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Sample records for amsr aqua amsr-e

  1. Ice Coverage, Aqua AMSR-E, 0.125 degrees, Global, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ice Coverage is measured by the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) onboard NASA's Aqua spacecraft.

  2. AMSR-E/Aqua Daily L3 6.25 km 89 GHz Brightness Temperature (Tb) Polar Grids V002

    Data.gov (United States)

    National Aeronautics and Space Administration — The AMSR-E/Aqua Level-3 6.25 km daily sea ice product includes 89.0 GHz brightness temperature averages (daily, ascending, and descending) on a 6.25 km polar...

  3. AMSR-E/Aqua Daily L3 25 km Tb and Sea Ice Concentration Polar Grids V002

    Data.gov (United States)

    National Aeronautics and Space Administration — The AMSR-E/Aqua Level-3 25 km daily sea ice product includes 6.9 - 89.0 GHz TBs and sea ice concentration averages (daily, ascending, and descending) on a 25 km...

  4. Toward advanced daily cloud-free snow cover and snow water equivalent products from Terra-Aqua MODIS and Aqua AMSR-E measurements

    Science.gov (United States)

    Gao, Yang; Xie, Hongjie; Lu, Ning; Yao, Tandong; Liang, Tiangang

    2010-05-01

    SummaryBy taking advantage of the high spatial resolution of optical sensors and cloud penetration of a passive microwave sensor, a method is developed to generate new daily cloud-free snow cover (SC) and snow water equivalent (SWE) products, both in 500 m spatial resolution, utilizing daily Terra-Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and Aqua Advanced Microwave Scanning Radiometer for NASA's Earth Observing System (AMSR-E) snow products. This method was tested in Fairbanks and Upper Susitna Valley, Alaska area for one hydrological year (October 2006-September 2007). The results confirm that daily MODIS products and Terra-Aqua MODIS combined products have similar and high classification accuracy (91-94%) in cloud-free conditions and that the daily combination can reduce cloud cover ˜10%. The results also show the snow accuracy of the new SC products is 86%, which is much higher than the 31%, 45%, and 49% of the Terra, Aqua, and Terra/Aqua combined snow cover products (in all weather conditions), respectively. The validation demonstrates that the accuracy of AMSR-E SWE products is 68.5% and they tend to overestimate SWE. Redistribution of SWE, based on sub-pixel analysis of AMSR-E pixels, not only generates the new product at higher spatial resolution, now more suitable for basin and regional monitoring and modeling, but also slightly increases the accuracy of the SWE estimations. This method can also be used in merging other optical data such as AVHRR, Landsat with passive microwave data such as SSMR, SSM/I, and for future NPP and NPOESS missions.

  5. 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 (NASDA)...

  6. 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 (NASDA)...

  7. AMSR-E-Based soil moisture retrieval algorithms and transferability to AMSR2

    Science.gov (United States)

    The launch of the Advanced Microwave Scanning Radiometer on NASA’s Earth Observing System Aqua satellite (AMSR-E) in June of 2002 has led to major advancements in the routine global mapping of soil moisture. The wide availability of AMSR-E data has promoted development of a number of global soil mo...

  8. 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...

  9. EOS Aqua AMSR-E Arctic Sea Ice Validation Program: Intercomparison Between Modeled and Measured Sea Ice Brightness Temperatures

    Science.gov (United States)

    Stroeve, J.; Markus, T.; Cavalieri, D. J.; Maslanik, J.; Sturm, M.; Henrichs, J.; Gasiewski, A.; Klein, M.

    2004-01-01

    During March 2003, an extensive field campaign was conducted near Barrow, Alaska to validate AQUA Advanced Microwave Scanning Radiometer (AMSR) sea ice products. Field, airborne and satellite data were collected over three different types of sea ice: 1) first year ice with little deformation, 2) first year ice with various amounts of deformation and 3) mixed first year ice and multi-year ice with various degrees of deformation. The validation plan relies primarily on comparisons between satellite, aircraft flights and ground-based measurements. Although these efforts are important, key aspects such as the effects of atmospheric conditions, snow properties, surface roughness, melt processes, etc on the sea ice algorithms are not sufficiently well understood or documented. To improve our understanding of these effects, we combined the detailed, in-situ data collection from the 2003 field campaign with radiance modeling using a radiative transfer model to simulate the top of the atmosphere AMSR brightness temperatures. This study reports on the results of the simulations for a variety of snow and ice types and compares the results with the National Oceanographic and Atmospheric Administration Environmental Technology Laboratory Polarimetric Scanning Radiometer (NOAA) (ETL) (PSR) microwave radiometer that was flown on the NASA P-3.

  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. Remote monitoring of soil moisture using passive microwave-based technologies – theoretical basic and overview of selected algorithms for AMSR-E

    Science.gov (United States)

    Satellite-based passive microwave remote sensing has been shown to be a valuable tool in mapping and monitoring global soil moisture. The Advanced Microwave Scanning Radiometer on the Aqua platform (AMSR-E) has made significant contributions to this application. As the result of agency and individua...

  13. Extracting Microwave Emissivity Characteristics over City using AMSR-E

    Science.gov (United States)

    Zhang, T.; Zhang, L.; Jiang, L.; Li, Y.

    2010-12-01

    The spectrums of different land types are very important in the application of remote sensing. Different spectrums of different land types can be used in surface classification, change detection, and so on. The microwave emissivity over land is the foundation of land parameters retrieval using passive microwave remote sensing. It depends on land type due to different objects’ structure, moisture and roughness on the earth. It has shown that the land surface microwave emissivity contributed to atmosphere temperature and moisture retrieval. Meanwhile, it depends on land type, vegetation cover, and moisture et al.. There are many researches on microwave emissivity of various land types, such as bare soil, vegetation, snow, but city was less mentioned [1]. However, with the development of society, the process of urbanization accelerated quickly. The area of city expanded fast and the fraction of city area increased in one microwave pixel, especially in The North China Plain (about 30%). The passive microwave pixel containing city has impact on satellite observation and surface parameters retrieval then. So it is essential to study the emissivity of city in order to improve the accuracy of land surface parameters retrieval from passive microwave remote sensing. To study the microwave emissivity of city, some ‘pure’ city pixels were selected according to IGBP classification data, which was defined the fraction cover of city is larger than 85%. The city emissivity was calculated using AMSR-E L2A brightness temperature and GLDAS land surface temperature data at different frequencies and polarizations over 2008 in China. Then the seasonal variation was analyzed along the year. Finally, the characteristic of city emissivity were compared with some meteorological data, seeking the relationship between city emissivity and climatic factors. The results have shown that the emissivity of city was different for different frequencies. It increased with the frequency becoming

  14. 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...

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. Combining MODIS and AMSR-E-based vegetation moisture retrievals for improved fire risk monitoring

    Science.gov (United States)

    Dasgupta, Swarvanu; Qu, John J.

    2006-08-01

    Research has shown that remote sensing in both the optical and microwave domain has the capability of estimating vegetation water content (VWC). Though lower in spatial resolution than MODIS optical bands, AMSR-E microwave measurements are typically less affected by clouds, water vapor, aerosol or solar illumination, making them complementary to MODIS real time measurements over regions of clouds and haze. In this study we explored a wavelet based approach for combining vegetation water content observations derived from higher spatial resolution MODIS and lower spatial resolution AMSR-E microwave measurements. Regression analysis between AMSR-E VWC and spatially aggregated MODIS NDII (Normalized Difference Infrared Index) was first used to scale MODIS NDII to MODIS VWC products. Our approach for combining information from the two sensors resorts to multiresolution wavelet decomposition of MODIS VWC into a set of detail images and a single approximation image at AMSR-E resolution. The substitution method of image fusion is then undertaken, in which the approximation image is replaced by AMSR-E VWC image, prior to using inverse wavelet transform to construct a merged VWC product. The merged VWC product thus has information from both MODIS and AMSR-E measurements. The technique is applied over low vegetation regions in Texas grasslands to obtain merged VWC products at intermediate resolutions of ~1.5km. Apart from offering a way to calibrate MODIS VWC content products to AMSR-E observations, the technique has the potential for downscaling AMSR-E VWC to higher spatial resolution over moderately cloudy or hazy regions where MODIS reflective bands become contaminated by the atmosphere. During such situations when contaminated MODIS signals cannot be used to obtain the wavelet detail images, MODIS detail images from a preceding time step is used to downscale the current AMSR-E VWC to higher resolutions. This approach of using detail images from the recent past would be

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    J. Röhrs

    2012-03-01

    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 wider than 3 km in the entire Arctic Ocean. The algorithm detects 50 % of the lead area that was visible in optical MODIS satellite images. Passive microwave imagery from the Advanced Microwave Scanning Radiometer – Earth Observation System (AMSR-E is used, allowing daily observations due to the fact that AMSR-E does not depend on daylight or cloud conditions. Using the unique signatures of thin ice in the brightness temperature ratio between the 89 GHz and 19 GHz channels, the algorithm is able to detect thin ice areas in the ice cover and is optimized to detect leads. Leads are mapped for the period from 2002 to 2011 excluding the summer months, and validated qualitatively by using MODIS, Envisat ASAR, and CryoSat-2 data. Several frequently recurring large scale lead patterns are found, especially in regions where sea ice is known to drift out of the Arctic Ocean.

  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. Applications of AMSR-E Measurements for Tropical Cyclone Predictions Part Ⅰ: Retrieval of Sea Surface Temperature and Wind Speed

    Institute of Scientific and Technical Information of China (English)

    Banghua YAN; Fuzhong WENG

    2008-01-01

    Existing satellite microwave algorithms for retrieving Sea Surface Temperature(Sst)and wind(SSW)are applicable primarily for non-raining cloudy conditions.With the launch of the Earth Observing System (EOS)Aqua satellite in 2002,the Advanced Microwave Scanning Radiometer(AMSR-E)onboard provides some unique measurements at lower frequencies which are sensitive to ocean surface parameters under ad-verse weather conditions.In this study,a new algorithm is developed to derive SST and SSW for hurricane predictions such as hurricane vortex analysis from the AMSR-E measurements at 6.925 and 10.65 GHz.In the algorithm,the effects of precipitation emission and scattering on the measurements are properly taken into account.The algorithm performances are evaluated with buoy measurements and aircraft dropsonde data.It is found that the root mean square (RMS) errors for SST and SSW are about 1.8K and 1.9m s(-1),respectively,when the results are compared with the buoy data over open oceans under precipitating clouds (e.g.,its liquid water path is larger than 0.5 mm),while they are 1.1 K for SST and 2.0 ms(-1)for SSW,respectively,when the retrievals are validated against the dropsonde measurements over warm oceans.These results indicate that our newly developed algorithm catl provide some critical surface information for trop-ical cycle predictions.Currently,this newly developed algorithm has been implemented into the hybrid variational scheme for the hurricane vortex analysis to provide predictions of SST and SSW fields.

  7. A blending snow cover data base on MODIS and AMSR-E snow cover in Qinghai-Tibet Plateau

    Science.gov (United States)

    Xiaohua, H.; Wang, J.; Che, T.; Dai, L. Y.

    2012-04-01

    The algorithms of MODIS Terra and MODIS Aqua versions of the snow products have been developed by the NASA National Snow and Ice Data Center (NSIDC). The MODIS global snow-cover products have been available through the NSIDC Distributed Active Archive Center (DAAC) since February 24, 2000 to Terra and July 4, 2002 to Aqua. The MODIS snow-cover maps represent a potential improvement relative to hemispheric-scale snow maps that are available today mainly because of the improved spatial resolution and snow/cloud discrimination capabilities of MODIS, and the frequent global coverage. In China, the snow distribution is different to other regions. Their accuracy on Qinghai-Tibet Plateau (QTP), however, has not yet been established. There are some drawbacks about NSIDC global snow cover products on QTP: 1. The characteristics of snow depth distribution on QTP: Thin, discontinuous. Our research indicated the MODIS snow-cover products underestimated the snow cover area in QTP. 2. The daily snow cover product from MODIS-Terra and Aqua can include the data gaps. 3. The snow products can separate snow from most obscuring clouds. However, there are still many cloud pixels in daily snow cover products. The study developed a new blending daily snow cover algorithm through improving the NSIDC snow algorithms and combining MODIS and AMSR-E data in QTP. The new snow cover products will provide daily snow cover at 500-m resolution in QTP. The new snow cover algorithm employs a grouped-criteria technique using the Normalized Difference Snow Index (NDSI) and other spectral threshold tests and image fusion technology to identify and classify snow on a pixel-by-pixel basis. The usefulness of the NDSI is based on the fact that snow and ice are considerably more reflective in the visible than in the shortwave IR part of the spectrum, and the reflectance of most clouds remains high in the short-wave IR, while the reflectance of snow is low. We propose a set of three steps, based on a

  8. A Round Robin evaluation of AMSR-E soil moisture retrievals

    Science.gov (United States)

    Mittelbach, Heidi; Hirschi, Martin; Nicolai-Shaw, Nadine; Gruber, Alexander; Dorigo, Wouter; de Jeu, Richard; Parinussa, Robert; Jones, Lucas A.; Wagner, Wolfgang; Seneviratne, Sonia I.

    2014-05-01

    Large-scale and long-term soil moisture observations based on remote sensing are promising data sets to investigate and understand various processes of the climate system including the water and biochemical cycles. Currently, the ESA Climate Change Initiative for soil moisture develops and evaluates a consistent global long-term soil moisture data set, which is based on merging passive and active remotely sensed soil moisture. Within this project an inter-comparison of algorithms for AMSR-E and ASCAT Level 2 products was conducted separately to assess the performance of different retrieval algorithms. Here we present the inter-comparison of AMSR-E Level 2 soil moisture products. These include the public data sets from University of Montana (UMT), Japan Aerospace and Space Exploration Agency (JAXA), VU University of Amsterdam (VUA; two algorithms) and National Aeronautics and Space Administration (NASA). All participating algorithms are applied to the same AMSR-E Level 1 data set. Ascending and descending paths of scaled surface soil moisture are considered and evaluated separately in daily and monthly resolution over the 2007-2011 time period. Absolute values of soil moisture as well as their long-term anomalies (i.e. removing the mean seasonal cycle) and short-term anomalies (i.e. removing a five weeks moving average) are evaluated. The evaluation is based on conventional measures like correlation and unbiased root-mean-square differences as well as on the application of the triple collocation method. As reference data set, surface soil moisture of 75 quality controlled soil moisture sites from the International Soil Moisture Network (ISMN) are used, which cover a wide range of vegetation density and climate conditions. For the application of the triple collocation method, surface soil moisture estimates from the Global Land Data Assimilation System are used as third independent data set. We find that the participating algorithms generally display a better

  9. 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

  10. Estimation of melt pond fraction over high-concentration Arctic sea ice using AMSR-E passive microwave data

    Science.gov (United States)

    Tanaka, Yasuhiro; Tateyama, Kazutaka; Kameda, Takao; Hutchings, Jennifer K.

    2016-09-01

    Melt pond fraction (MPF) on sea ice is an important factor for ice-albedo feedback throughout the Arctic Ocean. We propose an algorithm to estimate MPF using satellite passive microwave data in this study. The brightness temperature (TB) data obtained from the Advanced Microwave Scanning Radiometer-Earth observing system (AMSR-E) were compared to the ship-based MPF in the Beaufort Sea and Canadian Arctic Archipelago. The difference between the TB at horizontal and vertical polarizations of 6.9 and 89.0 GHz (MP06H-89V), respectively, depends on the MPF. The correlation between MP06H-89V and ship-based MPF was higher than that between ship-based MPF and two individual channels (6.9 and 89.0 GHz of horizontal and vertical polarizations, respectively). The MPF determined with the highest resolution channel, 89.0 GHz (5 km × 5 km), provides spatial information with more detail than the 6.9 GHz channel. The algorithm estimates the relative fraction of ice covered by water (1) over areas where sea ice concentration is higher than 95%, (2) during late summer, and (3) in areas with low atmospheric humidity. The MPF estimated from AMSR-E data (AMSR-E MPF) in early summer was underestimated at lower latitudes and overestimated at higher latitudes, compared to the MPF obtained from the Moderate Resolution Image Spectrometer (MODIS MPF). The differences between AMSR-E MPF and MODIS MPF were less than 5% in most the regions and the periods. Our results suggest that the proposal algorithm serves as a basis for building time series of MPF in regions of consolidated ice pack.

  11. 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.

  12. 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.

  13. Large Scale Evaluation of AMSR-E Soil Moisture Products Based on Ground Soil Moisture Network Measurements

    Science.gov (United States)

    Gruhier, C.; de Rosnay, P.; Richaume, P.; Kerr, Y.; Rudiger, C.; Boulet, G.; Walker, J. P.; Mougin, E.; Ceschia, E.; Calvet, J.

    2007-05-01

    This paper presents an evaluation of AMSR-E (Advanced Microwave Scanning Radiometer for EOS) soil moisture products, based on a comparison with three ground soil moisture networks. The selected ground sites are representative of various climatic, hydrologic and environmental conditions in temperate and semi-arid areas. They are located in the south-west of France, south-east of Australia and the Gourma region of the Sahel. These sites were respectively implemented in the framework of the projects SMOSREX (Surface Monitoring Of Soil Reservoir Experiment), SASMAS/GoREx (Scaling and Assimilation of Soil Moisture and Streamflow in the Goulburn River Experimental catchment) and AMMA (African Monsoon Multidisciplinary Analysis). In all cases, the arrangement of the soil moisture measuring sites was specifically designed to address the validation of remotely sensed soil moisture in the context of the preparation of the SMOS (Soil Moisture and Ocean Salinity) project. For the purpose of this study, 25km AMSR-E products were used, including brightness temperatures at 6.9 and 10.7 GHz, and derived soil moisture. The study is focused on the year 2005. It is based on ground soil moisture network measurements from 4 stations for SMOSREX extended to the SUDOUEST project of CESBIO, 12 stations for GoRex, and 4 stations for AMMA. Temporal and spatial features of soil moisture variability and stability is a critical issue to be addressed for remotely sensed soil moisture validation. While ground measurements provide information on soil moisture dynamics at local scale and high temporal resolution (hourly), satellite measurements are sparser in time (up to several days), but cover a larger region (25km x 25km for AMSR-E). First, a statistical analysis, including mean relative difference and Spearman rank, is conducted for the three soil moisture networks. This method is mainly based on the approach proposed by Cosh et al. (2004) for the purpose of the use of ground networks for

  14. 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.

  15. 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....

  16. Performance of AMSR_E soil moisture data assimilation in CLM4.5 model for monitoring hydrologic fluxes at global scale

    Science.gov (United States)

    Liu, Di; Mishra, Ashok K.

    2017-04-01

    In this study, we evaluated the performance of community land surface model (CLM4.5) to simulate the hydrologic fluxes, such as, soil moisture (SM), evapotranspiration (ET) and runoff with (without) remote sensing data assimilation. The Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR_E) daily SM (both ascending and descending) are incorporated into the CLM4.5 model using data assimilation (DA) technique. The GLDAS data is used to validate the AMSR_E SM data and evaluate the performance of CLM4.5 simulations. The AMSR_E SM data are rescaled to meet the resolution of CLM4.5 model. By assimilating the AMSR_E SM data into the CLM4.5 model can improve the SM simulations, especially over the climate transition zones in Africa, East Australia, South South America, Southeast Asia, and East North America in summer season. The Local Ensemble Kalman Filter (LEnKF) technique improves the performance of CLM4.5 model compared to the directly substituted method. The improvement in ET and surface runoff simulations from CLM4.5 model assimilated with AMSR_E SM data shares similar spatial patterns with SM.

  17. 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)

  18. Estimation de la superficie du couvert nival a partir d'une combinaison des donnees de teledetection MODIS et AMSR-E dans un contexte de prevision des crues printanieres au Quebec

    Science.gov (United States)

    Bergeron, Jean

    Snow cover estimation is a principal source of error for spring streamflow simulations in Québec, Canada. Optical and near infrared remote sensing can improve snow cover area (SCA) estimation due to high spatial resolution but is limited by cloud cover and incoming solar radiation. Passive microwave remote sensing is complementary by its near-transparence to cloud cover and independence to incoming solar radiation, but is limited by its coarse spatial resolution. The study aims to create an improved SCA product from blended passive microwave (AMSR-E daily L3 Brightness Temperature) and optical (MODIS Terra and Aqua daily snow cover L3) remote sensing data in order to improve estimation of river streamflow caused by snowmelt with Québec's operational MOHYSE hydrological model through direct-insertion of the blended SCA product in a coupled snowmelt module (SPH-AV). SCA estimated from AMSR-E data is first compared with SCA estimated with MODIS, as well as with in situ snow depth measurements. Results show good agreement (+95%) between AMSR-E-derived and MODIS-derived SCA products in spring but comparisons with Environment Canada ground stations and SCA derived from Advanced Very High Resolution Radiometer (AVHRR) data show lesser agreements (83 % and 74% respectively). Results also show that AMSR-E generally underestimates SCA. Assimilating the blended snow product in SPH-AV coupled with MOHYSE yields significant improvement of simulated streamflow for the aux Écorces et au Saumon rivers overall when compared with simulations with no update during thaw events, These improvements are similar to results driven by biweekly ground data. Assimilation of remotely-sensed passive microwave data was also found to have little positive impact on springflood forecast due to the difficulty in differentiating melting snow from snow-free surfaces. Considering the direct-insertion and Newtonian nudging assimilation methods, the study also shows the latter method to be superior to

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. Estimating ice phenology on large northern lakes from AMSR-E: algorithm development and application to Great Bear Lake and Great Slave Lake, Canada

    Directory of Open Access Journals (Sweden)

    K.-K. Kang

    2011-11-01

    Full Text Available Time series of brightness temperatures (TB from the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E are examined to determine ice phenological parameters on the two largest lakes of northern Canada: Great Bear Lake (GBL and Great Slave Lake (GSL. TB measurements from the 18.7, 23.8, 36.5, and 89.0 GHz channels (H- and V- polarization are compared to assess their potential for detecting freeze-onset/melt-onset and ice-on/ice-off dates on both lakes. The 18.7 GHz (H-pol channel is found to be the most suitable for estimating these ice dates as well as the duration of the ice cover and ice-free seasons. A new algorithm is proposed using this channel and applied to map all ice phenological parameters on GBL and GSL over seven ice seasons (2002–2009. Analysis of the spatio-temporal patterns of each parameter at the pixel level reveals that: (1 both freeze-onset and ice-on dates occur on average about one week earlier on GBL than on GSL (Day of Year (DY 318 and 333 for GBL; DY 328 and 343 for GSL; (2 the freeze-up process or freeze duration (freeze-onset to ice-on takes a slightly longer amount of time on GBL than on GSL (about 1 week on average; (3 melt-onset and ice-off dates occur on average one week and approximately four weeks later, respectively, on GBL (DY 143 and 183 for GBL; DY 135 and 157 for GSL; (4 the break-up process or melt duration (melt-onset to ice-off lasts on average about three weeks longer on GBL; and (5 ice cover duration estimated from each individual pixel is on average about three weeks longer on GBL compared to its more southern counterpart, GSL. A cross-comparison of dates for several ice phenological parameters derived from other satellite remote sensing products (e.g. NOAA Interactive Multisensor Snow and Ice Mapping System (IMS, QuikSCAT, and Canadian Ice Service Database show that, despite its relatively coarse spatial resolution, AMSR-E 18.7 GHz provides a

  4. Estimating ice phenology on large northern lakes from AMSR-E: algorithm development and application to Great Bear Lake and Great Slave Lake, Canada

    Directory of Open Access Journals (Sweden)

    K.-K. Kang

    2012-03-01

    Full Text Available Time series of brightness temperatures (TB from the Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E are examined to determine ice phenology variables on the two largest lakes of northern Canada: Great Bear Lake (GBL and Great Slave Lake (GSL. TB measurements from the 18.7, 23.8, 36.5, and 89.0 GHz channels (H- and V- polarization are compared to assess their potential for detecting freeze-onset/melt-onset and ice-on/ice-off dates on both lakes. The 18.7 GHz (H-pol channel is found to be the most suitable for estimating these ice dates as well as the duration of the ice cover and ice-free seasons. A new algorithm is proposed using this channel and applied to map all ice phenology variables on GBL and GSL over seven ice seasons (2002–2009. Analysis of the spatio-temporal patterns of each variable at the pixel level reveals that: (1 both freeze-onset and ice-on dates occur on average about one week earlier on GBL than on GSL (Day of Year (DY 318 and 333 for GBL; DY 328 and 343 for GSL; (2 the freeze-up process or freeze duration (freeze-onset to ice-on takes a slightly longer amount of time on GBL than on GSL (about 1 week on average; (3 melt-onset and ice-off dates occur on average one week and approximately four weeks later, respectively, on GBL (DY 143 and 183 for GBL; DY 135 and 157 for GSL; (4 the break-up process or melt duration (melt-onset to ice-off lasts on average about three weeks longer on GBL; and (5 ice cover duration estimated from each individual pixel is on average about three weeks longer on GBL compared to its more southern counterpart, GSL. A comparison of dates for several ice phenology variables derived from other satellite remote sensing products (e.g. NOAA Interactive Multisensor Snow and Ice Mapping System (IMS, QuikSCAT, and Canadian Ice Service Database show that, despite its relatively coarse spatial resolution, AMSR-E 18.7 GHz provides a viable means for

  5. 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.

