moving average filter was applied to each parameter time series to minimize data gaps due to orbit and swath width. Growing degree-days (GDDs) were calculated using the daytime and nighttime ta values with a base of 273.15 K and then accumulated (AGDD) with an annual restart each winter solstice. The AMSR-E parameters as a function of AGDD followed seasonal temperature patterns in Russia but seasonal rainfall patterns in Ethiopia. . The behavior of GDD as a function of AGDD displayed strong seasonality with quadratic shape in the Russian croplands, in contrast to a weak seasonality in the Ethiopian croplands. The behavior of canopy transmittance (VOD; vegetation optical depth) as a function of AGDD exhibits seasonalities and display polynomial shape graphs in space and time. During the growing season VODs rapidly ascended to a unimodal peak value and decline gradually. There were sharper decreases in VOD toward the end of the growing

  11. Irrigation modeling with AquaCrop

    Science.gov (United States)

    AquaCrop is a crop water productivity model developed by the Land and Water Division of UN-FAO. It simulates yield response to water of herbaceous crops, and is suited to address conditions where water is a key limiting factor in crop production. AquaCrop attempts to balance accuracy, simplicity, an...

  12. Multi-Sensor Imaging and Space-Ground Cross-Validation for 2010 Flood along Indus River, Pakistan

    Directory of Open Access Journals (Sweden)

    Sadiq I. Khan

    2014-03-01

    Full Text Available Flood monitoring was conducted using multi-sensor data from space-borne optical, and microwave sensors; with cross-validation by ground-based rain gauges and streamflow stations along the Indus River; Pakistan. First; the optical imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS was processed to delineate the extent of the 2010 flood along Indus River; Pakistan. Moreover; the all-weather all-time capability of higher resolution imagery from the Advanced Synthetic Aperture Radar (ASAR is used to monitor flooding in the lower Indus river basin. Then a proxy for river discharge from the Advanced Microwave Scanning Radiometer (AMSR-E aboard NASA’s Aqua satellite and rainfall estimates from the Tropical Rainfall Measuring Mission (TRMM are used to study streamflow time series and precipitation patterns. The AMSR-E detected water surface signal was cross-validated with ground-based river discharge observations at multiple streamflow stations along the main Indus River. A high correlation was found; as indicated by a Pearson correlation coefficient of above 0.8 for the discharge gauge stations located in the southwest of Indus River basin. It is concluded that remote-sensing data integrated from multispectral and microwave sensors could be used to supplement stream gauges in sparsely gauged large basins to monitor and detect floods.

  13. GPM, AMSR2 GCOMW1 Level 1C Common Calibrated Brightness Temperature VV02A

    Data.gov (United States)

    National Aeronautics and Space Administration — 1CAMSR2 contains common calibrated brightness temperature from the AMSR2 passive microwave instrument flown on the GCOMW1 satellite. This products contains 6...

  14. GPM, AMSR2 GCOMW1 Level 1C Common Calibrated Brightness Temperature VV03A

    Data.gov (United States)

    National Aeronautics and Space Administration — 1CAMSR2 contains common calibrated brightness temperature from the AMSR2 passive microwave instrument flown on the GCOMW1 satellite. This products contains 6...

  15. Recent Improvements in AMSR2 Ground-Based RFI Filtering

    Science.gov (United States)

    Scott, J. P.; Gentemann, C. L.; Wentz, F. J.

    2015-12-01

    Passive satellite radiometer measurements in the microwave frequencies (6-89 GHz) are useful in providing geophysical retrievals of sea surface temperature (SST), atmospheric water vapor, wind speed, rain rate, and more. However, radio frequency interference (RFI) is one of the fastest growing sources of error in these retrievals. RFI can originate from broadcasting satellites, as well as from ground-based instrumentation that makes use of the microwave range. The microwave channel bandwidths used by passive satellite radiometers are often wider than the protected bands allocated for this type of remote sensing, a common practice in microwave radiometer design used to reduce the effect of instrument noise in the observed signal. However, broad channel bandwidths allow greater opportunity for RFI to affect these observations and retrievals. For ground-based RFI, a signal is broadcast directly into the atmosphere which may interfere with the radiometer - its antenna, cold mirror, hot load or the internal workings of the radiometer itself. It is relatively easy to identify and flag RFI from large sources, but more difficult to do so from small, sporadic sources. Ground-based RFI has high spatial and temporal variability, requiring constant, automated detection and removal to avoid spurious trends leaching into the geophysical retrievals. Ascension Island in the South Atlantic Ocean has been one of these notorious ground-based RFI sources, affecting many microwave radiometers, including the AMSR2 radiometer onboard JAXA's GCOM-W1 satellite. Ascension Island RFI mainly affects AMSR2's lower frequency channels (6.9, 7.3, and 10.65 GHz) over a broad spatial region in the South Atlantic Ocean, which makes it challenging to detect and flag this RFI using conventional channel and geophysical retrieval differencing techniques. The authors have developed a new method of using the radiometer's earth counts and hot counts, for the affected channels, to detect an Ascension Island

  16. Active-Layer Soil Moisture Content Regional Variations in Alaska and Russia by Ground-Based and Satellite-Based Methods, 2002 Through 2014

    Science.gov (United States)

    Muskett, Reginald; Romanovsky, Vladimir; Cable, William; Kholodov, Alexander

    2016-04-01

    Soil moisture is a vital physical parameter of the active-layer in permafrost environments, and associated biological and geophysical processes operative at the microscopic to hemispheric spatial scales and at hourly to multidecadal time scales. While in-situ measurements can give the highest quality of information on a site-specific basis, the vast permafrost terrains of North America and Eurasia require space-based techniques for assessments of cause and effect and long-term changes and impacts from the changes of permafrost and the active-layer. Satellite-based 6.925 and 10.65 GHz sensor algorithmic retrievals of soil moisture by Advanced Microwave Scanning Radiometer - Earth Observation System (AMSR-E) onboard NASA-Aqua and follow-on AMSR2 onboard JAXA-Global Change Observation Mission - Water-1 are ongoing since July 2002. Accurate land-surface temperature and vegetation parameters are critical to the success of passive microwave algorithmic retrieval schemes. Strategically located soil moisture measurements are needed for spatial and temporal co-location evaluation and validation of the space-based algorithmic estimates. We compare on a daily basis ground-based (subsurface-probe) 50- and 70-MHz radio-frequency soil moisture measurements with NASA- and JAXA-algorithmic retrieval passive microwave retrievals. We find improvements in performance of the JAXA-algorithm (AMSR-E reprocessed and AMSR2 ongoing) relative to the earlier NASA-algorithm version. In the boreal forest regions accurate land-surface temperatures and vegetation parameters are still needed for algorithmic retrieval success. Over the period of AMSR-E retrievals we find evidence of at the high northern latitudes of growing terrestrial radio-frequency interference in the 10.65 GHz channel soil moisture content. This is an important error source for satellite-based active and passive microwave remote sensing soil moisture retrievals in Arctic regions that must be addressed. Ref: Muskett, R

  17. A Prototype Hail Detection Algorithm and Hail Climatology Developed with the Advanced Microwave Sounding Unit (AMSU)

    Science.gov (United States)

    Ferraro, Ralph; Beauchamp, James; Cecil, Dan; Heymsfeld, Gerald

    2015-01-01

    In previous studies published in the open literature, a strong relationship between the occurrence of hail and the microwave brightness temperatures (primarily at 37 and 85 GHz) was documented. These studies were performed with the Nimbus-7 SMMR, the TRMM Microwave Imager (TMI) and most recently, the Aqua AMSR-E sensor. This lead to climatologies of hail frequency from TMI and AMSR-E, however, limitations include geographical domain of the TMI sensor (35 S to 35 N) and the overpass time of the Aqua satellite (130 am/pm local time), both of which reduce an accurate mapping of hail events over the global domain and the full diurnal cycle. Nonetheless, these studies presented exciting, new applications for passive microwave sensors. Since 1998, NOAA and EUMETSAT have been operating the AMSU-A/B and the MHS on several operational satellites: NOAA-15 through NOAA-19; MetOp-A and -B. With multiple satellites in operation since 2000, the AMSU/MHS sensors provide near global coverage every 4 hours, thus, offering a much larger time and temporal sampling than TRMM or AMSR-E. With similar observation frequencies near 30 and 85 GHz and additionally three at the 183 GHz water vapor band, the potential to detect strong convection associated with severe storms on a more comprehensive time and space scale exists. In this study, we develop a prototype AMSU-based hail detection algorithm through the use of collocated satellite and surface hail reports over the continental U.S. for a 12-year period (2000-2011). Compared with the surface observations, the algorithm detects approximately 40 percent of hail occurrences. The simple threshold algorithm is then used to generate a hail climatology that is based on all available AMSU observations during 2000-11 that is stratified in several ways, including total hail occurrence by month (March through September), total annual, and over the diurnal cycle. Independent comparisons are made compared to similar data sets derived from other

  18. Data sets for snow cover monitoring and modelling from the National Snow and Ice Data Center

    Science.gov (United States)

    Holm, M.; Daniels, K.; Scott, D.; McLean, B.; Weaver, R.

    2003-04-01

    A wide range of snow cover monitoring and modelling data sets are pending or are currently available from the National Snow and Ice Data Center (NSIDC). In-situ observations support validation experiments that enhance the accuracy of remote sensing data. In addition, remote sensing data are available in near-real time, providing coarse-resolution snow monitoring capability. Time series data beginning in 1966 are valuable for modelling efforts. NSIDC holdings include SMMR and SSM/I snow cover data, MODIS snow cover extent products, in-situ and satellite data collected for NASA's recent Cold Land Processes Experiment, and soon-to-be-released ASMR-E passive microwave products. The AMSR-E and MODIS sensors are part of NASA's Earth Observing System flying on the Terra and Aqua satellites Characteristics of these NSIDC-held data sets, appropriateness of products for specific applications, and data set access and availability will be presented.

  19. Change in Water Cycle- Important Issue on Climate Earth System

    Science.gov (United States)

    Singh, Pratik

    climate forecasts. Aqua is a major mission of the Earth Observing System (EOS), an international program centered in NASA's Earth Science Enterprise to study the Earth in detail from the unique vantage point of space. Focused on key measurements identified by a consensus of U.S. and international scientists, EOS is further enabling studies of the complex interactions amongst the Earth's land, ocean, air, ice and biological systems. Aqua's contributions to monitoring water in the Earth's environment will involve all six of Aqua's instruments: the Atmospheric Infrared Sounder (AIRS), the Advanced Microwave Sounding Unit (AMSU), the Humidity Sounder for Brazil (HSB), the Advanced Microwave Scanning Radiometer- Earth Observing System (AMSR-E), the Moderate Resolution Imaging Spectroradiometer (MODIS), and Clouds and the Earth's Radiant Energy System (CERES). Frozen water in the oceans, in the form of sea ice, will be examined with both AMSR-E and MODIS data, the former allowing routine monitoring of sea ice at a coarse resolution and the latter providing greater spatial resolution but only under cloud-free conditions. Sea ice can insulate the underlying liquid water against heat loss to the often frigid overlying polar atmosphere and also reflects sunlight that would otherwise be available to warm the ocean. AMSR-E measurements will allow the routine derivation of sea ice concentrations in both polar regions, through taking advantage of the marked contrast in microwave emissions of sea ice and liquid water. This will continue, with improved resolution and accuracy, a 22-year satellite record of changes in the extent of polar ice. MODIS, with its finer resolution, will permit the identification of individual ice flows, when unobscured by clouds. AMSR-E and MODIS will also provide monitoring, the AIRS/AMSU/HSB combination will provide more-accurate space-based measurements of atmospheric temperature and water vapor than have ever been obtained before, with the highest vertical

  20. Satellite retrieval of hurricane wind speeds using the AMSR2 microwave radiometer

    Science.gov (United States)

    Yao, Panpan; Wan, Jianhua; Wang, Jin; Zhang, Jie

    2015-09-01

    The AMSR2 microwave radiometer is the main payload of the GCOM-W1 satellite, launched by the Japan Aerospace Exploration Agency in 2012. Based on the pre-launch information extraction algorithm, the AMSR2 enables remote monitoring of geophysical parameters such as sea surface temperature, wind speed, water vapor, and liquid cloud water content. However, rain alters the properties of atmospheric scattering and absorption, which contaminates the brightness temperatures measured by the microwave radiometer. Therefore, it is difficult to retrieve AMSR2-derived sea surface wind speeds under rainfall conditions. Based on microwave radiative transfer theory, and using AMSR2 L1 brightness temperature data obtained in August 2012 and NCEP reanalysis data, we studied the sensitivity of AMSR2 brightness temperatures to rain and wind speed, from which a channel combination of brightness temperature was established that is insensitive to rainfall, but sensitive to wind speed. Using brightness temperatures obtained with the proposed channel combination as input parameters, in conjunction with HRD wind field data, and adopting multiple linear regression and BP neural network methods, we established an algorithm for hurricane wind speed retrieval under rainfall conditions. The results showed that the standard deviation and relative error of retrievals, obtained using the multiple linear regression algorithm, were 3.1 m/s and 13%, respectively. However, the standard deviation and relative error of retrievals obtained using the BP neural network algorithm were better (2.1 m/s and 8%, respectively). Thus, the results of this paper preliminarily verified the feasibility of using microwave radiometers to extract sea surface wind speeds under rainfall conditions.

  1. Thin Ice Area Extraction in the Sea of Okhotsk from GCOM-W1/AMSR2 Data

    Science.gov (United States)

    Cho, K.; Sato, Y.; Naoki, K.

    2016-06-01

    Passive microwave radiometers on-board satellites can penetrate clouds and can monitor the global sea ice distribution on daily basis. The authors have developed an algorithm to extract thin ice area in the Sea of Okhotsk from the passive microwave sensor AMSR2 on-board GCOM-W1 satellite. The algorithm uses the brightness temperature scatter plots of AMSR2 19 GHz polarization difference(V-H) vs. 19 GHz V polarization. The results were verified using simultaneously collected MODIS images in the Sea of Okhotsk. The most of the thin ice areas visually identified in the MODIS images were automatically extracted from AMSR2 data using the algorithm.

  2. Detection of radio frequency interference over ocean

    Science.gov (United States)

    Tian, Xiaoxu

    The geostationary satellite television (TV) signals that are reflected off the ocean surfaces could enter the AMSR-E antenna, resulting in RFI (Radio Frequency Interference) contamination in AMSR-E 10.65 and 18.7 GHz channels. If not detected, the presence of RFI signals can result in false retrievals of oceanic environmental parameters (e.g., sea surface temperature, sea surface wind speed, rain water path) from microwave imaging radiance measurements. This study first examined the geometric relationship between the RFI source, geostationary TV satellite, and AMSR-E observation. Then a normalized Principal Component Analysis (NPCA) method is proposed and applied for RFI detection over oceans in Advanced Microwave Scanning Radiometer (AMSR)-E observations. It is found that the RFI-contaminated observations on AMSR-E descending node at 10.65 and 18.7 GHz can be successively detected near coastal areas surrounding Europe and United States continents. The results yielded from the geometric examination at another angle verify those signals detected with NPCA. The proposed NPCA algorithm is applicable in an operational environment for fast data processing and data dissemination, and is different from earlier methods, which often require a priori information.

  3. Assessing the Relative Performance of Microwave-Based Satellite Rain Rate Retrievals Using TRMM Ground Validation Data

    Science.gov (United States)

    Wolff, David B.; Fisher, Brad L.

    2011-01-01

    Space-borne microwave sensors provide critical rain information used in several global multi-satellite rain products, which in turn are used for a variety of important studies, including landslide forecasting, flash flood warning, data assimilation, climate studies, and validation of model forecasts of precipitation. This study employs four years (2003-2006) of satellite data to assess the relative performance and skill of SSM/I (F13, F14 and F15), AMSU-B (N15, N16 and N17), AMSR-E (Aqua) and the TRMM Microwave Imager (TMI) in estimating surface rainfall based on direct instantaneous comparisons with ground-based rain estimates from Tropical Rainfall Measuring Mission (TRMM) Ground Validation (GV) sites at Kwajalein, Republic of the Marshall Islands (KWAJ) and Melbourne, Florida (MELB). The relative performance of each of these satellite estimates is examined via comparisons with space- and time-coincident GV radar-based rain rate estimates. Because underlying surface terrain is known to affect the relative performance of the satellite algorithms, the data for MELB was further stratified into ocean, land and coast categories using a 0.25deg terrain mask. Of all the satellite estimates compared in this study, TMI and AMSR-E exhibited considerably higher correlations and skills in estimating/observing surface precipitation. While SSM/I and AMSU-B exhibited lower correlations and skills for each of the different terrain categories, the SSM/I absolute biases trended slightly lower than AMSR-E over ocean, where the observations from both emission and scattering channels were used in the retrievals. AMSU-B exhibited the least skill relative to GV in all of the relevant statistical categories, and an anomalous spike was observed in the probability distribution functions near 1.0 mm/hr. This statistical artifact appears to be related to attempts by algorithm developers to include some lighter rain rates, not easily detectable by its scatter-only frequencies. AMSU

  4. The Transition of High-Resolution NASA MODIS Sea Surface Temperatures into the WRF Environmental Modeling System

    Science.gov (United States)

    Case, Jonathan L.; Jedlove, Gary J.; Santos, Pablo; Medlin, Jeffrey M.; Rozumalski, Robert A.

    2009-01-01

    format for a seamless incorporation into WRF via the WPS utilities. The full-resolution, 1-km MODIS product is sub-sampled to 2-km grid spacing due to limitations in handling very large dimensions in the GRIB-1 data format. The GRIB-1 files are posted online at ftp://ftp.nsstc.org/sstcomp/WRF/, which is directly accessed by the WRF EMS scripts. The MODIS SST composites are also downloaded to the EMS data server, which is accessible by the WRF EMS users and NWS WFOs. The SPoRT MODIS SST composite provides the model with superior detail of the ocean gradients around Florida and surrounding waters, whereas the operational RTG SST typically depicts a relatively smooth field and is not able to capture sharp horizontal gradients in SST. Differences of 2-3 C are common over small horizontal distances, leading to enhanced SST gradients on either side of the Gulf Stream and along the edges of the cooler shelf waters. These sharper gradients can in turn produce atmospheric responses in simulated temperature and wind fields as depicted in LaCasse et al. Differences in atmospheric verification statistics over a several month study were generally small in the vicinity of south Florida; however, the validation of SSTs at specific buoy locations revealed important improvements in the biases and RMS errors, especially in the vicinity of the cooler shelf waters off the east-central Florida coast. A current weakness in the MODIS SST product is the occurrence of occasional discontinuities caused by high latency in SST coverage due to persistent cloud cover. An enhanced method developed by Jedlovec et al. (2009, GHRSST User Symposium) reduces the occurrence of these problems by adding Advanced Microwave Scanning Radiometer -- EOS (AMSR-E) SST data to the compositing process. Enhanced SST composites are produced over the ocean regions surrounding the Continental U.S. at four times each day corresponding to Terra and Aqua equator crossing times. For a given day and overpass time, both MODInd

  5. Antihyperlipidemic and antioxidant effects of Samhwangsasimtang aqua-acupuncture

    Directory of Open Access Journals (Sweden)

    Lee Eun

    2005-02-01

    Full Text Available Effects of Samhwangsasimtang aqua-acupuncture at gansoo(B18 and chungwan(CV12 on antihyperlipidemic and antioxidant were investigated in rat fed high fat diet. Concentrations of triglyceride, free fatty acids, lipoprotein and glucose in plasma showed a tendency to decrease in the aqua-acupuncture groups. In plasma lipid composition, total cholesterol and LDL- cholesterol showed a tendency to decrease in aqua-acupuncture groups, however the values of HDL-cholesterol showed no significantly different in the treatment groups. Concentration of thiobarbituric acid reactive substances(TBARS in plasma and liver showed a low in the aqua-acupuncture groups. The values of glutathione peroxidase(GSH-Px and catalase(CAT activity showed a tendency to increase in aqua-acupuncture groups. However the values of superoxide dismutase(SOD activity showed no significantly different in the treatment groups.

  6. Visual Modeling for Aqua Ventus I off Monhegan Island, ME

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, Luke A.; Whiting, Jonathan M.; Copping, Andrea E.

    2013-11-27

    To assist the University of Maine in demonstrating a clear pathway to project completion, PNNL has developed visualization models of the Aqua Ventus I project that accurately depict the Aqua Ventus I turbines from various points on Monhegain Island, ME and the surrounding area. With a hub height of 100 meters, the Aqua Ventus I turbines are large and may be seen from many areas on Monhegan Island, potentially disrupting important viewsheds. By developing these visualization models, which consist of actual photographs taken from Monhegan Island and the surrounding area with the Aqua Ventus I turbines superimposed within each photograph, PNNL intends to support the project’s siting and permitting process by providing the Monhegan Island community and various other stakeholders with a probable glimpse of how the Aqua Ventus I project will appear.

  7. AN ACTIVE-PASSIVE COMBINED ALGORITHM FOR HIGH SPATIAL RESOLUTION RETRIEVAL OF SOIL MOISTURE FROM SATELLITE SENSORS (Invited)

    Science.gov (United States)

    Lakshmi, V.; Mladenova, I. E.; Narayan, U.

    2009-12-01

    Soil moisture is known to be an essential factor in controlling the partitioning of rainfall into surface runoff and infiltration and solar energy into latent and sensible heat fluxes. Remote sensing has long proven its capability to obtain soil moisture in near real-time. However, at the present time we have the Advanced Scanning Microwave Radiometer (AMSR-E) on board NASA’s AQUA platform is the only satellite sensor that supplies a soil moisture product. AMSR-E coarse spatial resolution (~ 50 km at 6.9 GHz) strongly limits its applicability for small scale studies. A very promising technique for spatial disaggregation by combining radar and radiometer observations has been demonstrated by the authors using a methodology is based on the assumption that any change in measured brightness temperature and backscatter from one to the next time step is due primarily to change in soil wetness. The approach uses radiometric estimates of soil moisture at a lower resolution to compute the sensitivity of radar to soil moisture at the lower resolution. This estimate of sensitivity is then disaggregated using vegetation water content, vegetation type and soil texture information, which are the variables on which determine the radar sensitivity to soil moisture and are generally available at a scale of radar observation. This change detection algorithm is applied to several locations. We have used aircraft observed active and passive data over Walnut Creek watershed in Central Iowa in 2002; the Little Washita Watershed in Oklahoma in 2003 and the Murrumbidgee Catchment in southeastern Australia for 2006. All of these locations have different soils and land cover conditions which leads to a rigorous test of the disaggregation algorithm. Furthermore, we compare the derived high spatial resolution soil moisture to in-situ sampling and ground observation networks

  8. A mission planning tool for the Characterization of Sea Ice (CASIE) mission to Svalbard, Norway, in July 2009

    Science.gov (United States)

    Kerr, J. M.; Enomoto, F.; Johan, S.; Crocker, R. I.; Fladeland, M. M.; Long, D.; Maslanik, J. A.; Sullivan, D.; Wegrzyn, K.

    2009-12-01

    Team members from NASA Ames Research Center developed a mission planning tool using Google Earth to support mission planning and monitoring during the Characterization of Sea Ice (CASIE) 2009 Mission to Svalbard, Norway. The tool allowed both deployed and non-deployed team members to view near-real time satellite imagery, ancillary information and flight paths before, during and after flights. MODIS, QuikSCAT, and AMSR-E data were displayed in Google Earth as ground overlays. MODIS data included two true color images (one each from Aqua and Terra) and a false color image (bands 3, 6, and 7) from Terra. The images were converted from GeoTIFF format to KML format using GDAL and provided cloud information to flight planners. The QuikSCAT and AMSR-E satellite imagery provided information on ice location and concentration, which allowed flight planners to locate areas for data collection. Ancillary information included sounding data, icing and snow cover forecasts, cloud pressure, perceptible water, and surface temperature data. Before flying, flight paths were created in Google Earth and then converted into shapefiles for input into flight software. While in-flight, the plane sent position, temperature, and humidity data to the base station in Ny-Ålesund. These data were converted into KML format and displayed within Google Earth in near-real time. The simultaneous display of satellite data, weather forecasts, and real-time data from the aircraft allowed mission planners to make real time mission operation decisions and allowed for remote mission monitoring by team members not deployed to Svalbard.

  9. Passive Microwave Precipitation Detection Biases: Relationship to Environment

    Science.gov (United States)

    Viramontez, A.; Rapp, A. D.

    2015-12-01

    Accurate satellite precipitation estimates are essential for understanding the long-term variability in the global hydrologic cycle and for constraining global climate models. Spaceborne precipitation estimates depend heavily on passive microwave remote sensors due to the large spatial coverage and long record of observations available from such sensors; however, light precipitation is frequently undetected or underestimated by passive microwave rainfall retrievals. Observations from the CloudSat Profiling Radar (CPR) and the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) provide a unique opportunity for long-term collocated precipitation measurements from passive microwave sensors and an active radar with sensitivity to very light precipitation that can be used to assess the precipitation detection biases. For this study, collocated measurements from AMSR-E and CloudSat during 2008 will be used to identify environments where AMSR-E underestimates precipitation. Environmental variables from the ECMWF Reanalysis (ERA-Interim) will be used to understand the characteristics of the large-scale and thermodynamic environments associated with AMSR-E precipitation biases. A preliminary comparison of CPR rain rates and AMSR-E Level-2B rain rates show a large fraction of rain missed by AMSR-E, with nearly 80% of missed light rain in regions with SSTs below 25°C. This is consistent with prior studies showing large detection biases in regions of large-scale subsidence. The relationship between precipitation biases and other factors such as 2 m air temperature, column water vapor, lower tropospheric stability, and vertical velocity will be explored.

  10. Evaluation of AMSR2 soil moisture products over the contiguous United States using in situ data from the International Soil Moisture Network

    Science.gov (United States)

    Wu, Qiusheng; Liu, Hongxing; Wang, Lei; Deng, Chengbin

    2016-03-01

    High quality soil moisture datasets are required for various environmental applications. The launch of the Advanced Microwave Scanning Radiometer 2 (AMSR2) on board the Global Change Observation Mission 1-Water (GCOM-W1) in May 2012 has provided global near-surface soil moisture data, with an average revisit frequency of two days. Since AMSR2 is a new passive microwave system in operation, it is very important to evaluate the quality of AMSR2 products before widespread utilization of the data for scientific research. In this paper, we provide a comprehensive evaluation of the AMSR2 soil moisture products retrieved by the Japan Aerospace Exploration Agency (JAXA) algorithm. The evaluation was performed for a three-year period (July 2012-June 2015) over the contiguous United States. The AMSR2 soil moisture products were evaluated by comparing ascending and descending overpass products to each other as well as comparing them to in situ soil moisture observations of 598 monitoring stations obtained from the International Soil Moisture Network (ISMN). The accuracy of AMSR2 soil moisture product was evaluated against several types of monitoring networks, and for different land cover types and ecoregions. Three performance metrics, including mean difference (MD), root mean squared difference (RMSD), and correlation coefficient (R), were used in our accuracy assessment. Our evaluation results revealed that AMSR2 soil moisture retrievals are generally lower than in situ measurements. The AMSR2 soil moisture retrievals showed the best agreement with in situ measurements over the Great Plains and the worst agreement over forested areas. This study offers insights into the suitability and reliability of AMSR2 soil moisture products for different ecoregions. Although AMSR2 soil moisture retrievals represent useful and effective measurements for some regions, further studies are required to improve the data accuracy.

  11. AquaCrop模型及其研究进展%Review on the Processes of AquaCrop Model

    Institute of Scientific and Technical Information of China (English)

    王亮; 魏新平

    2014-01-01

    结合国内外有关AquaCrop模型的研究工作,以研究模型的应用领域为基点,对AquaCrop模型运用成果的特点进行归纳.在此基础上,指出了模型在理论合理性和实际适用性等方面存在的问题,并对AquaCrop模型的发展前景进行了展望,以期为我国作物模型的研究提供借鉴.

  12. SST, Aqua MODIS, NPP, 0.0125 degrees, Indonesia, Daytime

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch provides SST data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging Spectroradiometer (MODIS) carried aboard...

  13. AIRS/Aqua Level 2G Precipitation Estimate V005

    Data.gov (United States)

    National Aeronautics and Space Administration — The Atmospheric Infrared Sounder (AIRS) is a facility instrument aboard the second Earth Observing System (EOS) polar-orbiting platform, EOS Aqua. In combination...

  14. Value of Available Global Soil Moisture Products for Agricultural Monitoring

    Science.gov (United States)

    Mladenova, Iliana; Bolten, John; Crow, Wade; de Jeu, Richard

    2016-04-01

    The first operationally derived and publicly distributed global soil moil moisture product was initiated with the launch of the Advanced Scanning Microwave Mission on the NASA's Earth Observing System Aqua satellite (AMSR-E). AMSR-E failed in late 2011, but its legacy is continued by AMSR2, launched in 2012 on the JAXA Global Change Observation Mission-Water (GCOM-W) mission. AMSR is a multi-frequency dual-polarization instrument, where the lowest two frequencies (C- and X-band) were used for soil moisture retrieval. Theoretical research and small-/field-scale airborne campaigns, however, have demonstrated that soil moisture would be best monitored using L-band-based observations. This consequently led to the development and launch of the first L-band-based mission-the ESA's Soil Moisture Ocean Salinity (SMOS) mission (2009). In early 2015 NASA launched the second L-band-based mission, the Soil Moisture Active Passive (SMAP). These satellite-based soil moisture products have been demonstrated to be invaluable sources of information for mapping water stress areas, crop monitoring and yield forecasting. Thus, a number of agricultural agencies routinely utilize and rely on global soil moisture products for improving their decision making activities, determining global crop production and crop prices, identifying food restricted areas, etc. The basic premise of applying soil moisture observations for vegetation monitoring is that the change in soil moisture conditions will precede the change in vegetation status, suggesting that soil moisture can be used as an early indicator of expected crop condition change. Here this relationship was evaluated across multiple microwave frequencies by examining the lag rank cross-correlation coefficient between the soil moisture observations and the Normalized Difference Vegetation Index (NDVI). A main goal of our analysis is to evaluate and inter-compare the value of the different soil moisture products derived using L-band (SMOS

  15. Corrections to the MODIS Aqua Calibration Derived From MODIS Aqua Ocean Color Products

    Science.gov (United States)

    Meister, Gerhard; Franz, Bryan Alden

    2013-01-01

    Ocean color products such as, e.g., chlorophyll-a concentration, can be derived from the top-of-atmosphere radiances measured by imaging sensors on earth-orbiting satellites. There are currently three National Aeronautics and Space Administration sensors in orbit capable of providing ocean color products. One of these sensors is the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite, whose ocean color products are currently the most widely used of the three. A recent improvement to the MODIS calibration methodology has used land targets to improve the calibration accuracy. This study evaluates the new calibration methodology and describes further calibration improvements that are built upon the new methodology by including ocean measurements in the form of global temporally averaged water-leaving reflectance measurements. The calibration improvements presented here mainly modify the calibration at the scan edges, taking advantage of the good performance of the land target trending in the center of the scan.

  16. EOS Aqua: Mission Status at Earth Science Constellation

    Science.gov (United States)

    Guit, Bill

    2016-01-01

    This is an EOS Aqua Mission Status presentation to be given at the MOWG meeting in Albuquerque NM. The topics to discus are: mission summary, spacecraft subsystems summary, recent and planned activities, inclination adjust maneuvers, propellant usage and lifetime estimate, and mission summary.

  17. Recent Improvements in Retrieving Near-Surface Air Temperature and Humidity Using Microwave Remote Sensing

    Science.gov (United States)

    Roberts, J. Brent

    2010-01-01

    Detailed studies of the energy and water cycles require accurate estimation of the turbulent fluxes of moisture and heat across the atmosphere-ocean interface at regional to basin scale. Providing estimates of these latent and sensible heat fluxes over the global ocean necessitates the use of satellite or reanalysis-based estimates of near surface variables. Recent studies have shown that errors in the surface (10 meter)estimates of humidity and temperature are currently the largest sources of uncertainty in the production of turbulent fluxes from satellite observations. Therefore, emphasis has been placed on reducing the systematic errors in the retrieval of these parameters from microwave radiometers. This study discusses recent improvements in the retrieval of air temperature and humidity through improvements in the choice of algorithms (linear vs. nonlinear) and the choice of microwave sensors. Particular focus is placed on improvements using a neural network approach with a single sensor (Special Sensor Microwave/Imager) and the use of combined sensors from the NASA AQUA satellite platform. The latter algorithm utilizes the unique sampling available on AQUA from the Advanced Microwave Scanning Radiometer (AMSR-E) and the Advanced Microwave Sounding Unit (AMSU-A). Current estimates of uncertainty in the near-surface humidity and temperature from single and multi-sensor approaches are discussed and used to estimate errors in the turbulent fluxes.

  18. Passive microwave precipitation detection biases: Relationship to cloud morphology

    Science.gov (United States)

    Marter, R. E.; Rapp, A. D.

    2015-12-01

    Accurate measurement of the Earth's hydrologic cycle requires a more precise understanding of precipitation accumulation and intensity on a global scale. While there is a long record of passive microwave satellite measurements, passive microwave rainfall retrievals often fail to detect light precipitation or have light rain intensity biases because they cannot differentiate between emission from cloud and rain water. Previous studies have shown that AMSR-E significantly underestimates rainfall occurrence and volume compared to CloudSat. This underestimation totals just below 0.6 mm/day quasi-globally (60S-60N), but there are larger regional variations related to the dominant cloud regime. This study aims to use Moderate Resolution Imaging Spectroradiometer (MODIS) and the 94-GHz CloudSat Cloud Profiling Radar (CPR), which has a high sensitivity to light rain, with the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) observations, to help better characterize the properties of clouds that lead to passive microwave rainfall detection biases. CPR cloud and precipitation retrievals. AMSR-E Level-2B Goddard Profiling 2010 Algorithm (GPROF 2010) rainfall retrievals, and MODIS cloud properties were collocated and analyzed for 2008. Results are consistent with past studies and show large passive microwave precipitation detection biases compared to CloudSat in stratocumulus and shallow cumulus regimes. A preliminary examination of cases where AMSR-E failed to detect precipitation detected by CloudSat shows that over 50% of missed warm precipitation occurs in clouds with top heights below 2 km. MODIS cloud microphysical and macrophysical properties, such as optical thickness, particle effective radius, and liquid water path will be analyzed when precipitation is detected by CloudSat and missed by AMSR-E. The overall goal is to understand how cloud morphology relates to detection biases.

  19. Environmental factors that determine the occurrence and seasonal dynamics of Aphanizomenon flos-aquae

    Directory of Open Access Journals (Sweden)

    Yoshimasa YAMAMOTO

    2009-02-01

    Full Text Available This study investigated the seasonal dynamics of two populations of Aphanizomenon flos-aquae Ralfs ex Bornet & Flahault var. flos-aquae and four populations of A. flos-aquae var. klebahnii Elenkin in eutrophic water bodies over 1 year from February 2006 to January 2007. The growth of A. flos-aquae var. flos-aquae was promoted at high temperatures even if in one case the biomass development was very low when other co-occurring cyanoprokaryotes (Anabaena spp. and Microcystis spp. were abundant. In contrast, the highest density of the other population of A. flos-aquae var. flos-aquae was observed in August when the population density of M. aeruginosa (Kützing Kützing reached an annual peak. A. flos-aquae var. flos-aquae usually bloomed in summer but could also tolerate low temperatures in the winter, and was present in relatively high densities. The populations of A. flos-aquae var. klebahnii observed in this study can be divided into three groups based on preferred temperature; three populations increased in winter, and the other increased in summer. Large biomasses of the low-temperature-adapted A. flos-aquae were observed mainly during winter when population densities of co-occurring cyanoprokaryotes (Anabaena spp., Microcystis spp. and Planktothrix raciborskii (Woloszynska Anagnostidis & Komárek were relatively low or almost absent. The increase in or existence of cooccurring cyanoprokaryotes during the summer resulted in a decrease of the A. flos-aquae population density. It was revealed that high temperatures (20-25 °C are suitable for maintaining A. flos-aquae var. klebahnii strains isolated from the study ponds, implying that low-temperature-adapted A. flos-aquae can grow over a wide range of water temperatures. The high-temperatureadapted A. flos-aquae var. klebahnii co-existed with M. aeruginosa during summer; however, its peak population density was significantly lower than those in previous years when M. aeruginosa was absent

  20. Summary of Terra and Aqua MODIS Long-Term Performance

    Science.gov (United States)

    Xiong, Xiaoxiong (Jack); Wenny, Brian N.; Angal, Amit; Barnes, William; Salomonson, Vincent

    2011-01-01

    Since launch in December 1999, the MODIS ProtoFlight Model (PFM) onboard the Terra spacecraft has successfully operated for more than 11 years. Its Flight Model (FM) onboard the Aqua spacecraft, launched in May 2002, has also successfully operated for over 9 years. MODIS observations are made in 36 spectral bands at three nadir spatial resolutions and are calibrated and characterized regularly by a set of on-board calibrators (OBC). Nearly 40 science products, supporting a variety of land, ocean, and atmospheric applications, are continuously derived from the calibrated reflectances and radiances of each MODIS instrument and widely distributed to the world-wide user community. Following an overview of MODIS instrument operation and calibration activities, this paper provides a summary of both Terra and Aqua MODIS long-term performance. Special considerations that are critical to maintaining MODIS data quality and beneficial for future missions are also discussed.

  1. Aqua-vanadyl ion interaction with Nafion® membranes

    Directory of Open Access Journals (Sweden)

    Vijayakumar eMurugesan

    2015-03-01

    Full Text Available Lack of comprehensive understanding about the interactions between Nafion membrane and battery electrolytes prevents the straightforward tailoring of optimal materials for redox flow battery applications. In this work, we analyzed the interaction between aqua-vanadyl cation and sulfonic sites within the pores of Nafion membranes using combined theoretical and experimental X-ray spectroscopic methods. Molecular level interactions namely solvent share and contact pair mechanisms are discussed based on Vanadium and Sulfur K-edge spectroscopic analysis.

  2. AMSR2 all-sky radiance assimilation and its impact on the analysis and forecast of Hurricane Sandy with a limited-area data assimilation system

    Directory of Open Access Journals (Sweden)

    Chun Yang

    2016-06-01

    Full Text Available A method to assimilate all-sky radiances from the Advanced Microwave Scanning Radiometer 2 (AMSR2 was developed within the Weather Research and Forecasting (WRF model's data assimilation (WRFDA system. The four essential elements are: (1 extending the community radiative transform model's (CRTM interface to include hydrometeor profiles; (2 using total water Qt as the moisture control variable; (3 using a warm-rain physics scheme for partitioning the Qt increment into individual increments of water vapour, cloud liquid water and rain; and (4 adopting a symmetric observation error model for all-sky radiance assimilation.Compared to a benchmark experiment with no AMSR2 data, the impact of assimilating clear-sky or all-sky AMSR2 radiances on the analysis and forecast of Hurricane Sandy (2012 was assessed through analysis/forecast cycling experiments using WRF and WRFDA's three-dimensional variational (3DVAR data assimilation scheme. With more cloud/precipitation-affected data being assimilated around tropical cyclone (TC core areas in the all-sky AMSR2 assimilation experiment, better analyses were obtained in terms of the TC's central sea level pressure (CSLP, warm-core structure and cloud distribution. Substantial (>20 % error reduction in track and CSLP forecasts was achieved from both clear-sky and all-sky AMSR2 assimilation experiments, and this improvement was consistent from the analysis time to 72-h forecasts. Moreover, the all-sky assimilation experiment consistently yielded better track and CSLP forecasts than the clear-sky did for all forecast lead times, due to a better analysis in the TC core areas. Positive forecast impact from assimilating AMSR2 radiances is also seen when verified against the European Center for Medium-Range Weather Forecasts (ECMWF analysis and the Stage IV precipitation analysis, with an overall larger positive impact from the all-sky assimilation experiment.

  3. The Aqua-Planet Experiment (APE): CONTROL SST Simulation

    Science.gov (United States)

    Blackburn, Michael; Williamson, David L.; Nakajima, Kensuke; Ohfuchi, Wataru; Takahashi, Yoshiyuki O.; Hayashi, Yoshi-Yuki; Nakamura, Hisashi; Ishiwatari, Masaki; Mcgregor, John L.; Borth, Hartmut; Wirth, Volkmar; Frank, Helmut; Bechtold, Peter; Wedi, Nils P.; Tomita, Hirofumi; Satoh, Masaki; Zhao, Ming; Held, Isaac M.; Suarez, Max J.; Lee, Myong-In; Watanabe, Masahiro; Kimoto, Masahide; Liu, Yimin; Wang, Zaizhi; Molod, Andrea M.; Rajendran, Kavirajan; Kotoh, Akio; Stratton, Rachel

    2013-01-01

    Climate simulations by 16 atmospheric general circulation models (AGCMs) are compared on an aqua-planet, a water-covered Earth with prescribed sea surface temperature varying only in latitude. The idealised configuration is designed to expose differences in the circulation simulated by different models. Basic features of the aqua-planet climate are characterised by comparison with Earth. The models display a wide range of behaviour. The balanced component of the tropospheric mean flow, and mid-latitude eddy covariances subject to budget constraints, vary relatively little among the models. In contrast, differences in damping in the dynamical core strongly influence transient eddy amplitudes. Historical uncertainty in modelled lower stratospheric temperatures persists in APE.Aspects of the circulation generated more directly by interactions between the resolved fluid dynamics and parameterized moist processes vary greatly. The tropical Hadley circulation forms either a single or double inter-tropical convergence zone (ITCZ) at the equator, with large variations in mean precipitation. The equatorial wave spectrum shows a wide range of precipitation intensity and propagation characteristics. Kelvin mode-like eastward propagation with remarkably constant phase speed dominates in most models. Westward propagation, less dispersive than the equatorial Rossby modes, dominates in a few models or occurs within an eastward propagating envelope in others. The mean structure of the ITCZ is related to precipitation variability, consistent with previous studies.The aqua-planet global energy balance is unknown but the models produce a surprisingly large range of top of atmosphere global net flux, dominated by differences in shortwave reflection by clouds. A number of newly developed models, not optimised for Earth climate, contribute to this. Possible reasons for differences in the optimised models are discussed.The aqua-planet configuration is intended as one component of an

  4. Global Change Observation Mission (GCOM)

    Science.gov (United States)

    Shimoda, Haruhisa

    In order to meet the requirements of Global Earth Observation System of Systems (GEOSS) as well as to continue the ADEOS and ADEOS2 missions, JAXA is now planning the GCOM mission which is composed of a series of satellites. There are two series of satellites, and they are now called GCOM-W and GCOM-C satellites. Both series are composed of 3 satellites with 5 years lifetime. Hence, 13 years of continuous observation can be assured with 1 year overlaps. The first satellite of GCOM-W will be launched in fiscal 2011 while the first one of GCOM-C will be launched in fiscal 2013. In regard to global warming, the GCOM intends the measurement of most factors involved in the energy and water cycle and material cycle, which are the main mechanisms determining climate change, and also analysis of the relevant processes. Within the material cycle, measurement of the carbon cycle is a key subject. In this particular field, the GCOM aims at estimating the primary production as well as carbon flux based on measurement data on land vegetation and phytoplankton. In regard to changes of the land environment, the measuring subjects are tropical forests and the global distribution of vegetation and its changes. In regard to the cryosphere, the sea ice concentration and snow coverage are measured and their interaction with the climate is analyzed. GCOM-W1 will carry AMSR2 (AMSR F/O). AMSR2 will be very similar to AMSR on ADEOS2 and AMSR-E on EOS-Aqua with some modifications. The aperture of AMSR2 is 2m, and AMSR2 will have more accurate hot load than AMSR. Two kinds of modification are intro-duced. One is to use an actively controlled thermal reflector over the hot load. This reflector is called a temperature controlled plate (TCP). Another modification is to shield the ambient emissions. GCOM-C1 will carry GLI F/O (called the second generation GLI : SGLI). The SGLI will be rather different from GLI on ADEOS2. The main targets of SGLI are atmospheric aerosols, coastal zone and land

  5. A Review on the Research and Application of AquaCrop Model%AquaCrop作物模型应用研究进展

    Institute of Scientific and Technical Information of China (English)

    王连喜; 吴建生; 李琪; 顾嘉熠; 薛红喜

    2015-01-01

    介绍了AquaCrop模型的基本原理以及研究和应用进展,重点介绍了AquaCrop模型的应用情况.AquaCrop模型在作物灌溉管理、种植制度、未来气候情景模拟中的应用已取得了较好成果.总结了AquaCrop模型当前应用应注意的问题,指出:AquaCrop模型的研究集中于单点尺度,在国内的研究多集中于模型的校正与验证,模型参数在我国的适用性还有待进一步验证;在严重水分胁迫条件下,会影响AquaCrop模型的模拟性能.最后,提出了未来发展的几点建议,以期为AquaCrop模型今后在我国的农业生产实践中起到指导作用.

  6. Early on-orbit calibration results from Aqua MODIS

    Science.gov (United States)

    Xiong, Xiaoxiong; Barnes, William L.

    2003-04-01

    Aqua MODIS, also known as the MODIS Flight Model 1 (FM1), was launched on May 4, 2002. It opened its nadir aperture door (NAD) on June 24, 2002, beginning its Earth observing mission. In this paper, we present early results from Aqua MODIS on-orbit calibration and characterization and assess the instrument's overall performance. MODIS has 36 spectral bands located on four focal plane assemblies (FPAs). Bands 1-19, and 26 with wavelengths from 0.412 to 2.1 microns are the reflective solar bands (RSB) that are calibrated on-orbit by a solar diffuser (SD). The degradation of the SD is tracked using a solar diffuser stability monitor (SDSM). The bands 20-25, and 27-36 with wavelengths from 3.75 to 14.5 microns are the thermal emissive bands (TEB) that are calibrated on-orbit by a blackbody (BB). Early results indicate that the on-orbit performance has been in good agreement with the predications determined from pre-launch measurements. Except for band 21, the low gain fire band, band 6, known to have some inoperable detectors from pre-launch characterization, and one noisy detector in band 36, all of the detectors' noise characterizations are within their specifications. Examples of the sensor's short-term and limited long-term responses in both TEB and RSB will be provided to illustrate the sensor's on-orbit stability. In addition, we will show some of the improvements that Aqua MODIS made over its predecessor, Terra MODIS (Protoflight Model - PFM), such as removal of the optical leak into the long-wave infrared (LWIR) photoconductive (PC) bands and reduction of electronic crosstalk and out-of-band (OOB) thermal leak into the short-wave infrared (SWIR) bands.

  7. catena-Poly[[di-μ-aqua-bis[aquacobalt(II

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available The title compound, [Co2(C9H4N2O42(H2O4]n, is a one-dimensional polymeric complex with bridging 1H-benzimidazole-5,6-dicarboxylate and aqua ligands. The CoII cation has an octahedral coordination environment provided by an NO5 donor set. Adjacent polymeric chains extended along the [100] direction are linked by O—H...O and N—H...O hydrogen bonds, generating a three-dimensional network.

  8. Structural and Functional Characterization of a Novel Family of Cyclophilins, the AquaCyps.

    Science.gov (United States)

    Jakob, Roman P; Schmidpeter, Philipp A M; Koch, Johanna R; Schmid, Franz X; Maier, Timm

    2016-01-01

    Cyclophilins are ubiquitous cis-trans-prolyl isomerases (PPIases) found in all kingdoms of life. Here, we identify a novel family of cyclophilins, termed AquaCyps, which specifically occurs in marine Alphaproteobacteria, but not in related terrestric species. In addition to a canonical PPIase domain, AquaCyps contain large extensions and insertions. The crystal structures of two representatives from Hirschia baltica, AquaCyp293 and AquaCyp300, reveal the formation of a compact domain, the NIC domain, by the N- and C-terminal extensions together with a central insertion. The NIC domain adopts a novel mixed alpha-helical, beta-sheet fold that is linked to the cyclophilin domain via a conserved disulfide bond. In its overall fold, AquaCyp293 resembles AquaCyp300, but the two proteins utilize distinct sets of active site residues, consistent with differences in their PPIase catalytic properties. While AquaCyp293 is a highly active general PPIase, AquaCyp300 is specific for hydrophobic substrate peptides and exhibits lower overall activity. PMID:27276069

  9. Structural and Functional Characterization of a Novel Family of Cyclophilins, the AquaCyps.

    Directory of Open Access Journals (Sweden)

    Roman P Jakob

    Full Text Available Cyclophilins are ubiquitous cis-trans-prolyl isomerases (PPIases found in all kingdoms of life. Here, we identify a novel family of cyclophilins, termed AquaCyps, which specifically occurs in marine Alphaproteobacteria, but not in related terrestric species. In addition to a canonical PPIase domain, AquaCyps contain large extensions and insertions. The crystal structures of two representatives from Hirschia baltica, AquaCyp293 and AquaCyp300, reveal the formation of a compact domain, the NIC domain, by the N- and C-terminal extensions together with a central insertion. The NIC domain adopts a novel mixed alpha-helical, beta-sheet fold that is linked to the cyclophilin domain via a conserved disulfide bond. In its overall fold, AquaCyp293 resembles AquaCyp300, but the two proteins utilize distinct sets of active site residues, consistent with differences in their PPIase catalytic properties. While AquaCyp293 is a highly active general PPIase, AquaCyp300 is specific for hydrophobic substrate peptides and exhibits lower overall activity.

  10. An unprecedented tetranuclear niobium aqua ion with a capping μ4-sulfido ligand

    DEFF Research Database (Denmark)

    Ooi, Bee Lean; Søtofte, Inger

    2005-01-01

    A new niobium aqua ion, with an unprecedented metal-metal bonded tetranuclear Nb4(μ4-S)(μ2-O)54+ core, is obtained upon treatment of Zn-reduced ethanolic solutions of NbCl5 with HCl in the presence of a sulfide source. The red aqua ion, obtained upon cation-exchange chromatography, forms readily...

  11. Structural and Functional Characterization of a Novel Family of Cyclophilins, the AquaCyps

    Science.gov (United States)

    Jakob, Roman P.; Schmidpeter, Philipp A. M.; Koch, Johanna R.; Schmid, Franz X.; Maier, Timm

    2016-01-01

    Cyclophilins are ubiquitous cis-trans-prolyl isomerases (PPIases) found in all kingdoms of life. Here, we identify a novel family of cyclophilins, termed AquaCyps, which specifically occurs in marine Alphaproteobacteria, but not in related terrestric species. In addition to a canonical PPIase domain, AquaCyps contain large extensions and insertions. The crystal structures of two representatives from Hirschia baltica, AquaCyp293 and AquaCyp300, reveal the formation of a compact domain, the NIC domain, by the N- and C-terminal extensions together with a central insertion. The NIC domain adopts a novel mixed alpha-helical, beta-sheet fold that is linked to the cyclophilin domain via a conserved disulfide bond. In its overall fold, AquaCyp293 resembles AquaCyp300, but the two proteins utilize distinct sets of active site residues, consistent with differences in their PPIase catalytic properties. While AquaCyp293 is a highly active general PPIase, AquaCyp300 is specific for hydrophobic substrate peptides and exhibits lower overall activity. PMID:27276069

  12. Operational Experiences in Planning and Reconstructing Aqua Inclination Maneuvers

    Science.gov (United States)

    Rand, David; Reilly, Jacqueline; Schiff, Conrad

    2004-01-01

    As the lead satellite in NASA's growing Earth Observing System (EOS) PM constellation, it is increasingly critical that Aqua maintain its various orbit requirements. The two of interest for this paper are maintaining an orbit inclination that provides for a consistent mean local time and a semi-major Axis (SMA) that allows for ground track repeatability. Maneuvers to adjust the orbit inclination involve several flight dynamics constraints and complexities which make planning such maneuvers challenging. In particular, coupling between the orbital and attitude degrees of freedom lead to changes in SMA when changes in inclination are effected. A long term mission mean local time trend analysis was performed in order to determine the size and placement of the required inclination maneuvers. Following this analysis, detailed modeling of each burn and its Various segments was performed to determine its effects on the immediate orbit state. Data gathered from an inclination slew test of the spacecraft and first inclination maneuver uncovered discrepancies in the modeling method that were investigated and resolved. The new modeling techniques were applied and validated during the second spacecraft inclination maneuver. These improvements should position Aqua to successfully complete a series of inclination maneuvers in the fall of 2004. The following paper presents the events and results related

  13. A Study on the Effects of Bee Venom Aqua-Acupuncture on Writhing Reflex

    Directory of Open Access Journals (Sweden)

    Jeong Sun-Hee

    2000-07-01

    Full Text Available Introduction:In spite of the use of Bee Venom aqua-acupuncture in the clinics, the scientific evaluation on effects is not enough. Bee Venom aqua-acupuncture is used according to the stimulation of acupuncture point and the chemical effects of Bee Venom. The aims of this study is to investigate the analgegic effects of the Bee Venom aqua-acupuncture, through the change of writhing reflex Materials and Methods:Pain animal model was used acetic acid method. The changes of writhing reflex of the mice which were derived pain by injecting acetic acid into the abdomen, after stimulating Bee Venom aqua-acupuncture on Chungwan(CV12 and non acupuncture point on the backside were measured. Results:1. It showed that the writhing reflex were appeared on the groups which injected acetic acid only, and saline-acetic acid group(sample I, but not on the group bee venom-saline group(sample II. 2. The change of writhing reflex by Chungwan(CV12 Bee Venom aqua-acupuncture showed significant decrease in the order of Chungwan(CV12 Bee Venom aqua-acupuncture group III(2.5×10-3g/kg, II(2.5×10-4g/kg, and I(2.5×10-5g/kg, compared with control group. There were significant decrease of number of writhing reflex in 5~10, 10~15 and 15~20 minutes intervals of Chung wan(CV12 Bee Venom aqua-acupuncture group I, and in 0~5, 5~10, 10~15 and 15~20 minutes intervals of II and III, compared with control group. 3. The change of writhing reflex by non acupuncture point Bee Venom aqua-acupuncture showed significant decrease in the 0~5 and 5~10 minutes intervals and the total number of writhing reflex in 2.5×10-4g/kg group, compared with control group 4. The effects of writhing reflex of Chungwan(CV12 Bee Venom aqua-acupuncture group showed significant decrease, compared with non acupuncture point Bee Venom aqua-acupuncture group. Conclusion:This study shows that the Bee Venom aqua-acupuncture on Chungwan(CV12 decreases the numbers of writhing reflex. As the

  14. Retrieval of Aerosol Properties from MODIS Terra, MODIS Aqua, and VIIRS SNPP: Calibration Focus

    Science.gov (United States)

    Levy, Robert C.; Mattoo, Shana; Sawyer, Virginia; Kleidman, Richard; Patadia, Falguni; Zhou, Yaping; Gupta, Pawan; Shi, Yingxi; Remer, Lorraine; Holz, Robert

    2016-01-01

    MODIS-DT Collection 6 - Aqua/Terra level 2, 3; entire record processed - "Trending" issues reduced - Still a 15% or 0.02 Terra vs Aqua offset. - Terra/Aqua convergence improved with C6+, but bias remains. - Other calibration efforts yield mixed results. VIIRS-­-DT in development - VIIRS is similar, yet different then MODIS - With 50% wider swath, VIIRS has daily coverage - Ensures algorithm consistency with MODIS. - Currently: 20% NPP vs Aqua offset over ocean. - Only small bias (%) over land (2012-­-2016) - Can VIIRS/MODIS create aerosol CDR? Calibration for MODIS - VIIRS continues to fundamentally important. It's not just Terra, or just Aqua, or just NPP-­-VIIRS, I really want to push synergistic calibration.

  15. Global comparison of soil moisture variations as derived from remote sensing, satellite gravimetry, and hydrological modeling

    Science.gov (United States)

    Abelen, S.; Seitz, F.; Guentner, A.

    2012-04-01

    On local scales soil moisture products are most commonly validated with the help of in-situ measurements, taken at different depth of the soil. On global scales this validation is not possible due to the lack of comprehensive in-situ networks. Therefore global validation is usually done through the inter-comparison of different soil moisture products from space observation systems and hydrological models. From satellite gravimetry the total change in continental water storage (TWS) can be derived, which comprises changes in surface water, ground water, snow water and soil moisture. The compartment soil moisture serves as interface between precipitation (one main driver of the hydrological cycle) and the compartment groundwater. Furthermore it covers the entire continental area in contrast to surface water, which rather appears in point-like (lakes) or line-like (rivers) features. Therefore total continental water storage is an independently derived global data set, which can be related to soil moisture variations. This study focuses on the comparison of conventional soil moisture products from satellite remote sensing and hydrological models in combination with information on total water storage as derived from the satellite gravimetry mission GRACE. The remote sensing products stem from the passive sensors AMSR-E onboard Aqua (NASA) and the active sensor ASCAT onboard MetOp (EUMETSAT). The hydrological model used is the WaterGAP Global Hydrology Model (WGHM). First the two remote sensing soil moisture products from AMSR-E and ASCAT are compared on daily scale, whereby the soil water index (SWI) is applied to both data sets. Then all four data sets are compared in monthly time intervals. To make the soil moisture products compatible with GRACE they first have to be expressed in spherical harmonics and smoothed accordingly (e.g. by a 300km Gaussian filter). Then they will be expressed on a 1° global grid. Afterwards the spatial and temporal agreement between all

  16. [Study of the microwave emissivity characteristics over different land cover types].

    Science.gov (United States)

    Zhang, Yong-Pan; Jiang, Ling-Mei; Qiu, Yu-Bao; Wu, Sheng-Li; Shi, Jian-Cheng; Zhang, Li-Xin

    2010-06-01

    The microwave emissivity over land is very important for describing the characteristics of the lands, and it is also a key factor for retrieving the parameters of land and atmosphere. Different land covers have their emission behavior as a function of structure, water content, and surface roughness. In the present study the global land surface emissivities were calculated using six month (June, 2003-August, 2003, Dec, 2003-Feb, 2004) AMSR-E L2A brightness temperature, MODIS land surface temperature and the layered atmosphere temperature, and humidity and pressure profiles data retrieved from MODIS/Aqua under clear sky conditions. With the information of IGBP land cover types, "pure" pixels were used, which are defined when the fraction cover of each land type is larger than 85%. Then, the emissivity of sixteen land covers at different frequencies, polarization and their seasonal variation were analyzed respectively. The results show that the emissivity of vegetation including forests, grasslands and croplands is higher than that over bare soil, and the polarization difference of vegetation is smaller than that of bare soil. In summer, the emissivity of vegetation is relatively stable because it is in bloom, therefore the authors can use it as its emissivity in our microwave emissivity database over different land cover types. Furthermore, snow cover can heavily impact the change in land cover emissivity, especially in winter.

  17. The melting sea ice of Arctic polar cap in the summer solstice month and the role of ocean

    Science.gov (United States)

    Lee, S.; Yi, Y.

    2014-12-01

    The Arctic sea ice is becoming smaller and thinner than climatological standard normal and more fragmented in the early summer. We investigated the widely changing Arctic sea ice using the daily sea ice concentration data. Sea ice data is generated from brightness temperature data derived from the sensors: Defense Meteorological Satellite Program (DMSP)-F13 Special Sensor Microwave/Imagers (SSM/Is), the DMSP-F17 Special Sensor Microwave Imager/Sounder (SSMIS) and the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) instrument on the NASA Earth Observing System (EOS) Aqua satellite. We tried to figure out appearance of arctic sea ice melting region of polar cap from the data of passive microwave sensors. It is hard to explain polar sea ice melting only by atmosphere effects like surface air temperature or wind. Thus, our hypothesis explaining this phenomenon is that the heat from deep undersea in Arctic Ocean ridges and the hydrothermal vents might be contributing to the melting of Arctic sea ice.

  18. [Study of the microwave emissivity characteristics over different land cover types].

    Science.gov (United States)

    Zhang, Yong-Pan; Jiang, Ling-Mei; Qiu, Yu-Bao; Wu, Sheng-Li; Shi, Jian-Cheng; Zhang, Li-Xin

    2010-06-01

    The microwave emissivity over land is very important for describing the characteristics of the lands, and it is also a key factor for retrieving the parameters of land and atmosphere. Different land covers have their emission behavior as a function of structure, water content, and surface roughness. In the present study the global land surface emissivities were calculated using six month (June, 2003-August, 2003, Dec, 2003-Feb, 2004) AMSR-E L2A brightness temperature, MODIS land surface temperature and the layered atmosphere temperature, and humidity and pressure profiles data retrieved from MODIS/Aqua under clear sky conditions. With the information of IGBP land cover types, "pure" pixels were used, which are defined when the fraction cover of each land type is larger than 85%. Then, the emissivity of sixteen land covers at different frequencies, polarization and their seasonal variation were analyzed respectively. The results show that the emissivity of vegetation including forests, grasslands and croplands is higher than that over bare soil, and the polarization difference of vegetation is smaller than that of bare soil. In summer, the emissivity of vegetation is relatively stable because it is in bloom, therefore the authors can use it as its emissivity in our microwave emissivity database over different land cover types. Furthermore, snow cover can heavily impact the change in land cover emissivity, especially in winter. PMID:20707126

  19. The Tropical Water Vapor Feedback Implied by Aqua Observations

    Science.gov (United States)

    Minschwaner, K.; Dessler, A. E.; Sawaengphokhai, P. C.; Laight, P. A.

    2006-12-01

    We investigate the climate feedback by water vapor in the middle and upper troposphere of the tropics using data from Earth Observing System instruments on the Aqua satellite. The measured water vapor and sea surface temperatures are obtained from AIRS (Atmospheric Infrared Sounder), and outgoing longwave fluxes from CERES (Clouds and Earth's Radiant Energy System). These data are used to quantify any response in tropical mean water vapor to changes in sea surface temperatures. We focus on the effect of variations in both tropical mean sea surface temperature and on variability confined to regions of active convection. Results are compared to feedback estimates based on previous measurements from UARS MLS, as well as the water vapor feedback predicted by global climate model simulations as part of the IPCC AR4 analysis.

  20. Kinerja Saham PT Aqua Golden Mississippi Tbk. Setelah Pembatalan Go Private dan Estimasi Harga Saham Aqua Tahun 2010

    Directory of Open Access Journals (Sweden)

    Indah Wandita Putri

    2010-11-01

    Full Text Available PT Aqua Golden Mississippi is a company that plans to go private, but until today have not obtained approval from the shareholders. Failure may be caused from several things: the company offer price is too small, no quorum, shares held is still profitable for shareholders, and other factors. The existence of the company's plan to go private would affect the performance of the company stock. Stock performance can be analyzed with - average rate of profit, the level of risk, and sensitivity to the stock exchange. The method used in the calculation of stock performance in this paper is the GMR, STDEV, CAPM, and DDM for the calculation of estimated stock price. Through the conducted analysis, investors / shareholders are encouraged to pay attention to the news and information related to go private to be conducted by the company, stock performance, and perform estimate calculations. This is to find out what the right decision for private investors. 

  1. Primary Productivity, NASA Aqua MODIS, 4.4 km, Global, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from NASA Aqua MODIS Chl a SST data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific evaluation by professional...

  2. Debris Likelihood, based on GhostNet, NASA Aqua MODIS, and GOES Imager, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Debris Likelihood Index (Estimated) is calculated from GhostNet, NASA Aqua MODIS Chl a and NOAA GOES Imager SST data. THIS IS AN EXPERIMENTAL PRODUCT: intended...

  3. AIRS/Aqua Level 1B HSB geolocated and calibrated brightness temperatures V005

    Data.gov (United States)

    National Aeronautics and Space Administration — The Atmospheric Infrared Sounder (AIRS) is a facility instrument aboard the second Earth Observing System (EOS) polar-orbiting platform, EOS Aqua. In combination...

  4. Diffuse Attenuation Coef. K490, Aqua MODIS, NPP, 0.125 degrees, Gulf of Mexico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NASA distributes Diffuse Attenuation Coefficient at 490 nm Wavelength data from NASA's Aqua satellite. Measurements are gathered by the Moderate Resolution Imaging...

  5. Chlorophyll-a, Aqua MODIS, NPP, 0.0125 degrees, Gulf of Mexico, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  6. SST, Aqua MODIS, NPP, 0.025 degrees, Pacific Ocean, Daytime

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch provides SST data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging Spectroradiometer (MODIS) carried aboard...

  7. Diffuse Attenuation Coef. K490, Aqua MODIS, NPP, 0.05 degrees, Global, Science Quality

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NASA distributes Diffuse Attenuation Coefficient at 490 nm Wavelength data from NASA's Aqua satellite. Measurements are gathered by the Moderate Resolution Imaging...

  8. SST, Aqua MODIS, NPP, 0.0125 degrees, Gulf of Mexico, Night time (4 microns)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch provides SST data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging Spectroradiometer (MODIS) carried aboard...

  9. Chlorophyll-a, Aqua MODIS, OSU DB, 0.0125 degrees, West US

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua satellite. Measurements are gathered by the Moderate Resolution Imaging...

  10. Chlorophyll-a, Aqua MODIS, NPP, 0.0125 degrees, West US, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  11. Chlorophyll-a, Aqua MODIS, NPP, 0.025 degrees, Pacific Ocean, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  12. Chlorophyll-a, Aqua MODIS, NPP, 0.0125 degrees, East US, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  13. SST, Aqua MODIS, NPP, 0.0125 degrees, East US, Day and Night

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch provides SST data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging Spectroradiometer (MODIS) carried aboard...

  14. Global NOAA CoastWatch Chlorophyll Frontal Product from MODIS/Aqua (NCEI Accession 0110333)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — MODIS/Aqua chlorophyll frontal products: the NOAA Okeanos operational production system produces near real-time chlorophyll frontal products (magnitude and...