  6. 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.

  7. 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....

  8. Semi-empirical Model for Retrieving Land Surface Temperature Based on AMSR-E Data%一种基于AMSR-E的地表温度半经验反演模型

    Institute of Scientific and Technical Information of China (English)

    陈修治; 李勇; 韩留生; 苏泳娴; 陈水森

    2013-01-01

    This paper develops a semi-empirical model for retrieving land surface temperature ( sT ) using AMSR-E data based on the passive microwave radiative transfer equation, in combination with the relation between vegetation depth and MPDI, and that between precipitable water content and land surface temperature. With this model, sT can be easily simulated from the brightness temperatures of AMSR-E 6.9GHz band and 10.7GHz band without any ancillary data. The sT mapping and validation results of China in 2009 prove that the average sT retrieval accuracy reaches about 2.51 (R℃ 2=0.79). It can be considered that the model is a simple and also effective algorithm to retrieve sT with passive microwave remote sensing data.%  基于被动微波辐射传输方程,结合De Jeu建立的透过率与微波极化差异指数的通用关系式,以及Smiths建立的地表温度与大气总可降水量的经验关系,构建了一套基于AMSR-E影像的地表温度半经验反演模型,该模型无需借助其他辅助数据,便可从AMSR-E 6.9GHz和10.7GHz两个波段的亮度温度模拟得到地表温度变量。对2009年我国地表温度进行实例模拟和验证,结果显示,该地表温度模型的平均反演精度达到2.54℃(R2=0.79),是一种简单有效的被动微波遥感地表温度模拟方法。

  9. Using machine learning to produce near surface soil moisture estimates from deeper in situ records at U.S. Climate Reference Network (USCRN) locations: Analysis and applications to AMSR-E satellite validation

    Science.gov (United States)

    Coopersmith, Evan J.; Cosh, Michael H.; Bell, Jesse E.; Boyles, Ryan

    2016-12-01

    Surface soil moisture is a critical parameter for understanding the energy flux at the land atmosphere boundary. Weather modeling, climate prediction, and remote sensing validation are some of the applications for surface soil moisture information. The most common in situ measurement for these purposes are sensors that are installed at depths of approximately 5 cm. There are however, sensor technologies and network designs that do not provide an estimate at this depth. If soil moisture estimates at deeper depths could be extrapolated to the near surface, in situ networks providing estimates at other depths would see their values enhanced. Soil moisture sensors from the U.S. Climate Reference Network (USCRN) were used to generate models of 5 cm soil moisture, with 10 cm soil moisture measurements and antecedent precipitation as inputs, via machine learning techniques. Validation was conducted with the available, in situ, 5 cm resources. It was shown that a 5 cm estimate, which was extrapolated from a 10 cm sensor and antecedent local precipitation, produced a root-mean-squared-error (RMSE) of 0.0215 m3/m3. Next, these machine-learning-generated 5 cm estimates were also compared to AMSR-E estimates at these locations. These results were then compared with the performance of the actual in situ readings against the AMSR-E data. The machine learning estimates at 5 cm produced an RMSE of approximately 0.03 m3/m3 when an optimized gain and offset were applied. This is necessary considering the performance of AMSR-E in locations characterized by high vegetation water contents, which are present across North Carolina. Lastly, the application of this extrapolation technique is applied to the ECONet in North Carolina, which provides a 10 cm depth measurement as its shallowest soil moisture estimate. A raw RMSE of 0.028 m3/m3 was achieved, and with a linear gain and offset applied at each ECONet site, an RMSE of 0.013 m3/m3 was possible.

  10. 改进AMSR-E雪水当量算法研究%On Improvement of Snow Water Equivalence Estimation for Passive Microwave Instrument-AMSR/E

    Institute of Scientific and Technical Information of China (English)

    蒋玲梅; 施建成; 张立新

    2007-01-01

    为了发展雪水当量物理反演算法,本文对不同散射阶模型--零阶、一阶、多次散射模型进行敏感性试验与分析,结果表明我们必须在前向理论模型和反演模型中考虑多次散射作用.本文采用的多次散射积雪辐射理论模型--双矩阵法(Matrix Doubling)求解辐射传输方程,用致密介质理论模型(DMRT)模拟积雪发射和消光特性,用AIEM模型模拟地表辐射及作为辐射传输方程的边界条件.由于该多次散射积雪辐射理论模型的复杂性,拟发展出简单且高精度的积雪辐射参数化模型,以发展雪水当量物理反演算法.因此,在包括多次散射的积雪理论模型基础上,本文通过建立针对AMSR-E传感器参数设置的积雪辐射模拟数据库,该数据库包含了各种可能的自然积雪和地表特性参数.从而在模拟数据库基础上,本文发展了针对AMSR-E的积雪参数化模型.%In this paper, we evaluate the capability of a multi-scattering microwave emission model that includes the Dense Media Radiative Transfer Model(DMRT) and Advanced Integral Equation Model(AIEM) to simulate dry snow emission with the Matrix Doubling approach. We compared the predictions of this model with ground experimental measurements. The comparison showed that our snow microwave emission model agreed well with the experimental measurements. In order to develop retrieval snow properties: snow depth or snow water equivalence(SWE) retrieval algorithm, we carried out the sensitivity test between the emission models with the different scattering-order: the zeroth-order, the first-order and the multi-scattering models. The results indicated that the multi-scattering effects have to be taken into account in the snow emission model, especially for large grain size. Due to the complexity of the multi-scattering model, we developed a parameterized inversion model using our multi-scattering emission model with a wide range of snow and under

  11. Assessment of AMSR-E Sea Ice Concentration Products at Ice Edges in Antarctic%南极海冰边界AMSR-E密集度产品精度检验

    Institute of Scientific and Technical Information of China (English)

    苏昊月; 庞小平; 赵羲

    2016-01-01

    根据海冰船测目视观测标准在MODIS影像上提取模拟的海冰边界,并利用相应的MODIS海冰密集度验证AMSR-E海冰密集度产品在海冰边界的精度.研究结果表明,海冰边界像素上,AMSR-E海冰密集度的平均值与15%阈值存在显著差异,且AMSR-E与MODIS海冰密集度的相关性很弱(R2≤0.2),基于ASI的海冰反演算法在夏季低估边界海冰密集度.考虑整个冰区(包括多年冰、一年冰、新冰和开阔海域)的截线分析显示,AMSR-E与MODIS海冰密集度存在较好的线性关系(夏季R2=0.82,冬季R2=0.81),AMSR-E海冰密集度在20%~30%区间的误差最大.

  12. The Arctic Sea Ice Refractive Index Retrieval Based on Satellite AMSR-E Observations%基于星载辐射计AMSR-E不同波段的北极海冰折射系数提取

    Institute of Scientific and Technical Information of China (English)

    陈瀚阅; 毕海波; 牛铮

    2012-01-01

    The refractive index of sea ice in the polar region is an important geophysical parameter. It is needed as a vital input for some numerical climate models and is helpful to classifying sea ice types. In the present study, according to Hong Approximation (HA) , we retrieved the arctic sea ice refractive index at 6. 9, 10. 7, 23, 37, and 89 GHz in different arctic climatological conditions. The refractive indices of wintertime first year (FY) sea ice and summertime ice were derived with average values of 1. 78~1. 75 and 1. 724~L. 70 at different frequencies respectively, which are consistent with previous studies. However, for multiyear (MY) ice, the results indicated relatively large bias between modeled results since 10. 7 GHz. At a higher frequency, there is larger MY ice refractive index difference. This bias is mainly attributed to the volume scattering effect on MY microwave radiation due to emergence of massive small empty cavities after the brine water in MY ice is discharged into sea. In addition, the -retrieved sea ice refractive indices can be utilized to classify ice types (for example, the winter derivation at 89 GHz), to identify coastal polynyas (winter retrieval at 6. 9 GHz), and to outline the areal extent of significantly melting marginal sea ice zone (MIZ) (summer result at 6. 9 GHz). The investigation of this study suggests an effective tool of passive microwave remote sensing in monitoring sea ice refractive index variability.%海冰折射系数是一个重要的地球物理参数.利用Hong Approximation(HA)算法和星载辐射计AMSR-E数据,基于不同微波频段(6.9,10.7,23,37,89 GHz)实现北极地区不同季节海冰折射系数反演.首先对反演所用关键数据海冰密集度反演算法的系点进行优化,反演结果与验证数据平均偏差分别为3.00%和-0.50%,低于其它常用算法.结果表明:冬季一年冰和夏季海冰的折射系数反演结果在所有微波频段的平均值范围为(1.78~1.75)和(1

  13. Current status of the global change observation mission - water SHIZUKU (GCOM-W) and the advanced microwave scanning radiometer 2 (AMSR2) (Conference Presentation)

    Science.gov (United States)

    Maeda, Takashi; Kachi, Misako; Kasahara, Marehito

    2016-10-01

    Japan Aerospace Exploration Agency (JAXA) launched the Global Change Observation Mission - Water (GCOM-W) or "SHIZUKU" in 18 May 2012 (JST) from JAXA's Tanegashima Space Center. The GCOM-W satellite joins to NASA's A-train orbit since June 2012, and its observation is ongoing. The GCOM-W satellite carries the Advanced Microwave Scanning Radiometer 2 (AMSR2). The AMSR2 is a multi-frequency, total-power microwave radiometer system with dual polarization channels for all frequency bands, and successor microwave radiometer to the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) loaded on the NASA's Aqua satellite. The AMSR-E kept observation in the slower rotation speed (2 rotations per minute) for cross-calibration with AMSR2 since December 2012, its operation ended in December 2015. The AMSR2 is designed almost similarly as the AMSR-E. The AMSR2 has a conical scanning system with large-size offset parabolic antenna, a feed horn cluster to realize multi-frequency observation, and an external calibration system with two temperature standards. However, some important improvements are made. For example, the main reflector size of the AMSR2 is expanded to 2.0 m to observe the Earth's surface in higher spatial resolution, and 7.3-GHz channel is newly added to detect radio frequency interferences at 6.9 GHz. In this paper, we present a recent topic for the AMSR2 (i.e., RFI detection performances) and the current operation status of the AMSR2.

  14. Snow and Ice Products from the Aqua, Terra, and ICESat Satellites at the National Snow and Ice Data Center

    Science.gov (United States)

    Meier, W. N.; Marquis, M.; Kaminski, M.; Armstrong, R.; Brodzik, M.

    2004-05-01

    The National Snow and Ice Data Center (NSIDC) at the University of Colorado, Boulder - one of eight NASA Distributed Active Archive Centers (DAACs) - archives and distributes several products from sensors on the suite of NASA Earth Observing System (EOS) satellites. These include the sun-synchronous polar-orbiting Aqua (launched 4 May 2002) and Terra (launched 18 December 1999) platforms and the Ice, Cloud, and land Elevation Satellite (ICESat) (launched 12 January 2003). The Advanced Microwave Scanning Radiometer-EOS (AMSR-E) is a multi-channel passive microwave radiometer on Aqua (http://nsidc.org/daac/amsr/). AMSR-E Level 3 snow products are produced in EASE-Grid format for both the Northern and Southern Hemisphere and are available as daily, 5-day, and monthly fields. Daily AMSR-E Level 3 sea ice products are produced on a polar stereographic projection at gridded spatial resolutions of 6.25 km, 12.5 km and 25 km. Since April 2004, these products have been available for public distribution from NSIDC. The Moderate-resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua is a 36-channel visible/infrared sensor that produces a consistent long-term time series of fully-automated, quality-controlled data. Level 2 swath products are available for both snow cover and sea ice. Daily and 8-day Level 3 gridded snow cover products are available with estimates of snow extent and albedo at 500m resolution, along with daily Level 3 gridded sea ice products with estimates for sea ice extent and ice surface temperature at 1 km resolution. These products are currently available from NSIDC (http://nsidc.org/daac/modis/). The Geoscience Laser Altimeter System (GLAS) is the sole instrument on ICESat. The standard GLAS Level 2 ice sheet altimetry product contains the ice sheet elevation and elevation distribution calculated from algorithms fine-tuned for ice sheet returns. The standard GLAS Level 2 sea ice altimetry product contains the sea ice freeboard and sea ice

  15. 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.

  16. 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...

  17. 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, or...

  18. 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, or...

  19. [The arctic sea ice refractive index retrieval based on satellite AMSR-E observations].

    Science.gov (United States)

    Chen, Han-Yue; Bi, Hai-Bo; Niu, Zheng

    2012-11-01

    The refractive index of sea ice in the polar region is an important geophysical parameter. It is needed as a vital input for some numerical climate models and is helpful to classifying sea ice types. In the present study, according to Hong Approximation (HA), we retrieved the arctic sea ice refractive index at 6.9, 10.7, 23, 37, and 89 GHz in different arctic climatological conditions. The refractive indices of wintertime first year (FY) sea ice and summertime ice were derived with average values of 1.78 - 1.75 and 1.724 - 1.70 at different frequencies respectively, which are consistent with previous studies. However, for multiyear (MY) ice, the results indicated relatively large bias between modeled results since 10.7 GHz. At a higher frequency, there is larger MY ice refractive index difference. This bias is mainly attributed to the volume scattering effect on MY microwave radiation due to emergence of massive small empty cavities after the brine water in MY ice is discharged into sea. In addition, the retrieved sea ice refractive indices can be utilized to classify ice types (for example, the winter derivation at 89 GHz), to identify coastal polynyas (winter retrieval at 6.9 GHz), and to outline the areal extent of significantly melting marginal sea ice zone (MIZ) (summer result at 6.9 GHz). The investigation of this study suggests an effective tool of passive microwave remote sensing in monitoring sea ice refractive index variability.

  20. Landslide susceptibility mapping using downscaled AMSR-E soil moisture: A case study from Cleveland Corral, California, US

    Science.gov (United States)

    As soil moisture increases, slope stability decreases. Remotely sensed soil moisture data can provide routine updates of slope conditions necessary for landslide predictions. For regional scale landslide investigations, only remote sensing methods have the spatial and temporal resolution required to...

  1. Evaluation of the Surface Water Distribution in North-Central Namibia Based on MODIS and AMSR Series

    Directory of Open Access Journals (Sweden)

    Hiroki Mizuochi

    2014-08-01

    Full Text Available Semi-arid North-central Namibia has high potential for rice cultivation because large seasonal wetlands (oshana form during the rainy season. Evaluating the distribution of surface water would reveal the area potentially suitable for rice cultivation. In this study, we detected the distribution of surface water with high spatial and temporal resolution by using two types of complementary satellite data: MODIS (MODerate-resolution Imaging Spectroradiometer and AMSR-E (Advanced Microwave Scanning Radiometer–Earth Observing System, using AMSR2 after AMSR-E became unavailable. We combined the modified normalized-difference water index (MNDWI from the MODIS data with the normalized-difference polarization index (NDPI from the AMSR-E and AMSR2 data to determine the area of surface water. We developed a simple gap-filling method (“database unmixing” with the two indices, thereby providing daily 500-m-resolution MNDWI maps of north-central Namibia regardless of whether the sky was clear. Moreover, through receiver-operator characteristics (ROC analysis, we determined the threshold MNDWI (−0.316 for wetlands. Using ROC analysis, MNDWI had moderate performance (the area under the ROC curve was 0.747, and the recognition error for seasonal wetlands and dry land was 21.2%. The threshold MNDWI let us calculate probability of water presence (PWP maps for the rainy season and the whole year. The PWP maps revealed the total area potentially suitable for rice cultivation: 1255 km2 (1.6% of the study area.

  2. Assessment of Cryospheric Products Derived from Microwave Sensors Using the MiRS Algorithm with Applications to GCOM-W/AMSR2

    Science.gov (United States)

    Grassotti, C.; Boukabara, S. A.; Garrett, K.; Islam, T.; Zubko, V.; Zhan, X.; Mims, A.

    2013-12-01

    The Microwave Integrated Retrieval System (MiRS) has been the NOAA official operational microwave retrieval algorithm since 2007 and is currently run operationally on microwave data from NOAA, Metop, DMSP and Suomi-NPP polar orbiting satellites. Work is underway to extend MiRS to Megha-Tropics/SAPHIR data by 2014. It has also been run experimentally on data from TRMM/TMI, Aqua/AMSR-E. The inversion within MiRS follows a 1D-variational methodology, in which the fundamental physical attributes affecting the microwave observations are retrieved physically, including the profile of atmospheric temperature, water vapor, hydrometeors, as well as surface emissivity and temperature. The community radiative transfer model (CRTM) is used as the forward and Jacobian operator to simulate the radiances at each iteration prior to fitting the measurements to within the noise level. The retrieved surface properties are then used to determine surface physical characteristics, including, when appropriate, cryospheric parameters such as sea ice concentration, ice age, and snow water amount, using pre-determined relationships that link emissivity and effective skin temperature to these parameters. These links are based, in part, on physical modeling of snow and ice radiative properties. The determination of the cryospheric properties from the core retrieved products uses a constrained search within a sensor-specific pre-computed catalog which relates the emissivities at surface-sensitive channels to the cryospheric parameters of interest. In this study, we will present an overview of results to date in applying MiRS to a number of sensors, including AMSR2, and, where possible, evaluate performances with collocated independent observations.

  3. 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%.

  4. 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...

  5. 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.

  6. Soil moisture retrieval at regional scale from AMSR2 data (Conference Presentation)

    Science.gov (United States)

    Paloscia, Simonetta; Santi, Emanuele; Pettinato, Simone; Brocca, Luca; Ciabatta, Luca

    2016-10-01

    The aim of this work is to exploit the potential of AMSR2 for hydrological applications on a regional scale and in heterogeneous environments characterised by different surface covers at subpixel resolution. The soil moisture content (SMC) estimated from Advanced Microwave Scanning Radiometer 2 (AMSR2) through the ANN-based "HydroAlgo" algorithm is firstly compared with the outputs of the Soil Water Balance hydrological model (SWBM). The comparison is performed over Italy, by considering all the available overpasses of AMSR2, since July 2012. The SMC generated by HydroAlgo is then considered as input for generating a rainfall product through the SM2RAIN algorithm. The comparison between observed and estimated rainfall in central Italy provided satisfactory results with a substantial room for improvement. In this work, the ANN "HydroAlgo" algorithm [1], which was originally developed for AMSR-E, was adapted and re-trained for AMSR2, accounting for the two C band channels provided by this new sensor. The disaggregation technique implemented in HydroAlgo [2], devoted to the improvement of ground resolution, made this algorithm particularly suitable for the application to such a heterogeneous environment. The algorithm allows obtaining a SMC product with enhanced spatial resolution (0.1°), which is more suitable for hydrological applications. The AMSR2 derived SMC is compared with simulated data obtained from the application of a well-established soil water balance model [3]. The training and test of the algorithm are carried out on a test area in central Italy, while the entire Italy is considered for the validation. The last step of the activity is the use of the HydroAlgo SMC into the SM2RAIN algorithm [4], in order to exploit the potential contribution of this product at enhanced resolution for rainfall estimation. [1] E. Santi, S. Pettinato, S. Paloscia, P. Pampaloni, G. Macelloni, and M. Brogioni (2012), "An algorithm for generating soil moisture and snow depth

  7. 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

  8. Comparison of DMSP SSM/I and Landsat 7 ETM+ Sea Ice Concentrations During Summer Melt

    Science.gov (United States)

    Cavalieri, Donald J.; Markus, Thorsten; Ivanoff, Alvaro; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    As part of NASA's EOS Aqua sea ice validation program for the Advanced Microwave Scanning Radiometer (AMSR-E), Landsat 7 Enhanced Thematic Mapper (ETM+) images were acquired to develop a sea ice concentration data set with which to validate AMSR-E sea ice concentration retrievals. The standard AMSR-E Arctic sea ice concentration product will be obtained with the enhanced NASA Team (NT2) algorithm. The goal of this study is to assess the accuracy to which the NT2 algorithm, using DMSP Special Sensor Microwave Imager radiances, retrieves sea ice concentrations under summer melt conditions. Melt ponds are currently the largest source of error in the determination of Arctic sea ice concentrations with satellite passive microwave sensors. To accomplish this goal, Landsat 7 ETM+ images of Baffin Bay were acquired under clear sky conditions on the 26th and 27th of June 2000 and used to generate high-resolution sea ice concentration maps with which to compare the NT2 retrievals. Based on a linear regression analysis of 116 25-km samples, we find that overall the NT2 retrievals agree well with the Landsat concentrations. The regression analysis yields a correlation coefficient of 0.98. In areas of high melt ponding, the NT2 retrievals underestimate the sea ice concentrations by about 12% compared to the Landsat values.

  9. Freeboard, Snow Depth and Sea-Ice Roughness in East Antarctica from In Situ and Multiple Satellite Data

    Science.gov (United States)

    Markus, Thorsten; Masson, Robert; Worby, Anthony; Lytle, Victoria; Kurtz, Nathan; Maksym, Ted

    2011-01-01

    In October 2003 a campaign on board the Australian icebreaker Aurora Australis had the objective to validate standard Aqua Advanced Microwave Scanning Radiometer (AMSR-E) sea-ice products. Additionally, the satellite laser altimeter on the Ice, Cloud and land Elevation Satellite (ICESat) was in operation. To capture the large-scale information on the sea-ice conditions necessary for satellite validation, the measurement strategy was to obtain large-scale sea-ice statistics using extensive sea-ice measurements in a Lagrangian approach. A drifting buoy array, spanning initially 50 km 100 km, was surveyed during the campaign. In situ measurements consisted of 12 transects, 50 500 m, with detailed snow and ice measurements as well as random snow depth sampling of floes within the buoy array using helicopters. In order to increase the amount of coincident in situ and satellite data an approach has been developed to extrapolate measurements in time and in space. Assuming no change in snow depth and freeboard occurred during the period of the campaign on the floes surveyed, we use buoy ice-drift information as well as daily estimates of thin-ice fraction and rough-ice vs smooth-ice fractions from AMSR-E and QuikSCAT, respectively, to estimate kilometer-scale snow depth and freeboard for other days. The results show that ICESat freeboard estimates have a mean difference of 1.8 cm when compared with the in situ data and a correlation coefficient of 0.6. Furthermore, incorporating ICESat roughness information into the AMSR-E snow depth algorithm significantly improves snow depth retrievals. Snow depth retrievals using a combination of AMSR-E and ICESat data agree with in situ data with a mean difference of 2.3 cm and a correlation coefficient of 0.84 with a negligible bias.

  10. AquaBuOY

    DEFF Research Database (Denmark)

    Weinstein, Alla; Fredrikson, Göran; Claeson, Lennart

    2003-01-01

    BuOY in five representative generic sea states. Ocean energy and offshore wave energy conversion in the United States is at a significant milestone. During the next year, ocean energy technology developers and energy officials have the potential to deploy pilot scale ocean power plants and transition...... to commercial plants in the US. This capability comes at a time of increased interest in ocean energies at the National Academy of Sciences and the US Department of Energy. AquaEnergy will conclude its presentation with a brief overview of current legislation affecting the industry. In 2004, ocean scientists...

  11. 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.

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 78 FR 31627 - Thirteenth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S.

    Science.gov (United States)

    2013-05-24

    ... Special Committee 222, Inmarsat AMS(R)S. AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 222, Inmarsat AMS(R)S. SUMMARY: The FAA is..., Inmarsat AMS(R)S DATES: The meeting will be held June 10-11 from 9:00 a.m.-5:00 p.m. ADDRESSES: The...

  17. In aqua vivo EPID dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Wendling, Markus; McDermott, Leah N.; Mans, Anton; Olaciregui-Ruiz, Igor; Pecharroman-Gallego, Raul; Sonke, Jan-Jakob; Stroom, Joep; Herk, Marcel J.; Mijnheer, Ben van [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands)

    2012-01-15

    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 the original back-projection dose-reconstruction algorithm uses water-based scatter-correction kernels and therefore does not account for tissue inhomogeneities accurately. The aim of this study was to test a new method, in aqua vivo EPID dosimetry, for fast dose verification of lung cancer irradiations during actual patient treatment. Methods: The key feature of our method is the dose reconstruction in the patient from EPID images, obtained during the actual treatment, whereby the images have been converted to a situation as if the patient consisted entirely of water; hence, the method is termed in aqua vivo. This is done by multiplying the measured in vivo EPID image with the ratio of two digitally reconstructed transmission images for the unit-density and inhomogeneous tissue situation. For dose verification, a comparison is made with the calculated dose distribution with the inhomogeneity correction switched off. IMRT treatment verification is performed for each beam in 2D using a 2D {gamma} evaluation, while for the verification of volumetric-modulated arc therapy (VMAT) treatments in 3D a 3D {gamma} evaluation is applied using the same parameters (3%, 3 mm). The method was tested using two inhomogeneous phantoms simulating a tumor in lung and measuring its sensitivity for patient positioning errors. Subsequently five IMRT and five VMAT clinical lung cancer treatments were investigated, using both the conventional back-projection algorithm and the in aqua vivo method. The verification results of the in aqua vivo method were statistically analyzed for 751 lung cancer patients treated with IMRT and 50 lung cancer patients treated with VMAT. Results: The improvements by

  18. 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...

  19. 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...

  20. 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...

  1. 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 swaths....

  2. 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 swaths....

  3. Aqua jogging-induced pulmonary oedema.

    Science.gov (United States)

    Wenger, M; Russi, E W

    2007-12-01

    The present study reports the case of a 43-yr-old very sporty male, who developed shortness of breath and expectorated bloody froth during aqua jogging. Pulmonary oedema was diagnosed clinically and by computed tomography of the chest. The patient made a full recovery and his echocardiography was entirely normal. Pulmonary oedema occurring in healthy scuba-divers and swimmers has been reported previously. However, this is the first case where pulmonary oedema was observed during aqua jogging.

  4. 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

  5. An optimal estimation algorithm to derive Ice and Ocean parameters from AMSR Microwave radiometer observations

    DEFF Research Database (Denmark)

    Pedersen, Leif Toudal; Tonboe, Rasmus T.; Høyer, Jacob

    to the ESA CCI round robin reference dataset to verify improvements. A prescribed co-variance matrix both for the a priori set of parameters and for the suite of AMSR brightness temperatures are used in addition to constrain the retrieval. These matrices are derived from an analysis of the ESA CCI round...... robin reference dataset. Over open water the reference data is a co-location of satellite SST, ERA Interim re-analysis data and observed brightness temperatures. Over ice the reference data is a co-location of ERA Interim re-analysis data, and observed AMSR microwave brightness temperatures. Due...

  6. 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

  7. 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.

  8. Record Arctic Sea Ice Loss in 2007

    Science.gov (United States)

    2007-01-01

    This image of the Arctic was produced from sea ice observations collected by the Advanced Microwave Scanning Radiometer (AMSR-E) Instrument on NASA's Aqua satellite on September 16, overlaid on the NASA Blue Marble. The image captures ice conditions at the end of the melt season. Sea ice (white, image center) stretches across the Arctic Ocean from Greenland to Russia, but large areas of open water were apparent as well. In addition to record melt, the summer of 2007 brought an ice-free opening though the Northwest Passage that lasted several weeks. The Northeast Passage did not open during the summer of 2007, however, as a substantial tongue of ice remained in place north of the Russian coast. According to the National Snow and Ice Data Center (NSIDC), on September 16, 2007, sea ice extent dropped to 4.13 million square kilometers (1.59 million square miles)--38 percent below average and 24 percent below the 2005 record.

  9. Estimate of the Impact of Absorbing Aerosol Over Cloud on the MODIS Retrievals of Cloud Optical Thickness and Effective Radius Using Two Independent Retrievals of Liquid Water Path

    Science.gov (United States)

    Wilcox, Eric M.; Harshvardhan; Platnick, Steven

    2009-01-01

    Two independent satellite retrievals of cloud liquid water path (LWP) from the NASA Aqua satellite are used to diagnose the impact of absorbing biomass burning aerosol overlaying boundary-layer marine water clouds on the Moderate Resolution Imaging Spectrometer (MODIS) retrievals of cloud optical thickness (tau) and cloud droplet effective radius (r(sub e)). In the MODIS retrieval over oceans, cloud reflectance in the 0.86-micrometer and 2.13-micrometer bands is used to simultaneously retrieve tau and r(sub e). A low bias in the MODIS tau retrieval may result from reductions in the 0.86-micrometer reflectance, which is only very weakly absorbed by clouds, owing to absorption by aerosols in cases where biomass burning aerosols occur above water clouds. MODIS LWP, derived from the product of the retrieved tau and r(sub e), is compared with LWP ocean retrievals from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E), determined from cloud microwave emission that is transparent to aerosols. For the coastal Atlantic southern African region investigated in this study, a systematic difference between AMSR-E and MODIS LWP retrievals is found for stratocumulus clouds over three biomass burning months in 2005 and 2006 that is consistent with above-cloud absorbing aerosols. Biomass burning aerosol is detected using the ultraviolet aerosol index from the Ozone Monitoring Instrument (OMI) on the Aura satellite. The LWP difference (AMSR-E minus MODIS) increases both with increasing tau and increasing OMI aerosol index. During the biomass burning season the mean LWP difference is 14 g per square meters, which is within the 15-20 g per square meter range of estimated uncertainties in instantaneous LWP retrievals. For samples with only low amounts of overlaying smoke (OMI AI less than or equal to 1) the difference is 9.4, suggesting that the impact of smoke aerosols on the mean MODIS LWP is 5.6 g per square meter. Only for scenes with OMI aerosol index greater than 2 does the

  10. 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

  11. NOAA GCOM-W1/AMSR2 Oceanic Environmental Products: Phase-2

    Science.gov (United States)

    Jelenak, Z.; Alsweiss, S.; Chang, P.; Park, J. Y.

    2014-12-01

    Passive microwave radiometry is a special application of microwave communications technology for the purpose of collecting Earth's electromagnetic radiation. With the use of radiometers onboard earth orbiting satellites, scientists are able to monitor the Earth's environment and climate system on both short- and long-term temporal scales with near global coverage. The Global Change Observation Mission (GCOM) is part of the Japanese Aerospace Exploration Agency (JAXA) broader commitment toward global and long-term observation of the Earth's environment. GCOM consists of two polar orbiting satellite series, GCOM-W (Water) and GCOM-C (Climate), with 1-year overlap between them for inter-calibration. AMSR2 onboard GCOM-W1 is a microwave radiometer system that measures dual polarized radiances at 6.9, 7.3, 10.65, 18.7, 23.8, 36.5, and 89.0 GHz. It is a sun-synchronous orbiter that acquires microwave radiances by conically scanning the Earth's surface at a nominal earth incidence angle of 55 degrees that results in a wide swath of 1450 km. As a part of Joint Polar Satellite System (JPSS) program the National Oceanic and Atmospheric Administration (NOAA) GCOM-W1 product development and validation project will provide NOAA's users access to critical geophysical products derived from AMSR-2. These products, which are detailed in NOAA's JPSS Level 1 Requirements Document Supplement, include: microwave brightness temperature, total precipitable water, cloud liquid water, precipitation type/rate, sea surface temperature, and Sea Surface Wind Speed. Phase-1 of the AMSR-2 project at NOAA included inter-calibration of AMSR-2 measured brightness temperatures with the Tropical Rainfall Measuring Mission Microwave Imager as the reference radiometer. The second phase of the project utilized the calibrated brightness temperatures in a robust Bayesian network to retrieve more accurate geophysical parameters over the ocean surface. It can handle retrievals even with missing channels and

  12. Distributed land surface modeling with utilization of multi-sensor satellite data: application for the vast agricultural terrain in cold region

    Science.gov (United States)

    Muzylev, E.; Uspensky, A.; Gelfan, A.; Startseva, Z.; Volkova, E.; Kukharsky, A.; Romanov, P.; Alexandrovich, M.

    2012-04-01

    A technique for satellite-data-based modeling water and heat regimes of a large scale area has been developed and applied for the 227,300 km2 agricultural region in the European Russia. The core component of the technique is the physically based distributed Remote Sensing Based Land Surface Model (RSBLSM) intended for simulating transpiration by vegetation and evaporation from bare soil, vertical transfer of water and heat within soil and vegetation covers during a vegetation season as well as hydrothermal processes in soil and snow covers during a cold season, including snow accumulation and melt, dynamics of soil moisture and temperature during soil freezing and thawing, infiltration into frozen soil. Processes in the "atmosphere-snow-frozen soil" system are critical for cold region agriculture, as they control crop development in early spring before the vegetation season beginning. For assigning the model parameters as well as for preliminary calibrating and validating the model, available multi-year data sets of soil moisture/temperature profiles, evaporation, snow and soil freezing depth measured at the meteorological stations located within the study region have been utilized. To provide an appropriate parametrization of the model for the areas where ground-based measurements are unavailable, estimates have been utilized for vegetation, meteorological and snow characteristics derived from the multispectral measurements of AVHRR/NOAA (1999-2010), MODIS/EOS Terra & Aqua (2002-2010), AMSR-E/Aqua (2003-2004; 2008-2010), and SEVIRI/Meteosat-9 (2009-2010). The technologies of thematic processing the listed satellite data have been developed and applied to estimate the land surface and snow cover characteristics for the study area. The developed technologies of AVHRR data processing have been adapted to retrieve land surface temperature (LST) and emissivity (E), surface-air temperature at a level of vegetation cover (TA), normalized vegetation index (NDVI), leaf

  13. 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

  14. Terra and Aqua MODIS Instrument Status

    Science.gov (United States)

    Xiong, X.; Wenny, B.; Sun, J.; Angal, A.; Barnes, W.

    2010-12-01

    Since launch, Terra MODIS has successfully operated for more than 10 years and Aqua MODIS for more than 8 years. Together, they have produced an unprecedentedly large amount of data products from their complementary morning and afternoon observations, over a wide spectral range from visible (VIS) to long-wave infrared (LWIR), and significantly benefited the science community for studies of changes in the Earth’s system and environment. On-orbit changes in sensor radiometric responses, spectral, and spatial characteristics are constantly monitored by a set of on-board calibrators (OBC), which include a solar diffuse, a solar diffuser stability monitor, a blackbody, and a spectroradiometric calibration assembly. In addition to using the OBC, lunar observations have been regularly scheduled and implemented in order to independently monitor changes in sensor radiometric responses. The MODIS Characterization Support Team (MCST) at NASA/GSFC is responsible for the operation and calibration of both MODIS instruments, including their Level 1B algorithm maintenance and improvements. This paper reports current status of both Terra and Aqua MODIS on-orbit operation and calibration activities and summaries their long-term radiometric, spectral, and spatial performance. Existing challenges, lessons learned, and future calibration efforts are also discussed.

  15. Poly[tri-μ-aqua-diaqua-μ-phosphonoformato-cobalt(IIsodium

    Directory of Open Access Journals (Sweden)

    Xu-Jian Luo

    2013-06-01

    Full Text Available The title complex, [CoNa(CO5P(H2O5]n, was obtained by reacting sodium phosphonoformate with cobalt nitrate. The complex contains cobalt(II and sodium ions, which are bridged by the O atoms of two aqua ligands. The CoII ion is octahedrally coordinated by three phosphonoformato ligands (one bi- and the other monodentate and by two O atoms from the bridging aqua ligands. The sodium cation is hexacoordinated by six O atoms from four bridging and two terminal aqua ligands. The complex molecules are linked to give a three-dimensional structure by phosphonoformate ligands bridging CoII atoms and water molecules establishing cobalt–sodium bridges. O—H...O hydrogen bonding between the aqua ligands and all O atoms of the phosphonoformato ligand and neighbouring aqua ligands help to consolidate the packing.

  16. 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.

  17. 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.

  18. The Study on Safety of Scolopendrid Aqua-acupuncture

    Directory of Open Access Journals (Sweden)

    Lim Seung-il

    2004-02-01

    Full Text Available Objective : Recently scolopendrid aqua-acupuncture has been a good effect on pain control but it has not been known about clinical safety. The purpose of this study was to investigate acute toxicity of scolopendrid aqua-acupuncture. Method : In order to prove the clinical safety of scolopendrid aqua-acupuncture, We have observed a bacteriological examination and clinical pathology test after scolopendrid aqua-acupuncture treatment. Balb/c mice were injected intravenous with Scolopendrid aquaacupuncture treatment for and acute toxicity test. We analyzed physical reaction(side effectand clinical pathology test before and after Scolopendrid aqua-acupuncture treatment of mice and 20 patients suffering from pain, who admitted department of Acupunture and Moxibustion, College of Oriental Medicine, Won-Kwang University Kwangju hospital. Results : In the Blood agar plate and Nutrient agar plate, a bacteriological examination did not show a bacillus. In acute toxicity test, there was no mortality thus unable to attain the value. Examining the toxic response in the acute toxicity test, there was no sign of toxication. In acute toxic test, running biochemical serum test couldn't yield any differences between the control and experiment groups. In the 20 patients treated with Scolopendrid aqua-acupuncture, hematologic test did not show remarkable change. In the 20 patients treated with Scolopendrid aqua-acupuncture, Liver function test(AST, ALT, ALP showed a slight decrease on the contrary, and abnormal rate showed a decrease of 5.0% compared with previous study. Reanl function test(BUN, Cr and abnormal rate showed a decrease of 5.0% compared with previous study. In the 20 patients treated with Scolopendrid aqua-acupuncture, Electrolyte were normal range before and after treatment. In the Urine analysis of 20 patients, Leukocyte, Protein, Glucose, Keton, Bilirubin, U-bilinogen were not detected before and after Scolopendrid aqua-acupuncture treatment, and

  19. 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.

  20. 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...

  1. Calibration Adjustments to the MODIS Aqua Ocean Color Bands

    Science.gov (United States)

    Meister, Gerhard

    2012-01-01

    After the end of the SeaWiFS mission in 2010 and the MERIS mission in 2012, the ocean color products of the MODIS on Aqua are the only remaining source to continue the ocean color climate data record until the VIIRS ocean color products become operational (expected for summer 2013). The MODIS on Aqua is well beyond its expected lifetime, and the calibration accuracy of the short wavelengths (412nm and 443nm) has deteriorated in recent years_ Initially, SeaWiFS data were used to improve the MODIS Aqua calibration, but this solution was not applicable after the end of the SeaWiFS mission_ In 2012, a new calibration methodology was applied by the MODIS calibration and support team using desert sites to improve the degradation trending_ This presentation presents further improvements to this new approach. The 2012 reprocessing of the MODIS Aqua ocean color products is based on the new methodology.

  2. 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...

  3. Status of Terra and Aqua MODIS Instruments

    Science.gov (United States)

    Xiong, X.; Wenny, B. N.; Kuyper, J. R.; Salomonson, V. V.; Barnes, W. L.

    2008-12-01

    Currently, two nearly identical MODIS instruments are operating in space: one on the Terra spacecraft launched in December 1999 and another on the Aqua spacecraft launched in May 2002. MODIS has 36 spectral bands with wavelengths covering from visible (VIS) to long-wave infrared (LWIR). Since launch, MODIS observations and data products have contributed significantly to studies of changes in the Earth system of land, oceans, and atmosphere. To maintain its on-orbit calibration and data product quality, MODIS was built with a comprehensive set of on-board calibrators, consisting of a solar diffuser (SD) and a solar diffuser stability monitor (SDSM) for the reflective solar bands (RSB) and an on-board blackbody (BB) for the thermal emissive bands (TEB). Both instruments have demonstrated good performance. The primary Level-1B (L1B) data products are top of the atmosphere (TOA) reflectance for RSB and radiance for TEB. This paper provides an overview of MODIS calibration methodologies, activities, lifetime on-orbit performance and challenging issues for each MODIS, the impact on L1B product quality, and lessons learned for future sensors such as the NPOESS VIIRS.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Remote Sensing of Climatic Anomalies and West Nile Virus Risk in the United States

    Science.gov (United States)

    Wimberly, M. C.; Chuang, T.; Henebry, G. M.; Kimball, J. S.

    2012-12-01

    associated with increased risk of WNV outbreaks, but moisture effects are more variable and are contingent upon regional differences in landscape hydrology and vector and host species. Although the AMSR-E sensor on Aqua ceased effective operations in October 2011 due to a sensor malfunction, similar satellite microwave observations from WindSat and AMSR2 sensors will enable the continuation of global land parameter retrievals and support future applications for modeling and forecasting WNV and other mosquito-borne diseases.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 利用MODIS和AMSR-E进行积雪制图的比较分析%A Comparison of MODIS and Passive Microwave Snow Mappings

    Institute of Scientific and Technical Information of China (English)

    延昊

    2005-01-01

    MODIS和被动微波辐射计AMSR-E提供了识别积雪的不同方法. MODIS首先计算反映积雪在1.6 μm强吸收特性的归一化差值积雪指数NDSI, 在剔除卷云的影响后, 得到MODIS积雪分布. AMSR-E则根据积雪在微波波段的差异性散射特性识别积雪. 通过案例分析比较了MODIS和AMSR-E积雪分布, 发现由于云的遮蔽使MODIS积雪分布面积会比实际小, 但由于MODIS的空间分辨率很高, 得到的积雪边界线轮廓清晰. 而微波由于不受云的影响, 得到的AMSR-E积雪分布比较符合实际, 但积雪的边界线较粗.

  15. 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 ...

  16. 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

  17. 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

  18. 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.

  19. Investigating High-Resolution AMSR2 Sea Ice Concentrations during the February 2013 Fracture Event in the Beaufort Sea

    Directory of Open Access Journals (Sweden)

    Alexander Beitsch

    2014-04-01

    Full Text Available Leads with a length on the order of 1000 km occurred in the Beaufort Sea in February 2013. These leads can be observed in Moderate Resolution Imaging Spectroradiometer (MODIS images under predominantly clear sky conditions. Sea ice concentrations (SIC derived from the Advanced Microwave Scanning Radiometer 2 (AMSR2 using the Bootstrap (BST algorithm fail to show the lead occurrences, as is visible in the MODIS images. In contrast, SIC derived from AMSR2 using the Arctic Radiation and Turbulence Interaction Study (ARTIST sea ice algorithm (ASI reveal the lead structure, due to the higher spatial resolution possible when using 89-GHz channel data. The ASI SIC are calculated from brightness temperatures interpolated on three different grids with resolutions of 3.125 km (ASI-3k, 6.25 km (ASI-6k and 12.5 km (ASI-12k to investigate the effect of the spatial resolution. Single-swath data is used to study the effect of temporal sampling in comparison to daily averages. For a region of interest in the Beaufort Sea, BST and ASI-3k show area-averaged SIC of 97%±0.7% and 93%±7.0%, respectively. For ASI-6k, the area-averaged SIC are similar to ASI-3k, while ASI-12k data show more agreement with BST. Visual comparison with MODIS True Color imagery exhibits good agreement with ASI-3k. In particular, ASI-3k are able to reproduce lead structure and size in the sea ice cover, which are not or are less visible in the other SIC data. The results will be valuable for selecting a SIC data product for studies of the interaction between ocean, ice, and atmosphere in the polar regions.

  20. [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.

  1. 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

  2. Modeling Land Surface Phenology Using Earthlight

    Science.gov (United States)

    Henebry, G. M.

    2005-12-01

    Microwave radiometers have long been used in earth observation, but the coarse spatial resolution of the data has discouraged its use in investigations of the vegetated land surface. The Advanced Microwave Scanning Radiometer (AMSR-E) on the Aqua satellite acquires multifrequency observations twice daily (1:30 and 13:30). From these brightness temperatures come two data products relevant to land surface phenology: soil moisture and vegetation water content. Although the nominal spatial resolution of these products is coarse (25 km), the fine temporal sampling allows characterization of the diel variation in surface moisture as contained in the uppermost soil layer and bound in the vegetation canopy. The ephermal dynamics of surficial soil moisture are difficult to validate due to the scale discrepancy between the 625 sq km coverage of a single pixel and the sparse network of weather stations. In contrast, canopy dynamics are more readily validated using finer spatial resolution data products and/or ecoregionalizations. For sites in the North American Great Plains and Northern Eurasia dominated by herbaceous vegetation, I will present land surface phenologies modeled using emitted earthlight and compare them with land surface phenologies modeled using reflected sunlight. I will also explore whether some key climate modes have a significant effect on the microwave-retrieved land surface phenologies.