  15. Diffuse Attenuation Coef. K490, Aqua MODIS, 0.125 degrees, Indonesia

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — OSU distributes Diffuse Attenuation Coefficient at 490 nm Wavelength data from NASA's Aqua satellite. Measurements are gathered by the Moderate Resolution Imaging...

  16. Chlorophyll-a, Aqua MODIS, NPP, 0.0125 degrees, Indonesia

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  17. EOS Aqua Mission Status at Earth Science Constellation MOWG Meeting @ LASP April 13, 2016

    Science.gov (United States)

    Guit, William J.

    2016-01-01

    This presentation reflects the EOS Aqua mission status, spacecraft subsystem summary, recent and planned activities, inclination adjust maneuvers, propellant usage and lifetime estimate, orbital maintenance maneuvers, conjunction assessment high interest events, ground track error, spacecraft orbital parameters trends and predictions.

  18. Chlorophyll-a, Aqua MODIS, NPP, 0.05 degrees, Global, Science Quality

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration data from NASA's Aqua Spacecraft. Measurements are gathered by the Moderate Resolution Imaging...

  19. Intercomparison of column aerosol optical depths from CALIPSO and MODIS-Aqua

    OpenAIRE

    Kittaka, C.; Winker, D. M.; M. A. Vaughan; Omar, A.; Remer, L. A.

    2011-01-01

    The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) is carried on the CALIPSO satellite and has acquired global aerosol profiles since June 2006. CALIPSO is flown in formation with the Aqua satellite as part of the A-train satellite constellation, so that a large number of coincident aerosol observations are available from CALIOP and the MODIS-Aqua instrument. This study compares column aerosol optical depth at 0.532 μm derived from CALIOP aerosol profiles with MO...

  20. The Effect of Deep Water Aqua Treadmill Training on the Plasma Biochemical Parameters of Show Jumpers

    Directory of Open Access Journals (Sweden)

    Anikó Vincze

    2013-09-01

    Full Text Available Aqua treadmill is mainly used for rehabilitation purposes, but research indicates that this equipment could be used for training as well. The few studies performed with aqua treadmill mainly followed lactate and heart rate changes. Therefore, the aim of this study was to test the effect of high water treadmill training on several blood parameters and on the correlations between them. Eight similarly trained Standardbred show jumper horse competing at the same level were selected with age between 6 to 11 years. The horses were subjected to a one week standardized exercise test which included normal training, training with show jumping and aqua treadmill training. The aqua treadmill training consisted of a 10 min walk (filling up, 4.5 km/h, 30 min trot (13 km/h and 4 min walk (emptying, 4.5 km/h. Blood samples were taken from the jugular vein before aqua training, at the completion of each work bout, after drying and after one and two hour rest. Blood plasma were separated and lactate, LDH, CK, AST, glucose, cholesterol, triglyceride, total-bilirubin and cortisol level were determined. In conclusion plasma lactate response itself does not reflect correctly the intensity of workload in high water level aqua training, therefore measurement of several blood parameters is advisable. Further studies needed to understand the relationship of metabolic processes altered due to the effect of partial water submersion.

  1. Microwave emissivity of fresh water ice--Lake ice and Antarctic ice pack--Radiative transfer simulations versus satellite radiances

    CERN Document Server

    Mills, Peter

    2012-01-01

    Microwave emissivity models of sea ice are poorly validated empirically. Typical validation studies involve using averaged or stereotyped profiles of ice parameters against averaged radiance measurements. Measurement sites are rarely matched and even less often point-by-point. Because of saline content, complex permittivity of sea ice is highly variable and difficult to predict. Therefore, to check the validity of a typical, plane-parallel, radiative-transfer-based ice emissivity model, we apply it to fresh water ice instead of salt-water ice. Radiance simulations for lake ice are compared with measurements over Lake Superior from the Advanced Microwave Scanning Radiometer on EOS (AMSR-E). AMSR-E measurements are also collected over Antarctic icepack. For each pixel, a thermodynamic model is driven by four years of European Center for Medium Range Weather Forecasts (ECMWF) reanalysis data and the resulting temperature profiles used to drive the emissivity model. The results suggest that the relatively simple ...

  2. Improved Prediction of Quasi-Global Vegetation Conditions Using Remotely-Sensed Surface Soil Moisture

    Science.gov (United States)

    Bolten, John; Crow, Wade

    2012-01-01

    The added value of satellite-based surface soil moisture retrievals for agricultural drought monitoring is assessed by calculating the lagged rank correlation between remotely-sensed vegetation indices (VI) and soil moisture estimates obtained both before and after the assimilation of surface soil moisture retrievals derived from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) into a soil water balance model. Higher soil moisture/VI lag correlations imply an enhanced ability to predict future vegetation conditions using estimates of current soil moisture. Results demonstrate that the assimilation of AMSR-E surface soil moisture retrievals substantially improve the performance of a global drought monitoring system - particularly in sparsely-instrumented areas of the world where high-quality rainfall observations are unavailable.

  3. Acoustic Modeling for Aqua Ventus I off Monhegan Island, ME

    Energy Technology Data Exchange (ETDEWEB)

    Whiting, Jonathan M.; Hanna, Luke A.; DeChello, Nicole L.; Copping, Andrea E.

    2013-10-31

    The DeepCwind consortium, led by the University of Maine, was awarded funding under the US Department of Energy’s Offshore Wind Advanced Technology Demonstration Program to develop two floating offshore wind turbines in the Gulf of Maine equipped with Goldwind 6 MW direct drive turbines, as the Aqua Ventus I project. The Goldwind turbines have a hub height of 100 m. The turbines will be deployed in Maine State waters, approximately 2.9 miles off Monhegan Island; Monhegan Island is located roughly 10 miles off the coast of Maine. In order to site and permit the offshore turbines, the acoustic output must be evaluated to ensure that the sound will not disturb residents on Monhegan Island, nor input sufficient sound levels into the nearby ocean to disturb marine mammals. This initial assessment of the acoustic output focuses on the sound of the turbines in air by modeling the assumed sound source level, applying a sound propagation model, and taking into account the distance from shore.

  4. Multi-component removal in flue gas by aqua ammonia

    Science.gov (United States)

    Yeh, James T.; Pennline, Henry W.

    2007-08-14

    A new method for the removal of environmental compounds from gaseous streams, in particular, flue gas streams. The new method involves first oxidizing some or all of the acid anhydrides contained in the gas stream such as sulfur dioxide (SO.sub.2) and nitric oxide (NO) and nitrous oxide (N.sub.2O) to sulfur trioxide (SO.sub.3) and nitrogen dioxide (NO.sub.2). The gas stream is subsequently treated with aqua ammonia or ammonium hydroxide which captures the compounds via chemical absorption through acid-base or neutralization reactions. The products of the reactions can be collected as slurries, dewatered, and dried for use as fertilizers, or once the slurries have been dewatered, used directly as fertilizers. The ammonium hydroxide can be regenerated and recycled for use via thermal decomposition of ammonium bicarbonate, one of the products formed. There are alternative embodiments which entail stoichiometric scrubbing of nitrogen oxides and sulfur oxides with subsequent separate scrubbing of carbon dioxide.

  5. Safety dose of three commercially used growth promoters:nuricell-aqua, hepaprotect-aqua and rapid-grow on growth and survival of Thai pangas (Pangasianodon hypophthalmus)

    Institute of Scientific and Technical Information of China (English)

    Md Ariful Islam; Md Shaheed Reza; Md Alamgir; Md Khalilur Rahman; Md Kamal; Subhash Chandra Chakraborty

    2014-01-01

    Objective: To optimize the dose of 3 commonly used growth promoters, viz., Nuricell-Aqua (composition: glucomannan complex and mannose polymer), Hepaprotect-Aqua (composition:β-glucan, mannose polymer and essential oil) and Rapid-Grow (composition: organic acid and their salt, β-glucan, mannose oligosaccharide and essential oil), using Thai pangas (Pangasiandon hypophthalmus) as cultured species.Methods:Thai pangas fingerlings with an average length and weight of 11 cm and 10 g were reared under laboratory condition and growth promoters were fed after incorporating them with a test diet at a ratio of 10% of their body weight for a period of 28 d. Estimation of data on growth such as weight gain (g), specific growth rate, survivability (%) test in each aquarium were conducted and data were analyzed using statistical software.Results:After 28 d of feeding with Nutricell-Aqua, 10 mg/(20 g feed·day), which was the dose recommended by the manufacturer, was found better. When Hepaprotect-Aqua and Rapid-Grow were employed, performance was found to be better with the dose of 60 mg/(20 g feed·day) which was 1.5 times higher than the dose recommended by the corresponding manufacturer.Conclusions:These results suggest that chemicals and feed additives marketed in Bangladesh Fish Feed Market need further testing under Bangladesh climatic condition before being marketed.

  6. Global observations of quasi-zonal bands in microwave sea surface temperature

    OpenAIRE

    Buckingham, C.E.; Cornillon, P.C.; Schloesser, F.; Obenour, K.M.

    2014-01-01

    Global observations of quasi-zonal jet-like structures have recently been reported in estimates of upper ocean circulation. To date, these observations have come primarily from float-derived and altimeter-derived estimates of zonal velocity. Here, we explore the existence of similar structures in the ocean using satellite-derived estimates of sea surface temperature (SST) from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E). Applying an ocean front detection...

  7. Spatio-Temporal Change of Snow Cover and Its Response to Climate over the Tibetan Plateau Based on an Improved Daily Cloud-Free Snow Cover Product

    OpenAIRE

    Wei Wang; Xiaodong Huang; Jie Deng; Hongjie Xie; Tiangang Liang

    2014-01-01

    Using new, daily cloud-free snow-cover products, this study examines snow cover dynamics and their response to climate change. The results demonstrate that the daily cloud-free snow-cover products not only posses the advantages of the AMSR-E (unaffected by weather conditions) and MODIS (relatively higher resolution) products, but are also characterized by high snow and overall classification accuracies (~85% and ~98%, respectively), substantially greater than those of the existing daily snow...

  8. Evaluation of satellite soil moisture products over Norway using ground-based observations

    Science.gov (United States)

    Griesfeller, A.; Lahoz, W. A.; Jeu, R. A. M. de; Dorigo, W.; Haugen, L. E.; Svendby, T. M.; Wagner, W.

    2016-03-01

    In this study we evaluate satellite soil moisture products from the advanced SCATterometer (ASCAT) and the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) over Norway using ground-based observations from the Norwegian water resources and energy directorate. The ASCAT data are produced using the change detection approach of Wagner et al. (1999), and the AMSR-E data are produced using the VUA-NASA algorithm (Owe et al., 2001, 2008). Although satellite and ground-based soil moisture data for Norway have been available for several years, hitherto, such an evaluation has not been performed. This is partly because satellite measurements of soil moisture over Norway are complicated owing to the presence of snow, ice, water bodies, orography, rocks, and a very high coastline-to-area ratio. This work extends the European areas over which satellite soil moisture is validated to the Nordic regions. Owing to the challenging conditions for soil moisture measurements over Norway, the work described in this paper provides a stringent test of the capabilities of satellite sensors to measure soil moisture remotely. We show that the satellite and in situ data agree well, with averaged correlation (R) values of 0.72 and 0.68 for ASCAT descending and ascending data vs in situ data, and 0.64 and 0.52 for AMSR-E descending and ascending data vs in situ data for the summer/autumn season (1 June-15 October), over a period of 3 years (2009-2011). This level of agreement indicates that, generally, the ASCAT and AMSR-E soil moisture products over Norway have high quality, and would be useful for various applications, including land surface monitoring, weather forecasting, hydrological modelling, and climate studies. The increasing emphasis on coupled approaches to study the earth system, including the interactions between the land surface and the atmosphere, will benefit from the availability of validated and improved soil moisture satellite datasets, including those

  9. Assessment of the consistency among global microwave land surface emissivity products

    OpenAIRE

    H. Norouzi; Temimi, M.; Prigent, C.; Turk, J.; Khanbilvardi, R.; Y. Tian; F. A. Furuzawa; Masunaga, H.

    2015-01-01

    The goal of this work is to intercompare four global land surface emissivity products over various land-cover conditions to assess their consistency. The intercompared land emissivity products were generated over a 5-year period (2003–2007) using observations from the Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E), the Special Sensor Microwave Imager (SSM/I), the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), and WindSat. First, ...

  10. Developing an improved soil moisture dataset by blending passive and active microwave satellite-based retrievals

    Directory of Open Access Journals (Sweden)

    Y. Y. Liu

    2010-09-01

    Full Text Available Combining information derived from satellite-based passive and active microwave sensors has the potential to offer improved retrievals of surface soil moisture variations at global scales. Here we propose a technique to take advantage of retrieval characteristics of passive (AMSR-E and active (ASCAT microwave satellite estimates over sparse-to-moderately vegetated areas to obtain an improved soil moisture product. To do this, absolute soil moisture values from AMSR-E and relative soil moisture derived from ASCAT are rescaled against a reference land surface model date set using a cumulative distribution function (CDF matching approach. While this technique imposes the bias of the reference to the rescaled satellite products, it adjusts both satellite products to the same range and almost preserves the correlation between satellite products and in situ measurements. Comparisons with in situ data demonstrated that over the regions where the correlation coefficient between rescaled AMSR-E and ASCAT is above 0.65 (hereafter referred to as transitional regions, merging the different satellite products together increases the number of observations while minimally changing the accuracy of soil moisture retrievals. These transitional regions also delineate the boundary between sparsely and moderately vegetated regions where rescaled AMSR-E and ASCAT are respectively used in the merged product. Thus the merged product carries the advantages of better spatial coverage overall and increased number of observations particularly for the transitional regions. The combination approach developed in this study has the potential to be applied to existing microwave satellites as well as to new microwave missions. Accordingly, a long-term global soil moisture dataset can be developed and extended, enhancing basic understanding of the role of soil moisture in the water, energy and carbon cycles.

  11. Influence of cracking clays on satellite observed and model simulated soil moisture

    Directory of Open Access Journals (Sweden)

    Y. Y. Liu

    2010-02-01

    Full Text Available Vertisols are clay soils that are common in the monsoonal and dry warm regions of the world. A defining feature of these soils is the development of shrinking cracks during dry periods, the effects of which are not described in land surface models nor considered in the surface soil moisture estimation from passive microwave satellite observations. To investigate the influence of this process we compared the soil moisture (θ in m3 m−3 from AMSR-E observations and the Community Land Model (CLM simulations over vertisols across mainland Australia. Both products agree reasonably well during wet seasons. However, during dry periods, AMSR-E θ falls below values for surrounding non-clays, while CLM simulations are higher. The impacts of soil property used in the AMSR-E algorithm, vegetation density and rainfall patterns were investigated, but do not explain the observed θ patterns. Analysis of the retrieval model suggests that the most likely reason for the low AMSR-E θ is the increase in soil porosity and surface roughness through cracking. CLM does not consider the behavior of cracking clay, including the further loss of moisture from soil and extremely high infiltration rates that would occur when cracks develop. Analyses show that the corresponding water fluxes can be different when cracks occur and therefore modeled evaporation, surface temperature, surface runoff and groundwater recharge should be interpreted with caution. Introducing temporally dynamic roughness and soil porosity into retrieval algorithms and adding a "cracking clay" module into models, respectively, may improve the representation of vertisol hydrology.

  12. Inter-calibrating, Multi-instrument Microwave Ocean Data Records over Three Decades

    Science.gov (United States)

    Smith, D. K.; Wentz, F. J.

    2015-12-01

    Satellite microwave radiometers have been in continuous operation since 1987. When inter-calibrated and consistently processed, the data from a series of DMSP SSM/I and SSMIS sensors, TRMM TMI, Coriolis WindSat, Aqua AMSR-E, GCOM-W1 AMSR2, and GPM GMI collectively result in a long-term high-quality ocean data set of surface winds, atmospheric water vapor, cloud liquid water content, rain rate, and for some instruments, sea surface temperature and wind direction. Slight variations in frequencies, design and satellite orbits stress the need for carefully implementing an inter-calibration method, so as not to introduce trends or jumps when new instruments begin or when old instruments drift and/or die. The authors have developed a robust inter-calibration method using a published, well-developed and validated radiative transfer model (RTM) as the calibration standard. Most of the sensor data for this nearly 30-year period are available as the Version-7 RTM standard. The GMI sensor, recently launched in 2014, has strict calibration accuracy requirements and was built to have greater precision than any previous microwave sensor. We have utilized the dual calibration and non-linearity-measurement systems built into GMI to improve the RTM, which is now Version-8. In this talk we will present an overview of our calibration procedures and outline the steps required to produce climate quality earth data records. We also intend to present the latest validation results and provide information on recent changes in distribution, format, and availability for these already-popular data products.

  13. Using a Support Vector Machine and a Land Surface Model to Estimate Large-Scale Passive Microwave Temperatures over Snow-Covered Land in North America

    Science.gov (United States)

    Forman, Barton A.; Reichle, Rolf Helmut

    2014-01-01

    A support vector machine (SVM), a machine learning technique developed from statistical learning theory, is employed for the purpose of estimating passive microwave (PMW) brightness temperatures over snow-covered land in North America as observed by the Advanced Microwave Scanning Radiometer (AMSR-E) satellite sensor. The capability of the trained SVM is compared relative to the artificial neural network (ANN) estimates originally presented in [14]. The results suggest the SVM outperforms the ANN at 10.65 GHz, 18.7 GHz, and 36.5 GHz for both vertically and horizontally-polarized PMW radiation. When compared against daily AMSR-E measurements not used during the training procedure and subsequently averaged across the North American domain over the 9-year study period, the root mean squared error in the SVM output is 8 K or less while the anomaly correlation coefficient is 0.7 or greater. When compared relative to the results from the ANN at any of the six frequency and polarization combinations tested, the root mean squared error was reduced by more than 18 percent while the anomaly correlation coefficient was increased by more than 52 percent. Further, the temporal and spatial variability in the modeled brightness temperatures via the SVM more closely agrees with that found in the original AMSR-E measurements. These findings suggest the SVM is a superior alternative to the ANN for eventual use as a measurement operator within a data assimilation framework.

  14. Estimating Root Mean Square Errors in Remotely Sensed Soil Moisture over Continental Scale Domains

    Science.gov (United States)

    Draper, Clara S.; Reichle, Rolf; de Jeu, Richard; Naeimi, Vahid; Parinussa, Robert; Wagner, Wolfgang

    2013-01-01

    Root Mean Square Errors (RMSE) in the soil moisture anomaly time series obtained from the Advanced Scatterometer (ASCAT) and the Advanced Microwave Scanning Radiometer (AMSR-E; using the Land Parameter Retrieval Model) are estimated over a continental scale domain centered on North America, using two methods: triple colocation (RMSETC ) and error propagation through the soil moisture retrieval models (RMSEEP ). In the absence of an established consensus for the climatology of soil moisture over large domains, presenting a RMSE in soil moisture units requires that it be specified relative to a selected reference data set. To avoid the complications that arise from the use of a reference, the RMSE is presented as a fraction of the time series standard deviation (fRMSE). For both sensors, the fRMSETC and fRMSEEP show similar spatial patterns of relatively highlow errors, and the mean fRMSE for each land cover class is consistent with expectations. Triple colocation is also shown to be surprisingly robust to representativity differences between the soil moisture data sets used, and it is believed to accurately estimate the fRMSE in the remotely sensed soil moisture anomaly time series. Comparing the ASCAT and AMSR-E fRMSETC shows that both data sets have very similar accuracy across a range of land cover classes, although the AMSR-E accuracy is more directly related to vegetation cover. In general, both data sets have good skill up to moderate vegetation conditions.

  15. Assimilation of space-based passive microwave soil moisture retrievals and the correction for a dynamic open water fraction

    Directory of Open Access Journals (Sweden)

    B. T. Gouweleeuw

    2012-01-01

    Full Text Available The large observation footprint of low-frequency satellite microwave emissions complicates the interpretation of near-surface soil moisture retrievals. While the effect of sub-footprint lateral heterogeneity is relatively limited under unsaturated conditions, open water bodies, if not accounted for, cause a strong positive bias in the satellite-derived soil moisture retrieval. This bias is generally assumed static and associated with large, continental lakes and coastal areas. Temporal changes in the extent of smaller water bodies as small as a few percent of the sensor footprint size, however, can cause significant and dynamic biases. We analysed the influence of such small open water bodies near-surface soil moisture retrieval data from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E for three areas in Oklahoma, USA. Differences between on-ground observations, model estimates and AMSR-E retrievals were compared to dynamic estimates of open water fraction, one retrieved from a global daily record based on higher frequency AMSR-E data and another derived from the Moderate Resolution Imaging Spectroradiometer (MODIS. The comparisons demonstrates that seasonally varying biases of up to 30 vol.% soil water content can be attributed to the presence of relatively small areas (<5% of open water in or near the sensor footprint. These errors need to be addressed, either through elimination or accurate characterization, if the soil moisture retrievals are to be used effectively in a data assimilation scheme.

  16. Evaluation of satellite-based and reanalysis soil moisture products using ground-based measurements

    Science.gov (United States)

    Peng, Jian; Niesel, Jonathan; Loew, Alexander; Zhang, Shiqiang; Wang, Jie

    2016-04-01

    Long-term global satellite-based and reanalysis soil moisture products have been available for several years. Comprehensive evaluation of these products is significant before using them. In this study, in-situ soil moisture measurements from 2008 to 2012 over Southwest China are used to examine the reliability of four satellite-based and one reanalysis soil moisture products. This study evaluates satellite data products (AMSR-E, ASCAT, ESA-CCI, SMOS) and reanalysis data (ERA-Interim) over Southwest China using new in situ soil moisture data. Evaluation of soil moisture absolute values and anomalies shows that all the products except for AMSR-E and SMOS can capture well the temporal dynamics of in-situ soil moisture. The bias and noise in AMSR-E and SMOS are probably due to the severe effects of radio frequency interference (RFI) over this region. In general, the ERA-Interim and CCI SM perform the best compared to the in situ data. The accuracy levels are comparable to validations over other regions worldwide. Therefore, local hydrological applications and water resources managements are expected to benefit a lot from the long-term ERA-Interim and CCI SM soil moisture products.

  17. An Update on Oceanic Precipitation Rate and its Zonal Distribution in Light of Advanced Observations from Space

    Science.gov (United States)

    Behrangi, Ali; Stephens, Graeme; Adler, Robert F.; Huffman, George J.; Lambrigsten, Bjorn; Lebstock, Matthew

    2014-01-01

    This study contributes to the estimation of the global mean and zonal distribution of oceanic precipitation rate using complementary information from advanced precipitation measuring sensors and provides an independent reference to assess current precipitation products. Precipitation estimates from the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and CloudSat cloud profiling radar (CPR) were merged, as the two complementary sensors yield an unprecedented range of sensitivity to quantify rainfall from drizzle through the most intense rates. At higher latitudes, where TRMM PR does not exist, precipitation estimates from Aqua's Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) complemented CloudSat CPR to capture intense precipitation rates. The high sensitivity of CPR allows estimation of snow rate, an important type of precipitation at high latitudes, not directly observed in current merged precipitation products. Using the merged precipitation estimate from the CloudSat, TRMM, and Aqua platforms (this estimate is abbreviated to MCTA), the authors' estimate for 3-yr (2007-09) nearglobal (80degS-80degN) oceanic mean precipitation rate is approx. 2.94mm/day. This new estimate of mean global ocean precipitation is about 9% higher than that of the corresponding Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) value (2.68mm/day) and about 4% higher than that of the Global Precipitation Climatology Project (GPCP; 2.82mm/day). Furthermore, MCTA suggests distinct differences in the zonal distribution of precipitation rate from that depicted in GPCPand CMAP, especially in the Southern Hemisphere.

  18. SPoRT - An End-to-End R2O Activity

    Science.gov (United States)

    Jedlovec, Gary J.

    2009-01-01

    Established in 2002 to demonstrate the weather and forecasting application of real-time EOS measurements, the Short-term Prediction Research and Transition (SPoRT) program has grown to be an end-to-end research to operations activity focused on the use of advanced NASA modeling and data assimilation approaches, nowcasting techniques, and unique high-resolution multispectral observational data applications from EOS satellites to improve short-term weather forecasts on a regional and local scale. SPoRT currently partners with several universities and other government agencies for access to real-time data and products, and works collaboratively with them and operational end users at 13 WFOs to develop and test the new products and capabilities in a "test-bed" mode. The test-bed simulates key aspects of the operational environment without putting constraints on the forecaster workload. Products and capabilities which show utility in the test-bed environment are then transitioned experimentally into the operational environment for further evaluation and assessment. SPoRT focuses on a suite of data and products from MODIS, AMSR-E, and AIRS on the NASA Terra and Aqua satellites, and total lightning measurements from ground-based networks. Some of the observations are assimilated into or used with various versions of the WRF model to provide supplemental forecast guidance to operational end users. SPoRT is enhancing partnerships with NOAA / NESDIS for new product development and data access to exploit the remote sensing capabilities of instruments on the NPOESS satellites to address short term weather forecasting problems. The VIIRS and CrIS instruments on the NPP and follow-on NPOESS satellites provide similar observing capabilities to the MODIS and AIRS instruments on Terra and Aqua. SPoRT will be transitioning existing and new capabilities into the AWIIPS II environment to continue the continuity of its activities.

  19. Performance of the Star Tracker Lightshades on the Earth Observing Satellite (EOS) Aqua

    Science.gov (United States)

    Kenney, Thomas; Schroeder, Michael; Donnelly, Michael; McNally, Mark; Bauer, Frank H. (Technical Monitor)

    2003-01-01

    The TRW built EOS Aqua spacecraft uses two Ball Aerospace CT-602 star trackers to provide attitude updates to the 3-axis, zero momentum, controller. Two months prior to the scheduled launch of Aqua, Ball reported an error in the design of the star tracker lightshades. The lightshades, which had been designed specifically for the EOS Common spacecraft, were not expected to meet the stray light rejection requirements of the mission and thus impact the overall spacecraft pointing performance. What ensued was an effort to characterize the actual performance of the existing shade design, determine what could be done within the physical envelope available, and modify the hardware to meet requirements. Changes were made based on this review activity and Aqua was launched on May 4, 2002. To date the spacecraft is meeting all of its science pointing requirements. Reported here are the lightshade design predictions, test results, and the measured on orbit performance of these shades.

  20. NASA GES DISC DAAC Data Holdings for AIRS/Aqua

    Science.gov (United States)

    Cho, S.; Phelps, C. S.; Sharma, A. K.; Qin, J.

    2002-12-01

    The Atmospheric Infrared Sounder (AIRS) is a high-resolution infrared sounder on the Earth Observing System polar-orbiting platform, EOS Aqua, which was successfully launched on May 4, 2002. AIRS is closely coupled with two microwave instruments, the Advanced Microwave Sounding Unit (AMSU-A) and the Humidity Sounder for Brazil (HSB). The data products from AIRS/AMSU-A/HSB are archived and distributed at the Distributed Active Archive Center (DAAC) located at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). AIRS has 2,378 channels measuring in the infrared range 3.74-15.4 μm and four channels measuring in the visible/near-infrared range 0.4-1.1 μm. AMSU-A is a temperature sounder that primarily provides atmospheric information in the presence of clouds, which is used to correct the AIRS infrared measurements for the effects of the clouds. Likewise, HSB provides information on snow/ice cover, precipitation, and the coarse distribution of moisture in the troposphere. Combined with simultaneous measurements from AIRS, the calibrated brightness temperature from AMSU-A and HSB is used to initialize the atmospheric moisture profile required for the retrieval of the final AIRS geophysical products. The data product suite includes level 1B combined, geolocated and calibrated radiances and will include level 2 final retrievals of surface skin temperature, surface albedo, integrated precipitable water, radiative fluxes, various cloud properties and trace gases (ozone, methane, carbon dioxide, and carbon monoxide). Furthermore, AIRS/AMSU-A/HSB will obtain atmospheric temperature profiles with an accuracy of 1K for every 1 km layer in the troposphere (1K for every 4 km layer in stratosphere) and humidity profiles with an accuracy 20% in 2 km layers from the surface up through the troposphere. Global coverage is obtained twice daily (day and night) on a 1:30 p.m. sun-synchronous orbit from a 705-km altitude. For processing convenience, the data

  1. Stable Failure-Inducing Micro-Silica Aqua Epoxy Bonding Material for Floating Concrete Module Connection

    Directory of Open Access Journals (Sweden)

    Jang-Ho Jay Kim

    2015-11-01

    Full Text Available Many recent studies in the development of floating concrete structures focused on a connection system made of modules. In the connection system, the modules are designed to be attached by pre-stressing (PS while floating on the water, which exposes them to loads on the surface of the water. Therefore, the development of a pre-connection material becomes critical to ensure successful bonding of floating concrete modules. Micro-silica mixed aqua-epoxy (MSAE was developed for this task. To find the proper MSAE mix proportion, 0% to 4% micro-silica was mixed in a standard mixture of aqua-epoxy for material testing. Also, the effect of micro-silica on the viscosity of the aqua epoxy was evaluated by controlling the epoxy silane at proportions of 0%, ±5%, and ±10%. After completion of the performance tests of the MSAE, we evaluated the effect of MSAE in a connected structure. The plain unreinforced concrete module joint specimens applied with MSAE at thicknesses of 5, 10, and 20 mm were prepared to be tested. Finally, we evaluated the performance of MSAE-applied reinforced concrete (RC module specimens connected by PS tendons, and these were compared with those of continuous RC and non-MSAE-applied beams. The results showed that the mix of micro-silica in the aqua-epoxy changed the performance of the aqua-epoxy and the mix ratio of 2% micro-silica gave a stable failure behavior. The flexural capacity of concrete blocks bonded with MSAE changed according to the bond thickness and was better than that of concrete blocks bonded with aqua-epoxy without micro-silica. Even though MSAE insignificantly increases the load-carrying capacity of the attached concrete module structure, the stress concentration reduction effect stabilized the failure of the structure.

  2. Cross-calibration of the Oceansat-2 Ocean Colour Monitor (OCM) with Terra and Aqua MODIS

    Science.gov (United States)

    Angal, Amit; Brinkmann, Jake; Kumar, A. Senthil; Xiong, Xiaoxiong

    2016-05-01

    The Ocean Colour Monitor (OCM) sensor on-board the Oceansat-2 spacecraft has been operational since its launch in September, 2009. The Oceansat 2 OCM primary design goal is to provide continuity to Oceansat-1 OCM to obtain information regarding various ocean-colour variables. OCM acquires Earth scene measurements in eight multi-spectral bands in the range from 402 to 885 nm. The MODIS sensor on the Terra and Aqua spacecraft has been successfully operating for over a decade collecting measurements of the earth's land, ocean surface and atmosphere. The MODIS spectral bands, designed for land and ocean applications, cover the spectral range from 412 to 869 nm. This study focuses on comparing the radiometric calibration stability of OCM using near-simultaneous TOA measurements with Terra and Aqua MODIS acquired over the Libya 4 target. Same-day scene-pairs from all three sensors (OCM, Terra and Aqua MODIS) between August, 2014 and September, 2015 were chosen for this analysis. On a given day, the OCM overpass is approximately an hour after the Terra overpass and an hour before the Aqua overpass. Due to the orbital differences between Terra and Aqua, MODIS images the Libya 4 site at different scan-angles on a given day. Some of the high-gain ocean bands for MODIS tend to saturate while viewing the bright Libya 4 target, but bands 8-10 (412 nm - 486 nm) provide an unsaturated response and are used for comparison with the spectrally similar OCM bands. All the standard corrections such as bidirectional reflectance factor (BRDF), relative spectral response mismatch, and impact for atmospheric water-vapor are applied to obtain the reflectance differences between OCM and the two MODIS instruments. Furthermore, OCM is used as a transfer radiometer to obtain the calibration differences between Terra and Aqua MODIS reflective solar bands.

  3. Diversity of Aphanizomenon flos-aquae (Cyanobacterium) Populations along a Baltic Sea Salinity Gradient

    OpenAIRE

    Laamanen, Maria J.; Forsström, Laura; Sivonen, Kaarina

    2002-01-01

    Colony-forming cyanobacteria of the genus Aphanizomenon form massive blooms in the brackish water of the Baltic Sea during the warmest summer months. There have been recent suggestions claiming that the Baltic Sea Aphanizomenon species may be different from Aphanizomenon flos-aquae found in lakes. In this study, we examined variability in the morphology and 16S-23S rRNA internal transcribed spacer (ITS) sequences of A. flos-aquae populations along a salinity gradient from a string of lakes to...

  4. Aqua[6-carboxylato-N′-(pyridin-2-ylmethylidenepyridine-2-carbohydrazidato]copper(II trihydrate

    Directory of Open Access Journals (Sweden)

    Yu-Min Huang

    2012-06-01

    Full Text Available In the title compound, [Cu(C13H8N4O3(H2O]·3H2O, the complex molecule, except for the aqua ligand, is essentially planar [r.m.s. deviation = 0.034 (2 Å]. The coordination polyhedron of the Cu2+ cation is a square-pyramid, with the aqua ligand at the apex. The compound exhibits a three-dimensional structure, which is is stabilized by O—H...O and O—-H...N hydrogen bonds and π–π interactions [centroid–centroid distance = 2.987 (3 Å].

  5. Poly[μ2-aqua-aqua[μ3-N-butyl-N-(2-hydroxyethyldithiocarbamato-κ3O,O′:S]sodium

    Directory of Open Access Journals (Sweden)

    Muzzaffar A. Bhat

    2016-02-01

    Full Text Available In the title compound, [Na(C7H14NOS2(H2O2]n, the NaI cation is coordinated by five O atoms [Na—O = 2.3142 (11–2.4677 (10 Å] from three aqua and two N-butyl-N-(2-hydroxyethyldithiocarbamate (L ligands and one S atom [Na—S = 3.0074 (6 Å] from a third L ligand in a highly distorted octahedral geometry. Two aqua ligands related by an inversion center bridge two NaI cations, and each L ligand coordinates three NaI cations, leading to a layered arrangement aligned parallel to the bc plane. Intermolecular O—H...S hydrogen bonds are observed in the inner part of each polymeric layer; these are packed along the a axis and held together by weak van der Waals forces.

  6. Aqua-Sim水声信道仿真平台扩展研究%Study on the Extension of Underwater Acoustic Channel with Aqua-Sim

    Institute of Scientific and Technical Information of China (English)

    李丹

    2014-01-01

    The simulator of underwater acoustic channel is one of the most important technologies to ocean network study and has been received extensive attention. Underwater acoustic channel is too complex and volatile to implement the computer simula-tor. For issues of existing studies on models and simulations of underwater acoustic channel, a modified simulator with Aqua-Sim is proposed. In order to build satisfactory experimental environments, the seawater characteristics, such as temperature, salinity, lati-tude, depth and so on, are set with the user interface, and are used as parameters for formulas of sound velocity and background noise. The simulation experiment shows that the effect of improved Aqua-Sim is closer to the actual seawater.%水声信道计算机仿真平台作为海洋网络研究的关键部分已受到广泛关注。由于水声信道具有复杂多变的特性,水声信道的普适性计算机仿真平台研究具有一定难度。本文针对现有水声信道仿真研究存在的问题,对Aqua-Sim水声信道仿真平台进行改进。将海水温度、盐度、纬度和深度等海域环境特征作为仿真平台水下声速和背景噪声计算参数,在仿真实验搭建过程中通过动态参数接口灵活搭建符合实验要求的仿真环境。仿真实验表明,改进后的Aqua-Sim平台仿真效果更加逼近实际海水信道环境。

  7. Polar low monitoring

    Science.gov (United States)

    Bobylev, Leonid; Zabolotskikh, Elizaveta; Mitnik, Leonid

    2010-05-01

    passive microwave data make it possible to retrieve several important atmospheric and oceanic parameters inside the polar lows, such as sea surface wind speed, water vapour content in the atmosphere, total liquid water content in the clouds and others, providing not only qualitative image of a vortex, but also quantitative information about these severe events, constituting a promising tool for their study and monitoring. An approach for detection and tracking of polar lows is developed utilizing the data from two sensors: SSM/I onboard DMSP and Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) onboard Aqua satellite. This approach consists of two stages. At the first stage total atmospheric water vapor fields are retrieved from SSM/I and AMSRE-E measurement data using precise Arctic polar algorithms, developed at NIERSC. These algorithms are applicable over open water. They have high retrieval accuracies under a wide range of environmental conditions. Algorithms are based on numerical simulation of brightness temperatures and their inversion by means of Neural Networks. At the second stage the vortex structures are detected in these fields, polar lows are identified and tracked and some of their parameters are calculated. A few case studies are comprehensively conducted based on SSM/I and AMSRE-E measurements and using other satellite data including visible, infrared and SAR images, QuickScat Scatterometer wind fields, surface analysis maps and re-analysis data, which demonstrated the advantages of satellite passive microwave data usage in the polar low studies.

  8. A Review on the Research and Application of AquaCrop Model%AquaCrop作物模型研究和应用进展

    Institute of Scientific and Technical Information of China (English)

    朱秀芳; 李宜展; 潘耀忠; 史培军

    2014-01-01

    AquaCrop是由国际粮农组织(FAO)开发并向全球免费推广的一款新的作物生长模型,自从2009年发布以来,已经受到各国研究者的重视,而国内对该模型的应用尚处于起步阶段.为国内同仁更深入的了解该模型以及在中国的进一步验证和应用该模型提供有用的背景和参考信息,对模型原理、模型计算方案、模型应用现状和存在问题进行介绍和探讨.众多研究结果证明,AquaCrop模型有很好的模拟精度,可以辅助灌溉管理决策等.AquaCrop作为一个新发展的模型,其适应性还有待进一步验证,研究领域也有待进一步拓宽.

  9. U.S. West Coast MODIS Aqua High Resolution SST Climatology Fields (July 2002 - March 2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This suite of CHLA and SST climatology and anomaly data products are derived from daily, 0.0125 degree x 0.0125 degree, MODIS Aqua CHLA and SST fields that cover...

  10. Structure of O67745_AQUAE, a hypothetical protein from Aquifex aeolicus

    OpenAIRE

    Oganesyan, Vaheh; Adams, Paul D.; Jancarik, Jarmila; Kim, Rosalind; Kim, Sung-Hou

    2007-01-01

    Using single-wavelength anomalous dispersion data obtained from a gold-derivatized crystal, the X-ray crystal structure of the protein 067745_AQUAE from the prokaryotic organism Aquifex aeolicus has been determined to a resolution of 2.0 Å.

  11. 75 FR 16732 - Action Affecting Export Privileges; Aqua-Loop Cooling Towers, Co.

    Science.gov (United States)

    2010-04-02

    ... facilitating or coordinating the export of approximately 174 rolls of hog hair filter media, part number HH6O..., 2004, Aqua-Loop ordered or financed approximately 174 rolls of hog hair filter media, part number... approximately 185 rolls of hog hair filter media, part number HHB6O 130 and valued at approximately...

  12. AquaEnv: an aquatic acid–base modelling environment in R

    NARCIS (Netherlands)

    Hofmann, A.F.; Soetaert, K.E.R.; Middelburg, J.J.; Meysman, F.J.R.

    2010-01-01

    AquaEnv is an integrated software package for aquatic chemical model generation focused on ocean acidification and antropogenic CO2 uptake. However, the package is not restricted to the carbon cycle or the oceans: it calculates, converts, and visualizes information necessary to describe pH, related

  13. Terra and Aqua MODIS Thermal Emissive Bands On-Orbit Calibration and Performance

    Science.gov (United States)

    Xiong, Xiaoxiong; Wu, Aisheng; Wenny, Brian N.; Madhavan, Sriharsha; Wang, Zhipeng; Li, Yonghong; Chen, Na; Barnes, William L.; Salomonson, Vincent V.

    2015-01-01

    Since launch, the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on the Terra and Aqua spacecraft have operated successfully for more than 14 and 12 years, respectively. A key instrument for National Aeronautics and Space Administration Earth Observing System missions, MODIS was designed to make continuous observations for studies of Earth's land, ocean, and atmospheric properties and to extend existing data records from heritage Earth observing sensors. The 16 thermal emissive bands (TEBs) (3.75-14.24 micrometers) are calibrated on orbit using a temperature controlled blackbody (BB). Both Terra and Aqua MODIS BBs have displayed minimal drift over the mission lifetime, and the seasonal variations of the BB temperature are extremely small in Aqua MODIS. The long-term gain and noise equivalent difference in temperature performance of the 160 TEB detectors on both MODIS instruments have been well behaved and generally very stable. Small but noticeable variations of Aqua MODIS bands 33-36 (13.34-14.24 micrometer) response in recent years are primarily due to loss of temperature control margin of its passive cryoradiative cooler. As a result, fixed calibration coefficients, previously used by bands when the BB temperature is above their saturation temperatures, are replaced by the focal-plane-temperature-dependent calibration coefficients. This paper presents an overview of the MODIS TEB calibration, the on-orbit performance, and the challenging issues likely to impact the instruments as they continue operating well past their designed lifetime of six years.

  14. U.S. West Coast MODIS Aqua High Resolution CHLA Anomaly Fields (July 2002 - March 2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This suite of CHLA and SST climatology and anomaly data products are derived from daily, 0.0125 degree x 0.0125 degree, MODIS Aqua CHLA and SST fields that cover...

  15. U.S. West Coast MODIS Aqua High Resolution CHLA Climatology Fields (July 2002 - March 2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This suite of CHLA and SST climatology and anomaly data products are derived from daily, 0.0125 degree x 0.0125 degree, MODIS Aqua CHLA and SST fields that cover...

  16. Evaluation of aqua crop simulation of early season evaporation and water flux in a semiarid environment

    Science.gov (United States)

    The AquaCrop model of crop growth, water use, yield and water use efficiency (WUE) is intended for use by extension personnel, farm and irrigation managers, planners and other less advanced users of simulation models in irrigation planning and scheduling. It could be useful in estimating changes in ...

  17. Simulating yield response to water of Teff (Eragrostis tef) with FAO's AquaCrop model

    NARCIS (Netherlands)

    Araya, A.; Keesstra, S.D.; Stroosnijder, L.

    2010-01-01

    In a semi-arid environment, the main challenge for crop production is water deficit. FAO's AquaCrop model, which simulates yield response to water, has been calibrated to explore alternative water management strategies in teff crop. To calibrate and evaluate this model, we used independent data sets

  18. Validating the FAO AquaCrop model for irrigated and water deficient field maize

    Science.gov (United States)

    Accurate crop development models are important tools in evaluating the effects of water deficits on crop yield or productivity. The FAO AquaCrop model, predicting crop productivity and water requirement under water-limiting conditions, was calibrated and validated for maize (Zea mays L.) using six ...

  19. U.S. West Coast MODIS Aqua High Resolution SST Anomaly Fields (July 2002 - March 2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This suite of CHLA and SST climatology and anomaly data products are derived from daily, 0.0125 degree x 0.0125 degree, MODIS Aqua CHLA and SST fields that cover...

  20. Comparisons of Terra- and Aqua MODIS in band reflectance and vegetation index%Terra MODIS和Aqua MODIS波段反射率及植被指数比较

    Institute of Scientific and Technical Information of China (English)

    王静; 郭铌

    2008-01-01

    对Terra MODIS和Aqua MODIS之间单波段反射率及植被指数进行了比较.结果表明:Terra MODIS和Aqua MODIS单波段反射率及植被指数具有极显著的相关性,植被指数较单波段反射率相关性更高些;Terra MODIS单波段反射率值普遍较Aqua MODIS值低,而植被指数值普遍较Aqua MODIS值高;不同时段Terra MODIS和Aqua MODIS单波段反射率及植被指数间差异不同,植被指数在冬季差异最大,而单波段反射率则在夏秋季差异较大;不同植被类型Terra MODIS和Aqua MODIS间植被指数差异总体规律相似,但单波段反射率间差异较为复杂;草甸、草原无论是单波段反射率还是植被指数,Terra MODIS和AquaMODIS的差异均比其他几种植被类型小,而阔叶林和一年两熟作物则差异相对大些.

  1. Aqua ammonia 15 N obtaining and application with vainness for sugar-cane fertilization

    International Nuclear Information System (INIS)

    Nitrogen compounds marked with the isotope 15 N are continuously being used in agronomic studies and, when associated to the isotopic dilution technique, they constitute an important tool in clarifying the N cycle. At the Centro de Energia Nuclear na Agricultura (CENA/USP), it was obtained ( 15 NH4)2SO4 enhanced at 3,5% of 15 N atoms, by means of the ionic exchange chromatography technique, which made possible to produce aqua ammonia (15 NH3aq). Four repetitions were taken to the aqua ammonia production process to use the nitrogen compound in the field experiment. In each process 150g of ammonium sulfate enhanced at 3,5% of 15 N atoms was used, obtaining 31,0 ± 1,6 g of aqua ammonia on the average (80% yield), with the same enhancement. The incidence of isotopic dilution has not been observed during the procedure, what made the use of such methodology possible. After obtaining the aqua ammonia 15 N through this procedure, it was added to the vinasse (an equivalent to 50 m3 ha-1 ) in doses that corresponded to 70 kg ha-1 of N-NH3aq. The mixture was applied to the sugar-cane straw on the soil's surface, aimed to the crop's fertilization. The compound's isotopic composition was analyzed by means of a spectrometer of masses ANCA-SL Europe Scientific, while the total-N volatilized, by the micro-Kjeldahl. Method. In accordance to the low NH3 (6,4 ± 1,9 kg ha-1 ) volatilization results, it could be concluded that the application of vinasse and aqua ammonia mixture to the straw on the soil's surface was efficient, due to the vinasse's acid character, which allowed the NH3, in presence of the ion H+, to stay in the NH4+ form in solution. (author)

  2. Parameterization of FAO's AquaCrop Model by Integrating a Hydrological Model and Climate Indices

    Science.gov (United States)

    Langhorn, C.; Kienzle, S. W.; Doria, R.; Jiskoot, H.; Cheng, H.

    2014-12-01

    One of the greatest global challenges is to meet growing food demand under rapidly changing climate conditions. Continued global population growth increases the pressure on the agriculture sector to produce enough food to feed the world. In 2013, the province of Alberta, Canada, set a record high for principal field crop production of 34.5 million tonnes (Matejovsky, 2014). AquaCrop, a crop yield and water productivity model developed by the Land and Water Division of the Food and Agriculture Organization of the United Nations (FAO), attempts to balance the accuracy, simplicity and robustness of crop modelling (Steduto et al., 2009). The model is focused on the three components of the soil-plant-atmosphere continuum. AquaCrop is applied in this study for simulating hard red spring wheat and durum wheat yields, and simulated yields are verified against observed yields available from a crop insurer. One of the challenges of crop yield modelling is the selection of a realistic seeding date, which can vary by four to five weeks (end of March to end of April). In order to enable realistic simulation for the historical period 1950-2010 as well the future period 2041-2070, AquaCrop is coupled with the ACRU agro-hydrological modelling system to determine the soil moisture conditions after the spring snow melt, and with a WMO climate index which determines the climatological beginning of the growing season. Therefore, the selection of a realistic seeding data for individual years can be dynamically optimized, based on the combination of the beginning of the climatological growing season and soil moisture status. The results of the coupling of ACRU and calculated climate indices with AquaCrop will be presented to show how improvements of parameterization of the AquaCrop model can be used to simulate wheat yields in Southern Alberta under changing climate conditions.

  3. The Effects of Gardeniae Fructus Aqua-Acupuncture on Liver Injury of Rats Induced by CCI4 (

    Directory of Open Access Journals (Sweden)

    Park, Hee-Soo

    2000-12-01

    Full Text Available This is the study of the effects of Aqua-acupuncture with Gardeniae Fructus on thc recovery of rat's liver which was damaged by 0.3ml/ea of CCI4. Rats were divided into 4 groups; Normal-group(None treated group, Control-group(Not treated after CCI4-intoxicated, Exp. I(Treated with Saline Aqua-acupuncture after CCI4-intoxicated and Exp. ll(Treated with Gardeniae Fructus Aqua-acupuncture after CCI4-intoxicated. Biochemical assays for each serum enzyme activities of AST, ALT, Albumin, LDH, γ-GT, TG and Total cholesterol were performed. The results were summarized as follows: 1. AST activities in serum significantly decreased in the Gardeniae Fructus Aqua-acupuncture treated group after CCI4-intoxicated. In companson with Saline-treated group after CCI4-intoxicated, the Gardeniae Fructus Aqua-acupuncture treated group *The professor of Dept. of Acupuncture & Moxibustion, 2. At T activities in serum significantly decreased in the Gardeniae Fructus Aqua-acupuncture treated group after CCI4-intoxicated. In com pan son with Saline-treated group after CCI4-intoxicated, the Gardeniae Fructus Aqua-acupuncture treated group after CCI4-intoxicated worked effectively to rat's damaged liver. 3. Albumin in serum increased in the Gardeniae Fructus Aqua-acupurkture treated group after CCI4-intoxicated. 4. LDH in serum significantly decreased in the Gardeniae Fructus Aqua-acupuncture treated group after CCI4-intoxicated. In comparison with Saline-treated group after CClcintox icated, the Gardeniae Fructus Aqua acupuncture treated group after CCI4-intoxicated worked highly effectively to rat's damaged liver. 5. γ-GT In serum significantly decreased In the Gardeniae Fructus Aqua-acupuncture trea ted group after CCI4-intoxicated. In compan son with Saline-treated group after CCI4-intoxicated, the Crardeniae Fructus Aqua-acupuncture treated group after CCI4-intoxicated was not recognized significantly. 6. TG in serum significantly decreased in the Gardeniae Fructus

  4. AquaFuel: An example of the emerging new energies and the new methods for their scientific study

    OpenAIRE

    Santilli, Ruggero Maria

    1998-01-01

    In this paper we initiate studies of the emerging new forms of energy by using as a representative example the new combustible gas called AquaFuel, discovered and patented by William H. Richardson, jr., whose rights are now owned by Toups Technology Licensing, Inc. (TTL), of Largo, Florida. In essence, AquaFuel is a new energy converter capable of transforming Carbon and water into a new combustible gas via an electric discharge. We show that AquaFuel can be produced easily, safely and rapidl...

  5. International Earth Science Constellation Mission Operations Working Group September 27-29, 2016 Aqua Spring 2017 IAM Series

    Science.gov (United States)

    Good, Susan M.

    2016-01-01

    This Aqua Spring 2017 IAM Series powerpoint presentation will be presented at the MOWG meeting in Albuquerque, NM. Topics to be discussed are: recap Aqua 2016 IAM campaign maneuver results and post 2016 IAM MLT evolution; current DMU strategy; 2017 IAM campaign dates and planning; Aqua latest lifetime MLT team predictions. Susan Good is a contractor who supports David Tracewell in code 595 therefore this is being routed through 595. Eric Moyer, ESMO Deputy Project Manager-Technical has reviewed and approved this presentation.

  6. Perceived benefits, motives, and barriers to aqua-based exercise among older adults with and without osteoarthritis.

    Science.gov (United States)

    Fisken, Alison; Keogh, Justin W L; Waters, Debra L; Hing, Wayne A

    2015-04-01

    This study aimed to (a) identify factors that motivate older adults to participate in aqua-based exercise; (b) identify potential barriers; and (c) compare perceptions between older adults with and without osteoarthritis (OA). Fifteen adults above 60 years of age participated in one of three focus groups during which they discussed perceived benefits, motives, and barriers to aqua exercise. Pain reduction was considered a major benefit among those with OA, improved health and fitness was a principal benefit for those without OA. All participants felt that the instructor could act as both a motivator and barrier; the most significant barrier was cold changing facilities in winter. With the exception of pain reduction, perceived benefits, motivators, and barriers to aqua-based exercise are similar among older adults with and without OA. A greater understanding of these factors may help us to facilitate older adults with OA to initiate and adhere to aqua-based exercise. PMID:25765822

  7. Dynamic of N fertilizers: urea (15 N) and aqua ammonia (15 N) incorporated to the sugar cane soil. Final report

    International Nuclear Information System (INIS)

    The dynamic of N fertilizers, urea and aqua ammonia, in the soil of sugar cane crops are studied with an emphasis on the horizontal and vertical moving. The nitrogen routing from urea and aqua ammonia sources, by isotopic technique with 15 N in relation to the leaching, volatilization and extraction by the cultivation and residue of N immobilized manure in the soil with sugar cane plantation is also analysed. (C.G.C.)

  8. Mathematical and numerical modeling of the AquaBuOY wave energy converter

    Energy Technology Data Exchange (ETDEWEB)

    Wacher, A.; Nielsen, K.

    2008-12-15

    We have introduced a mathematical model of the vertical dynamics of the AquaBuOY's IPS buoy and hose-pump power take off system. The numerical results obtained proved to be very accurate as compared to real life data of Finavera's fiftieth and tenth scales of the AquaBuOY. The numerical implementation of the model is extremely fast for the regular wave regime and nearly real time for the irregular wave regime, however the results in the irregular wave regime are far more accurate than for regular waves. The model and method have proved to be robust, efficient and accurate however future work is recommended in the time integration scheme used to solve the ordinary differential equations in the irregular wave regime as it would be useful for optimization over many variables to make the numerical integration faster. (Author)

  9. Synthesis, characterization and photochemistry of a new heptamolybdate supported magnesium-aqua coordination complex

    Indian Academy of Sciences (India)

    Savita S Khandolkar; Pallepogu Raghavaiah; Bikshandarkoil R Srinivasan

    2015-09-01

    The synthesis, crystal structure, redox characteristics and photochemistry of a new heptamolyb-date supported magnesium-aqua coordination complex viz. (hmtH)2 [{Mg(H2O)5}2 {Mo7O24}]·3H2O 1 (hmt = hexamethylenetetramine) is reported. The cyclic voltammogram reveals quasireversible redox behaviour while the degradation of rhodamine B (RhB) by 1 under sunlight irradiation indicates its photocatalytic activity. In the crystal structure of 1, two [Mg(H2O)5]2+ units are linked by a 2-bridging bidentate hepta-molybdate ligand resulting in a heptamolybdate supported magnesium-aqua coordinated dianionic complex [{Mg(H2O)5}2 {Mo7O24}]2− charge balanced by two (hmtH)+ cations. The cations, anions and the lattice water molecules are linked by several hydrogen bonding interactions.

  10. AQUA-USERS: AQUAculture USEr Driven Operational Remote Sensing Information Services

    Science.gov (United States)

    Laanen, Marnix; Poser, Kathrin; Peters, Steef; de Reus, Nils; Ghebrehiwot, Semhar; Eleveld, Marieke; Miller, Peter; Groom, Steve; Clements, Oliver; Kurekin, Andrey; Martinez Vicente, Victor; Brotas, Vanda; Sa, Carolina; Couto, Andre; Brito, Ana; Amorim, Ana; Dale, Trine; Sorensen, Kai; Boye Hansen, Lars; Huber, Silvia; Kaas, Hanne; Andersson, Henrik; Icely, John; Fragoso, Bruno

    2015-12-01

    The FP7 project AQUA-USERS provides the aquaculture industry with user-relevant and timely information based on the most up-to-date satellite data and innovative optical in-situ measurements. Its key purpose is to develop an application that brings together satellite information on water quality and temperature with in-situ observations as well as relevant weather prediction and met-ocean data. The application and its underlying database are linked to a decision support system that includes a set of (user-determined) management options. Specific focus is on the development of indicators for aquaculture management including indicators for harmful algae bloom (HAB) events. The methods and services developed within AQUA-USERS are tested by the members of the user board, who represent different geographic areas and aquaculture production systems.

  11. Electronic Crosstalk in Aqua MODIS Long-Wave Infrared Photovoltaic Bands

    Directory of Open Access Journals (Sweden)

    Junqiang Sun

    2016-09-01

    Full Text Available Recent investigations have discovered that Terra MODerate-resolution Imaging Spectroradiometer (MODIS long-wave infrared (LWIR photovoltaic (PV bands, bands 27–30, have strong crosstalk among themselves. The linear model developed to test the electronic crosstalk effect was instrumental in the first discovery of the effect in Terra MODIS band 27, and through subsequent investigations the model and the correction algorithm were tested further and established to be correct. It was shown that the correction algorithm successfully mitigated the anomalous features in the calibration coefficients as well as the severe striping and the long-term drift in the Earth view (EV retrievals for the affected Terra bands. Here, the examination into Aqua MODIS using the established methodology confirms the existence of significant crosstalk contamination in its four LWIR PV, although the finding shows the overall effect to be of lesser degree. The crosstalk effect is characterized and the crosstalk correction coefficients are derived for all four Aqua LWIR PV bands via analysis of signal contamination in the lunar imagery. Sudden changes in the crosstalk contamination are clearly seen, as also in the Terra counterparts in previous investigations. These sudden changes are consistent with the sudden jumps observed in the linear calibration coefficients for many years, thus this latest finding provides an explanation to the long-standing but unexplained anomalies in the calibration coefficients of the four Aqua LWIR bands. It is also shown that the crosstalk contamination for these bands are of similar level for the two MODIS instruments in the early mission that can lead to as much as 2 K increase in brightness temperature for the affected bands, thus demonstrating significant impact on the science results already started at the early going. As Aqua MODIS is a legacy sensor, the crosstalk correction to its LWIR PV bands will be important to remove the impact of

  12. An Overview of Lunar Calibration and Characterization for the EOS Terra and Aqua MODIS

    Science.gov (United States)

    Xiong, X.; Salomonson, V. V.; Sun, J.; Chiang, K.; Xiong, S.; Humphries, S.; Barnes, W.; Guenther, B.

    2004-01-01

    The Moon can be used as a stable source for Earth-observing sensors on-orbit radiometric and spatial stability monitoring in the VIS and NIR spectral regions. It can also serve as a calibration transfer vehicle among multiple sensors. Nearly identical copies of the Moderate Resolution Imaging Spectroradiometer (MODE) have been operating on-board the NASA's Earth Observing System (EOS) Terra and Aqua satellites since their launches in December 1999 and May 2002, respectively. Terra and Aqua MODIS each make observations in 36 spectral bands covering the spectral range from 0.41 to 14.5 microns and are calibrated on-orbit by a set of on-board calibrations (OBCs) including: 1) a solar diffuser (SD), 2) a solar diffuser stability monitor (SDSM), 3) a blackbody (BB), and 4) a spectro-radiometric calibration assembly (SRCA). In addition to fully utilizing the OBCs, the Moon has been used extensively by both Terra and Aqua MODIS to support their on-orbit calibration and characterization. A 4 This paper provides an overview of applications of lunar calibration and characterization from the MODIS perspective, including monitoring radiometric calibration stability for the reflective solar bands (RSBs), tracking changes of the sensors response versus scan-angle (RVS), examining the sensors spatial performance , and characterizing optical leaks and electronic crosstalk among different spectral bands and detectors. On-orbit calibration consistency between the two MODIS instruments is also addressed. Based on the existing on-orbit time series of the Terra and Aqua MODIS lunar observations, the radiometric difference between the two sensors is less than +/-1% for the RSBs. This method provides a powerful means of performing calibration comparisons among Earth-observing sensors and assures consistent data and science products for the long-term studies of climate and environmental changes.

  13. EFFECTS OF AQUA AEROBICS AND FLOOR AEROBICS ON BREATH HOLDING TIME AMONG SCHOOL GIRLS

    OpenAIRE

    P.V. Shelvam; S. Arunadevi

    2013-01-01

    The purpose of the study was to find out the effects of aqua aerobics and floor aerobics on breath holding time among school girls. To achieve this purpose of the study, ninety school girls were selected as subjects who were studied Cornation Higher Secondary School, Sivakasi. The selected subjects were aged between 15 to 17 years. The selected subjects were randomly divided into three groups of 30 subjects each group. Group one acted as experimental group I and group two acted as experimenta...

  14. Paralytic shellfish toxins in the freshwater cyanobacterium Aphanizomenon flos-aquae, isolated from Montargil reservoir, Portugal.

    Science.gov (United States)

    Pereira, P; Onodera, H; Andrinolo, D; Franca, S; Araújo, F; Lagos, N; Oshima, Y

    2000-12-01

    Montargil reservoir, located in a dry flat area in the centre of Portugal, was filled in 1958 to fulfil agricultural, electric and industrial requirements. In May 1996, an intensive bloom of phytoplankton was detected. The algal community was strongly dominated by cyanobacteria with predominance of Aphanizomenon flos-aquae from May to June and Microcystis aeruginosa from July to August. Extracts of samples collected during the bloom period showed high toxicity by mouse bioassay. During the M. aeruginosa predominance period, the toxicity was ascribed to the presence of hepatotoxins, but clear symptoms of paralytic shellfish poison were observed when A. flos-aquae was the dominant species. In order to confirm the production of neurotoxins a strain of A. flos-aquae was isolated and established in culture. In this manuscript, we show the morphological characteristics and confirm paralytic shellfish toxins production by the strain isolated and maintained in culture. Identification of the saxitoxin analogs was achieved using high performance liquid chromatography with postcolumn fluorescence derivatization (HPLC-FLD) and liquid chromatographic mass spectrometry technique (LC-MS). The toxins found in the culture extract were GTX5 (64.5 mol%), neoSTX (23.0 mol%), dcSTX (6.1 mol%), STX (5.4 mol%) and GTX6 (1.1 mol%). This is, to our knowledge, the first report of unambiguous evidence of paralytic shellfish toxins produced by freshwater cyanobacteria in Portugal. The toxin profile is rather different from the previously reported PSP producing A. flos-aquae and demonstrates its diversity in terms of toxin production. PMID:10858510

  15. Simulating yield response of rice to salinity stress with the AquaCrop model.

    Science.gov (United States)

    Mondal, M Shahjahan; Saleh, Abul Fazal M; Razzaque Akanda, Md Abdur; Biswas, Sujit K; Md Moslehuddin, Abu Zofar; Zaman, Sinora; Lazar, Attila N; Clarke, Derek

    2015-06-01

    The FAO AquaCrop model has been widely applied throughout the world to simulate crop responses to deficit water applications. However, its application to saline conditions is not yet reported, though saline soils are common in coastal areas. In this study, we parameterized and tested AquaCrop to simulate rice yield under different salinity regimes. The data and information required in the model were collected through a field experiment at the Bangladesh Agricultural Research Institute, Gazipur. The experiment was conducted with the BRRI Dhan28, a popular boro rice variety in Bangladesh, with five levels of saline water irrigation, three replicates for each level. In addition, field monitoring was carried out at Satkhira in the southwest coastal region of Bangladesh to collect data and information based on farmers' practices and to further validate the model. The results indicated that the AquaCrop model with most of its default parameters could replicate the variation of rice yield with the variation of salinity reasonably well. The root mean square error and mean absolute error of the model yield were only 0.12 t per ha and 0.03 t per ha, respectively. The crop response versus soil salinity stress curve was found to be convex in shape with a lower threshold of 2 dS m(-1), an upper threshold of 10 dS m(-1) and a shape factor of 2.4. As the crop production system in the coastal belt of Bangladesh has become vulnerable to climate induced sea-level rise and the consequent increase in water and soil salinity, the AquaCrop would be a useful tool in assessing the potential impact of these future changes as well as other climatic parameters on rice yield in the coastal region.

  16. Estimation of Daily Sunshine Duration from Terra and Aqua MODIS Data

    OpenAIRE

    Kandirmaz, H. M.; K. Kaba

    2014-01-01

    Some studies have shown that the estimation of global sunshine duration can be done with the help of geostationary satellites because they can record several images of the same location in a day. In this paper, images obtained from the MODIS (Moderate Resolution Imaging Spectroradiometer) sensors of polar orbiting satellites Aqua and Terra were used to estimate daily global sunshine duration for any region in Turkey. A new quadratic correlation between daily mean cloud cover index and relati...

  17. Optimized Merger of Ocean Chlorophyll Algorithms of MODIS-Aqua and VIIRS

    OpenAIRE

    Kahru, M.; Kudela, RM; Anderson, CR; Mitchell, BG

    2015-01-01

    Standard ocean chlorophyll-a (Chla) products from currently operational satellite sensors Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua and Visible Infrared Imager Radiometer Suite (VIIRS) underestimate medium and high in situ Chla concentrations and have approximately 9% bias between each other in the California Current. By using the regional optimization approach of Kahru et al., we minimized the differences between satellite estimates and in situ match-ups as well as between e...

  18. Assessment of diverse algorithms applied on MODIS Aqua and Terra data over land surfaces in Europe

    OpenAIRE

    Glantz, P.; Tesche, M

    2012-01-01

    The aim of the present study is to validate AOT (aerosol optical thickness) and Ångström exponent (α), obtained with the SAER (Satellite AErosol Retrieval) algorithm for MODIS (MODerate resolution Imaging Spectroradiometer) Aqua and Terra calibrated level 1 data (1 km horizontal resolution at ground) and MODIS Collection 5 (c005) standard product retrievals (10 km), against AERONET (AErosol RObotic NETwork) observations over land surfaces in Europe. The three time periods investigated in ...

  19. Inter-comparison of Terra and Aqua MODIS Feflective Solar Bands using Suomi NPP VIIRS

    OpenAIRE

    Blonski, Slawomir; Cao, Changyong; Uprety, Sirish; Shao, Xi

    2013-01-01

    VIIRS (Visible Infrared Imager Radiometer Suite) onboard the Suomi NPP (National Polar-orbiting Partnership) satellite has been acquiring Earth observations for more than a year. During that time, SNO (Simultaneous Nadir Overpass) events have provided many opportunities for inter-comparisons between VIIRS and the MODIS (Moderate Resolution Imaging Spectroradiometer) instruments from the Aqua and Terra satellites. The SNOs have occurred over snow-covered Antarctica, which provided bright surfa...