  3. Satellite Observations of the Drought Factor and Their Applications to Bushfire Risk Assessment

    Science.gov (United States)

    Ryu, D.; McColl, K. A.

    2010-12-01

    Estimating moisture content of surface soil and biomass is important not only for monitoring vegetation water stress and primary production but also for assessing the risk of natural hazards such as land slide and bushfire. There exist a number of methods to estimate spatially distributed land surface dryness using remotely sensed surface emissions in visible, infrared and microwave ranges. In this work, a lumped index of surface dryness, which is reflecting the moisture content in the surface soil and biomass, is generated using the ratio of the surface temperature to the air temperature. Daily time series of surface temperature observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard Aqua is used with gauge-interpolated air temperature over the entire region of Victoria, Australia. As an alternative source of the surface temperature, 37 GHz microwave emission observed by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) is used and compared with the MODIS-based estimates. Daily time series of the surface dryness index is then sampled in the area burned during the Black Saturday bushfire in February 2009 to explore the utility of the index for estimating the Drought Factor (DF); DF is a key input to the Forest Fire Danger Index (FFDI). The surface dryness index, based on both thermal infrared and microwave emissions, exhibit significant increase prior to the Black Saturday bushfire. The remotely sensed surface dryness index is compared with the operational Drought Factor and implications of the results are discussed.

  4. 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.

  5. Simulations of Atmospheric River Overland Precipitation with a Spectral Microphysics Mesoscale Model and G-SDSU as Compared to Remote Sensing Data

    Science.gov (United States)

    Han, M.; Braun, S. A.; Matsui, T.; Iguchi, T.; Williams, C. R.

    2012-12-01

    A spectral microphysics scheme, HUCM, is recently implemented into the Weather Research and Forecasting (WRF) model and the Goddard Satellite Data Simulator Unit (G-SDSU). With this state-of-the-art numerical representation of cloud and precipitation processes in the WRF model, simulations were conducted for an Atmospheric River (AR) precipitation event in the US west coast on 30 to 31 December 2005. During this period, the intense AR transported abundant moisture, produced intense precipitation, and resulted in large hydrological impacts over California and Nevada. The Advanced Microwave Scanning Radiometer for EOS (AMSR-E) onboard NASA Aqua satellite and a ground-based precipitation profiling radar sampled this storm. The G-SDSU is used to simulate the brightness temperature and radar backscatter signals at the instruments' operating frequencies. Analysis shows improvement of ice scattering signature in this simulation with HUCM scheme vs. simulations with several other bulk schemes (done in a previous study). It indicates a better representation of precipitation ice water path in the WRF model with the spectral microphysics scheme. Further analysis of simulated radar signal will be conducted. The structure of the storm will also be examined.

  6. Evaluating Frontal Precipitation with a Spectral Microphysics Mesoscale Model and a Satellite Simulator as Compared to Radar and Radiometer Observations

    Science.gov (United States)

    Han, M.; Braun, S. A.; Matsui, T.; Iguchi, T.; Williams, C. R.

    2013-12-01

    The Advanced Microwave Scanning Radiometer for EOS (AMSR-E) onboard NASA Aqua satellite and a ground-based precipitation profiling radar sampled a frontal precipitation event in the US west coast on 30 to 31 December 2005. Simulations with bulk microphysics schemes in the Weather Research and Forecast (WRF) model have been evaluated with those remote sensing data. In the current study, we continue similar work to evaluate a spectral bin microphysics (SBM) scheme, HUCM, in the WRF model. The Goddard-Satellite Data Simulation Unit (G-SDSU) is used to simulate quantities observed by the radar and radiometer. With advanced representation of cloud and precipitation microphysics processes, the HUCM scheme predicts distributions of 7 hydrometeor species as storms evolve. In this study, the simulation with HUCM well captured the structure of the precipitation and its microphysics characteristics. In addition, it improved total precipitation ice mass simulation and corrected, to a certain extent, the large low bias of ice scattering signature in the bulk scheme simulations. However, the radar reflectivity simulations with the HUCM scheme were not improved as compared to the bulk schemes. We conducted investigations to understand how microphysical processes and properties, such as snow break up parameter and particle fall velocities would influence precipitation size distribution and spectrum of water paths, and further modify radar and/or radiometer simulations. Influence by ice nuclei is going to be examined as well.

  7. Recycling of sludge with the Aqua Reci process.

    Science.gov (United States)

    Stendahl, K; Jäfverström, S

    2004-01-01

    Supercritical Water Oxidation (SCWO) is an innovative and effective destruction method for organics in sewage sludge. The SCWO process leaves a slurry of inorganic ash in a pure water phase free from organic contaminants, which opens possibilities for a simple process to recover components like phosphates and/or coagulants from the sewage sludge, a process marketed as the Aqua Reci. In a continuous pilot plant for the SCWO process digested sludge has been treated. The ash has been extracted in lab- and pilot scale with both caustic and acids in order to recover phosphates and coagulants. The particle size of the inorganic contaminants in the water after the SCWO process is between 1-10 microm, which means that it is very reactive. The phosphate, and partly the aluminium, can be extracted with caustic as iron and heavy metals are completely insoluble in caustic. This is a method to separate the phosphates from the rest of the contaminants. However, high calcium content will bind the phosphate as calcium phosphate insoluble in caustic. In most cases the calcium content is too high and the best solution is to dissolve phosphates and all metals with sulphuric acid. From this solution first iron phosphate can be separated and thereafter in a second step aluminium and finally heavy metals in a third step. Iron can be separated from the phosphate, either by leaching the phosphate with caustic off to sodium phosphate leaving a precipitate consisting of iron hydroxide, or the iron phosphate can be dissolved in hydrochloric acid followed by a liquid extraction process where ferric chloride can be separated leaving a phosphoric acid. By the acid dissolving process it is possible to recover phosphate, iron, aluminium, and heavy metals from the inorganic since the Aqua Reci process only leaves a silica residue representing about 10% of the DS content in the original sludge.

  8. 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. 

  9. 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...

  10. Diffuse Attenuation Coef. K490, Aqua MODIS, NPP, 0.125 degrees, East US

    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...

  11. 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...

  12. 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.

  13. 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...

  14. 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...

  15. 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...

  16. SST, Aqua MODIS, NPP, 0.0125 degrees, West US, Day time (11 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. SST, Aqua MODIS, NPP, 0.0125 degrees, Gulf of Mexico, Day time (11 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...

  6. 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...

  7. 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...

  8. 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...

  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. A Full Snow Season in Yellowstone: A Database of Restored Aqua Band 6

    Science.gov (United States)

    Gladkova, Irina; Grossberg, Michael; Bonev, George; Romanov, Peter; Riggs, George; Hall, Dorothy

    2013-01-01

    The algorithms for estimating snow extent for the Moderate Resolution Imaging Spectroradiometer (MODIS) optimally use the 1.6- m channel which is unavailable for MODIS on Aqua due to detector damage. As a test bed to demonstrate that Aqua band 6 can be restored, we chose the area surrounding Yellowstone and Grand Teton national parks. In such rugged and difficult-to-access terrain, satellite images are particularly important for providing an estimation of snow-cover extent. For the full 2010-2011 snow season covering the Yellowstone region, we have used quantitative image restoration to create a database of restored Aqua band 6. The database includes restored radiances, normalized vegetation index, normalized snow index, thermal data, and band-6-based snow-map products. The restored Aqua-band-6 data have also been regridded and combined with Terra data to produce a snow-cover map that utilizes both Terra and Aqua snow maps. Using this database, we show that the restored Aqua-band-6-based snow-cover extent has a comparable performance with respect to ground stations to the one based on Terra. The result of a restored band 6 from Aqua is that we have an additional band-6 image of the Yellowstone region each day. This image can be used to mitigate cloud occlusion, using the same algorithms used for band 6 on Terra. We show an application of this database of restored band-6 images to illustrate the value of creating a cloud gap filling using the National Aeronautics and Space Administration s operational cloud masks and data from both Aqua and Terra.

  11. Thermal and aqua-reserve characteristics of an aqua-reserver using a super-absorbent polymer gel; Kokyusuisei jushi wo mochiita hosuizai no hosui netsutokusei

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Z. [Tokyo Metropolitan Univ., Tokyo (Japan); Asako, Y.; Yamaguchi, Y.; Yoshida, H. [Tokyo Metropolitan Univ., Tokyo (Japan). Faculty of Technology

    1997-09-25

    This paper describes thermal and aqua-reserve characteristics of a super-absorbent polymer gel which absorbs an aqueous solution of calcium chloride as a heat absorbent in a firewall during fire. Only gels which absorbed 10 to 40 mass% of the solutions were tested. The absorbency of the polymer and latent heat of the gel were measured using a thermal analyzer of TG/DTA. To obtain the aqua-reserve characteristics, changes in weight of the gel which was left in a room under controlled temperature was measured. Also, an equilibrium concentration of the calcium chloride solution in the gel was obtained. 8 refs., 12 figs., 3 tabs.

  12. 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.

  13. 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.

  14. 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 ...

  15. "Aqua-space", a new headspace method for isolation of natural floral aromas using humidified air as a carrier gas.

    Science.gov (United States)

    Ishikawa, Masashi; Honda, Tsutomu; Fujita, Akira; Kurobayashi, Yoshiko; Kitahara, Takeshi

    2004-02-01

    A new method called "Aqua-space" was developed for the isolation of the natural fragrances of plants. Living flowers were enclosed in a space under simulated natural conditions, and humidified air was pumped into the space as a fragrance carrier. In a comparison among three isolation methods, i.e., Aqua-space, headspace, and solvent extraction, the Aqua-space method proved to be the most effective in retaining natural fragrances with abundant oxygenated components key to floral fragrances.

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

    Directory of Open Access Journals (Sweden)

    Md. Ariful Islam

    2014-02-01

    Full Text Available 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.

  17. 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.

  18. Ross Sea Polynyas: Response of Ice Concentration Retrievals to Large Areas of Thin Ice

    Science.gov (United States)

    Kwok, R.; Comiso, J. C.; Martin, S.; Drucker, R.

    2007-01-01

    For a 3-month period between May and July of 2005, we examine the response of the Advanced Microwave Scanning Radiometer (AMSR-E) Enhanced NASA Team 2 (NT2) and AMSR-E Bootstrap (ABA) ice concentration algorithms to large areas of thin ice of the Ross Sea polynyas. Coincident Envisat Synthetic Aperture Radar (SAR) coverage of the region during this period offers a detailed look at the development of the polynyas within several hundred kilometers of the ice front. The high-resolution imagery and derived ice motion fields show bands of polynya ice, covering up to approximately 105 km(sup 2) of the Ross Sea, that are associated with wind-forced advection. In this study, ice thickness from AMSR-E 36 GHz polarization information serves as the basis for examination of the response. The quality of the thickness of newly formed sea ice (<10 cm) from AMSR-E is first assessed with thickness estimates derived from ice surface temperatures from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The effect of large areas of thin ice in lowering the ice concentration estimates from both NT2/ABA approaches is clearly demonstrated. Results show relatively robust relationships between retrieved ice concentrations and thin ice thickness estimates that differ between the two algorithms. These relationships define the approximate spatial coincidence of ice concentration and thickness isopleths. Using the 83% (ABA) and 91% (NT2) isopleths as polynya boundaries, we show that the computed coverage compares well with that using the estimated 10-cm thickness contour. The thin ice response characterized here suggests that in regions with polynyas, the retrieval results could be used to provide useful geophysical information, namely thickness and coverage.

  19. 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

  20. Satellite Microwave Remote Sensing for Environmental Modeling of Mosquito Population Dynamics

    Science.gov (United States)

    Chuang, Ting-Wu; Henebry, Geoffrey M.; Kimball, John S.; VanRoekel-Patton, Denise L.; Hildreth, Michael B.; Wimberly, Michael C.

    2012-01-01

    Environmental variability has important influences on mosquito life cycles and understanding the spatial and temporal patterns of mosquito populations is critical for mosquito control and vector-borne disease prevention. Meteorological data used for model-based predictions of mosquito abundance and life cycle dynamics are typically acquired from ground-based weather stations; however, data availability and completeness are often limited by sparse networks and resource availability. In contrast, environmental measurements from satellite remote sensing are more spatially continuous and can be retrieved automatically. This study compared environmental measurements from the NASA Advanced Microwave Scanning Radiometer on EOS (AMSR-E) and in situ weather station data to examine their ability to predict the abundance of two important mosquito species (Aedes vexans and Culex tarsalis) in Sioux Falls, South Dakota, USA from 2005 to 2010. The AMSR-E land parameters included daily surface water inundation fraction, surface air temperature, soil moisture, and microwave vegetation opacity. The AMSR-E derived models had better fits and higher forecasting accuracy than models based on weather station data despite the relatively coarse (25-km) spatial resolution of the satellite data. In the AMSR-E models, air temperature and surface water fraction were the best predictors of Aedes vexans, whereas air temperature and vegetation opacity were the best predictors of Cx. tarsalis abundance. The models were used to extrapolate spatial, seasonal, and interannual patterns of climatic suitability for mosquitoes across eastern South Dakota. Our findings demonstrate that environmental metrics derived from satellite passive microwave radiometry are suitable for predicting mosquito population dynamics and can potentially improve the effectiveness of mosquito-borne disease early warning systems. PMID:23049143

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. A cationic rhodium(I N-heterocyclic carbene complex isolated as an aqua adduct

    Directory of Open Access Journals (Sweden)

    Ashley L. Huttenstine

    2011-09-01

    Full Text Available The title complex, aqua[1,3-bis(2,6-diisopropylphenylimidazol-2-ylidene](η4-cycloocta-1,5-dienerhodium(I tetrafluoridoborate, [Rh(C8H12(C27H36N2(H2O]BF4, exihibits a square-planar geometry around the Rh(I atom, formed by a bidentate cycloocta-1,5-diene (cod ligand, an N-heterocylcic carbene and an aqua ligand. The complex is cationic and a BF4− anion balances the charge. The structure exists as a hydrogen-bonded dimer in the solid state, formed via interactions between the aqua ligand H atoms and the BF4− F atoms.

  6. AQUA Cloning: A Versatile and Simple Enzyme-Free Cloning Approach.

    Directory of Open Access Journals (Sweden)

    Hannes M Beyer

    Full Text Available Assembly cloning is increasingly replacing conventional restriction enzyme and DNA-ligase-dependent cloning methods for reasons of efficiency and performance. Here, we describe AQUA (advanced quick assembly, a simple and versatile seamless assembly cloning approach. We demonstrate the applicability and versatility of AQUA Cloning in selected proof-of-principle applications including targeted insertion-, deletion- and site-directed point-mutagenesis, and combinatorial cloning. Furthermore, we show the one pot de novo assembly of multiple DNA fragments into a single circular plasmid encoding a complex light- and chemically-regulated Boolean A NIMPLY B logic operation. AQUA Cloning harnesses intrinsic in vivo processing of linear DNA fragments with short regions of homology of 16 to 32 bp mediated by Escherichia coli. It does not require any kits, enzymes or preparations of reagents and is the simplest assembly cloning protocol to date.

  7. 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.

  8. 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.

  9. 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].

  10. 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.

  11. 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。

  12. 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.

  13. 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.

  14. Analysis of soil moisture retrieval and response to meteorological factors using AMSR-2%基于AMSR-2蒙古高原土壤水分反演及对气象因子响应分析

    Institute of Scientific and Technical Information of China (English)

    魏宝成; 玉山; 贾旭; 包玉海; 那日苏; 银山

    2016-01-01

    土壤水分是地表水文过程研究的一个重要参数,是众多环境因子综合作用的结果,科学判定土壤水分对环境因子的响应特性,对在蒙古高原地区开展干旱监测预警,调整农业生产结构,改善区域生态环境具有重要意义.本研究基于AMSR-2观测亮温、SPOT-NDVI数据,利用微波辐射传输模型及粗糙地表发射率Qp模型,构建适合蒙古高原的土壤水分反演方程,同时将模型应用于2013年蒙古高原植被生长期土壤水分反演.在此基础上,结合TRMM 3B43降雨量及气象站点气温数据,探讨了蒙古高原土壤水分对气象因子及植被的响应特性.结果表明:1)构建的蒙古高原表层土壤水分反演模型精度较高,土壤水分反演值与实测值的判定系数为0.6806,均方根误差(RMSE)达0.0316 cm3·cm-3,反演结果明显优于JAXA提供的AMSR-2土壤水分产品数据(RMSE=0.0441 cm3·cm-3).2)TRMM 3B43降雨数据与实测降雨量线性拟合,其判定系数为0.8598,直线拟合斜率K=0.9415,在数值上较站点实测值略微偏低,表明TRMM 3B43数据精度较高,在蒙古高原具有很好的适用性.3)蒙古高原植被生长期土壤水分、植被指数及降水量在空间格局上均表现出由北向南、由东北向西南逐渐减少的趋势.干旱区,土壤水分对气温变化最敏感,二者表现出显著正相关关系,其次为降水和植被;半干旱区,植被是影响土壤水分的关键因子,而气温与降水对土壤水分影响呈现出季节性变化;半湿润区3个因子对土壤水分的影响程度表现为植被>降水>气温.总之,利用土壤水分对气象因子和植被的响应特性,可以采取适当措施降低蒙古高原灾害发生风险,为区域生态环境建设提供科学依据.%Soil moisture is an important component of the hydrologic cycle in terrestrial ecosystems and it is critical for predicting and understanding various hydrological processes, including changes in weather

  15. 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.

  16. 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 ...

  17. 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 ...

  18. Aqua-Aura QuickDAM (QDAM) 2.0 Ops Concept

    Science.gov (United States)

    Nidhiry, John

    2015-01-01

    The presentation describes the Quick Debris Avoidance Maneuver (QDAM) 2.0 process used the Aqua and Aura flight teams to (a) reduce the work load and dependency on staff and systems; (b) reduce turn-around time and provide emergency last minute capabilities; and (c) increase burn parameter flexibility. The presentation also compares the QDAM 2.0 process to previous approaches.

  19. 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

  20. 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.

  1. 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 the...

  2. 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 the...

  3. 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 the...

  4. 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 the...

  5. 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

  6. Comparing Ship Track Droplet Sizes Inferred from Terra and Aqua MODIS Data

    Science.gov (United States)

    Kabataş, B.; Menzel, W. P.; Bilgili, A.; Gumley, L. E.

    2012-04-01

    The motivation of the study is to investigate cloud micro physics of ship tracks as a function of time. The paper describes how droplet effective radii retrieved from Moderate Resolution Imaging Spectroradiometer (MODIS) imagery for a selected set of ship tracks appear to grow from the beginning of the track towards the end of the track. MODIS 1 km observations of morning (Terra) and afternoon (Aqua) passes were analyzed to estimate the droplet sizes (and their changes in time) of the aerosols that formed the ship tracks. Ship tracks are the low-level anthropogenic clouds that form around the exhaust released by ships. They modify the overlying cloud albedo by having high particle concentration and small droplet size and thus can be detected from higher reflectivity in near infrared imagery, especially in 2.13 µm observations where they appear as bright features. The MODIS Cloud Product (MOD06 from Terra and MYD06 from Aqua) is used to estimate droplet size change in ship exhaust plumes with time in case studies from different parts of the northern hemisphere. Ship track pairs were chosen both in Terra and Aqua MODIS images to estimate the droplet size change from morning to afternoon. Droplet size increased with time in the atmosphere as measured by distance from the ship. Terra and Aqua MODIS droplet size estimates were in good agreement and are found to be between 6 and 17 µm with droplet size increase at an average rate between 0.5 to 1 µm per hour. Terra and Aqua MODIS results are found to be 90±8% correlated with each other. The case studies further demonstrated stability of the MOD06 algorithm. Key words: Ship Tracks, Anthropogenic clouds, Remote sensing, MODIS, Droplet size

  7. 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.

  8. 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.

  9. Preliminary study on the application of MODIS (Terra/Aqua) data on forest fire monitoring in Fujian%简析MODIS(Terra/Aqua)数据在福建省森林火灾监测中的应用

    Institute of Scientific and Technical Information of China (English)

    黄朝法; 刘菊容

    2007-01-01

    从目前福建省卫星林火监测应用实际出发,通过几种常用气象卫星功能介绍和对比,阐述MODIS(Terra/Aqua)数据在森林火灾监测中的应用优势,并简析MODIS(Terra/Aqua)数据在福建省林火监测中的应用现状.

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

    OpenAIRE

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

    2011-01-01

    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 ...

  11. 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)

  12. 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.

  13. 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.

  14. 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

  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. 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

  17. Computing pK(A) values of hexa-aqua transition metal complexes.

    Science.gov (United States)

    Galstyan, Gegham; Knapp, Ernst-Walter

    2015-01-15

    Aqueous pKA values for 15 hexa-aqua transition metal complexes were computed using a combination of quantum chemical and electrostatic methods. Two different structure models were considered optimizing the isolated complexes in vacuum or in presence of explicit solvent using a QM/MM approach. They yield very good agreement with experimentally measured pKA values with an overall root mean square deviation of about 1 pH unit, excluding a single but different outlier for each of the two structure models. These outliers are hexa-aqua Cr(III) for the vacuum and hexa-aqua Mn(III) for the QM/MM structure model. Reasons leading to the deviations of the outlier complexes are partially explained. Compared to previous approaches from the same lab the precision of the method was systematically improved as discussed in this study. The refined methods to obtain the appropriate geometries of the complexes, developed in this work, may allow also the computation of accurate pKA values for multicore transition metal complexes in different oxidation states.

  18. 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.

  19. 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

  20. 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.

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

    Science.gov (United States)

    Kuchment, L. S.; Romanov, P.; Gelfan, A. N.; Demidov, V. N.

    2009-08-01

    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.

  2. 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

  3. The NOAA Microwave Integrated Retrieval System (MiRS): Recent Science Improvements and Validation Results

    Science.gov (United States)

    Grassotti, C.; Zhan, X.; Boukabara, S. A.; Chattopadhyay, M.; Smith, C. K.; Islam, T.; Davies, J. E.

    2015-12-01

    The Microwave Integrated Retrieval System (MiRS) has been the NOAA official operational microwave retrieval algorithm since 2007 and is currently run operationally on microwave data from NOAA-18, NOAA-19, MetopA, MetopB/AMSU-MHS, DMSP F-17, F-18/SSMIS, Suomi-NPP/ATMS, and Megha-Tropics/SAPHIR. It has also been run experimentally on data from TRMM/TMI, Aqua/AMSR-E, GCOM-W1/AMSR2, and GPM/GMI. Future plans include operational processing of JPSS-1/ATMS, DMSP F-19/SSMIS, and GPM/GMI data. The inversion within MiRS follows a 1D-variational methodology, in which the fundamental physical attributes affecting the microwave observations are retrieved physically, including the profile of atmospheric temperature, water vapor, liquid and frozen hydrometeors, as well as surface emissivity and temperature. The community radiative transfer model (CRTM) is used as the forward and Jacobian operator to simulate the radiances at each iteration prior to fitting the measurements to within the noise level. The retrieved surface properties are then used to determine surface physical characteristics, including, when appropriate, cryospheric parameters such as sea ice concentration, ice age, and snow water amount, using pre-determined relationships that link emissivity and effective skin temperature to these parameters. We present a review of science improvements included in the recently released MiRS v11.1 that have led to higher quality atmospheric and surface parameter retrievals, with the improvements quantified by comparison with relevant atmospheric and surface reference data.

  4. Near real-time model to monitor SST anomalies related to undersea earthquakes and SW monsoon phenomena from TRMM-AQUA satellite data

    Science.gov (United States)

    Chakravarty, Subhas

    Near real-time interactive computer model has been developed to extract daily mean global Sea Surface Temperature (SST) values of 1440x720 pixels, each one covering 0.25° x0.25° lat-long area and SST anomalies from longer period means pertaining to any required oceanic grid size of interest. The core MATLAB code uses the daily binary files (3-day aggregate values) of global SST data (derived from TRMM/TMI-AQUA/AMSRE satellite sensors) available on near real-time basis through the REMSS/NASA website and converts these SSTs into global/regional maps and displays as well as digitised text data tables for further analysis. As demonstrated applications of the model, the SST data for the period between 2003-2009 has been utilised to study (a) SST anomalies before, during and after the occurrence of two great under-sea earthquakes of 26 December 2004 and 28 March 2005 near the western coast of Sumatra and (b) variation of pixel numbers with SSTs between 27-31° C within (i) Nino 4 region and (ii) a broader western Pacific region (say Nino-BP) affected by ENSO events before (January-May) and during (June-October) Monsoon onset/progress. Preliminary results of these studies have been published (Chakravarty, The Open Oceanography Journal, 2009 and Chakravarty, IEEE Xplore, 2009). The results of the SST-earthquake analysis indicate a small but consistent warming of 0.2-0.3° C in the 2° x2° grid area near the earthquake epicentre starting a week earlier to a week later for the event of 26 December 2004. The changes observed in SST for the second earthquake is also indicated but with less clarity owing to the mixing of land and ocean surfaces and hence less number of SST pixels available within the 2° x 2° grid area near the corresponding epicen-tre. Similar analysis for the same period of non-earthquake years did not show any such SST anomalies. These results have far reaching implications to use SST as a possible parameter to be monitored for signalling occurrence of

  5. 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 .

  6. 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

  7. Poly[[μ-aqua-aqua-[μ(4)-ethyl (dichloro-methyl-ene)diphospho-nato]sesqui-calcium(II)] acetone hemisolvate 4.5-hydrate].

    Science.gov (United States)

    Jokiniemi, Jonna; Peräniemi, Sirpa; Vepsäläinen, Jouko; Ahlgrén, Markku

    2009-03-25

    The title compound, {[Ca(1.5)(C(3)H(5)Cl(2)O(6)P(2))(H(2)O)(2)]·0.5CH(3)COCH(3)·4.5H(2)O}(n), has a two-dimensional polymeric structure. The asymmetric unit contains two crystallographically independent Ca(2+) cations connected by a chelating and bridging ethyl (dichloro-methyl-ene)diphos-pho-n-ate(3(-)) ligand and an aqua ligand. One of the Ca atoms, lying on a centre of symmetry, has a slightly distorted octa-hedral geometry, while the other Ca atom is seven-coordinated in a distorted monocapped trigonal-prismatic geometry. The polymeric layers are further connected by extensive O-H⋯O hydrogen bonding into a three-dimensional supra-molecular network. The acetone solvent mol-ecule and one uncoordin-ated water mol-ecule are located on twofold rotation axes.

  8. 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

  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. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Characterization of a lytic cyanophage that infects the bloom-forming cyanobacterium Aphanizomenon flos-aquae.

    Science.gov (United States)

    Šulčius, Sigitas; Šimoliūnas, Eugenijus; Staniulis, Juozas; Koreivienė, Judita; Baltrušis, Paulius; Meškys, Rolandas; Paškauskas, Ričardas

    2015-02-01

    Vb-AphaS-CL131 is a novel cyanosiphovirus that infects harmful Aphanizomenon flos-aquae. This cyanophage has an isometric head, 97 nm in diameter and a long, flexible non-contractile tail, 361 nm long. With a genome size of ~120 kb, it is the second largest cyanosiphovirus isolated to date. The latent period was estimated to be ~36 h and a single infected cell produces, on average, 218 infectious cyanophages. Cyanophage infection significantly suppresses host biomass production and alters population phenotype.

  15. 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

  16. CERES BiDirectional Scans (BDS) data in HDF (CER_BDS_Aqua-FM3_Edition1-CV)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    Each BiDirectional Scans (BDS) data product contains twenty-four hours of Level-1b data for each CERES scanner instrument mounted on each spacecraft. The BDS includes samples taken in normal and short Earth scan elevation profiles in both fixed and rotating azimuth scan modes (including space, internal calibration, and solar calibration views). The BDS contains Level-0 raw (unconverted) science and instrument data as well as the geolocated converted science and instrument data. The BDS contains additional data not found in the Level-0 input file, including converted satellite position and velocity data, celestial data, converted digital status data, and parameters used in the radiance count conversion equations. The following CERES BDS data sets are currently available: CER_BDS_TRMM-PFM_Edition1 CER_BDS_Terra-FM1_Edition1 CER_BDS_Terra-FM2_Edition1 CER_BDS_Terra-FM1_Edition2 CER_BDS_Terra-FM2_Edition2 CER_BDS_Aqua-FM3_Edition1 CER_BDS_Aqua-FM4_Edition1 CER_BDS_Aqua-FM3_Edition2 CER_BDS_Aqua-FM4_Edition2 CER_BDS_Aqua-FM3_Edition1-CV CER_BDS_Aqua-FM4_Edition1-CV CER_BDS_Terra-FM1_Edition1-CV CER_BDS_Terra-FM2_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2006-11-02] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  17. CERES BiDirectional Scans (BDS) data in HDF (CER_BDS_Aqua-FM4_Edition1)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    Each BiDirectional Scans (BDS) data product contains twenty-four hours of Level-1b data for each CERES scanner instrument mounted on each spacecraft. The BDS includes samples taken in normal and short Earth scan elevation profiles in both fixed and rotating azimuth scan modes (including space, internal calibration, and solar calibration views). The BDS contains Level-0 raw (unconverted) science and instrument data as well as the geolocated converted science and instrument data. The BDS contains additional data not found in the Level-0 input file, including converted satellite position and velocity data, celestial data, converted digital status data, and parameters used in the radiance count conversion equations. The following CERES BDS data sets are currently available: CER_BDS_TRMM-PFM_Edition1 CER_BDS_Terra-FM1_Edition1 CER_BDS_Terra-FM2_Edition1 CER_BDS_Terra-FM1_Edition2 CER_BDS_Terra-FM2_Edition2 CER_BDS_Aqua-FM3_Edition1 CER_BDS_Aqua-FM4_Edition1 CER_BDS_Aqua-FM3_Edition2 CER_BDS_Aqua-FM4_Edition2 CER_BDS_Aqua-FM3_Edition1-CV CER_BDS_Aqua-FM4_Edition1-CV CER_BDS_Terra-FM1_Edition1-CV CER_BDS_Terra-FM2_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2005-04-02] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  18. CERES BiDirectional Scans (BDS) data in HDF (CER_BDS_Aqua-FM3_Edition2)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    Each BiDirectional Scans (BDS) data product contains twenty-four hours of Level-1b data for each CERES scanner instrument mounted on each spacecraft. The BDS includes samples taken in normal and short Earth scan elevation profiles in both fixed and rotating azimuth scan modes (including space, internal calibration, and solar calibration views). The BDS contains Level-0 raw (unconverted) science and instrument data as well as the geolocated converted science and instrument data. The BDS contains additional data not found in the Level-0 input file, including converted satellite position and velocity data, celestial data, converted digital status data, and parameters used in the radiance count conversion equations. The following CERES BDS data sets are currently available: CER_BDS_TRMM-PFM_Edition1 CER_BDS_Terra-FM1_Edition1 CER_BDS_Terra-FM2_Edition1 CER_BDS_Terra-FM1_Edition2 CER_BDS_Terra-FM2_Edition2 CER_BDS_Aqua-FM3_Edition1 CER_BDS_Aqua-FM4_Edition1 CER_BDS_Aqua-FM3_Edition2 CER_BDS_Aqua-FM4_Edition2 CER_BDS_Aqua-FM3_Edition1-CV CER_BDS_Aqua-FM4_Edition1-CV CER_BDS_Terra-FM1_Edition1-CV CER_BDS_Terra-FM2_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2006-01-01] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  19. CERES BiDirectional Scans (BDS) data in HDF (CER_BDS_Aqua-FM4_Edition1-CV)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    Each BiDirectional Scans (BDS) data product contains twenty-four hours of Level-1b data for each CERES scanner instrument mounted on each spacecraft. The BDS includes samples taken in normal and short Earth scan elevation profiles in both fixed and rotating azimuth scan modes (including space, internal calibration, and solar calibration views). The BDS contains Level-0 raw (unconverted) science and instrument data as well as the geolocated converted science and instrument data. The BDS contains additional data not found in the Level-0 input file, including converted satellite position and velocity data, celestial data, converted digital status data, and parameters used in the radiance count conversion equations. The following CERES BDS data sets are currently available: CER_BDS_TRMM-PFM_Edition1 CER_BDS_Terra-FM1_Edition1 CER_BDS_Terra-FM2_Edition1 CER_BDS_Terra-FM1_Edition2 CER_BDS_Terra-FM2_Edition2 CER_BDS_Aqua-FM3_Edition1 CER_BDS_Aqua-FM4_Edition1 CER_BDS_Aqua-FM3_Edition2 CER_BDS_Aqua-FM4_Edition2 CER_BDS_Aqua-FM3_Edition1-CV CER_BDS_Aqua-FM4_Edition1-CV CER_BDS_Terra-FM1_Edition1-CV CER_BDS_Terra-FM2_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2005-03-30] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  20. CERES BiDirectional Scans (BDS) data in HDF (CER_BDS_Aqua-FM3_Edition1)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    Each BiDirectional Scans (BDS) data product contains twenty-four hours of Level-1b data for each CERES scanner instrument mounted on each spacecraft. The BDS includes samples taken in normal and short Earth scan elevation profiles in both fixed and rotating azimuth scan modes (including space, internal calibration, and solar calibration views). The BDS contains Level-0 raw (unconverted) science and instrument data as well as the geolocated converted science and instrument data. The BDS contains additional data not found in the Level-0 input file, including converted satellite position and velocity data, celestial data, converted digital status data, and parameters used in the radiance count conversion equations. The following CERES BDS data sets are currently available: CER_BDS_TRMM-PFM_Edition1 CER_BDS_Terra-FM1_Edition1 CER_BDS_Terra-FM2_Edition1 CER_BDS_Terra-FM1_Edition2 CER_BDS_Terra-FM2_Edition2 CER_BDS_Aqua-FM3_Edition1 CER_BDS_Aqua-FM4_Edition1 CER_BDS_Aqua-FM3_Edition2 CER_BDS_Aqua-FM4_Edition2 CER_BDS_Aqua-FM3_Edition1-CV CER_BDS_Aqua-FM4_Edition1-CV CER_BDS_Terra-FM1_Edition1-CV CER_BDS_Terra-FM2_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2005-11-02] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  1. CERES BiDirectional Scans (BDS) data in HDF (CER_BDS_Aqua-FM4_Edition2)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    Each BiDirectional Scans (BDS) data product contains twenty-four hours of Level-1b data for each CERES scanner instrument mounted on each spacecraft. The BDS includes samples taken in normal and short Earth scan elevation profiles in both fixed and rotating azimuth scan modes (including space, internal calibration, and solar calibration views). The BDS contains Level-0 raw (unconverted) science and instrument data as well as the geolocated converted science and instrument data. The BDS contains additional data not found in the Level-0 input file, including converted satellite position and velocity data, celestial data, converted digital status data, and parameters used in the radiance count conversion equations. The following CERES BDS data sets are currently available: CER_BDS_TRMM-PFM_Edition1 CER_BDS_Terra-FM1_Edition1 CER_BDS_Terra-FM2_Edition1 CER_BDS_Terra-FM1_Edition2 CER_BDS_Terra-FM2_Edition2 CER_BDS_Aqua-FM3_Edition1 CER_BDS_Aqua-FM4_Edition1 CER_BDS_Aqua-FM3_Edition2 CER_BDS_Aqua-FM4_Edition2 CER_BDS_Aqua-FM3_Edition1-CV CER_BDS_Aqua-FM4_Edition1-CV CER_BDS_Terra-FM1_Edition1-CV CER_BDS_Terra-FM2_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2005-03-29] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  2. ELABORATION OF NOT LARGE MOBILE MODULAR INSTALLATION ''AQUA - EXPRESS'' (300 L/H) FOR LRW CLEANING

    Energy Technology Data Exchange (ETDEWEB)

    Karlin, Yurii; Dmitriev, Sergey; Iljin, Vadim; Ojovan, Mihail; Burcl, Rudolf

    2003-02-27

    Mobile modular installation ''Aqua-Express'' is a liquid low level and intermediate level radioactive waste (LL&ILRW) treatment facility, intended for not large research centers and other organizations, which activity causes the formation of a few quantity (up to 500 m3/year) of low and intermediate level radioactive waste water. Mobile modular installation ''Aqua-Express'' has the following features: (1) filtration, sorption and ultrafiltration units are used for LL&ILRW purification; (2) installation ''Aqua-Express'' consists of a cascade of three autonomous aqueous liquid waste-purifying installations; (3) installation ''Aqua-Express'' is a mobile installation; the installation can be transported by car, train, ship, or plane, as well as placed in a standard transport (sea or railway) container; (4) installation ''Aqua-Express'' does not includes any technological equipment for conditioning the secondary radioactive waste. Productivity of the installation ''Aqua-Express'' by purified water depends on composition of the initial liquid waste and makes up to 300 l/h. In present report is described the design of installation ''Aqua-Express'', theory of LRW purification in the installation ''Aqua-Express'' and some results of its use at cleaning real radioactive waters at State unitary enterprise - MosNPO ''Radon''.

  3. 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...

  4. An overview of Aqua MODIS after five-year on-orbit operation and calibration

    Science.gov (United States)

    Barnes, W.; Xiong, X.; Wenny, B.; Xie, X.; Wu, A.; Che, N.; Sun, J.; Salomonson, V.

    2007-10-01

    Launched in May 2002, the Aqua MODIS has successfully operated on-orbit for more than five years and continuously produced many high quality data products that have significantly contributed to studies of the Earth's climate and environmental changes. The MODIS collects data in 36 spectral bands ranging from the visible (VIS) to the long-wave infrared (LWIR) spectral region and at three (nadir) spatial resolutions: 250m (2 bands), 500m (5 bands), and 1km (29 bands). Bands 1-19 and 26 are the reflective solar bands (RSB) with wavelengths from 0.41 to 2.2μm and bands 20-25 and 27-36 are the thermal emissive bands (TEB) with wavelengths from 3.7 to 14.4μm. The MODIS on-board calibrators, noticeably improved over those of its heritage sensors, include a solar diffuser (SD), a solar diffuser stability monitor (SDSM), a blackbody (BB), a spectro-radiometric calibration assembly (SRCA), and a space view (SV) port. This paper provides an overview of Aqua MODIS on-orbit operation and calibration activities with emphasis on the performance of its on-board calibrators. Results discussed in this paper include TEB and RSB detector noise characterization, short-term stability and long-term response change. The sensor's overall spectral (RSB) and spatial (RSB and TEB) parameters are also presented in this paper.

  5. Overview of Aqua MODIS 10-year on-orbit calibration and performance

    Science.gov (United States)

    Xiong, X.; Wenny, B.; Sun, J.; Angal, A.; Wu, A.; Chen, H.; Choi, T.; Madhavan, S.; Geng, X.; Link, D.; Wang, Z.; Toller, G.; Barnes, W.; Salomonson, V.

    2012-09-01

    Since launch in May 2002, Aqua MODIS has successfully operated for over 10 years, continuously collecting global datasets for scientific studies of key parameters of the earth's land, ocean, and atmospheric properties and their changes over time. The quality of these geophysical parameters relies on the input quality of sensor calibrated radiances. MODIS observations are made in 36 spectral bands with wavelengths ranging from visible (VIS) to long-wave infrared (LWIR). Its reflective solar bands (RSB) are calibrated using data collected from its on-board solar diffuser and regularly scheduled lunar views. The thermal emissive bands (TEB) are calibrated using an on-board blackbody (BB). The changes in the sensor's spectral and spatial characteristics are monitored by an on-board spectroradiometric calibration assembly (SRCA). This paper presents an overview of Aqua MODIS 10-year on-orbit operation and calibration activities, from launch to present, and summarizes its on-orbit radiometric, spectral, and spatial calibration and characterization performance. In addition, on-orbit changes in sensor characteristics and corrections applied to continuously maintain level 1B (L1B) data quality are discussed, as well as lessons learned that could benefit future calibration efforts.

  6. Recent progress on cross-comparison of terra and aqua MODIS calibration using Dome C

    Science.gov (United States)

    Xiong, Xiaoxiong; Wu, Aisheng; Angal, Amit; Wenny, Brian

    2009-09-01

    For the past few years, the MODIS Characterization Support Team (MCST) at NASA/GSFC has continued and extended its effort to monitor the Terra and Aqua MODIS calibration long-term stability and to examine their calibration consistency using observations made over the Dome Concordia, Antarctica. Early results from Dome C observations show that the calibration of bands 1 and 2 (0.65 and 0.86 micron) has been consistent within 1-2% and bands 31 and 32 (11 and 12 micron) differences are less than a few tenths of Kelvin, demonstrating that this site can provide a useful calibration reference for a wide range of Earth-observing sensors in the spectral region from visible (VIS) to long-wave infrared (LWIR). Recently, several locations at the Dome C area have been endorsed by the CEOS as radiometric reference sites for sensor cross-comparison. This, as a result, has led to an invitation to the broad earth-observing community to participate in a CEOS comparison of top-of-atmosphere (TOA) spectral radiance/reflectance over the Dome C sites. In this paper, we provide a brief description of the methodologies applied in our study and report recent progress on cross-comparison of Terra and Aqua MODIS spectral bands using observations over the Dome C area, including data provided in support of the upcoming CEOS sensor cross-comparison.

  7. Assessments and applications of Terra and Aqua MODIS on-orbit electronic calibration

    Science.gov (United States)

    Xiong, Xiaoxiong; Chen, Na; Li, Yonghong; Wilson, Truman

    2016-09-01

    MODIS has 36 spectral bands located on four focal plane assemblies (FPAs), covering wavelengths from 0.41 to 14.4 μm. MODIS bands 1-30 collect data using photovoltaic (PV) detectors and, therefore, are referred to as the PV bands. Similarly, bands 31-36 using photoconductive (PC) detectors are referred to as the PC bands. The MODIS instrument was built with a set of on-board calibrators (OBCs) in order to track on-orbit changes of its radiometric, spatial, and spectral characteristics. In addition, an electronic calibration (ECAL) function can be used to monitor on-orbit changes of its electronic responses (gains). This is accomplished via a series of stair step signals generated by the ECAL function. These signals, in place of the FPA detector signals, are amplified and digitized just like the detector signals. Over the entire mission of both Terra and Aqua MODIS, the ECAL has been performed for the PV bands and used to assess their on-orbit performance. This paper provides an overview of MODIS on-orbit calibration activities with a focus on the PV ECAL, including its calibration process and approaches used to monitor the electronic performance. It presents the results derived and lessons learned from Terra and Aqua MODIS on-orbit ECAL. Also discussed are some of the applications performed with the information provided by the ECAL data.

  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. Detection of Terrestrial Ecosystem Disturbances Using Aqua/MODIS Land Surface Temperature and Enhanced Vegetation Index

    Science.gov (United States)

    Mildrexler, D. J.; Zhao, M.; Running, S. W.

    2011-12-01

    Global information on the timing, location and magnitude of large-scale ecosystem disturbance events is needed to reduce significant uncertainty in the global carbon cycle. The MODIS Global Disturbance Index (MGDI) algorithm is designed for systematic, global, disturbance mapping using Aqua/MODIS Land Surface Temperature (LST) and Enhanced Vegetation Index (EVI) data. The MGDI uses annual maximum composite LST data to detect fundamental changes in land-surface energy partitioning, while avoiding the high natural variability associated with tracking LST at daily, weekly, or seasonal time frames. LST and EVI respond to different biophysical processes and coupling these variables together into a ratio results in a dynamic approach that measures both the energy exchange consequence and the vegetation density changes resulting from disturbance. This robust radiometric relationship is revisited for each individual pixel every year resulting in a consistent methodology that can be generalized globally to provide 1-km resolution information about the effects of major disturbance on woody ecosystems and has been validated across North America. We have now applied the full Aqua/MODIS dataset through 2010 to the MGDI algorithm across woody ecosystems globally and continue to validate the MGDI results by comparison with confirmed, historical disturbance events such as wildfire, hurricanes, insect epidemics, ice storms, and droughts.

  10. 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.

  11. De-noising of microwave satellite soil moisture time series

    Science.gov (United States)

    Su, Chun-Hsu; Ryu, Dongryeol; Western, Andrew; Wagner, Wolfgang

    2013-04-01

    The use of satellite soil moisture data for scientific and operational hydrologic, meteorological and climatological applications is advancing rapidly due to increasing capability and temporal coverage of current and future missions. However evaluation studies of various existing remotely-sensed soil moisture products from these space-borne microwave sensors, which include AMSR-E (Advanced Microwave Scanning Radiometer) on Aqua satellite, SMOS (Soil Moisture and Ocean Salinity) mission and ASCAT (Advanced Scatterometer) on MetOp-A satellite, found them to be significantly different from in-situ observations, showing large biases and different dynamic ranges and temporal patterns (e.g., Albergel et al., 2012; Su et al., 2012). Moreover they can have different error profiles in terms of bias, variance and correlations and their performance varies with land surface characteristics (Su et al., 2012). These severely impede the effort to use soil moisture retrievals from multiple sensors concurrently in land surface modelling, cross-validation and multi-satellite blending. The issue of systematic errors present in data sets should be addressed prior to renormalisation of the data for blending and data assimilation. Triple collocation estimation technique has successfully yielded realistic error estimates (Scipal et al., 2008), but this method relies on availability of large number of coincident data from multiple independent satellite data sets. In this work, we propose, i) a conceptual framework for distinguishing systematic periodic errors in the form of false spectral resonances from non-systematic errors (stochastic noise) in remotely-sensed soil moisture data in the frequency domain; and ii) the use of digital filters to reduce the variance- and correlation-related errors in satellite data. In this work, we focus on the VUA-NASA (Vrije Universiteit Amsterdam with NASA) AMSR-E, CATDS (Centre National d'Etudes Spatiales, CNES) SMOS and TUWIEN (Vienna University of

  12. 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

  13. 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

  14. 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

  15. 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.