  20. AquaCrop模型的适用性及应用初探%The Applicability and Application of AquaCrop Model

    Institute of Scientific and Technical Information of China (English)

    李会; 刘钰; 蔡甲冰; 毛晓敏

    2011-01-01

    AquaCrop模型是FAO新推出的以水分为驱动的作物生长模型。为了评价其在华北地区的适用性,于2009-2010年在中国水利水电科学研究院大兴试验站进行了夏玉米水分处理试验,其中2010年的试验数据用于参数率定,2009年的试验教据用于模型验证,并在此基础上对模型参数进行敏感性分析。结果表明,AquaCrop模型能够较好地模拟夏玉米的产量、生物量、冠层覆盖率及土壤水分的动态变化,产量和生物量模拟值和实测值的相对误盖为0%~15.6%,冠层覆盖率和土壤含水率变化过程的模拟值和实测值间相关性的决定系数最小分别为0.959、0.657,均方根误差RMSE最大分别为5.837%、1.873 m3/m3,模型效率指数RE最小分别为0.670、0.956;敏感性分析量示,达到最大冠层覆盖率的日期、冠层开始衰老的日期、田间持水率、凋萎含水率及初始含水率为敏感参数,相对敏感度RS处于0.161 4~0.398 2。说明模型在该区的适用性良好,具有广阔的发展前景。%AquaCrop model driven by water is a new crop simulated model recommend by FAO. In order to evaluate its applicability in North China , this irrigation experiment for summer maize was conducted in two successive year (2009-2010) in Daxing station in north china plain, of which, the measured date in 2010 was used to calibrate the crop parameters, and the other was used to test it. Then the OTA method was a-dopted to analyze sensitivities of the model parameter. The validation results showed that the AquaCrop model could preferably simulate the yield, biomass and the dynamic changes of canopy cover and soil moisture of summer maize. The relative error of simulated yield and biomass is 0%~15. 6%. For simulated the process of canopy cover and soil moisture, the minimum correlation coefficient of determination were 0. 657, 0. 959, the maximum of root mean square error 5. 837%, 1. 873 m3/m3 and the minimum model

  1. Structure of O67745-AQUAE, a hypothetical protein from Aquifex aeolicus

    Energy Technology Data Exchange (ETDEWEB)

    Oganesyan, Vaheh; Adams, Paul D.; Jancarik, Jarmila; Kim, Rosalind; Kim, Sung-Hou, E-mail: shkim@lbl.gov [Berkeley Structural Genomics Center, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2007-05-01

    Using single-wavelength anomalous dispersion data obtained from a gold-derivatized crystal, the X-ray crystal structure of the protein 067745-AQUAE from the prokaryotic organism Aquifex aeolicus has been determined to a resolution of 2.0 Å. Using single-wavelength anomalous dispersion data obtained from a gold-derivatized crystal, the X-ray crystal structure of the protein 067745-AQUAE from the prokaryotic organism Aquifex aeolicus has been determined to a resolution of 2.0 Å. Amino-acid residues 1–371 of the 44 kDa protein were identified by Pfam as an HD domain and a member of the metal-dependent phosphohydrolase superfamily (accession No. PF01966). Although three families from this large and diverse group of enzymatic proteins are represented in the PDB, the structure of 067745-AQUAE reveals a unique fold that is unlike the others and that is likely to represent a new subfamily, further organizing the families and characterizing the proteins. Data are presented that provide the first insights into the structural organization of the proteins within this clan and a distal alternative GDP-binding domain outside the metal-binding active site is proposed.

  2. Structure of O67745-AQUAE, a hypothetical protein from Aquifex aeolicus

    International Nuclear Information System (INIS)

    Using single-wavelength anomalous dispersion data obtained from a gold-derivatized crystal, the X-ray crystal structure of the protein 067745-AQUAE from the prokaryotic organism Aquifex aeolicus has been determined to a resolution of 2.0 Å. Using single-wavelength anomalous dispersion data obtained from a gold-derivatized crystal, the X-ray crystal structure of the protein 067745-AQUAE from the prokaryotic organism Aquifex aeolicus has been determined to a resolution of 2.0 Å. Amino-acid residues 1–371 of the 44 kDa protein were identified by Pfam as an HD domain and a member of the metal-dependent phosphohydrolase superfamily (accession No. PF01966). Although three families from this large and diverse group of enzymatic proteins are represented in the PDB, the structure of 067745-AQUAE reveals a unique fold that is unlike the others and that is likely to represent a new subfamily, further organizing the families and characterizing the proteins. Data are presented that provide the first insights into the structural organization of the proteins within this clan and a distal alternative GDP-binding domain outside the metal-binding active site is proposed

  3. AquaCrop model simulation under different irrigation water and nitrogen strategies.

    Science.gov (United States)

    Khoshravesh, Mojtaba; Mostafazadeh-Fard, Behrouz; Heidarpour, Manouchehr; Kiani, Ali-Reza

    2013-01-01

    On a global scale, irrigated agriculture consumes about 72% of available freshwater resources. Deficit irrigation can be applied in the field to save irrigation water and still lead to acceptable crop production. The AquaCrop model is a simulation model for management of irrigation and nitrogen fertilizer. This model is a new model that is accurate, robust and requires fewer data inputs compared with the other models. The purpose of this study was to simulate canopy cover, grain yield and water use efficiency (WUE) for soybean using the AquaCrop model. A field line source sprinkler irrigation system was conducted under full and deficit irrigation using different nitrogen fertilizer applications during two cropping seasons for soybean at Gorgan province in Iran. The simulation results showed a reasonably accurate prediction of yield, canopy cover and WUE in all cases (error less than 23%). The simulated pattern of canopy progression over time was close to measured values, with Willmott's index of agreement for all the cases being ≥0.95 for different parameters. The AquaCrop model has the ability to simulate the WUE of soybean under different irrigation water and nitrogen applications. This model is a useful tool for managing the crop water productivity.

  4. Spatial and Temporal Distribution of Clouds Observed by MODIS Onboard the Terra and Aqua Satellites

    Science.gov (United States)

    King, Michael D.; Platnick, Steven; Menzel, W. Paul; Ackerman, Steven A.; Hubanks, Paul A.

    2012-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) was developed by NASA and launched aboard the Terra spacecraft on December 18, 1999 and Aqua spacecraft on May 4, 2002. A comprehensive set of remote sensing algorithms for the retrieval of cloud physical and optical properties have enabled over twelve years of continuous observations of cloud properties from Terra and over nine years from Aqua. The archived products from these algorithms include 1 km pixel-level (Level-2) and global gridded Level-3 products. In addition to an extensive cloud mask, products include cloud-top properties (temperature, pressure, effective emissivity), cloud thermodynamic phase, cloud optical and microphysical parameters (optical thickness, effective particle radius, water path), as well as derived statistics. Results include the latitudinal distribution of cloud optical and radiative properties for both liquid water and ice clouds, as well as latitudinal distributions of cloud top pressure and cloud top temperature. MODIS finds the cloud fraction, as derived by the cloud mask, is nearly identical during the day and night, with only modest diurnal variation. Globally, the cloud fraction derived by the MODIS cloud mask is approx.67%, with somewhat more clouds over land during the afternoon and less clouds over ocean in the afternoon, with very little difference in global cloud cover between Terra and Aqua. Overall, cloud fraction over land is approx.55%, with a distinctive seasonal cycle, whereas the ocean cloudiness is much higher, around 72%, with much reduced seasonal variation. Cloud top pressure and temperature have distinct spatial and temporal patterns, and clearly reflect our understanding of the global cloud distribution. High clouds are especially prevalent over the northern hemisphere continents between 30 and 50 . Aqua and Terra have comparable zonal cloud top pressures, with Aqua having somewhat higher clouds (cloud top pressures lower by 100 hPa) over land due to

  5. Assimilation of satellite information in a snowpack model to improve characterization of snow cover for runoff simulation and forecasting

    Directory of Open Access Journals (Sweden)

    L. S. Kuchment

    2009-08-01

    Full Text Available A new technique for constructing spatial fields of snow characteristics for runoff simulation and forecasting is presented. The technique incorporates satellite land surface monitoring data and available ground-based hydrometeorological measurements in a physical based snowpack model. The snowpack model provides simulation of temporal changes of the snow depth, density and water equivalent (SWE, accounting for snow melt, sublimation, refreezing melt water and snow metamorphism processes with a special focus on forest cover effects. The model was first calibrated against available ground-based snow measurements and then was applied to calculate the spatial distribution of snow characteristics using satellite data and interpolated ground-based meteorological data. The remote sensing data used in the model consist of products derived from observations of MODIS and AMSR-E instruments onboard Terra and Aqua satellites. They include daily maps of snow cover, snow water equivalent (SWE, land surface temperature, and weekly maps of surface albedo. Maps of land cover classes and tree cover fraction derived from NOAA AVHRR were used to characterize the vegetation cover. The developed technique was tested over a study area of approximately 200 000 km2 located in the European part of Russia (56° N to 60° N, and 48° E to 54° E. The study area comprises the Vyatka River basin with the catchment area of 124 000 km2. The spatial distributions of SWE, obtained with the coupled model, as well as solely from satellite data were used as the inputs in a physically-based model of runoff generation to simulate runoff hydrographs on the Vyatka river for spring seasons of 2003, 2005. The comparison of simulated hydrographs with the observed ones has shown that suggested procedure gives a higher accuracy of snow cover spatial distribution representation and hydrograph simulations than the direct use of satellite SWE data.

  6. Boundary layer regulation in the southeast Atlantic cloud microphysics during the biomass burning season as seen by the A-train satellite constellation

    Science.gov (United States)

    Painemal, David; Kato, Seiji; Minnis, Patrick

    2014-10-01

    Solar radiation absorption by biomass burning aerosols has a strong warming effect over the southeast Atlantic. Interactions between the overlying smoke aerosols and low-level cloud microphysics and the subsequent albedo perturbation are, however, generally ignored in biomass burning radiative assessments. In this study, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) are combined with Aqua satellite observations from Moderate Resolution Imaging Spectroradiometer (MODIS), Advanced Microwave Scanning Radiometer-EOS (AMSR-E), and Clouds and the Earth's Radiant Energy System (CERES) to assess the effect of variations in the boundary layer height and the separation distance between the cloud and aerosol layers on the cloud microphysics. The merged data analyzed at a daily temporal resolution suggest that overlying smoke aerosols modify cloud properties by decreasing cloud droplet size despite an increase in the cloud liquid water as boundary layer deepens, north of 5°S. These changes are controlled by the proximity of the aerosol layer to the cloud top rather than increases in the column aerosol load. The correlations are unlikely driven by meteorological factors, as three predictors of cloud variability, lower tropospheric stability, surface winds, and mixing ratio suggest that cloud effective radius, cloud top height, and liquid water path should correlate positively. Because cloud effective radius anticorrelates with cloud liquid water over the region with large microphysical changes—north of 5°S—the overall radiative consequence at the top of the atmosphere is a strong albedo susceptibility, equivalent to a 3% albedo increase due to a 10% decrease in cloud effective radius. This albedo enhancement partially offsets the aerosol solar absorption. Our analysis emphasizes the importance of accounting for the indirect effect of smoke aerosols in the cloud microphysics when estimating the radiative impact of the biomass burning at the

  7. 基于水分驱动的 AquaCrop 模型及其研究进展%AquaCrop model based on water-driven principle and its research progress

    Institute of Scientific and Technical Information of China (English)

    张万红; 刘文兆; 王芸

    2014-01-01

    介绍了AquaCrop模型的原理及基本参数,从模型的校验与应用两方面阐述了该模型的研究进展。指出目前仍缺乏实测数据验证AquaCrop模型对蒸发及蒸腾的模拟效果;AquaCrop模型在严重水分及盐分胁迫下模拟结果精度较差;已开展的模拟研究地域范围窄;由于缺少更复杂的生理子模块,AquaCrop模型不能很好解释水分胁迫对光合产物向籽粒运输分配过程的影响。为了提高模型的模拟精度并进一步延伸模型的应用范围,应完善模型水分及盐胁迫模块,并在较广范围内获取丰富的实测数据对模型开展进一步的校验研究。%The theory ,parameters and characteristics of AquaCrop model were introduced and its research progress was reviewed from the viewpoints of validation and application of the model .It was pointed that :the measured data of e-vaporation and transpiration were still lacked for the validation of simulating results of AquaCrop model ;the performance of AquaCrop model was poor under severe water and salt stress conditions ;The locations for model study were not di-verse;Because of lacking of the move complicated plant physiological submodel ,AquaCrop model was not able to account for water stress impact on biomass partitioning into yield .In order to increase the accuracy degree of AquaCrop model and extend its application range ,it is necessary to get abundant data measured for diverse locations and perfect the module of water and salt stress .

  8. Investigation of polar mesocyclones in Arctic Ocean using COSMO-CLM and WRF numerical models and remote sensing data

    Science.gov (United States)

    Varentsov, Mikhail; Verezemskaya, Polina; Baranyuk, Anastasia; Zabolotskikh, Elizaveta; Repina, Irina

    2015-04-01

    Polar lows (PL), high latitude marine mesoscale cyclones, are an enigmatic atmospheric phenomenon, which could result in windstorm damage of shipping and infrastructure in high latitudes. Because of their small spatial scales, short life times and their tendency to develop in remote data sparse regions (Zahn, Strorch, 2008), our knowledge of their behavior and climatology lags behind that of synoptic-scale cyclones. In case of continuing global warming (IPCC, 2013) and prospects of the intensification of economic activity and marine traffic in Arctic region, the problem of relevant simulation of this phenomenon by numerical models of the atmosphere, which could be used for weather and climate prediction, is especially important. The focus of this paper is researching the ability to simulate polar lows by two modern nonhydrostatic mesoscale numerical models, driven by realistic lateral boundary conditions from ERA-Interim reanalysis: regional climate model COSMO-CLM (Böhm et. al., 2009) and weather prediction and research model (WRF). Fields of wind, pressure and cloudiness, simulated by models, were compared with remote sensing data and ground meteorological observations for several cases, when polar lows were observed, in Norwegian, Kara and Laptev seas. Several types of satellite data were used: atmospheric water vapor, cloud liquid water content and surface wind fields were resampled by examining AMSR-E and AMSR-2 microwave radiometer data (MODIS Aqua, GCOM-W1), and wind fields were additionally extracted from QuickSCAT scatterometer. Infrared and visible pictures of cloud cover were obtained from MODIS (Aqua). Completed comparison shown that COSMO-CLM and WRF models could successfully reproduce evolution of polar lows and their most important characteristics such as size and wind speed in short experiments with WRF model and longer (up to half-year) experiments with COSMO-CLM model. Improvement of the quality of polar lows reproduction by these models in

  9. The Closed Aquatic System AquaHab® as part of a CELSS for Exploration, Space and Earth Application

    Science.gov (United States)

    Slenzka, Klaus

    AquaHab R is a small, self-sustaining closed microcosm, based on the former space shuttle payload C.E.B.A.S. (Closed Equilibrated Biological Aquatic System). AquaHab R contains on laboratory scale within 8 liters of water volume different groups of organisms (fish, snails, amphipods, plants). During the last years, it was developed to a system for the risk assessment of chemicals as well as an early warning tool for air and water contamination, major concerns during long-term stays in closed habitats for example on Earth's subsurface (deep sea) or later on the Moon or Mars. AquaHab R is now enhanced developed for exploratory missions having implemented an algae reactor system for biomass production etc.. During first tests, the transport of oxygen from the algae reactor into the AquaHab R was demonstrated successfully. In the common AquaHab R - bioreactor system, the different subsystems will serve for several tasks. In the AquaHab R - tank, the removal of waste water (mainly nutrients) as well as the production of some higher plants and fish as food source will be most beneficial; additionally the AquaHab R -tank is supporting astronauts psychological health recovery (home aquaria effect, taking care for pets). The beneficially output of the algae reactors will e.g. be the increased delivery of oxygen and metabolic products with application potential for humans (as e.g. vitamins, drug like acting substances) as well as being a food source in general and also the removal of carbon dioxide. Furthermore, specialized algae can also serve as early warning tool, as all the organisms in the AquaHab R do, or producing energy equivalents. The different subsystems will interact with each other to treat the products of humans being in the closed habitat in the most effective way. This new life support subsystem will be bioregenerative and sustainable in the meaning, that no material transport into the system is needed, and non-usable and maybe toxic end products won‘t be

  10. Effects of Hominis Placenta Aqua-acupuncture on Kidney and Liver Intoxicated by HgCI2 in Rats

    Directory of Open Access Journals (Sweden)

    Lee, Sang-Keel

    2000-12-01

    Full Text Available Objective: This study was perfomled to examine the therapeutic effect of aqua-acupuncture solution of Hominis Placenta(HP on kidney and liver intoxicated by HgCl2 in rats. Methods: 10% and 25% HP aqua-acupuncture were carried out everyday for 8 days on corresponding bilateral loci of Shinsu(BL23 and Kansu(BL18, respectively, after mercuric chloride intoxication in rats. Thereafter BUN, creatinine, GOT, GPT, ALP, -GT, albumin and total bilirubin were measured before intoxication, and at the 4th and the 8th experimental day. Histopathological and immunochemical observation were also carried out. Results: 1. It showed significant decreases of BUN in the group of 10% HP aqua-acupuncture into Shinsu on the 4th experimental day as compared with the control group. 2. It showed significant decreases of creatinine in the group of 10% HP aqua-acupuncture into Shinsu on the 4th and the 8th experimental days as compared with the control group. 3. There were not any significant changes of GOT, GPT, ALP, γ-GT, albumin and total bilirubin in the HP aqua-acupuncture groups compared with the control group. 4. By the histopathological observations on kidney under a light microscope, all the 10% and 25% HP aqua-acupuncture into Shinsu showed the preventive effect on tubulo-interstitial necrosis and muItifocal calcification in tubular lumen respectively compared with the control group. 5. By the histopathological observations on liver under a light mIcroscope, the groups 10% and 25% HP aqua-acupuncture into Kansu did not show any significant changes in the liver compared with the control group. 6. By the immunochemical analysis of heat shock protein(hsp and glucose-regulated protein(grp in rat renal cortex, the expressions of hsp70 and grp78 were decreased in the and HP aqua-acupuncture into Shinsu respectively compared with the control group. Conclusion: These results suggest that Hominis Placenta aqua-acupuncture have an effect on prevention and protection of

  11. AquaFuel An example of the emerging new energies and the new methods for their scientific study

    CERN Document Server

    Santilli, R M

    1998-01-01

    In this paper we initiate studies of the emerging new forms of energy by using as a representative example the new combustible gas called AquaFuel, discovered and patented by William H. Richardson, jr., whose rights are now owned by Toups Technology Licensing, Inc. (TTL), of Largo, Florida. In essence, AquaFuel is a new energy converter capable of transforming Carbon and water into a new combustible gas via an electric discharge. We show that AquaFuel can be produced easily, safely and rapidly in large amounts, and exhibits greatly reduced emission pollutants as compared to fossil fuels of current use. Despite its simplicity, the chemical and physical characteristics of AquaFuel are largely unknown at this writing. We then review nine basic experimental measurements which are necessary for a scientific appraisal of AquaFuel. We outline the limitations of quantum mechanics and chemistry for the treatment of beyond} said theories. We finally point out the availability of broader theories specifically constructe...

  12. Application of AquaCrop Model for Water Consumption Characteristics of Turfgrass%AquaCrop模型在草坪草耗水特性研究中的应用

    Institute of Scientific and Technical Information of China (English)

    肖波

    2016-01-01

    以草地早熟禾为试验材料,在温室内开展草坪草土壤水分梯度控制试验,将AquaCrop模型应用到非充分灌溉条件下草坪草蒸散耗水特性的研究中,通过参数调试、模型检验和田间验证,最终建立草坪草生物量水分响应模型.结果表明:AquaCrop模型模拟草坪草生长发育的效果与实测结果较为一致,模拟值与测量值非常接近,建立的草坪草AquaCrop模型,具有较强的科学性和实用性.

  13. Coordinated aqua vs methanol substitution kinetics in fac-Re(I) tricarbonyl tropolonato complexes.

    Science.gov (United States)

    Schutte, Marietjie; Roodt, Andreas; Visser, Hendrik G

    2012-11-01

    Water-soluble fac-[Re(CO)(3)(L,L'-Bid)(X)] (L,L'-Bid = tropolonato, X = H(2)O, methanol) complexes have been synthesized, and the aqua and methanol substitution reactions were investigated in water (pH range 6.3-10.0) and methanol, respectively, and compared. Thiocyanate ions were used as monodentate entering ligand. The complexes were characterized by UV-vis, IR, and NMR spectroscopy. The crystal structures of the complexes [NEt(4)] fac-[Re(Trop)(CO)(3)(H(2)O)].NO(3).H(2)O (reactant) and fac-[Re(CO)(3)(Trop)(Py)], a substitution product, are reported. Overall it was found that the aqua substitution of fac-[Re(CO)(3)(Trop)(H(2)O)] is about 10 times faster than the methanol substitution reaction for fac-[Re(CO)(3)(Trop)(MeOH)], with forward and reverse rate and stability constants [k(1) (M(-1) s(-1)), k(-1) (s(-1)), K(1), (M(-1))] for thiocyanate as monodentate entering ligand as follows: fac-[Re(CO)(3)(Trop)(H(2)O)] = 2.54 ± 0.03, 0.0077 ± 0.0005, 330 ± 22/207 ± 14 and fac-[Re(CO)(3)(Trop)(MeOH)] = 0.268 ± 0.002, 0.0044 ± 0.0002, (61 ± 3)/(52 ± 4). The activation parameters [ΔH(‡)(k1) (kJ mol(-1)), ΔS(‡)(k1) (J K(-1) mol(-1))] for the aqua and methanol complex respectively are 56.1 ± 0.7, -49 ± 2 and 64 ± 1, -43 ± 5. PMID:23088314

  14. Aqua-planet simulations of the formation of the South Atlantic convergence zone

    Science.gov (United States)

    Nieto Ferreira, Rosana; Chao, Winston C.

    2013-01-01

    The impact of Amazon Basin convection and cold fronts on the formation and maintenance of the South Atlantic convergence zone (SACZ) is studied using aqua-planet simulations with a general circulation model. In the model, a circular patch of warm sea-surface temperature (SST) is used to mimic the effect of the Amazon Basin on South American monsoon convection. The aqua-planet simulations were designed to study the effect of the strength and latitude of Amazon Basin convection on the formation of the SACZ. The simulations indicate that the strength of the SACZ increases as the Amazon convection intensifies and is moved away from the equator. Of the two controls studied here, the latitude of the Amazon convection exerts the strongest effect on the strength of the SACZ. An analysis of the synoptic-scale variability in the simulations shows the importance of frontal systems in the formation of the aqua-planet SACZ. Composite time series of frontal systems that occurred in the simulations show that a robust SACZ occurs when fronts penetrate into the subtropics and become stationary there as they cross eastward of the longitude of the Amazon Basin. Moisture convergence associated with these frontal systems produces rainfall not along the model SACZ region and along a large portion of the northern model Amazon Basin. Simulations in which the warm SST patch was too weak or too close to the equator did not produce frontal systems that extended into the tropics and became stationary, and did not form a SACZ. In the model, the SACZ forms as Amazon Basin convection strengthens and migrates far enough southward to allow frontal systems to penetrate into the tropics and stall over South America. This result is in agreement with observations that the SACZ tends to form after the onset of the monsoon season in the Amazon Basin.

  15. Evapotranspiration simulated by CRITERIA and AquaCrop models in stony soils

    Directory of Open Access Journals (Sweden)

    Pasquale Campi

    2015-06-01

    Full Text Available The performance of a water balance model is also based on the ability to correctly perform simulations in heterogeneous soils. The objective of this paper is to test CRITERIA and AquaCrop models in order to evaluate their suitability in estimating evapotranspiration at the field scale in two types of soil in the Mediterranean region: non-stony and stony soil. The first step of the work was to calibrate both models under the non-stony conditions. The models were calibrated by using observations on wheat crop (leaf area index or canopy cover, and phenological stages as a function of degree days and pedo-climatic measurements. The second step consisted in the analysing the impact of the soil type on the models performances by comparing simulated and measured values. The outputs retained in the analysis were soil water content (at the daily scale and crop evapotranspiration (at two time scales: daily and crop season. The model performances were evaluated through four statistical tests: normalised difference (D% at the seasonal time scale; and relative root mean square error (RRMSE, efficiency index (EF, coefficient of determination (r2 at the daily scale. At the seasonal scale, values of D% were less than 15% in stony and on-stony soils, indicating a good performance attained by both models. At the daily scale, the RRMSE values (<30% indicate that the evapotranspiration simulated by CRITERIA is acceptable in both soil types. In the stony soil conditions, 3 out 4 statistical tests (RRMSE, EF, r2 indicate the inadequacy of AquaCrop to simulate correctly daily evapotranspiration. The higher performance of CRITERIA model to simulate daily evapotranspiration in stony soils, is due to the soil submodel, which requires the percentage skeleton as an input, while AquaCrop model takes into account the presence of skeleton by reducing the soil volume.

  16. Patterning of platinum (Pt) thin films by chemical wet etching in Aqua Regia

    Science.gov (United States)

    Köllensperger, P. A.; Karl, W. J.; Ahmad, M. M.; Pike, W. T.; Green, M.

    2012-06-01

    The chemical and physical properties of platinum (Pt) make it a useful material for microelectromechanical systems and microfluidic applications such as lab-on-a-chip devices. Platinum thin-films are frequently employed in applications where electrodes with high chemical stability, low electrical resistance or a high melting point are needed. Due to its chemical inertness it is however also one of the most difficult metals to pattern. The gold standard for patterning is chlorine RIE etching, a capital-intensive process not available in all labs. Here we present simple fabrication protocols for wet etching Pt thin-films in hot Aqua Regia based on sputtered Ti/Pt/Cr and Cr/Pt/Cr metal multilayers. Chromium (Cr) or titanium (Ti) is used as an adhesion layer for the Pt. Cr is used as a hard masking layer during the Pt etch as it can be easily and accurately patterned with photoresist and withstands the Aqua Regia. The Cr pattern is transferred into the Pt and the Cr mask later removed. Only standard chemicals and cleanroom equipment/tools are required. Prior to the Aqua Regia etch any surface passivation on the Pt is needs to be removed. This is usually achieved by a quick dip in dilute hydrofluoric acid (HF). HF is usually also used for wet-etching the Ti adhesion layer. We avoid the use of HF for both steps by replacing the HF-dip with an argon (Ar) plasma treatment and etching the Ti layer with a hydrogen peroxide (H2O2) based etchant.

  17. Compensation for Time-Dependent Star Tracker Thermal Deformation on the Aqua Spacecraft

    Science.gov (United States)

    Hashmall, Joseph A.; Natanson, Gregory; Glickman, Jonathan; Sedlak, Joseph

    2004-01-01

    Analysis of attitude sensor data from the Aqua mission showed small but systematic differences between batch least-squares and extended Kalman filter attitudes. These differences were also found to be correlated with star tracker residuals, gyro bias estimates, and star tracker baseplate temperatures. This paper describes the analysis that shows that these correlations are all consistent with a single cause: time-dependent thermal deformation of star tracker alignments. These varying alignments can be separated into relative and common components. The relative misalignments can be determined and compensated for. The common misalignments can only be determined in special cases.

  18. Biomonitoring and risk assessment on earth and during exploratory missions using AquaHab ®

    Science.gov (United States)

    Slenzka, K.; Dünne, M.; Jastorff, B.

    2008-12-01

    Bioregenerative closed ecological life support systems (CELSS) will be necessary in the exploration context revitalizing atmosphere, waste water and producing food for the human CELSS mates. During these long-term space travels and stays far away from Earth in an hostile environment as well as far for example from any hospital and surgery potential, it will be necessary to know much more about chemical and drug contamination in the special sense and by human's themselves in detail. Additionally, there is a strong need on Earth for more relevant standardized test systems including aquatic ones for the prospective risk assessment of chemicals and drugs in general on a laboratory scale. Current standardized test systems are mono species tests, and thus do not represent system aspects and have reduced environmental relevance. The experience gained during the last years in our research group lead to the development of a self-sustaining closed aquatic habitat/facility, called AquaHab ® which can serve regarding space exploration and Earth application. The AquaHab ® module can be the home of several fish species, snails, plants, amphipods and bacteria. The possibility to use different effect endpoints with certain beneficial characteristics is the basis for the application of AquaHab ® in different fields. Influence of drugs and chemicals can be tested on several trophic levels and ecosystem levels; guaranteeing a high relevance for aquatic systems in the real environment. Analyses of effect parameters of different complexity (e.g. general biological and water chemical parameters, activity of biotransforming enzymes) result in broad spectra of sensitivity. Combined with residual analyses (including all metabolites), this leads to an extended prospective risk assessment of a chemical on Earth and in a closed Life Support System. The possibility to measure also sensitive "online" parameters (e.g. behavior, respiration/photosynthetic activity) enables a quick and

  19. Aqua ch´i ©™ - para um envelhecimento ativo

    OpenAIRE

    Mestre, Sabrina

    2012-01-01

    Esta monografia é resultado de um breve estudo sobre o envelhecimento humano e sobre um novo método de terapia aquática pouco conhecido na Europa, o método Spiritwalking: Aqua Ch´i ©™ da Norte Americana Bett Lujan Martinez. Abordaremos, inicialmente, as características do envelhecimento sob os aspetos biopsicosociais, bem como a importância do exercício ao longo do processo de envelhecimento como forma de prevenção, promoção da saúde. A sociedade ocidental, cada vez mais, tem vindo a ad...

  20. Assessment of diverse algorithms applied on MODIS Aqua and Terra data over land surfaces in Europe

    Directory of Open Access Journals (Sweden)

    P. Glantz

    2012-03-01

    Full Text Available The aim of the present study is to validate AOT (aerosol optical thickness and Ångström exponent (α, obtained with the SAER (Satellite AErosol Retrieval algorithm for MODIS (MODerate resolution Imaging Spectroradiometer Aqua and Terra calibrated level 1 data (1 km horizontal resolution at ground and MODIS Collection 5 (c005 standard product retrievals (10 km, against AERONET (AErosol RObotic NETwork observations over land surfaces in Europe. The three time periods investigated in this study have been chosen to enable a validation of the algorithm for a maximal possible variation in sun elevations. For several of the cases analyzed here the Aqua and Terra satellites passed the investigation area twice during a day. Thus, beside a variation in the sun elevation the satellite retrievals have also on a daily basis been performed with a significant variation in the satellite-viewing geometry. An inter-comparison of the two algorithms has also been performed. The validation with AERONET shows that the MODIS c005 retrieved AOT is, for the wavelengths 0.469 and 0.500 nm, on the whole within the expected uncertainty for one standard deviation of the MODIS c005 retrievals over Europe (Δ AOT = ±0.05±0.15 AOT. The SAER estimated AOT for the wavelength 0.443 nm also agree reasonable well with AERONET. Thus, the majority of the SAER AOT values are within the MODIS expected uncertainty range, although somewhat larger root mean square deviation occurs compared to the results obtained with the MODIS c005 algorithm. The discrepancy between SAER and AERONET AOT is, however, substantially larger for the wavelength 488 nm, which means that the values are to a large extent outside of the expected MODIS uncertainty range. Both satellite retrieval algorithms are unable to estimate α accurately, although the MODIS c005 algorithm performs better. Based on the inter-comparison of the SAER and MODIS c005 algorithms it was found that the SAER is able to obtain

  1. Earth System Science Research Using Datra and Products from Terra, Aqua, and ACRIM Satellites

    Science.gov (United States)

    Hutchison, Keith D.

    2007-01-01

    The report describes the research conducted at CSR to extend MODIS data and products to the applications required by users in the State of Texas. This research presented in this report was completed during the timeframe of August 2004 - December 31, 2007. However, since annual reports were filed in December 2005 and 2006, results obtained during calendar year 2007 are emphasized in the report. The stated goals of the project were to complete the fundamental research needed to create two types of new, Level 3 products for the air quality community in Texas from data collected by NASA s EOS Terra and Aqua missions.

  2. Validation of MODIS Terra and Aqua Ice Surface Temperatures at Summit, Greenland

    Science.gov (United States)

    Hall, D. K.; Shuman, C. A.; Xiong, X.; Wenny, B. N.; DiGirolamo, N. E.

    2014-12-01

    Ice-surface temperature (IST) is used in many studies, for example for validation of model output and for detection of leads and thin ice in sea ice. The MODerate-resolution Imaging Spectroradiometer (MODIS) instruments on the Terra and Aqua satellites are useful for mapping IST of sea ice and the Greenland ice sheet (Hall et al., 2012), and validation of the ISTs derived from MODIS has been an ongoing effort (e.g., Koenig & Hall, 2010; Shuman et al., 2014). Recent results call into question the calibration of the MODIS-derived ISTs at very cold temperatures that are characteristic of the Greenland ice sheet high interior during winter (Shuman et al., 2014). In the present work, we investigate the calibration of MODIS IR bands 31 (10.780 - 11.280 µm) and 32 (11.770 - 12.270 µm) under very cold conditions. MODIS IR bands are calibrated using a quadratic algorithm. In Collection 6 (C6), the offset and nonlinear calibration coefficients are computed from data collected during the blackbody cool-down vs the warm-up data used in Collection 5 (C5). To improve the calibration accuracy for low-temperature scenes, the offset terms are set to 0. In general, Aqua MODIS bands 31 and 32 perform better than Terra MODIS bands 31 and 32. One of the reasons is that the Aqua bands have a lower saturation temperature (~340 K) than the Terra (~380 K) bands, and lower saturation or smaller dynamic range means better resolution. As compared to ~2-m NOAA air temperatures (TA) at Summit, Greenland, Shuman et al. (2014) show a small (~0.5°C) offset in Terra MODIS-derived IST vs TA near 0°C, and an increasingly larger offset (up to ~5°C) as TA drops to -60°C. To investigate this further, we compare Terra and Aqua C5 and C6 ISTs with TA data from Summit. This work will document the calibration of bands 31 and 32 at very low temperatures in C5 and C6. Hall, D.K., et al., 2012: Satellite-Derived Climate-Quality Data Record of the Clear-Sky Surface Temperature of the Greenland Ice Sheet

  3. Use of LST images from MODIS/AQUA sensor as an indication of frost occurrence in RS

    Directory of Open Access Journals (Sweden)

    Débora de S. Simões

    2015-10-01

    Full Text Available ABSTRACTAlthough frost occurrence causes severe losses in agriculture, especially in the south of Brazil, the data of minimum air temperature (Tmin currently available for monitoring and predicting frosts show insufficient spatial distribution. This study aimed to evaluate the MDY11A1 (LST – Land Surface Temperature product, from the MODIS sensor on board the AQUA satellite as an estimator of frost occurrence in the southeast of the state of Rio Grande do Sul, Brazil. LST images from the nighttime overpass of the MODIS/AQUA sensor for the months of June, July and August from 2006 to 2012, and data from three conventional weather stations of the National Institute of Meteorology (INMET were used. Consistency was observed between Tmin data measured in weather stations and LST data obtained from the MODIS sensor. According to the results, LSTs below 3 ºC recorded by the MODIS/AQUA sensor are an indication of a favorable scenario to frost occurrence.

  4. Optimized extraction of daily bio-optical time series derived from MODIS/Aqua imagery for Lake Tanganyika, Africa

    DEFF Research Database (Denmark)

    Horion, Stéphanie; Bergamino, N; Stenuite, S;

    2010-01-01

    Lake Tanganyika is one of the world's great freshwater ecosystems. In recent decades its hydrodynamic characteristics have undergone important changes that have had consequences on the lake's primary productivity. The establishment of a long-term Ocean Color dataset for Lake Tanganyika...... the MODIS-Aqua sensor. Standard MODIS Aqua Ocean Color products were found to not provide a suitable calibration for high altitude lakes such as the Lake Tanganyika. An optimization of the extraction process and the validation of the dataset were performed with independent sets of in situ measurements. Our...

  5. Effects of Aqua Aerobics on Body Composition, Body Mass, Lipid Profile, and Blood Count in Middle-Aged Sedentary Women

    OpenAIRE

    Kantyka Joanna; Herman Damian; Roczniok Robert; Kuba Lidia

    2015-01-01

    Purpose. The aim of the present investigations was to determine the effects of aqua aerobics on body weight and composition, lipid profile, and selected blood count parameters in middle-aged sedentary females. Methods. Twenty-one women were randomly assigned to an experimental group (age 56.20 ± 2.57 years, height 162.80 ± 4.76 cm, weight 74.03 ± 3.84 kg) that participated in aqua aerobics classes three times a week for three months and a control group (mean age 56.44 ± 3.28 years, height 165...

  6. AquaResp® — free open-source software for measuring oxygen consumption of resting aquatic animals

    DEFF Research Database (Denmark)

    Svendsen, Morten Bo S.; Skov, Peter Vilhelm; Bushnell, Peter G.;

    AquaResp® is a free open-source software program developed to measure the oxygen consumption of aquatic animals using intermittent flow techniques. This free program is based on Microsoft Excel, and uses the MCC Universal Library and a data acquisition board to acquire analogue readings from up...... manufacturers. AquaResp was developed with the intention of automating data acquisition and control by programming in commonly-available software (Microsoft Excel) and allowing customization by the user without restrictions. The program has been tested in different laboratories for an extended period...

  7. AquaResp® — free open-source software for measuring oxygen consumption of resting aquatic animals

    DEFF Research Database (Denmark)

    Svendsen, Morten Bo S.; Skov, Peter Vilhelm; Bushnell, Peter G.;

    AquaResp® is a free open-source software program developed to measure the oxygen consumption of aquatic animals using intermittent flow techniques. This free program is based on Microsoft Excel, and uses the MCC Universal Library and a data acquisition board to acquire analogue readings from up to...... manufacturers. AquaResp was developed with the intention of automating data acquisition and control by programming in commonly-available software (Microsoft Excel) and allowing customization by the user without restrictions. The program has been tested in different laboratories for an extended period...

  8. Dinuclear ru-aqua complexes for selective epoxidation catalysis based on supramolecular substrate orientation effects

    KAUST Repository

    Di Giovanni, Carlo

    2014-03-03

    Ru-aqua complex {[RuII(trpy)(H2O)] 2(μ-pyr-dc)}+ is a powerful epoxidation catalyst for a wide range of linear and cyclic alkenes. High turnover numbers (TNs), up to 17000, and turnover frequencies (TOF), up to 24120 h-1 (6.7 s -1), have been obtained using PhIO as oxidant. This species presents an outstanding stereospecificity for both cis and trans olefins towards the formation of their corresponding cis and trans epoxides. In addition, it shows different reactivity to cis and trans olefins due to a substrate orientation supramolecular effect transmitted by its ligand scaffold. This effect together with the impressive reaction rates are rationalized using electrochemical techniques and DFT calculations. A new Ru-aqua complex that behaves as a powerful epoxidation catalyst for a wide range of linear and cyclic alkenes is reported. High turnover numbers and frequencies are obtained by using PhIO as oxidant. The complex shows an outstanding stereospecificity for both cis and trans olefins towards the formation of their corresponding cis and trans epoxides (see figure). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Lutetium(iii) aqua ion: On the dynamical structure of the heaviest lanthanoid hydration complex

    Science.gov (United States)

    Sessa, Francesco; Spezia, Riccardo; D'Angelo, Paola

    2016-05-01

    The structure and dynamics of the lutetium(iii) ion in aqueous solution have been investigated by means of a polarizable force field molecular dynamics (MD). An 8-fold square antiprism (SAP) geometry has been found to be the dominant configuration of the lutetium(iii) aqua ion. Nevertheless, a low percentage of 9-fold complexes arranged in a tricapped trigonal prism (TTP) geometry has been also detected. Dynamic properties have been explored by carrying out six independent MD simulations for each of four different temperatures: 277 K, 298 K, 423 K, 632 K. The mean residence time of water molecules in the first hydration shell at room temperature has been found to increase as compared to the central elements of the lanthanoid series in agreement with previous experimental findings. Water exchange kinetic rate constants at each temperature and activation parameters of the process have been determined from the MD simulations. The obtained structural and dynamical results suggest that the water exchange process for the lutetium(iii) aqua ion proceeds with an associative mechanism, in which the SAP hydration complex undergoes temporary structural changes passing through a 9-fold TTP intermediate. Such results are consistent with the water exchange mechanism proposed for heavy lanthanoid atoms.

  10. AquaPathogen X--A template database for tracking field isolates of aquatic pathogens

    Science.gov (United States)

    Emmenegger, Evi; Kurath, Gael

    2012-01-01

    AquaPathogen X is a template database for recording information on individual isolates of aquatic pathogens and is available for download from the U.S. Geological Survey (USGS) Western Fisheries Research Center (WFRC) website (http://wfrc.usgs.gov). This template database can accommodate the nucleotide sequence data generated in molecular epidemiological studies along with the myriad of abiotic and biotic traits associated with isolates of various pathogens (for example, viruses, parasites, or bacteria) from multiple aquatic animal host species (for example, fish, shellfish, or shrimp). The simultaneous cataloging of isolates from different aquatic pathogens is a unique feature to the AquaPathogen X database, which can be used in surveillance of emerging aquatic animal diseases and clarification of main risk factors associated with pathogen incursions into new water systems. As a template database, the data fields are empty upon download and can be modified to user specifications. For example, an application of the template database that stores the epidemiological profiles of fish virus isolates, called Fish ViroTrak (fig. 1), was also developed (Emmenegger and others, 2011).

  11. Aqua Polis

    DEFF Research Database (Denmark)

    Kiib, Hans

    2007-01-01

    A discussion of a range of different strategies related to an sustainable waterfront development, including public space strategies, Housing strategies, Cultural projects, Terrain Vague.......A discussion of a range of different strategies related to an sustainable waterfront development, including public space strategies, Housing strategies, Cultural projects, Terrain Vague....

  12. AquaCrop 模型在农业旱灾损失评估中的应用%Application of AquaCrop model in evaluation of agricultural drought losses

    Institute of Scientific and Technical Information of China (English)

    常文娟; 梁忠民

    2014-01-01

    利用作物生长机理模型---AquaCrop 模型,建立作物生长环境要素(气象、土壤水分等)与产量之间的定量关系,以此构建农业旱灾损失定量评估模型,并对云南省曲靖市沾益县一季中稻的旱灾损失进行了实例计算。结果表明, AquaCrop 模型能够客观地评估农业因旱损失,为旱灾风险分析计算提供灾损数据支撑。%T he AquaCrop model, based on t he mechanism of crop growth process, was introduced to develop the quantitative rela-tionship betw een crop environmental factors( w eather, soil moisture, etc) and crop yields, and t hen to construct a quantitat ive e-valuation model of the agricultural drought losses. The model w as applied to calculate the agricultural drought losses of season rice in Zhanyi County of Qujing City in Yunnan Province. The results showed that the AquaCrop model can assess the agricul-tural drought losses objectively and provide data support for drought risk analysis.

  13. Drought Prediction for Socio-Cultural Stability Project

    Science.gov (United States)

    Peters-Lidard, Christa; Eylander, John B.; Koster, Randall; Narapusetty, Balachandrudu; Kumar, Sujay; Rodell, Matt; Bolten, John; Mocko, David; Walker, Gregory; Arsenault, Kristi; Rheingrover, Scott

    2014-01-01

    The primary objective of this project is to answer the question: "Can existing, linked infrastructures be used to predict the onset of drought months in advance?" Based on our work, the answer to this question is "yes" with the qualifiers that skill depends on both lead-time and location, and especially with the associated teleconnections (e.g., ENSO, Indian Ocean Dipole) active in a given region season. As part of this work, we successfully developed a prototype drought early warning system based on existing/mature NASA Earth science components including the Goddard Earth Observing System Data Assimilation System Version 5 (GEOS-5) forecasting model, the Land Information System (LIS) land data assimilation software framework, the Catchment Land Surface Model (CLSM), remotely sensed terrestrial water storage from the Gravity Recovery and Climate Experiment (GRACE) and remotely sensed soil moisture products from the Aqua/Advanced Microwave Scanning Radiometer - EOS (AMSR-E). We focused on a single drought year - 2011 - during which major agricultural droughts occurred with devastating impacts in the Texas-Mexico region of North America (TEXMEX) and the Horn of Africa (HOA). Our results demonstrate that GEOS-5 precipitation forecasts show skill globally at 1-month lead, and can show up to 3 months skill regionally in the TEXMEX and HOA areas. Our results also demonstrate that the CLSM soil moisture percentiles are a goof indicator of drought, as compared to the North American Drought Monitor of TEXMEX and a combination of Famine Early Warning Systems Network (FEWS NET) data and Moderate Resolution Imaging Spectrometer (MODIS)'s Normalizing Difference Vegetation Index (NDVI) anomalies over HOA. The data assimilation experiments produced mixed results. GRACE terrestrial water storage (TWS) assimilation was found to significantly improve soil moisture and evapotransportation, as well as drought monitoring via soil moisture percentiles, while AMSR-E soil moisture

  14. Optimizing available water capacity using microwave satellite data for improving irrigation management

    Science.gov (United States)

    Gupta, Manika; Bolten, John; Lakshmi, Venkat

    2015-04-01

    This work addresses the improvement of available water capacity by developing a technique for estimating soil hydraulic parameters through the utilization of satellite-retrieved near surface soil moisture. The prototype involves the usage of Monte Carlo analysis to assimilate historical remote sensing soil moisture data available from the Advanced Microwave Scanning Radiometer (AMSR-E) within the hydrological model. The main hypothesis used in this study is that near-surface soil moisture data contain useful information that can describe the effective hydrological conditions of the basin such that when appropriately In the method followed in this study the hydraulic parameters are derived directly from information on the soil moisture state at the AMSR-E footprint scale and the available water capacity is derived for the root zone by coupling of AMSR-E soil moisture with the physically-based hydrological model. The available capacity water, which refers to difference between the field capacity and wilting point of the soil and represent the soil moisture content at 0.33 bar and 15 bar respectively is estimated from the soil hydraulic parameters using the van Genuchten equation. The initial ranges of soil hydraulic parameters are taken in correspondence with the values available from the literature based on Soil Survey Geographic (SSURGO) database within the particular AMSR-E footprint. Using the Monte Carlo simulation, the ranges are narrowed in the region where simulation shows a good match between predicted and near-surface soil moisture from AMSR-E. In this study, the uncertainties in accurately determining the parameters of the nonlinear soil water retention function for large-scale hydrological modeling is the focus of the development of the Bayesian framework. Thus, the model forecasting has been combined with the observational information to optimize the model state and the soil hydraulic parameters simultaneously. The optimization process is divided into

  15. Challenges of linking scientific knowledge to river basin management policy: AquaTerra as a case study

    NARCIS (Netherlands)

    Slob, A.; Rijnveld, M.

    2007-01-01

    The EU Project AquaTerra generates knowledge about the river-soil-sediment-groundwater system and delivers scientific information of value for river basin management. In this article, the use and ignorance of scientific knowledge in decision making is explored by a theoretical review. We elaborate o

  16. Validation of JAXA/MODIS Sea Surface Temperature in Water around Taiwan Using the Terra and Aqua Satellites

    Directory of Open Access Journals (Sweden)

    Ming-An Lee

    2010-01-01

    Full Text Available The research vessel-based Conductivity Temperature Depth profiler (CTD provides underwater measurements of the bulk sea surface temperature (SST at the depths of shallower than 5 m. The CTD observations of the seas around Taiwan provide useful data for comparison with SST of MODIS (Moderate Resolution Imaging Spectroradiometers aboard Aqua and Terra satellites archived by JAXA (Japan Aerospace Exploration Agency. We produce a high-resolution (1 km MODIS SST by using Multi-Channel SST (MCSST algorithm. There were 1516 cloud-free match-up data pairs of MODIS SST and in situ measurements during the period from 2003 - 2005. The difference of the root mean square error (RMSE of satellite observations from each platform during the day and at night was: _ in Aqua daytime, _ in Aqua nighttime, _ in Terra daytime, and _ in Terra nighttime. The total analysis of MODIS-derived SST shows good agreement with a bias of _ and RMSE of _ The analyses indicate that the bias of Aqua daytime was always positive throughout the year and the large RMSE should be attributed to the large positive bias _ under diurnal warming. It was also found that the bias of Terra daytime was usually negative with a mean bias of _ its large RMSE should be treated with care because of low solar radiation in the morning.

  17. Instrumentation of the model in scaled 1:10 to prototype of the AquaBuOY wave energy converter

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Frigaard, Peter

    The objective of this report is to provide guidelines for the instrumentation of a model in scale 1:10 to prototype of the AquaBuOY wave energy converter. The model will be located in Nissum Bredning area: this is an important waterway already used by Aalborg University for real sea tests of wave...

  18. Study on the Retrieval of Snow Depth from FY3B/MWRI in the Atctic

    Science.gov (United States)

    Li, Lele; Chen, Haihua; Guan, Lei

    2016-06-01

    temperatures. Given the high albedo and low thermal conductivity, snow is regarded as one of the key reasons for the amplification of the warming in polar regions. The distributions of sea ice and snow depth are essential to the whole thermal conduction in the Arctic. This study focused on the retrieval of snow depth on sea ice from brightness temperatures of the MicroWave Radiometer Imager (MWRI) onboard the FengYun (FY)-3B satellite during the period from December 1, 2010 to April 30, 2011. After cross calibrated to the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) Level 2A data, the MWRI brightness temperatures were applied to calculate the sea ice concentrations based on the Arctic Radiation and Turbulence Interaction Study Sea Ice (ASI) algorithm. According to the proportional relationship between the snow depth and the surface scattering in 18.7 and 36.5 GHz, the snow depths were derived. In order to eliminate the influence of uncertainties in grain sizes of snow as well as sporadic weather effects, the seven-day averaged snow depths were calculated. Then the results were compared with the snow depths from the AMSR-E Level 3 Sea Ice products. The bias of differences between the MWRI and the AMSR-E Level 3 products are ranged between -1.09 and -0.32 cm while the standard deviations and the correlation coefficients are ranged from 2.47 to 2.88 cm and from 0.78 to 0.90 for different months. As a result, it could be summarized that FY3B/MWRI showed a promising prospect in retrieving snow depth on sea ice.

  19. [Atmospheric Influences Analysis on the Satellite Passive Microwave Remote Sensing].

    Science.gov (United States)

    Qiu, Yu-bao; Shi, Li-juan; Shi, Jian-cheng; Zhao, Shao-jie

    2016-02-01

    Passive microwave remote sensing offers its all-weather work capabilities, but atmospheric influences on satellite microwave brightness temperature were different under different atmospheric conditions and environments. In order to clarify atmospheric influences on Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E), atmospheric radiation were simulated based on AMSR-E configuration under clear sky and cloudy conditions, by using radiative transfer model and atmospheric conditions data. Results showed that atmospheric water vapor was the major factor for atmospheric radiation under clear sky condition. Atmospheric transmittances were almost above 0.98 at AMSR-E's low frequencies (vapor needed to be corrected when using microwave high-frequency channels to inverse land surface parameters in clear sky condition. But under cloud cover or cloudy conditions, cloud liquid water was the key factor to cause atmospheric radiation. When sky was covered by typical stratus cloud, atmospheric transmittances at 10.7, 18.7 and 36.5 GHz were 0.942, 0.828 and 0.605 respectively. Comparing with the clear sky condition, the down-welling atmospheric radiation caused by cloud liquid water increased up to 75.365 K at 36.5 GHz. It showed that the atmospheric correction under different clouds covered condition was the primary work to improve the accuracy of land surface parameters inversion of passive microwave remote sensing. The results also provided the basis for microwave atmospheric correction algorithm development. Finally, the atmospheric sounding data was utilized to calculate the atmospheric transmittance of Hailaer Region, Inner Mongolia province, in July 2013. The results indicated that atmospheric transmittances were close to 1 at C-band and X-band. 89 GHz was greatly influenced by water vapor and its atmospheric transmittance was not more than 0.7. Atmospheric transmittances in Hailaer Region had a relatively stable value in summer, but had about 0

  20. Space-based passive microwave soil moisture retrievals and the correction for a dynamic open water fraction

    Directory of Open Access Journals (Sweden)

    B. T. Gouweleeuw

    2012-06-01

    Full Text Available The large observation footprint of low-frequency satellite microwave emissions complicates the interpretation of near-surface soil moisture retrievals. While the effect of sub-footprint lateral heterogeneity is relatively limited under unsaturated conditions, open water bodies (if not accounted for cause a strong positive bias in the satellite-derived soil moisture retrieval. This bias is generally assumed static and associated with large, continental lakes and coastal areas. Temporal changes in the extent of smaller water bodies as small as a few percent of the sensor footprint size, however, can cause significant and dynamic biases. We analysed the influence of such small open water bodies on near-surface soil moisture products derived from actual (non-synthetic data from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E for three areas in Oklahoma, USA. Differences between on-ground observations, model estimates and AMSR-E retrievals were related to dynamic estimates of open water fraction, one retrieved from a global daily record based on higher frequency AMSR-E data, a second derived from the Moderate Resolution Imaging Spectroradiometer (MODIS and a third through inversion of the radiative transfer model, used to retrieve soil moisture. The comparison demonstrates the presence of relatively small areas (<0.05 of open water in or near the sensor footprint, possibly in combination with increased, below-critical vegetation density conditions (optical density <0.8, which contribute to seasonally varying biases in excess of 0.2 (m3 m−3 soil water content. These errors need to be addressed, either through elimination or accurate characterisation, if the soil moisture retrievals are to be used effectively in a data assimilation scheme.

  1. Estimating error cross-correlations in soil moisture data sets using extended collocation analysis

    Science.gov (United States)

    Gruber, A.; Su, C.-H.; Crow, W. T.; Zwieback, S.; Dorigo, W. A.; Wagner, W.

    2016-02-01

    Global soil moisture records are essential for studying the role of hydrologic processes within the larger earth system. Various studies have shown the benefit of assimilating satellite-based soil moisture data into water balance models or merging multisource soil moisture retrievals into a unified data set. However, this requires an appropriate parameterization of the error structures of the underlying data sets. While triple collocation (TC) analysis has been widely recognized as a powerful tool for estimating random error variances of coarse-resolution soil moisture data sets, the estimation of error cross covariances remains an unresolved challenge. Here we propose a method—referred to as extended collocation (EC) analysis—for estimating error cross-correlations by generalizing the TC method to an arbitrary number of data sets and relaxing the therein made assumption of zero error cross-correlation for certain data set combinations. A synthetic experiment shows that EC analysis is able to reliably recover true error cross-correlation levels. Applied to real soil moisture retrievals from Advanced Microwave Scanning Radiometer-EOS (AMSR-E) C-band and X-band observations together with advanced scatterometer (ASCAT) retrievals, modeled data from Global Land Data Assimilation System (GLDAS)-Noah and in situ measurements drawn from the International Soil Moisture Network, EC yields reasonable and strong nonzero error cross-correlations between the two AMSR-E products. Against expectation, nonzero error cross-correlations are also found between ASCAT and AMSR-E. We conclude that the proposed EC method represents an important step toward a fully parameterized error covariance matrix for coarse-resolution soil moisture data sets, which is vital for any rigorous data assimilation framework or data merging scheme.

  2. Poly[aqua(μ3-pyridazine-4-carboxylato-κ2O:O:O′lithium

    Directory of Open Access Journals (Sweden)

    Wojciech Starosta

    2011-04-01

    Full Text Available The structure of the title compound, [Li(C5H3N2O2(H2O]n, is composed of centrosymmetric dimers in which two LiI ions are bridged by a carboxylate O atom, each donated by a ligand, acting in a bidentate mode. The second carboxylato O atoms bridge the dimers to LiI ions in adjacent dimers, forming molecular layers parallel to (001. Each LiI ion is coordinated by two bridging carboxylate O atoms, a bridging carboxylate O atom donated by the adjacent dimer and an aqua O atom, resulting in a distorted tetrahedral coordination geometry. The layers are held together by O—H...N hydrogen bonds in which coordinated water O atoms act as donors and ligand hetero-ring N atoms as acceptors.

  3. Visible-Light-Induced Morphological Changes of Giant Vesicles by Photoisomerization of a Ruthenium Aqua Complex.

    Science.gov (United States)

    Hirahara, Masanari; Tsukamoto, Akira; Goto, Hiroki; Tada, Shigeru; Yagi, Masayuki; Umemura, Yasushi

    2016-02-18

    Visible- and red-light responsive vesicles were prepared by incorporating a ruthenium aqua complex having two alkyl chains on tridentate and asymmetrical bidentate ligands (proximal-2: [Ru(C10 tpy)(C10 pyqu)OH2 ](2+) , C10 tpy=4'-decyloxy-2,2';6',2"-terpyridine, C10 pyqu=2-[2'-(6'-decyloxy)-pyridyl]quinoline). The ruthenium complex of proximal-2 with closed alkyl chain geometry and a cylinder-like molecular shape exhibited photoisomerization to distal-2 with an open alkyl chain geometry and a cone-like shape, both in an aqueous solution and in vesicle dispersions. We observed that light irradiation of giant vesicles containing proximal-2 induced diverse morphological changes. PMID:26711139

  4. Aerosol retrieval over land by exploiting the synergy of TERRA and AQUA MODIS DATA

    Institute of Scientific and Technical Information of China (English)

    TANG; Jiakui; XUE; Yong; YU; Tong; GUAN; Yanning; CAI; Guoyin

    2006-01-01

    Aerosol retrieval over land from satellite remotely sensed data remains internationally a difficult task. By using MODIS data, the Dark Dense Vegetation (DDV) algorithm aerosol distribution and properties retrieval over land has shown excellent competence. However, this algorithm is restricted to lower surface reflectance such as water bodies and dense vegetation, which limits its actual application, and is unable to be used for high reflective surface such as over urban areas. In this paper, we introduce a new aerosol retrieval model by exploiting the Synergy of TERRA and AQUA MODIS data (SYNTAM), which can be used for various ground surfaces, including for high reflective surface. Preliminary validations have been carried out by comparing with AERONET measured data, which shows good accuracy and promising potential. Further research work is undergoing.

  5. Terra, Aqua, and Aura Direct Broadcast - Providing Earth Science Data for Realtime Applications

    Science.gov (United States)

    Kelly, Angelita C.; Coronado, Patrick L.; Case, Warren F.; Franklin, Ameilia

    2010-01-01

    The need for realtime data to aid in disaster management and monitoring has been clearly demonstrated for the past several years, e.g., during the tsunami in Indonesia in 2004, the hurricane Katrina in 2005, fires, etc. Users want (and often require) the means to get earth observation data for operational regional use as soon as they are generated by satellites. This is especially true for events that can cause loss of human life and/or property. To meet this need, NASA's Earth Observing System (EOS) satellites, Terra and Aqua, provide realtime data useful to disaster management teams. This paper describes the satellites, their Direct Broadcast (DB) capabilities, the data uses, what it takes to deploy a DB ground station, and the future of the DB.

  6. Irrigation management strategies for winter wheat using AquaCrop model

    Directory of Open Access Journals (Sweden)

    M. H. Ali

    2013-09-01

    Full Text Available Many regions of the world face the challenge to ensure high yield with limited water supply. This calls for utilization of available water in an efficient and sustainable manner. Quantitative models can assist in management decision and planning purposes. The FAO’s newly developed crop-water model, AquaCrop, which simulates yield in response to water, has been calibrated for winter wheat and subsequently used to simulate yield under different sowing dates, irrigation frequencies, and irrigation sequences using 10 years daily weather data. The simulation results suggest that “2 irrigation frequency” is the most water-efficient schedule for wheat under the prevailing climatic and soil conditions. The results also indicate decreasing yield trend under late sowing. The normal/recommended sequence of irrigation performed better than the seven-days shifting from the normal. The results will help to formulate irrigation management plan based on the resource availability (water, and land availability from previous crop.

  7. Launching the AquaMAV: bioinspired design for aerial-aquatic robotic platforms.

    Science.gov (United States)

    Siddall, R; Kovač, M

    2014-09-01

    Current Micro Aerial Vehicles (MAVs) are greatly limited by being able to operate in air only. Designing multimodal MAVs that can fly effectively, dive into the water and retake flight would enable applications of distributed water quality monitoring, search and rescue operations and underwater exploration. While some can land on water, no technologies are available that allow them to both dive and fly, due to dramatic design trade-offs that have to be solved for movement in both air and water and due to the absence of high-power propulsion systems that would allow a transition from underwater to air. In nature, several animals have evolved design solutions that enable them to successfully transition between water and air, and move in both media. Examples include flying fish, flying squid, diving birds and diving insects. In this paper, we review the biological literature on these multimodal animals and abstract their underlying design principles in the perspective of building a robotic equivalent, the Aquatic Micro Air Vehicle (AquaMAV). Building on the inspire-abstract-implement bioinspired design paradigm, we identify key adaptations from nature and designs from robotics. Based on this evaluation we propose key design principles for the design of successful aerial-aquatic robots, i.e. using a plunge diving strategy for water entry, folding wings for diving efficiency, water jet propulsion for water takeoff and hydrophobic surfaces for water shedding and dry flight. Further, we demonstrate the feasibility of the water jet propulsion by building a proof-of-concept water jet propulsion mechanism with a mass of 2.6 g that can propel itself up to 4.8 m high, corresponding to 72 times its size. This propulsion mechanism can be used for AquaMAV but also for other robotic applications where high-power density is of use, such as for jumping and swimming robots. PMID:24615533

  8. An Algorithm For Climate-Quality Atmospheric Profiling Continuity From EOS Aqua To Suomi-NPP

    Science.gov (United States)

    Moncet, J. L.

    2015-12-01

    We will present results from an algorithm that is being developed to produce climate-quality atmospheric profiling earth system data records (ESDRs) for application to hyperspectral sounding instrument data from Suomi-NPP, EOS Aqua, and other spacecraft. The current focus is on data from the S-NPP Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) instruments as well as the Atmospheric InfraRed Sounder (AIRS) on EOS Aqua. The algorithm development at Atmospheric and Environmental Research (AER) has common heritage with the optimal estimation (OE) algorithm operationally processing S-NPP data in the Interface Data Processing Segment (IDPS), but the ESDR algorithm has a flexible, modular software structure to support experimentation and collaboration and has several features adapted to the climate orientation of ESDRs. Data record continuity benefits from the fact that the same algorithm can be applied to different sensors, simply by providing suitable configuration and data files. The radiative transfer component uses an enhanced version of optimal spectral sampling (OSS) with updated spectroscopy, treatment of emission that is not in local thermodynamic equilibrium (non-LTE), efficiency gains with "global" optimal sampling over all channels, and support for channel selection. The algorithm is designed for adaptive treatment of clouds, with capability to apply "cloud clearing" or simultaneous cloud parameter retrieval, depending on conditions. We will present retrieval results demonstrating the impact of a new capability to perform the retrievals on sigma or hybrid vertical grid (as opposed to a fixed pressure grid), which particularly affects profile accuracy over land with variable terrain height and with sharp vertical structure near the surface. In addition, we will show impacts of alternative treatments of regularization of the inversion. While OE algorithms typically implement regularization by using background estimates from

  9. Evaluation of Aqua-Ammonia Chiller Technologies and Field Site Installation

    Energy Technology Data Exchange (ETDEWEB)

    Zaltash, Abdolreza [ORNL

    2007-09-01

    The Naval Facilities Engineering Service Center (NFESC) has sponsored Oak Ridge National Laboratory (ORNL) to review, select, and evaluate advanced, gas-fired, 5-ton, aqua-ammonia, chiller technologies. The selection criteria was that units have COP values of 0.67 or better at Air-conditioning and Refrigeration Institute (ARI) 95 F outdoor rating conditions, an active refrigerant flow control, and a variable-speed condenser fan. These features are expected to allow these units to operate at higher ambient temperatures (up to the maximum operating temperature of 110 F) with minimal degradation in performance. ORNL evaluated three potential manufacturers of advanced, gas-fired, 5-ton, aqua-ammonia chillers-Robur, Ambian, and Cooling Technologies. Unfortunately, Robur did not meet the COP requirements and Cooling Technologies could not deliver a unit to be tested at the U.S. Department of Energy (DOE)-ORNL environmental chamber testing facility for thermally activated heat pumps. This eliminated these two technologies from further consideration, leaving only the Ambian chillers for evaluation. Two Ambian chillers were evaluated at the DOE-ORNL test facility. Overall these chillers operated well over a wide range of ambient conditions with minimal degradation in performance due to several control strategies used such as a variable speed condenser fan, a modulating burner, and active refrigerant flow control. These Ambian pre-commercial units were selected for installation and field testing at three federal facilities. NFESC worked with ORNL to assist with the site selection for installation and evaluation of these chillers. Two sites (ORNL and Naval Surface Warfare Center [NSWC] Corona) had a single chiller unit installed; and at one site (Naval Amphibious Base [NAB] Little Creek), two 5-ton chillers linked together were installed to provide 10 tons of cooling. A chiller link controller developed under this project was evaluated in the field test at Little Creek.

  10. Expression and localization of aqua-glyceroporins AQP3 and AQP9 in rat oral epithelia.

    Science.gov (United States)

    Poveda, Marlene; Hashimoto, Sadamitsu; Enokiya, Yasunobu; Matsuki-Fukushima, Miwako; Sasaki, Hodaka; Sakurai, Kaoru; Shimono, Masaki

    2014-01-01

    Aquaporins (AQPs) are a family of small integral membrane proteins made up of 6 hydrophobic, a-helical, membrane-spanning domains surrounding a highly selective aqueous pore. AQP3, AQP7, and AQP9, termed aqua-glyceroporins, are known to be involved in the transport of water, glycerol, and other small molecules. In this study, we investigated the expression and localization of aqua-glyceroporins in rat oral stratified squamous epithelia of the palate, the buccal mucosa, the inferior aspect of the tongue, and the oral floor by using RT-PCR, immunofluorescence, and immunogold electron microscopy. AQP3 and AQP9 mRNAs were expressed in whole oral epithelium. Immunostaining for AQP3 was recognized in each type of epithelium. The results suggest that AQP3 synthesis begins predominantly in the cytoplasm of the basal cells. During the process of epithelial cell differentiation, AQP3 protein appears to accumulate and be transported to the plasma membrane, from where it is incorporated into the cornified or surface layers. The intracellular localization of AQP3 appears to correlate with the differentiation of keratinocytes, suggesting that it acts as an enhancer of the physiological permeability barrier together with membrane coating granules. The distribution pattern of AQP9 was limited to the marginal areas of the basal and suprabasal layers, which was different from that of AQP3. This difference in distribution between AQP3 and AQP9 suggests that AQP9 in rat oral epithelia acts as a channel by facilitating glycerol uptake from the blood through the endothelial cells of the capillary vessels to the oral stratified squamous epithelium. AQP3 and AQP9 facilitate both transcellular osmotic water flow and glycerol transport as pore-like passive transporters in the keratinocytes of oral epithelia, and may play a key role in not only hydration and the permeability barrier, but also cell proliferation, differentiation, migration, development, and wound healing by generating ATP.