  16. The combined effects of Dolichospermum flos-aquae, light, and temperature on microcystin production by Microcystis aeruginosa

    Science.gov (United States)

    Chen, Ruoqi; Li, Fangfang; Liu, Jiadong; Zheng, Hongye; Shen, Fei; Xue, Yarong; Liu, Changhong

    2016-11-01

    The effects of light, temperature, and coculture on the intracellular microcystin-LR (MC-LR) quota of Microcystis aeruginosa were evaluated based on coculture experiments with nontoxic Dolichospermum ( Anabaena) flos-aquae. The MC-LR quota and transcription of mcyB and mcyD genes encoding MC synthetases in M. aeruginosa were evaluated on the basis of cell counts, high-performance liquid chromatography, and reverse-transcription quantitative real-time PCR. The MC-LR quotas of M. aeruginosa in coculture with a 1/1 ratio of inoculum of the two species were significantly lower relative to monocultures 6-d after inoculation. Decreased MC-LR quotas under coculture conditions were enhanced by increasing the D. flos-aquae to M. aeruginosa ratio in the inoculum and by environmental factors, such as temperature and light intensity. Moreover, the transcriptional concentrations of mcyB and mcyD genes in M. aeruginosa were significantly inhibited by D. flos-aquae competition in coculture ( P <0.01), lowered to 20% of initial concentrations within 8 days. These data suggested that coculture eff ects by D. flos-aquae not only reduced M. aeruginosa's intracellular MC-LR quota via inhibition of genes encoding MC synthetases, but also that this eff ect was regulated by environmental factors, including temperature and light intensities.

  17. Volatile organic compounds released from Microcystis flos-aquae under nitrogen sources and their toxic effects on Chlorella vulgaris.

    Science.gov (United States)

    Xu, Qinghuan; Yang, Lin; Yang, Wangting; Bai, Yan; Hou, Ping; Zhao, Jingxian; Zhou, Lv; Zuo, Zhaojiang

    2017-01-01

    Eutrophication promotes massive growth of cyanobacteria and algal blooms, which can poison other algae and reduce biodiversity. To investigate the differences in multiple nitrogen (N) sources in eutrophicated water on the emission of volatile organic compounds (VOCs) from cyanobacteria, and their toxic effects on other algal growth, we analyzed VOCs emitted from Microcystis flos-aquae with different types and concentrations of nitrogen, and determined the effects under Normal-N and Non-N conditions on Chlorella vulgaris. M. flos-aquae released 27, 22, 20, 27, 19, 25 and 17 compounds, respectively, with NaNO3, NaNO2, NH4Cl, urea, Ser, Lys and Arg as the sole N source. With the reduction in N amount, the emission of VOCs was increased markedly, and the most VOCs were found under Non-N condition. C. vulgaris cell propagation, photosynthetic pigment and Fv/Fm declined significantly following exposure to M. flos-aquae VOCs under Non-N condition, but not under Normal-N condition. When C. vulgaris cells were treated with two terpenoids, eucalyptol and limonene, the inhibitory effects were enhanced with increasing concentrations. Therefore, multiple N sources in eutrophicated water induce different VOC emissions from cyanobacteria, and reduction in N can cause nutrient competition, which can result in emissions of more VOCs. Those VOCs released from M. flos-aquae cells under Non-N for nutrient competition can inhibit other algal growth. Among those VOCs, eucalyptol and limonene are the major toxic agents.

  18. Respiratory toxicity of cyanobacterial aphantoxins from Aphanizomenon flos-aquae DC-1 in the zebrafish gill

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, De Lu, E-mail: deluzh@163.com [Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070 (China); Liu, Si Yi [Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Jing [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Zhang, Jian Kun [Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070 (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); Liu, Yong Ding [Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China)

    2016-07-15

    Highlights: • Aphantoxin causes physiological and histological changes in zebrafish gills. • Changes in gill enzymes (ALT, AST) and ultrastructure demonstrate injury. • Reduced AChE and MAO activity suggest altered neurotransmitter inactivation. - Abstract: Aphantoxins from Aphanizomenon flos-aquae are frequently identified in eutrophic waterbodies worldwide. These toxins severely endanger environmental safety and human health due to the production of paralytic shellfish poisons (PSPs). Although the molecular mechanisms of aphantoxin neurotoxicity have been studied, many questions remain to be resolved such as in vivo alterations in branchial histology and neurotransmitter inactivation induced by these neurotoxins. Aphantoxins extracted from a naturally isolated strain of A. flos-aquae DC-1 were determined by high performance liquid chromatography. The basic components of the isolated aphantoxins identified were gonyautoxin 1 (GTX1), gonyautoxin 5 (GTX5), and neosaxitoxin (neoSTX), which comprised 34.04, 21.28, and 12.77% of the total, respectively. Zebrafish (Danio rerio) was administrated 5.3 or 7.61 mg STX equivalents (eq)/kg (low and high doses, respectively) of the A. flos-aquae DC-1 aphantoxins by intraperitoneal injection. Histological alterations and changes in neurotransmitter inactivation in the gills of zebrafish were investigated for 24 h following exposure. Aphantoxin exposure significantly increased the activities of gill alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and resulted in histological alterations in the gills during the first 12 h of exposure, indicating the induction of functional and structural damage. Gill acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities were inhibited significantly, suggesting an alteration of neurotransmitter inactivation in zebrafish gills. The observed alterations in gill structure and function followed a time- and dose-dependent pattern. The results demonstrate that

  19. Inferences of all-sky solar irradiance using Terra and Aqua MODIS satellite data

    DEFF Research Database (Denmark)

    Houborg, Rasmus Møller; Søgaard, Henrik; Emmerich, W.

    2007-01-01

    -sky solar irradiance components, which links a physically based clear-sky model with a neural network version of a rigorous radiative transfer model. The scheme exploits the improved cloud characterization and retrieval capabilities of the MODerate resolution Imaging Spectroradiometer (MODIS) onboard...... the Terra and Aqua satellites, and employs a cloud motion tracking scheme for the production of hourly solar irradiance data throughout the day. The scheme was implemented for the Island of Zealand, Denmark (56° N, 12° E) and Southern Arizona, USA (31° N, 110° W) permitting model evaluation for two highly...... contrasting climates and cloud environments. Information on the atmospheric state was provided by MODIS data products and verifications against AErosol RObotic NETwork (AERONET) data demonstrated usefulness of MODIS aerosol optical depth and total precipitable water vapour retrievals for the delineation...

  20. Recovery of gold from computer circuit board scrap using aqua regia.

    Science.gov (United States)

    Sheng, Peter P; Etsell, Thomas H

    2007-08-01

    Computer circuit board scrap was first treated with one part concentrated nitric acid and two parts water at 70 degrees C for 1 h. This step dissolved the base metals, thereby liberating the chips from the boards. After solid-liquid separation, the chips, intermixed with some metallic flakes and tin oxide precipitate, were mechanically crushed to liberate the base and precious metals contained within the protective plastic or ceramic chip cases. The base metals in this crushed product were dissolved by leaching again with the same type of nitric acid-water solution. The remaining solid constituents, crushed chips and resin, plus solid particles of gold, were leached with aqua regia at various times and temperatures. Gold was precipitated from the leachate with ferrous sulphate.

  1. Optimizing Aqua Splicer Parameters for Lycra-Cotton Core Spun Yarn Using Taguchi Method

    Science.gov (United States)

    Midha, Vinay Kumar; Hiremath, ShivKumar; Gupta, Vaibhav

    2015-10-01

    In this paper, optimization of the aqua splicer parameters viz opening time, splicing time, feed arm code (i.e. splice length) and duration of water joining was carried out for 37 tex lycra-cotton core spun yarn for better retained splice strength (RSS%), splice abrasion resistance (RYAR%) and splice appearance (RYA%) using Taguchi experimental design. It is observed that as opening time, splicing time and duration of water joining increase, the RSS% and RYAR% increases, whereas increase in feed arm code leads to decrease in both. The opening time and feed arm code do not have significant effect on RYA%. The optimum RSS% of 92.02 % was obtained at splicing parameters of 350 ms opening time, 180 ms splicing time, 65 feed arm code and 600 ms duration of water joining.

  2. Purification and characterization of phycocyanin from the blue-green alga Aphanizomenon flos-aquae.

    Science.gov (United States)

    Benedetti, Serena; Rinalducci, Sara; Benvenuti, Francesca; Francogli, Sonia; Pagliarani, Silvia; Giorgi, Luca; Micheloni, Mauro; D'Amici, Gian Maria; Zolla, Lello; Canestrari, Franco

    2006-03-20

    Aphanizomenon flos-aquae (AFA) is a blue-green alga and represents a nutrient-dense food source. In this study the presence of phycocyanin (PC), a blue protein belonging to the photosynthetic apparatus, has been demonstrated in AFA. An efficient method for its separation has been set up: PC can be purified by a simple single step chromatographic run using a hydroxyapatite column (ratio A620/A280 of 4.78), allowing its usage for health-enhancing properties while eliminating other aspecific algal components. Proteomic investigation and HPLC analysis of purified AFA phycobilisomes revealed that, contrary to the well-characterized Synechocystis and Spirulina spp., only one type of biliprotein is present in phycobilisomes: phycocyanins with no allo-phycocyanins. Two subunit polypeptides of PC were also separated: the beta subunit containing two bilins as chromophore and the alpha subunit containing only one.

  3. Statistical Analysis of Deflation in Covariance and Resultant Pc Values for AQUA, AURA and TERRA

    Science.gov (United States)

    Hasan, Syed O.

    2016-01-01

    This presentation will display statistical analysis performed for raw conjunction CDMs received for the EOS Aqua, Aura and Terra satellites within the period of February 2015 through July 2016. The analysis performed indicates a discernable deflation in covariance calculated at the JSpOC after the utilization of the dynamic drag consider parameter was implemented operationally in May 2015. As a result, the overall diminution in the conjunction plane intersection of the primary and secondary objects appears to be leading to reduced probability of collision (Pc) values for these conjunction events. This presentation also displays evidence for this theory with analysis of Pc trending plots using data calculated by the SpaceNav CRMS system.

  4. 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.

  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. 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.

  7. 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.

  8. Application of satellite microwave remote sensed brightness temperature in the regional soil moisture simulation

    Directory of Open Access Journals (Sweden)

    X. K. Shi

    2009-02-01

    Full Text Available As the satellite microwave remote sensed brightness temperature is sensitive to land surface soil moisture (SM and SM is a basic output variable in model simulation, it is of great significance to use the brightness temperature data to improve SM numerical simulation. In this paper, the theory developed by Yan et al. (2004 about the relationship between satellite microwave remote sensing polarization index and SM was used to estimate the land surface SM from AMSR-E (Advanced Microwave Scanning Radiometer – Earth Observing System brightness temperature data. With consideration of land surface soil texture, surface roughness, vegetation optical thickness, and the AMSR-E monthly SM products, the regional daily land surface SM was estimated over the eastern part of the Qinghai-Tibet Plateau. The results show that the estimated SM is lower than the ground measurements and the NCEP (American National Centers for Environmental Prediction reanalysis data at the Maqu Station (33.85° N, 102.57° E and the Tanglha Station (33.07° N, 91.94° E, but its regional distribution is reasonable and somewhat better than that from the daily AMSR-E SM product, and its temporal variation shows a quick response to the ground daily precipitations. Furthermore, in order to improve the simulating ability of the WRF (Weather Research and Forecasting model to land surface SM, the estimated SM was assimilated into the Noah land surface model by the Newtonian relaxation (NR method. The results indicate that, by fine tuning of the quality factor in NR method, the simulated SM values are improved most in desert area, followed by grassland, shrub and grass mixed zone. At temporal scale, Root Mean Square Error (RMSE values between simulated and observed SM are decreased 0.03 and 0.07 m3/m3 by using the NR method in the Maqu Station and the Tanglha Station, respectively.

  9. 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.

  10. Floods, floodplains, delta plains — A satellite imaging approach

    Science.gov (United States)

    Syvitski, James P. M.; Overeem, Irina; Brakenridge, G. Robert; Hannon, Mark

    2012-08-01

    Thirty-three lowland floodplains and their associated delta plains are characterized with data from three remote sensing systems (AMSR-E, SRTM and MODIS). These data provide new quantitative information to characterize Late Quaternary floodplain landscapes and their penchant for flooding over the last decade. Daily proxy records for discharge since 2002 and for each of the 33 river systems can be derived with novel Advanced Microwave Scanning Radiometer (AMSR-E) methods. A descriptive framework based on analysis of Shuttle Radar Topography Mission (SRTM) data is used to capture the major landscape-scale floodplain elements or zones: 1) container valleys with their long and narrow pathways of largely sediment transit and bypass, 2) floodplain depressions that act as loci for frequent flooding and sediment storage, 3) zones of nodal avulsions common to many continental scale rivers, and often located seaward of container valleys, and 4) coastal floodplains and delta plains that offer both sediment bypass and storage but under the influence of marine processes. The SRTM data allow mapping of smaller-scale architectural elements in unprecedented systematic manner. Floodplain depressions were found to play a major role, which may largely be overlooked in conceptual floodplain models. Lastly, MODIS data (independently and combined with AMSR-E) allows the tracking of flood hydrographs and pathways and sedimentation patterns on a near-daily timescale worldwide. These remote-sensing data show that 85% of the studied major river systems experienced extensive flooding in the last decade. A new quantitative paradigm of floodplain processes, honoring the frequency and extent of floods, can be develop by careful analysis of these new remotely sensed data.

  11. Contributions of Precipitation and Soil Moisture Observations to the Skill of Soil Moisture Estimates in a Land Data Assimilation System

    Science.gov (United States)

    Reichle, Rolf H.; Liu, Qing; Bindlish, Rajat; Cosh, Michael H.; Crow, Wade T.; deJeu, Richard; DeLannoy, Gabrielle J. M.; Huffman, George J.; Jackson, Thomas J.

    2011-01-01

    The contributions of precipitation and soil moisture observations to the skill of soil moisture estimates from a land data assimilation system are assessed. Relative to baseline estimates from the Modern Era Retrospective-analysis for Research and Applications (MERRA), the study investigates soil moisture skill derived from (i) model forcing corrections based on large-scale, gauge- and satellite-based precipitation observations and (ii) assimilation of surface soil moisture retrievals from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E). Soil moisture skill is measured against in situ observations in the continental United States at 44 single-profile sites within the Soil Climate Analysis Network (SCAN) for which skillful AMSR-E retrievals are available and at four CalVal watersheds with high-quality distributed sensor networks that measure soil moisture at the scale of land model and satellite estimates. The average skill (in terms of the anomaly time series correlation coefficient R) of AMSR-E retrievals is R=0.39 versus SCAN and R=0.53 versus CalVal measurements. The skill of MERRA surface and root-zone soil moisture is R=0.42 and R=0.46, respectively, versus SCAN measurements, and MERRA surface moisture skill is R=0.56 versus CalVal measurements. Adding information from either precipitation observations or soil moisture retrievals increases surface soil moisture skill levels by IDDeltaR=0.06-0.08, and root zone soil moisture skill levels by DeltaR=0.05-0.07. Adding information from both sources increases surface soil moisture skill levels by DeltaR=0.13, and root zone soil moisture skill by DeltaR=0.11, demonstrating that precipitation corrections and assimilation of satellite soil moisture retrievals contribute similar and largely independent amounts of information.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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 ethanol yields as a simulation study at Goodwell, Oklahoma. The corn, forage sorghum and switchgrass were simulated using 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

  17. 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.

  18. 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.

  19. Modeling of Microwave Emissions from the Marie-Byrd Antarctic Region: A Stable Calibration Target in the L-band

    Science.gov (United States)

    Misra, S.; Brown, S.

    2010-12-01

    With the recent launch of SMOS (Soil Moisture Ocean Salinity) and upcoming missions Aquarius and SMAP (Soil Moisture Active Passive), calibration in L-band has become an important issue. The Aquarius mission, due to be launched in April 2011, is responsible for globally mapping sea-surface salinity. Due to the high sensitivity of brightness temperature to salinity and high precision of the Aquarius radiometers, it is necessary to have temporally stable calibration sources. Previously, Dome-C in the east Antarctic region was suggested as a promising area to monitor radiometer calibrations in the L-band toward the hot end of the brightness temperature spectrum (Macelloni et al., 2006; Macelloni et al., 2007). We present the Marie-Byrd region in west Antarctica as an excellent calibration reference, due to both its temporal stability over years as well as spatial vastness. In order to identify stable calibration regions for L-band we used 6-37GHz AMSR-E data. The spatial and temporal variability of AMSR-E brightness temperatures over the Antarctic region was analyzed, and only regions that were stable in both domains (like Marie-Byrd) were identified as radiometrically stable. Using data obtained from Automatic Weather Stations (AWS) near Marie-Byrd, the correlation between surface temperature and deep-ice temperature, as measured by microwaves was calculated. Results indicate that as the microwave frequency is lowered, the peak-to-peak annual variation of brightness temperature decreases. The bulk of emission for low frequencies occurs deep in the ice which is very stable over time and decorrelated with short term surface temperature fluctuations. As a result, at L-band the ice-regions like Marie-Byrd in Antarctica serve as an excellent source of calibration. A coupled ice heat-transport and radiative-transfer model was developed to predict brightness temperatures observed at low microwave frequencies. The ice model takes into account the surface fluctuations of

  20. 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...

  1. 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.

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  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. 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...

  8. 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...

  9. 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...

  10. Effect of aqua-cycling on pain and physical functioning compared with usual care in patients with knee osteoarthritis: study protocol of a randomised controlled trial

    OpenAIRE

    Rewald, Stefanie; Mesters, Ilse; Lenssen, A.F.; Emans, Pieter J.; Wijnen, Wiel; de Bie, Rob A.

    2016-01-01

    Background Over the last decade aquatic exercise has become more and more popular. One of the latest trends is aqua-cycling, where participants sit on a water-resistant stationary bike and, while immersed chest deep in the water, combine continuous cycling with upper body exercises that utilise water resistance. Since stationary cycling and aquatic exercises are frequently recommended to patients with knee osteoarthritis, combining both would seem an obvious step, and an aqua-cycling exercise...

  11. Numerical simulation study of polar lows in Russian Arctic: dynamical characteristics

    Science.gov (United States)

    Verezemskaya, Polina; Baranyuk, Anastasia; Stepanenko, Victor

    2015-04-01

    Polar Lows (hereafter PL) are intensive mesoscale cyclones, appearing above the sea surface, usually behind the arctic front and characterized by severe weather conditions [1]. All in consequence of the global warming PLs started to emerge in the arctic water area as well - in summer and autumn. The research goal is to examine PLs by considering multisensory data and the resulting numerical mesoscale model. The main purpose was to realize which conditions induce PL development in such thermodynamically unusual season and region as Kara sea. In order to conduct the analysis we used visible and infrared images from MODIS (Aqua). Atmospheric water vapor V, cloud liquid water Q content and surface wind fields W were resampled by examining AMSR-E microwave radiometer data (Aqua)[2], the last one was additionally extracted from QuickSCAT scatterometer. We have selected some PL cases in Kara sea, appeared in autumn of 2007-2008. Life span of the PL was between 24 to 36 hours. Vortexes' characteristics were: W from 15m/s, Q and V values: 0.08-0.11 kg/m2 and 8-15 kg/m2 relatively. Numerical experiments were carried out with Weather Research and Forecasting model (WRF), which was installed on supercomputer "Lomonosov" of Research Computing Center of Moscow State University [3]. As initial conditions was used reanalysis data ERA-Interim from European Centre for Medium-Range Weather Forecasts. Numerical experiments were made with 5 km spatial resolution, with Goddard center microphysical parameterization and explicit convection simulation. Modeling fields were compared with satellite observations and shown good accordance. Than dynamic characteristics were analyzed: evolution of potential and absolute vorticity [4], surface heat and momentum fluxes, and CAPE and WISHE mechanisms realization. 1. Polar lows, J. Turner, E.A. Rasmussen, 612, Cambridge University press, Cambridge, 2003. 2. Zabolotskikh, E. V., Mitnik, L. M., & Chapron, B. (2013). New approach for severe marine

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

    Energy Technology Data Exchange (ETDEWEB)

    Tumuluru, Jaya

    2013-01-10

    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

  13. 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%

  14. AquaTrace” The development of tools for tracing and evaluating the genetic impact of fish from aquaculture

    DEFF Research Database (Denmark)

    Eg Nielsen, Einar; Bekkevold, Dorte; Svåsand, Terje

    2012-01-01

    Atlantic salmon and brown trout as model species. Thus, the scientific objectives of AquaTrace are to address and assess the genetic impact of aquaculture escapees introducing genes to wild populations that have been undergoing adaptation to farmed conditions through breeding and domestication selection...... and farming technologies which are economically viable, environmentally friendly, and perceived as socially acceptable. Here we present the objectives, implementation, and potential impact of a new EU FP7 project. The rationale behind AquaTrace is development of reliable and cost‐effective molecular tools...... to identify of the genetic origin of both wild and farmed fish (assignment and genetic traceability), as well as for the detection of interbreeding genetic introgression between farmed and wild stocks. This work will be carried out on three marine fish of economic significance: the European sea bass...

  15. 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

  16. 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

    results show that for the geographical, atmospheric and optical conditions of Lake Tanganyika: (i) a coastal aerosol model set with high relative humidity (90%) provides a suitable atmospheric correction; (ii) a significant correlation between in situ data and CHL estimates using the MODIS specific OC3......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...

  17. 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

  18. 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.

  19. Optimisation of Lime-Soda process parameters for reduction of hardness in aqua-hatchery practices using Taguchi methods.

    Science.gov (United States)

    Yavalkar, S P; Bhole, A G; Babu, P V Vijay; Prakash, Chandra

    2012-04-01

    This paper presents the optimisation of Lime-Soda process parameters for the reduction of hardness in aqua-hatchery practices in the context of M. rosenbergii. The fresh water in the development of fisheries needs to be of suitable quality. Lack of desirable quality in available fresh water is generally the confronting restraint. On the Indian subcontinent, groundwater is the only source of raw water, having varying degree of hardness and thus is unsuitable for the fresh water prawn hatchery practices (M. rosenbergii). In order to make use of hard water in the context of aqua-hatchery, Lime-Soda process has been recommended. The efficacy of the various process parameters like lime, soda ash and detention time, on the reduction of hardness needs to be examined. This paper proposes to determine the parameter settings for the CIFE well water, which is pretty hard by using Taguchi experimental design method. Orthogonal Arrays of Taguchi, Signal-to-Noise Ratio, the analysis of variance (ANOVA) have been applied to determine their dosage and analysed for their effect on hardness reduction. The tests carried out with optimal levels of Lime-Soda process parameters confirmed the efficacy of the Taguchi optimisation method. Emphasis has been placed on optimisation of chemical doses required to reduce the total hardness using Taguchi method and ANOVA, to suit the available raw water quality for aqua-hatchery practices, especially for fresh water prawn M. rosenbergii.

  20. Assessment of FAO AquaCrop Model for Simulating Maize Growth and Productivity under Deficit Irrigation in a Tropical Environment

    Directory of Open Access Journals (Sweden)

    Geneille E. Greaves

    2016-11-01

    Full Text Available Crop simulation models have a pivotal role to play in evaluating irrigation management strategies for improving agricultural water use. The objective of this study was to test and validate the AquaCrop model for maize under deficit irrigation management. Field observations from three experiments consisting of four treatments were used to evaluate model performance in simulating canopy cover (CC, biomass (B, yield (Y, crop evapotranspiration (ETc, and water use efficiency (WUE. Statistics for root mean square error, model efficiency (E, and index of agreement for B and CC suggest that the model prediction is good under non-stressed and moderate stress environments. Prediction of final B and Y under these conditions was acceptable, as indicated by the high coefficient of determination and deviations <10%. In severely stressed conditions, low E and deviations >11% for B and 9% for Y indicate a reduction in the model reliability. Simulated ETc and WUE deviation from observed values were within the range of 9.5% to 22.2% and 6.0% to 32.2%, respectively, suggesting that AquaCrop prediction of these variables is fair, becoming unsatisfactory as plant water stress intensifies. AquaCrop can be reliably used for evaluating the effectiveness of proposed irrigation management strategies for maize; however, the limitations should be kept in mind when interpreting the results in severely stressed conditions.

  1. 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.

  2. Modeling culture profiles of the heterocystous N2-fixing cyanobacterium Anabaena flos-aquae.

    Science.gov (United States)

    Pinzon, Neissa M; Ju, Lu-Kwang

    2006-01-01

    Heterocyst differentiation is a unique feature of nitrogen-fixing cyanobacteria, potentially important for photobiological hydrogen production. Despite the significant advances in genetic investigation on heterocyst differentiation, there were no quantitative culture-level models that describe the effects of cellular activities and cultivation conditions on the heterocyst differentiation. Such a model was developed in this study, incorporating photosynthetic growth of vegetative cells, heterocyst differentiation, self-shading effect on light penetration, and nitrogen fixation. The model parameters were determined by fitting experimental results from the growth of the heterocystous cyanobacterium Anabaena flos-aquae CCAP 1403/13f in media without and with different nitrate concentrations and under continuous illumination of white light at different light intensities (2, 5, 10, 17, 20 and 50 microE m-2 s-1). The model describes the experimental profiles well and gives reasonable predictions even for the transition of growth from that on external N source to that via nitrogen fixation, responding to the change in external N concentrations. The significance and implications of the best-fit values of the model parameters are discussed.

  3. 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.

  4. 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.

  5. Coupling LMDZ physics in WRF model: Aqua-planet configuration tests

    Science.gov (United States)

    Fita, Lluís; Hourdin, Frédéric; Fairhead, Laurent; Drobinski, Phlippe

    2014-05-01

    Nowadays advances in climatological sciences, pose different challenges for the current global climate models (GCM). One of them is related to the resolution. In some exercises, GCMs are started to be used to that resolutions to which they were not designed for, or in advance of future uses, they have to be tested in order to know their limitations. With the mid term perspective in mind of future uses of the Laboratorie de Météorologie Dynamique Zoom (LMDZ) model, a framework has been designed in order to use the physical parameterizations of the LMDZ model coupled to the dynamical core of Weather Research and Forecasting (WRF) model. This framework will allow the analysis of different aspects such as: resolution thresholds of the LMDZ physics set, skill of LMDZ physics in comparison with cloud resolving simulations, impact of the primitive equations fully compressible dynamics from WRF in global runs among others. The design and implementation of the framework keeps almost all the original capabilities of both models. As a first step, results of an ensemble of 1-year low-resolution global aqua-planet runs performed with the original models using different physical configurations, and the new framework will be presented. These initial results show the correct performance of the new framework, and the sensitivity of the global circulation due to different dynamical atmospheric cores and physical parameterizations.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Snail shell as coagulant aid in the alum precipitation of malachite green from aqua system

    Energy Technology Data Exchange (ETDEWEB)

    Oladoja, Nurudeen A., E-mail: bioladoja@yahoo.com [Department of Chemistry, Adekunle Ajasin University, Akungba-Akoko (Nigeria); Aliu, Yekini D. [Department of Chemistry, Adekunle Ajasin University, Akungba-Akoko (Nigeria)

    2009-05-30

    The ability of snail shell (SS) to act as coagulant aid in the alum precipitation of a basic dye (MG) was investigated. The proximate physicochemical characterization of the SS showed the pH{sub solution} to be 8.01, high fraction of the inorganic constituents (ash content = 93.76%), the presence of Ca{sup 2+} (99.74%) as the major metal ion present and the point zero charge (PZC) found at pH 7.9. The X-ray diffractometric analysis revealed the presence of aragonite. The stability and leaching of the SS, tested in different aqua medium (acidic, basic and neutral solutions) showed that the SS was less stable in the acidic medium. Both the alum and the SS were used, differently, for the dye precipitation. The alum alone had no precipitating effect on the MG dye molecules while SS alone was able to reduce the intensity of the dye. When the SS was used as coagulant aid in alum precipitation, the percentage of the MG molecule removed was enhanced. The effects of some process variables (coagulant/coagulant aid dosage, pH and flocculation time) were optimized by method of continuous variation. The optimum pH for the MG removal was found to range between 4 and 5 but the amount of MG removed was appreciable at all the pH studied. Studies on the effect of time on the flocculation of the precipitated MG molecule showed that the problem of redispersion and restabilisation encountered in alum precipitation could be overcome using alum-SS combination. The settling characteristics of the sludge obtained from the use of SS alone and alum-SS combination was studied by measuring the sludge volume index (SVI, mg/g) over time. The value of the SVI (mg/g) showed that the sludge produced from the alum-SS combination had better settling characteristics than the sludge got from the use of SS alone.

  12. 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

  13. 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

  14. 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

  15. 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.

  16. Finland Validation of the New Blended Snow Product

    Science.gov (United States)

    Kim, E. J.; Casey, K. A.; Hallikainen, M. T.; Foster, J. L.; Hall, D. K.; Riggs, G. A.

    2008-01-01

    As part of an ongoing effort to validate satellite remote sensing snow products for the recentlydeveloped U.S. Air Force Weather Agency (AFWA) - NASA blended snow product, Satellite and in-situ data for snow extent and snow water equivalent (SWE) are evaluated in Finland for the 2006-2007 snow season Finnish Meteorological Institute (FMI) daily weather station data and Finnish Environment Institute (SYKE) bi-monthly snow course data are used as ground truth. Initial comparison results display positive agreement between the AFWA NASA Snow Algorithm (ANSA) snow extent and SWE maps and in situ data, with discrepancies in accordance with known AMSR-E and MODIS snow mapping limitations. Future ANSA product improvement plans include additional validation and inclusion of fractional snow cover in the ANSA data product. Furthermore, the AMSR-E 19 GHz (horizontal channel) with the difference between ascending and descending satellite passes (Diurnal Amplitude Variations, DAV) will be used to detect the onset of melt, and QuikSCAT scatterometer data (14 GHz) will be used to map areas of actively melting snow.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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。

  3. 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

  4. Comparison of Terra and Aqua MODIS VIS Bands On-Orbit Response

    Science.gov (United States)

    Xiong, Xiaoxiong; Sun, J.; Che, N.; Choi, T.; Angal, A.

    2008-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) has 36 spectral bands with a total of 490 detectors, covering spectral regions in the visible (VIS), near-infrared (NIR), short-wave infrared (SWIR), mid-wave infrared (MWIR), and long-wave infrared (LWIR). MODIS is a cross-track scanning radiometer which collects data using a rotating scan mirror (both sides) over a wide range of scan angles. The VIS, NIR, and SWIR bands (bands 1-19 and 26) make measurements of daytime surface reflected radiances, thus are referred to as the reflective solar bands (RSB). MODIS was built with a complete set of on-board calibrators, capable of providing radiometric, spatial, and spectral calibration and characterization during its entire mission. The RSB on-orbit calibration is primarily provided using a solar diffuser (SD) and a solar diffuser stability monitor (SDSM). The SD and SDSM calibration system is operated on a regular (weekly to bi-weekly) basis. The spectro-radiometric calibration assembly (SRCA) is another on-hoard calibrator that also provides RSB radiometric calibration support. For this purpose, the SRCA is operated in a radiometric mode on a monthly basis. A complete SRCA radiometric calibration is performed using different lamp configurations, or different radiance levels, to cover the range of RSB gain. Two additional SRCA modes with slightly different configurations are designed and operated for sensor on-orbit spectral and spatial characterization. In addition to its on-hoard calibrators, each MODIS makes monthly lunar observations to monitor RSB radiometric calibration stability. The MODIS lunar observations are made through its space view (SV) port at nearly the same lunar phase angles via spacecraft roll maneuvers. The SD, SRCA, and lunar measurements are made at different scan angles and data samples are collected for all spectral bands and detectors using both sides of the scan minor. Since launch, Terra and Aqua MODIS have operated successfully for

  5. Stratospheric gravity waves at Southern Hemisphere orographic hotspots: 2003-2014 AIRS/Aqua observations

    Science.gov (United States)

    Hoffmann, Lars; Grimsdell, Alison W.; Alexander, M. Joan

    2016-07-01

    Stratospheric gravity waves from small-scale orographic sources are currently not well-represented in general circulation models. This may be a reason why many simulations have difficulty reproducing the dynamical behavior of the Southern Hemisphere polar vortex in a realistic manner. Here we discuss a 12-year record (2003-2014) of stratospheric gravity wave activity at Southern Hemisphere orographic hotspots as observed by the Atmospheric InfraRed Sounder (AIRS) aboard the National Aeronautics and Space Administration's (NASA) Aqua satellite. We introduce a simple and effective approach, referred to as the "two-box method", to detect gravity wave activity from infrared nadir sounder measurements and to discriminate between gravity waves from orographic and other sources. From austral mid-fall to mid-spring (April-October) the contributions of orographic sources to the observed gravity wave occurrence frequencies were found to be largest for the Andes (90 %), followed by the Antarctic Peninsula (76 %), Kerguelen Islands (73 %), Tasmania (70 %), New Zealand (67 %), Heard Island (60 %), and other hotspots (24-54 %). Mountain wave activity was found to be closely correlated with peak terrain altitudes, and with zonal winds in the lower troposphere and mid-stratosphere. We propose a simple model to predict the occurrence of mountain wave events in the AIRS observations using zonal wind thresholds at 3 and 750 hPa. The model has significant predictive skill for hotspots where gravity wave activity is primarily due to orographic sources. It typically reproduces seasonal variations of the mountain wave occurrence frequencies at the Antarctic Peninsula and Kerguelen Islands from near zero to over 60 % with mean absolute errors of 4-5 percentage points. The prediction model can be used to disentangle upper level wind effects on observed occurrence frequencies from low-level source and other influences. The data and methods presented here can help to identify interesting

  6. Effects of chitosan, gallic acid, and algicide on the physiological and biochemical properties of Microcystis flos-aquae.

    Science.gov (United States)

    Guo, Peiyong; Liu, Yang; Liu, Cong

    2015-09-01

    The effects of chitosan, gallic acid, and algicide chitosan-gallate on the activities of antioxidant enzymes, malonaldehyde (MDA) content, and photosynthetic activity of Microcystis flos-aquae were investigated to explore the physiological and biochemical mechanisms of algicides. Results demonstrated that chitosan did not significantly affect catalase (CAT) and superoxide dismutase (SOD) activities, MDA content, and photosynthetic activity in this alga. At 30 mg L(-1), gallic acid, CAT, and SOD activities and MDA of M. flos-aquae cells showed maximums of 2.872 × 10(-10) mg·cell(-1) min(-1), 0.787 × 10(-8) U·cell(-1), and 0.626 × 10(-8) nmol·cell(-1), respectively. Photosynthetic organs in algal cells were severely damaged under the stress of high gallic acid concentrations, inducing blockage of photosynthetic electron transport and resulting in the inability to restore normal photosynthetic activity. CAT and SOD activities and MDA content with lower algicide concentration were significantly higher than the control group (p gallic acid in groups treated with 60, 90, and 130 mg/L algicide was strong enough to cause severe damage to photosynthetic organs in these algal cells. The algicide suppression time was longer than that of directly added gallic acid.

  7. 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.

  8. 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.

  9. Response of cellular stoichiometry and phosphorus storage of the cyanobacteria Aphanizomenon flos-aquae to small-scale turbulence

    Science.gov (United States)

    Li, Zhe; Xiao, Yan; Yang, Jixiang; Li, Chao; Gao, Xia; Guo, Jinsong

    2017-01-01

    Turbulent mixing, in particular on a small scale, affects the growth of microalgae by changing diffusive sublayers and regulating nutrient fluxes of cells. We tested the nutrient flux hypothesis by evaluating the cellular stoichiometry and phosphorus storage of microalgae under different turbulent mixing conditions. Aphanizomenon flos-aquae were cultivated in different stirring batch reactors with turbulent dissipation rates ranging from 0.001 51 m2/s3 to 0.050 58 m2/s3, the latter being the highest range observed in natural aquatic systems. Samples were taken in the exponential growth phase and compared with samples taken when the reactor was completely stagnant. Results indicate that, within a certain range, turbulent mixing stimulates the growth of A. flos-aquae. An inhibitory effect on growth rate was observed at the higher range. Photosynthesis activity, in terms of maximum effective quantum yield of PSII (the ratio of F v/F m) and cellular chlorophyll a, did not change significantly in response to turbulence. However, Chl a/C mass ratio and C/N molar ratio, showed a unimodal response under a gradient of turbulent mixing, similar to growth rate. Moreover, we found that increases in turbulent mixing might stimulate respiration rates, which might lead to the use of polyphosphate for the synthesis of cellular constituents. More research is required to test and verify the hypothesis that turbulent mixing changes the diffusive sublayer, regulating the nutrient flux of cells.

  10. 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.

  11. 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

  12. The regime of aerosol optical depth over Central Asia based on MODIS Aqua Deep Blue data

    Science.gov (United States)

    Floutsi, Athina; KorrasCarraca, Marios; Matsoukas, Christos; Biskos, George

    2015-04-01

    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 therefore important to determine the aerosol load, and an effective way to do that is by measuring the aerosol optical depth (AOD). In this study we investigate the spatial and temporal variability of the AOD over the climatically sensitive region of Central Asia (36° N - 50° N, 46° E - 75° E), which has significant sources of both natural and anthropogenic particles. The primary source of anthropogenic particles is fossil fuel combustion occurring mainly at oil refineries in the Caspian Sea basin. Natural particles originate mostly from the two deserts in the region (namely Kara-Kum and Kyzyl-Kum), where persistent dust activity is observed. Another source is the Aral Sea region, which due to its phenomenal desertification also drives an intense salt and dust transport from the exposed sea-bed to the surrounding regions. This transport is of particular interest because of health-hazardous materials contained in the Aral Sea sea-bed. For our analysis we use Level-3 daily MODIS - Aqua Dark Target - Deep Blue combined product, from the latest MODIS collection (006), available in 1° x 1° resolution (about 100 km x 100 km) over the period 2002-2014.Our first results indicate a significant spatial variability of the aerosol load over the study region. The data also show a clear seasonal cycle, with large aerosol load being associated with strong dust activity during spring and summer (AOD up to 0.5), and low during autumn and winter (AOD up to 0.4). In spring and summer significant aerosol load is observed in the Garabogazköl basin, Northeast and South-southeast Caspian Sea (offshore North Iran and Azerbaijan), as well as southwest of the Aral Sea. In the later region, the high AOD values can be explained by export of

  13. Satellite Gravimetry Applied to Drought Monitoring

    Science.gov (United States)

    Rodell, Matthew

    2010-01-01

    Near-surface wetness conditions change rapidly with the weather, which limits their usefulness as drought indicators. Deeper stores of water, including root-zone soil wetness and groundwater, portend longer-term weather trends and climate variations, thus they are well suited for quantifying droughts. However, the existing in situ networks for monitoring these variables suffer from significant discontinuities (short records and spatial undersampling), as well as the inherent human and mechanical errors associated with the soil moisture and groundwater observation. Remote sensing is a promising alternative, but standard remote sensors, which measure various wavelengths of light emitted or reflected from Earth's surface and atmosphere, can only directly detect wetness conditions within the first few centimeters of the land s surface. Such sensors include the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) C-band passive microwave measurement system on the National Aeronautic and Space Administration's (NASA) Aqua satellite, and the combined active and passive L-band microwave system currently under development for NASA's planned Soil Moisture Active Passive (SMAP) satellite mission. These instruments are sensitive to water as deep as the top 2 cm and 5 cm of the soil column, respectively, with the specific depth depending on vegetation cover. Thermal infrared (TIR) imaging has been used to infer water stored in the full root zone, with limitations: auxiliary information including soil grain size is required, the TIR temperature versus soil water content curve becomes flat as wetness increases, and dense vegetation and cloud cover impede measurement. Numerical models of land surface hydrology are another potential solution, but the quality of output from such models is limited by errors in the input data and tradeoffs between model realism and computational efficiency. This chapter is divided into eight sections, the next of which describes

  14. Complex land surface phenologies of moisture status

    Science.gov (United States)

    Henebry, G. M.; Doubkova, M.

    2006-12-01

    Making cross-scale linkages from experimental plots or flux tower footprints to regional and continental extents is made difficult by disparate spatial and temporal scales between process and observation. While exchanges between the vegetated land surface and the atmospheric boundary layer are continual, sampling and observations are typically intermittent in time and limited across space. Remote sensing of reflected sunlight has proven useful to track ecological dynamics. These observations are, however, restricted to daytime and often obscured by cloud cover, necessitating production of multi-date composites. The current generation of passive microwave radiometers can observe the land surface both day and night regardless of cloudiness, albeit at a spatial resolution coarser than typically used in ecological remote sensing. Datastreams from the AMSR-E (Advanced Microwave Scanning Radiometer-EOS) onboard NASA's Aqua platform are processed daily at the National Snow and Ice Data Center (NSIDC) into various products, including global retrievals of surficial soil moisture and vegetation water content based on microwave brightness temperatures observed at multiple frequencies. Due to sensor orbit and swath width, gaps occur at the lower latitudes in daily products. We have further processed the product-streams from the descending (01:30) and ascending (13:30) orbits into separate smoothed daily composites using an 8-day retrospective moving average. Of particular interest for synoptic ecology is the diel difference in vegetation water content. When the difference between the pre-dawn and the early afternoon values is positive, it suggests that the supply of moisture from the root zone is not able to keep pace with evapotranspiration during the day, but the soil and canopy moisture equalize overnight. Time series of the diel difference show rapid changes in moisture status in response to precipitation events and dry spells. What constitutes the appropriate baseline

  15. 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

  16. 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...... for a correct taxonomic identity of this species. Copyright (c) 2008 John Wiley & Sons, Ltd....

  17. 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.

  18. Aquatic Global Passive Sampling (AQUA-GAPS) Revisited: First Steps toward a Network of Networks for Monitoring Organic Contaminants in the Aquatic Environment.

    Science.gov (United States)

    Lohmann, Rainer; Muir, Derek; Zeng, Eddy Y; Bao, Lian-Jun; Allan, Ian J; Arinaitwe, Kenneth; Booij, Kees; Helm, Paul; Kaserzon, Sarit; Mueller, Jochen F; Shibata, Yasuyuki; Smedes, Foppe; Tsapakis, Manolis; Wong, Charles S; You, Jing

    2017-02-07

    Organic contaminants, in particular persistent organic pollutants (POPs), adversely affect water quality and aquatic food webs across the globe. As of now, there is no globally consistent information available on concentrations of dissolved POPs in water bodies. The advance of passive sampling techniques has made it possible to establish a global monitoring program for these compounds in the waters of the world, which we call the Aquatic Global Passive Sampling (AQUA-GAPS) network. A recent expert meeting discussed the background, motivations, and strategic approaches of AQUA-GAPS, and its implementation as a network of networks for monitoring organic contaminants (e.g., POPs and others contaminants of concern). Initially, AQUA-GAPS will demonstrate its operating principle via two proof-of-concept studies focused on the detection of legacy and emerging POPs in freshwater and coastal marine sites using both polyethylene and silicone passive samplers. AQUA-GAPS is set up as a decentralized network, which is open to other participants from around the world to participate in deployments and to initiate new studies. In particular, participants are sought to initiate deployments and studies investigating the presence of legacy and emerging POPs in Africa, Central, and South America.

  19. 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.

  20. 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

    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...

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Estimation of Winter Wheat Biomass and Yield by Combining the AquaCrop Model and Field Hyperspectral Data

    Directory of Open Access Journals (Sweden)

    Xiuliang Jin

    2016-11-01

    Full Text Available Knowledge of spatial and temporal variations in crop growth is important for crop management and stable crop production for the food security of a country. A combination of crop growth models and remote sensing data is a useful method for monitoring crop growth status and estimating crop yield. The objective of this study was to use spectral-based biomass values generated from spectral indices to calibrate the AquaCrop model using the particle swarm optimization (PSO algorithm to improve biomass and yield estimations. Spectral reflectance and concurrent biomass and yield were measured at the Xiaotangshan experimental site in Beijing, China, during four winter wheat-growing seasons. The results showed that all of the measured spectral indices were correlated with biomass to varying degrees. The normalized difference matter index (NDMI was the best spectral index for estimating biomass, with the coefficient of determination (R2, root mean square error (RMSE, and relative RMSE (RRMSE values of 0.77, 1.80 ton/ha, and 25.75%, respectively. The data assimilation method (R2 = 0.83, RMSE = 1.65 ton/ha, and RRMSE = 23.60% achieved the most accurate biomass estimations compared with the spectral index method. The estimated yield was in good agreement with the measured yield (R2 = 0.82, RMSE = 0.55 ton/ha, and RRMSE = 8.77%. This study offers a new method for agricultural resource management through consistent assessments of winter wheat biomass and yield based on the AquaCrop model and remote sensing data.

  8. 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.