  11. Launching the AquaMAV: bioinspired design for aerial–aquatic robotic platforms

    International Nuclear Information System (INIS)

    Current Micro Aerial Vehicles (MAVs) are greatly limited by being able to operate in air only. Designing multimodal MAVs that can fly effectively, dive into the water and retake flight would enable applications of distributed water quality monitoring, search and rescue operations and underwater exploration. While some can land on water, no technologies are available that allow them to both dive and fly, due to dramatic design trade-offs that have to be solved for movement in both air and water and due to the absence of high-power propulsion systems that would allow a transition from underwater to air. In nature, several animals have evolved design solutions that enable them to successfully transition between water and air, and move in both media. Examples include flying fish, flying squid, diving birds and diving insects. In this paper, we review the biological literature on these multimodal animals and abstract their underlying design principles in the perspective of building a robotic equivalent, the Aquatic Micro Air Vehicle (AquaMAV). Building on the inspire–abstract–implement bioinspired design paradigm, we identify key adaptations from nature and designs from robotics. Based on this evaluation we propose key design principles for the design of successful aerial–aquatic robots, i.e. using a plunge diving strategy for water entry, folding wings for diving efficiency, water jet propulsion for water takeoff and hydrophobic surfaces for water shedding and dry flight. Further, we demonstrate the feasibility of the water jet propulsion by building a proof-of-concept water jet propulsion mechanism with a mass of 2.6 g that can propel itself up to 4.8 m high, corresponding to 72 times its size. This propulsion mechanism can be used for AquaMAV but also for other robotic applications where high-power density is of use, such as for jumping and swimming robots. (topical review)

  12. Parameterization and application of the AquaCrop model for simulating bioenergy crops in Oklahoma

    Science.gov (United States)

    Bilga, Navneet Kaur

    The objective of this study was to parameterize the AquaCrop model for two bioenergy crops, switchgrass and forage sorghum, using field measurements from Stillwater, Oklahoma in 2011. The parameterized model was then validated for additional sites at Chickasha and Woodward, Oklahoma. After parameterization at Stillwater, the simulated canopy cover closely matched the measured canopy cover dynamics with a RMSE of 6% in switchgrass and 5% in forage sorghum. The water stress thresholds for canopy expansion and stomatal conductance were similar for switchgrass and forage sorghum, but senescence was induced at 35% available water depletion for forage sorghum compared to 85% for switchgrass. The maximum rooting depth of switchgrass was estimated at 190 cm and that of forage sorghum at 120 cm. The normalized water productivity of switchgrass was found to be 14 g m-2, approximately half that of forage sorghum which was 27 g m-2. The parameterized model reasonably simulated soil water depletion at Stillwater (RMSE AquaCrop five water levels: rainfed with initial soil moisture conditions of 60% available water capacity, 80% available water capacity, 100% available water capacity, and irrigation treatments at 70% allowable depletion, and at 50% allowable depletion. The simulation study was done over a period of ten years 2002-2011 to assess the long term performance. County average yields were consistent with simulated grain yields for corn under irrigated and rainfed conditions. Forage sorghum produced 30 % higher theoretical ethanol yields than corn under irrigated environments but not under rainfed environments. Switchgrass did not produce significantly higher theoretical ethanol yields than corn at any water level. Based on this modeling study, forage sorghum may have potential as an alternative to corn in the Oklahoma Panhandle given the advent of cellulosic ethanol production but forage sorghum is unlikely to help meet the challenge of groundwater depletion.

  13. A decadal microwave record of tropical air temperature from AMSU-A/aqua observations

    Science.gov (United States)

    Shi, Yuan; Li, King-Fai; Yung, Yuk L.; Aumann, Hartmut H.; Shi, Zuoqiang; Hou, Thomas Y.

    2013-09-01

    Atmospheric temperature is one of the most important climate variables. This observational study presents detailed descriptions of the temperature variability imprinted in the 9-year brightness temperature data acquired by the Advanced Microwave Sounding Unit-Instrument A (AMSU-A) aboard Aqua since September 2002 over tropical oceans. A non-linear, adaptive method called the Ensemble Joint Multiple Extraction has been employed to extract the principal modes of variability in the AMSU-A/Aqua data. The semi-annual, annual, quasi-biennial oscillation (QBO) modes and QBO-annual beat in the troposphere and the stratosphere have been successfully recovered. The modulation by the El Niño/Southern oscillation (ENSO) in the troposphere was found and correlates well with the Multivariate ENSO Index. The long-term variations during 2002-2011 reveal a cooling trend (-0.5 K/decade at 10 hPa) in the tropical stratosphere; the trend below the tropical tropopause is not statistically significant due to the length of our data. A new tropospheric near-annual mode (period ~1.6 years) was also revealed in the troposphere, whose existence was confirmed using National Centers for Environmental Prediction Reanalysis air temperature data. The near-annual mode in the troposphere is found to prevail in the eastern Pacific region and is coherent with a near-annual mode in the observed sea surface temperature over the Warm Pool region that has previously been reported. It remains a challenge for climate models to simulate the trends and principal modes of natural variability reported in this work.

  14. Launching the AquaMAV: bioinspired design for aerial-aquatic robotic platforms.

    Science.gov (United States)

    Siddall, R; Kovač, M

    2014-09-01

    Current Micro Aerial Vehicles (MAVs) are greatly limited by being able to operate in air only. Designing multimodal MAVs that can fly effectively, dive into the water and retake flight would enable applications of distributed water quality monitoring, search and rescue operations and underwater exploration. While some can land on water, no technologies are available that allow them to both dive and fly, due to dramatic design trade-offs that have to be solved for movement in both air and water and due to the absence of high-power propulsion systems that would allow a transition from underwater to air. In nature, several animals have evolved design solutions that enable them to successfully transition between water and air, and move in both media. Examples include flying fish, flying squid, diving birds and diving insects. In this paper, we review the biological literature on these multimodal animals and abstract their underlying design principles in the perspective of building a robotic equivalent, the Aquatic Micro Air Vehicle (AquaMAV). Building on the inspire-abstract-implement bioinspired design paradigm, we identify key adaptations from nature and designs from robotics. Based on this evaluation we propose key design principles for the design of successful aerial-aquatic robots, i.e. using a plunge diving strategy for water entry, folding wings for diving efficiency, water jet propulsion for water takeoff and hydrophobic surfaces for water shedding and dry flight. Further, we demonstrate the feasibility of the water jet propulsion by building a proof-of-concept water jet propulsion mechanism with a mass of 2.6 g that can propel itself up to 4.8 m high, corresponding to 72 times its size. This propulsion mechanism can be used for AquaMAV but also for other robotic applications where high-power density is of use, such as for jumping and swimming robots.

  15. 基于寒地春小麦AquaCrop与WOFOST模型适应性验证分析%The Adaptability Test Analysis of AquaCrop and WOFOST Model Based on the Cold Spring Wheat

    Institute of Scientific and Technical Information of China (English)

    张铁楠; 付驰; 李晶; 顾万荣; 许为政; 芦玉双; 魏湜

    2013-01-01

    使用AquaCrop模型与WOFOST模型对哈尔滨地区春小麦生长进行模拟,以春小麦的地上生物量和产量及生育期土壤体积含水量为指标,对比分析两个模型的模拟精度.结果表明:使用经过校正的两个模型均能够较为准确地模拟哈尔滨地区春小麦的生长发育情况及产量形成,观测值与模拟值一致性较好,误差均在合理范围内.在非正常年际AquaCrop模型模拟结果与实测结果偏差较大,说明该模型适合于正常年景的作物生长模拟,WOFOST模型适应性更强.在对201 1年土壤水分含量的模拟中,两个模型观测值与模拟值总体趋势相同,误差均在合理范围内.总体来说,经过修正和校准后的AquaCrop模型与WOFOST模型均适合寒地春小麦的模拟研究.%The main object of the study was analyzing the accuracy of the two models AquaCrop and WOFOST which were used for simulating the growth of spring wheat in Harbin based on biomass,yield and soil volume moisture content.The results indicated that the spring wheat growth and yield formation could be simulated accurately with the two optimized models.What's more,the values of observation and simulation value were closer and the error was creditable.The simulation results of AquaCrop model exhibit more difference with the measured results in abnormal year which revealed that the model was suitable for the crop growth in normal year while the WOFOST model showed more adaptability.The observation values of soil moisture content in 2011 were consistent with the total trend in the two models used in the research,also the error was creditable.In general,the optimized models AquaCrop and WOFOST were suitable for the cold spring wheat simulation research.

  16. 基于星载激光雷达的气溶胶光学厚度与海面风速关系研究%Relationship between aerosol optical depth and sea surface wind speed based on CALIPSO lidar measurements

    Institute of Scientific and Technical Information of China (English)

    汤佳沅; 吴东

    2013-01-01

    海面上空气溶胶的产生和传输在一定程度上和风有关,研究气溶胶和风速间的关系,对增加大气模式的预测精度有重要意义.使用CALIPSO卫星CALIOP激光雷达L2(V3.01)气溶胶层与云层数据,与准同步AQUA卫星的AMSR-E海面风速数据,采用2007年和2008年1月、4月、7月、10月共8个月的观测数据,研究波长为532 nm的气溶胶光学厚度(AOD)与海面风速间的关系及其随季节、年份的变化.结果显示,无云条件下,全球海洋上空AOD与风速存在关系:当风速在0~12 m/s时,AOD随风速增大而增加,当风速在4~12 m/s时,AOD与风速近似线性关系,当风速大于14 m/s时,AOD趋于平稳.%Aerosol production and transmission over oceans are related to wind in some extent. Research on the relationship between wind speed and aerosol might increase the accuracy of forecast, which has important meaning to atmospheric model. The relationship between aerosol optical depth (AOD) and sea surface wind speed was explored using remotely sensed data from cloud-aerosol lidar with orthogonal polarization (CALIOP) on board CALIPSO satellite and collocated advanced microwave scanning radiometer (AMSR-E) on board AQUA satellite. Measurements in eight months (January, April, July and October, 2007 and 2008) were used to study the relationship between sea surface wind speed and AOD at the wavelength of 532 nm, and its changes with seasons and years. The results show that, in cloud free condition, aerosol optical depth over global ocean is related to sea surface wind speed. For wind speed less than 12 m/s, AOD increases with wind speed. For wind speed between 4 m/s and 12 m/s, AOD increases quasi-linearly with the increase in surface wind. For higher wind speed values, I.e. Wind speed is more than 14 m/s, and the relationship shows a tendency toward leveling off.

  17. Model of recreational and training sessions based on the use of funds aqua professionally applied in the preparation of students of economics

    Directory of Open Access Journals (Sweden)

    Petrenko N. V.

    2014-07-01

    Full Text Available Purpose : study, develop and test a model of health-training exercises with the use of aqua. Material: in the experiment involved 69 students aged 17-18 years. Results : It was found that the developed model has a positive effect on physical performance of students promotes adaptive processes to the future professional activity and improve the learning process. Should consider the following: 1 the means and methods should be adequate aqua morphofunctional features and enhance the activity of the cardiovascular system, general endurance, power capabilities, flexibility, neurobehavioral performance, and 2 as a means of aqua aerobic exercise is advisable to use orientation and moderate intensity, and 3 use tools and techniques aqua should foster interest in a systematic and independent physical activities. Conclusions : the model promotes the development and improvement of the skills and abilities necessary to the future experts in economics.

  18. GHRSST Level 2P Global Skin Sea Surface Temperature from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the NASA Aqua satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Moderate-resolution Imaging Spectroradiometer (MODIS) is a scientific instrument (radiometer) launched by NASA in 2002 on board the Aqua satellite platform (a...

  19. AquaScan: A miniaturized UV/VIS/IR hyperspectral imager for autonomous airborne and underwater imaging spectroscopy of coastal & oceanic environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The AquaScan, a miniaturized UV/VIS/NIR hyperspectral imager will be built for deployment on a UAV or small manned aircraft for ocean coastal remote sensing...

  20. MODIS/Aqua MYD11A2 Land Surface Temperature & Emissivity 8-Day L3 Global 1km Gird SIN Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The MODIS/Aqua Land Surface Temperature and Emissivity (LST/E) products provide per-pixel temperature and emissivity values in a sequence of swath-based global...

  1. MODIS/Aqua MYD11_L2 Land Surface Temperature and Emissivity 5-Minute L2 Swath 1 km Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The MODIS/Aqua Land Surface Temperature and Emissivity (LST/E) products provide per-pixel temperature and emissivity values in a sequence of swath-based global...

  2. MODIS/Aqua MYD11C3 Land Surface Temperature/Emissivity Monthly L3 Global 0.05Deg CMG Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The MODIS/Aqua Land Surface Temperature and Emissivity (LST/E) products provide per-pixel temperature and emissivity values in a sequence of swath-based global...

  3. MODIS/Aqua MYD11A1 Land Surface Temperature and Emissivity Daily L3 Global 1 km Grid SIN Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The MODIS/Aqua Land Surface Temperature and Emissivity (LST/E) products provide per-pixel temperature and emissivity values in a sequence of swath-based global...

  4. MODIS/Aqua MYD11C2 Land Surface Temperature/Emissivity 8-Day L3 Global 0.05Deg CMG Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The MODIS/Aqua Land Surface Temperature and Emissivity (LST/E) products provide per-pixel temperature and emissivity values in a sequence of swath-based global...

  5. MODIS/Aqua MYD11B1 Land Surface Temperature and Emissivity Daily L3 Global 5 km Grid SIN Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The MODIS/Aqua Land Surface Temperature and Emissivity (LST/E) products provide per-pixel temperature and emissivity values in a sequence of swath-based global...

  6. MODIS/Aqua MYD11C1 Land Surface Temperature and Emissivity Daily L3 Global 0.05Deg CMG Version 6

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The MODIS/Aqua Land Surface Temperature and Emissivity (LST/E) products provide per-pixel temperature and emissivity values in a sequence of swath-based global...

  7. Monitoring the Snowpack in Remote, Ungauged Mountains

    Science.gov (United States)

    Dozier, J.; Davis, R. E.; Bair, N.; Rittger, K. E.

    2013-12-01

    Our objective is to estimate seasonal snow volumes, relative to historical trends and extremes, in snow-dominated mountains that have austere infrastructure, sparse gauging, challenges of accessibility, and emerging or enduring insecurity related to water resources. The world's mountains accumulate substantial snow and, in some areas, produce the bulk of the runoff. In ranges like Afghanistan's Hindu Kush, availability of water resources affects US policy, military and humanitarian operations, and national security. The rugged terrain makes surface measurements difficult and also affects the analysis of remotely sensed data. To judge feasibility, we consider two regions, a validation case and a case representing inaccessible mountains. For the validation case, we use the Sierra Nevada of California, a mountain range of extensive historical study, emerging scientific innovation, and conflicting priorities in managing water for agriculture, urban areas, hydropower, recreation, habitat, and flood control. For the austere regional focus, we use the Hindu Kush, where some of the most persistent drought in the world causes food insecurity and combines with political instability, and occasional flooding. Our approach uses a mix of satellite data and spare modeling to present information essential for planning and decision making, ranging from optimization of proposed infrastructure projects to assessment of water resources stored as snow for seasonal forecasts. We combine optical imagery (MODIS on Terra/Aqua), passive microwave data (SSM/I and AMSR-E), retrospective reconstruction with energy balance calculations, and a snowmelt model to establish the retrospective context. With the passive microwave data we bracket the historical range in snow cover volume. The rank orders of total retrieved volume correlates with reconstructions. From a library of historical reconstruction, we find similar cases that provide insights about snow cover distribution at a finer scale than

  8. A Case Study on Maximizing Aqua Feed Pellet Properties Using Response Surface Methodology and Genetic Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    JayaShankar Tumuluru

    2013-04-01

    Aims: The present case study is on maximizing the aqua feed properties using response surface methodology and genetic algorithm. Study Design: Effect of extrusion process variables like screw speed, L/D ratio, barrel temperature, and feed moisture content were analyzed to maximize the aqua feed properties like water stability, true density, and expansion ratio. Place and Duration of Study: This study was carried out in the Department of Agricultural and Food Engineering, Indian Institute of Technology, Kharagpur, India. Methodology: A variable length single screw extruder was used in the study. The process variables selected were screw speed (rpm), length-to-diameter (L/D) ratio, barrel temperature (degrees C), and feed moisture content (%). The pelletized aqua feed was analyzed for physical properties like water stability (WS), true density (TD), and expansion ratio (ER). Extrusion experimental data was collected by based on central composite design. The experimental data was further analyzed using response surface methodology (RSM) and genetic algorithm (GA) for maximizing feed properties. Results: Regression equations developed for the experimental data has adequately described the effect of process variables on the physical properties with coefficient of determination values (R2) of > 0.95. RSM analysis indicated WS, ER, and TD were maximized at L/D ratio of 12-13, screw speed of 60-80 rpm, feed moisture content of 30-40%, and barrel temperature of = 80 degrees C for ER and TD and > 90 degrees C for WS. Based on GA analysis, a maxium WS of 98.10% was predicted at a screw speed of 96.71 rpm, L/D radio of 13.67, barrel temperature of 96.26 degrees C, and feed moisture content of 33.55%. Maximum ER and TD of 0.99 and 1346.9 kg/m3 was also predicted at screw speed of 60.37 and 90.24 rpm, L/D ratio of 12.18 and 13.52, barrel temperature of 68.50 and 64.88 degrees C, and medium feed moisture content of 33.61 and 38.36%. Conclusion: The present data analysis indicated

  9. Inter-Comparison of S-NPP VIIRS and Aqua MODIS Thermal Emissive Bands Using Hyperspectral Infrared Sounder Measurements as a Transfer Reference

    OpenAIRE

    Yonghong Li; Aisheng Wu; Xiaoxiong Xiong

    2016-01-01

    This paper compares the calibration consistency of the spectrally-matched thermal emissive bands (TEB) between the Suomi National Polar-orbiting Partnership (S-NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) and the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS), using observations from their simultaneous nadir overpasses (SNO). Nearly-simultaneous hyperspectral measurements from the Aqua Atmospheric Infrared Sounder(AIRS) and the S-NPP Cross-track Infrared Sounder (CrIS) a...

  10. 中国干旱区积雪面积产品去云处理方法验证与评估%Validation and Assessment of Cloud Obscuration Reduction of Snow Cover Products in Arid Areas in China

    Institute of Scientific and Technical Information of China (English)

    王增艳; 车涛

    2012-01-01

    Cloud coverage in daily snow cover products is a main obstacle in using Moderate Resolution Imaging Spectroradiometer(MODIS).In this study,the multi-temporal and multi-sensor combination approaches are applied to reduce cloud obscuration with Aqua Advanced Microwave Scanning Radiometer for NASA'S Earth Observing System(AMSR-E) snow depth products introduced as the auxiliary data to develop 6 new kinds of snow cover products.Different snow cover duration days(SCD) maps are developed from these combined products.The results are as follows:(1) MODIS and AMSR-E 4-day threshold-combined snow cover product performed well in algorithm efficiency,cloud-reducing effect and capability in maintaining relatively high spatiotemporal resolutions;(2) Under all weather conditions,the overall,snow and land accuracies of the resulted cloud-free products were 96%,80% and 99%,and they were significantly higher than 64%,32% and 70% of the original MODIS Terra and Aqua combination product,respectively;(3) The SCD map generated from this product could not only maintain a high spatial resolution of the original MODIS product,but also could precisely reflect the spatial distribution of the snow cover status in the study area.%针对MODIS每日积雪产品中云覆盖现象严重这一问题,以中国干旱区作为研究对象,结合AMSR-E被动微波雪深数据,采用多时相、多传感器数据融合的方法进行去云处理,获取MODIS每日,4 d,8 d和MODIS与AM-SR-E融合后的每日,4 d与8 d共6种新的积雪产品,并分别提取其积雪持续日数(SCD)。对比结果显示,MODIS与AMSR-E多传感器的阈值法4日融合产品在融合算法效率、云去除效果和融合后保持较高分类精度方面均有较好表现,其融合后的无云产品在全天气条件下具有96%的整体分类精度、80%的雪分类精度和99%的陆地分类精度,大大高于研究区原MODIS Terra-Aqua每日融合积雪产品全天候条件下64%,32%

  11. Evaluation of monthwise and overall trends of AOD over Indian cities using MODIS Aqua and Terra retrievals

    Science.gov (United States)

    Banerjee, Subhasis; Ghosh, Sanjay

    2016-07-01

    Atmospheric aerosols have been shown to have profound impact on climate system and human health. Regular and systematic monitoring of ambient air is thus necessary in order to asses its impact. There are several ground based stations worldwide employed in this service but still their numbers are inadequate and it is even almost impossible to have such stations at difficult geographical terrains and take measurement throughout the year. Aerosol optical depth or AOD, which is a measure of extinction of incoming solar radiation, serves as proxy to atmospheric aerosol loading. Various sensors onboard different satellites take routine measurement of AOD throughout the year. Satellite based AOD is used in many studies due to their wide coverage and availability for a longer time period. Satellite measures reflected solar radiation at the top of the atmosphere. Column integrated value of aerosol are routinely estimated from those measurements using suitable inversion algorithms. MODIS instrument onboard Aqua and Terra satellites of Earth Observing System takes routine measurement in wide spectral range. We used those data to evaluate trend of AOD over almost fifty Indian cities having population more than a million. The cities we have chosen spread over almost entire length and breadth of the country. Few such studies have already been conducted using MODIS data. They typically used level 3 data. Since Level 3 data comes in 1x 1 degree gridded form they provide average value over a vast geographical region. We used level 2 dataset to enable us taking smaller region(1/2 x 1/2 degree here) centering the region of our interest . We used seasonal Mann-Kendall (M-K) statistics coupled with Sen's non-parametric slope estimation procedure to estimate monthwise and overall(i.e., yearly trend taking seasonality into account) AOD trend. We used median AOD for each month of every year to discard very high AOD's which we often get due to cloud contamination. Seasonal M-K test takes

  12. Solving the Hydration Structure of the Heaviest Actinide Aqua Ion Known: The Californium(III) Case

    Energy Technology Data Exchange (ETDEWEB)

    Den Auwer, Ch.; Guillaumont, D. [CEA Marcoule, Nucl Energy Div, Radiochem Proc Dept, SCPS LILA, 30 (France); Galbis, E.; Pappalardo, Rafael R.; Marcos Sanchez, E. [Univ Seville, Dept Quim Fis, E-41012 Seville (Spain); Hernandez-Cobos, J. [Inst Ciencias Fis, Cuernavaca 62251, Morelos (Mexico); Le Naour, C.; Simoni, E. [Univ Paris Sud, Inst Phys Nucl Orsay, Paris (France)

    2010-07-01

    In summary, the first MC simulation of the trivalent cation of californium, based on an exchangeable hydrated ion-water intermolecular potential, has been shown to extend and improve the hydrated ion model. Likewise, the CfL{sub III}-edge EXAFS spectrum of an acidic 1 mm Cf(ClO{sub 4}){sub 3} aqueous solution recorded under optimized experimental conditions has greatly improved the signal/noise ratio of the only previously recorded spectrum. The comparison of the experimental EXAFS spectrum with the two computed ones, obtained from two different intermolecular potentials that predict eight (BP86) or nine (MP2) water molecules in the first coordination shell, leads to the conclusion that the lowest hydration number is preferred. Then, as Cf{sup III} is the heaviest actinide aqua ion for which there is experimental information, the actinide contraction is supported by the present study. (For U{sup III}, R{sub U-O}=2.56 Angstroms, and CN=9{+-}1; for Pu{sup III}, R{sub Pu-O}=2.51 Angstroms and CN=9{+-}1; for Cm{sup III}, R{sub Cm-O}=2.47 Angstroms and CN=9{+-}1). The role of the second hydration shell is important in defining the structure and dynamics of the Cf{sup III} aqua ion, but the contribution of second-shell water molecules to the EXAFS signal as back-scatters is marginal. Finally, this work gives an illustrative example of the benefits which can be achieved from the combination of experimental X-ray absorption spectroscopy and computer simulations. The usefulness of the simultaneous analysis of the results as well as the importance of the structural statistical average has been clearly demonstrated herein. Each technique independently was not adequate. We believe that this study traces out a still poorly explored combined methodology which may be extremely useful for many other complexes and chemical problems. A systematic theoretical and experimental examination of the other known actinide cations on the same basis should be undertaken to confirm the

  13. The AquaVIT-1 intercomparison of atmospheric water vapor measurement techniques

    Directory of Open Access Journals (Sweden)

    D. W. Fahey

    2014-04-01

    Full Text Available The AquaVIT-1 Intercomparison of Atmospheric Water Vapor Measurement Techniques was conducted at the aerosol and cloud simulation chamber AIDA at the Karlsruhe Institute of Technology, Germany, in October 2007. The overall objective was to intercompare state-of-the-art and prototype atmospheric hygrometers with each other and with independent humidity standards under controlled conditions. This activity was conducted as a blind intercomparison with coordination by selected referees. The effort was motivated by persistent discrepancies found in atmospheric measurements involving multiple instruments operating on research aircraft and balloon platforms, particularly in the upper troposphere and lower stratosphere where water vapor reaches its lowest atmospheric values (less than 10 ppm. With the AIDA chamber volume of 84 m3, multiple instruments analyzed air with a common water vapor mixing ratio, either by extracting air into instrument flow systems, locating instruments inside the chamber, or sampling the chamber volume optically. The intercomparison was successfully conducted over 10 days during which pressure, temperature, and mixing ratio were systematically varied (50 to 500 hPa, 185 to 243 K, and 0.3 to 152 ppm. In the absence of an accepted reference instrument, the reference value was taken to be the ensemble mean of a core subset of the measurements. For these core instruments, the agreement between 10 and 150 ppm of water vapor is considered good with variation about the reference value of about ±10% (±1σ. In the region of most interest between 1 and 10 ppm, the core subset agreement is fair with variation about the reference value of ±20% (±1σ. The upper limit of precision was also derived for each instrument from the reported data. These results indicate that the core instruments, in general, have intrinsic skill to determine unknown water vapor mixing ratios with an accuracy of at least ±20%. The implication for atmospheric

  14. Detection of microcystin synthetase genes in health food supplements containing the freshwater cyanobacterium Aphanizomenon flos-aquae

    OpenAIRE

    Saker, Martin L.; Jungblut, Anne-Dorothee; Neilan, Brett A.; Rawn, Dorothea F. K.; Vasconcelos, Vitor M.

    2005-01-01

    In this study we investigated the presence of toxin-producing cyanobacterial contaminants in food supplements manufactured from blooms of the non-toxic freshwater cyanobacterium Aphanizomenon flos-aquae. Previous reports investigating the contamination of health food supplements with toxin-producing cyanobacteria have used chemical and or biochemical methods such as HPLC, ELISA and protein phosphatase assays. Whilst these studies have drawn attention to the presence of hepatotoxic microcystin...

  15. Chemical Characterization of Polysaccharide from the Slime Layer of the Cyanobacterium Microcystis flos-aquae C3-40

    OpenAIRE

    Plude, John L.; Parker, Dorothy L.; Schommer, Olivia J.; Timmerman, Robert J.; Hagstrom, Stephanie A.; Joers, James M.; Hnasko, Robert

    1991-01-01

    Macromolecular material from the slime layer of the cyanobacterium Microcystis flos-aquae C3-40 was defined as material that adhered to cells during centrifugation in growth medium but was dislodged by washing with deionized water and retained within dialysis tubing with a molecular-weight cutoff of 3,500. At each step of this isolation procedure, the slime was observed microscopically. Cells in the centrifugal pellet were surrounded by large amounts of slime that excluded negative stain, whe...

  16. Brand positioning practices in the Norwegian fishing and aqua culture industry : a comparison of brand positioning practices and normative theory

    OpenAIRE

    Onsøyen, Peder; Teslo, Øystein Strand

    2011-01-01

    This thesis is about the importance of Brand Positioning. We look at Brand Positioning with regards to how practices are within one of Norway‟s most important industries - the Norwegian Fishing- and Aqua Culture Industry. There is the first research contributing to this particular field within this industry. We based our research on three research questions. First, we wanted to present and analyze relevant Brand Positioning theory. The chosen theory is mainly based on four renowned theoris...

  17. Assessment of two aerosol optical thickness retrieval algorithms applied to MODIS Aqua and Terra measurements in Europe

    OpenAIRE

    Glantz, P.; Tesche, M

    2012-01-01

    The aim of the present study is to validate AOT (aerosol optical thickness) and Ångström exponent (α), obtained from MODIS (MODerate resolution Imaging Spectroradiometer) Aqua and Terra calibrated level 1 data (1 km horizontal resolution at ground) with the SAER (Satellite AErosol Retrieval) algorithm and with MODIS Collection 5 (c005) standard product retrievals (10 km horizontal resolution), against AERONET (AErosol RObotic NETwork) sun photometer observations over land su...

  18. Effects of Aqua Aerobics on Body Composition, Body Mass, Lipid Profile, and Blood Count in Middle-Aged Sedentary Women

    Directory of Open Access Journals (Sweden)

    Kantyka Joanna

    2015-03-01

    Full Text Available Purpose. The aim of the present investigations was to determine the effects of aqua aerobics on body weight and composition, lipid profile, and selected blood count parameters in middle-aged sedentary females. Methods. Twenty-one women were randomly assigned to an experimental group (age 56.20 ± 2.57 years, height 162.80 ± 4.76 cm, weight 74.03 ± 3.84 kg that participated in aqua aerobics classes three times a week for three months and a control group (mean age 56.44 ± 3.28 years, height 165.00 ± 3.91 cm, weight 70.01 ± 11.36 kg not involved in any kind of targeted exercise. The aqua aerobics classes were tailored to suit the age and abilities of the participants, with workout intensity controlled and maintained at approximately 128-137 bpm. Results. Significant differences between the experimental and control groups were found for body weight, total body water, fat-free mass, and skeletal muscle mass. A significant increase in post-intervention hemoglobin and erythrocyte counts was observed in the experimental group. Conclusions. Future studies should determine the intensity of physical activity with the most beneficial effect on blood variables in middle-aged and older individuals.

  19. Effect of MODIS Terra Radiometric Calibration Improvements on Collection 6 Deep Blue Aerosol Products: Validation and Terra/Aqua Consistency

    Science.gov (United States)

    Sayer, A. M.; Hsu, N. C.; Bettenhausen, C.; Jeong, M.-J.; Meister, G.

    2015-01-01

    The Deep Blue (DB) algorithm's primary data product is midvisible aerosol optical depth (AOD). DB applied to Moderate Resolution Imaging Spectroradiometer (MODIS) measurements provides a data record since early 2000 for MODIS Terra and mid-2002 for MODIS Aqua. In the previous data version (Collection 5, C5), DB production from Terra was halted in 2007 due to sensor degradation; the new Collection 6 (C6) has both improved science algorithms and sensor radiometric calibration. This includes additional calibration corrections developed by the Ocean Biology Processing Group to address MODIS Terra's gain, polarization sensitivity, and detector response versus scan angle, meaning DB can now be applied to the whole Terra record. Through validation with Aerosol Robotic Network (AERONET) data, it is shown that the C6 DB Terra AOD quality is stable throughout the mission to date. Compared to the C5 calibration, in recent years the RMS error compared to AERONET is smaller by approximately 0.04 over bright (e.g., desert) and approximately 0.01-0.02 over darker (e.g., vegetated) land surfaces, and the fraction of points in agreement with AERONET within expected retrieval uncertainty higher by approximately 10% and approximately 5%, respectively. Comparisons to the Aqua C6 time series reveal a high level of correspondence between the two MODIS DB data records, with a small positive (Terra-Aqua) average AOD offset Terra DB AOD data remain stable (to better than 0.01 AOD) throughout the mission to date, suitable for quantitative scientific analyses.

  20. Inter-satellite comparison and evaluation of Navy SNPP VIIRS and MODIS-Aqua ocean color properties

    Science.gov (United States)

    Ladner, S. D.; Arnone, R.; Vandermeulen, R.; Martinolich, P.; Lawson, A.; Bowers, J.; Crout, R.; Ondrusek, M.; Fargion, G.

    2014-05-01

    Navy operational ocean color products of inherent optical properties and radiances are evaluated for the Suomi-NPP VIIRS and MODIS-Aqua sensors. Statistical comparisons with shipboard measurements were determined in a wide variety of coastal, shelf and offshore locations in the Northern Gulf of Mexico during two cruises in 2013. Product consistency between MODIS-Aqua, nearing its end-of-life expectancy, and Suomi-NPP VIIRS is being evaluated for the Navy to retrieve accurate ocean color properties operationally from VIIRS in a variety of water types. Currently, the existence, accuracy and consistency of multiple ocean color sensors (VIIRS, MODIS-Aqua) provides multiple looks per day for monitoring the temporal and spatial variability of coastal waters. Consistent processing methods and algorithms are used in the Navy's Automated Processing System (APS) for both sensors for this evaluation. The inherent optical properties from both sensors are derived using a coupled ocean-atmosphere NIR correction extending well into the bays and estuaries where high sediment and CDOM absorption dominate the optical signature. Coastal optical properties are more complex and vary from chlorophyll-dominated waters offshore. The in-water optical properties were derived using vicariously calibrated remote sensing reflectances and the Quasi Analytical Algorithm (QAA) to derive the Inherent Optical Properties (IOP's). The Naval Research Laboratory (NRL) and the JPSS program have been actively engaged in calibration/validation activities for Visible Infrared Imager Radiometer Suite (VIIRS) ocean color products.

  1. Aqua(2,2′-bipyridine-κ2N,N′bis(thiophene-2-carboxylato-κOcopper(II

    Directory of Open Access Journals (Sweden)

    Christoph Janiak

    2009-08-01

    Full Text Available In the title complex, [Cu(C5H3O2S2(C10H8N2(H2O], the CuII atom is in a distorted square-pyramidal environment, with an Addison τ parameter of 0.07. The coordination geometry is defined by two nitrogen donors from the 2,2′-bipyridine ligand, two O atoms from two monodentate thiophene-2-carboxylate ligands and one O atom from the aqua ligand. The latter occupies the elongated apical position. This is different from the related structure of aqua(1,10-phenanthrolinebis(thiophene-2-carboxylatocopper(II where a carboxylate O atom is in the apical position [Feng et al. (2005. Z. Kristallogr. New Cryst. Struct. 220, 429–430]. The uncoordinated carboxylate O atoms form intra- and intermolecular hydrogen bonds to the aqua ligand. Two neighbouring 2,2′-bipyridine ligands form a π-stack, with a centroid–centroid distance of 3.683 (2 Å.

  2. Variability of particulate organic carbon in inland waters observed from MODIS Aqua imagery

    International Nuclear Information System (INIS)

    Surface concentrations of particulate organic carbon (POC) in shallow inland lakes were estimated using MODIS Aqua data. A power regression model of the direct empirical relationship between POC and the atmospherically Rayleigh-corrected MODIS product (Rrc,645-Rrc,1240)/(Rrc,859-Rrc,1240) was developed (R2 = 0.72, RMSE = 35.86 μgL−1, p < 0.0001, N = 47) and validated (RMSE = 44.46 μgL−1, N = 16) with field data from 56 lakes in the Middle and Lower reaches of the Yangtze River, China. This algorithm was applied to an 11 year series of MODIS data to determine the spatial and temporal distribution of POC in a wide range of lakes with different trophic and optical properties. The results indicate that there is a general increase in minimum POC concentrations in lakes from middle to lower reaches of the Yangtze River. The temporal dynamics of springtime POC in smaller lakes were found to be influenced by local meteorological conditions, in particular precipitation and wind speed, while larger lakes were found to be more sensitive to air temperature. (letter)

  3. Synthesis, properties and supramolecular structure of di(aqua)bis(ethylenediamine)nickel(II) bis(4-nitrobenzoate)

    Indian Academy of Sciences (India)

    Bikshandarkoil R Srinivasan; Gayatri K Rane

    2009-03-01

    The reaction of the sodium salt of 4-nitrobenzoic acid (4-nbaH) with [Ni(H2O)6]Cl2 or [Ni(en)3]Cl2.2H2O (en is ethylenediamine) results in the formation of the known octahedral compound [Ni(H2O)4(1-4-nba)2].2H2O (4-nba = 4-nitrobenzoate) 1 or the title compound di(aqua)bis(ethylenediamine) nickel(II) bis(4-nitrobenzoate) 2 respectively. Compounds 1 and 2 were characterized by elemental analysis, infrared spectra, DSC thermograms, weight loss studies and the structure of 2 was determined. Both 1 and 2 can be thermally decomposed to green NiO. The title compound [Ni(H2O)2(en)2](4-nba)2 2 crystallizes in the centrosymmetric monoclinic space group 21/ with the Ni(II) situated on an inversion center. The crystal structure of 2 consists of a hexacoordinated Ni(II) complex cation and an uncoordinated 4-nba anion. In the octahedral complex cation, the central metal is linked to two symmetry related bidentate en ligands and two water molecules. In the crystal structure, the cations and anions are linked by three varieties of hydrogen bonding interactions. A comparative study of seven nickel 4-nitrobenzoate compounds is described.

  4. Surface Energy Balance of Fresh and Saline Waters: AquaSEBS

    Directory of Open Access Journals (Sweden)

    Ahmed Abdelrady

    2016-07-01

    Full Text Available Current earth observation models do not take into account the influence of water salinity on the evaporation rate, even though the salinity influences the evaporation rate by affecting the density and latent heat of vaporization. In this paper, we adapt the SEBS (Surface Energy Balance System model for large water bodies and add the effect of water salinity to the evaporation rate. Firstly, SEBS is modified for fresh-water whereby new parameterizations of the water heat flux and sensible heat flux are suggested. This is achieved by adapting the roughness heights for momentum and heat transfer. Secondly, a salinity correction factor is integrated into the adapted model. Eddy covariance measurements over Lake IJsselmeer (The Netherlands are carried out and used to estimate the roughness heights for momentum (~0.0002 m and heat transfer (~0.0001 m. Application of these values over the Victoria and Tana lakes (freshwater in Africa showed that the calculated latent heat fluxes agree well with the measurements. The root mean-square of relative-errors (rRMSE is about 4.1% for Lake Victoria and 4.7%, for Lake Tana. Verification with ECMWF data showed that the salinity reduced the evaporation at varying levels by up to 27% in the Great Salt Lake and by 1% for open ocean. Our results show the importance of salinity to the evaporation rate and the suitability of the adapted-SEBS model (AquaSEBS for fresh and saline waters.

  5. Molecular Biological Study of Anti-cancer Effects of Bee Venom Aqua-acupuncture

    Directory of Open Access Journals (Sweden)

    Park Chan-Yol

    2000-07-01

    Full Text Available To study anti-cancer effect and molecular biological mechanism of bee venom for aqua-acupuncture, the effects of bee venom on cell viability and apoptosis were analyzed using MTT assay, tryphan blue assay, [3H]thymidine release assay, flow cytometric analysis, and activity of caspase-3 protease activity assay. To explore whether anti-cancer effects of bee venom are associated with the transcriptional control of gene expression, quantitative RT-PCR analysis of apoptosis-related genes was performed. The obtained results are summarized as follows: 1. The MTT assay demonstrated that cell viability was decreased by bee venom in a dose-dependant manner. 2. Significant induction of apoptosis was identified using tryphan blue assay, [3H]thymidine release assay, and flow cytometric analysis of sub G1 fraction. 3. In analysis of caspase-3 protease activity, the activity had increased significantly, in a dose-dependant manner. 4. Quantitative RT-PCR analysis of the apoptosis-related genes showed that Bcl-2 and Bcl-XL were down-regulated whereas Bax was up-regulated by bee venom treatment.

  6. Breast Support Garments are Ineffective at Reducing Breast Motion During an Aqua Aerobics Jumping Exercise.

    Science.gov (United States)

    Mills, Chris; Ayres, Bessie; Scurr, Joanna

    2015-06-27

    The buoyant forces of water during aquatic exercise may provide a form of 'natural' breast support and help to minimise breast motion and alleviate exercise induced breast pain. Six larger-breasted females performed standing vertical land and water-based jumps, whilst wearing three breast support conditions. Underwater video cameras recorded the motion of the trunk and right breast. Trunk and relative breast kinematics were calculated as well as exercised induced breast pain scores. Key results showed that the swimsuit and sports bra were able to significantly reduce the superioinferior breast range of motion by 0.04 and 0.05 m, respectively, and peak velocity by 0.23 and 0.33 m/s, respectively, during land-based jumping when compared to the bare-breasted condition, but were ineffective at reducing breast kinematics during water-based jumping. Furthermore, the magnitude of the swimsuit superioinferior breast range of motion during water-based jumping was significantly greater than land-based jumping (0.13 m and 0.06 m), yet there were no significant differences in exercise induced breast pain, thus contradicting previously published relationships between these parameters on land. Furthermore, the addition of an external breast support garment was able to reduce breast kinematics on land but not in water, suggesting the swimsuit and sports bras were ineffective and improvements in swimwear breast support garments may help to reduce excessive breast motion during aqua aerobic jumping exercises. PMID:26240648

  7. A Comparison of Cirrus Clouds Retrieved From POLDER-3/PARASOL and MODIS/Aqua

    Science.gov (United States)

    Zhang, Z.; Yang, P.; Riedi, J.; Kattawar, G.

    2007-12-01

    MODIS on board Aqua and POLDER-3 on board PARASOL are two key instruments in the A-Train constellation of satellites. MODIS has 36 spectral bands with wavelength ranging from 0.41 to 14.5 μm, but makes measurement at only one direction without information about polarization. POLDER performs multidirectional measurements, of both reflectance and polarization, at nine spectral channels (from 443 to 1020 nm). The two instruments offer different, and somehow complementary, advantages for the remote sensing of microphysical and optical properties of cirrus clouds. In this study, a comparison of cirrus clouds retrieved from the two instruments is made to obtain understanding of the possibility, advantages and limitations of synergetic retrieval. First, the comparison is made between the single scattering properties of "Inhomogeneous Hexagonal Monocrystals" (IHM) used in POLDER retrieval algorithm and the ice-crystal ensemble model used for MODIS. Substantial differences are found in the scattering phase matrix. Co-located cloud mask and cloud top height retrievals are compared, with the emphasis on high and thin cirrus clouds. The optical thicknesses of cirrus clouds retrieved by POLDER are compared with those by MODIS, with and without the constraint that the cloud effective particle size retrieved by MODIS must be similar to that of IHM.

  8. Comparison of chlorophyll in the Red Sea derived from MODIS-Aqua and in vivo fluorescence

    KAUST Repository

    Brewin, Robert J W

    2013-09-01

    The Red Sea is a unique marine environment but relatively unexplored. The only available long-term biological dataset at large spatial and temporal scales is remotely-sensed chlorophyll observations (an index of phytoplankton biomass) derived using satellite measurements of ocean colour. Yet such observations have rarely been compared with in situ data in the Red Sea. In this paper, satellite chlorophyll estimates in the Red Sea from the MODIS instrument onboard the Aqua satellite are compared with three recent cruises of in vivo fluorometric chlorophyll measurements taken in October 2008, March 2010 and September to October 2011. The performance of the standard NASA chlorophyll algorithm, and that of a new band-difference algorithm, is found to be comparable with other oligotrophic regions in the global ocean, supporting the use of satellite ocean colour in the Red Sea. However, given the unique environmental conditions of the study area, regional algorithms are likely to fare better and this is demonstrated through a simple adjustment to the band-difference algorithm. © 2013 Elsevier Inc.

  9. Breast Support Garments are Ineffective at Reducing Breast Motion During an Aqua Aerobics Jumping Exercise

    Directory of Open Access Journals (Sweden)

    Mills Chris

    2015-06-01

    Full Text Available The buoyant forces of water during aquatic exercise may provide a form of ‘natural’ breast support and help to minimise breast motion and alleviate exercise induced breast pain. Six larger-breasted females performed standing vertical land and water-based jumps, whilst wearing three breast support conditions. Underwater video cameras recorded the motion of the trunk and right breast. Trunk and relative breast kinematics were calculated as well as exercised induced breast pain scores. Key results showed that the swimsuit and sports bra were able to significantly reduce the superioinferior breast range of motion by 0.04 and 0.05 m, respectively, and peak velocity by 0.23 and 0.33 m/s, respectively, during land-based jumping when compared to the bare-breasted condition, but were ineffective at reducing breast kinematics during water-based jumping. Furthermore, the magnitude of the swimsuit superioinferior breast range of motion during water-based jumping was significantly greater than land-based jumping (0.13 m and 0.06 m, yet there were no significant differences in exercise induced breast pain, thus contradicting previously published relationships between these parameters on land. Furthermore, the addition of an external breast support garment was able to reduce breast kinematics on land but not in water, suggesting the swimsuit and sports bras were ineffective and improvements in swimwear breast support garments may help to reduce excessive breast motion during aqua aerobic jumping exercises.

  10. Impact of High Resolution SST Data on Regional Weather Forecasts

    Science.gov (United States)

    Jedlovec, Gary J.; Case, Jonathon; LaFontaine, Frank; Vazquez, Jorge; Mattocks, Craig

    2010-01-01

    Past studies have shown that the use of coarse resolution SST products such as from the real-time global (RTG) SST analysis[1] or other coarse resolution once-a-day products do not properly portray the diurnal variability of fluxes of heat and moisture from the ocean that drive the formation of low level clouds and precipitation over the ocean. For example, the use of high resolution MODIS SST composite [2] to initialize the Advanced Research Weather Research and Forecast (WRF) (ARW) [3] has been shown to improve the prediction of sensible weather parameters in coastal regions [4][5}. In an extend study, [6] compared the MODIS SST composite product to the RTG SST analysis and evaluated forecast differences for a 6 month period from March through August 2007 over the Florida coastal regions. In a comparison to buoy data, they found that that the MODIS SST composites reduced the bias and standard deviation over that of the RTG data. These improvements led to significant changes in the initial and forecasted heat fluxes and the resulting surface temperature fields, wind patterns, and cloud distributions. They also showed that the MODIS composite SST product, produced for the Terra and Aqua satellite overpass times, captured a component of the diurnal cycle in SSTs not represented in the RTG or other one-a-day SST analyses. Failure to properly incorporate these effects in the WRF initialization cycle led to temperature biases in the resulting short term forecasts. The forecast impact was limited in some situations however, due to composite product inaccuracies brought about by data latency during periods of long-term cloud cover. This paper focuses on the forecast impact of an enhanced MODIS/AMSR-E composite SST product designed to reduce inaccuracies due data latency in the MODIS only composite product.

  11. The Wavenumber-Frequency Characteristics of the Tropical Waves in an Aqua-Planet GCM

    Institute of Scientific and Technical Information of China (English)

    WANG Zaizhi; MAO Jiangyu; WU Guoxiong

    2008-01-01

    Based on the aqua-planet experiments, the wavenumber-frequency characteristics of tropical waves and their influcing factors in SST distribution and the convective parameterization scheme are investigated using the spectral atmospheric general circulation model (SAMIL). Space-time spectral analysis is used to obtain the variance of convectively coupled tropical waves. In the Control experiment with maximum SST located at the equator the simulated tropical-wave behaviors are in agreement with those in observations and theoretical solutions. When the maximum SST is located at 5°N, the symmetric and antisymmetric waves are much weaker than those in the control experiment, suggesting that tropical wave activities are very sensitive to the SST distributions. Importantly, the variance maximum of Madden-Julian oscillation (MJO) is found to occur around 5°N, which suggests that the development of the MJO depends largely on the latitude of maximum SST. Furthermore, the seasonal variations of MJO may be mainly caused by the seasonal variations of the maximum SST. The experiment results with two different cumulus schemes--the Manabe moist convective adjustment and Zhang-McFarlane (ZM) convective scheme, were also compared to examine the impacts of convective parameterization. Weakened variances of each individual tropical wave when the ZM scheme is used suggest that the ZM scheme is not favorable for the tropical wave activities. However, the wave characteristics are different when the ZM scheme is used in different models, which may imply that the simulated basic state is important to the meridional distributions of the waves. The MJO signals suggest that the parameterization scheme may have great influence on the strength, but have less direct impact on the MJO distribution. The frequency of the tropical waves may be associated with the moisture control of convection and the large-scale condensation scheme used in the model.

  12. Unmasking the 1349 earthquake source (southern Italy): paleoseismological and archaeoseismological indications from the Aquae Iuliae fault

    Science.gov (United States)

    Galli, Paolo Antonio Costantino; Naso, José Alfredo

    2009-02-01

    The 9th September, 1349, earthquake was one of the most catastrophic events experienced along the Apennines. At least three main shocks struck a vast area of the Molise-Latium-Abruzzi regions, and damage was even sustained by the distant monumental buildings of Rome. The southern-most shock (Mw ˜ 6.7) occurred at the border between southern Latium and western Molise, razing to the ground the towns of Isernia, Venafro and Cassino, amongst others, and devastating Montecassino Abbey. As with other Medieval catastrophic sequences (e.g., in December 1456, Mw ˜ 6.5-7.0), this earthquake has not yet been associated to any seismogenic source; thus, it still represents a thorn in the flesh of earthquake geologists. We have here carried out a reappraisal of the effects of this earthquake, and through an interpretation of aerial photographs and a field survey, we have carried out paleoseismological analyses across a poorly known, ˜N130 normal fault that crosses the Molise-Campania border. This structure showed repeated surface ruptures during the late Holocene, the last one of which fits excellently with the 1349 event, both in terms of the dating and the rupture dimension. On the other hand, archaeoseismic analyses have also indicated the faulting of an Augustean aqueduct. The amount of apparent offset of the aqueduct across the fault traces shows that there were other surface faulting event(s) during the Roman-High Middle-Age period. Therefore, in trying to ascertain whether these events were associated with known (potentially of 346 AD or 848 AD), or unknown earthquakes in the area, it became possible that this ˜20-km-long fault (here named the Aquae Iuliae fault) is characterized by high slip rates and a short recurrence time. This is in agreement with both the similar behaviour of the neighbouring northern Matese fault system, and with recent GPS analyses showing unexpectedly high extension rates in this area.

  13. Modeling and Mapping Oyster Norovirus Outbreak Risks in Gulf of Mexico Using NASA MODIS Aqua Data

    Science.gov (United States)

    Deng, Z.; Wang, J.

    2015-12-01

    Norovirus is a highly infectious virus and the leading cause of foodborne disease outbreaks such as oyster norovirus outbreaks. Currently, there is no vaccine to prevent norovirus infection and no drug to treat it. This paper presents an integrated modeling and mapping framework for predicting the risk of norovirus outbreaks in oyster harvesting waters in the Northern Gulf of Mexico coast. The framework involves (1) the construction of three novel remote sensing algorithms for the retrieval of sea surface salinity, sea surface temperature, and gage height (tide level) using NASA MODIS Aqua data; (2) the development of probability-based Artificial Neural Network (ANN) model for the prediction of oyster norovirus outbreak risk, and (3) the application of the Local Indicators of Spatial Association (LISA) for mapping norovirus outbreak risks in oyster harvesting areas in the Northern Gulf of Mexico using the remotely sensed NASA data, retrieved data from the three remote sensing algorithms, and the ANN model predictions. The three remote sensing algorithms are able to correctly retrieve 94.1% of sea surface salinity, 94.0% of sea surface temperature, and 77.8% of gage height observed along the US coast, including the Pacific coast, the Gulf of Mexico coast, and the Atlantic coast. The gage height, temperature, and salinity are the three most important explanatory variables of the ANN model in terms of spatially distributed input variables. The ANN model is capable of hindcasting/predicting all oyster norovirus outbreaks occurred in oyster growing areas along the Gulf of Mexico coast where environmental data are available. The integrated modeling and mapping framework makes it possible to map daily risks of norovirus outbreaks in all oyster harvesting waters and particularly the oyster growing areas where no in-situ environmental data are available, greatly improving the safety of seafood and reducing outbreaks of foodborne disease.

  14. Effect of Saffron aqua Extract on Angiogenesis in Chick Chorioalantoic Membrane

    Directory of Open Access Journals (Sweden)

    Javad Baharara

    2014-03-01

    Full Text Available Background: Studies confirmed anticancer properties of saffron extract. Angiogenesis, formation of new blood vessels which is necessary in many physiological stages and pathological events such as tumor growth. So it would be an effective strategy to inhibit angiogenesis to treat many cancers and metastasis. In this experimental study, effects of saffron on angiogenesis in chick chorioalantoic membrane (CAM were investigated. Materials and Methods: Fifity ross fertilized eggs divided in 5 groups, including: control, sham exposed, experimental group 1, 2 and 3. In second day of incubation window was opened on eggs. In day 8 gelatin sponges contain gelatin and albumin was put on chorioalantoic membrane and was soaked with Saffron aqua extract in concentration 100, 400 and 800 μg/ml. In 12th day all cases were photographed by photo stereomicroscope. Numbers and lengths of vessels around the sponges were measured by Image J software. Data were analyzed with SPSS-16 in significant level p<0.05. Results: According to data analysis, changes had no correlation on the average length of blood vessels in the first experimental group (41.5±5.5 mm, compared with the control group, (44.5±2.4 mm. While in the second and third experimental group (40.2±2.1 mm and (38.4±3.8 mm these changes were significant (p=0.001. On the other hand, the average number of blood vessels in the first experimental group (22.07±5.2 in compare with the control group (27.46±4.4 shows a significant reduction (p=0.02, this decline between the second (18.80±4.4 and third (15.87±3.8 experimental groups was significant at the level of p=0.001. Conclusion: Saffron extract has a dose dependent inhibitory effect on angiogenesis in chick chorioalantoic membrane.

  15. MODIS-Aqua detects Noctiluca scintillans and hotspots in the central Arabian Sea.

    Science.gov (United States)

    Dwivedi, R; Priyaja, P; Rafeeq, M; Sudhakar, M

    2016-01-01

    Northern Arabian Sea is considered as an ecologically sensitive area as it experiences a massive upwelling and long-lasting algal bloom, Noctiluca scintillans (green tide) during summer and spring-winter, respectively. Diatom bloom is also found to be co-located with N. scintillans and both have an impact on ecology of the basin. In-house technique of detecting species of these blooms from Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua data was used to generate a time-series of images revealing their spatial distribution. A study of spatial-temporal variability of these blooms using satellite data expressed a cyclic pattern of their spread over a period of 13 years. An average distribution of the blooms for January-March period revealed a peak in 2015 and minimum in 2013. Subsequently, a time-series of phytoplankton species images were generated for these 2 years to study their inter-annual variability and the associated factors. Species images during active phase of the bloom (February) in 2015 indicated development of N. scintillans and diatom in the central Arabian Sea also, up to 12° N. This observation was substantiated with relevant oceanic parameters measured from the ship as well as satellite data and the same is highlight of the paper. While oxygen depletion and release of ammonia associated with N. scintillans are detrimental for waters on the western side; it is relatively less extreme and supports the entire food chain on the eastern side. In view of these contrasting eco-sensitive events, it is a matter of concern to identify biologically active persistent areas, hot spots, in order to study their ecology in detail. An ecological index, persistence of the bloom, was derived from the time-series of species images and it is another highlight of our study. PMID:26690080

  16. Effects of nutrient loading on Anabaena flos-aquae biofilm: biofilm growth and nutrient removals.

    Science.gov (United States)

    Li, Xiaowei; Wei, Qun; Tu, Xiaojie; Zhu, Yuxuan; Chen, Yanfei; Guo, Lina; Zhou, Jun; Sun, Hongyun

    2016-01-01

    Effects of three different nutrient loadings (low nutrient loading, medium nutrient loading and high nutrient loading, denoted as LNS, MNS and HNS, respectively) on the structure and functions of algal biofilm using Anabaena flos-aquae were investigated using synthetic wastewater. Nutrients removal efficiencies, biofilm thickness, microalgae dehydrogenase activity (DHA) and exopolysaccharide (EPS) productions were examined. Results showed that the changes of nutrient concentration were insignificant after 4 days of experiment for the case of HNS condition; 9 days for the case of MNS condition, and 6 days for the case of LNS condition, respectively. The biofilm thickness, nutrient removal efficiencies, algae DHA and EPS productions increased with the increase of nutrient loadings in synthetic wastewater. For the case of HNS condition, the microalgal biofilm exhibited the best performance in terms of C, N and P removal efficiencies, reaching the removal rates of 68.45, 3.56 and 1.61 mg·L(-1)·d(-1) for C, N, P, respectively. This was likely because, fact with the high nutrient loading, the high biological activity could be achieved, thus resulting in high nutrient removals. The thickness of the biofilm in HNS condition was 75 μm, which was closely related to EPS production. DHA and EPS concentrations were 7.24 and 1.8 × 10(-2) mg·mm(-2), respectively. It was also shown that apart from the nutrient loading, the structure and functions of microalgal biofilm were also influenced by other factors, such as illumination and temperature. PMID:27438243

  17. AquaCrop模型对旱区冬小麦抗旱灌溉的模拟研究%Winter Wheat Irrigation Simulation in Arid Area Based on AquaCrop Model

    Institute of Scientific and Technical Information of China (English)

    滕晓伟; 董燕生; 沈家晓; 孟鲁闽; 冯海宽

    2015-01-01

    Objective] It is important to take an irrigation measure in time according to the drought situation in resisting drought and improving water use efficiency. In view of practical field application, this study explores the applicability in arid area and irrigation simulation in drought year with AquaCrop model. It will provide a guideline in resisting drought and protecting the yield.[Method] Field surveys and experiments were conducted at Rougu test area and Wugong test area, Shaanxi Province during the typical wheat growing seasons of 2012-2013 and 2013-2014.The model parameters were adjusted with the data of Rougu test area acquired in 2013-2014, and the model was validated with the data acquired in Rougu test area in 2012-2013 and Wugong test area in 2013-2014. The model parameters mainly include canopy growth and canopy senescence coefficient, maximum canopy cover, water productivity and reference harvest coefficient. According to the surveys of the factual irrigation situation in 2012-2013, four irrigation situations were developed to simulate their influence on biomass and yield. Consequently, the optimal irrigation strategy was obtained. Finally, the water use efficiency was calculated.[Result]The R2and RMSE between the simulated and the measured canopy cover were 0.464 and 8.0%, respectively. The R2 and RMSE of simulated and measured biomass were 0.889 and 1.662 t·ha-1, respectively. The RMSE of simulated yield and measured yield was 0.377 t·ha-1.Underthetwo scenarios that the wheat was irrigated at the 77th day and the 172th day after planting, the largest biomass could be obtained. The highest yield approaching 6.451 t·ha-1 could be obtained under thetreatment that the wheat was irrigated on the 77th day, the 172th day and the 200th day after planting. The water use efficiencies of Rougu test area (from 2012 to 2013), Rougu test area (from 2013 to 2014) and Wugong test area (from 2013 to 2014) were 1.84, 1.69 and 1.82 kg·m-3, respectively

  18. Effect of MODIS Terra radiometric calibration improvements on Collection 6 Deep Blue aerosol products: Validation and Terra/Aqua consistency

    Science.gov (United States)

    Sayer, A. M.; Hsu, N. C.; Bettenhausen, C.; Jeong, M.-J.; Meister, G.

    2015-12-01

    The Deep Blue (DB) algorithm's primary data product is midvisible aerosol optical depth (AOD). DB applied to Moderate Resolution Imaging Spectroradiometer (MODIS) measurements provides a data record since early 2000 for MODIS Terra and mid-2002 for MODIS Aqua. In the previous data version (Collection 5, C5), DB production from Terra was halted in 2007 due to sensor degradation; the new Collection 6 (C6) has both improved science algorithms and sensor radiometric calibration. This includes additional calibration corrections developed by the Ocean Biology Processing Group to address MODIS Terra's gain, polarization sensitivity, and detector response versus scan angle, meaning DB can now be applied to the whole Terra record. Through validation with Aerosol Robotic Network (AERONET) data, it is shown that the C6 DB Terra AOD quality is stable throughout the mission to date. Compared to the C5 calibration, in recent years the RMS error compared to AERONET is smaller by ˜0.04 over bright (e.g., desert) and ˜0.01-0.02 over darker (e.g., vegetated) land surfaces, and the fraction of points in agreement with AERONET within expected retrieval uncertainty higher by ˜10% and ˜5%, respectively. Comparisons to the Aqua C6 time series reveal a high level of correspondence between the two MODIS DB data records, with a small positive (Terra-Aqua) average AOD offset radiometric calibration efforts and that the C6 MODIS Terra DB AOD data remain stable (to better than 0.01 AOD) throughout the mission to date, suitable for quantitative scientific analyses.

  19. The AquaDEB project: Physiological flexibility of aquatic animals analysed with a generic dynamic energy budget model (phase II)

    Science.gov (United States)

    Alunno-Bruscia, Marianne; van der Veer, Henk W.; Kooijman, Sebastiaan A. L. M.

    2011-11-01

    This second special issue of the Journal of Sea Research on development and applications of Dynamic Energy Budget (DEB) theory concludes the European Research Project AquaDEB (2007-2011). In this introductory paper we summarise the progress made during the running time of this 5 years' project, present context for the papers in this volume and discuss future directions. The main scientific objectives in AquaDEB were (i) to study and compare the sensitivity of aquatic species (mainly molluscs and fish) to environmental variability within the context of DEB theory for metabolic organisation, and (ii) to evaluate the inter-relationships between different biological levels (individual, population, ecosystem) and temporal scales (life cycle, population dynamics, evolution). AquaDEB phase I focussed on quantifying bio-energetic processes of various aquatic species ( e.g. molluscs, fish, crustaceans, algae) and phase II on: (i) comparing of energetic and physiological strategies among species through the DEB parameter values and identifying the factors responsible for any differences in bioenergetics and physiology; (ii) considering different scenarios of environmental disruption (excess of nutrients, diffuse or massive pollution, exploitation by man, climate change) to forecast effects on growth, reproduction and survival of key species; (iii) scaling up the models for a few species from the individual level up to the level of evolutionary processes. Apart from the three special issues in the Journal of Sea Research — including the DEBIB collaboration (see vol. 65 issue 2), a theme issue on DEB theory appeared in the Philosophical Transactions of the Royal Society B (vol 365, 2010); a large number of publications were produced; the third edition of the DEB book appeared (2010); open-source software was substantially expanded (over 1000 functions); a large open-source systematic collection of ecophysiological data and DEB parameters has been set up; and a series of DEB

  20. Ways of introduction of aqua aerobics in lessons on swimming of students of unathletic institutes of higher

    OpenAIRE

    Болтєнкова / Boltenkova O., О. М.

    2012-01-01

    The questions of including of elements of aqua aerobics are examined in lessons on swimming of students of І and ІІ courses. A role and place of exercises open up on a aerobics on water in the structure of teaching of students to swimming, basic rich in content descriptions over of lessons are brought. The stages over of introduction of elements of aerobics on water are brought in lessons on swimming. Facilities of forming of basic motive internalss are specified during realization of employm...

  1. On-orbit performance and calibration improvements for the reflective solar bands of Terra and Aqua MODIS

    Science.gov (United States)

    Angal, Amit; Xiong, Xiaoxiong (Jack); Wu, Aisheng; Chen, Hongda; Geng, Xu; Link, Daniel; Li, Yonghong; Wald, Andrew; Brinkmann, Jake

    2016-05-01

    Moderate Resolution Imaging Spectroradiometer (MODIS) is the keystone instrument for NASA's EOS Terra and Aqua missions, designed to extend and improve heritage sensor measurements and data records of the land, oceans and atmosphere. The reflective solar bands (RSB) of MODIS covering wavelengths from 0.41 μm to 2.2 μm, are calibrated on-orbit using a solar diffuser (SD), with its on-orbit bi-directional reflectance factor (BRF) changes tracked using a solar diffuser stability monitor (SDSM). MODIS is a scanning radiometer using a two-sided paddle-wheel mirror to collect earth view (EV) data over a range of +/-55° off instrument nadir. In addition to the solar calibration provided by the SD and SDSM system, lunar observations at nearly constant phase angles are regularly scheduled to monitor the RSB calibration stability. For both Terra and Aqua MODIS, the SD and lunar observations are used together to track the on-orbit changes of RSB response versus scan angle (RVS) as the SD and SV port are viewed at different angles of incidence (AOI) on the scan mirror. The MODIS Level 1B (L1B) Collection 6 (C6) algorithm incorporated several enhancements over its predecessor Collection 5 (C5) algorithm. A notable improvement was the use of the earth-view (EV) response trends from pseudo-invariant desert targets to characterize the on-orbit RVS for select RSB (Terra bands 1-4, 8, 9 and Aqua bands 8, 9) and the time, AOI, and wavelength-dependent uncertainty. The MODIS Characterization Support Team (MCST) has been maintaining and enhancing the C6 algorithm since its first update in November, 2011 for Aqua MODIS, and February, 2012 for Terra MODIS. Several calibration improvements have been incorporated that include extending the EV-based RVS approach to other RSB, additional correction for SD degradation at SWIR wavelengths, and alternative approaches for on-orbit RVS characterization. In addition to the on-orbit performance of the MODIS RSB, this paper also discusses in

  2. Evaluación de la calidad en uso de sitios web asistida por software: sw aqua

    OpenAIRE

    MORENO S., MARIO R.; GONZÁLEZ C., GABRIEL U.; ECHARTEA C., DIANA C.

    2009-01-01

    En este artículo se describe el desarrollo de una herramienta para la evaluación de la calidad en uso de sitios web basada en el estándar ISO/IEC 91264. La herramienta permite obtener al evaluador las métricas de la calidad en uso descritas en el estándar. Los resultados de la evaluación están basados en cuatro características: efectividad, productividad, seguridad y satisfacción. La herramienta de SW-AQUA fue desarrollada siguiendo la metodología del proceso unificado de desarrollo de sof...

  3. AquaResp® - free open-source software for measuring oxygen consumption of resting aquatic animals

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2012-01-01

    Soc for experimental Biol Annual Meeting - Salzburg 2012 Morten Bo S. Svendsen (University of Copenhagen, Denmark), Peter V. Skov (Technical University of Denmark, Denmark), Peter G .Bushnell (Indiana University South Bend, Indiana) and John F. Steffensen (University of Copenhagen, Denmark) Aqua......Resp" is a free open-source software program developed to measure the oxygen consumption of aquatic animals using intermittent flow techniques. This free program is based on Microsoft Excel, and uses the MCC Universal Library and a data acquisition board to acquire analogue readings from up to four input ports...

  4. Land Surface Microwave Emissivity Dynamics: Observations, Analysis and Modeling

    Science.gov (United States)

    Tian, Yudong; Peters-Lidard, Christa D.; Harrison, Kenneth W.; Kumar, Sujay; Ringerud, Sarah

    2014-01-01

    Land surface microwave emissivity affects remote sensing of both the atmosphere and the land surface. The dynamical behavior of microwave emissivity over a very diverse sample of land surface types is studied. With seven years of satellite measurements from AMSR-E, we identified various dynamical regimes of the land surface emission. In addition, we used two radiative transfer models (RTMs), the Community Radiative Transfer Model (CRTM) and the Community Microwave Emission Modeling Platform (CMEM), to simulate land surface emissivity dynamics. With both CRTM and CMEM coupled to NASA's Land Information System, global-scale land surface microwave emissivities were simulated for five years, and evaluated against AMSR-E observations. It is found that both models have successes and failures over various types of land surfaces. Among them, the desert shows the most consistent underestimates (by approx. 70-80%), due to limitations of the physical models used, and requires a revision in both systems. Other snow-free surface types exhibit various degrees of success and it is expected that parameter tuning can improve their performances.

  5. Remote sensing of an agricultural soil moisture network in Walnut Creek, Iowa

    Science.gov (United States)

    Cosh, M. H.; Prueger, J. H.; Goodman, F.; Jackson, T. J.

    2009-12-01

    The calibration and validation of soil moisture remote sensing products is complicated by the logistics of installing a soil moisture network for a long term period in an active landscape. Usually soil moisture sensors are added to existing precipitation networks which have as a singular requirement a full sky view to be representative of the location. Therefore, these stations are located along field boundaries or in non-representative sites with regards to soil type or soil moisture. Landowners are also less willing to sacrifice productive acreage within their fields for scientific monitoring without compensation. A solution has been developed in the Walnut Creek watershed near Ames, Iowa. Small temporary soil moisture stations are installed within the corn and soybean fields which dominate the landscape. Land owners and operators are able to move the stations if necessary, such as during planting and harvesting or field tillage. This network design results in a non-continuous, but representative watershed average. Begun in 2006, nine stations have been recording the surface soil moisture (~5 cm), which is commonly used in the validation of the AMSR-E instrument. The temporal stability of this network is evaluated and inter-seasonal consistency is addressed. A comparison is also made of the remote sensing products from AMSR-E and the Walnut Creek network during its deployment. It is expected that this network will continue to support soil moisture remote sensing into the future, including the SMOS and SMAP satellite missions.

  6. A study on the dynamic tie points ASI algorithm in the Arctic Ocean

    Institute of Scientific and Technical Information of China (English)

    HAO Guanghua; SU Jie

    2015-01-01

    Sea ice concentration is an important parameter for polar sea ice monitoring. Based on 89 GHz AMSR-E (Advanced Microwave Scanning Radiometer for Earth Observing System) data, a gridded high-resolution passive microwave sea ice concentration product can be obtained using the ASI (the Arctic Radiation And Turbulence Interaction Study (ARTIST) Sea Ice) retrieval algorithm. Instead of using fixed-point values, we developed ASI algorithm based on daily changed tie points, called as the dynamic tie point ASI algorithm in this study. Here the tie points are expressed as the brightness temperature polarization difference of open water and 100% sea ice. In 2010, the yearly-averaged tie points of open water and sea ice in Arctic are estimated to be 50.8 K and 7.8 K, respectively. It is confirmed that the sea ice concentrations retrieved by the dynamic tie point ASI algorithm can increase (decrease) the sea ice concentrations in low-value (high-value) areas. This improved the sea ice concentrations by present retrieval algorithm from microwave data to some extent. Comparing with the products using fixed tie points, the sea ice concentrations retrieved from AMSR-E data by using the dynamic tie point ASI algorithm are closer to those obtained from MODIS (Moderate-resolution Imaging Spectroradiometer) data. In 40 selected cloud-free sample regions, 95% of our results have smaller mean differences and 75% of our results have lower root mean square (RMS) differences compare with those by the fixed tie points.

  7. Sea surface wind speed estimation from space-based lidar measurements

    Directory of Open Access Journals (Sweden)

    Y. Hu

    2008-02-01

    Full Text Available Global satellite observations of lidar backscatter measurements acquired by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO mission and collocated sea surface wind speed data from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E, are used to investigate the relation between wind driven wave slope variance and sea surface wind speed. The new slope variance – wind speed relation established from this study is similar to the linear relation from Cox-Munk (1954 and the log-linear relation from Wu (1972, 1990 for wind speed larger than 7 m/s and 13.3 m/s, respectively. For wind speed less than 7 m/s, the slope variance is proportional to the square root of the wind speed, assuming a two dimensional isotropic Gaussian wave slope distribution. This slope variance – wind speed relation becomes linear if a one dimensional Gaussian wave slope distribution is assumed. Contributions from whitecaps and subsurface backscattering are effectively removed by using 532 nm lidar depolarization measurements. This new slope variance – wind speed relation is used to derive sea surface wind speed from CALIPSO single shot lidar measurements (70 m spot size, after correcting for atmospheric attenuation. The CALIPSO wind speed result agrees with the collocated AMSR-E wind speed, with 1.2 m/s rms error.

  8. Source analysis of spaceborne microwave radiometer interference over land

    Science.gov (United States)

    Guan, Li; Zhang, Sibo

    2016-03-01

    Satellite microwave thermal emissions mixed with signals from active sensors are referred to as radiofrequency interference (RFI). Based on Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) observations from June 1 to 16, 2011, RFI over Europe was identified and analyzed using the modified principal component analysis algorithm in this paper. The X band AMSR-E measurements in England and Italy are mostly affected by the stable, persistent, active microwave transmitters on the surface, while the RFI source of other European countries is the interference of the reflected geostationary TV satellite downlink signals to the measurements of spaceborne microwave radiometers. The locations and intensities of the RFI induced by the geostationary TV and communication satellites changed with time within the observed period. The observations of spaceborne microwave radiometers in ascending portions of orbits are usually interfered with over European land, while no RFI was detected in descending passes. The RFI locations and intensities from the reflection of downlink radiation are highly dependent upon the relative geometry between the geostationary satellite and the measuring passive sensor. Only these fields of view of a spaceborne instrument whose scan azimuths are close to the azimuth relative to the geostationary satellite are likely to be affected by RFI.

  9. Evaluation of Satellite and Reanalysis Soil Moisture Products over Southwest China Using Ground-Based Measurements

    Directory of Open Access Journals (Sweden)

    Jian Peng

    2015-11-01

    Full Text Available Long-term global satellite and reanalysis soil moisture products have been available for several years. In this study, in situ soil moisture measurements from 2008 to 2012 over Southwest China are used to evaluate the accuracy of four satellite-based products and one reanalysis soil moisture product. These products are the Advanced Microwave Scanning Radiometer for the Earth observing system (AMSR-E, the Advanced Scatterometer (ASCAT, the Soil Moisture and Ocean Salinity (SMOS, the European Space Agency’s Climate Change Initiative soil moisture (CCI SM, and the European Centre for Medium-Range Weather Forecasts (ECMWF Interim Reanalysis (ERA-Interim. The evaluation of soil moisture absolute values and anomalies shows that all the products can capture the temporal dynamics of in situ soil moisture well. For AMSR-E and SMOS, larger errors occur, which are likely due to the severe effects of radio frequency interference (RFI over the test region. In general, the ERA-Interim (R = 0.782, ubRMSD = 0.035 m3/m3 and CCI SM (R = 0.723, ubRMSD = 0.046 m3/m3 perform the best compared to the other products. The accuracy levels obtained are comparable to validation results from other regions. Therefore, local hydrological applications and water resource management will benefit from the long-term ERA-Interim and CCI SM soil moisture products.

  10. Source analysis of spaceborne microwave radiometer interference over land

    Institute of Scientific and Technical Information of China (English)

    Li GUAN; Sibo ZHANG

    2016-01-01

    Satellite microwave thermal emissions mixed with signals from active sensors are referred to as radiofrequency interference (RFI).Based on Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) observations from June 1 to 16,2011,RFI over Europe was identified and analyzed using the modified principal component analysis algorithm in this paper.The X band AMSR-E measurements in England and Italy are mostly affected by the stable,persistent,active microwave transmitters on the surface,while the RFI source of other European countries is the interference of the reflected geostationary TV satellite downlink signals to the measurements of spaceborne microwave radiometers.The locations and intensities of the RFI induced by the geostationary TV and communication satellites changed with time within the observed period.The observations of spacebome microwave radiometers in ascending portions of orbits are usually interfered with over European land,while no RFI was detected in descending passes.The RFI locations and intensities from the reflection of downlink radiation are highly dependent upon the relative geometry between the geostationary satellite and the measuring passive sensor.Only these fields of view of a spacebome instrument whose scan azimuths are close to the azimuth relative to the geostationary satellite are likely to be affected by RFI.

  11. One of the Possible Causes for Diatom Appearance in Ariake Bay Area in Japan In the Winter from 2010 to 2015 (Clarified with AQUA/MODIS

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2016-10-01

    Full Text Available One of the possible causes for diatom appearance in Ariake bay area I Japan in the winter seasons from 2010 to 2015 is clarified with AQUA/MODIS of remote sensing satellite. Two months (January and February AQUA/MODIS derived chlorophyll-a concentration are used for analysis of diatom appearance. Match-up data of AQUA/MODIS with the evidence of the diatom appearance is extracted from the MODIS database. Through experiments, it is found that diatom appears after a long period time of relatively small size of red tide appearance. Also, it depends on the weather conditions and tidal effect as well as water current in the bay area in particular.

  12. The Aqua-planet Experiment (APE): Response to Changed Meridional SST Profile

    Science.gov (United States)

    Williamson, David L.; Blackburn, Michael; Nakajima, Kensuke; Ohfuchi, Wataru; Takahashi, Yoshiyuki O.; Hayashi, Yoshi-Yuki; Nakamura, Hisashi; Ishiwatari, Masaki; Mcgregor, John L.; Borth, Hartmut; Wirth, Volkmar; Frank, Helmut; Bechtold, Peter; Wedi, Nils P.; Tomita, Hirofumi; Satoh, Masaki; Zhao, Ming; Held, Isaac M.; Suarez, Max J.; Lee, Myong-In; Watanabe, Masahiro; Kimoto, Masahide; Liu, Yimin; Wang, Zaizhi; Molod, Andrew; RajenDran, Kavirajan; Kitoh, Akio; Stratton, Rachel

    2013-01-01

    This paper explores the sensitivity of Atmospheric General Circulation Model (AGCM) simulations to changes in the meridional distribution of sea surface temperature (SST). The simulations are for an aqua-planet, a water covered Earth with no land, orography or sea- ice and with specified zonally symmetric SST. Simulations from 14 AGCMs developed for Numerical Weather Prediction and climate applications are compared. Four experiments are performed to study the sensitivity to the meridional SST profile. These profiles range from one in which the SST gradient continues to the equator to one which is flat approaching the equator, all with the same maximum SST at the equator. The zonal mean circulation of all models shows strong sensitivity to latitudinal distribution of SST. The Hadley circulation weakens and shifts poleward as the SST profile flattens in the tropics. One question of interest is the formation of a double versus a single ITCZ. There is a large variation between models of the strength of the ITCZ and where in the SST experiment sequence they transition from a single to double ITCZ. The SST profiles are defined such that as the equatorial SST gradient flattens, the maximum gradient increases and moves poleward. This leads to a weakening of the mid-latitude jet accompanied by a poleward shift of the jet core. Also considered are tropical wave activity and tropical precipitation frequency distributions. The details of each vary greatly between models, both with a given SST and in the response to the change in SST. One additional experiment is included to examine the sensitivity to an off-equatorial SST maximum. The upward branch of the Hadley circulation follows the SST maximum off the equator. The models that form a single precipitation maximum when the maximum SST is on the equator shift the precipitation maximum off equator and keep it centered over the SST maximum. Those that form a double with minimum on the equatorial maximum SST shift the double

  13. AquaUsers: Improving access to remotely sensed data for non-specialists

    Science.gov (United States)

    Clements, Oliver; Walker, Peter; Calton, Ben; Miller, Peter

    2015-04-01

    In recent years more and more complex remotely sensed data have been made available to the public by national and international agencies. These data are also reprocessed by different organisations to produce secondary products that are of specific need to a community. For instance the production of chlorophyll concentration maps from ocean colour data provided by NASA for the marine community. Providing access to such data has normally been focused on simply making the data available with appropriate metadata so that domain specialists can make use of it. One area that has seen significant investment, both of time and money, has been in the production of web based data portals. Primarily these have focused on spatial data. By providing a web map visualisation users are able to quickly assess both spatial coverage and data values. Data portal improvements have been possible thanks to advancements in back end data servers such as Thredds and ncWMS as well as improvements in front-end libraries for data visualisation including OpenLayers and D3. Data portals that make use of these technological advancements have aimed at improving the access and use of data by trained scientific domain specialists. There is now a push to improve access to these systems by non-scientific domain specialists through several European Commission funded projects, including OPEC and AquaUsers. These projects have improved upon an open source web GIS portal created by Plymouth Marine Laboratory [https://github.com/pmlrsg/GISportal]. We will present the latest version of our GIS portal, discuss the designs steps taken to achieve the latest build and share user stories as to how non-domain specialists are now able to utilise the system and get benefits from remotely sensed data. A first version was produced and disseminated to end users for feedback. At this stage the end users included government advisors, fish farmers and scientific groups with no specific GIS training or knowledge. This

  14. Small vs. Large Convective Cloud Objects from CERES Aqua Observations: Where are the Intraseasonal Variation Signals?

    Science.gov (United States)

    Xu, Kuan-Man

    2016-01-01

    During inactive phases of Madden-Julian oscillation (MJO), there are plenty of deep but small convective systems and far fewer deep and large ones. During active phases of MJO, a manifestation of an increase in the occurrence of large and deep cloud clusters results from an amplification of large-scale motions by stronger convective heating. This study is designed to quantitatively examine the roles of small and large cloud clusters during the MJO life cycle. We analyze the cloud object data from Aqua CERES observations for tropical deep convective (DC) and cirrostratus (CS) cloud object types according to the real-time multivariate MJO index. The cloud object is a contiguous region of the earth with a single dominant cloud-system type. The size distributions, defined as the footprint numbers as a function of cloud object diameters, for particular MJO phases depart greatly from the combined (8-phase) distribution at large cloud-object diameters due to the reduced/increased numbers of cloud objects related to changes in the large-scale environments. The medium diameter corresponding to the combined distribution is determined and used to partition all cloud objects into "small" and "large" groups of a particular phase. The two groups corresponding to the combined distribution have nearly equal numbers of footprints. The medium diameters are 502 km for DC and 310 km for cirrostratus. The range of the variation between two extreme phases (typically, the most active and depressed phases) for the small group is 6-11% in terms of the numbers of cloud objects and the total footprint numbers. The corresponding range for the large group is 19-44%. In terms of the probability density functions of radiative and cloud physical properties, there are virtually no differences between the MJO phases for the small group, but there are significant differences for the large groups for both DC and CS types. These results suggest that the intreseasonal variation signals reside at the

  15. Calibration and Validation of AquaCrop Model in Spring Wheat Region of Songnen Plain%AquaCrop作物模型在松嫩平原春麦区的校正和验证

    Institute of Scientific and Technical Information of China (English)

    付驰; 李双双; 李晶; 王泳超; 芦玉双; 许为政; 魏湜

    2012-01-01

    In this study,the measured soil moisture,spring wheat growth and yield data,combined with meteorological data obtained AquaCrop soil moisture and spring wheat growth simulation model parameters,and previous years' data for the crop model validation.The results showed that the simulated values and measured values of spring wheat's yield and biomass MAE were 0.058 and 0.109,RMSE were 0.06 and 0.11 t/hm2,EF were 0.795 and 0.822,CRM were-0.006 96 and 0.005 87,IoA were 0.959 and 0.966;for 10 cm and 20 cm in depth soil volumetric water content of the simulated values and measured values,MAE were 5.23 and 2.53,RMSE were 6.47% and 7.95%,EF were-0.277 and-0.069,CRM were 0.097 and 0.212,IoA were 0.585 and 0.741.AquaCrop model of biomass and yield of spring wheat growth stages and soil volumetric water content of the simulation results is fine,the production of spring wheat Songnen Plain has some reference value.%为了研究AquaCrop作物模型在松嫩平原春麦区的适用性,利用实测的土壤水分、春小麦生长和产量数据,结合气象数据,获得AquaCrop模拟土壤水分和春小麦生长的模型参数,并用往年的作物生长数据对模型进行验证。结果表明,春小麦的产量和生物量的实测值与模拟值的绝对平均误差(MAE)为0.058和0.109、均方根误差(RMSE)为0.06和0.11t/hm2、模拟性能指数(EF)为0.795和0.822、残差聚集系数(CRM)为-0.006 96和0.005 87、一致性系数(IoA)为0.959和0.966;对10cm和20cm土壤体积含水率的实测值与模拟值的MAE为5.23和2.53、RMSE为6.47%和7.95%、EF为-0.277和-0.069、CRM为0.097和0.212、IoA为0.585和0.741。说明AquaCrop模型对春小麦的生物量和产量及生育期土壤体积含水率的模拟结果总体较好,对松嫩平原春麦生产有一定的参考意义。

  16. Kinetics and equilibria for the axial ligation of bromomethyl (aqua)cobaloxime with pyridines - Isolation characterization and DNA binding

    Indian Academy of Sciences (India)

    Kotha Laxma Reddy; K Ashwini Kumar; N Ravi Kumar Reddy; Penumaka Nagababu; A Panasa Reddy; S Satyanarayana

    2009-11-01

    The kinetics and equilibria for the axial ligation of pyridine and substituted pyridines to bromomethyl(aqua)cobaloxime have been measured spectrophotometrically in aqueous solutions of ionic strength 1.0 M (KC1) at 25°C as a function of H. The binding constants and rate of formation increase in the order 4-NH2Py 4-EtPy > 4-MePy > Py > 2-NH2Py > 2-EtPy. The data have been interpreted based on the basicity of the ligand, -back bonding from Co(III) → L and hard and soft interactions. The rate of substitution of H2O varies with the pKa of the incoming ligand, thus establishing the existence of nucleophilic participation of the ligand in the transition state. We have investigated the DNA binding of bromomethyl(aqua)cobaloxime with DNA. Bromomethyl(ligand)cobaloximes were isolated and characterized by elemental analysis, IR and NMR (1H, 13C) spectra.

  17. Evaluation of model simulated and MODIS-Aqua retrieved sea surface chlorophyll in the eastern Arabian Sea

    Science.gov (United States)

    Chakraborty, Kunal; Gupta, Anubhav; Lotliker, Aneesh A.; Tilstone, Gavin

    2016-11-01

    In this study we assess the accuracy of sea surface Chlorophyll-a (Chla) retrieved from satellite (MODIS-Aqua), using standard OC3M algorithm, and from a Regional Ocean Modelling System (ROMS) biophysical model against in situ data, measured in surface waters of the eastern Arabian Sea, from April 2009 to December 2012. MODIS-Aqua OC3M Chla concentrations showed a high correlation with the in situ data with slope close to unity and low root mean square error. In comparison, the ROMS model underestimated Chla, though the correlation was significant indicating that the model is capable of reproducing the trend in in situ Chla. Time Series trends in Chla were examined against wind driven Upwelling Indices (UIW) from April 2009 to December 2012 in north-eastern (Gujarat) and south-eastern (Kochi) coastal waters of the Arabian Sea. The annual peak in Chla along the Kochi coast during the summer monsoon was adequately captured by the model. It is well known that the peak in surface Chla along the Kochi and Gujarat coasts during the summer monsoon is the result of coastal upwelling, which the ROMS model was able to reproduce accurately. The maximum surface Chla along the Gujarat coast during the winter monsoon is due to convective mixing, which was also significantly captured by ROMS biophysical model. There was a lag of approximately one week between the maximum surface Chla and the peak in the Upwelling Index.

  18. Application of AquaCrop model for maize under water and nitrogen managements in a humid environment

    Directory of Open Access Journals (Sweden)

    Ebrahim Amiri

    2016-08-01

    Full Text Available Globally, it is well debated fact that the water productivity in agriculture needs to be raised in order to meet the increasing demand for the feed and food production, which will double by 2050. Simulation models have been developed for predicting the effects of soil, water and nutrients on growth and water productivity of different crops. In this study, AquaCrop model was calibrated for grain maize (Single Cross 260 using drip irrigation system under varying irrigation and nitrogen levels. The intervals of irrigation were 6 days (F1, 12 days (F2 and 18 days (F3 which combined with different nitrogen levels of 0 (N1, 120 (N2, 180 (N3 and 240 kg ha-1. Root Mean Square Error (RMSE, normalized Root Mean Square Error (RMSEn, Mean Absolute Error (MAE, Prediction error (Pe and coefficient of determination (R2 were used to test the model performance. The model was calibrated for simulating maize grain and biomass yield for all treatment levels with the prediction error 0.37AquaCrop model simulated aboveground biomass and grain yield in normal conditions more accurately than moderate and severe water stress conditions.

  19. The NASA Earth Observing System (EOS) Terra and Aqua Mission Moderate Resolution Imaging Spectroradiometer (MODIS: Science and Applications

    Science.gov (United States)

    Salomnson, Vincent V.

    2003-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) on the Earth Observing System (EOS) Terra Mission began to produce data in February 2000. The EOS Aqua mission was launched successfully May 4,2002 with another MODIS on it and "first light" observations occurred on June 24,2002. The Terra MODIS is in a sun-synchronous orbit going north to south in the daylight portion of the orbit crossing the equator at about 1030 hours local time. The Aqua spacecraft operates in a sun-synchronous orbit going south to north in the daylight portion of the orbit crossing the equator at approximately 1330 hours local time. The spacecraft, instrument, and data systems for both MODIS instruments are performing well and are producing a wide variety of data products useful for scientific and applications studies in relatively consistent fashion extending from November 2000 to the present. Within the approximately 40 MODIS data products, several are new and represent powerful and exciting capabilities such the ability to provide observations over the globe of fire occurrences, microphysical properties of clouds and sun-stimulated fluorescence from phytoplankton in the surface waters of the ocean. The remainder of the MODIS products exceeds or, at a minimum, matches the capabilities of products from heritage sensors such as, for example, the Advanced Very High Resolution Radiometer (AVHRR). Efforts are underway to provide data sets for the greater Earth science community and to improve access to these products at the various Distributed Active Archive Centers (DAAC's) or through Direct Broadcast (DB) stations.

  20. Aerosol optical depth over central north Asia based on MODIS-Aqua data

    Science.gov (United States)

    Avgousta Foutsi, Athina; Korras Carraca, Marios Bruno; Matsoukas, Christos; Biskos, George

    2016-04-01

    Atmospheric aerosols, both natural and anthropogenic, can affect the regional and global climate through their direct, indirect, and semi-direct effects on the radiative energy budget of the Earth-atmosphere system. To quantify these effects it is important to determine the aerosol load, and an effective way to do that is by measuring the aerosol optical depth (AOD). The central Asia region (mainly the Caspian and Aral sea basins), the arid and semi-arid regions of Western China as well as Siberia are of great interest due to the significant natural sources of mineral aerosols originating from local deserts and biomass burning from wildfires in boreal forests. What is of particular interest in the region is the phenomenal shrinking and desertification of the Aral Sea that drives an intense salt and dust transport from the exposed sea-bed to the surrounding regions with important implications in regional air quality. Anthropogenic particles are also observed due to fossil-fuel combustion occurring mainly at oil refineries in the Caspian Sea basin. Here we investigate the spatial and temporal variability of the AOD at 550 nm over central Asia, Siberia and western China, in the region located between 35° N - 65° N and 45° E - 110° E. For our analysis we use Level-3 daily MODIS - Aqua Dark Target - Deep Blue combined product, from the latest collection (006), available in a 1°×1° resolution (ca. 100 km × 100 km) over the period 2002-2014. Our results indicate a significant spatial variability of the aerosol load over the study region. The highest AODs are observed over the Aral Sea year-round, with extreme values reaching 2.1 during July. In the rest of our study region a clear seasonal cycle with highest AOD values (up to 1.2 over the Taklamakan Desert) during spring and summer is observed. The arid parts of central north Asia are characterized by larger aerosol loads during spring, lower but still high AOD in summer and much lower values in autumn and spring

  1. Fractional Snowcover Estimates from Earth Observing System (EOS) Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS)

    Science.gov (United States)

    Salomonson, Vincent V.

    2002-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) on the NASA Earth Observing System (EOS) Terra and Aqua missions has shown considerable capability for mapping snowcover. The typical approach that has used, along with other criteria, the Normalized Snow Difference Index (NDSI) that takes the difference between 500 meter observations at 1.64 micrometers (MODIS band 6) and 0.555 micrometers (MODIS band 4) over the sum of these observations to determine whether MODIS pixels are snowcovered or not in mapping the extent of snowcover. For many hydrological and climate studies using remote sensing of snowcover, it is desirable to assess if the MODIS snowcover observations could not be enhanced by providing the fraction of snowcover in each MODIS observation (pixel). Pursuant to this objective studies have been conducted to assess whether there is sufficient "signal%o in the NDSI parameter to provide useful estimates of fractional snowcover in each MODIS 500 meter pixel. To accomplish this objective high spatial resolution (30 meter) Landsat snowcover observations were used and co-registered with MODIS 500 meter pixels. The NDSI approach was used to assess whether a Landsat pixel was or was not snowcovered. Then the number of snowcovered Landsat pixels within a MODIS pixel was used to determine the fraction of snowcover within each MODIS pixel. The e results were then used to develop statistical relationships between the NDSI value for each 500 meter MODIS pixel and the fraction of snowcover in the MODIS pixel. Such studies were conducted for three widely different areas covered by Landsat scenes in Alaska, Russia, and the Quebec Province in Canada. The statistical relationships indicate that a 10 percent accuracy can be attained. The variability in the statistical relationship for the three areas was found to be remarkably similar (-0.02 for mean error and less than 0.01 for mean absolute error and standard deviation). Independent tests of the relationships were

  2. Surface circulation patterns in the Gulf of California derived from MODIS Aqua 250 m

    Science.gov (United States)

    Martínez-Flores, G.; Salinas-González, F.; Gutiérrez de Velasco-Sanromán, G.; Godínez-Orta, L.

    2009-04-01

    The Gulf of California (GC) is a marginal elongated and semi-enclosed sea located at northwest of Mexico, between the Peninsula of Baja California and the mainland Mexico. The considered area average 150 km in width and 1500 km in length, from the mouth of the Colorado River to Cabo Corrientes, Jalisco. It has a maximum depth of 3600 m at the southern inlet and the northern region average 200 m in deep. The study of superficial circulation patterns in the GC is of interest because its relevance to the mechanisms of transport for distribution of a variety of materials -plankton, contaminants, microalgae, etc.- and its association with areas of sedimentary deposits, zones where there is a higher probability for fishing or related to the presence of certain species of marine life. Recent studies explain the circulation of the GC as a result of the Pacific Ocean's forcing, wind, heat fluxes on the sea surface and the interaction between the flow produced by these agents and bathymetry. The objective of this work was to obtain evidence of the patterns of surface circulation using a spatial resolution of 250 m over a period of two to seven days (depending on cloud cover), which offered images from the MODIS Level 1B. This essay is an attempt to contribute with more information to the understanding of the regional dynamics of the GC and its local influence on the zones bordering the coast. Thus, MODIS Aqua 250 m data was used, to which algorithms were applied in order to enhance the contrast of reflectance levels of these bands (0.620-0.670 and 0.841-0.876 µm) within the marine environment. The results are associated with suspended particulate matter (SPM), which we used as tracers of the surface circulation, using a sequence of images from January 2004 to December 2008. Algorithms for dust and cloud detection were used and incorporated with thermal band images, in which zones of terrigenous contribution by eolian transport were identified. Furthermore, pluvial

  3. Deriving the effect of wind speed on clean maritime aerosol optical properties using the A-Train satellites

    Directory of Open Access Journals (Sweden)

    V. P. Kiliyanpilakkil

    2011-02-01

    Full Text Available Relationship between "clean marine" aerosol optical properties and ocean surface wind speed is explored using remotely sensed data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP on board the CALIPSO satellite and the Advanced Microwave Scanning Radiometer (AMSR-E on board the AQUA satellite. Detailed data analyses are carried out over 15 regions selected to be representative of different areas of the global ocean for the time period from June 2006 to June 2010. Based on remotely sensed optical properties the CALIPSO algorithm is capable of discriminating "clean marine" aerosols from other types often present over the ocean (such as urban/industrial pollution, desert dust and biomass burning. The global mean optical depth of "clean marine" aerosol at 532 nm (AOD532 is found to be 0.052 ± 0.038. The mean layer integrated volume depolarization ratio of marine aerosols is 0.016 ± 0.012, the value representative of sea salt crystals. Integrated attenuated backscatter and color ratio of marine aerosols at 532 nm were obtained to be 0.003 ± 0.002 sr−1 and 0.530 ± 0.149, respectively. A logistic regression between AOD532 and 10-meter surface wind speed (U10 revealed three distinct regions. For surface winds lower than 4 m s−1, the mean CALIPSO-derived AOD532 is found to be 0.02 ± 0.003 with little dependency on the surface wind speed. For surface winds from 4 m s−1 to 12 m s−1, representing the dominant fraction of all available data, marine aerosol optical depth is linearly correlated with the U10, with a slope of 0.0062 s m−1. In this intermediate wind speed region, the AOD532 vs. U10 regression derived here is comparable to previously reported relationships. At very high wind speed values (U10 > 18 m s−1, the AOD532

  4. Determination of heavy metals (Pd, Cd, Cu, Zn, Cr) in sedimentary reference materials with IDMS: Total concentration and aqua regia soluble portion

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, A.; Heumann, K.G.

    1988-12-01

    The total concentration and the aqua regia soluble portion of traces of Pb, Cd, Cu, Zn, and Cr are determined with isotope dilution mass spectrometry (IDMS) in three different types of sediments using a thermal quadrupole instrument (THQ). The results are compared with those obtained by other methods during a certification project to establish these sediments (BCR 277, BCR 280, BCR 320) as standard reference materials. The IDMS (THQ) results are in good agreement with the preliminary certification values and the results of two other laboratories, which applied IDMS using magnetic sector field mass spectrometers. Significant differences between the different analytical methods were found for the total Pb concentration, which could be explained by adsorption and coprecipitation effects during the chemical pretreatment of samples. Using aqua regia instead of HF/HNO/sub 3/ for the decomposition of sediments, only 65%-95% of the total Pb and 60%-90% of the total Cr could be dissolved. On the other hand, only a small or negligible portion of Zn, Cd, and Cu could not be dissolved by aqua regia. The IDMS values for the aqua regia soluble Cr portion are significantly higher compared to the results of other methods. This can be explained by adsorption effects.

  5. Assessment of the AquaCrop model for use in simulation of irrigated winter wheat canopy cover, biomass, and grain yield in the North China Plain.

    Science.gov (United States)

    Jin, Xiu-liang; Feng, Hai-kuan; Zhu, Xin-kai; Li, Zhen-hai; Song, Sen-nan; Song, Xiao-yu; Yang, Gui-Jun; Xu, Xin-gang; Guo, Wen-shan

    2014-01-01

    Improving winter wheat water use efficiency in the North China Plain (NCP), China is essential in light of current irrigation water shortages. In this study, the AquaCrop model was used to calibrate, and validate winter wheat crop performance under various planting dates and irrigation application rates. All experiments were conducted at the Xiaotangshan experimental site in Beijing, China, during seasons of 2008/2009, 2009/2010, 2010/2011 and 2011/2012. This model was first calibrated using data from 2008/2009 and 2009/2010, and subsequently validated using data from 2010/2011 and 2011/2012. The results showed that the simulated canopy cover (CC), biomass yield (BY) and grain yield (GY) were consistent with the measured CC, BY and GY, with corresponding coefficients of determination (R(2)) of 0.93, 0.91 and 0.93, respectively. In addition, relationships between BY, GY and transpiration (T), (R(2) = 0.57 and 0.71, respectively) was observed. These results suggest that frequent irrigation with a small amount of water significantly improved BY and GY. Collectively, these results indicate that the AquaCrop model can be used in the evaluation of various winter wheat irrigation strategies. The AquaCrop model predicted winter wheat CC, BY and GY with acceptable accuracy. Therefore, we concluded that AquaCrop is a useful decision-making tool for use in efforts to optimize wheat winter planting dates, and irrigation strategies.

  6. Influences on the Use of the "Fishing: Get in the Habitat! MinnAqua Leader's Guide" and Implications for Curriculum Dissemination

    Science.gov (United States)

    Athman Ernst, Julie

    2010-01-01

    The "Fishing: Get in the Habitat! MinnAqua Leader's Guide" is a curriculum created by the Minnesota Department of Natural Resources for educators working primarily with children in grades three through five in formal and nonformal education settings. Like many agency-developed supplemental educational resources, the Leader's Guide is available…

  7. De novo quence analysis and intact mass measurements for characterization of phycocyanin subunit isoforms from the blue-green alga Aphanizomenon flos-aquae

    DEFF Research Database (Denmark)

    Rinalducci, Sara; Roepstorff, Peter; Zolla, Lello

    2009-01-01

    In this work, partial characterization of the primary structure of phycocyanin from the cyanobacterium Aphanizomenon flos-aquae (AFA) was achieved by mass spectrometry de novo sequencing with the aid of chemical derivatization. Combining N-terminal sulfonation of tryptic peptides by 4-sulfophenyl...

  8. Assessment of the AquaCrop model for use in simulation of irrigated winter wheat canopy cover, biomass, and grain yield in the North China Plain.

    Directory of Open Access Journals (Sweden)

    Xiu-liang Jin

    Full Text Available Improving winter wheat water use efficiency in the North China Plain (NCP, China is essential in light of current irrigation water shortages. In this study, the AquaCrop model was used to calibrate, and validate winter wheat crop performance under various planting dates and irrigation application rates. All experiments were conducted at the Xiaotangshan experimental site in Beijing, China, during seasons of 2008/2009, 2009/2010, 2010/2011 and 2011/2012. This model was first calibrated using data from 2008/2009 and 2009/2010, and subsequently validated using data from 2010/2011 and 2011/2012. The results showed that the simulated canopy cover (CC, biomass yield (BY and grain yield (GY were consistent with the measured CC, BY and GY, with corresponding coefficients of determination (R(2 of 0.93, 0.91 and 0.93, respectively. In addition, relationships between BY, GY and transpiration (T, (R(2 = 0.57 and 0.71, respectively was observed. These results suggest that frequent irrigation with a small amount of water significantly improved BY and GY. Collectively, these results indicate that the AquaCrop model can be used in the evaluation of various winter wheat irrigation strategies. The AquaCrop model predicted winter wheat CC, BY and GY with acceptable accuracy. Therefore, we concluded that AquaCrop is a useful decision-making tool for use in efforts to optimize wheat winter planting dates, and irrigation strategies.

  9. Mobility, turnover and storage of pollutants in soils, sediments and waters: Achievements and results of the EU project AquaTerra. A review

    NARCIS (Netherlands)

    Barth, J.A.C.; Grathwohl, P.; Fowler, H.J.; Bellin, A.; Gerzabek, M.H.; Lair, G.J.; Barceló, D.; Petrovic, M.; Navarro, A.; Négrel, P.; Petelet-Giraud, E.; Darmendrail, D.; Rijnaarts, H.; Langenhoff, A.; Weert, J. de; Slob, A.; Zaan, B.M. van der; Gerritse, J.; Frank, E.; Gutierrez, A.; Kretzschmar, R.; Gocht, T.; Steidle, D.; Garrido, F.; Jones, K.C.; Meijer, S.; Moeckel, C.; Marsman, A.; Klaver, G.; Vogel, T.; Bürger, C.; Kolditz, O.; Broers, H.P.; Baran, N.; Joziasse, J.; Tümpling, W. von; Gaans, P. van; Merly, C.; Chapman, A.; Brouyère, S.; Batlle Aguilar, J.; Orban, Ph.; Tas, N.; Smidt, H.

    2009-01-01

    AquaTerra is one of the first environmental projects within the 6th Framework program by the European Commission. It began in June 2004 with a multidisciplinary team of 45 partner organizations from 13 EU countries, Switzerland, Serbia, Romania and Montenegro. Results from sampling and modeling in 4

  10. Crystal structure of poly[[di-μ2-aqua-aqua­sodium] 4-amino-3,5,6-tri­chloro­pyridine-2-carboxyl­ate trihydrate], the sodium salt of the herbicide picloram

    OpenAIRE

    Smith, Graham

    2015-01-01

    In the structure of the title complex, {[Na(H2O)3](C6H2Cl3N2O2)·3H2O} n , the sodium salt of the herbicide picloram, the cation adopts a polymeric chain structure, based on μ2-aqua-bridged NaO5 trigonal–bipyramidal complex units which have, in addition, a singly bonded water mol­ecule. Each of the bridges within the chain, which extends parallel to the a axis, is centrosymmetric, with Na⋯Na separations of 3.4807 (16) and 3.5109 (16) Å. In the crystal, there are three water mol­ecules of solva...

  11. Assessment of two aerosol optical thickness retrieval algorithms applied to MODIS Aqua and Terra measurements in Europe

    Directory of Open Access Journals (Sweden)

    P. Glantz

    2012-07-01

    Full Text Available The aim of the present study is to validate AOT (aerosol optical thickness and Ångström exponent (α, obtained from MODIS (MODerate resolution Imaging Spectroradiometer Aqua and Terra calibrated level 1 data (1 km horizontal resolution at ground with the SAER (Satellite AErosol Retrieval algorithm and with MODIS Collection 5 (c005 standard product retrievals (10 km horizontal resolution, against AERONET (AErosol RObotic NETwork sun photometer observations over land surfaces in Europe. An inter-comparison of AOT at 0.469 nm obtained with the two algorithms has also been performed. The time periods investigated were chosen to enable a validation of the findings of the two algorithms for a maximal possible variation in sun elevation. The satellite retrievals were also performed with a significant variation in the satellite-viewing geometry, since Aqua and Terra passed the investigation area twice a day for several of the cases analyzed. The validation with AERONET shows that the AOT at 0.469 and 0.555 nm obtained with MODIS c005 is within the expected uncertainty of one standard deviation of the MODIS c005 retrievals (ΔAOT = ± 0.05 ± 0.15 · AOT. The AOT at 0.443 nm retrieved with SAER, but with a much finer spatial resolution, also agreed reasonably well with AERONET measurements. The majority of the SAER AOT values are within the MODIS c005 expected uncertainty range, although somewhat larger average absolute deviation occurs compared to the results obtained with the MODIS c005 algorithm. The discrepancy between AOT from SAER and AERONET is, however, substantially larger for the wavelength 488 nm. This means that the values are, to a larger extent, outside of the expected MODIS uncertainty range. In addition, both satellite retrieval algorithms are unable to estimate α accurately, although the MODIS c005 algorithm performs better. Based on the inter-comparison of the SAER and MODIS c005 algorithms, it was found that SAER on the whole is

  12. 冬小麦生物量和产量的AquaCrop模型预测%Yield and Biomass Prediction Testing of AquaCrop Model for Winter Wheat

    Institute of Scientific and Technical Information of China (English)

    杜文勇; 何雄奎; Shamaila Z; 胡振方; 曾爱军; Muller J

    2011-01-01

    Using the winter wheat in North China as research object, AquaCrop model was applied in different technology of irrigation, included drip irrigation, sprinkler irrigation and furrow irrigation. The main parameters like soil and crop characteristics and so on, were adjusted. In addition, the effective simulation method for crop yield and biomass was researched. The study showed that some simulated values like yield and biomass of soil were significative. The relative error (RE) was low. Simulated data was a little higher than the observed one. All of the modeling efficiency ( EF) was more than 0. 95. The modeling was better for yield than that for biomass. The modeling was also the most efficient for drip irrigation in the three kind of irrigation technology.%以华北地区冬小麦为研究对象,将AquaCrop作物生长模型应用到滴灌、喷灌、漫灌中,对模型主要参数如气象、土壤、作物特性等进行调整,并对作物产量和生物量模拟的有效方法进行了研究.模拟结果表明,产量和收获时地上部分生物量的模拟值与实测值较为接近且略高于实测值,模型性能指数均高于0.95.产量模拟效果优于生物量,滴灌模拟效果最好.

  13. Fecundity studies of the African catifshClarias gariepinus (Burchell, 1822) fed Coppens feed and Unical aqua feed in circular concrete tanks

    Institute of Scientific and Technical Information of China (English)

    Victor Oscar Eyo; Albert Philip Ekanem; Vincent Ajom Ajom

    2016-01-01

    Objective:To determine and compare the fecundity ofClarias gariepinus (C. gariepinus) fed with Unical aqua feed and Coppens feeds in concrete tanks, including the nature of relationship that exist between fecundity and morphometric indices of fish such as total length and total weight. Methods:An experiment was conducted for 6 months in the fish farm of University of Calabar with two triplicate groups of 50C. gariepinus post-fingerlings. The experimental fish weighing (0.50 ± 0.02) kg were stocked in concrete tanks (circular) of 16.63 m2area. The tanks were labelled A1, A2, A3, B1, B2 and B3. Fish in tank A1, A2 and A3 were fed with Coppens feed and fish in tanks B1, B2 and B3 were fed with Unical aqua feed. Feeding was done twice daily (9:00 and 16:00) at 3% of their body weight. Results: Mean fecundity ofC. gariepinus fed with Unical aqua feed (68 366.67 ± 15 966. 29) eggs varied significantly (P 0.05) thanC. gariepinus fed with Unical aqua feed (50.37% ± 1.29 %). Water quality parameters including ammonia (mg/L), pH, water temperature (°C) and dissolved oxygen (mg/L) fell within the recommended range for the culture of fresh water fish. Conclusions: Fecundity ofC. gariepinus reared in concrete tank was significantly influenced by the experimental feed. Therefore, on the bases of affordability and availability to farmers, Unical aqua feed is more economical and is recommended as a cost-effective cultivation of femaleC. gariepinus broodstock.

  14. Displacement of aqua ligands from the hydroxopentaaquarhodium(III) ion by 1-hydroxybenzotriazole (HOBt): A kinetic and mechanistic approach

    Indian Academy of Sciences (India)

    Biplab K Bera; Arup Mandal; Biswarup Maity; Sumon Ray; Parnajyoti Karmakar; Subala Mondal; Subhasis Mallick; Alak K Ghosh

    2012-07-01

    The kinetics of the reaction of HOBt with [Rh(H2O)5(OH)]2+ has been studied spectrophotometrically in aqueous medium as a function of [Rh(H2O)5OH2+], [HOBt], pH and temperature. At pH 4.3, the reaction proceeds via a rapid outer sphere association complex formation step followed by two consecutive steps. The first of these involves ligand-assisted anation, while the second involves chelation as the second aqua ligand is displaced. The association equilibrium constant for the outer sphere complex formation has been evaluated together with the rate constants for the two subsequent steps. The activation parameters for both steps have been evaluated using Eyrings equation. Thermodynamic parameters calculated from the temperature dependence of the outer sphere association equilibrium constants are also consistent with an associative mode of activation. The product of the reaction has been characterized by IR and ESI-mass spectroscopic analysis.

  15. The Improvement Two Cases Coughing and Sputum sign Sequela of Pneumonia by Homins Placenta Aqua-Acupuncture

    Directory of Open Access Journals (Sweden)

    Kim, Eun-Gon

    2003-12-01

    Full Text Available Coughing and sputum are symptoms of sequela of Pneumonia. Oriental medicine call it Hae su. Hae su is common sign of lung disease. Hominis Placenta is the dried placenta of a healthy women. The nature of Hominis Placenta is warm and its taste sweet-salty. It has correspondence to the meridians of lung and kindey. Hominis Placenta acupuncture therapy has effect on invigoration of vital energy nourishing blood and tonifying the essence. It can be applied to the disease as Asthma, pulmonary tuberculosis, chronic hepatitis, liver cirrhosis, degenerative change and cerebrovascular disease. We treated two cases coughing and sputum sign Sequela of Pneumonia by Hominis Placenta Aqua-Acupuncture. The symptoms was improved and the patients satisfied

  16. Aqua-eroticum: an unusual autoerotic fatality in a lake involving a home-made diving apparatus.

    Science.gov (United States)

    Sauvageau, Anny; Racette, Stéphanie

    2006-01-01

    The term Aqua-eroticum was first introduced in 1984 by Sivaloganathan to describe the unusual autoerotic death of a man using submersion as an asphyxia method. This was the first case of that kind, and since then, no other case of autoerotic submersion has been reported, nor other autoerotic fatality in open water. Here we report the case of a 25-year-old man, nude under a home-made plastic body suit, overdressed for the season with winter clothes and restrained by complex bondage. He was submersed, tied underwater to a boat and was using a home-made diving apparatus for air supply. Death was ruled as accidental autoerotic asphyxia from rebreathing, caused by the faulty air-supply device. PMID:16423240

  17. DINUCLEAR NICKEL(II PIVALATE WITH µ-AQUA AND DI-µ-PIVALATO BRIDGES SHOWING A FERROMAGNETIC INTERACTION

    Directory of Open Access Journals (Sweden)

    Masahiro Mikuriya

    2014-12-01

    Full Text Available Dinuclear nickel(II complex, [Ni2{O2CC(CH33}4(OH2{HO2CC(CH33}4] (1, was synthesized and characterized by elemental analysis, IR and UV-Vis-NIR spectroscopy, and temperature dependence of magnetic susceptibilities (4.5—300 K. Single-crystal X-ray crystallography revealed a dinuclear core with µ-aqua and di-µ-pivalato bridges having monodentate pivalato and monodentate pivalic acid molecules. Magnetic data analysis showed a ferromagnetic interactions between the two nickel atoms with g = 2.251, J = 2.78 cm−1, D = 3.75 cm–1, and tip = 184 x 10–6 cm3 mol–1; g = 2.253, J = 2.73 cm−1, D = –3.26 cm–1, and tip = 176 x 10–6 cm3 mol–1.

  18. Characterization of turbidity in Florida's Lake Okeechobee and Caloosahatchee and St. Lucie estuaries using MODIS-Aqua measurements.

    Science.gov (United States)

    Wang, Menghua; Nim, Carl J; Son, Seunghyun; Shi, Wei

    2012-10-15

    This paper describes the use of ocean color remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to characterize turbidity in Lake Okeechobee and its primary drainage basins, the Caloosahatchee and St. Lucie estuaries from 2002 to 2010. Drainage modification and agricultural development in southern Florida transport sediments and nutrients from watershed agricultural areas to Lake Okeechobee. As a result of development around Lake Okeechobee and the estuaries that are connected to Lake Okeechobee, estuarine conditions have also been adversely impacted, resulting in salinity and nutrient fluctuations. The measurement of water turbidity in lacustrine and estuarine ecosystems allows researchers to understand important factors such as light limitation and the potential release of nutrients from re-suspended sediments. Based on a strong correlation between water turbidity and normalized water-leaving radiance at the near-infrared (NIR) band (nL(w)(869)), a new satellite water turbidity algorithm has been developed for Lake Okeechobee. This study has shown important applications with satellite-measured nL(w)(869) data for water quality monitoring and measurements for turbid inland lakes. MODIS-Aqua-measured water property data are derived using the shortwave infrared (SWIR)-based atmospheric correction algorithm in order to remotely obtain synoptic turbidity data in Lake Okeechobee and normalized water-leaving radiance using the red band (nL(w)(645)) in the Caloosahatchee and St. Lucie estuaries. We found varied, but distinct seasonal, spatial, and event driven turbidity trends in Lake Okeechobee and the Caloosahatchee and St. Lucie estuary regions. Wind waves and hurricanes have the largest influence on turbidity trends in Lake Okeechobee, while tides, currents, wind waves, and hurricanes influence the Caloosahatchee and St. Lucie estuarine areas.

  19. Calibration and Validation of Aqua AIRS and AMSU Measurements using COSMIC Global Positioning System Radio Occultation Observations

    Science.gov (United States)

    Ho, S. P.; Peng, L.

    2015-12-01

    On board NASA Aqua satellite, the hyper-spectral infrared sounding from Atmospheric Infrared Sounder (AIRS) is the first of a new generation of operational remote sensors for upwelling atmospheric emission that provide excellent temperature and water vapor retrievals at middle atmosphere, which has significant impacts on short-term numerical weather forecasts. Also on board NASA Aqua satellite, Advanced Microwave Sounding Unit (AMSU) measurements provide the all weather temperature and water vapor profiles which are used as the first guess for AIRS inversion algorithm. However, due to lack of absolute on orbit calibration, both AIRS and AMSU also exhibit biases in retrieving atmospheric temperatures and moistures when compared with in situ measurements. These retrieval biases have diverse and complex dependencies on the temperature/moisture being measured, the season and geographical location, surface conditions, and sensor temperature, which is difficult to quantify. The purpose of this study is to demonstrate the usefulness of Global Positioning System (GPS) Radio Occultation (RO) data to serve as a climate calibration observatory in orbit to calibrate and validate AIRS and AMSU measurements. In this study, we use COSMIC RO data to simulate AMSU and AIRS brightness temperatures for the lower stratosphere (TLS) and compare them to AMSU TLS and those of AIRS brightness temperatures at the same height. Our analysis shows that because RO data do not contain mission-dependent biases and orbit drift errors, and are not affected by on-orbit heating and cooling of the satellite component, they are very useful to identify the AMSU time/location dependent biases for different NOAA missions and possible long term drift of the AIRS retrieved temperatures.

  20. Pregnant women maintain body temperatures within safe limits during moderate-intensity aqua-aerobic classes conducted in pools heated up to 33 degrees Celsius: an observational study

    Directory of Open Access Journals (Sweden)

    Amanda L Brearley

    2015-10-01

    Full Text Available Question: What is the body temperature response of healthy pregnant women exercising at moderate intensity in an aqua-aerobics class where the water temperature is in the range of 28 to 33 degrees Celsius, as typically found in community swimming pools? Design: An observational study. Participants: One hundred and nine women in the second and third trimester of pregnancy who were enrolled in a standardised aqua-aerobics class. Outcome measures: Tympanic temperature was measured at rest pre-immersion (T1, after 35 minutes of moderate-intensity aqua-aerobic exercise (T2, after a further 10 minutes of light exercise while still in the water (T3 and finally on departure from the facility (T4. The range of water temperatures in seven indoor community pools was 28.8 to 33.4 degrees Celsius. Results: Body temperature increased by a mean of 0.16 degrees Celsius (SD 0.35, p < 0.001 at T2, was maintained at this level at T3 and had returned to pre-immersion resting values at T4. Regression analysis demonstrated that the temperature response was not related to the water temperature (T2 r = –0.01, p = 0.9; T3 r = –0.02, p = 0.9; T4 r = 0.03, p = 0.8. Analysis of variance demonstrated no difference in body temperature response between participants when grouped in the cooler, medium and warmer water temperatures (T2 F = 0.94, p = 0.40; T3 F = 0.93, p = 0.40; T4 F = 0.70, p = 0.50. Conclusions: Healthy pregnant women maintain body temperatures within safe limits during moderate-intensity aqua-aerobic exercise conducted in pools heated up to 33 degrees Celsius. The study provides evidence to inform guidelines for safe water temperatures for aqua-aerobic exercise during pregnancy. [Brearley AL, Sherburn M, Galea MP, Clarke SJ, (2015 Pregnant women maintain body temperatures within safe limits during moderate-intensity aqua-aerobic classes conducted in pools heated up to 33 degrees Celsius: an observational study. Journal of

  1. Soil moisture estimation over an arid environment in Mongolia from passive microwave remote sensing based on a simplified parameterization method%基于简化参数方法的蒙古干旱区土壤湿度被动微波遥感

    Institute of Scientific and Technical Information of China (English)

    田辉; 王澄海; 文军; 王欣; 陆登荣; 吕少宁

    2012-01-01

    Satellite passive microwave remote sensing provides a major basis for the analysis of temporal and spatial variation of top soil moisture at large scales. A global soil moisture data product is currently released by the National Aeronautics and Space Administration (NASA) of USA based on AMSR-E (the Advanced Microwave Scanning Radiometer for the Earth Observing System onboard the NASA EOS Aqua satellite) global dual-polarization brightness temperatureobservations of the Earth. But the accuracy of this soil moisture product is not satisfactory in arid Mongolian regions. Based on a simplified parameterization method for characterizing the effects of the sparse vegetation cover and surface roughness on surface microwave emission, the estimation of daytime (local noon) and nighttime (local midnight) top soil moisture during a near two-year period from October 1, 2005 to September 20, 2007 over the arid CEOP(The Coordinated Energy and Water Cycle Observations Project)-Mongolia experiment area was conducted based on a multifrequency algorithm by mainly using AMSR-E 6. 9 GHz, 10. 7 GHz and 18. 7 GHz vertical-polarized brightness temperature data. In the inversion model, the only model parameter asking for experimental calibration, I. E. , the vegetation single scattering albedo, could be achieved through optimization technique by using in-situ soil moisture measurements. The results showed that the root mean square error (RMSE) between satellite estimated soil moisture and ground-measured soil moisture was close to 0. 030 cm3/cm3. Without other supplementary data else, the retrieval algorithm proposed in this paper may be applied to near real-time monitoring of the dynamic variation in top soil moisture at large scales, in an all-weather working manner, over arid and or semiarid environments characterized by natural sparse vegetation conditions. Therefore, it will be promising to provide sustaining and reliable initial near-surface soil moisture information for the long

  2. Application of AquaCrop Model for Simulting the Summer Maize Water Use in North China Plain%AquaCrop 模型在华北平原夏玉米水分研究中的应用

    Institute of Scientific and Technical Information of China (English)

    刘兴冉; 沈彦俊

    2014-01-01

    为将 AquaCrop 模型应用于华北平原夏玉米水分研究中,于2011-2012年在中国科学院栾城农业生态系统试验站进行了夏玉米水分处理试验,在参数率定与模型验证的基础上对华北平原水量平衡及水分利用效率的现状进行了分析。结果表明, AquaCrop 模型能够较好地模拟夏玉米的产量、生物量、冠层发育过程以及表层土壤水储量的动态变化。从生物量角度来看,夏玉米的水分利用效率在8月中旬达到最大,可达10 kg/m3左右,其整个生长季水分利用效率为4.9-5.8 kg/m3;从产量角度来看,水分利用效率为2.3-3.0 kg/m3,且在整个生长季土壤水储量呈增加趋势。研究阐明了 AquaCrop 模型在华北平原地区有较好的适用性,可以应用于夏玉米耗水与水分利用效率方面的研究。%To evaluate the applicability ofthe A quaC rop m odelforthe w aterconsum ption ofsum m erm aize in the N orth C hina Plain (NCP),a field experim entw asconducted in 2011-2012 in Luancheng A griculturalEcosystem Experim ental Station of the C hinese A cadem y of Sciences.A fter the param eter calibration and the m odelvalidation,the m odelw as then applied to analyze the w ater balance and w ater use efficiency of the sum m er m aize cropping system in NCP.O ur sim ulation results show thatthe A quaC rop m odelw as capable ofsim ulating the yield,biom ass,canopy developm entand surface soilw atercontentofsuch a cropping system .The biom ass-scaled w ateruse efficiency w as estim ated as 4.9-5.8 kg/m 3 during the grow ing season, and reached a peak of 10 kg/m 3 in m id-A ugust, w hile the yield-scaled w ater use efficiency ranged from 2.3 to 3.0 kg/m 3. B esides, the soil w ater content increased during the w hole grow ing season. O verall,the A quaC rop m odelperform ed w ellto sim ulate the developm entofa sum m erm aize cropping system ,and can be applied to evaluate the w aterconsum ption and w ateruse efficiency in

  3. Satellite microwave remote sensing of North Eurasian inundation dynamics: development of coarse-resolution products and comparison with high-resolution synthetic aperture radar data

    International Nuclear Information System (INIS)

    Wetlands are not only primary producers of atmospheric greenhouse gases but also possess unique features that are favourable for application of satellite microwave remote sensing to monitoring their status and trend. In this study we apply combined passive and active microwave remote sensing data sets from the NASA sensors AMSR-E and QuikSCAT to map surface water dynamics over Northern Eurasia. We demonstrate our method on the evolution of large wetland complexes for two consecutive years from January 2006 to December 2007. We apply river discharge measurements from the Ob River along with land surface runoff simulations derived from the Pan-Arctic Water Balance Model during and after snowmelt in 2006 and 2007 to interpret the abundance of widespread flooding along the River Ob in early summer of 2007 observed in the remote sensing products. The coarse-resolution, 25 km, surface water product is compared to a high-resolution, 30 m, inundation map derived from ALOS PALSAR (Advanced Land Observation Satellite phased array L-band synthetic aperture radar) imagery acquired for 11 July 2006, and extending along a transect in the central Western Siberian Plain. We found that the surface water fraction derived from the combined AMSR-E/QuikSCAT data sets closely tracks the inundation mapped using higher-resolution ALOS PALSAR data.

  4. 利用AquaCrop模型模拟旱作覆膜春玉米耗水和产量%Simulating Water Use and Yield of Film Mulched Maize with AquaCrop Model

    Institute of Scientific and Technical Information of China (English)

    刘琦; 龚道枝; 郝卫平; 王罕博; 高翔; 梅旭荣

    2015-01-01

    为检验AquaCrop模型在晋中地区作物生产力模拟效果,于2011-2013年在农业部寿阳旱作农业与环境野外科学观测试验站进行了覆膜和露地春玉米种植对比试验.首先,利用2013年大田数据对模型进行参数校正和率定,使产量、地上生物量模拟值与实测值的相对误差均在5%以内;然后,利用2011 2012年大田数据验证模型;最后,对模型参数进行敏感性分析.结果表明,AquaCrop模型能较好地模拟0~120 cm土壤含水率、农田蒸散和冠层覆盖度(CC)的动态变化,其模拟值和实测值间相关的决定系数(R2)分别高于0.86、0.86和0.96,均方根误差值(RMSE)分别小于0.92%、0.88 mm/d和9.78%,模型性能指数(EF)分别在0.51~0.86、0.43~0.76和0.92~0.99之间.不同处理的最终生物量和经济产量模拟值与实测值的相对误差分别为2.83%~4.42%和3.13%~9.58%.模型敏感分析显示,达到最大冠层覆盖度CCx时间、冠层衰老时间、开花日期、凋萎系数、田间持水率和土壤初始含水率为敏感参数,相对敏感度在0.13~0.58之间变化.该模型能较好地模拟寿阳地区旱作覆膜春玉米的耗水、生长和产量形成过程.

  5. GestAqua.AdaPT - Mediterranean river basin modeling and reservoir operation strategies for climate change adaptation

    Science.gov (United States)

    Alexandre Diogo, Paulo; Nunes, João Pedro; Marco, Machado; Aal, Carlo; Carmona Rodrigues, António; Beça, Pedro; Casanova Lino, Rafael; Rocha, João; Carvalho Santos, Cláudia

    2016-04-01

    Climate change (CC) scenarios for the Mediterranean region include an increase in the frequency and intensity of extreme weather events such as drought periods. higher average temperatures and evapotranspiration, combined with the decrease of annual precipitation may strongly affect the sustainability of water resources. In face of these risks, improving water management actions? by anticipating necessary operational measures is required to insure water quantity and quality according to the needs of the populations and irrigation in agriculture. This is clearly the case of the Alentejo region, southern Portugal, where present climatic conditions already pose significant challenges to water resources stakeholders, mainly from the agricultural and the urban supply sectors. With this in mind, the GestAqua.AdaPT project is underway during 2015 and 2016, aiming at analyzing CC impacts until 2100 and develop operational procedures to ensure water needs are adequately satisfied in the Monte Novo and Vigia reservoirs, which supply water for the city of Évora and nearby irrigation systems. Specific project objectives include: a) defining management and operational adaptation strategies aiming to ensure resource sustainability, both quantitatively and qualitatively; b) evaluate future potential costs and available alternatives to the regional water transfer infrastructure linked with the large Alqueva reservoir implemented in 2011; c) defining CC adaptation strategies to reduce irrigation water needs and d) identification of CC adaptation strategies which can be suitable also to other similar water supply systems. The methodology is centered on the implementation of a cascade of modeling tools, allowing the integrated simulation of the multiple variables under analysis. The project is based on CC scenarios resulting from the CORDEX project for 10 combinations of Global and regional climate models (GCMs and RCMs). The study follows by using two of these combinations

  6. 东北春小麦区AquaCrop模型模拟验证及春小麦生产力初步估测%The Simulation for Northeast Spring Wheat Productivity Based on the AquaCrop Model and Modeling Verification

    Institute of Scientific and Technical Information of China (English)

    李晶; 付驰; 李双双; 张铁楠; 顾万荣; 乔天长; 许为政; 芦玉双; 魏湜

    2014-01-01

    基于实测资料验证AquaCrop作物模型,并应用AquaCrop作物模型初步估测气候变化下春小麦生产力.结果表明,地上生物量模拟值与实测值之间决定系数R2在0.957~0.997之间,地上生物量模拟效果良好;灌浆初期,籽粒产量模拟值与实测值吻合度较高.AquaCrop模型对水分的敏感度大于对温度的敏感度;春小麦的生产力随着大气CO2质量浓度的增加而增长.在东北春小麦区用AquaCrop模型模拟与预估春小麦生产力是可行的.

  7. The design and optimisation of a bubble pump for an aqua-ammonia diffusion absorption heat pump / Stefan van der Walt.

    OpenAIRE

    Van Der Walt, Stefan

    2012-01-01

    Energy shortages around the world necessitated research into alternative energy sources especially for domestic applications to reduce the load on conventional energy sources. This resulted in research done on the possibility of integrating solar energy with an aqua-ammonia diffusion absorption cycle specifically for domestic applications. The bubble pump can be seen as the heart of the diffusion absorption cycle, since it is responsible, in the absence of a mechanical pump, to circulate ...

  8. The AquaDEB project (phase I): Analysing the physiological flexibility of aquatic species and connecting physiological diversity to ecological and evolutionary processes by using Dynamic Energy Budgets

    Science.gov (United States)

    Alunno-Bruscia, Marianne; van der Veer, Henk W.; Kooijman, Sebastiaan A. L. M.

    2009-08-01

    The European Research Project AquaDEB (2007-2011, http://www.ifremer.fr/aquadeb/) is joining skills and expertise of some French and Dutch research institutes and universities to analyse the physiological flexibility of aquatic organisms and to link it to ecological and evolutionary processes within a common theoretical framework for quantitative bioenergetics [Kooijman, S.A.L.M., 2000. Dynamic energy and mass budgets in biological systems. Cambridge University Press, Cambridge]. The main scientific objectives in AquaDEB are i) to study and compare the sensitivity of aquatic species (mainly molluscs and fish) to environmental variability of natural or human origin, and ii) to evaluate the related consequences at different biological levels (individual, population, ecosystem) and temporal scales (life cycle, population dynamics, evolution). At mid-term life, the AquaDEB collaboration has already yielded interesting results by quantifying bio-energetic processes of various aquatic species (e.g. molluscs, fish, crustaceans, algae) with a single mathematical framework. It has also allowed to federate scientists with different backgrounds, e.g. mathematics, microbiology, ecology, chemistry, and working in different fields, e.g. aquaculture, fisheries, ecology, agronomy, ecotoxicology, climate change. For the two coming years, the focus of the AquaDEB collaboration will be in priority: (i) to compare energetic and physiological strategies among species through the DEB parameter values and to identify the factors responsible for any differences in bioenergetics and physiology; and to compare dynamic (DEB) versus static (SEB) energy models to study the physiological performance of aquatic species; (ii) to consider different scenarios of environmental disruption (excess of nutrients, diffuse or massive pollution, exploitation by man, climate change) to forecast effects on growth, reproduction and survival of key species; (iii) to scale up the models for a few species from

  9. The AquaDEB project (phase I): Analysing the physiological flexibility of aquatic species and connecting physiological diversity to ecological and evolutionary processes by using Dynamic Energy Budgets

    OpenAIRE

    ALUNNO-BRUSCIA, Marianne; van der Veer, Henk W.; Kooijman, Sebastiaan A. L. M.

    2009-01-01

    The European Research Project AquaDEB (2007–2011, http://www.ifremer.fr/aquadeb/) is joining skills and expertise of some French and Dutch research institutes and universities to analyse the physiological flexibility of aquatic organisms and to link it to ecological and evolutionary processes within a common theoretical framework for quantitative bioenergetics [Kooijman, S.A.L.M., 2000. Dynamic energy and mass budgets in biological systems. Cambridge University Press, Cambridge]. The main sci...

  10. Data Assimilation of the High-Resolution Sea Surface Temperature Obtained from the Aqua-Terra Satellites (MODIS-SST) Using an Ensemble Kalman Filter

    OpenAIRE

    Takuji Waseda; Varlamov, Sergey M.; Xinyu Guo; Hiroshi Murakami; Toru Miyama; Sourav Sil; Yasumasa Miyazawa

    2013-01-01

    We develop an assimilation method of high horizontal resolution sea surface temperature data, provided from the Moderate Resolution Imaging Spectroradiometer (MODIS-SST) sensors boarded on the Aqua and Terra satellites operated by National Aeronautics and Space Administration (NASA), focusing on the reproducibility of the Kuroshio front variations south of Japan in February 2010. Major concerns associated with the development are (1) negative temperature bias due to the cloud effects, and (2)...

  11. Drought Monitoring and Category of Vegetation Temperature Condition Index Using Aqua-MODIS Data%基于Aqua-MODIS数据的条件植被温度指数干旱等级监测研究

    Institute of Scientific and Technical Information of China (English)

    林巧; 王鹏新; 张树誉; 刘峻明; 李俐

    2014-01-01

    以陕西关中平原为研究区域,选取2003年~2012年每年3月~5月的Aqua-MODIS数据,计算MODIS-VTCI干旱监测结果,通过气象数据对结果进行验证,对比MODIS和AVHRR数据多年同一旬的VTCI干旱监测及等级划分结果,发现两种监测结果反映出的旱情分布规律相同.MODIS-VTCI干旱监测结果表明,2003年、2004年、2005年和2009年关中地区春旱严重,其中3月中旬至4月下旬旱情发生频率较高.2009年MODIS-VTCI干旱等级监测结果表明,关中地区2009年3月中旬、4月上旬和中旬干旱程度严重,且关中东部地区旱情比西部严重.

  12. Synthesis, FT–IR characterization and crystal structure of aqua(5,10,15,20-tetraphenylporphyrinato-κ4Nmanganese(III trifluoromethanesulfonate

    Directory of Open Access Journals (Sweden)

    Wafa Harhouri

    2016-05-01

    Full Text Available In the title salt, [Mn(C44H28N4(H2O](CF3SO3 or [MnIII(TPP(H2O](CF3SO3 (where TPP is the dianion of 5,10,15,20-tetraphenylporphyrin, the MnIII cation is chelated by the four pyrrole N atoms of the porphyrinate anion and additionally coordinated by an aqua ligand in an apical site, completing the distorted square-pyramidal coordination environment. The average Mn—N(pyrrole bond length is 1.998 (9 Å and the Mn—O(aqua bond length is 2.1057 (15 Å. The central MnIII ion is displaced by 0.1575 (5 Å from the N4C20 mean plane of the porphyrinate anion towards the apical aqua ligand. The porphyrinate macrocycle exhibits a moderate ruffling and strong saddle deformations. In the crystal lattice, the [MnIII(TPP(H2O]+ cation and the trifluoromethanesulfonate counter-ions are arranged in alternating planes packed along [001]. The components are linked together through O—H...O hydrogen bonds and much weaker C—H...O and C—H...F interactions. The crystal packing is further stabilized by weak C—H...π interactions involving the pyrrole and phenyl rings of the porphyrin moieties.

  13. Microwave assisted aqua regia extraction of thallium from sediment and coal fly ash samples and interference free determination by continuum source ETAAS after cloud point extraction.

    Science.gov (United States)

    Meeravali, Noorbasha N; Madhavi, K; Kumar, Sunil Jai

    2013-01-30

    A simple cloud point extraction method is described for the separation and pre-concentration of thallium from the microwave assisted aqua regia extracts of sediment and coal fly ash samples. The method is based on the formation of extractable species of thallium and its interaction with hydrophobic solubilizing sites of Triton X-114 micelles in the presence of aqua regia and electrolyte NaCl. These interactions of micelles are used for extraction of thallium from a bulk aqueous phase into a small micelles-rich phase. The potential chloride interferences are eliminated effectively, which enabled interference free determination of thallium from aqua regia extracts using continuum source ETAAS. The parameters affecting the extraction process are optimized. Under the optimized conditions, pre-concentration factor and limit of detection are 40 and 0.2 ng g(-1), respectively. The recoveries are in the range of 95-102%. A characteristic mass, 13 pg was obtained. The accuracy of the method is verified by analyzing certified reference materials such as NIST 1633b coal fly ash, NIST 1944 marine sediment and GBW 07312 stream sediments. The results obtained are in good agreement with the certified values and method is also applied to real samples.

  14. Mineralogical basis for the interpretation of multi-element (ICP-AES), oxalic acid, and aqua regia partial digestions of stream sediments for reconnaissance exploration geochemistry

    Science.gov (United States)

    Church, S.E.; Mosier, E.L.; Motooka, J.M.

    1987-01-01

    We have applied partial digestion procedures, primarily oxalic acid and aqua regia leaches, to several regional geochemical reconnaissance studies carried out using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) analytical methods. We have chosen to use these two acids because the oxalic acid primarily attacks those compounds formed during secondary geochemical processes, whereas aqua regia will digest the primary sulfide phases as well as secondary phases. Application of the partial digestion technique has proven superior to total digestion because the concentration of metals in hydromorphic compounds and the sulfides is enhanced relative to the metals bound in the unattacked silicate phases. The aqua regia digestion attacks and leaches metals from the mafic chain silicates and the phyllosilicates (coordination number of VI or more), yielding a characteristic geochemical signature, but does not leach appreciable metal from many other silicates. In order to interpret the results from these leach studies, we have initiated an investigation of a large suite of hand-picked mineral separates. The study includes analyses of about two hundred minerals representing the common rock-forming minerals as well as end-member compositions of various silicates, oxides, sulfides, carbonates, sulfates, and some vanadates, molybdates, tungstates, and phosphates. The objective of this study is to evaluate the effect of leaching by acids of particular lattice sites in specific mineral structures. ?? 1987.

  15. Effectiveness of indoor ultra-low volume application of Aqua Reslin® Super during an emergency.

    Science.gov (United States)

    Ordóñez González, José Genaro; Thirion, Jaime; García Orozco, Abel; Rodríguez, Américo D

    2011-06-01

    Indoor ultra-low volume (ULV) applications of Aqua Reslin Super (Permethrin + s-bioallethrin) were carried out using portable Solo Port 423 sprayers in an urban area of Reforma, Chiapas, Mexico. Sprayers were calibrated to discharge a flow rate of 110 ml/min with a dose range of approximately 0.55 to 0.792 mg Al/m3 space. Entomological evaluation, based on 3 cages per house, each containing 15 sugar-fed, 2-4-day-old Aedes aegypti females and placed in hidden locations in 4 randomly selected houses for 15 min, showed 98.8% to 100% mortality. After the spraying, ovitrap data showed no mosquito adults present 4 days after the applications, and only 1 ovitrap out of 60 positive 8 days after the intervention. This evaluation suggests that indoor ULV application can be useful during emergencies after disasters, during dengue outbreaks, or to prevent mosquito population outbreaks before rainy seasons and, therefore, the onset of dengue transmission in Mexican dengue transmission risk areas.

  16. Removal of the arsenic from contaminated groundwater with use of the new generation of MicroDrop Aqua system

    DEFF Research Database (Denmark)

    Kowalski, Krzysztof; Søgaard, Erik Gydesen

    2012-01-01

    The results from a new pilot scale plant of the MicroDrop Aqua arsenic removal technology are introduced. The technology is based on the employing of electrochemical iron dissolution and efficient aeration prior to sand filtration. The pilot treatment was used to study effectiveness of iron release...... in an electro-dissolution process that is taking place in an iron generator. It was found that there is a need of some extra time to reach a state of steady iron release and that could not be achieved within a short period of 10-20 minutes. The pilot plant proved to be able to remove arsenic to value below 5μg....../L and it has been shown that the process efficiency depends on the applied current. Moreover, it was found that iron accumulation in the sand filter had a positive effect on the arsenic removal activity and it shall be considered in future tests. The presented method enables efficiently, without chemical...

  17. High-Resolution Daily Flood Extent Depiction from Microwave Remote Sensing: Global Results

    Science.gov (United States)

    Galantowicz, J. F.

    2015-12-01

    The need for frequent, accurate, high-resolution characterization of the temporal and spatial progression of flood hazards is evident, but has been beyond the capabilities of remote sensing methods. The surface is too often obscured by cloud cover for visual and infrared sensors and observations from radar sensors are too infrequent to create consistent historical databases or for monitoring current conditions. Passive microwave sensors, such as SSM/I, AMSR-E, and AMSR-2, acquire useful data during clear and cloudy conditions, have revisit periods of up to twice daily, and provide a continuous record of data from 1987 to the present. In this presentation, we will describe results from a flood mapping system capable of producing high-resolution (100-m) flood extent depictions from lower resolution (10-40-km) microwave data. The system uses the strong sensitivity of microwave data to surface water extent combined with land surface and atmospheric data to derive daily flooded fraction estimates globally on a sensor footprint basis. The system downscales flooded fraction to make a high-resolution Boolean flood extent depiction that is both spatially continuous and consistent with the lower resolution data (see Figure). The downscaling step is based on a relative floodability index derived from higher resolution topographic and hydrological data and processed to represent the minimum total water fraction threshold above which each grid point is expected to be flooded given microwave-derived water fraction inputs. We have completed daily, 100-m resolution flood maps for Africa for the 9.3-year AMSR-E period and will soon complete global flood maps fo the same period. We will present animations of daily flood extents during major events and discuss: validation of the flood maps against imagery derived from MODIS and Landsat data; analyses of minimum detectable flood size; statistical analyses of flooding over time; applications for this novel historical dataset; and

  18. Remote Sensing Observations of Snow and Soil Moisture for Snowmelt Flood Predictions in the Red River of the North Basin

    Science.gov (United States)

    Tuttle, S. E.; Jacobs, J. M.; Vuyovich, C.; Cho, E.; Restrepo, P. J.; Jia, X.; Cosh, M. H.; Deweese, M. M.; Connelly, B.; Buan, S.

    2015-12-01

    The northward-flowing Red River of the North Basin (RRB), located in eastern North Dakota and western Minnesota, is vulnerable to frequent floods due to its flat terrain and low permeability soil. A vast majority of floods in the basin occur during the snowmelt season, when the winter snowpack thaws and spring rains fall onto saturated soils. This causes the Red River to spill over shallow banks and across the floodplain. The region has sparse in situ observations of snow and soil moisture, making flood prediction in the RRB difficult. Remote sensing data can help to capture magnitude, timing, and spatial distribution of watershed scale snow, soil moisture, and snowmelt parameters in the RRB, which will allow for better characterization of the watershed's hydrologic state. This research examines snow water equivalent (SWE; from the AMSR-E, AMSR2, and SSM/I satellite instruments), soil moisture (from AMSR-E, SMOS, and SMAP), and snow covered area (SCA; from MODIS), along with modeled SWE and snow depth from NOAA's National Operational Hydrologic Remote Sensing Center (NOHRSC) SNOw Data Assimilation System (SNODAS). These data are compared with observations from local and federal snow surveys, NOHRSC Airborne Gamma Radiation Snow Survey Program flights, NOAA National Climate Data Center (NCDC) cooperative network sites, Natural Resource Conservation Service (NRCS) Soil Climate Analysis Network (SCAN) sites, and the North Central River Forecast Center's (NCRFC) model states, in order to determine data quality as well as strengths and weaknesses of satellite observations for RRB flood forecasting. Future analyses will include evaluation of freeze/thaw state information from the Soil Moisture Active-Passive (SMAP) satellite, and explore the potential for flood forecasting improvement by updating state variables of the NOAA National Weather Service (NWS) operational forecasting models with remotely sensed fields.

  19. Assessment of the consistency among global microwave land surface emissivity products

    Directory of Open Access Journals (Sweden)

    H. Norouzi

    2014-09-01

    Full Text Available The goal of this work is to inter-compare a number of global land surface emissivity products over various land-cover conditions to assess their consistency. Ultimately, the discrepancies between the studied emissivity products will help interpreting the divergences among numerical weather prediction models in which land emissivity is a key surface boundary parameter. The intercompared retrieved land emissivity products were generated over five-year period (2003–2007 using observations from the Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E, Special Sensor Microwave Imager (SSM/I, The Tropical Rainfall Measuring Mission (TRMM Microwave Imager (TMI and Windsat. First, all products were reprocessed in the same projection and spatial resolution as they were generated from sensors with various configurations. Then, the mean value and standard deviations of monthly emissivity values were calculated for each product to assess the spatial distribution of the consistencies/inconsistencies among the products across the globe. The emissivity values from four products were also compared to soil moisture estimates and satellite-based vegetation index to assess their sensitivities to the changes in land surface conditions. Results show that systematic differences among products exist and variation of emissivities at each product has similar frequency dependency at any land cover type. Monthly means of emissivity values from AMSR-E in the vertical and horizontal polarizations seem to be systematically lower across various land cover condition which may be attributed to the 1.30 a.m./p.m. overpass time of the sensor and possibly a residual skin temperature effect in the product. The standard deviation of the analysed products was the lowest (less than 0.01 in rain forest regions for all products and the highest in northern latitudes, above 0.04 for AMSR-E and SSM/I and around 0.03 for WindSat. Despite differences in absolute

  20. Estimation of global snow cover using passive microwave data

    Science.gov (United States)

    Chang, Alfred T. C.; Kelly, Richard E.; Foster, James L.; Hall, Dorothy K.

    2003-04-01

    This paper describes an approach to estimate global snow cover using satellite passive microwave data. Snow cover is detected using the high frequency scattering signal from natural microwave radiation, which is observed by passive microwave instruments. Developed for the retrieval of global snow depth and snow water equivalent using Advanced Microwave Scanning Radiometer EOS (AMSR-E), the algorithm uses passive microwave radiation along with a microwave emission model and a snow grain growth model to estimate snow depth. The microwave emission model is based on the Dense Media Radiative Transfer (DMRT) model that uses the quasi-crystalline approach and sticky particle theory to predict the brightness temperature from a single layered snowpack. The grain growth model is a generic single layer model based on an empirical approach to predict snow grain size evolution with time. Gridding to the 25 km EASE-grid projection, a daily record of Special Sensor Microwave Imager (SSM/I) snow depth estimates was generated for December 2000 to March 2001. The estimates are tested using ground measurements from two continental-scale river catchments (Nelson River and the Ob River in Russia). This regional-scale testing of the algorithm shows that for passive microwave estimates, the average daily snow depth retrieval standard error between estimated and measured snow depths ranges from 0 cm to 40 cm of point observations. Bias characteristics are different for each basin. A fraction of the error is related to uncertainties about the grain growth initialization states and uncertainties about grain size changes through the winter season that directly affect the parameterization of the snow depth estimation in the DMRT model. Also, the algorithm does not include a correction for forest cover and this effect is clearly observed in the retrieval. Finally, error is also related to scale differences between in situ ground measurements and area-integrated satellite estimates. With AMSR-E

  1. Applicable evaluation of crop model AquaCrop for summer maize production in Loess Plateau Region%AquaCrop作物模型在黄土塬区夏玉米生产中的适用性评价

    Institute of Scientific and Technical Information of China (English)

    倪玲; 冯浩; 任小川; 郝志鹏

    2015-01-01

    In order to evaluate its applicability of crop model AquaCrop in Loess Plateau Region,the model parame-ters were revised and validated based on the summer maize parameters recommended by Hsiao et al .The biomass in the maize growing season,the change procedure of evapotranspiration,harvest yield and aboveground biomass in 2003, 2004,2005,2007,2008 and 2010 in Changwu Region of the Shaanxi Province have been simulated,and carried out the comparison and analysis for the simulated with measured data .The results were showed that:In the six years,the adjust-ed determination coefficient Adj .R2 for simulated yield data and measured yield data was 0 .9270,the relative error was between -2 .479 to 1 1 .182 .The Adj .R2 for simulated and measured aboveground biomass was 0 .7842 .In this model, the effect of simulating yield was better than the aboveground biomass .In 2005 and 2008,the Adj .R2 for simulated and measured evapotranspiration were 0 .6229 and 0 .7973,respectively .Therefore,this model has a good simulation effect and important significance for the next optimal water management of summer maize in Loess Plateau Region .%为评价AquaCrop作物模型在黄土塬区的适用性,基于Hsiao等人推荐的玉米参数对模型参数进行调试及验证。在陕西长武地区模拟2003、2004、2005、2007、2008、2010年玉米生育期内生物量、蒸发蒸腾量的变化过程及收获时产量、地上部生物量,将模拟值与收集到的实测值进行对比、分析。结果表明,这6年模拟产量与实测产量间的校正决定系数(Adj)R2为0.9270,相对误差在-2.479至11.182之间;模拟地上部生物量与实测地上部生物量间的Adj .R2为0.7842,模型对产量的模拟效果优于对生物量的模拟;2005年和2008年模拟蒸散量与实测蒸散量间的Adj .R2分别为0.6229和0.7973。模拟效果较好,对黄土塬区夏玉米水分优化管理模拟有重要意义。

  2. Multi-Decadal Variability of Polynya Characteristics and Ice Production in the North Water Polynya by Means of Passive Microwave and Thermal Infrared Satellite Imagery

    Directory of Open Access Journals (Sweden)

    Andreas Preußer

    2015-11-01

    Full Text Available The North Water (NOW Polynya is a regularly-forming area of open-water and thin-ice, located between northwestern Greenland and Ellesmere Island (Canada at the northern tip of Baffin Bay. Due to its large spatial extent, it is of high importance for a variety of physical and biological processes, especially in wintertime. Here, we present a long-term remote sensing study for the winter seasons 1978/1979 to 2014/2015. Polynya characteristics are inferred from (1 sea ice concentrations and brightness temperatures from passive microwave satellite sensors (Advanced Microwave Scanning Radiometer (AMSR-E and AMSR2, Scanning Multichannel Microwave Radiometer (SMMR, Special Sensor Microwave Imager/Sounder (SSM/I-SSMIS and (2 thin-ice thickness distributions, which are calculated using MODIS ice-surface temperatures and European Center for Medium-Range Weather Forecasts (ECMWF atmospheric reanalysis data in a 1D thermodynamic energy-balance model. Daily ice production rates are retrieved for each winter season from 2002/2003 to 2014/2015, assuming that all heat loss at the ice surface is balanced by ice growth. Two different cloud-cover correction schemes are applied on daily polynya area and ice production values to account for cloud gaps in the MODIS composites. Our results indicate that the NOW polynya experienced significant seasonal changes over the last three decades considering the overall frequency of polynya occurrences, as well as their spatial extent. In the 1980s, there were prolonged periods of a more or less closed ice cover in northern Baffin Bay in winter. This changed towards an average opening on more than 85% of the days between November and March during the last decade. Noticeably, the sea ice cover in the NOW polynya region shows signs of a later-appearing fall freeze-up, starting in the late 1990s. Different methods to obtain daily polynya area using passive microwave AMSR-E/AMSR2 data and SSM/I-SSMIS data were applied. A comparison

  3. 大面积水体上空星载微波辐射计的干扰识别%Identifying the Interference of Spaceborne Microwave Radiometer over Large Water Area

    Institute of Scientific and Technical Information of China (English)

    官莉; 夏仕昌; 张思勃

    2015-01-01

    卫星微波仪器接收的来自地气系统的被动热辐射与主动传感器发射的信号相混合,被称为无线电频率干扰(RFI),在主动及被动微波遥感探测领域已成为越来越严重的问题。海洋表面反射的静止通讯、电视卫星下发信号是干扰海洋上星载被动微波辐射计观测的主要来源。该文以先进的微波扫描辐射计 AMSR-E 为例,采用双主成分分析方法对美国陆地上大面积水体、附近洋面和中国海岸线附近的 RFI 进行识别,研究表明:美国附近洋面区域星载微波辐射计18.7 GHz 通道观测主要受静止电视卫星 DirecTV 的干扰,由于海表反射引起的 RFI 非常依赖于静止卫星和星载被动仪器的相对几何位置,只有当闪烁角θ(观测视场镜面反射的静止电视卫星信号方向与视场到星载仪器方向之间的夹角)较小时卫星观测易受到污染。美国海洋区域较强 RFI 分布在五大湖区域,离内陆越近RFI 越强,东西海岸 RFI 较强,而整个南海岸干扰相对较弱。中国海岸线附近 AMSR-E 6.925 GHz 通道观测受RFI 影响,而18.7 GHz 通道观测未受到干扰。%The phenomenon of satellite-measured passive microwave thermal emission from natural surface and atmosphere being mixed with signals from active sensors is referred as radio-frequency interference (RFI). Due to increasing conflicts between scientific and commercial users of the radio spectrum,RFI is an in-creasing serious problem for microwave active and passive remote sensing.RFI greatly affects the quality of data and retrieval products from space-borne microwave radiometry,as the C-band and X-band of space-borne microwave radiometer operate in unprotected frequency bands.Interference signals over land come dominantly from lower frequency active microwave transmitters,including radar,air traffic control,cell phone,garage door remote control,GPS signal on highway,defense tracking and

  4. AquaPedia: Building Intellectual Capacity Through Shared Learning and Open Access Platform to Resolve Water Conflicts

    Science.gov (United States)

    Islam, S.; Akanda, A. S.; Jutla, A.; Lin, C.; Gao, Y.

    2009-04-01

    consider the impact of natural factors (E, P, and Q) and coupling among them. We recognize that uncertainties and incomplete information about interconnections, feedbacks, and complexities within and between societal and natural systems will continue to pose high barriers in finding an effective solution and reaching an agreement for a given water conflict. Sharing of knowledge across river basins can catalyze this learning process. Yet, each water problem or conflict is usually highly contextual and local with different patterns of interconnections and complexities within and between societal and natural system. A management intervention that works in one basin may not be applicable to another due to differences in social-economic context and natural settings. Consequently, we need a conceptual framework that can integrate knowledge as well as compare and contrast outcomes across different scales, boundaries, and river basins. Such a framework will allow us to share knowledge and speed up the learning process across scales and boundaries. Our proposed web-based, wiki-style, self-learning repository of interactive and searchable water case studies, AquaPedia, is a step in that direction. This repository of water information and collective wisdom will bring together various stakeholders across the globe on a common platform to discuss and craft possible solution(s) for a conflict through joint fact finding and interactive learning. An open access collaborative model is adopted in AquaPedia so that stakeholders can participate in the creation, collaboration, discussion, and modification of the content in a meaningful way. The goal is to encourage and combine multiple perspectives and explore negotiated solutions to water conflicts.

  5. The comparison of MODIS-Aqua (C5 and CALIOP (V2 & V3 aerosol optical depth

    Directory of Open Access Journals (Sweden)

    J. Redemann

    2012-03-01

    Full Text Available We assess the consistency between instantaneously collocated level-2 aerosol optical depth (AOD retrievals from MODIS-Aqua (C5 and CALIOP (Version 2 & 3, comparing the standard MODIS AOD (MYD04_L2 data to the AOD calculated from CALIOP aerosol extinction profiles for both the previous release (V2 and the latest release (V3 of CALIOP data. Based on data collected in January 2007, we investigate the most useful criteria for screening the MODIS and CALIOP retrievals to achieve the best agreement between the two data sets. Applying these criteria to eight months of data (Jan, Apr, Jul, Oct 2007 and 2009, we find an order of magnitude increase for the CALIOP V3 data density (by comparison to V2, that is generally accompanied by equal or better agreement with MODIS AOD. Differences in global, monthly mean, over-ocean AOD (532 nm between CALIOP and MODIS range between 0.03 and 0.04 for CALIOP V3, with CALIOP generally biased low, when all available data from both sensors are considered. Root-mean-squares (RMS differences in instantaneously collocated AOD retrievals by the two instruments are reduced from values ranging between 0.14 and 0.19 using the unscreened V3 data to values ranging from 0.09 to 0.1 for the screened data. A restriction to scenes with cloud fractions less than 1% (as defined in the MODIS aerosol retrievals generally results in improved correlation (R2>0.5, except for the month of July when correlations remain relatively lower. Regional assessments show hot spots in disagreement between the two sensors in Asian outflow during April and off the coast of South Africa in July.

  6. 可见分光光度法测定水华鱼腥藻%The Measurement of Anabaena flos-aquae with Visible Spectrophotography

    Institute of Scientific and Technical Information of China (English)

    胡先文; 董元彦; 张新萍; 叶发兵

    2002-01-01

    采用可见分光光度法测定水华鱼腥藻(Anabaena flos-aquae)藻液的吸光度A.这种方法与细胞计数法、叶绿素a含量测定法和荧光分光光度法相比较,既简便又准确,且可获得十分理想的线性相关性,其测得的A值可以作为水华鱼腥藻现存量的指标.

  7. Estimating flooded area and mean water level using active and passive microwaves: the example of Paraná River Delta floodplain

    Directory of Open Access Journals (Sweden)

    M. Salvia

    2011-08-01

    Full Text Available This paper describes a procedure to estimate both the fraction of flooded area and the mean water level in vegetated river floodplains by using a synergy of active and passive microwave signatures. In particular, C band Envisat ASAR in Wide Swath mode and AMSR-E at X, Ku and Ka band, are used. The method, which is an extension of previously developed algorithms based on passive data, exploits also model simulations of vegetation emissivity. The procedure is applied to a long flood event which occurred in the Paraná River Delta from December 2009 to April 2010. Obtained results are consistent with in situ measurements of river water level.

  8. Estimating flooded area and mean water level using active and passive microwaves: the example of Paraná River Delta floodplain

    Directory of Open Access Journals (Sweden)

    M. Salvia

    2011-03-01

    Full Text Available This paper describes a procedure to estimate both the fraction of flooded area and the mean water level in vegetated river floodplains by using a synergy of active and passive microwave signatures. In particular, C Band Envisat ASAR in Wide Scan mode and AMSR-E at X, Ku and Ka Band, are used. The method, which is an extension of previously developed algorithms based on passive data, exploits also model simulations of vegetation emissivity. The procedure is applied to a long flood event which occurred in the Paraná River Delta from December 2009 to April 2010. Obtained results are consistent with in situ measurements of river water level.

  9. Potential Utility of the Real-Time TMPA-RT Precipitation Estimates in Streamflow Prediction

    Science.gov (United States)

    Su, Fengge; Gao, Huilin; Huffman, George J.; Lettenmaier, Dennis P.

    2010-01-01

    We investigate the potential utility of the real-time Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA-RT) data for streamflow prediction, both through direct comparisons of TMPA-RT estimates with a gridded gauge product, and through evaluation of streamflow simulations over four tributaries of La Plata Basin (LPB) in South America using the two precipitation products. Our assessments indicate that the relative accuracy and the hydrologic performance of TMPA-RT-based streamflow simulations generally improved after February 2005. The improvements in TMPA-RT since 2005 are closely related to upgrades in the TMPA-RT algorithm in early February, 2005 which include use of additional microwave sensors (AMSR-E and AMSU-B) and implementation of different calibration schemes. Our work suggests considerable potential for hydrologic prediction using purely satellite-derived precipitation estimates (no adjustments by in situ gauges) in parts of the globe where in situ observations are sparse.

  10. Using high-resolution soil moisture modelling to assess the uncertainty of microwave remotely sensed soil moisture products at the correct spatial and temporal support

    Science.gov (United States)

    Wanders, N.; Karssenberg, D.; Bierkens, M. F. P.; Van Dam, J. C.; De Jong, S. M.

    2012-04-01

    Soil moisture is a key variable in the hydrological cycle and important in hydrological modelling. When assimilating soil moisture into flood forecasting models, the improvement of forecasting skills depends on the ability to accurately estimate the spatial and temporal patterns of soil moisture content throughout the river basin. Space-borne remote sensing may provide this information with a high temporal and spatial resolution and with a global coverage. Currently three microwave soil moisture products are available: AMSR-E, ASCAT and SMOS. The quality of these satellite-based products is often assessed by comparing them with in-situ observations of soil moisture. This comparison is however hampered by the difference in spatial and temporal support (i.e., resolution, scale), because the spatial resolution of microwave satellites is rather low compared to in-situ field measurements. Thus, the aim of this study is to derive a method to assess the uncertainty of microwave satellite soil moisture products at the correct spatial support. To overcome the difference in support size between in-situ soil moisture observations and remote sensed soil moisture, we used a stochastic, distributed unsaturated zone model (SWAP, van Dam (2000)) that is upscaled to the support of different satellite products. A detailed assessment of the SWAP model uncertainty is included to ensure that the uncertainty in satellite soil moisture is not overestimated due to an underestimation of the model uncertainty. We simulated unsaturated water flow up to a depth of 1.5m with a vertical resolution of 1 to 10 cm and on a horizontal grid of 1 km2 for the period Jan 2010 - Jun 2011. The SWAP model was first calibrated and validated on in-situ data of the REMEDHUS soil moisture network (Spain). Next, to evaluate the satellite products, the model was run for areas in the proximity of 79 meteorological stations in Spain, where model results were aggregated to the correct support of the satellite

  11. Microwave emissivity of freshwater ice, Part II: Modelling the Great Bear and Great Slave Lakes

    CERN Document Server

    Mills, Peter

    2012-01-01

    Lake ice within three Advanced Microwave Scanning Radiometer on EOS (AMSR-E) pixels over the Great Bear and Great Slave Lakes have been simulated with the Canadian Lake Ice Model (CLIMo). The resulting thicknesses and temperatures were fed to a radiative transfer-based ice emissivity model and compared to the satellite measurements at three frequencies---6.925 GHz, 10.65 GHz and 18.7 GHz. Excluding the melt season, the model was found to have strong predictive power, returning a correlation of 0.926 and a residual of 0.78 Kelvin at 18 GHz, vertical polarization. Discrepencies at melt season are thought to be caused by the presence of dirt in the snow cover which makes the microwave signature more like soil rather than ice. Except at 18 GHz, all results showed significant bias compared to measured values. Further work needs to be done to determine the source of this bias.

  12. A new MODIS daily cloud free snow cover mapping algorithm on the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    XiaoDong Huang; XiaoHua Hao; QiSheng Feng; Wei Wang; TianGang Liang

    2014-01-01

    Because of similar reflective characteristics of snow and cloud, the weather status seriously affects snow monitoring using optical remote sensing data. Cloud amount analysis during 2010 to 2011 snow seasons shows that cloud cover is the major limitation for snow cover monitoring using MOD10A1 and MYD10A1. By use of MODIS daily snow cover products and AMSR-E snow wa-ter equivalent products (SWE), several cloud elimination methods were integrated to produce a new daily cloud free snow cover product, and information of snow depth from 85 climate stations in Tibetan Plateau area (TP) were used to validate the accuracy of the new composite snow cover product. The results indicate that snow classification accuracy of the new daily snow cover product reaches 91.7%when snow depth is over 3 cm. This suggests that the new daily snow cover mapping algorithm is suitable for monitoring snow cover dynamic changes in TP.

  13. Multi sensor validation and error characteristics of Arctic satellite sea surface temperature observations

    DEFF Research Database (Denmark)

    Høyer, Jacob L.; Karagali, Ioanna; Tonbo, Rasmus;

    2012-01-01

    Six of the operational global satellite sea surface temperature products from infrared and microwave sensors are validated in a consistent way in waters north of 60° N. The 15-month validation with drifting buoy in situ observations shows that data from the Advanced Along-Tracking Scanning...... satellite have superior coverage due to the microwaves' ability to penetrate cloud cover. The performance of the different satellite products is examined for variation with season, water temperature, solar elevation angle, and proximity to the marginal ice zone. The validation results identify errors...... scales between 300 and 500 km. The error cross correlations between the different satellite products reveal that the products from the infrared sensors generally show significant error correlation, whereas the errors of the microwave AMSR-E product have a low correlation with all the products from...

  14. Satellite soil moisture for advancing our understanding of earth system processes and climate change

    Science.gov (United States)

    Dorigo, Wouter; de Jeu, Richard

    2016-06-01

    Soil moisture products obtained from active and passive microwave satellites have reached maturity during the last decade (De Jeu and Dorigo, 2016): On the one hand, research algorithms that were initially applied to sensors designed for other purposes, e.g., for measuring wind speed (e.g. the Advanced Scatterometer (ASCAT)), sea ice, or atmospheric parameters (e.g. the TRMM Microwave Imager (TMI) and the Advanced Microwave Scanning Radiometer - Earth Observing System AMSR-E), have developed into fully operational products. On the other hand, dedicated soil moisture satellite missions were designed and launched by ESA (the Soil Moisture Ocean Salinity (SMOS) mission) and NASA (the Soil Moisture Active Passive (SMAP) mission).

  15. Soil moisture at watershed scale: Remote sensing techniques

    Science.gov (United States)

    Fang, Bin; Lakshmi, Venkat

    2014-08-01

    Soil moisture at high spatial resolution is required for various land processes related studies. However, currently the resolution of passive microwave retrieved soil moisture is low - around 25 km. To solve this problem, a soil moisture disaggregation algorithm based on thermal inertia relationship between daily temperature change and average soil moisture modulated by vegetation conditions has been formulated. This algorithm was applied to the AMSR-E (Advanced Microwave Scanning Radiometer - Earth Observing System) as well as SMOS (Soil Moisture and Ocean Salinity satellite) to produce the 1 km downscaled soil moisture over the Little Washita Watershed in Oklahoma for the growing season in 2010 and 2011.The disaggregated soil moisture has been compared to in situ observations. The results of this approach are very encouraging.

  16. Improving Curve Number storm runoff estimates using passive microwave satellite observations

    Science.gov (United States)

    Beck, H. E.; Schellekens, J.; de Jeu, R. A. M.; van Dijk, A. I. J. M.; Bruijnzeel, L. A.

    2009-04-01

    This study investigated the potential for improvement of Soil Conservation Service (SCS) Curve Number (CN) storm runoff estimates with the implementation of satellite-derived soil moisture. A large data-set (1980-2007) of daily measurements of precipitation and streamflow for 135 Australian catchments ranging in size from 53 to 471 km2 was used. The observed CN, a measure of the soil's maximum potential retention, was calculated using the SCS-CN model from measured precipitation and stormflow data. The observed CN was compared to a soil wetness index (SWI) based on AMSR-E satellite surface moisture and an antecedent precipitation index (API) based on field observations. Significant correlations (p

  17. Hemoglobin levels and quality of life in patients with symptomatic chemotherapy-induced anemia: the eAQUA study

    Science.gov (United States)

    Mouysset, Jean-Loup; Freier, Beata; van den Bosch, Joan; Levaché, Charles Briac; Bols, Alain; Tessen, Hans Werner; Belton, Laura; Bohac, G Chet; Terwey, Jan-Henrik; Tonini, Giuseppe

    2016-01-01

    Purpose To assess hemoglobin (Hb) outcomes and fatigue-related quality-of-life (QoL) (electronic assessment) in patients with solid tumors and symptomatic chemotherapy-induced anemia receiving cytotoxic chemotherapy and darbepoetin alfa (DA) or another erythropoiesis-stimulating agent according to European indication. Methods eAQUA was a Phase IV prospective observational study. The primary outcome (assessed in the primary analysis set [PAS]: patients receiving one or more DA dose who had baseline and week 9 assessments for Hb and QoL) was the proportion of patients receiving DA having both Hb increases ≥1 g/dL and improved QoL between baseline and week 9. Functional Assessment of Cancer Therapy-Fatigue (FACT-F) subscale scores were anchored to fatigue visual analog scale scores to determine the minimally important difference for improved QoL. Overall data/data over time are reported for the full analysis set (patients receiving one or more erythropoiesis-stimulating agent dose, n=1,158); week 9 data (ie, data relating to the primary and secondary outcomes) are reported for the PAS (n=510). Baseline and safety data are included for both the full analysis set and PAS. Results In the PAS, 69% of patients had stage IV disease and 96% were fatigued. The minimally important difference in FACT-F change score for QoL improvement was 3.5. From baseline to week 9, 32% (95% confidence interval: 28%–36%) of patients had both improved QoL and an Hb increase ≥1 g/dL; proportions were similar across the most common tumor types. At week 9, 49% and 58% of patients had improved QoL or Hb increases ≥1 g/dL, respectively; 70% and 76% had QoL or Hb improvements between baseline and study end, respectively. In the PAS, 16% of patients required transfusions and 32% required iron supplementation. Few patients (<1%) reported adverse drug reactions. Conclusion In this study, patients with solid tumors receiving DA per European indication for symptomatic chemotherapy-induced anemia

  18. Determination of Trace Cadmium in Geological Samples by Aerosol Dilution ICP-MS with Inverse Aqua Regia Extraction

    Science.gov (United States)

    Xu, Q.; Guo, W.; Jin, L.; Hu, S.; Chai, X.

    2015-12-01

    Cadmium (Cd) is a trace element that occurs at ppb level in most terrestrial materials. The determination of Cd in geological samples by ICP-MS is subject to Zr and/or Mo based oxide/hydroxide interference. This study developed a valid method for the determination of Cd by Ar aerosol dilution ICP-MS with inverse aqua regia extraction (in a water bath at 95℃ for 2h). An Agilent 7700x ICP-MS (Agilent Technologies, USA) with an aerosol dilution system was used. The extraction procedure separated most of the Zr matrix (>90%) from the analyte, and the residual Zr- hydroxides and Mo-oxides or hydroxides were successfully eliminated by adding an amount of Ar to the sample aerosol prior to the plasma. Compared to the conventional operation, the amounts of oxide and hydroxide ions formed in the plasma were reduced by up to 10 times. The relative yields of the interfering oxides and hydroxides were as low as 0.012% ((94Mo16OH++95Mo16O+)/(94Mo++95Mo+)) and 0.007% (94Zr16OH+/94Zr+). Under the optimized dilution gas flow rate (0.85 L min-1) and carrier gas flow rate (0.24 L min-1), the limit of detection (LOD, 3s) for 111Cd was 1.3 ng g-1. The accuracy of the method was assessed by using two USGS SRMs (andesite AGV-2 and basalt BCR-2). The Cd contents determined for AGV-2 and BCR-2 are 0.058±0.004μg g-1 and 0.148±0.007μg g-1 (N=10), which are in good agreement with the USGS reference values (0.061μg g-1 and 0.14μg g-1). The proposed method was also applied to determine Cd contents in 65 IGGE SRMs (28 soils, 28 sediments and 9 rocks). The measured Cd levels in these samples agree well with their certified values. The developed method shows great potential for the direct determination of trace levels of Cd in geological samples.

  19. Comparison of Reflected Solar Radiance Using Aqua Modis and Airborne Remote Sensing (case : Deep Convective Clouds and Cirrus Clouds)

    Science.gov (United States)

    Krisna, T. C.; Ehrlich, A.; Werner, F.; Wendisch, M.

    2015-12-01

    Deep Convective Clouds (DCCs) have key role in the tropical region. Despite they only have small spatial coverage, but they account most of the total precipitation in these region which often make flooding. There are such of aviation accidents caused by strong vertical wind, hailing, icing and lightning inside the clouds. Pollutions caused by biomass burning and land degradation can change the aerosol properties as well as cloud properties, therefore will influence the radiation and formation of the DCCs. Those are the major reasons that better understanding of DCCs formation and life cycle are necessary. Between Sept. 01 - Oct. 14, ACRIDICON (Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Concevtive Clouds Systems) campaign was conducted over Amazonia. It is suitable area to be the site-study due to has strong contrast environtment (pristine and polluted), regular convection activities and stable meteorological condition. In this study we focus on the 2 satellite validation missions designed to fly collocated but in different altitude with A-TRAIN constellation. In order to study DCCs-solar radiation interaction, we use SMART (Spectral Modular Airborne Radiation Measurements System) installed on HALO (High Altitude and Long-Range Research Aircraft) which measures spectral Irradiance (F) and Radiance (I) at the wavelength between 300-2200 nm corresponding to satellite. Due to the limitation in spatial and temporal, airborne measurements only give snapshots of atmosphere condition and DCCs formation, therefore we use multi-satellite data as DCCs have high vertical and horizontal distance, long temporal development and complex form. The comparison of AQUA MODIS and SMART Radiance at 645 nm (non-absorbing) in the clear-sky condition gives strong agreement, but in the multilayer-cloud condition gives worse and results in high underestimation (-86%) in SMART data especially at lower altitude. The bias is caused by interference from clouds

  20. Developing a virtual sensor (VS) for mapping soil moisture at high spatial and temporal resolution

    Science.gov (United States)

    Hossain, A. K. M. Azad

    Mapping soil moisture at both high spatial and temporal resolution has not been possible due to lack of sensors with these combined capabilities. We transformed the Moderate Resolution Imaging Spectroradiometer (MODIS) into a virtual sensor (VS) for quantitative soil moisture mapping and monitoring at 1 km and 250 m resolution daily. The Vegetation Index (VI) - Land Surface Temperature (LST) triangle model was used as the governing algorithm for VS. We used a time series of 13 data sets from August 01, 2006 to November 06, 2006 of MODIS reflective and thermal imagery and AMSR-E Level 3 soil moisture imagery to develop the VS in the semi-arid environment of southeastern New Mexico. We used Synthetic Aperture Radar (SAR) derived soil moisture imagery for five corresponding dates of the MODIS/AMSR-E imagery to evaluate the performance of VS for soil moisture estimation along with near real time in situ soil moisture measurements. In situ soil moisture measurements, vegetation density/distribution maps, digital elevation model (DEM), soil type map and soil salinity measurements were used in both linear and non-linear numerical models with the Radarsat 1 SAR fine imagery. The numerical models based on multiple linear regressions improved soil moisture estimation for the entire study site. We found, however, that vegetation, soil type and elevation have stronger combined effect on microwave soil moisture remote sensing by non-linear regressions (neural networks). The accuracy of the soil moisture data was evaluated using Kappa statistics. A soil moisture prediction surface prepared by kriging the in situ soil moisture 2 measurements was used as the reference. We obtained the overall accuracy of 75.67% and 77.67% with a Kappa coefficient of 0.43 and 0.61 for the August 02 and November 06 data sets of 2006, respectively. We evaluated the application of VS generated soil moisture data in mapping the spatio-temporal variation in soil moisture in southeastern New Mexico. The

  1. Evaluation of the AquaCrop model for simulating biomass for Chinese green onion and soil water storage%AquaCrop模型在大葱生物量和土壤贮水量模拟中的应用和验证

    Institute of Scientific and Technical Information of China (English)

    李子忠; 徐洋; 卢宪菊; 胡克林; 江丽华; 徐钰

    2011-01-01

    为评估AquaCrop模型在华北平原模拟大葱生长和农田水分的适用性,本研究利用实测的农民施肥方式的一个小区和增施氮肥处理的土壤水分、作物生长和产量数据,结合气象资料,获得了AquaCrop模型模拟大葱生长和土壤水分的模型参数,并利用实测的农民施肥方式的另外一个小区、减施氮肥、优化施氮和秸秆还田处理的土壤贮水量和生物量数据进行了模型验证。结果表明:在无水分胁迫条件下AquaCrop模型对大葱土壤贮水量及生物量的模拟结果是可以接受的。对土壤贮水量实测值与模拟值的RMSE为19.4~24.9 mm之间,相对误差%The objective of this study was to evaluate the AquaCrop model for Chinese green onion for simulating the growth and soil water storage in North China Plain.AquaCrop model for Chinese green onion was parameterized using soil water data,crop growth and yield data from one plot of Farmer Practice and Heavy Nitrogen Application treatments and the weather data,and tested using data from another plot of Farmer Practice,reduced nitrogen application,optimized nitrogen application and straw returning treatments in 2009.The results showed that AquaCrop model simulated accurately the soil water storage and biomass without water stress condition.The RMSE between the simulated soil water storage values and measurements was 19.4-24.9 mm,the relative error 3.9%-12.4%.The RMSE between the simulated biomass values and measurements was 0.31-0.73 t/hm2,the relative error 5.8%-12.8%.

  2. Prediksi Zona Tangkapan Ikan Menggunakan Citra Klorofil-a Dan Citra Suhu Permukaan Laut Satelit Aqua MODIS Di Perairan Pulo Aceh

    Directory of Open Access Journals (Sweden)

    Mursyidin Mursyidin

    2015-12-01

    prediction of fishing zone can be done by detecting chlorophyll-a and sea surface temperature distribution of Aqua MODIS Imagery. The aim of this study is to predict fishing zone on the waters of Pulo Aceh based on the chlorophyll distribution and sea surface temperature by utilizing the data of Aqua MODIS Satellite Imagery level 3. The stages of this study included collecting imagery, cutting the image according to the desired area, giving lands mark to display a more informative image, extracting information of chlorophyll-a and the distribution of sea surface temperature, and interpolating by using Kriging method. The highest distribution of chlorophyll-a happened in June and August, the spread moved from the the North Pulo Aceh to the South. The distribution of sea surface temperature that suitable for fishing was detected in August around the North Ujung Pulo Breuh and around pulau Keureusik. The potential zone of fishing on the waters of Pulo Aceh was only detected in August in the eastern of pulau Keureusik to Ujong Keumuroh. Pulo Aceh waters is suitable for fishing destination in August.

  3. Experiment on Development of 30% Glyphosate Ammonium Salt Water Aqua%30%草甘膦铵盐水剂研制试验

    Institute of Scientific and Technical Information of China (English)

    余洋

    2012-01-01

    30%草甘膦铵盐水剂研制试验结果表明,低含量草甘膦母液通过除甲醛、浓缩制得30%草甘膦铵盐水剂,经测定,研制的样品质量稳定,甲醛含量〈10 g/kg,热贮(54℃±2℃)14 d分解率〈5%,符合国家规定的30%草甘膦铵盐水剂标准。%The experiment on development of 30% glyphosate ammonium salt water aqua results showed that by removing the low content of glyphosate mother liquor of formaldehyde and concentration, 30% ammonium salt glyphosate water aqua was acquired. Storage stability tests showed that the decomposition rate of the active ingredient was less than 5% at (54±2)℃ for 14 days and formaldehyde content was less than 10 g/kg.The physical and chemical properties of the formulated product confirmed to the requirements of EW formulation.

  4. Removal of Anabaena flos-aquae in water treatment process using Moringa oleifera and assessment of fatty acid profile of generated sludge.

    Science.gov (United States)

    Moreti, Livia O R; Coldebella, Priscila Ferri; Camacho, Franciele P; Carvalho Bongiovani, Milene; Pereira de Souza, Aloisio Henrique; Kirie Gohara, Aline; Matsushita, Makoto; Fernandes Silva, Marcela; Nishi, Letícia; Bergamasco, Rosângela

    2016-01-01

    This study aimed to evaluate the efficiency of the coagulation/flocculation/dissolved air flotation (C/F/DAF) process using the coagulant Moringa oleifera (MO) seed powder, and to analyse the profile of fatty acids present in the generated sludge after treatment. For the tests, deionized water artificially contaminated with cell cultures of Anabaena flos-aquae was used, with a cell density in the order of 10(4) cells mL(-1). C/F/DAF tests were conducted using 'Flotest' equipment. For fatty acid profile analyses, a gas chromatograph equipped with a flame ionization detector was used. It was seen that the optimal dosage (100 mg L(-1)) of MO used in the C/F/DAF process was efficient at removing nearly all A. flos-aquae cells (96.4%). The sludge obtained after treatment contained oleic acid (61.7%) and palmitic acid (10.8%). Thus, a water treatment process using C/F/DAF linked to integral MO powder seed was found to be efficient in removing cells of cyanobacteria, and produced a sludge rich in oleic acid that is a precursor favourable for obtaining quality biodiesel, thus becoming an alternative application for the recycling of such biomass.

  5. Removal of Anabaena flos-aquae in water treatment process using Moringa oleifera and assessment of fatty acid profile of generated sludge.

    Science.gov (United States)

    Moreti, Livia O R; Coldebella, Priscila Ferri; Camacho, Franciele P; Carvalho Bongiovani, Milene; Pereira de Souza, Aloisio Henrique; Kirie Gohara, Aline; Matsushita, Makoto; Fernandes Silva, Marcela; Nishi, Letícia; Bergamasco, Rosângela

    2016-01-01

    This study aimed to evaluate the efficiency of the coagulation/flocculation/dissolved air flotation (C/F/DAF) process using the coagulant Moringa oleifera (MO) seed powder, and to analyse the profile of fatty acids present in the generated sludge after treatment. For the tests, deionized water artificially contaminated with cell cultures of Anabaena flos-aquae was used, with a cell density in the order of 10(4) cells mL(-1). C/F/DAF tests were conducted using 'Flotest' equipment. For fatty acid profile analyses, a gas chromatograph equipped with a flame ionization detector was used. It was seen that the optimal dosage (100 mg L(-1)) of MO used in the C/F/DAF process was efficient at removing nearly all A. flos-aquae cells (96.4%). The sludge obtained after treatment contained oleic acid (61.7%) and palmitic acid (10.8%). Thus, a water treatment process using C/F/DAF linked to integral MO powder seed was found to be efficient in removing cells of cyanobacteria, and produced a sludge rich in oleic acid that is a precursor favourable for obtaining quality biodiesel, thus becoming an alternative application for the recycling of such biomass. PMID:26586082

  6. Evaluation of the AquaCrop model for simulating yield response of winter wheat to water on the southern Loess Plateau of China.

    Science.gov (United States)

    Zhang, Wanhong; Liu, Wenzhao; Xue, Qingwu; Chen, Jie; Han, Xiaoyang

    2013-01-01

    The objective of this study was to evaluate the performance of the FAO-AquaCrop model in winter wheat in the southern Loess Plateau of China. Multi-year field experimental data from 2004 and 2011 were used to calibrate and validate the model for simulating biomass, canopy cover (CC), soil water content, and grain yield under rainfed conditions. The model performance was evaluated using root mean square error (RMSE) and Willmott index of agreement (d) as criteria. The RMSE ranged from 0.16 to 0.38 t/ha for simulating aboveground biomass, 1.87 to 4.15% for CC, 0.50 to 1.44 t/ha for grain yield, and 5.70 to 22.56 mm for soil water content. The d ranged from 0.22 to 0.89, 0.25 to 0.43, 0.36 to 0.62 and 0.95 to 0.98 for aboveground biomass, CC, soil water content and grain yield, respectively. Generally, the model performed better for simulating CC and yield than biomass and soil water content. The results further indicated that AquaCrop is capable of simulating winter wheat yield under rainfed conditions. Further improvement may be needed to capture the variation of different management practices such as fertility and irrigation levels in this region.

  7. A Semi-Analytic Model for Estimating Total Suspended Sediment Concentration in Turbid Coastal Waters of Northern Western Australia Using MODIS-Aqua 250 m Data

    Directory of Open Access Journals (Sweden)

    Passang Dorji

    2016-06-01

    Full Text Available Knowledge of the concentration of total suspended sediment (TSS in coastal waters is of significance to marine environmental monitoring agencies to determine the turbidity of water that serve as a proxy to estimate the availability of light at depth for benthic habitats. TSS models applicable to data collected by satellite sensors can be used to determine TSS with reasonable accuracy and of adequate spatial and temporal resolution to be of use for coastal water quality monitoring. Thus, a study is presented here where we develop a semi-analytic sediment model (SASM applicable to any sensor with red and near infrared (NIR bands. The calibration and validation of the SASM using bootstrap and cross-validation methods showed that the SASM applied to Moderate Resolution Imaging Spectroradiometer (MODIS-Aqua band 1 data retrieved TSS with a root mean square error (RMSE and mean averaged relative error (MARE of 5.75 mg/L and 33.33% respectively. The application of the SASM over our study region using MODIS-Aqua band 1 data showed that the SASM can be used to monitor the on-going, post and pre-dredging activities and identify daily TSS anomalies that are caused by natural and anthropogenic processes in coastal waters of northern Western Australia.

  8. Simulation of water use process by film mulched cultivated maize based on improved AquaCrop model and its verification%基于改进AquaCrop模型的覆膜栽培玉米水分利用过程模拟与验证

    Institute of Scientific and Technical Information of China (English)

    杨宁; 孙占祥; 张立桢; 郑家明; 冯良山; 李开宇; 张哲; 冯晨

    2015-01-01

    为应用 AquaCrop 模型模拟覆膜玉米水分利用与产量形成过程,该文根据玉米发育阶段生长度日恒定原理,利用地积温对气积温的补偿效应,改进AquaCrop模型对覆膜玉米的气温计算方法,并根据2011年的生育期、耗水量和产量实测数据对改进模型参数进行校正,依据2012年与2013年的冠层覆盖度、土体贮水量、产量与水分利用效率试验数据对改进模型验证。结果表明,玉米地膜覆盖地积温对气积温的量化补偿系数(Cm):播种-出苗为1.356,出苗-抽雄前为0.635;校正改进的AquaCrop模型能够较好地模拟覆膜与裸地玉米生育天数、作物耗水量、籽粒产量,相对误差(Pe)、模型效率(CE)、残差系数(CRM)变幅分别为:-4%0.88, CE>0.87,0.090.8), the raised soil temperature in the mulched maize field was remarkable before tasseling stage. The compensatory coefficient (Cmaize) of mulching plastic film maize and air increment of cumulative soil temperature to cumulative air temperature can be generated continuously by transparent algorithms, which Cmaize was 1.356 from sowing to emergence, 0.635 from emergence to tasseling stage, and 0 after flowing. Furthermore, mean daily air temperature with the addition of air increment formed a new file (*.tmp) and input to AquaCrop’s climate module which can modify by function could be applied to mulching plastic film maize growing. Model coefficient of efficiency (CE), coefficient of determination (R2), the relative root mean square error (RRMSE), prediction error (Pe) and coefficient of residual mass (CRM) were used to test the model performance. The developed AquaCrop model was calibrated for simulating maize growing days, water consumption and grain yield for mulched and no-mulched maize with the prediction error statistics-4%0.88, 0.090.87. Upon validation, the Pe in simulation of water consumption and grain yield under mulched and no

  9. Japanese Global Precipitation Measurement (GPM) mission status and application of satellite-based global rainfall map

    Science.gov (United States)

    Kachi, Misako; Shimizu, Shuji; Kubota, Takuji; Yoshida, Naofumi; Oki, Riko; Kojima, Masahiro; Iguchi, Toshio; Nakamura, Kenji

    2010-05-01

    As accuracy of satellite precipitation estimates improves and observation frequency increases, application of those data to societal benefit areas, such as weather forecasts and flood predictions, is expected, in addition to research of precipitation climatology to analyze precipitation systems. There is, however, limitation on single satellite observation in coverage and frequency. Currently, the Global Precipitation Measurement (GPM) mission is scheduled under international collaboration to fulfill various user requirements that cannot be achieved by the single satellite, like the Tropical Rainfall Measurement Mission (TRMM). The GPM mission is an international mission to achieve high-accurate and high-frequent rainfall observation over a global area. GPM is composed of a TRMM-like non-sun-synchronous orbit satellite (GPM core satellite) and constellation of satellites carrying microwave radiometer instruments. The GPM core satellite carries the Dual-frequency Precipitation Radar (DPR), which is being developed by the Japan Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT), and microwave radiometer provided by the National Aeronautics and Space Administration (NASA). Development of DPR instrument is in good progress for scheduled launch in 2013, and DPR Critical Design Review has completed in July - September 2009. Constellation satellites, which carry a microwave imager and/or sounder, are planned to be launched around 2013 by each partner agency for its own purpose, and will contribute to extending coverage and increasing frequency. JAXA's future mission, the Global Change Observation Mission (GCOM) - Water (GCOM-W) satellite will be one of constellation satellites. The first generation of GCOM-W satellite is scheduled to be launched in 2011, and it carries the Advanced Microwave Scanning Radiometer 2 (AMSR2), which is being developed based on the experience of the AMSR-E on EOS Aqua satellite

  10. Validation of MODIS liquid water path for oceanic nonraining warm clouds: Implications on the vertical profile of cloud water content

    Science.gov (United States)

    Zhou, Lingli; Liu, Qi; Liu, Dongyang; Xie, Lei; Qi, Lin; Liu, Xiantong

    2016-05-01

    Liquid water path (LWP) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) is validated using the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) retrievals for global oceanic nonraining warm clouds, with focus on the vertically homogeneous (VH) model and adiabatically stratified (AS) model of liquid water content (LWC) profile used in MODIS retrieval. With respect to AMSR-E LWP that acts as ground truth under a series of constraints, the global average of MODIS-LWPVH and MODIS-LWPAS has a positive (11.8%) and negative (-6.8%) bias, respectively. Most of the oceanic warm clouds tend to have adiabatic origin and correspondingly form AS-like profiles, which could be well retained if drizzle is absent. Besides, the presence of drizzle, cloud top entrainment seems to be another cause that modifies the original LWC profiles to become VH-like, which is notable for the very low clouds that have rather small thickness. These factors jointly determine the appearance of LWP profiles and in turn their spatial pattern across global oceans, with AS-like profiles dominant in the areas where nonraining warm clouds occur very frequently in the form of stratocumulus. The modified MODIS LWP shows significant improvement compared with either MODIS-LWPVH or MODIS-LWPAS. This is achieved by using the two physically explicit models flexibly, in which the elementary MODIS retrievals of cloud top temperature, cloud optical thickness, and droplet effective radius play a determinant role. A combined use of VH and AS model in the MODIS retrieval is demonstrated to be effective for improving the LWP estimation for oceanic nonraining warm clouds.

  11. Evaluating the Utility of Remotely-Sensed Soil Moisture Retrievals for Operational Agricultural Drought Monitoring

    Science.gov (United States)

    Bolten, John D.; Crow, Wade T.; Zhan, Xiwu; Jackson, Thomas J.; Reynolds,Curt

    2010-01-01

    Soil moisture is a fundamental data source used by the United States Department of Agriculture (USDA) International Production Assessment Division (IPAD) to monitor crop growth stage and condition and subsequently, globally forecast agricultural yields. Currently, the USDA IPAD estimates surface and root-zone soil moisture using a two-layer modified Palmer soil moisture model forced by global precipitation and temperature measurements. However, this approach suffers from well-known errors arising from uncertainty in model forcing data and highly simplified model physics. Here we attempt to correct for these errors by designing and applying an Ensemble Kalman filter (EnKF) data assimilation system to integrate surface soil moisture retrievals from the NASA Advanced Microwave Scanning Radiometer (AMSR-E) into the USDA modified Palmer soil moisture model. An assessment of soil moisture analysis products produced from this assimilation has been completed for a five-year (2002 to 2007) period over the North American continent between 23degN - 50degN and 128degW - 65degW. In particular, a data denial experimental approach is utilized to isolate the added utility of integrating remotely-sensed soil moisture by comparing EnKF soil moisture results obtained using (relatively) low-quality precipitation products obtained from real-time satellite imagery to baseline Palmer model runs forced with higher quality rainfall. An analysis of root-zone anomalies for each model simulation suggests that the assimilation of AMSR-E surface soil moisture retrievals can add significant value to USDA root-zone predictions derived from real-time satellite precipitation products.

  12. A Sample of What We Have Learned from A-Train Cloud Measurements

    Science.gov (United States)

    Joiner, Joanna; Vasilkov, Alexander; Ziemke, Jerry; Chandra, Sushil; Spurr, Robert; Bhartia, P. K.; Krotkov, Nick; Sneep, Maarten; Menzel, Paul; Platnick, Steve; Stephens, Graeme; Wennberg, Paul; Avery, Melody; Wentz, Frank; Vanbaunce, Claudine; Pilewski, Peter; Diskin, Glenn; Vay, Stephanie

    2008-01-01

    The A-train active sensors CloudSat and CALIPSO provide detailed information about cloud vertical structure. Coarse vertical information can also be obtained from a combination of passive sensors (e.g. cloud liquid water content from AMSR-E, cloud ice properties from MLS and HIRDLS, cloud-top pressure from MODIS and AIRS, and UVNISINear IR absorption and scattering from OMI, MODIS, and POLDER). In addition, the wide swaths of instruments such as MODIS, AIRS, OMI, POLDER, and AMSR-E can be exploited to create estimates of the three-dimensional cloud extent. We will show how data fusion from A-train sensors can be used, e.g., to detect and map the presence of multiple layer/phase clouds. Ultimately, combined cloud information from Atrain instruments will allow for estimates of heating and radiative flux at the surface as well as UV/VIS/Near IR trace-gas absorption at the overpass time on a near-global daily basis. CloudSat has also dramatically improved our interpretation of visible and UV passive measurements in complex cloudy situations such as deep convection and multiple cloud layers. This has led to new approaches for unique and accurate constituent retrievals from A-train instruments. For example, ozone mixing ratios inside tropical deep convective clouds have recently been estimated using the Aura Ozone Monitoring Instrument (OMI). Field campaign data from TC4 provide additional information about the spatial variability and origin of trace-gases inside convective clouds. We will highlight some of the new applications of remote sensing in cloudy conditions that have been enabled by the synergy between the A-train active and passive sensors.

  13. Modelling soil moisture at SMOS scale by use of a SVAT model over the Valencia Anchor Station

    Directory of Open Access Journals (Sweden)

    S. Juglea

    2010-01-01

    Full Text Available The main goal of the SMOS (Soil Moisture and Ocean Salinity mission is to deliver global fields of surface soil moisture and sea surface salinity using L-band (1.4 GHz radiometry. Within the context of the preparation for this mission over land, the Valencia Anchor Station experimental site, in Spain, was chosen to be one of the main test sites in Europe for the SMOS Calibration/Validation (Cal/Val activities. Ground and meteorological measurements over the area are used as the input of a Soil-Vegetation-Atmosphere-Transfer (SVAT model, SURFEX (Externalized Surface-module ISBA (Interactions between Soil-Biosphere-Atmosphere so as to simulate the surface soil moisture. The calibration as well as the validation of the ISBA model was made using in situ soil moisture measurements. It is shown that a good consistency was reached when point comparisons between simulated and in situ soil moisture measurements were made. In order to obtain an accurate soil moisture mapping over the Valencia Anchor Station (50×50 km2 area, a spatialization method has been applied. To validate the approach, a comparison with remote sensing data from the Advanced Microwave Scanning Radiometer on Earth observing System (AMSR-E and from the European Remote Sensing Satellites (ERS-Scat was performed. Despite the fact that AMSR-E surface soil moisture product is not reproducing accurately the absolute values, it provides trustworthy information on surface soil moisture temporal variability. However, during the vegetation growing season the signal is perturbed. By using the polarization ratio a better agreement is obtained. ERS-Scat soil moisture products were also used to be compared with the simulated spatialized soil moisture. The seasonal variations were well reproduced. However, the lack of soil moisture data over the area (45 observations for one year was a limit into completely understanding the soil moisture variability.

  14. Analyzing signatures of aerosol-cloud interactions from satelliteretrievals and the GISS GCM to constrain the aerosol indirecteffect

    Energy Technology Data Exchange (ETDEWEB)

    Menon, S.; Del Genio, A.D.; Kaufman, Y.; Bennartz, R.; Koch, D.; Loeb, N.; Orlikowski, D.

    2007-10-01

    Evidence of aerosol-cloud interactions are evaluated using satellite data from MODIS, CERES, AMSR-E, reanalysis data from NCEP and data from the NASA Goddard Institute for Space Studies climate model. We evaluate a series of model simulations: (1) Exp N- aerosol direct radiative effects; (2) Exp C- Like Exp N but with aerosol effects on liquid-phase cumulus and stratus clouds; (3) Exp CN- Like Exp C but with model wind fields nudged to reanalysis data. Comparison between satellite-retrieved data and model simulations for June to August 2002, over the Atlantic Ocean indicate the following: a negative correlation between aerosol optical thickness (AOT) and cloud droplet effective radius (R{sub eff}) for all cases and satellite data, except for Exp N; a weak but negative correlation between liquid water path (LWP) and AOT for MODIS and CERES; and a robust increase in cloud cover with AOT for both MODIS and CERES. In all simulations, there is a positive correlation between AOT and both cloud cover and LWP (except in the case of LWP-AOT for Exp CN). The largest slopes are obtained for Exp N, implying that meteorological variability may be an important factor. The main fields associated with AOT variability in NCEP/MODIS data are warmer temperatures and increased subsidence for less clean cases, not well captured by the model. Simulated cloud fields compared with an enhanced data product from MODIS and AMSR-E indicate that model cloud thickness is over-predicted and cloud droplet number is within retrieval uncertainties. Since LWP fields are comparable this implies an under-prediction of R{sub eff} and thus an over-prediction of the indirect effect.

  15. Complementary information from TRMM and CloudSat to improve our global estimate of precipitation

    Science.gov (United States)

    Behrangi, A.; Stephens, G. L.; Adler, R. F.; Huffman, G. J.; Lambrigtsen, B.; Lebsock, M. D.

    2013-12-01

    Complementary information from CloudSat Cloud Profiling Radar (CPR), TRMM PR, and AMSR-E are used to investigate the precipitation detection and estimation performance of a suite of precipitation measuring sensors, commonly used in the production of the merged precipitation products. CPR has high sensitivity to liquid and frozen hydrometeors and can provide added information with respect to the measurement of light rain and snowfall within 80oS-80oN. PR has also enabled significant advancement in quantification of moderate to intense rainfall. The study requires careful consideration of the scale issues among different sensors that will be discussed. Furthermore, we expand the sensor-level analysis to investigate the performance of the global precipitation climatology products: GPCP and CMAP. CloudSat together with TRMM and AMSR-E are used to calculate the mean global precipitation rate and its zonal distribution through a merging process constrained by precipitation occurrence from CloudSat. The three sensors have not been used in GPCP and CMAP thus give us an independent estimate of global precipitation and can be used to understand and assess the strengths and potential weaknesses of the two products. The insights gained from the analysis are found extremely useful to guide our future updates of the products as well as to design future precipitation measuring sensors. The study highlights the important role of GPM to better detect and quantify global precipitation using its Ka/Ku band dual frequency precipitation radar (DPR) and multichannel passive microwave imager (GMI).

  16. On the formation and structure of rare-earth element complexes in aqueous solutions under hydrothermal conditions with new data on gadolinium aqua and chloro complexes

    Science.gov (United States)

    Mayanovic, Robert A.; Anderson, Alan J.; Bassett, William A.; Chou, I.-Ming

    2007-01-01

    Synchrotron X-ray spectroscopy experiments were made on the Gd(III) aqua and chloro complexes in low pH aqueous solutions at temperatures ranging from 25 to 500????C and at pressures up to 480??MPa using a hydrothermal diamond anvil cell. Analysis of fluorescence Gd L3-edge X-ray absorption fine structure (XAFS) spectra measured from a 0.006m Gd/0.16m HNO3 aqueous solution at temperatures up to 500????C and at pressures up to 260??MPa shows that the Gd-O distance of the Gd3+ aqua ion decreases steadily at a rate of ??? 0.007??A??/100????C whereas the number of coordinated H2O molecules decreases from 9.0 ?? 0.5 to 7.0 ?? 0.4. The loss of water molecules in the Gd3+ aqua ion inner hydration shell over this temperature range (a 22% reduction) is smaller than exhibited by the Yb3+ aqua ion (42% reduction) indicating that the former is significantly more stable than the later. We conjecture that the anomalous enrichment of Gd reported from measurement of REE concentrations in ocean waters may be attributed to the enhanced stability of the Gd3+ aqua ion relative to other REEs. Gd L3-edge XAFS measurements of 0.006m and 0.1m GdCl3 aqueous solutions at temperatures up to 500????C and pressures up to 480??MPa reveal that the onset of significant Gd3+-Cl- association occurs around 300????C. Partially-hydrated stepwise inner-sphere complexes most likely of the type Gd(H2O)??-nCln+3-n occur in the chloride solutions at higher temperatures, where ?? ??? 8 at 300????C decreasing slightly to an intermediate value between 7 and 8 upon approaching 500????C. This is the first direct evidence for the occurrence of partially-hydrated REE Gd (this study) and Yb [Mayanovic, R.A., Jayanetti, S., Anderson, A.J., Bassett, W.A., Chou, I-M., 2002a. The structure of Yb3+ aquo ion and chloro complexes in aqueous solutions at up to 500 ??C and 270 MPa. J. Phys. Chem. A 106, 6591-6599.] chloro complexes in hydrothermal solutions. The number of chlorides (n) of the partially-hydrated Gd

  17. Uncertainty and sensitivity analysis of the retrieved essential climate variables from remotely sensed observations

    Science.gov (United States)

    Djepa, Vera; Badii, Atta

    2016-04-01

    The sensitivity of weather and climate system to sea ice thickness (SIT), Sea Ice Draft (SID) and Snow Depth (SD) in the Arctic is recognized from various studies. Decrease in SIT will affect atmospheric circulation, temperature, precipitation and wind speed in the Arctic and beyond. Ice thermodynamics and dynamic properties depend strongly on sea Ice Density (ID) and SD. SIT, SID, ID and SD are sensitive to environmental changes in the Polar region and impact the climate system. For accurate forecast of climate change, sea ice mass balance, ocean circulation and sea- atmosphere interactions it is required to have long term records of SIT, SID, SD and ID with errors and uncertainty analyses. The SID, SIT, ID and freeboard (F) have been retrieved from Radar Altimeter (RA) (on board ENVISAT) and IceBridge Laser Altimeter (LA) and validated, using over 10 years -collocated observations of SID and SD in the Arctic, provided from the European Space Agency (ESA CCI sea ice ECV project). Improved algorithms to retrieve SIT from LA and RA have been derived, applying statistical analysis. The snow depth is obtained from AMSR-E/Aqua and NASA IceBridge Snow Depth radar. The sea ice properties of pancake ice have been retrieved from ENVISAT/Synthetic Aperture Radar (ASAR). The uncertainties of the retrieved climate variables have been analysed and the impact of snow depth and sea ice density on retrieved SIT has been estimated. The sensitivity analysis illustrates the impact of uncertainties of input climate variables (ID and SD) on accuracy of the retrieved output variables (SIT and SID). The developed methodology of uncertainty and sensitivity analysis is essential for assessment of the impact of environmental variables on climate change and better understanding of the relationship between input and output variables. The uncertainty analysis quantifies the uncertainties of the model results and the sensitivity analysis evaluates the contribution of each input variable to

  18. Effect of Terrestrial and Marine Organic Aerosol on Regional and Global Climate: Model Development, Application, and Verification with Satellite Data

    Energy Technology Data Exchange (ETDEWEB)

    Meskhidze, Nicholas; Zhang, Yang; Kamykowski, Daniel

    2012-03-28

    configuration of physics options in GWRF for global scale modeling in 2001 at a horizontal grid resolution of 1° x 1°. GU-WRF model output was evaluated using observational datasets from a variety of sources including surface based observations (NCDC and BSRN), model reanalysis (NCEP/ NCAR Reanalysis and CMAP), and remotely-sensed data (TRMM) to evaluate the ability of GU-WRF to simulate atmospheric variables at the surface as well as aloft. Explicit treatment of nanoparticles produced from new particle formation in GU-WRF/Chem-MADRID was achieved by expanding particle size sections from 8 to 12 to cover particles with the size range of 1.16 nm to 11.6m. Simulations with two different nucleation parameterizations were conducted for August 2002 over a global domain at a 4º by 5º horizontal resolution. The results are evaluated against field measurement data from the 2002 Aerosol Nucleation and Real Time Characterization Experiment (ANARChE) in Atlanta, Georgia, as well as satellite and reanalysis data. We have also explored the relationship between clean marine aerosol optical properties and ocean surface wind speed using remotely sensed data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on board the CALIPSO satellite and the Advanced Microwave Scanning Radiometer (AMSR-E) on board the AQUA satellite. Detailed data analyses were carried out over 15 regions selected to be representative of different areas of the global ocean for the time period from June 2006 to April 2011. We show that for very low (less than 4 m s-1) and very high (more than 12 m s-1) wind speed conditions the mean CALIPSO-derived aerosol optical depth (AOD) has little dependency on the surface wind speed. For an intermediate (between 4 and 12 m s-1) marine AOD was linearly correlated with the surface wind speed values, with a slope of 0.0062 s m-1. Results of our study suggest that considerable improvements to both optical properties of marine aerosols and their production mechanisms

  19. Hemoglobin levels and quality of life in patients with symptomatic chemotherapy-induced anemia: the eAQUA study

    Directory of Open Access Journals (Sweden)

    Mouysset JL

    2016-01-01

    Full Text Available Jean-Loup Mouysset,1 Beata Freier,2 Joan van den Bosch,3 Charles Briac Levaché,4 Alain Bols,5 Hans Werner Tessen,6 Laura Belton,7 G Chet Bohac,8 Jan-Henrik Terwey,9 Giuseppe Tonini101Department of Medical Oncology, Clinique Rambot Provencale, Aix en Provence, France; 2Clinical Oncology, Wojewodzki Szpital Specjalistyczny, Wroclaw, Poland; 3Department of Internal Medicine/Oncology, Albert Schweitzer Ziekenhuis locatie Dordwijk, Dordrecht, the Netherlands; 4Radiotherapy Service, Medical Oncology, Polyclinique Francheville, Périgueux, France; 5Central Pharmacy, AZ Sint-Jan Brugge-Oostende AV, Brugge, Belgium; 6Private Oncology Practice. Goslar, Germany; 7LB Biostatistics, London, UK; 8Clinical Research, Amgen Inc., Thousand Oaks, CA, USA; 9Medical Development – Oncology, Amgen (Europe GmbH, Zug, Switzerland; 10Department of Medical Oncology, Università Campus Bio-Medico, Roma, ItalyPurpose: To assess hemoglobin (Hb outcomes and fatigue-related quality-of-life (QoL (electronic assessment in patients with solid tumors and symptomatic chemotherapy-induced anemia receiving cytotoxic chemotherapy and darbepoetin alfa (DA or another erythropoiesis-stimulating agent according to European indication.Methods: eAQUA was a Phase IV prospective observational study. The primary outcome (assessed in the primary analysis set [PAS]: patients receiving one or more DA dose who had baseline and week 9 assessments for Hb and QoL was the proportion of patients receiving DA having both Hb increases ≥1 g/dL and improved QoL between baseline and week 9. Functional Assessment of Cancer Therapy-Fatigue (FACT-F subscale scores were anchored to fatigue visual analog scale scores to determine the minimally important difference for improved QoL. Overall data/data over time are reported for the full analysis set (patients receiving one or more erythropoiesis-stimulating agent dose, n=1,158; week 9 data (ie, data relating to the primary and secondary outcomes are reported

  20. Effect of rooting depth, plant density and planting date on maize (Zea Mays L.) yield and water use efficiency in semi-arid Zimbabwe: Modelling with AquaCrop

    NARCIS (Netherlands)

    Nyakudya, I.W.; Stroosnijder, L.

    2014-01-01

    Under low and poorly distributed rainfall higher food production can be achieved by increasing crop water use efficiency (WUE) through optimum soil fertility management and selection of deep-rooting cultivars, appropriate plant density and planting dates. We explored AquaCrop's applicability in sele

  1. In vivo effects of Aphanizomenon flos-aquae DC-1 aphantoxins on gas exchange and ion equilibrium in the zebrafish gill.

    Science.gov (United States)

    Zhang, Delu; Liu, Siyi; Zhang, Jing; Zhang, Jian Kong; Hu, Chunxiang; Liu, Yongding

    2016-08-01

    Aphantoxins, neurotoxins or paralytic shellfish poisons (PSPs) generated by Aphanizomenon flos-aquae, are a threat to environmental safety and human health in eutrophic waters worldwide. The molecular mechanisms of neurotoxin function have been studied; however, the effects of these neurotoxins on oxidative stress, ion transport, gas exchange, and branchial ultrastructure in fish gills are not fully understood. Aphantoxins extracted from A. flos-aquae DC-1 were detected by high-performance liquid chromatography. The major ingredients were gonyautoxins 1 and 5 and neosaxitoxin, which comprised 34.04%, 21.28%, and 12.77% of the total, respectively. Zebrafish (Danio rerio) were administered A. flos-aquae DC-1 aphantoxins at 5.3 or 7.61μg saxitoxin equivalents (eq)/kg (low and high doses, respectively) by intraperitoneal injection. The activities of Na(+)-K(+)-ATPase (NKA), carbonic anhydrase (CA), and lactate dehydrogenase (LDH), ultrastructural alterations in chloride and epithelial cells, and reactive oxygen species (ROS) and total antioxidative capacity (T-AOC) were investigated in the gills during the first 24h after exposure. Aphantoxins significantly increased the level of ROS and decreased the T-AOC in zebrafish gills from 3 to 12h post-exposure, suggesting an induction of oxidative stress and inhibition of antioxidant capacity. Reduced activities of NKA and CA demonstrated abnormal ion transport and gas exchange in the gills of aphantoxin-treated fish. Toxin administration also resulted in increased LDH activity and ultrastructural alterations in chloride and epithelial cells, suggesting a disruption of function and structure in zebrafish gills. The observed abnormalities in zebrafish gills occurred in a time- and dose-dependent manner. These findings demonstrate that aphantoxins or PSPs may inhibit ion transport and gas exchange, increase LDH activity, and result in ultrastructural damage to the gills through elevations in oxidative stress and reduced

  2. Morphological alterations and acetylcholinesterase and monoamine oxidase inhibition in liver of zebrafish exposed to Aphanizomenon flos-aquae DC-1 aphantoxins

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, De Lu, E-mail: deluzh@163.com [Department of Lifescience and Biotechnology, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Jing [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Hu, Chun Xiang, E-mail: cxhu@ihb.ac.cn [Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China); Wang, Gao Hong; Li, Dun Hai; Liu, Yong Ding [Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China)

    2014-12-15

    Highlights: • Aphantoxins induced zebrafish hepatic physiological and morphological changes. • AChE and MAO inhibition reflected abnormality of neurotransmitter inactivation. • ROS advance and T-AOC reduction suggested oxidative stress. • ALT, AST, histological and ultrastructural alterations indicated hepatic damage. - Abstract: Aphanizomenon flos-aquae is a cyanobacterium that produces neurotoxins or paralytic shellfish poisons (PSPs) called aphantoxins, which present threats to environmental safety and human health via eutrophication of water bodies worldwide. Although the molecular mechanisms of this neurotoxin have been studied, many questions remain unsolved, including those relating to in vivo hepatic neurotransmitter inactivation, physiological detoxification and histological and ultrastructural alterations. Aphantoxins extracted from the natural strain of A. flos-aquae DC-1 were analyzed by high-performance liquid chromatography. The main components were gonyautoxins 1 and 5 (GTX1, GTX5) and neosaxitoxin (neoSTX), which comprised 34.04%, 21.28%, and 12.77% respectively. Zebrafish (Danio rerio) were exposed intraperitoneally to 5.3 or 7.61 μg STX equivalents (eq)/kg (low and high doses, respectively) of A. flos-aquae DC-1 aphantoxins. Morphological alterations and changes in neurotransmitter conduction functions of acetylcholinesterase (AChE) and monoamine oxidase (MAO) in zebrafish liver were detected at different time points 1–24 h post-exposure. Aphantoxin significantly enhanced hepatic alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and histological and ultrastructural damage in zebrafish liver at 3–12 h post-exposure. Toxin exposure increased the reactive oxygen species content and reduced total antioxidative capacity in zebrafish liver, suggesting oxidative stress. AChE and MAO activities were significantly inhibited, suggesting neurotransmitter inactivation/conduction function abnormalities in zebrafish

  3. Spin-State Energetics of Fe(III) and Ru(III) Aqua Complexes: Accurate ab Initio Calculations and Evidence for Huge Solvation Effects.

    Science.gov (United States)

    Radoń, Mariusz; Gąssowska, Katarzyna; Szklarzewicz, Janusz; Broclawik, Ewa

    2016-04-12

    Aqua complexes of transition metals are useful models for understanding the electronic structure of metal-oxide species relevant in photocatalytic water splitting. Moreover, spin-forbidden d-d transitions of aqua complexes provide valuable experimental data of spin-state energetics, which can be used for benchmarking of computational methods. Here, low-energy spin states of Fe(III) and Ru(III) aqua complexes are studied with an array of DFT and high-level wave function methods (CASPT2, RASPT2, NEVPT2, CCSD(T)-F12, and other coupled cluster methods up to full CCSDT). The results from single-reference and multireference methods are cross-checked, and the amount of multireference character for both considered spin states of [Fe(H2O)6](3+) is carefully analyzed. In addition to small [M(H2O)6](3+) clusters (M = Fe, Ru), we also employ larger models [M(H2O)6·(H2O)12](3+), with explicit water molecules in the second coordination sphere, to describe the situation in aqueous solution. By comparing the results for both types of models, our calculations evidence large and systematic solvation effects on the spin-state energetics. It is found that, due to the interaction with hydrogen-bonded water molecules in the second coordination sphere, the first coordination sphere undergoes a noticeable contraction and deformation. In consequence, the presence of solvation shell affects the relative energies of spin states by as much as 3-4 × 10(3) cm(-1) (∼10 kcal/mol). Once this solvation effect is accounted for, the spin-state energetics from CCSD(T) and NEVPT2 calculations turn out to be in an excellent agreement with the experimental estimates, which was not the case for isolated [M(H2O)6](3+) species is gas phase. We thus postulate that significant discrepancies between theory and experimental data for [Fe(H2O)6](3+) that were previously reported in the literature may be plausibly resolved and attributed to the neglect of explicit solvation effects and also, to some extent, to

  4. A Review on Snow Data Sets%雪数据集研究综述

    Institute of Scientific and Technical Information of China (English)

    于灵雪; 张树文; 卜坤; 杨久春; 颜凤芹; 常丽萍

    2013-01-01

    The climate change is indicated by wide changes of snow cover.Through its distinctive physical properties,snow plays an important role in the global ecological system not only by regulating the material and energy cycle between land and atmosphere,but also by influencing surface runoff and the hydrologic cycle.After researching and comparing a lot of literatures,we summarized the frequently used data sets.The NOAA data sets which have the longest time series in visible/near infrared data sets are widely applied in monitoring snow cover over the continents and providing the input to the climate and hydrological numerical simulations.With better spatial resolution(1km or better),MODIS data sets which have great potential in the snow extraction can derive the snow cover through NDSI,a normalized index between band 4 and band 6.Microwave data sets are able to penetrate clouds and to detect the information about snow depth and snow water equivalent easily.Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I)data sets are the earliest microwave products for snow monitoring,while the coarse spatial resolution of which limits their application.AMSR-E data sets improve the resolution (25 krn) and are proven to be in good agreement with the measured values.To solve the problems existing in the single-source data sets,many researchers combine the advantages of different data sources and develop new algorithms to improve the accuracy and quality of the data sets.The synthesized data sets include the integrated datasets from model and observational data,the integration between observed data and remote sensing sensor,the combination between sensors and multi-source data sets.Among the above mentioned data sets,the combination between sensors,such as the combination between the MODIS and the AMSR-E,can enlarge the advantages (good spatial resolution of MODIS and anti-interference of AMSR-E) and overcome the shortcomings (MODIS is easily

  5. Drought monitoring using downscaled soil moisture through machine learning approaches over North and South Korea

    Science.gov (United States)

    Park, S.; Im, J.; Rhee, J.; Park, S.

    2015-12-01

    Soil moisture is one of the most important key variables for drought monitoring. It reflects hydrological and agricultural processes because soil moisture is a function of precipitation and energy flux and crop yield is highly related to soil moisture. Many satellites including Advanced Microwave Scanning Radiometer on the Earth Observing System (AMSR-E), Soil Moisture and Ocean Salinity sensor (SMOS), and Soil Moisture Active Passive (SMAP) provide global scale soil moisture products through microwave sensors. However, as the spatial resolution of soil moisture products is typically tens of kilometers, it is difficult to monitor drought using soil moisture at local or regional scale. In this study, AMSR-E and AMSR2 soil moisture were downscaled up to 1 km spatial resolution using Moderate Resolution Imaging Spectroradiometer (MODIS) data—Evapotranspiration, Land Surface Temperature, Leaf Area Index, Normalized Difference Vegetation Index, Enhanced Vegetation Index and Albedo—through machine learning approaches over Korean peninsula. To monitor drought from 2003 to 2014, each pixel of the downscaled soil moisture was scaled from 0 to 1 (1 is the wettest and 0 is the driest). The soil moisture based drought maps were validated using Standardized Precipitation Index (SPI) and crop yield data. Spatial distribution of drought status was also compared with other drought indices such as Scaled Drought Condition Index (SDCI). Machine learning approaches were performed well (R=0.905) for downscaling. Downscaled soil moisture was validated using in situ Asia flux data. The Root Mean Square Errors (RMSE) improved from 0.172 (25 km AMSR2) to 0.065 (downscaled soil moisture). The correlation coefficients improved from 0.201 (25 km AMSR2) to 0.341 (downscaled soil moisture). The soil moisture based drought maps and SDCI showed similar spatial distribution that caught both extreme drought and no drought. Since the proposed drought monitoring approach based on the downscaled

  6. Application and validation of AquaCrop model in simulating biomass and yield of oil flax in Northwest China%AquaCrop模型在西北胡麻生物量及产量模拟中的应用和验证

    Institute of Scientific and Technical Information of China (English)

    李玥; 牛俊义; 郭丽琢; 高珍妮; 孙小花

    2014-01-01

    为了预测水分和养分对胡麻籽粒产量、生物量与水分生产率的影响,使用FAO研发的水分驱动作物模型AquaCrop对胡麻在不同灌溉与氮磷水平下的生长情况进行模拟和验证.试验分别于2011年、2012年在甘肃省榆中县良种场进行,试验设置4个灌溉水平,3个氮水平,3个磷水平.模型性能的评价采用模型效率(E)、决定系数(R2)、均方根误差(RMSE)和平均绝对误差(MAE)等统计指标.分析结果表明:AquaCrop模型校正的籽粒产量和生物量在不同灌溉与氮磷水平处理下的预测误差统计值为:0.97<E<0.99,0.11 <RMSE<0.33,0.11 t·hm-2<MAE<0.42 t·hm-2,与2012年的试验观察数据(0.96<E<0.99,0.11 <RMSE<0.42,0.11 t·hm-2<MAE<0.39 t·hm-2)基本一致;同时,群体覆盖(CC)与生物量的模拟结果与测定值也非常拟合.AquaCrop模型在充分灌溉处理下预测胡麻产量,比非充分灌溉处理下具更高的准确性.因而,水分驱动模型AquaCrop在西北胡麻区不同的灌溉与田间管理措施下有较高的模拟精确性,具有广阔的应用前景和价值.

  7. Aqua{pentahydrogennitrilotris(methylenephosphonato)}lithium hydrate [Li(H2O){N(CH2PO3)3H5}] • H2O: Synthesis and structure

    Science.gov (United States)

    Somov, N. V.; Chausov, F. F.; Zakirova, R. M.

    2016-05-01

    Aqua{pentahydrogennitrilotris(methylenephosphonato)}lithium hydrate is a linear coordination polymer. Its crystal structure is described in space group P -1, Z = 2; a = 5.5732(2), b = 7.0106(2), and c = 16.9010(5) Å; α = 97.515(2)°, β = 94.551(2)°, and γ = 95.123(2)°. The tetrahedral coordination of the Li atom includes two oxygen atoms of a phosphonate ligand, one oxygen atom of another phosphonate ligand, and a water molecule. Complex formation is accompanied by closing of the eight-membered Li-O-P-C-N-C-P-O chelate ring. Polymeric chains run along the [100] direction. The chains are connected by hydrogen bonds.

  8. 心际迷航深圳东部华侨城瀑布酒店%HEART INTER-TREK——THE AQUA BOUTIQUE HOTEL IN SHENZHEN

    Institute of Scientific and Technical Information of China (English)

    杜宏涛

    2010-01-01

    @@ 位于深圳大梅沙的"东部华侨城",是以"让都市人回归自然"为宗旨,以文化旅游为特色的新型山地生态旅游度假区. ATENO天诺国际及其主创设计师孙建华设计的瀑布酒店(The Aqua Boutique Hotel)是华侨城主题酒店群中的一个,也是最令人期待的.酒店建筑藏身于宽300m、高70m的巨岩之中,外部更是有国内最高落差(42 m)的人造瀑布倾泻而下.

  9. Crystal structure of 4-(di-methyl-amino)-pyridinium cis-di-aqua-bis-(oxalato-κ(2) O,O')ferrate(III) hemihydrate.

    Science.gov (United States)

    Djomo, Edith Dimitri; Capet, Frédéric; Nenwa, Justin; Bélombé, Michel M; Foulon, Michel

    2015-08-01

    The Fe(III) ions in the hybrid title salt, (C7H11N2)[Fe(C2O4)2(H2O)2]·0.5H2O, show a distorted octa-hedral coordination environment, with four O atoms from two chelating oxalate dianions and two O atoms from two cis aqua ligands. The average Fe-O(oxalate) bond length [2.00 (2) Å] is shorter than the average Fe-O(water) bond length [2.027 (19) Å]. The ionic components are connected via inter-molecular N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network. PMID:26396759

  10. Influence of the nature of the oxidizing agents on the mechanism of the oxidation of carbon monoxide in the presence of an aqua complex of palladium (II)

    International Nuclear Information System (INIS)

    The kinetics of the oxidation of CO in the presence of an aqua complex of Pd(II) by VO+2 and Fe(III) ions and by heteropolyacids (HPA) viz., H3PMo12O40,H4PMo11 VO40, and H4PW11VO40, was studied. A comparison of the data obtained with the results of the oxidation of CO by strong oxidizing agents - Cr2O72- and Ce(IV) ions - made it possible to conclude that rapid occurrence of the reaction requires an optimum potential of the oxidizing agent 0.7 < E < 1 V. This confirms the assumption that the intermediate carbonyl complexes of partially reduced palladium are the most active in this reaction

  11. Crystal structure of poly[[di-μ2-aqua-aquasodium] 4-amino-3,5,6-trichloropyridine-2-carboxylate trihydrate], the sodium salt of the herbicide picloram

    OpenAIRE

    Graham Smith

    2015-01-01

    In the structure of the title complex, {[Na(H2O)3](C6H2Cl3N2O2)·3H2O}n, the sodium salt of the herbicide picloram, the cation adopts a polymeric chain structure, based on μ2-aqua-bridged NaO5 trigonal–bipyramidal complex units which have, in addition, a singly bonded water molecule. Each of the bridges within the chain, which extends parallel to the a axis, is centrosymmetric, with Na...Na separations of 3.4807 (16) and 3.5109 (16) Å. In the crystal, there are three water molecules of solvati...

  12. 3.2.1. Synthesis, crystal and molecular structure of catena-(bis(µ1-oxalic acid-µ3-hydrogen oxalate-di-aqua-sodium(I.

    Directory of Open Access Journals (Sweden)

    Olga Kovalchukova*, Sergey Aldoshin, Andrey Utenyshev, Konstantin Bogenko, Valeriy Tkachev

    2015-07-01

    Full Text Available The crystal and molecular structure of catena-(bis(µ- oxalic acid-µ-hydrogen oxalate-di-aqua-sodium(I was detected by X-Ray analysis. The compound crystallizes in the triclinic space group P-1, with a(Å 6.2378(12; b(Å 7,1115(14; c(Å 10.489(2; α(° 94.65(3; β(° 100.12(3; γ(° 97.78(3. The sodium cation in the title compound is eight coordinated and forms a square antiprism. It is surrounded by two molecules of oxalic acid, one hydrogen oxalate anion and one water molecule. Both oxalic acid and hydrogen oxalate anion act as polydentate bridging ligands. Centrosymmetric sodium cations are bounded by hydrogen oxalate anions through a system of H bonds involving the molecules of oxalic acid. In the lattice, the 3D structure stabilized by H bonds is formed.

  13. Purification and characterization of a corrinoid-compound in an edible cyanobacterium Aphanizomenon flos-aquae as a nutritional supplementary food.

    Science.gov (United States)

    Miyamoto, Emi; Tanioka, Yuri; Nakao, Tomoyuki; Barla, Florin; Inui, Hiroshi; Fujita, Tomoyuki; Watanabe, Fumio; Nakano, Yoshihisa

    2006-12-13

    The vitamin B12 concentration of the dried cells of Aphanizomenon flos-aquae was determined by both microbiological method with Lactobacillus delbrueckeii ATCC7830 and chemiluminescence method with intrinsic factor. The Aphanizomenon cells contained 616.3 +/- 30.3 micro g (n = 4) of vitamin B12 per 100 g of the dried cells by the microbiological method. The values determined with the chemiluminescence method, however, were only about 5.3% of the values determined by the microbiological method. A corrinoid-compound was purified from the dried cells and characterized. The purified corrinoid-compound was identified as pseudovitamin B12 (an inactive corrinoid-compound for humans) by silica gel 60 TLC, C18 reversed-phase HPLC, ultraviolet-visible spectroscopy, and 1H NMR spectroscopy. The results suggest that the Aphanizomenon cells are not suitable for use as a vitamin B12 source, especially in vegans.

  14. [Use of the AquaDuc T® round drinker with Pekin ducks under field conditions--behaviour as one indicator of welfare].

    Science.gov (United States)

    Rauch, Elke; Firnkäs, Nina; Hirsch, Nicola; Damme, Klaus; Schmidt, Paul; Erhard, Michael H; Bergmann, Shana

    2016-01-01

    Pekin ducks have an innate affinity for water. They seek water from the first day of life and use it for a multitude of behaviors. Currently implemented requirements to husbandry and the design of an animal-friendly offer of drinking water in commercial fattening establishments exist neither at EU-level nor in Germany. Aim of the study was to examine the use of the AquaDuc T® (Big Dutchman, Vechta, Germany) and its practical suitability concerning the behavior during the fattening of Pekin ducks under commercial conditions. The examinations took place in three farms (7140-13,515 fattening places). On farm 1 and 3, 16 fattening periods were observed (switch-over design: alternately test and control trial) with each one visited between day 28-32 and 35-39. On farm 2, only ten fattening periods could be examined. The ducks were in general supplied with drinking water via nipple drinkers. For the test trials, the AquaDuc T® drinkers were additionally installed and were accessible for a limited time. To record the natural and undisturbed behavior of the ducks in their housing system, the video recordings were started after we finished the farm visits and in total more than 6300 hours of video material were analyzed. All findings show that Pekin ducks clearly favor the round bell drinkers over the nipple drinkers. They enable the birds to immerse their heads, to drink and strain in a species-specific manner, to take care of the plumage with water and to clean beak and eyes. In the test trials, the drinking activity rose significantly during the operating time of the round drinkers (p water supply. For economic and hygienic reasons, the daily access to the modified round drinkers should be limited.

  15. [Use of the AquaDuc T® round drinker with Pekin ducks under field conditions--behaviour as one indicator of welfare].

    Science.gov (United States)

    Rauch, Elke; Firnkäs, Nina; Hirsch, Nicola; Damme, Klaus; Schmidt, Paul; Erhard, Michael H; Bergmann, Shana

    2016-01-01

    Pekin ducks have an innate affinity for water. They seek water from the first day of life and use it for a multitude of behaviors. Currently implemented requirements to husbandry and the design of an animal-friendly offer of drinking water in commercial fattening establishments exist neither at EU-level nor in Germany. Aim of the study was to examine the use of the AquaDuc T® (Big Dutchman, Vechta, Germany) and its practical suitability concerning the behavior during the fattening of Pekin ducks under commercial conditions. The examinations took place in three farms (7140-13,515 fattening places). On farm 1 and 3, 16 fattening periods were observed (switch-over design: alternately test and control trial) with each one visited between day 28-32 and 35-39. On farm 2, only ten fattening periods could be examined. The ducks were in general supplied with drinking water via nipple drinkers. For the test trials, the AquaDuc T® drinkers were additionally installed and were accessible for a limited time. To record the natural and undisturbed behavior of the ducks in their housing system, the video recordings were started after we finished the farm visits and in total more than 6300 hours of video material were analyzed. All findings show that Pekin ducks clearly favor the round bell drinkers over the nipple drinkers. They enable the birds to immerse their heads, to drink and strain in a species-specific manner, to take care of the plumage with water and to clean beak and eyes. In the test trials, the drinking activity rose significantly during the operating time of the round drinkers (p < 0.001), whereas the nipple drinkers were used less frequently at the same time. Concerning ethology and health, the round drinkers offer the ducks very good conditions for an animal-friendly water supply. For economic and hygienic reasons, the daily access to the modified round drinkers should be limited. PMID:26904894

  16. Radiometric calibration and performance trends of the Clouds and Earth's Radiant Energy System (CERES) instrument sensors onboard the Terra and Aqua spacecraft

    Science.gov (United States)

    Shankar, Mohan; Priestley, Kory; Smith, Nathaniel; Smith, Nitchie; Thomas, Susan; Walikainen, Dale

    2015-10-01

    The Clouds and Earth's Radiant Energy System (CERES) instruments help to study the impact of clouds on the earth's radiation budget. There are currently five instruments- two each on board Aqua and Terra spacecraft and one on the Suomi NPP spacecraft to measure the earth's reflected shortwave and emitted longwave energy, which represent two components of the earth's radiation energy budget. Flight Models (FM) 1 and 2 are on Terra, FM 3 and 4 are on Aqua, and FM5 is on Suomi NPP. The measurements are made by three sensors on each instrument: a shortwave sensor that measures the 0.3-5 microns wavelength band, a window sensor that measures the water vapor window between 8-12 microns, and a total sensor that measures all incident energy (0.3- >100 microns). The required accuracy of CERES measurements of 0.5% in the longwave and 1% in the shortwave is achieved through an extensive pre-launch ground calibration campaign as well as on-orbit calibration and validation activities. Onorbit calibration is carried out using the Internal Calibration Module (ICM) that consists of a tungsten lamp, blackbodies, and a solar diffuser known as the Mirror Attenuator Mosaic (MAM). The ICM calibration provides information about the stability of the sensors' broadband radiometric gains on-orbit. Several validation studies are conducted in order to monitor the behavior of the instruments in various spectral bands. The CERES Edition-4 data products for the FM1-FM4 instruments incorporate the latest calibration methodologies to improve on the Edition-3 data products. In this paper, we discuss the updated calibration methodology and present some validation studies to demonstrate the improvement in the trends using the CERES Edition-4 data products for all four instruments.

  17. Absolute Quantification of Prion Protein (90-231) Using Stable Isotope-Labeled Chymotryptic Peptide Standards in a LC-MRM AQUA Workflow

    Science.gov (United States)

    Sturm, Robert; Sheynkman, Gloria; Booth, Clarissa; Smith, Lloyd M.; Pedersen, Joel A.; Li, Lingjun

    2012-09-01

    Substantial evidence indicates that the disease-associated conformer of the prion protein (PrPTSE) constitutes the etiologic agent in prion diseases. These diseases affect multiple mammalian species. PrPTSE has the ability to convert the conformation of the normal prion protein (PrPC) into a β-sheet rich form resistant to proteinase K digestion. Common immunological techniques lack the sensitivity to detect PrPTSE at subfemtomole levels, whereas animal bioassays, cell culture, and in vitro conversion assays offer higher sensitivity but lack the high-throughput the immunological assays offer. Mass spectrometry is an attractive alternative to the above assays as it offers high-throughput, direct measurement of a protein's signature peptide, often with subfemtomole sensitivities. Although a liquid chromatography-multiple reaction monitoring (LC-MRM) method has been reported for PrPTSE, the chemical composition and lack of amino acid sequence conservation of the signature peptide may compromise its accuracy and make it difficult to apply to multiple species. Here, we demonstrate that an alternative protease (chymotrypsin) can produce signature peptides suitable for a LC-MRM absolute quantification (AQUA) experiment. The new method offers several advantages, including: (1) a chymotryptic signature peptide lacking chemically active residues (Cys, Met) that can confound assay accuracy; (2) low attomole limits of detection and quantitation (LOD and LOQ); and (3) a signature peptide retaining the same amino acid sequence across most mammals naturally susceptible to prion infection as well as important laboratory models. To the authors' knowledge, this is the first report on the use of a non-tryptic peptide in a LC-MRM AQUA workflow.

  18. 水华束丝藻对磷的生理响应研究%PHYSIOLOGICAL RESPONSE TO PHOSPHOURS IN APHANIZOMENON FLOS-AQUAE

    Institute of Scientific and Technical Information of China (English)

    施军琼; 吴忠兴; 马剑敏; 马帅

    2011-01-01

    factor at freshwater bodies, is always thought to be responsible to the bloom formation. However, there are relatively few data to study how to respond to the increase of phosphorus levels in Aphanizomenon at present. Therefore, in order to explain the responses to phosphorus in Aphanizomenon, the physiological and ecological functions of Aphanizomenon were selected to discuss in the present study. In this study, the physiological parameters, including the specific growth rate, photosynthesis evolution, maximum electron transfer rate (ETRmax) and alkaline phosphatase activities (APA), were investigated when Aphanizomenon flos-aquae, a type strain of Aphanizomenon, was cultured at different phosphorus concentrations (0.00, 0.02, 0.05, 0.50 and 1.00 mg/L). The results showed that significant decreases were found in the specific growth rate (|x), the maximum photosynthesis rate (pm), saturation light irradiance, PS II photochemical efficiency (Fv/Fm), and the maximum electron transfer rate (ETRmax), when A. Flos-aquae was inoculated into the Pi levels of less than 0.50 mg/L. On the contrary, significant increases were indicated in the respiration (Rd) of Aphanizomenon when cultured at lower Pi concentrations. It suggested that Pi stress was found in A. Flos-aquae when grown at less than 0.50 mg/L Pi concentration, and the stress might directly inhibit photosynthesis efficiency, which resulted in the increase of respiration and the decrease of growth. At the same time, A. Flos-aquae increased markedly its activity of alkaline phosphatase (APA) in order to response to the stress since alkaline phosphatase could translate organic phosphate into inorganic phosphate. When cultured at higher Pi concentration more than 0.50 mg/L, the physiological parameters did not markedly change, suggesting that A. Flos-aquae could keep a normal growth rate only when the Pi levels reached to 0.50 mg/L or higher. In conclusion, the data suggested that A. Flos-aquae could regulate its

  19. Study on the Simulation of the Canopy Growth of Spring Wheat in the Northeast Based on the AquaCrop Model%基于AquaCrop模型的东北春麦区小麦冠层生长模拟研究

    Institute of Scientific and Technical Information of China (English)

    李晶; 付驰; 张铁楠; 罗宁; 乔天长; 张丽芳; 魏湜

    2013-01-01

    AquaCrop作物模型数据库组建的基础上,应用该模型对东北春小麦冠层生长进行模拟.结果表明,除2010年呼玛地区模拟值低于实测值外,其余年份和地点的模拟值均高于实测值,IoA在0.726~0.995之间,模拟值与实测值的一致性较为理想;AquaCrop模型能较好反映正常年份下春麦生育活动,模型模拟情况与各地观测到的冠层发育情况较为一致.但对极端气候下的春麦冠层发育的模拟效果较为一般.在以后的研究中,需进一步对气象参数做出修正,以更好地应用于小麦的生产和预测.

  20. Inter-annual variability of aerosol optical depth over the tropical Atlantic Ocean based on MODIS-Aqua observations over the period 2002-2012

    Science.gov (United States)

    Gkikas, Antonis; Hatzianastassiou, Nikolaos

    2013-04-01

    The tropical Atlantic Ocean is affected by dust and biomass burning aerosol loads transported from the western parts of the Saharan desert and the sub-Sahel regions, respectively. The spatial and temporal patterns of this transport are determined by the aerosol emission rates, their deposition (wet and dry), by the latitudinal shift of the Intertropical Convergence Zone (ITCZ) and the prevailing wind fields. More specifically, in summer, Saharan dust aerosols are transported towards the Atlantic Ocean, even reaching the Gulf of Mexico, while in winter the Atlantic Ocean transport takes place in more southern latitudes, near the equator, sometimes reaching the northern parts of South America. In the later case, dust is mixed with biomass burning aerosols originating from agricultural activities in the sub-Sahel, associated with prevailing north-easterly airflow (Harmattan winds). Satellite observations are the appropriate tool for describing this African aerosol export, which is important to atmospheric, oceanic and climate processes, offering the advantage of complete spatial coverage. In the present study, we use satellite measurements of aerosol optical depth at 550nm (AOD550nm), on a daily and monthly basis, derived from MODIS-Aqua platform, at 1ox1o spatial resolution (Level 3), for the period 2002-2012. The primary objective is to determine the pixel-level and regional mean anomalies of AOD550nm over the entire study period. The regime of the anomalies of African export is interpreted in relation to the aerosol source areas, precipitation, wind patterns and temporal variability of the North Atlantic Oscillation Index (NAOI). In order to ensure availability of AOD over the Sahara desert, MODIS-Aqua Deep Blue products are also used. As for precipitation, Global Precipitation Climatology Project (GPCP) data at 2.5ox2.5o are used. The wind fields are taken from the National Center for Environmental Prediction (NCEP). Apart from the regime of African aerosol export

  1. Climatology and trends of aerosol optical depth over the Mediterranean basin during the last 12years (2002-2014) based on Collection 006 MODIS-Aqua data.

    Science.gov (United States)

    Floutsi, A A; Korras-Carraca, M B; Matsoukas, C; Hatzianastassiou, N; Biskos, G

    2016-05-01

    The Mediterranean basin is a region of particular interest for studying atmospheric aerosols due to the large variety of air masses it receives, and its sensitivity to climate change. In this study we use the newest collection (C006) of aerosol optical depth from MODIS-Aqua, from which we also derived the fine-mode fraction and Ångström exponent over the last 12years (i.e., from 2002 to 2014), providing the longest analyzed dataset for this region. The long-term regional optical depth average is 0.20±0.05, with the indicated uncertainty reflecting the inter-annual variability. Overall, the aerosol optical depth exhibits a south-to-north decreasing gradient and an average decreasing trend of 0.0030 per year (19% total decrease over the study period). The correlation between the reported AOD observations with measurements from the ground AERONET stations is high (R=0.76-0.80 depending on the wavelength), with the MODIS-Aqua data being slightly overestimated. Both fine-fraction and Ångström exponent data highlight the dominance of anthropogenic aerosols over the northern, and of desert aerosols over the southern part of the region. Clear intrusions of desert dust over the Eastern Mediterranean are observed principally in spring, and in some cases in winter. Dust intrusions dominate the Western Mediterranean in the summer (and sometimes in autumn), whereas anthropogenic aerosols dominate the sub-region of the Black Sea in all seasons but especially during summer. Fine-mode optical depth is found to decrease over almost all areas of the study region during the 12-year period, marking the decreasing contribution of anthropogenic particulate matter emissions over the study area. Coarse-mode aerosol load also exhibits an overall decreasing trend. However, its decrease is smaller than that of fine aerosols and not as uniformly distributed, underlining that the overall decrease in the region arises mainly from reduced anthropogenic emissions. PMID:26878641

  2. Synthesis, FT-IR characterization and crystal structure of aqua-(5,10,15,20-tetra-phenyl-porphyrinato-κ(4) N)manganese(III) tri-fluoro-methane-sulfonate.

    Science.gov (United States)

    Harhouri, Wafa; Mchiri, Chadlia; Najmudin, Shabir; Bonifácio, Cecilia; Nasri, Habib

    2016-05-01

    In the title salt, [Mn(C44H28N4)(H2O)](CF3SO3) or [Mn(III)(TPP)(H2O)](CF3SO3) (where TPP is the dianion of 5,10,15,20-tetra-phenyl-porphyrin), the Mn(III) cation is chelated by the four pyrrole N atoms of the porphyrinate anion and additionally coordinated by an aqua ligand in an apical site, completing the distorted square-pyramidal coordination environment. The average Mn-N(pyrrole) bond length is 1.998 (9) Å and the Mn-O(aqua) bond length is 2.1057 (15) Å. The central Mn(III) ion is displaced by 0.1575 (5) Å from the N4C20 mean plane of the porphyrinate anion towards the apical aqua ligand. The porphyrinate macrocycle exhibits a moderate ruffling and strong saddle deformations. In the crystal lattice, the [Mn(III)(TPP)(H2O)](+) cation and the tri-fluoro-methane-sulfonate counter-ions are arranged in alternating planes packed along [001]. The components are linked together through O-H⋯O hydrogen bonds and much weaker C-H⋯O and C-H⋯F inter-actions. The crystal packing is further stabilized by weak C-H⋯π inter-actions involving the pyrrole and phenyl rings of the porphyrin moieties. PMID:27308027

  3. 基于遗传算法综合Terra/Aqua MODIS热红外数据反演地表组分温度%Genetic algorithm based surface component temperatures retrieval by integrating MODIS TIR DATA from Terra and Aqua satellites

    Institute of Scientific and Technical Information of China (English)

    孙珂; 陈圣波

    2012-01-01

    混合像元组分温度相对来说更有应用价值,而多角度热红外遥感的发展推动了混合像元组分温度反演基础和方法的发展.根据前期数值模拟得到Terra和Aqua卫星上的MODIS测量可以认为是同一卫星在两个不同观测时间和观测角度上的测量,综合利用Terra和Aqua卫星上的MODIS数据反演混合像元内土壤和植被组分温度.根据混合像元热红外辐射模型,利用遗传算法,分别模拟Terra卫星MODIS的32和33通道,以及Terra和Aqua卫星上MODIS的32通道辐射反演了河北怀来试验区范围内植被覆盖率、土壤组分温度和比辐射率、植被组分温度和比辐射率等表面参数.通过与实测数据进行比较,综合利用上午Terra和下午Aqua卫星32通道数据反演的上午植被组分温度与地面同步测量温度偏差在1℃内,而利用上午Terra卫星32和33通道数据反演的上午植被组分温度与地面同步测量值偏差在1.4℃内.尽管利用双星数据反演的组分温度精度相对较高,但针对同一个像元,两个方案反演的结果有一定偏差.%The component temperatures are key parameters in the environment problems. The multi-angle thermal infrared data are important for the retrieval of component temperature. MODIS (Moderate Resolution Imaging Spectroradiom-eter) is one of the sensors onboard EOS-Terra and EOS-Aqua, two sun-synchronous polar orbiting satellites. The sensitivity analysis shows that the same MODIS bands of Terra and Aqua satellites measures in the same behavior under the same variations of atmospheric water vapor, solar and viewing geometries. These MODIS bands may be considered to be the observations of a satellite at two viewing angles and two viewing times. In the study, the foliage and soil component temperature were retrieved by integrating these MODIS data. Based on linear thermal infrared radiation model, the bands 32 and 33 in Terra-MODIS, or the band 32 in Tcrra-MODIS and Aqua

  4. Triethylammonium hexa-μ2-acetato-κ12O:O′-diacetato-κ2O-aqua-μ3-oxido-triferrate(III toluene monosolvate

    Directory of Open Access Journals (Sweden)

    Andrew R. Burgoyne

    2011-08-01

    Full Text Available The title compound, (C6H16N[Fe3(CH3CO28O(H2O]·C7H8, was serendipitously crystallized from a reaction of disilanol with iron(II acetate. The trinuclear acetatoferrate(III anion has a triethylammonium cation as the counterion. The three Fe atoms lie on the vertices of a regular triangle and are octahedrally coordinated. The complete coordination of the anion includes shared ligands among the three metal ions: a central tribridging O atom and six bidentate bridging acetyl groups. The six-coordinations of two of the metal ions are completed by a monodentate acetate ligand, whereas that of the third metal ion is completed by a water molecule. The uncoordinated triethylammonium cation is involved in N—H...O hydrogen bonding to a singly coordinated acetyl group. The coordinated aqua molecule is involved in bifurcated O—H...O hydrogen bonding. C—H...O interactions are also observed. The toluene solvent molecule is disordered over two sets of sites in a 0.609 (11:0.391 (11 ratio.

  5. Mycosporine-like Amino Acids and Other Phytochemicals Directly Detected by High-Resolution NMR on Klamath (Aphanizomenon flos-aquae) Blue-Green Algae.

    Science.gov (United States)

    Righi, Valeria; Parenti, Francesca; Schenetti, Luisa; Mucci, Adele

    2016-09-01

    This study describes for the first time the use of high-resolution nuclear magnetic resonance (NMR) on Klamath (Aphanizomenon flos-aquae, AFA) blue-green algae directly on powder suspension. These algae are considered to be a "superfood", due to their complete nutritional profile that has proved to have important therapeutic effects. The main advantage of NMR spectroscopy is that it permits the detection of a number of metabolites all at once. The Klamath alga metabolome was revealed to be quite complex, and the most peculiar phytochemicals that can be detected directly on algae by NMR are mycosporine-like amino acids (porphyra-334, P334; shinorine, Shi) and low molecular weight glycosides (glyceryl β-d-galactopyranoside, GalpG; glyceryl 6-amino-6-deoxy-α-d-glucopyranoside, ADG), all compounds with a high nutraceutical value. The presence of cis-3,4-DhLys was revealed for the first time. This molecule could be involved in the anticancer properties ascribed to AFA.

  6. Large Scale Variability of Mid-Tropospheric Carbon Dioxide as Observed by the Atmospheric Infrared Sounder (AIRS) on the NASA EOS Aqua Platform

    Science.gov (United States)

    Pagano, Thomas S.; Olsen, Edward T.

    2012-01-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral infrared instrument on the EOS Aqua Spacecraft, launched on May 4, 2002. AIRS has 2378 infrared channels ranging from 3.7 microns to 15.4 microns and a 13.5 km footprint. AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), produces temperature profiles with 1K/km accuracy, water vapor profiles (20%/2km), infrared cloud height and fraction, and trace gas amounts for CO2, CO, SO2, O3 and CH4 in the mid to upper troposphere. AIRS wide swath(cedilla) +/-49.5 deg , enables daily global daily coverage for over 95% of the Earth's surface. AIRS data are used for weather forecasting, validating climate model distribution and processes, and observing long-range transport of greenhouse gases. In this study, we examine the large scale and regional horizontal variability in the AIRS Mid-tropospheric Carbon Dioxide product as a function of season and associate the observed variability with known atmospheric transport processes, and sources and sinks of CO2.

  7. Phosphorus fractionation in sediment cores collected in 2005 before and after onset of an Aphanizomenon flos-aquae bloom in upper Klamath Lake, OR, USA

    Science.gov (United States)

    Simon, N.S.; Lynch, D.; Gallaher, T.N.

    2009-01-01

    We tested the hypothesis that there would be measurable losses of phosphorus (P) from surficial sediments of Upper Klamath Lake (UKL), Oregon, if sediments were a source of P during an algal bloom. We compared concentrations of total and forms of P at various depths in cores collected before and after the onset of a large Aphanizomenon flos-aquae bloom. Concentrations of inorganic P were determined in extraction solutions of MgCl2 (1 M, pH 8), citrate-dithionite-bicarbonate, and 1 M HCl. Sediments below 2 cm were dominated by residual P which is defined as total P minus inorganic P. During the study period, data from the top 2-cm of sediment indicated (a) significant decrease in total P concentration, primarily associated with iron oxyhydroxides at one site, and (b) significant increase in total P concentration associated with residual P at a second site. Data from two other sites indicated no net changes in concentrations of total P. ?? 2009 US Government.

  8. Land and Atmosphere Near-Real-Time Capability for Earth Observing System

    Science.gov (United States)

    Murphy, Kevin J.

    2011-01-01

    LANCE (Land, Atmosphere Near-Real-Time Capability for EOS) in 2009. LANCE consists of special processing elements, co-located with selected EOSDIS data centers and processing facilities. A primary goal of LANCE is to bring multiple near-real-time systems under one umbrella, offering commonality in data access, quality control, and latency. LANCE now processes and distributes data from the Moderate Resolution Imaging Spectroradiometer (MODIS), Atmospheric Infrared Sounder (AIRS), Advanced Microwave Scanning Radiometer Earth Observing System (AMSR-E), Microwave Limb Sounder (MLS) and Ozone Monitoring Instrument (OMI) instruments within 3 hours of satellite observation. The Rapid Response System and the Fire Information for Resource Management System (FIRMS) capabilities will be incorporated into LANCE in 2011. LANCE maintains a central website to facilitate easy access to data and user services. LANCE products are extensively tested and compared with science products before being made available to users. Each element also plans to implement redundant network, power and server infrastructure to ensure high availability of data and services. Through the user registration system, users are informed of any data outages and when new products or services will be available for access. Building on a significant investment by NASA in developing science algorithms and products, LANCE creates products that have a demonstrated utility for applications requiring near-real-time data. From lower level data products such as calibrated geolocated radiances to higher-level products such as sea ice extent, snow cover, and cloud cover, users have integrated LANCE data into forecast models and decision support systems. The table above shows the current near-real-time product categories by instrument. The ESDIS Project continues to improve the LANCE system and use the experience gained through practice to seek adjustments to improve the quality and performance of the system. For example, an

  9. Deriving the effect of wind speed on clean marine aerosol optical properties using the A-Train satellites

    Directory of Open Access Journals (Sweden)

    V. P. Kiliyanpilakkil

    2011-11-01

    Full Text Available The relationship between "clean marine" aerosol optical properties and ocean surface wind speed is explored using remotely sensed data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP on board the CALIPSO satellite and the Advanced Microwave Scanning Radiometer (AMSR-E on board the AQUA satellite. Detailed data analyses are carried out over 15 regions selected to be representative of different areas of the global ocean for the time period from June 2006 to April 2011. Based on remotely sensed optical properties the CALIPSO algorithm is capable of discriminating "clean marine" aerosols from other types often present over the ocean (such as urban/industrial pollution, desert dust and biomass burning. The global mean optical depth of "clean marine" aerosol at 532 nm (AOD532 is found to be 0.052 ± 0.038 (mean plus or minus standard deviation. The mean layer integrated particulate depolarization ratio of marine aerosols is 0.02 ± 0.016. Integrated attenuated backscatter and color ratio of marine aerosols at 532 nm were found to be 0.003 ± 0.002 sr−1 and 0.530 ± 0.149, respectively. A logistic regression between AOD532 and 10-m surface wind speed (U10 revealed three distinct regimes. For U10 ≤ 4 m s−1 the mean CALIPSO-derived AOD532 is found to be 0.02 ± 0.003 with little dependency on the surface wind speed. For 4 < U10 ≤ 12 m s−1, representing the dominant fraction of all available data, marine aerosol optical depth is linearly correlated with the surface wind speed values, with a slope of 0.006 s m−1. In this intermediate wind speed region, the AOD532 vs. U10 regression slope derived here is comparable to previously reported values. At very high wind speed values (U10 > 18 m s−1, the AOD532-wind speed relationship

  10. ASCAT soil moisture data assimilation through the Ensemble Kalman Filter for improving streamflow simulation in Mediterranean catchments

    Science.gov (United States)

    Loizu, Javier; Massari, Christian; Álvarez-Mozos, Jesús; Casalí, Javier; Goñi, Mikel

    2016-04-01

    Assimilation of Surface Soil Moisture (SSM) observations obtained from remote sensing techniques have been shown to improve streamflow prediction at different time scales of hydrological modeling. Different sensors and methods have been tested for their application in SSM estimation, especially in the microwave region of the electromagnetic spectrum. The available observation devices include passive microwave sensors such as the Advanced Microwave Scanning Radiometer - Earth Observation System (AMSR-E) onboard the Aqua satellite and the Soil Moisture and Ocean Salinity (SMOS) mission. On the other hand, active microwave systems include Scatterometers (SCAT) onboard the European Remote Sensing satellites (ERS-1/2) and the Advanced Scatterometer (ASCAT) onboard MetOp-A satellite. Data assimilation (DA) include different techniques that have been applied in hydrology and other fields for decades. These techniques include, among others, Kalman Filtering (KF), Variational Assimilation or Particle Filtering. From the initial KF method, different techniques were developed to suit its application to different systems. The Ensemble Kalman Filter (EnKF), extensively applied in hydrological modeling improvement, shows its capability to deal with nonlinear model dynamics without linearizing model equations, as its main advantage. The objective of this study was to investigate whether data assimilation of SSM ASCAT observations, through the EnKF method, could improve streamflow simulation of mediterranean catchments with TOPLATS hydrological complex model. The DA technique was programmed in FORTRAN, and applied to hourly simulations of TOPLATS catchment model. TOPLATS (TOPMODEL-based Land-Atmosphere Transfer Scheme) was applied on its lumped version for two mediterranean catchments of similar size, located in northern Spain (Arga, 741 km2) and central Italy (Nestore, 720 km2). The model performs a separated computation of energy and water balances. In those balances, the soil

  11. Modelling climate change impacts on and adaptation strategies for agriculture in Sardinia and Tunisia using AquaCrop and value-at-risk.

    Science.gov (United States)

    Bird, David Neil; Benabdallah, Sihem; Gouda, Nadine; Hummel, Franz; Koeberl, Judith; La Jeunesse, Isabelle; Meyer, Swen; Prettenthaler, Franz; Soddu, Antonino; Woess-Gallasch, Susanne

    2016-02-01

    In Europe, there is concern that climate change will cause significant impacts around the Mediterranean. The goals of this study are to quantify the economic risk to crop production, to demonstrate the variability of yield by soil texture and climate model and to investigate possible adaptation strategies. In the Rio Mannu di San Sperate watershed, located in Sardinia (Italy) we investigate production of wheat, a rainfed crop. In the Chiba watershed located in Cap Bon (Tunisia), we analyze irrigated tomato production. We find, using the FAO model AquaCrop that crop production will decrease significantly in a future climate (2040-2070) as compared to the present without adaptation measures. Using "value-at-risk", we show that production should be viewed in a statistical manner. Wheat yields in Sardinia are modelled to decrease by 64% on clay loams, and to increase by 8% and 26% respectively on sandy loams and sandy clay loams. Assuming constant irrigation, tomatoes sown in August in Cap Bon are modelled to have a 45% chance of crop failure on loamy sands; a 39% decrease in yields on sandy clay loams; and a 12% increase in yields on sandy loams. For tomatoes sown in March; sandy clay loams will fail 81% of the time; on loamy sands the crop yields will be 63% less while on sandy loams, the yield will increase by 12%. However, if one assume 10% less water available for irrigation then tomatoes sown in March are not viable. Some adaptation strategies will be able to counteract the modelled crop losses. Increasing the amount of irrigation one strategy however this may not be sustainable. Changes in agricultural management such as changing the planting date of wheat to coincide with changing rainfall patterns in Sardinia or mulching of tomatoes in Tunisia can be effective at reducing crop losses.

  12. The AQUA-FONTIS study: protocol of a multidisciplinary, cross-sectional and prospective longitudinal study for developing standardized diagnostics and classification of non-thyroidal illness syndrome

    Directory of Open Access Journals (Sweden)

    Klein Harald H

    2008-10-01

    Full Text Available Abstract Background Non-thyroidal illness syndrome (NTIS is a characteristic functional constellation of thyrotropic feedback control that frequently occurs in critically ill patients. Although this condition is associated with significantly increased morbidity and mortality, there is still controversy on whether NTIS is caused by artefacts, is a form of beneficial adaptation, or is a disorder requiring treatment. Trials investigating substitution therapy of NTIS revealed contradictory results. The comparison of heterogeneous patient cohorts may be the cause for those inconsistencies. Objectives Primary objective of this study is the identification and differentiation of different functional states of thyrotropic feedback control in order to define relevant evaluation criteria for the prognosis of affected patients. Furthermore, we intend to assess the significance of an innovative physiological index approach (SPINA in differential diagnosis between NTIS and latent (so-called "sub-clinical" thyrotoxicosis. Secondary objective is observation of variables that quantify distinct components of NTIS in the context of independent predictors of evolution, survival or pathophysiological condition and influencing or disturbing factors like medication. Design The approach to a quantitative follow-up of non-thyroidal illness syndrome (AQUA FONTIS study is designed as both a cross-sectional and prospective longitudinal observation trial in critically ill patients. Patients are observed in at least two evaluation points with consecutive assessments of thyroid status, physiological and clinical data in additional weekly observations up to discharge. A second part of the study investigates the neuropsychological impact of NTIS and medium-term outcomes. The study design incorporates a two-module structure that covers a reduced protocol in form of an observation trial before patients give informed consent. Additional investigations are performed if and after

  13. Retrieval of tropospheric CO column from hyperspectral infrared sounders – application to four years of Aqua/AIRS and MetOp-A/IASI

    Directory of Open Access Journals (Sweden)

    L. Crépeau

    2012-05-01

    Full Text Available Four years of tropospheric integrated content of CO are retrieved from infrared hyperspectral observations of AIRS onboard Aqua and IASI onboard MetOp-A, for the period July 2007–June 2011. The retrieval method is based on a double differential approach that relies on the difference between brightness temperatures (BT observed by the sounder and BT simulated by the 4A radiative transfer model on collocated ECMWF reanalyses, for several couples of channels located in the 4.7 μm CO band. AIRS and IASI give access to similar integrated contents of CO with a maximum sensitivity near 450 hPa and half a maximum between 200 and 750 hPa depending on the thermal contrast (i.e. the difference between the surface temperature and the temperature of the first pressure level. However, differences in their spectral and radiometric characteristics yield differences in the retrieval characteristics with AIRS selected couples of channels being more sensitive to surface characteristics. Moreover, IASI covers the whole CO absorption band, with a 3 times greater spectral resolution, giving access to channels presenting a 3 times higher signal to noise ratio. This results in a better precision and lower standard deviation of the IASI retrievals. Conservatively, comparisons with CARIBIC aircraft measurements yield a relative difference of 3.42% for IASI and 4.92% for AIRS. On average, AIRS and IASI retrievals are in very good agreement, showing the same seasonality, seasonal amplitudes, interannual variability and spatial distribution. The analysis of the monthly evolution of CO particularly highlights the strong influence of biomass burning on the evolution of CO in several tropical regions. In particular, a sharp increase in CO in 2010 in the southern tropics, especially over South America and South Africa, is observed, and is shown to be related to El Niño and to the Atlantic Multidecadal Oscillation.

  14. Retrieval of tropospheric CO column from hyperspectral infrared sounders – application to four years of Aqua/AIRS and MetOp-A/IASI

    Directory of Open Access Journals (Sweden)

    L. Crépeau

    2012-10-01

    Full Text Available Four years of tropospheric integrated content of CO were retrieved from infrared hyperspectral observations of AIRS onboard Aqua and IASI onboard MetOp-A, for the period July 2007–June 2011. The retrieval method is based on a double differential approach that relies on the difference between brightness temperatures observed by the sounder and BT simulated by the Automatised Atmospheric Absorption Atlas (4A radiative transfer model on colocated ECMWF reanalyses, for several couples of channels located in the 4.67 μm CO band. AIRS and IASI give access to similar integrated contents of CO with a maximum sensitivity near 450 hPa and a half-height width of the weighting function between 200 and 750 hPa depending on the thermal contrast (i.e., the difference between the surface temperature and the temperature of the first pressure level. However, differences in their spectral and radiometric characteristics yield differences in the retrieval characteristics with AIRS selected couples of channels being more sensitive to surface characteristics. Moreover, IASI covers the whole CO absorption band, with a 3 times better spectral resolution, giving access to channels presenting a 3 times higher signal to noise ratio. This results in a better precision and lower standard deviation of the IASI retrievals. Conservatively, comparisons with CARIBIC aircraft measurements yield an averaged relative difference of 3.4% for IASI and 4.9% for AIRS. On average, AIRS and IASI retrievals are in very good agreement, showing the same seasonality, seasonal amplitudes, interannual variability and spatial distribution. The analysis of the monthly evolution of CO particularly highlights the expected strong influence of biomass burning on the evolution of CO in several tropical regions. In particular, a sharp increase in CO in 2010 in the southern tropics, especially over South America and South Africa, is observed, and is shown to be related to El Niño and to the Atlantic

  15. AIRS Pixel Cloud Detection Based on MODIS Cloud Products on Aqua Satellite%EOS卫星上基于MODIS云产品的AIRS像素云检测

    Institute of Scientific and Technical Information of China (English)

    王丹凤; 张记龙; 王志斌; 陈媛媛; 陈友华

    2012-01-01

    联合使用搭载在地球观测系统(EOS) Aqua卫星上的中分辨力成像光谱仪MODIS和大气红外探测器AIRS,能够提高对全球云量分布情况的检测.利用几何扫描特性的空间匹配算法,MODIS云分类掩膜和云相态掩膜产品,结合业务上的云检测算法,实现了用空间匹配的MODIS数据对AIRS像素云特性的检测.结果表明,用MODIS 1 km分辨力产品可以鉴别出AIRS像素中不同的云类型、云层信息(低云、中云或者高云)和云相态信息(水云、冰云或者混合相态信息).%The combined systems of the Moderate Resolution Imaging Spectroradiometer(MODIS) and the Atmospheric Infrared Sounder (AIRS) measurements from the Earth Observing System's (EOS's) Aqua satellite enable improve global monitoring of the distribution of clouds. Using the space collocation algorithms based on the scanning geometry, MODIS cloud phase mask, MODIS classification mask, also combing with the operational algorithm of MODIS cloud retrieval, the function of testing AIRS Subpixel Cloud Characterization based on space collocationed of MODIS data is realized. The results show that MODIS 1 km-spatial-resolution data is applied to identify various cloud types. Cloud-layer information(lower, midlevel, or high clouds) and phase information (water,ice,or mixed-phase clouds)within an AIRS footprint.

  16. Modelling climate change impacts on and adaptation strategies for agriculture in Sardinia and Tunisia using AquaCrop and value-at-risk.

    Science.gov (United States)

    Bird, David Neil; Benabdallah, Sihem; Gouda, Nadine; Hummel, Franz; Koeberl, Judith; La Jeunesse, Isabelle; Meyer, Swen; Prettenthaler, Franz; Soddu, Antonino; Woess-Gallasch, Susanne

    2016-02-01

    In Europe, there is concern that climate change will cause significant impacts around the Mediterranean. The goals of this study are to quantify the economic risk to crop production, to demonstrate the variability of yield by soil texture and climate model and to investigate possible adaptation strategies. In the Rio Mannu di San Sperate watershed, located in Sardinia (Italy) we investigate production of wheat, a rainfed crop. In the Chiba watershed located in Cap Bon (Tunisia), we analyze irrigated tomato production. We find, using the FAO model AquaCrop that crop production will decrease significantly in a future climate (2040-2070) as compared to the present without adaptation measures. Using "value-at-risk", we show that production should be viewed in a statistical manner. Wheat yields in Sardinia are modelled to decrease by 64% on clay loams, and to increase by 8% and 26% respectively on sandy loams and sandy clay loams. Assuming constant irrigation, tomatoes sown in August in Cap Bon are modelled to have a 45% chance of crop failure on loamy sands; a 39% decrease in yields on sandy clay loams; and a 12% increase in yields on sandy loams. For tomatoes sown in March; sandy clay loams will fail 81% of the time; on loamy sands the crop yields will be 63% less while on sandy loams, the yield will increase by 12%. However, if one assume 10% less water available for irrigation then tomatoes sown in March are not viable. Some adaptation strategies will be able to counteract the modelled crop losses. Increasing the amount of irrigation one strategy however this may not be sustainable. Changes in agricultural management such as changing the planting date of wheat to coincide with changing rainfall patterns in Sardinia or mulching of tomatoes in Tunisia can be effective at reducing crop losses. PMID:26187862

  17. Application of AquaCrop model for yield and irrigation requirement estimation of sugar beet under climate change conditions in Serbia

    Directory of Open Access Journals (Sweden)

    Stričević Ružica J.

    2014-01-01

    Full Text Available Climate change impact on field production may play a great role in strategic planning on soil and water resources management. Therefore, the aim of this work was to find out the impact of climate change on sugar beet yield, irrigation depth variation and water saving practices. AquaCrop model v.4.0 was used for yield and irrigation requirement estimation. Input data for future climatic parameters were obtained from EBU-POM for four scenarios A1B, A2, A1B* and A* (*>CO2, and periods of observation were first (2010-2039; second (2040-2069, and third (2070-2099. Undoubtedly, yield will not be reduced in the first period by any scenario, on the contrary, it might be increased. In the second period, yield reduction was observed in A1B and A2 scenarios, hence without the increment of CO2 in the Vojvodina region, whereas in Central Serbia, yield reduction might be expected even in scenarios of A1B and A2*. Irrigation could ensure yield increment in both regions, provided that an increase is more considerable in Central Serbia, due to lower soil water capacity. Application of optimal irrigation depth yield could be increased by up to 57-97% in Vojvodina and 77-285% in Central Serbia. Lower values are obtained in the first period and the highest in the third period. Applying deficit irrigation, water saving would reduce yield in scenario A2, otherwise to obtain high yield, irrigation depth of 300-500 mm should be ensured in Central Serbia. In the same scenario, 300-420 mm of water for irrigation is needed in Vojvodina, but its water savings could be 80-120 mm, or 20%. In scenario A1B, to obtain high yield, 80 mm could be saved in both regions. [Projekat Ministarstva nauke Republike Srbije, br. TR 37005

  18. Quantitative analysis of yield and soil water balance for summer maize on the piedmont of the North China Plain using AquaCrop

    Directory of Open Access Journals (Sweden)

    Jingjing WANG,Feng HUANG,Baoguo LI

    2015-12-01

    Full Text Available The North China Plain (NCP is a major grain production area in China, but the current winter wheat-summer maize system has resulted in a large water deficit. This water-shortage necessitates the improvement of crop water productivity in the NCP. A crop water model, AquaCrop, was adopted to investigate yield and water productivity (WP for rain-fed summer maize on the piedmont of the NCP. The data sets to calibrate and validate the model were obtained from a 3-year (2011—2013 field experiment conducted on the Yanshan piedmont of the NCP. The range of root mean square error (RMSE between the simulated and measured biomass was 0.67—1.25 t·hm-2, and that of relative error (RE was 9.4%—15.4%, the coefficient of determination (R2 ranged from 0.992 to 0.994. The RMSE between the simulated and measured soil water storage at depth of 0—100 cm ranged from 4.09 to 4.39 mm; and RE and R2 in the range of 1.07%—1.20% and 0.880—0.997, respectively. The WP as measured by crop yield per unit evapotranspiration was 2.50—2.66 kg·m-3. The simulated impact of long-term climate (i.e., 1980—2010 and groundwater depth on crop yield and WP revealed that the higher yield and WP could be obtained in dry years in areas with capillary recharge from groundwater, and much lower values elsewhere. The simulation also suggested that supplementary irrigation in areas without capillary groundwater would not result in groundwater over-tapping since the precipitation can meet the water required by both maize and ecosystem, thus a beneficial outcome for both food and ecosystem security can be assured.

  19. Long-term trend of aerosol optical depth derived from MODIS Aqua using linear regression and ensemble empirical mode decomposition over East Asia

    Science.gov (United States)

    KIM, J.

    2015-12-01

    Aerosol has played an important role in air quality for short term and climate change for long term. Especially, it is important to understand how aerosol optical depth (AOD) has changed to date for the prognosis of future atmospheric state and radiation budget which are related to human life. In this study, the trend of AOD at 550 nm from MODIS Aqua (MYD08) was estimated for 10 years from 2004 to 2014 using linear regression method and ensemble empirical mode decomposition method (EEMD). Search region was selected to East Asia [18.5°N-51.5°N, 85.5°E-150.5°E] which is considered to be of great interest in emission source. The result of linear regression shows remarkably increasing trend in North and East China including Sanjiang, Hailun, Beijing, Beijing forest and Jinozhou Bay, than rather downward trend in other neighboring regions. Actually, however, AOD has seasonality itself and its trend is also affected by external source consistently, so non-linear trend analysis was conducted to analyze the changing tendency of AOD trends. Consequently, secular trends of AOD defined by EEMD showed almost similar values over the entire region, but their shapes over time are quite different with those of linear regression. Here, AOD linear trend in Beijing has monotonically increased [0.03% yr-1] since 2004, but its non-linear trend shows that initial increasing trend has alleviated and even turned into downward trend from about 2010. Lastly, the validation of MODIS AOD with AErosol RObotic NETwork (AERONET) was conducted additionally which showed fairly good agreement with those of AERONET (R=0.901, RMSE=0.226, MAE=0.031, MBE=-0.001).

  20. Hydride generation atomic fluorescence spectrometric determination of As, Bi, Sb, Se(IV) and Te(IV) in aqua regia extracts from atmospheric particulate matter using multivariate optimization

    Energy Technology Data Exchange (ETDEWEB)

    Moscoso-Perez, Carmen [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain); Moreda-Pineiro, Jorge [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain)]. E-mail: jmoreda@udc.es; Lopez-Mahia, Purificacion [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain); Muniategui-Lorenzo, Soledad [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain); Fernandez-Fernandez, Esther [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain); Prada-Rodriguez, Dario [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071 A Coruna (Spain)

    2004-11-22

    A highly sensitive and simple method, based on hydride generation and atomic fluorescence detection, has been developed for the determination of As, Bi, Sb, Se(IV) and Te(IV) in aqua regia extracts from atmospheric particulate matter samples. Atmospheric particulates matter was collected on glass fiber filters using a medium volume sampler (PM1 particulate matter). Two-level factorial designs have been used to optimise the hydride generation atomic fluorescence spectrometry (HG-AFS) procedure. The effects of several parameters affecting the hydride generation efficiency (hydrochloric acid, sodium tetrahydroborate and potassium iodide concentrations and flow rates) have been evaluated using a Plackett-Burman experimental design. In addition, parameters affecting the hydride measurement (delay, analysis and memory times) have been also investigated. The significant parameters obtained (sodium tetrahydroborate concentration, sodium tetrahydroborate flow rate and analysis time for As; hydrochloric acid concentration and sodium tetrahydroborate flow rate for Se(IV); and sodium tetrahydroborate concentration and sodium tetrahydroborate flow rate for Te(IV)) have been optimized by using 2{sup n} + star central composite design. Hydrochloric acid concentration and sodium tetrahydroborate flow rate were the significant parameters obtained for Sb and Bi determination, respectively. Using a univariate approach these parameters were optimized. The accuracy of methods have been verified by using several certified reference materials: SRM 1648 (urban particulate matter) and SRM 1649a (urban dust). Detection limits in the range of 6 x 10{sup -3} to 0.2 ng m{sup -3} have been achieved. The developed methods were applied to several atmospheric particulate matter samples corresponding to A Coruna city (NW Spain)

  1. Detection of frequently-burn locations using multi-temporal Terra/Aqua MODIS fire product (MOD14) in Oudomxay province, Laos

    International Nuclear Information System (INIS)

    Wildfire is natural and man-made disaster that relates to global warming and climate change. Wildfire is prominent disaster that destroys natural resources, and causes enormous danger to human life and property. The study on the spatial and temporal distribution of wildfire is significant to understand wildfire occurrence and behavior. In the past, people usually study on the pattern of wildfire and open-space burning according to the daily number of active fire detected by MODIS sensor onboard of Terra and Aqua satellites for a particular area at the time of satellite over pass. However, there is no study that focused on the active fire that frequently occurred at the same location for a given period of time. Therefore, in this paper, the authors has focused on the study of frequently-burn locations in Oudomxay province of Laos, which has the 3rd highest active fire number in burning season of year 2007-2009 using spatial and statistical analysis of the active fire distribution and occurrence by time and space. The results of the study show that the highest number of burning frequency is 6 and 7 times within the study period and these numbers are located at 3 districts. One is Xai district which has the highest frequently-burn location for 7 times during the study period at the coordinate of N20.72° and E101.88°. The second districts are Beng and Nga districts which has the 2nd highest frequently-burn location for 6 times during the study period at the coordinate of N 20.28°, E101.68°, and N20.17°, E102.02°, respectively. The obtained information on frequently-burn locations in the province would be useful to identify the repeat burning activity by the local people occurred in the same location and allows the forestry and agricultural officers understand the wildfire distribution pattern

  2. Spatially and Temporally Complete Satellite Soil Moisture Data Based on a Data Assimilation Method

    Directory of Open Access Journals (Sweden)

    Zhiqiang Xiao

    2016-01-01

    Full Text Available Multiple soil moisture products have been generated from data acquired by satellite. However, these satellite soil moisture products are not spatially or temporally complete, primarily due to track changes, radio-frequency interference, dense vegetation, and frozen soil. These deficiencies limit the application of soil moisture in land surface process simulation, climatic modeling, and global change research. To fill the gaps and generate spatially and temporally complete soil moisture data, a data assimilation algorithm is proposed in this study. A soil moisture model is used to simulate soil moisture over time, and the shuffled complex evolution optimization method, developed at the University of Arizona, is used to estimate the control variables of the soil moisture model from good-quality satellite soil moisture data covering one year, so that the temporal behavior of the modeled soil moisture reaches the best agreement with the good-quality satellite soil moisture data. Soil moisture time series were then reconstructed by the soil moisture model according to the optimal values of the control variables. To analyze its performance, the data assimilation algorithm was applied to a daily soil moisture product derived from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E, the Microwave Radiometer Imager (MWRI, and the Advanced Microwave Scanning Radiometer 2 (AMSR2. Preliminary analysis using soil moisture data simulated by the Global Land Data Assimilation System (GLDAS Noah model and soil moisture measurements at a multi-scale Soil Moisture and Temperature Monitoring Network on the central Tibetan Plateau (CTP-SMTMN was performed to validate this method. The results show that the data assimilation algorithm can efficiently reconstruct spatially and temporally complete soil moisture time series. The reconstructed soil moisture data are consistent with the spatial precipitation distribution and have strong

  3. Evaluation of vinasse/aqua ammonia mixture applied to soil fertilization in sugar cane areas harvested lacking sugar cane trash without prior burning: losses of NH3 by volatilization and 15 N recovery

    International Nuclear Information System (INIS)

    The present work aimed to evaluate the losses of NH3 by volatization, from the vinasse/aqua ammonia mixture and urea solution applied to the soil. The N dose applied for both sources was 80 Kg ha-1, with the volume of vinasse and urea solution applied to the surface being 200 and 100 m3, respectively. The nitrogen sources were applied to soil covered or not by sugarcane trash. A semi-opened static collector device was used to evaluate the ammonia volatization. The isotopic technique with 15 N was used to quantify the N recovered in the soil from the nitrogen sources applied in microplots. These microplots consisted of 96 mm-diameter PVC cylinders which were buried in the soil at 200 mm. The results show that the volatization of ammonia from the vinasse/aqua ammonia mixture, applied to the soil covered or not by sugarcane trash, ranged from 5 to 7% of the N applied. These results were similar to those observed in the treatment where urea solution was applied to the soil lacking sugarcane trash, but lower when compared to the urea applied to the soil covered with trash confirmed the volatization results, with the least 15 N recovery (57%) being obtained in this treatment. In the other treatments, i.e. urea applied to soil lacking sugarcane trash; aqua annonia/vinasse mixture applied to soil covered or not with sugarcane trash, the mean recovery of 15 N were 60.2; 70.6 and 74.2 % respectively. These results support the recommendation of the use of a fluid mixture for nitrogen fertilization in ratoon cane areas after the mechanized sugarcane harvest without prior burning. (author). 15 refs., 1 fig., 1 tab

  4. Winter wheat leaf area index retrieval with multi-angle and multi-spectral Terra/Aqua MODIS data%联合Terra/Aqua MODIS多角度多光谱数据反演冬小麦叶面积指数

    Institute of Scientific and Technical Information of China (English)

    何维; 杨华

    2013-01-01

      Terra 与 Aqua 双星搭载的 MODIS 传感器可实现每日上下午分别对同一地点观测一次,并且由于卫星轨道漂移形成累积连续多天的多角度观测特点,加上多通道的光谱响应,极大地丰富了地表目标的观测信息,为 LAI等地表参数的实时准确反演提供了可能。该文利用 MODIS 双星高质量的连续多天的多波段地表反射率数据,结合 PROSAIL(PROSPECT+SAIL,properties spectra + scattering by arbitrarily inclined leaves)模型和查找表方法反演冬小麦 LAI,并与 MODIS LAI 产品及野外采样点实测 LAI 对比,结果表明,联合双星高质量的多角度多波段数据能够较准确反演冬小麦 LAI,其反演结果无论从空间分布还是时序变化特征来讲,较 MODIS LAI 产品更符合实际情况,也更接近地面实测值。该文的研究为充分利用 MODIS 数据的角度和光谱信息反演小麦等农作物的 LAI提供了一定的借鉴。%MODIS sensors, carried onboard Terra and Aqua satellites, scan the same location daily at a fixed time. Because of the sequential multidirectional information contributed by satellite orbit drift along with multi-channel spectral responses, MODIS data greatly enriches the observations of land surface targets, which makes it possible to estimate the land surface parameters accurately and timely, such as leaf area index (LAI). Many researchers have focused on LAI estimation using MODIS data, among whom most used the multispectral data of a single satellite in one day or eight days, while few comprehensively utilized the multispectral and multidirectional information obtained by the both MODIS sensors in some sequence of days. MODIS LAI products have developed a series of generations, the fifth version (MODIS V005) has integrated data from both Terra and Aqua. It is proven that this version is improved with single satellite data, however, it only utilizes red and near-infrared band observations. It has been suggested

  5. The triclinic form of di-μ-aqua-bis[diaquabis(thiocyanato-κNiron(II]–1,4-bis(4H-1,2,4-triazol-4-ylbenzene (1/3

    Directory of Open Access Journals (Sweden)

    Pan Yang

    2012-08-01

    Full Text Available In the title compound, [Fe2(NCS4(H2O6]·3C10H8N6, the centrosymmetric dinuclear complex contains two FeII ions bridged by two aqua ligand O atoms, forming a four-membered ring. The slightly distorted octahedral coordination environment of the two FeII ions is completed by two monodentate aqua ligands and two thiocyanate ligands. One of the 1,4-bis(4H-1,2,4-triazol-4-ylbenzene molecules lies across an inversion center. In the crystal, O—H...N hydrogen bonds connect the components, forming a two-dimensional network parallel to (011. In addition, π–π stacking interactions involving the benzene and triazole rings, with centroid–centroid distances in the range 3.502 (5—3.787 (6 Å, connect the two-dimensional hydrogen-bonded network into a three-dimensional network.

  6. The impact of latent heating on the location, strength and structure of the Tropical Easterly Jet in the Community Atmosphere Model, version 3.1: Aqua-planet simulations

    CERN Document Server

    Rao, Samrat

    2015-01-01

    The Tropical Easterly Jet (TEJ) is a prominent atmospheric circulation feature observed during the Asian Summer Monsoon (ASM). The simulation of TEJ by the Community Atmosphere Model, version 3.1 (CAM-3.1) has been discussed in detail. Although the simulated TEJ replicates many observed features of the jet, the jet maximum is located too far to the west when compared to observation. Orography has minimal impact on the simulated TEJ hence indicating that latent heating is the crucial parameter. A series of aqua-planet experiments with increasing complexity was undertaken to understand the reasons for the extreme westward shift of the TEJ. The aqua-planet simulations show that a single heat source in the deep tropics is inadequate to explain the structure of the observed TEJ. Equatorial heating is necessary to impart a baroclinic structure and a realistic meridional structure. Jet zonal wind speeds are directly related to the magnitude of deep tropical heating. The location of peak zonal wind is influenced by o...

  7. Varying applicability of four different satellite-derived soil moisture products to global gridded crop model evaluation

    Science.gov (United States)

    Sakai, Toru; Iizumi, Toshichika; Okada, Masashi; Nishimori, Motoki; Grünwald, Thomas; Prueger, John; Cescatti, Alessandro; Korres, Wolfgang; Schmidt, Marius; Carrara, Arnaud; Loubet, Benjamin; Ceschia, Eric

    2016-06-01

    Satellite-derived daily surface soil moisture products have been increasingly available, but their applicability to global gridded crop model (GGCM) evaluation is unclear. This study compares four different soil moisture products with the flux tower site observation at 18 cropland sites across the world where either of maize, soybean, rice and wheat is grown. These products include the first and second versions of Climate Change Initiative Soil Moisture (CCISM-1 and CCISM-2) datasets distributed by the European Space Agency and two different AMSR-E (Advanced Microwave Scanning Radiometer-Earth Observing System)-derived soil moisture datasets, separately provided by the Japan Aerospace Exploration Agency (AMSRE-J) and U.S. National Aeronautics and Space Administration (AMSRE-N). The comparison demonstrates varying reliability of these products in representing major characteristics of temporal pattern of cropland soil moisture by product and crop. Possible reasons for the varying reliability include the differences in sensors, algorithms, bands and criteria used when estimating soil moisture. Both the CCISM-1 and CCISM-2 products appear the most reliable for soybean- and wheat-growing area. However, the percentage of valid data of these products is always lower than other products due to relatively strict criteria when merging data derived from multiple sources, although the CCISM-2 product has much more data with valid retrievals than the CCISM-1 product. The reliability of the AMSRE-J product is the highest for maize- and rice-growing areas and comparable to or slightly lower than the CCISM products for soybean- and wheat-growing areas. The AMSRE-N is the least reliable in most location-crop combinations. The reliability of the products for rice-growing area is far lower than that of other upland crops likely due to the extensive use of irrigation and patch distribution of rice paddy in the area examined here. We conclude that the CCISM-1, CCISM-2 and AMSRE

  8. In aqua vivo EPID dosimetry

    NARCIS (Netherlands)

    Wendling, M.; McDermott, L.N.; Mans, A.; Olaciregui-Ruiz, I.; Pecharroman-Gallego, R.; Sonke, J.J.; Stroom, J.; Herk, M. van; Mijnheer, B.J.

    2012-01-01

    PURPOSE: At the Netherlands Cancer Institute--Antoni van Leeuwenhoek Hospital in vivo dosimetry using an electronic portal imaging device (EPID) has been implemented for almost all high-energy photon treatments of cancer with curative intent. Lung cancer treatments were initially excluded, because t

  9. Poly[aqua(μ-vinylphosphonatocadmium

    Directory of Open Access Journals (Sweden)

    Laura K. Byington Congiardo

    2011-04-01

    Full Text Available The title compound, [Cd(C2H3O3P(H2O]n, was obtained from vinylphosphonic acid and cadmium nitrate. The vinyl groups project into the interlamellar space and the structure is held together via van der Waals forces. The Cd2+ ion is six-coordinate and the geometry is best described as distorted octahedral, with O—Cd—O angles falling within the range 61.72 (13–101.82 (14°. Five of the coordinated oxygen atoms originate from the phosphonate group and the sixth from a bound water molecule. Cd—O distances lie between 2.220 (3 and 2.394 (2 Å. The water molecule is hydrogen bonded to a phosphonate oxygen atom.

  10. AquaResp v2

    DEFF Research Database (Denmark)

    2013-01-01

    Free open-source software for automating aquatic intermittent flow respirometry. The software is made in the Python language, and is highly costumizable. The software and guides for build a respirometer setup can be found at aquaresp.com...

  11. AquaBase. FWS (2012)

    Data.gov (United States)

    Arctic Landscape Conservation Cooperative — The distribution and abundance of fishes in Alaska Arctic is poorly known, especially for resident species. Only a few arctic watersheds have been the subject of...

  12. Estimation of Snow Depth from Multi-source Data Fusion Based on Data Assimilation Algorithm%基于数据同化算法融合多源数据估算雪深

    Institute of Scientific and Technical Information of China (English)

    王宏伟; 黄春林; 侯金亮; 李晓英

    2016-01-01

    In snow depth studies,the smoothing effect of ground data interpolation and the low spatial resolution of remote sensing have a great impact on the estimation accuracy.In this paper,by using cloud-removed snow cover products from the fusion of MODIS (moderate resolution imaging spectro-radiometer) and AMSR-E (advanced microwave scanning radiometer-EOS) to construct virtual station,we make up the shortage of meteorological stations less and unevenness and correct the smoothing effect of Kriging interpolation.At the same time,a new scheme is proposed to improve the estimation accuracy of snow depth interpolation,which integrates data assimilation algorithm and Kriging method to fuse ground-based snow depth measurements,MODIS snow cover products.and snow depth derived from the AMSR-E microwave brightness temperature.This method was applied in the area of northern Xinjiang.Three independent stations at different elevations were chosen to evaluate fusion results.The results indicate that the proposed algorithm can effectively improve the accuracy of snow depth spatial distribution.%在积雪深度研究中,地面资料插值产生的平滑效应以及遥感空间分辨率不足的问题,在很大程度上影响着积雪深度的估计精度.本文采用中高分辨率成像光谱仪(moderate resolution imaging spectro-radiometer,MODIS)和微波扫描辐射计(advanced microwave scanning radiometer-EOS,AMSR-E)融合后的无云积雪面积产品构建虚拟站点,弥补了气象站点少且不均匀的不足,修正雪深克里金插值产生的平滑效应.同时,提出了基于数据同化算法融合以地面观测资料为基础的克里金空间插值雪深、MODIS积雪面积产品和AMSR-E微波反演雪深产品的雪深估计方法.以新疆北疆地区为研究区域进行了算法应用及验证,并选取不同海拔的站点观测资料对融合结果进行验证分析,通过均方根、偏差和相关性系数指标检证了该方法能够有效地提高雪深估计精度.

  13. Effects of Cerium on Physiological Characteristics and Microcystins Release of Anabaena flos-aquae%稀土铈对水华鱼腥藻生理特性及藻毒素释放的影响

    Institute of Scientific and Technical Information of China (English)

    吕赟; 王应军; 冷雪; 滕龙

    2012-01-01

    Rare-earth and its compounds have been widely used in various fields resulting in potential environmental pollutions, especially in water body. Thus, many more attentions have been given in recent year on water pollutions from rare-earth applications. In this paper, the effects of different initial Ce3+ concentration (0~ 10.00 mg·L‐1) on Anaboena flos-aquae were investigated in the simulated solutions in lab. The growth curve of A nabaena flos -aquae was plotted, and the physiological characteristics including the contents of phycocyanin, carotenoids, soluble protein and the activity of peroxidase (POD ) were determined. Meanwhile, the concentrations of total phosphorus (TP) and microcys-tic toxins(MC-LR) in culture medium also were measured. The results showed that, the survived quantity of Anabaena flos-aquae was significant comparing with other groups(P=0.008) when the concentration of Ce3+was 0.10 mg·L‐1, and the residual TP in culture medium reached the lowest value( 1.52 mg·L‐1) due to the utilization of P by Anabaenaflos- aquae. The mentioned four physiological indexes appeared a similar trend with the increasing of Ce3+ concentration, they all increased initially with a subsequent decrease. When the concentration of Ce3+ was 0.10 mg·L‐1, the contents of phycocyanin, soluble protein and the activity of POD reached highest. However, the contents of carotenoids could reach the highest value with the Ce3+ concentration of 0.50 mg·L‐1. The content of MC-LR was lower than the World Health Organization Standard( 1.00 μg·L‐1) in all culture medium. Thus, the effects of cerium on Anabaenaflos-aquae typically presented as the "Hormesis" effect.%随着稀土及其化合物的广泛应用,越来越多的稀土直接或间接进入水体,因而稀土对水生生态环境的影响备受关注.采用室内模拟试验,研究不同浓度(0~10.00 mg·L-1)的稀土元素铈(Ce3+)对水华鱼腥藻的影响,绘制了水华鱼腥藻的生长曲线,测定

  14. Análise da dinâmica sazonal e separabilidade espectral de algumas fitofisionomias do cerrado com índices de vegetação dos sensores MODIS/TERRA e AQUA Analysis of the seasonal dynamics and spectral separability of some savanna physiognomies with vegetation indices derived from MODIS/TERRA AND AQUA

    Directory of Open Access Journals (Sweden)

    Veraldo Liesenberg

    2007-04-01

    Full Text Available Composições de 16 dias de índices de vegetação do sensor MODerate resolution Imaging Spectroradiometer (MODIS, com resolução espacial de 1km, a bordo dos satélites TERRA e AQUA, foram usadas para caracterizar a dinâmica sazonal em 2004 de cinco fitofisionomias de Cerrado e analisar a sua separabilidade espectral. Os índices Normalized Difference Vegetation Index (NDVI e Enhanced Vegetation Index (EVI, calculados a partir dos dados dos sensores de ambas as plataformas e de uma base comum de pixels, foram comparados entre si. Os resultados indicaram que: (a dentre as fitofisionomias estudadas, a Floresta Estacional decídua apresentou uma dinâmica sazonal muito marcante em função da perda de folhas da estação chuvosa para a seca (substancial redução nos índices e do rápido verdejamento com o início da precipitação no final de outubro (rápido incremento de NDVI e EVI; (b o NDVI mostrou maior variabilidade entre as classes de vegetação do que o EVI apenas na estação seca; (c a discriminação entre as fitofisionomias melhorou da estação chuvosa para a seca; (d o NDVI foi mais eficiente do que o EVI para discriminar as classes de vegetação na estação seca, ocorrendo o contrário na estação chuvosa; e (e na maioria das datas selecionadas para estudo, não houve diferenças estatisticamente significativas entre os índices de vegetação gerados de ambas as plataformas, apesar das variações na qualidade dos pixels selecionados para as composições de 16 dias e na geometria de iluminação e de visada.MODerate-resolution Imaging Spectroradiometer (MODIS 16-day vegetation index composites with 1 km of spatial resolution from TERRA and AQUA satellites were used to characterize the seasonal dynamics of five Brazilian savanna physiognomies and to analyze their spectral separability in 2004. The Normalized Difference Vegetation Index (NDVI and Enhanced Vegetation Index (EVI, using data from both platforms and from a

  15. 中国风云二号SVISSR传感器热红外波段与AIRS/Aqua的交叉辐射定标%Intercalibration of SVISRR/FY-2 Thermal Infrared Channels with AIRS/Aqua Channels

    Institute of Scientific and Technical Information of China (English)

    蒋耿明; 金亚秋

    2012-01-01

    对高光谱卷积法进行了改进,实现了卫星影像之间的亚像素匹配和粗差的剔除,对搭载在中国“风云二号”(FY-)C、D和E星上的伸展的可见光和红外自旋转扫描辐射计(SVISSR)的两个热红外波段IRl(~10.9/am)和IR2(~11.9μm)与搭栽在Aqua卫星上的大气红外探空仪(AIRS)高光谱波段进行交叉辐射定标。基于SVISSR/FY-2和AIRS/Aqua对地观测的几何特性,选取研究区域覆盖41.5°~149.5°E、10°S--10°N的范围,利用该研究区域2006年12月、2007年9月和12月、2009年9月和2010年5月的SVISSR/FY2标称数据和AIRS/Aqua红外1B数据,在同地点、同一天太阳天顶角之差的绝对值小于2°、观测天顶角之差的绝对值小于3°和相对方位角之差的绝对值小于6°的匹配条件下,提取匹配的观测点对,然后对匹配观测点对进行回归分析,得到交叉辐射定标系数。结果表明:SVISSR/FY-2波段观测值与卷积得到的AIRS/Aqua观测值之间高度线性相关,且SVISSR/FY-2的两个热红外波段相对于AIRS/Aqua波段存在定标偏差。并给出了交叉辐射定标系数。%Intercalibration of the thermal infrared window channels 1 (-10.9 μm) and 2 (-11.9 μm) of the Stretched Visible and Infrared Spin Scan Radiometer on FengYun 2 (SVISSR/FY-2) satellites C, D and E with the hyper-spectral channels of the Atmospheric InfraRed Sounder on board Aqua (AIRS/Aqua) was developed using the High Spectral Convolution (HSC) method, which was improved in two aspects,sub-pixel spatial matching and automatic removal of the measurement pairs with coarse errors. According to the view geometries of SVISSR/FY-2 and AIRS/Aqua, with the study area longitude from 41.5°E to 149.5°E and the latitude from 10°S to 10°N was selected. To transfer the calibration coefficients from AIRS/Aqua channels to SVISSR/FY-2 channels,the SVISSR/FY-2 Nor- malized

  16. Reprocessing the Historical Satellite Passive Microwave Record at Enhanced Spatial Resolutions using Image Reconstruction

    Science.gov (United States)

    Hardman, M.; Brodzik, M. J.; Long, D. G.; Paget, A. C.; Armstrong, R. L.

    2015-12-01

    Beginning in 1978, the satellite passive microwave data record has been a mainstay of remote sensing of the cryosphere, providing twice-daily, near-global spatial coverage for monitoring changes in hydrologic and cryospheric parameters that include precipitation, soil moisture, surface water, vegetation, snow water equivalent, sea ice concentration and sea ice motion. Currently available global gridded passive microwave data sets serve a diverse community of hundreds of data users, but do not meet many requirements of modern Earth System Data Records (ESDRs) or Climate Data Records (CDRs), most notably in the areas of intersensor calibration, quality-control, provenance and consistent processing methods. The original gridding techniques were relatively primitive and were produced on 25 km grids using the original EASE-Grid definition that is not easily accommodated in modern software packages. Further, since the first Level 3 data sets were produced, the Level 2 passive microwave data on which they were based have been reprocessed as Fundamental CDRs (FCDRs) with improved calibration and documentation. We are funded by NASA MEaSUREs to reprocess the historical gridded data sets as EASE-Grid 2.0 ESDRs, using the most mature available Level 2 satellite passive microwave (SMMR, SSM/I-SSMIS, AMSR-E) records from 1978 to the present. We have produced prototype data from SSM/I and AMSR-E for the year 2003, for review and feedback from our Early Adopter user community. The prototype data set includes conventional, low-resolution ("drop-in-the-bucket" 25 km) grids and enhanced-resolution grids derived from the two candidate image reconstruction techniques we are evaluating: 1) Backus-Gilbert (BG) interpolation and 2) a radiometer version of Scatterometer Image Reconstruction (SIR). We summarize our temporal subsetting technique, algorithm tuning parameters and computational costs, and include sample SSM/I images at enhanced resolutions of up to 3 km. We are actively

  17. Combination of multi-sensor remote sensing data for drought monitoring over Southwest China

    Science.gov (United States)

    Hao, Cui; Zhang, Jiahua; Yao, Fengmei

    2015-03-01

    Drought is one of the most frequent climate-related disasters occurring in Southwest China, where the occurrence of drought is complex because of the varied landforms, climates and vegetation types. To monitor the comprehensive information of drought from meteorological to vegetation aspects, this paper intended to propose the optimized meteorological drought index (OMDI) and the optimized vegetation drought index (OVDI) from multi-source satellite data to monitor drought in three bio-climate regions of Southwest China. The OMDI and OVDI were integrated with parameters such as precipitation, temperature, soil moisture and vegetation information, which were derived from Tropical Rainfall Measuring Mission (TRMM), Moderate Resolution Imaging Spectroradiometer Land Surface Temperature (MODIS LST), AMSR-E Soil Moisture (AMSR-E SM), the soil moisture product of China Land Soil Moisture Assimilation System (CLSMAS), and MODIS Normalized Difference Vegetation Index (MODIS NDVI), respectively. Different sources of satellite data for one parameter were compared with in situ drought indices in order to select the best data source to derive the OMDI and OVDI. The Constrained Optimization method was adopted to determine the optimal weights of each satellite-based index generating combined drought indices. The result showed that the highest positive correlation and lowest root mean square error (RMSE) between the OMDI and 1-month standardized precipitation evapotranspiration index (SPEI-1) was found in three regions of Southwest China, suggesting that the OMDI was a good index in monitoring meteorological drought; in contrast, the OVDI was best correlated to 3-month SPEI (SPEI-3), and had similar trend with soil relative water content (RWC) in temporal scale, suggesting it a potential indicator of agricultural drought. The spatial patterns of OMDI and OVDI along with the comparisons of SPEI-1 and SPEI-3 for different months in one year or one month in different years showed

  18. Soil as a natural rain gauge: Estimating global rainfall from satellite soil moisture data

    Science.gov (United States)

    Brocca, Luca; Ciabatta, Luca; Massari, Christian; Moramarco, Tommaso; Hahn, Sebastian; Hasenauer, Stefan; Kidd, Richard; Dorigo, Wouter; Wagner, Wolfgang; Levizzani, Vincenzo

    2014-05-01

    Measuring precipitation intensity is not straightforward; and over many areas, ground observations are lacking and satellite observations are used to fill this gap. The most common way of retrieving rainfall is by addressing the problem "top-down" by inverting the atmospheric signals reflected or radiated by atmospheric hydrometeors. However, most applications are interested in how much water reaches the ground, a problem that is notoriously difficult to solve from a top-down perspective. In this study, a novel "bottom-up" approach is proposed that, by doing "hydrology backward," uses variations in soil moisture (SM) sensed by microwave satellite sensors to infer preceding rainfall amounts. In other words, the soil is used as a natural rain gauge. Three different satellite SM data sets from the Advanced SCATterometer (ASCAT), the Advanced Microwave Scanning Radiometer (AMSR-E), and the Microwave Imaging Radiometer with Aperture Synthesis are used to obtain three new daily global rainfall products. The "First Guess Daily" product of the Global Precipitation Climatology Centre (GPCC) is employed as main benchmark in the validation period 2010-2011 for determining the continuous and categorical performance of the SM-derived rainfall products by considering the 5 day accumulated values. The real-time version of the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis product, i.e., the TRMM-3B42RT, is adopted as a state-of-the-art satellite rainfall product. The SM-derived rainfall products show good Pearson correlation values (R) with the GPCC data set, mainly in areas where SM retrievals are found to be accurate. The global median R values (in the latitude band ±50°) are equal to 0.54, 0.28, and 0.31 for ASCAT-, AMSR-E-, and SMOS-derived products, respectively. For comparison, the median R for the TRMM-3B42RT product is equal to 0.53. Interestingly, the SM-derived products are found to outperform TRMM-3B42RT in terms of average global

  19. Overview of Japanese Earth observation programs

    Science.gov (United States)

    Shimoda, Haruhisa

    2015-10-01

    Six programs, i.e. AMSR-E, ASTER, GOSAT, GCOM-W1, GPM and ALOS-2 are going on in Japanese Earth Observation programs. ASTER has lost its short wave infrared channels. AMSR-E stopped its operation, but it started its operation from Sep. 2012. GCOM-W1 was launched on 18, May, 2012 and is operating well as well as GOSAT. ALOS (Advanced Land Observing Satellite) was successfully launched on 24th Jan. 2006. ALOS carries three instruments, i.e., PRISM (Panchromatic Remote Sensing Instrument for Stereo Mapping), AVNIR-2 (Advanced Visible and Near Infrared Radiometer), and PALSAR (Phased Array L band Synthetic Aperture Radar). Unfortunately, ALOS has stopped its operation on 22nd, April, 2011 by power loss. GOSAT (Greenhouse Gas Observation Satellite) was successfully launched on 29, January, 2009. GOSAT carries 2 instruments, i.e. a green house gas sensor (TANSO-FTS) and a cloud/aerosol imager (TANSO-CAI). The main sensor is a Fourier transform spectrometer (FTS) and covers 0.76 to 15 μm region with 0.2 to 0.5 cm-1 resolution. SMILES (Super-conducting Millimeter wave Emission Spectrometer) was launched on September 2009 to ISS and started the observation, but stopped its operation on April 2010. GPM (Global Precipitation Mission) core satellite was launched on Feb. 2014. GPM is a joint project with NASA and carries two instruments. JAXA has developed DPR (Dual frequency Precipitation Radar) which is a follow on of PR on TRMM. ALOS F/O satellites are divided into two satellites, i.e. SAR and optical satellites. The first one of ALOS F/O is called ALOS 2 and carries L-band SAR. It was launched on May 2014. JAXA is planning to launch follow on of optical sensors. It is now called Advanced Optical Satellite and the planned launch date is fiscal 2019. Other future satellites are GCOM-C1 (ADEOS-2 follow on), GOSAT-2 and EarthCare. GCOM-C1 will be launched on 2016 and GOSAT-2 will be launched on 2017. Another project is EarthCare. It is a joint project with ESA and JAXA is

  20. NASA Team 2 Sea Ice Concentration Algorithm Retrieval Uncertainty

    Science.gov (United States)

    Brucker, Ludovic; Cavalieri, Donald J.; Markus, Thorsten; Ivanoff, Alvaro

    2014-01-01

    Satellite microwave radiometers are widely used to estimate sea ice cover properties (concentration, extent, and area) through the use of sea ice concentration (IC) algorithms. Rare are the algorithms providing associated IC uncertainty estimates. Algorithm uncertainty estimates are needed to assess accurately global and regional trends in IC (and thus extent and area), and to improve sea ice predictions on seasonal to interannual timescales using data assimilation approaches. This paper presents a method to provide relative IC uncertainty estimates using the enhanced NASA Team (NT2) IC algorithm. The proposed approach takes advantage of the NT2 calculations and solely relies on the brightness temperatures (TBs) used as input. NT2 IC and its associated relative uncertainty are obtained for both the Northern and Southern Hemispheres using the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) TB. NT2 IC relative uncertainties estimated on a footprint-by-footprint swath-by-swath basis were averaged daily over each 12.5-km grid cell of the polar stereographic grid. For both hemispheres and throughout the year, the NT2 relative uncertainty is less than 5%. In the Southern Hemisphere, it is low in the interior ice pack, and it increases in the marginal ice zone up to 5%. In the Northern Hemisphere, areas with high uncertainties are also found in the high IC area of the Central Arctic. Retrieval uncertainties are greater in areas corresponding to NT2 ice types associated with deep snow and new ice. Seasonal variations in uncertainty show larger values in summer as a result of melt conditions and greater atmospheric contributions. Our analysis also includes an evaluation of the NT2 algorithm sensitivity to AMSR-E sensor noise. There is a 60% probability that the IC does not change (to within the computed retrieval precision of 1%) due to sensor noise, and the cumulated probability shows that there is a 90% chance that the IC varies by less than

  1. Improving terrestrial evaporation estimates over continental Australia through assimilation of SMOS soil moisture

    Science.gov (United States)

    Martens, B.; Miralles, D.; Lievens, H.; Fernández-Prieto, D.; Verhoest, N. E. C.

    2016-06-01

    Terrestrial evaporation is an essential variable in the climate system that links the water, energy and carbon cycles over land. Despite this crucial importance, it remains one of the most uncertain components of the hydrological cycle, mainly due to known difficulties to model the constraints imposed by land water availability on terrestrial evaporation. The main objective of this study is to assimilate satellite soil moisture observations from the Soil Moisture and Ocean Salinity (SMOS) mission into an existing evaporation model. Our over-arching goal is to find an optimal use of satellite soil moisture that can help to improve our understanding of evaporation at continental scales. To this end, the Global Land Evaporation Amsterdam Model (GLEAM) is used to simulate evaporation fields over continental Australia for the period September 2010-December 2013. SMOS soil moisture observations are assimilated using a Newtonian Nudging algorithm in a series of experiments. Model estimates of surface soil moisture and evaporation are validated against soil moisture probe and eddy-covariance measurements, respectively. Finally, an analogous experiment in which Advanced Microwave Scanning Radiometer (AMSR-E) soil moisture is assimilated (instead of SMOS) allows to perform a relative assessment of the quality of both satellite soil moisture products. Results indicate that the modelled soil moisture from GLEAM can be improved through the assimilation of SMOS soil moisture: the average correlation coefficient between in situ measurements and the modelled soil moisture over the complete sample of stations increased from 0.68 to 0.71 and a statistical significant increase in the correlations is achieved for 17 out of the 25 individual stations. Our results also suggest a higher accuracy of the ascending SMOS data compared to the descending data, and overall higher quality of SMOS compared to AMSR-E retrievals over Australia. On the other hand, the effect of soil moisture data

  2. Pan-Arctic linkages between snow accumulation and growing-season air temperature, soil moisture and vegetation

    Directory of Open Access Journals (Sweden)

    K. A. Luus

    2013-11-01

    Full Text Available Arctic field studies have indicated that the air temperature, soil moisture and vegetation at a site influence the quantity of snow accumulated, and that snow accumulation can alter growing-season soil moisture and vegetation. Climate change is predicted to bring about warmer air temperatures, greater snow accumulation and northward movements of the shrub and tree lines. Understanding the responses of northern environments to changes in snow and growing-season land surface characteristics requires: (1 insights into the present-day linkages between snow and growing-season land surface characteristics; and (2 the ability to continue to monitor these associations over time across the vast pan-Arctic. The objective of this study was therefore to examine the pan-Arctic (north of 60° N linkages between two temporally distinct data products created from AMSR-E satellite passive microwave observations: GlobSnow snow water equivalent (SWE, and NTSG growing-season AMSR-E Land Parameters (air temperature, soil moisture and vegetation transmissivity. Due to the complex and interconnected nature of processes determining snow and growing-season land surface characteristics, these associations were analyzed using the modern nonparametric technique of alternating conditional expectations (ACE, as this approach does not impose a predefined analytic form. Findings indicate that regions with lower vegetation transmissivity (more biomass at the start and end of the growing season tend to accumulate less snow at the start and end of the snow season, possibly due to interception and sublimation. Warmer air temperatures at the start and end of the growing season were associated with diminished snow accumulation at the start and end of the snow season. High latitude sites with warmer mean annual growing-season temperatures tended to accumulate more snow, probably due to the greater availability of water vapor for snow season precipitation at warmer locations. Regions

  3. Disaggregation Of Passive Microwave Soil Moisture For Use In Watershed Hydrology Applications

    Science.gov (United States)

    Fang, Bin

    In recent years the passive microwave remote sensing has been providing soil moisture products using instruments on board satellite/airborne platforms. Spatial resolution has been restricted by the diameter of antenna which is inversely proportional to resolution. As a result, typical products have a spatial resolution of tens of kilometers, which is not compatible for some hydrological research applications. For this reason, the dissertation explores three disaggregation algorithms that estimate L-band passive microwave soil moisture at the subpixel level by using high spatial resolution remote sensing products from other optical and radar instruments were proposed and implemented in this investigation. The first technique utilized a thermal inertia theory to establish a relationship between daily temperature change and average soil moisture modulated by the vegetation condition was developed by using NLDAS, AVHRR, SPOT and MODIS data were applied to disaggregate the 25 km AMSR-E soil moisture to 1 km in Oklahoma. The second algorithm was built on semi empirical physical models (NP89 and LP92) derived from numerical experiments between soil evaporation efficiency and soil moisture over the surface skin sensing depth (a few millimeters) by using simulated soil temperature derived from MODIS and NLDAS as well as AMSR-E soil moisture at 25 km to disaggregate the coarse resolution soil moisture to 1 km in Oklahoma. The third algorithm modeled the relationship between the change in co-polarized radar backscatter and the remotely sensed microwave change in soil moisture retrievals and assumed that change in soil moisture was a function of only the canopy opacity. The change detection algorithm was implemented using aircraft based the remote sensing data from PALS and UAVSAR that were collected in SMPAVEX12 in southern Manitoba, Canada. The PALS L-band h-polarization radiometer soil moisture retrievals were disaggregated by combining them with the PALS and UAVSAR L

  4. Crystal structure of 4-(di­methyl­amino)­pyridinium cis-di­aqua­bis­(oxalato-κ2 O,O′)ferrate(III) hemihydrate

    Science.gov (United States)

    Djomo, Edith Dimitri; Capet, Frédéric; Nenwa, Justin; Bélombé, Michel M.; Foulon, Michel

    2015-01-01

    The FeIII ions in the hybrid title salt, (C7H11N2)[Fe(C2O4)2(H2O)2]·0.5H2O, show a distorted octa­hedral coordination environment, with four O atoms from two chelating oxalate dianions and two O atoms from two cis aqua ligands. The average Fe—O(oxalate) bond length [2.00 (2) Å] is shorter than the average Fe—O(water) bond length [2.027 (19) Å]. The ionic components are connected via inter­molecular N—H⋯O and O—H⋯O hydrogen bonds into a three-dimensional network. PMID:26396759

  5. Crystal structure of 4-(di­methyl­amino)­pyridinium cis-di­aqua­bis­(oxalato-κ2 O,O′)ferrate(III) hemihydrate

    OpenAIRE

    Edith Dimitri Djomo; Frédéric Capet; Justin Nenwa; Bélombé, Michel M.; Michel Foulon

    2015-01-01

    The FeIII ions in the hybrid title salt, (C7H11N2)[Fe(C2O4)2(H2O)2]·0.5H2O, show a distorted octahedral coordination environment, with four O atoms from two chelating oxalate dianions and two O atoms from two cis aqua ligands. The average Fe—O(oxalate) bond length [2.00 (2) Å] is shorter than the average Fe—O(water) bond length [2.027 (19) Å]. The ionic components are connected via intermolecular N—H...O and O—H...O hydrogen bonds into a three-dimensional network.

  6. 3种长链脂肪酸对水华鱼腥藻的生长影响%Effects of Three Long Chain Fatty Acids on the Growth of Anabaena Flos-aquae

    Institute of Scientific and Technical Information of China (English)

    罗万芬; 曾仁权

    2011-01-01

    Effects of three long chain fatty acids on the growth of Anabaena glos-aquae in the cell density of 2. 575 × 106 cells/mL afe studied by dodecanoic acid, 9,12-octadecadienoic acid, 9, 12,15-octadecatrienoic acid, the results show that three long chain fatty acid on the inhibition of anabaena f los-aquae are different. The inhibiting shows more inhibitory effect in high concentration. In the some time,the inhibition is as follows: dodecanoic acid > octadecatrienoic acid>octadecadienoic acid.%研究了十二酸(月桂酸)、9,12-十八碳二烯酸、9,12,15-十八碳三烯酸3种长链脂肪酸对密度为2.575×106个/mL水华鱼腥藻的生长影响.结果表明,这3种长链脂肪酸对水华鱼腥藻都有不同程度的抑制作用,其浓度越大效果越明显.在同一时间内,这3种脂肪酸对水华鱼腥藻的抑藻作用大小顺序为:十二酸>十八碳三烯酸>十八碳二烯酸,十二酸对水华鱼腥藻的生长有很强的抑制作用.

  7. Detection of Metal Ions in Silica by Reverse Aqua Regia Digestion and Ion Chromatography%硅胶中六种金属离子反王水消解-离子色谱检测方法的研究

    Institute of Scientific and Technical Information of China (English)

    马超; 贾艳侠; 唐涛; 孙元社; 张维冰; 李英杰; 李彤

    2012-01-01

    Silica is the most commonly used HPLC column packing and trace metal ion impurities in silica can seriously affect the performance of chromatographic separation. It is important to develop a rapid, highly selective and sensitive method for the quality control of silica. In this paper, an analytical method for the determination of metal ions in silica by ion chromatography with reverse aqua regia digestion was proposed. The pretreatment method of sample was systematically studied in detail. The optimum conditions for the pretreatment were as follow: digestion reagent was hydrofluoric acid and reverse aqua regia, reducing agent was ascorbic acid. Under the optimized conditions, six metal ions (sodium, zinc, potassium, iron, magnesium and calcium) were obtained good baseline resoluions. The results demonstrated that the proposed method was simple,rapid,sensitive and reproducible for determination of metal ions in actual silica samples.%本文建立了硅胶中金属离子反王水消解-离子色谱检测的方法.系统研究了硅胶的最佳前处理条件,选择消解试剂为氢氟酸和反王水,还原剂为抗坏血酸,实现了Na+、Zn2+、K+、Fe2+、Mg2+和Ca2+六种金属离子基线分离.该方法简便快速、灵敏、重现性好.进一步以该方法对实际硅胶样品中微量金属离子测定,获得较好的结果.

  8. Evaluating the utility of satellite soil moisture retrievals over irrigated areas and the ability of land data assimilation methods to correct for unmodeled processes

    Science.gov (United States)

    Kumar, S. V.; Peters-Lidard, C. D.; Santanello, J. A.; Reichle, R. H.; Draper, C. S.; Koster, R. D.; Nearing, G.; Jasinski, M. F.

    2015-11-01

    Earth's land surface is characterized by tremendous natural heterogeneity and human-engineered modifications, both of which are challenging to represent in land surface models. Satellite remote sensing is often the most practical and effective method to observe the land surface over large geographical areas. Agricultural irrigation is an important human-induced modification to natural land surface processes, as it is pervasive across the world and because of its significant influence on the regional and global water budgets. In this article, irrigation is used as an example of a human-engineered, often unmodeled land surface process, and the utility of satellite soil moisture retrievals over irrigated areas in the continental US is examined. Such retrievals are based on passive or active microwave observations from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E), the Advanced Microwave Scanning Radiometer 2 (AMSR2), the Soil Moisture Ocean Salinity (SMOS) mission, WindSat and the Advanced Scatterometer (ASCAT). The analysis suggests that the skill of these retrievals for representing irrigation effects is mixed, with ASCAT-based products somewhat more skillful than SMOS and AMSR2 products. The article then examines the suitability of typical bias correction strategies in current land data assimilation systems when unmodeled processes dominate the bias between the model and the observations. Using a suite of synthetic experiments that includes bias correction strategies such as quantile mapping and trained forward modeling, it is demonstrated that the bias correction practices lead to the exclusion of the signals from unmodeled processes, if these processes are the major source of the biases. It is further shown that new methods are needed to preserve the observational information about unmodeled processes during data assimilation.

  9. 溶藻细菌L7对水华鱼腥藻氮代谢的影响%Effects of the algicidal bacterial strain L7 on nitrogen metabolism of Anabaena flos-aquae

    Institute of Scientific and Technical Information of China (English)

    张涵之; 潘伟斌; 陈宝华

    2012-01-01

    [目的]进一步探明藻菌关系,研究溶藻细菌对藻类氮代谢的影响及其作用机制.[方法]将水华鱼腥藻和溶藻细菌L7按两种比例接种入BG11培养液中,在室内进行共培养(藻细胞初始密度为1.21×108 cells/L;溶藻细菌L7初始密度分别为1.75×107、1.75×108 CFU/mL).连续7d测定藻细胞数、异形胞频率和藻细胞内的硝酸还原酶(NR)活性、谷氨酰胺合成酶(GS)活性、谷氨酸合成酶(GOGAT)活性、蛋白质含量、丙二醛(MDA)含量.[结果]低密度溶藻细菌L7能够促进藻生长(第7天藻细胞密度是对照组的1.58倍),增加异形胞频率(第7天高于对照组66.67%);高密度则会抑制藻生长(第7天藻细胞密度相比对照组下降98.84%),降低异形胞频率(第7天为0).在藻细胞内氮代谢关键酶活性方面,接种后2-5 d,两处理组中藻细胞内NR和GOGAT活性均极显著高于对照组(P<0.01);接种后0-5 d,高密度处理组的GS活性极显著高于对照组(P<0.01),而低密度处理组的则在大部分时间内极显著低于对照组(P<0.01).在整个实验期内,低密度处理组中藻细胞内蛋白质含量一直极显著高于对照组(P<0.01);而在高密度处理组中,除第5天外,细胞内蛋白质含量则全部极显著低于对照组(P<0.01).接种后2-4 d,高密度处理组中藻细胞内MDA含量呈现上升趋势,并极显著高于其余两组(P<0.01).[结论]低密度溶藻细菌L7能够提高水华鱼腥藻对氮源的需求,加速蛋白质合成,促进氮代谢;而高密度溶藻细菌L7会对藻细胞产生过氧化伤害,阻碍蛋白质合成和氮代谢过程.%[Objective] The influence mechanism of the algicidal bacterial strain L7 on nitrogen metabolism of Anabaena flos-aquae were investigated to understand the interaction of cyanobacteria-bacteria.[Methods] The algicidal bacterial strain L7 and Anabaena flos-aquae with different ratio were inoculated into BG11 liquid medium.The initial

  10. Use of acoustic backscatter and vertical velocity to estimate concentration and dynamics of suspended solids in Upper Klamath Lake, south-central Oregon: Implications for Aphanizomenon flos-aquae

    Science.gov (United States)

    Wood, Tamara M.; Gartner, Jeffrey W.

    2010-01-01

    Vertical velocity and acoustic backscatter measurements by acoustic Doppler current profilers were used to determine seasonal, subseasonal (days to weeks), and diel variation in suspended solids in a freshwater lake where massive cyanobacterial blooms occur annually. During the growing season, the suspended material in the lake is dominated by the buoyancy-regulating cyanobacteria, Aphanizomenon flos-aquae. Measured variables (water velocity, relative backscatter [RB], wind speed, and air and water temperatures) were averaged over the deployment season at each sample time of day to determine average diel cycles. Phase shifts between diel cycles in RB and diel cycles in wind speed, vertical water temperature differences (delta T(degree)), and horizontal current speeds were found by determining the lead or lag that maximized the linear correlation between the respective diel cycles. Diel cycles in RB were more in phase with delta T(degree) cycles, and, to a lesser extent, wind cycles, than to water current cycles but were out of phase with the cycle that would be expected if the vertical movement of buoyant cyanobacteria colonies was controlled primarily by light. Clear evidence of a diel cycle in vertical velocity was found only at the two deepest sites in the lake. Cycles of vertical velocity, where present, were out of phase with expected vertical motion of cyanobacterial colonies based on the theoretical cycle for light-driven vertical movement. This suggests that water column stability and turbulence were more important factors in controlling vertical distribution of colonies than light. Variations at subseasonal time scales were determined by filtering data to pass periods between 1.2 and 15 days. At subseasonal time scales, correlations between RB and currents or air temperature were consistent with increased concentration of cyanobacterial colonies near the surface when water column stability increased (higher air temperatures or weaker currents) and

  11. Indonesian drought monitoring from space. A report of SAFE activity: Assessment of drought impact on rice production in Indonesia by satellite remote sensing and dissemination with web-GIS

    International Nuclear Information System (INIS)

    Long droughts experienced in Indonesia in the past are identified as one of the main factors in the failure of rice production. In this regard, special attention to monitor the condition is encouraged to reduce the damage. Currently, various satellite data and approaches can withdraw valuable information for monitoring and anticipating drought hazards. Two types of drought, Meteorology and Agriculture, have been assessed. During the last 10 years, daily and monthly rainfall data derived from TRMM and GSMaP. MTSAT and AMSR-E data have been analyzed to identify meteorological drought. Agricultural drought has been studied by observing the character of some indices (EVI, VCI, VHI, LST, and NDVI) of sixteen-day and monthly MODIS data at a period of 5 years (2009 – 2013). Network for data transfer has been built between LAPAN (data provider), ICALRD (implementer), IAARD Cloud Computing, and University of Tokyo (technical supporter). A Web-GIS based Drought Monitoring Information System has been developed to disseminate the information to end users. This paper describes the implementation of remote sensing drought monitoring model and development of Web-GIS and satellite based information system

  12. [Study of the microwave emissivity characteristics of vegetation over the Northern Hemisphere].

    Science.gov (United States)

    Shi, Li-Juan; Qiu, Yu-Bao; Shi, Jian-Cheng

    2013-05-01

    The microwave emissivity is a function of structure, water content, and surface roughness, and all these factors have obvious seasonal variations. In the present study, the half-month averaged emissivities in summer and winter of 2003 over the vegetation of Northern Hemisphere were estimated using Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) combined with IGBP (International Geosphere-Biosphere Project labels) land classification data. Then the emissivities of vegetation land covers at different frequencies, the polarization and their seasonal variations were analyzed respectively. The results show that the emissivities of vegetation increase with the increase in frequencies, and decline with the frequency increasing over snow region. In summer, the vegetation emissivity at V-polarization of 89 GHz is larger than 0.944, and all emissivities are relatively stable and the RMSE of time series emissivity variation is less than 0.007 2. In winter, emissivities decrease over snow covered area, especially for higher frequencies. Furthermore, with the increase in vegetation density, the emissivities increase and emissivity polarization difference decreases.

  13. Quantifying Uncertainties in Land Surface Microwave Emissivity Retrievals

    Science.gov (United States)

    Tian, Yudong; Peters-Lidard, Christa D.; Harrison, Kenneth W.; Prigent, Catherine; Norouzi, Hamidreza; Aires, Filipe; Boukabara, Sid-Ahmed; Furuzawa, Fumie A.; Masunaga, Hirohiko

    2012-01-01

    Uncertainties in the retrievals of microwave land surface emissivities were quantified over two types of land surfaces: desert and tropical rainforest. Retrievals from satellite-based microwave imagers, including SSM/I, TMI and AMSR-E, were studied. Our results show that there are considerable differences between the retrievals from different sensors and from different groups over these two land surface types. In addition, the mean emissivity values show different spectral behavior across the frequencies. With the true emissivity assumed largely constant over both of the two sites throughout the study period, the differences are largely attributed to the systematic and random errors in the retrievals. Generally these retrievals tend to agree better at lower frequencies than at higher ones, with systematic differences ranging 14% (312 K) over desert and 17% (320 K) over rainforest. The random errors within each retrieval dataset are in the range of 0.52% (26 K). In particular, at 85.0/89.0 GHz, there are very large differences between the different retrieval datasets, and within each retrieval dataset itself. Further investigation reveals that these differences are mostly likely caused by rain/cloud contamination, which can lead to random errors up to 1017 K under the most severe conditions.

  14. ICESat Observations of Seasonal and Interannual Variations of Sea-Ice Freeboard and Estimated Thickness in the Weddell Sea, Antarctica (2003-2009)

    Science.gov (United States)

    Yi, Donghui; Robbins, John W.

    2010-01-01

    Sea-ice freeboard heights for 17 ICESat campaign periods from 2003 to 2009 are derived from ICESat data. Freeboard is combined with snow depth from Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) data and nominal densities of snow, water and sea ice, to estimate sea-ice thickness. Sea-ice freeboard and thickness distributions show clear seasonal variations that reflect the yearly cycle of growth and decay of the Weddell Sea (Antarctica) pack ice. During October-November, sea ice grows to its seasonal maximum both in area and thickness; the mean freeboards are 0.33-0.41 m and the mean thicknesses are 2.10-2.59 m. During February-March, thinner sea ice melts away and the sea-ice pack is mainly distributed in the west Weddell Sea; the mean freeboards are 0.35-0.46 m and the mean thicknesses are 1.48-1.94 m. During May-June, the mean freeboards and thicknesses are 0.26-0.29 m and 1.32-1.37 m, respectively. The 6 year trends in sea-ice extent and volume are (0.023+/-0.051) x 10(exp 6)sq km/a (0.45%/a) and (0.007+/-1.0.092) x 10(exp 3)cu km/a (0.08%/a); however, the large standard deviations indicate that these positive trends are not statistically significant.

  15. Estimation of Sea Ice Thickness Distributions through the Combination of Snow Depth and Satellite Laser Altimetry Data

    Science.gov (United States)

    Kurtz, Nathan T.; Markus, Thorsten; Cavalieri, Donald J.; Sparling, Lynn C.; Krabill, William B.; Gasiewski, Albin J.; Sonntag, John G.

    2009-01-01

    Combinations of sea ice freeboard and snow depth measurements from satellite data have the potential to provide a means to derive global sea ice thickness values. However, large differences in spatial coverage and resolution between the measurements lead to uncertainties when combining the data. High resolution airborne laser altimeter retrievals of snow-ice freeboard and passive microwave retrievals of snow depth taken in March 2006 provide insight into the spatial variability of these quantities as well as optimal methods for combining high resolution satellite altimeter measurements with low resolution snow depth data. The aircraft measurements show a relationship between freeboard and snow depth for thin ice allowing the development of a method for estimating sea ice thickness from satellite laser altimetry data at their full spatial resolution. This method is used to estimate snow and ice thicknesses for the Arctic basin through the combination of freeboard data from ICESat, snow depth data over first-year ice from AMSR-E, and snow depth over multiyear ice from climatological data. Due to the non-linear dependence of heat flux on ice thickness, the impact on heat flux calculations when maintaining the full resolution of the ICESat data for ice thickness estimates is explored for typical winter conditions. Calculations of the basin-wide mean heat flux and ice growth rate using snow and ice thickness values at the 70 m spatial resolution of ICESat are found to be approximately one-third higher than those calculated from 25 km mean ice thickness values.

  16. A New Approach in Downscaling Microwave Soil Moisture Product using Machine Learning

    Science.gov (United States)

    Abbaszadeh, Peyman; Yan, Hongxiang; Moradkhani, Hamid

    2016-04-01

    Understating the soil moisture pattern has significant impact on flood modeling, drought monitoring, and irrigation management. Although satellite retrievals can provide an unprecedented spatial and temporal resolution of soil moisture at a global-scale, their soil moisture products (with a spatial resolution of 25-50 km) are inadequate for regional study, where a resolution of 1-10 km is needed. In this study, a downscaling approach using Genetic Programming (GP), a specialized version of Genetic Algorithm (GA), is proposed to improve the spatial resolution of satellite soil moisture products. The GP approach was applied over a test watershed in United States using the coarse resolution satellite data (25 km) from Advanced Microwave Scanning Radiometer - EOS (AMSR-E) soil moisture products, the fine resolution data (1 km) from Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation index, and ground based data including land surface temperature, vegetation and other potential physical variables. The results indicated the great potential of this approach to derive the fine resolution soil moisture information applicable for data assimilation and other regional studies.

  17. AIRS total precipitable water over high latitudes

    Science.gov (United States)

    Ye, H.; Fetzer, E. J.; Bromwich, D. H.; Fishbein, E.; Olsen, E. T.; Granger, S.; Lee, S.; Lambrigtsen, B.; Chen, L.

    2006-12-01

    Given the importance of atmospheric conditions over the Arctic and Antarctica to the global climate system, hydrological cycles, and cryopspheric dynamics, and the poor coverage of traditional data over these region, AIRS data will play a significant role in filling the information gaps. In this study, we examine the quality of AIRS total atmospheric precipitable water (PWV) and explore its potential applications over the Antarctica and Arctic. For Antarctica, both Level II matching files and Level III gridded products of AIRS are compared with radiosonde records at Dome C and ECMWF's analysis products during December 10, 2003 to January 26, 2004. Results will testify to the quality of AIRS moisture data over glacial surfaces. For the Arctic region, AIRS level III data are used to compare with AMSR-E data and ECMWF analysis product during September of 2004. Results will reveal the quality of AIRS data over high-latitude water, sea ice, and land surfaces. The potential of AIRS data to improve model simulation will be discussed.

  18. Moisture Structure of the Quasi-biweekly Mode Revealed by AIRS in Western Pacific

    Institute of Scientific and Technical Information of China (English)

    TAO Li; Xiouhua FU; LU Weisong

    2009-01-01

    Using Atmospheric Infrared Sounder (AIRS) humidity profiles, rainfall from the Tropical Rainfall Measuring Mission (TRMM) Global Precipitation Index (GPI), Quick Scattcrometer (QSCAT) satellite-observed surface winds, and SST from the Advanced Microwave Scanning Radiometer for NASA's Earth Observing System (AMSR_E), we analyzed the structure of the summer quasi-biweekly mode (QBM) over the western Pacific in 2003-2004. We find that the signal of 10-20-day oscillations in the western Pacific originates from the Philippine Sea, and propagates northwestward toward South China. The AIRS data reveal that the boundary-layer moisture provides preconditioning for QBM propagation, and leads the mid-troposphere moisture during the entire QBM cycle. The positive SST anomaly leads or is in-phase with the boundarylayer moistening, and may be a major contributor. Most likely, the 10-20-day SST anomaly positively feeds back to the atmosphere by moistening the boundary layer, destabilizing the troposphere, and leading the QBM to propagate northwestward in the western North Pacific. However, the ECMWF/TOGA (Tropical Ocean and Global Atmosphere) analysis does not display boundary-layer (BL) moisture anomalies leading the mid-troposphere moisture.

  19. Soil-Vegetation-Atmosphere Radiative Transfer Model in Microwave Region

    Institute of Scientific and Technical Information of China (English)

    JIA Yuanyuan; LI Zhaoliang

    2008-01-01

    The radiative transfer is one of the significant theories that describe the processes of scattering,emission,and absorption of electromagnetic radiant intensity through scattering medium.It is the basis of the study on the quantitative remote sensing.In this paper,the radiative characteristics of soil,vegetation,and atmosphere were described respectively.The numerical solution of radiative transfer was accomplished by Successive Orders of Scattering (SOS).A radiative transfer model for simulating microwave brightness temperature over land surfaces was constructed,designed,and implemented.Analyzing the database generated from soil-vegetation-atmosphere radiative transfer model under Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) configuration showed that the atmospheric effects on microwave brightness temperature should not be neglected,particularly for higher frequency,and can be parameterized.At the same time,the relationship between the emissivities of the different channels was developed.The study results will promote the development of algorithm to retrieve geophysical parameters from microwave remotely sensed data.

  20. The Moisture Structure of ISO in Western North Pacific Revealed by AIRS

    Institute of Scientific and Technical Information of China (English)

    TAO Li; FU Xiouhua; WANG Bin

    2009-01-01

    Using the humidity profiles from the Atmospheric Infrared Sounder (AIRS) dataset, rainfall from the Tropical Rainfall Measuring Mission (TRMM) Global Precipitation Index (GPI), and surface winds from QuickSCAT (QSCAT) as well as SST from the Advanced Microwave Scanning Radiometer for NASA's Earth Observing System (AMSR_E), we analyzed the structure of summer intraseasonal oscillation (ISO) over the western North Pacific region in 2003-2004. We find that the signal of 20-90-day oscillations in the western North Pacific originates from the equatorial Indian Ocean, and propagates eastward to Philippine Sea and then moves northwestward to South China. The AIRS humidity data reveal that the boundary-layer moisture leads the mid-troposphere moisture during the ISO propagation. The positive SST anomaly may play an important role to moistening the boundary-layer, which preconditions the ISO propagation. Therefore, the intraseasonal SST anomaly could positively feed back to the atmosphere through moistening the boundary-layer, destabilizing the troposphere, and contributing to the northwestward propagation of the ISO in western North Pacific. On the other hand, the salient feature that the boundary-layer moisture anomaly leads mid-troposphere moisture does not exist in ECMWF/TOGA analysis.