  9. 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

  10. CERES ERBE-like Instantaneous TOA Estimates (ES-8) in HDF (CER_ES8_Aqua-FM4_Edition1-CV)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The ES-8 archival data product contains a 24-hour, single-satellite, instantaneous view of scanner fluxes at the top-of-atmosphere (TOA) reduced from spacecraft altitude unfiltered radiances using Earth Radiation Budget Experiment (ERBE) scanner Inversion algorithms and the ERBE shortwave (SW) and longwave (LW) Angular Distribution Models (ADMs). The ES-8 also includes the total (TOT), SW, LW, and window (WN) channel radiometric data; SW, LW, and WN unfiltered radiance values; and the ERBE scene identification for each measurement. These data are organized according to the CERES 3.3-second scan into 6.6-second records. As long as there is one valid scanner measurement within a record, the ES-8 record will be generated. The following CERES ES8 data sets are currently available: CER_ES8_TRMM-PFM_Edition1 CER_ES8_TRMM-PFM_Edition2 CER_ES8_TRMM-PFM_Transient-Ops2 CER_ES8_Terra-FM1_Edition1 CER_ES8_Terra-FM2_Edition1 CER_ES8_Terra-FM1_Edition2 CER_ES8_Terra-FM2_Edition2 CER_ES8_Aqua-FM3_Edition1 CER_ES8_Aqua-FM4_Edition1 CER_ES8_Aqua-FM3_Edition2 CER_ES8_Aqua-FM4_Edition2 CER_ES8_Aqua-FM3_Edition1-CV CER_ES8_Aqua-FM4_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2005-03-29] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  11. CERES ERBE-like Instantaneous TOA Estimates (ES-8) in HDF (CER_ES8_Aqua-FM3_Edition1-CV)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The ES-8 archival data product contains a 24-hour, single-satellite, instantaneous view of scanner fluxes at the top-of-atmosphere (TOA) reduced from spacecraft altitude unfiltered radiances using Earth Radiation Budget Experiment (ERBE) scanner Inversion algorithms and the ERBE shortwave (SW) and longwave (LW) Angular Distribution Models (ADMs). The ES-8 also includes the total (TOT), SW, LW, and window (WN) channel radiometric data; SW, LW, and WN unfiltered radiance values; and the ERBE scene identification for each measurement. These data are organized according to the CERES 3.3-second scan into 6.6-second records. As long as there is one valid scanner measurement within a record, the ES-8 record will be generated. The following CERES ES8 data sets are currently available: CER_ES8_TRMM-PFM_Edition1 CER_ES8_TRMM-PFM_Edition2 CER_ES8_TRMM-PFM_Transient-Ops2 CER_ES8_Terra-FM1_Edition1 CER_ES8_Terra-FM2_Edition1 CER_ES8_Terra-FM1_Edition2 CER_ES8_Terra-FM2_Edition2 CER_ES8_Aqua-FM3_Edition1 CER_ES8_Aqua-FM4_Edition1 CER_ES8_Aqua-FM3_Edition2 CER_ES8_Aqua-FM4_Edition2 CER_ES8_Aqua-FM3_Edition1-CV CER_ES8_Aqua-FM4_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2006-10-31] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  12. CERES ERBE-like Instantaneous TOA Estimates (ES-8) in HDF (CER_ES8_Aqua-FM4_Edition1)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The ES-8 archival data product contains a 24-hour, single-satellite, instantaneous view of scanner fluxes at the top-of-atmosphere (TOA) reduced from spacecraft altitude unfiltered radiances using Earth Radiation Budget Experiment (ERBE) scanner Inversion algorithms and the ERBE shortwave (SW) and longwave (LW) Angular Distribution Models (ADMs). The ES-8 also includes the total (TOT), SW, LW, and window (WN) channel radiometric data; SW, LW, and WN unfiltered radiance values; and the ERBE scene identification for each measurement. These data are organized according to the CERES 3.3-second scan into 6.6-second records. As long as there is one valid scanner measurement within a record, the ES-8 record will be generated. The following CERES ES8 data sets are currently available: CER_ES8_TRMM-PFM_Edition1 CER_ES8_TRMM-PFM_Edition2 CER_ES8_TRMM-PFM_Transient-Ops2 CER_ES8_Terra-FM1_Edition1 CER_ES8_Terra-FM2_Edition1 CER_ES8_Terra-FM1_Edition2 CER_ES8_Terra-FM2_Edition2 CER_ES8_Aqua-FM3_Edition1 CER_ES8_Aqua-FM4_Edition1 CER_ES8_Aqua-FM3_Edition2 CER_ES8_Aqua-FM4_Edition2 CER_ES8_Aqua-FM3_Edition1-CV CER_ES8_Aqua-FM4_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2005-03-29] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  13. CERES ERBE-like Instantaneous TOA Estimates (ES-8) in HDF (CER_ES8_Aqua-FM4_Edition2)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The ES-8 archival data product contains a 24-hour, single-satellite, instantaneous view of scanner fluxes at the top-of-atmosphere (TOA) reduced from spacecraft altitude unfiltered radiances using Earth Radiation Budget Experiment (ERBE) scanner Inversion algorithms and the ERBE shortwave (SW) and longwave (LW) Angular Distribution Models (ADMs). The ES-8 also includes the total (TOT), SW, LW, and window (WN) channel radiometric data; SW, LW, and WN unfiltered radiance values; and the ERBE scene identification for each measurement. These data are organized according to the CERES 3.3-second scan into 6.6-second records. As long as there is one valid scanner measurement within a record, the ES-8 record will be generated. The following CERES ES8 data sets are currently available: CER_ES8_TRMM-PFM_Edition1 CER_ES8_TRMM-PFM_Edition2 CER_ES8_TRMM-PFM_Transient-Ops2 CER_ES8_Terra-FM1_Edition1 CER_ES8_Terra-FM2_Edition1 CER_ES8_Terra-FM1_Edition2 CER_ES8_Terra-FM2_Edition2 CER_ES8_Aqua-FM3_Edition1 CER_ES8_Aqua-FM4_Edition1 CER_ES8_Aqua-FM3_Edition2 CER_ES8_Aqua-FM4_Edition2 CER_ES8_Aqua-FM3_Edition1-CV CER_ES8_Aqua-FM4_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2005-03-29] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  14. CERES ERBE-like Instantaneous TOA Estimates (ES-8) in HDF (CER_ES8_Aqua-FM3_Edition2)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The ES-8 archival data product contains a 24-hour, single-satellite, instantaneous view of scanner fluxes at the top-of-atmosphere (TOA) reduced from spacecraft altitude unfiltered radiances using Earth Radiation Budget Experiment (ERBE) scanner Inversion algorithms and the ERBE shortwave (SW) and longwave (LW) Angular Distribution Models (ADMs). The ES-8 also includes the total (TOT), SW, LW, and window (WN) channel radiometric data; SW, LW, and WN unfiltered radiance values; and the ERBE scene identification for each measurement. These data are organized according to the CERES 3.3-second scan into 6.6-second records. As long as there is one valid scanner measurement within a record, the ES-8 record will be generated. The following CERES ES8 data sets are currently available: CER_ES8_TRMM-PFM_Edition1 CER_ES8_TRMM-PFM_Edition2 CER_ES8_TRMM-PFM_Transient-Ops2 CER_ES8_Terra-FM1_Edition1 CER_ES8_Terra-FM2_Edition1 CER_ES8_Terra-FM1_Edition2 CER_ES8_Terra-FM2_Edition2 CER_ES8_Aqua-FM3_Edition1 CER_ES8_Aqua-FM4_Edition1 CER_ES8_Aqua-FM3_Edition2 CER_ES8_Aqua-FM4_Edition2 CER_ES8_Aqua-FM3_Edition1-CV CER_ES8_Aqua-FM4_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV CER_ES8_Terra-FM1_Edition1-CV. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=2005-12-31] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180] [Data_Resolution: Temporal_Resolution=1 day; Temporal_Resolution_Range=Daily - < Weekly].

  15. 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

  16. 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.

  17. 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

  18. Deposition, persistence and turnover of pollutants: first results from the EU project AquaTerra for selected river basins and aquifers

    DEFF Research Database (Denmark)

    Barth, J.A.C.; Steidle, D.; Kuntz, D.

    2007-01-01

    Deposition, turnover and movement of persistent organic pollutants (POP) were investigated in the EU integrated project "AquaTerra", which is among the first funded environmental projects within the 6th Framework Program by the European Commission. Project work integrates across various disciplines...... of the project more than 1700 samples of atmospherically deposited particles, sediments, and water have been collected in the above-mentioned systems. Results show clear spatial patterns of deposition of polyaromatic hydrocarbons (PAHs) with the highest rates in the Meuse Basin. For local inputs......, Germany). These selected preliminary results of AquaTerra help to improve fundamental understanding of persistent organic pollutants (POP) in the environment. (c) 2007 Elsevier B.V. All rights reserved....

  19. 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.

  20. 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

  1. 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.

  2. Assessment of growth rate, chlorophyll a fluorescence, lipid peroxidation and antioxidant enzyme activity in Aphanizomenon flos-aquae, Pediastrum simplex and Synedra acus exposed to cadmium.

    Science.gov (United States)

    Ran, Xiaofei; Liu, Rui; Xu, Sha; Bai, Fang; Xu, Jinzhu; Yang, Yanjun; Shi, Junqiong; Wu, Zhongxing

    2015-03-01

    In this study, the effects of cadmium on the cyanobacterium Aphanizomenon flos-aquae, the green alga Pediastrum simplex and the diatom Synedra acus was evaluated on the basis of growth rate, chlorophyll a fluorescence, lipid peroxidation and antioxidant enzyme activity. The EC50 values (effective concentration inducing 50 % of growth inhibition) of cadmium in A. flos-aquae, P. simplex and S. acus were 1.18 ± 0.044, 4.32 ± 0.068 and 3.7 ± 0.055 mg/L, respectively. The results suggested that cadmium stress decreases growth rate and chlorophyll a concentration. The normalized chlorophyll a fluorescence transients significantly increased at cadmium concentrations of 5.0, 10.0 and 20.0 mg/L, but slightly decreased at concentrations of 0.2, 0.5 and 1.0 mg/L. The chlorophyll fluorescence parameters showed considerable variation among the three species, while lipid peroxidation and antioxidant enzyme activities showed a significant increase. Our results demonstrated that blockage of electron transport on the acceptor side of photosystem II is the mechanism responsible for cadmium toxicity in freshwater microalgae, and that the tolerance of the three species to cadmium was in the order green alga P. simplex > diatom S. acus > cyanobacterium A. flos-aquae.

  3. 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.

  4. Farmland Drought Evaluation Based on the Assimilation of Multi-Temporal Multi-Source Remote Sensing Data into AquaCrop Model

    Science.gov (United States)

    Yang, Guijun; Yang, Hao; Jin, Xiuliang; Pignatti, Stefano; Casa, Faffaele; Silverstro, Paolo Cosmo

    2016-08-01

    Drought is the most costly natural disasters in China and all over the world. It is very important to evaluate the drought-induced crop yield losses and further improve water use efficiency at regional scale. Firstly, crop biomass was estimated by the combined use of Synthetic Aperture Radar (SAR) and optical remote sensing data. Then the estimated biophysical variable was assimilated into crop growth model (FAO AquaCrop) by the Particle Swarm Optimization (PSO) method from farmland scale to regional scale.At farmland scale, the most important crop parameters of AquaCrop model were determined to reduce the used parameters in assimilation procedure. The Extended Fourier Amplitude Sensitivity Test (EFAST) method was used for assessing the contribution of different crop parameters to model output. Moreover, the AquaCrop model was calibrated using the experiment data in Xiaotangshan, Beijing.At regional scale, spatial application of our methods were carried out and validated in the rural area of Yangling, Shaanxi Province, in 2014. This study will provide guideline to make irrigation decision of balancing of water consumption and yield loss.

  5. 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.

  6. 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...

  7. Nutritional and anti-nutritional composition of cassava leaf protein concentrate from six cassava varieties for use in aqua feed

    Directory of Open Access Journals (Sweden)

    A. Oresegun

    2016-12-01

    Full Text Available Leaves from six varieties of cassava (Manihot esculenta crantz cultivated in Nigeria were harvested and analysed for their nutritional composition and anti-nutritional factors using standard analytical techniques. The leaves were further processed into cassava leaf protein concentrate. Results obtained indicated highest crude protein levels, β-carotene levels and lipid levels of 48.85 ± 0.45, 816.92 ± 8.80 and 13.27 ± 0.06, respectively, in variety 419 and lowest crude protein levels and β-carotene levels of 40.19 ± 0.08 and 298 ± 5.74 in variety 326. However, ash, moisture and carbohydrate levels for all six varieties were relatively the same. Mineral compositions for all varieties were also fairly similar. Hydrogen cyanide levels were significantly low (p > 0.05 in variety 419 with a value of 0.98 ± 0.05. However, phytate and tannin levels for all six varieties were not significantly different (p > 0.05. It can be concluded from this study that cassava variety 419 had the highest potential for use in aqua feed production.

  8. Moisture flux changes and trends for the entire Arctic in 2003-2011 derived from EOS Aqua data

    Science.gov (United States)

    Boisvert, L. N.; Markus, T.; Vihma, T. P.

    2013-12-01

    The Arctic sea ice acts as a barrier between the ocean and lower atmosphere, reducing the exchange of heat and moisture. In recent years the ice pack has undergone many changes, in particular a rapid reduction in sea ice extent and compactness in summer and autumn. This, along with modeling studies, would cause one to believe that the moisture flux would be increasing. We estimate the daily moisture flux from 2003-2011 using geophysical data from multiple sensors onboard NASA's Aqua satellite, taking advantage of observations being collected at the same time and along the same track. Our findings show the moisture flux, averaged over the entire Arctic, has had large interannual variations. Increases in air specific humidity tend to reduce the moisture flux, whereas the decrease in sea ice cover tends to increase the flux. Statistically significant seasonal decreasing trends are seen in December, January and February because of the dominating effect of increase in 2m air specific humidity increasing, reducing the surface-air specific humidity difference by -0.0547 kg/kg in the Kara/Barents Seas, E. Greenland Sea and Baffin Bay regions where there is some open water year round. Our results also show that the contribution of the sea ice zone to the total moisture flux has increased by 3.6% because the amount of open water within the sea ice has increased by 4.3%.

  9. Effects of Cu(II) complexes on photosynthesis in spinach chloroplasts. Aqua(aryloxyacetato)copper(II) complexes.

    Science.gov (United States)

    Král'ová, K; Sersen, F; Blahová, M

    1994-12-01

    The inhibitory effect of 14 aqua(aryloxyacetato) copper(II) complexes on oxygen evolution rate in spinach chloroplasts has been investigated. The inhibitory effect of these effectors on photosynthesis was confirmed by Hill reaction as well as by EPR and fluorescence spectroscopies. The results of the EPR study showed that the sites of action of the studied effectors are Z+ and Y+ intermediates at the donor side of the photosystem (PS) 2. The EPR study also showed that another site of action is the oxygen evolving complex, namely its manganese cluster. The above suggestions were supported by the results of the fluorescence study as well. Based on the restoring of the photosynthetic electron transport to 2,6-dichlorophenol-indophenol in chloroplasts inhibited by the studied Cu(II) complexes using sym-diphenylcarbazide it can be assumed that the own core of PS2 (P680) and a part of the electron transport chain-at least up to plastoquinone-remain intact.

  10. 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.

  11. 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

  12. About uncertainties in sea ice thickness retrieval from satellite radar altimetry: results from the ESA-CCI Sea Ice ECV Project Round Robin Exercise

    Science.gov (United States)

    Kern, S.; Khvorostovsky, K.; Skourup, H.; Rinne, E.; Parsakhoo, Z. S.; Djepa, V.; Wadhams, P.; Sandven, S.

    2014-03-01

    One goal of the European Space Agency Climate Change Initiative sea ice Essential Climate Variable project is to provide a quality controlled 20 year long data set of Arctic Ocean winter-time sea ice thickness distribution. An important step to achieve this goal is to assess the accuracy of sea ice thickness retrieval based on satellite radar altimetry. For this purpose a data base is created comprising sea ice freeboard derived from satellite radar altimetry between 1993 and 2012 and collocated observations of snow and sea ice freeboard from Operation Ice Bridge (OIB) and CryoSat Validation Experiment (CryoVEx) air-borne campaigns, of sea ice draft from moored and submarine Upward Looking Sonar (ULS), and of snow depth from OIB campaigns, Advanced Microwave Scanning Radiometer aboard EOS (AMSR-E) and the Warren Climatology (Warren et al., 1999). An inter-comparison of the snow depth data sets stresses the limited usefulness of Warren climatology snow depth for freeboard-to-thickness conversion under current Arctic Ocean conditions reported in other studies. This is confirmed by a comparison of snow freeboard measured during OIB and CryoVEx and snow freeboard computed from radar altimetry. For first-year ice the agreement between OIB and AMSR-E snow depth within 0.02 m suggests AMSR-E snow depth as an appropriate alternative. Different freeboard-to-thickness and freeboard-to-draft conversion approaches are realized. The mean observed ULS sea ice draft agrees with the mean sea ice draft computed from radar altimetry within the uncertainty bounds of the data sets involved. However, none of the realized approaches is able to reproduce the seasonal cycle in sea ice draft observed by moored ULS satisfactorily. A sensitivity analysis of the freeboard-to-thickness conversion suggests: in order to obtain sea ice thickness as accurate as 0.5 m from radar altimetry, besides a freeboard estimate with centimetre accuracy, an ice-type dependent sea ice density is as mandatory

  13. Developing a dual assimilation approach for thermal infrared and passive microwave soil moisture retrievals

    Science.gov (United States)

    Hain, Christopher Ryan

    Soil moisture plays a vital role in the partitioning of sensible and latent heat fluxes in the surface energy budget and the lack of a dense spatial and temporal network of ground-based observations provides a challenge to the initialization of the true soil moisture state in numerical weather prediction simulations. The retrieval of soil moisture using observations from both satellite-based thermal-infrared (TIR) and passive microwave (PM) sensors has been developed (Anderson et al., 2007; Hain et al., 2009; Jackson, 1993; Njoku et al., 2003). The ability of the TIR and microwave observations to diagnose soil moisture conditions within different layers of the soil profile provides an opportunity to use each in a synergistic data assimilation approach towards the goal of diagnosing the true soil moisture state from surface to root-zone. TIR and PM retrievals of soil moisture are compared to soil moisture estimates provided by a retrospective Land Information System (LIS) simulation using the NOAH LSM during the time period of 2003--2008. The TIR-based soil moisture product is provided by a retrieval of soil moisture associated with surface flux estimates from the Atmosphere-Land-Exchange-Inversion (ALEXI) model (Anderson et al., 1997; Mecikalski et al., 1999; Hain et al., 2009). The PM soil moisture retrieval is provided by the Vrijie Universiteit Amsterdam (VUA)-NASA surface soil moisture product. The VUA retrieval is based on the findings of Owe et al. (2001; 2008) using the Land Surface Parameter model (LPRM), which uses one dual polarized channel (6.925 or 10.65 GHz) for a dual-retrieval of surface soil moisture and vegetation water content. In addition, retrievals of ALEXI (TIR) and AMSR-E (PM) soil moisture are assimilated within the Land Information System using the NOAH LSM. A series of data assimilation experiments is completed with the following configuration: (a) no assimilation, (b) only ALEXI soil moisture, (c) only AMSR-E soil moisture, and (d) ALEXI

  14. 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。

  15. 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

  16. 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.

  17. The response and detoxification strategies of three freshwater phytoplankton species, Aphanizomenon flos-aquae, Pediastrum simplex, and Synedra acus, to cadmium.

    Science.gov (United States)

    Ran, Xiaofei; Yue, Hong; Fu, Xiaoli; Kang, Yuanhao; Xu, Sha; Yang, Yanjun; Xu, Jinzhu; Shi, Junqiong; Wu, Zhongxing

    2015-12-01

    The response and detoxification mechanisms of three freshwater phytoplankton species (the cyanobacterium Aphanizomenon flos-aquae, the green alga Pediastrum simplex, and the diatom Synedra acus) to cadmium (Cd) were investigated. The cell growth of each species was measured over 10 days, and chlorophyll a fluorescence, Cd bioaccumulation (including surface-adsorbed and intracellular Cd), and phytochelatin (PC) synthesis were determined after 96-h exposures. The growth of the three phytoplankton species was significantly inhibited when Cd concentrations were ≥5 mg L(-1). Compared with P. simplex, greater growth inhibition in S. acus and A. flos-aquae occurred. The changes in chlorophyll fluorescence parameters including the maximal quantum yield of PSII (Fv/Fm) and relative variable fluorescence of the J point (Vj) demonstrated that the increase in Cd concentration damaged PSII in all three species. After 96-h exposures, the accumulation of surface-adsorbed Cd and intracellular Cd increased significantly in all three species, with the increase of Cd concentrations in the media; total cadmium accumulation was 245, 658, and 1670 times greater than that of the control in A. flos-aquae, P. simplex, and S. acus, respectively, after exposure to 10 mg L(-1). Total thiols exhibited a similar trend to that of Cd accumulation. PC3 was found in A. flos-aquae and P. simplex in all Cd treatments. Glutathione (GSH) and PC2 were also produced in response to exposure to high concentrations of Cd. PC4 was only discovered at exposure concentrations of 10 mg L(-1) Cd and only in S. acus. The intracellular Cd/PCs ratio increased in all three phytoplankton with an increase in Cd concentrations, and a linear relationship between the ratio and the growth inhibition rates was observed with P. simplex and S. acus. Our results have demonstrated that metal detoxification mechanisms were dependent on the species. This study suggested that the variance of metal detoxification strategies, such

  18. Chiral Pd aqua complex-catalyzed asymmetric C-C bond-forming reactions: a Brønsted acid-base cooperative system.

    Science.gov (United States)

    Sodeoka, Mikiko; Hamashima, Yoshitaka

    2009-10-21

    Chiral cationic Pd aqua complexes can function as acid-base catalysts, effectively activating active methylene and methine compounds to give chiral Pd enolates. It is noteworthy that such enolate formation occurs with concomitant formation of a strong protic acid. Although the reactivity of the Pd enolate itself is not sufficient for reactions with carbon-based electrophiles, its cooperative action with the protic acid to activate the electrophiles allows the desired C-C bond-forming reactions to proceed smoothly in a highly enantioselective manner. Based on this mechanistic feature, reactions with acetals have been developed; these are difficult to achieve using conventional basic enolate chemistry.

  19. 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.

  20. CERES Single Satellite Footprint, TOA and Surface Fluxes, Clouds (SSF) data in HDF (CER_SSF_Aqua-FM3-MODIS_Edition2A)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The Single Scanner Footprint TOA/Surface Fluxes and Clouds (SSF) product contains one hour of instantaneous Clouds and the Earth's Radiant Energy System (CERES) data for a single scanner instrument. The SSF combines instantaneous CERES data with scene information from a higher-resolution imager such as Visible/Infrared Scanner (VIRS) on TRMM or Moderate-Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua. Scene identification and cloud properties are defined at the higher imager resolution and these data are averaged over the larger CERES footprint. For each CERES footprint, the SSF contains the number of cloud layers and for each layer the cloud amount, height, temperature, pressure, optical depth, emissivity, ice and liquid water path, and water particle size. The SSF also contains the CERES filtered radiances for the total, shortwave (SW), and window (WN) channels and the unfiltered SW, longwave (LW), and WN radiances. The SW, LW, and WN radiances at spacecraft altitude are converted to Top-of-the-Atmosphere (TOA) fluxes based on the imager defined scene. These TOA fluxes are used to estimate surface fluxes. Only footprints with adequate imager coverage are included on CER_SSF_TRMM-PFM-VIRS_Subset_Edition1the SSF which is much less than the full set of footprints on the CERES ES-8 product. The following CERES SSF data sets are currently available: CER_SSF_TRMM-PFM-VIRS_Edition1 CER_SSF_TRMM-PFM-VIRS_Subset_Edition1 CER_SSF_TRMM-PFM-VIRS_Edition2A CER_SSF_TRMM-SIM-VIRS_Edition2_VIRSonly CER_SSF_TRMM-PFM-VIRS_Edition2A-TransOps CER_SSF_TRMM-PFM-VIRS_Edition2B-TransOps CER_SSF_TRMM-PFM-VIRS_Edition2B CER_SSF_Terra-FM1-MODIS_Edition1A CER_SSF_Terra-FM1-MODIS_Edition1A CER_SSF_Terra-FM1-MODIS_Edition2A CER_SSF_Terra-FM2-MODIS_Edition2A CER_SSF_Terra-FM1-MODIS_Edition2B CER_SSF_Terra-FM2-MODIS_Edition2B CER_SSF_Aqua-FM4-MODIS_Beta1 CER_SSF_Aqua-FM3-MODIS_Beta2 CER_SSF_Aqua-FM4-MODIS_Beta2. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1998-01-01; Stop

  1. CERES Single Scanner Satellite Footprint, TOA, Surface Fluxes and Clouds (SSF) data in HDF (CER_SSF_Aqua-FM3-MODIS_Edition1B)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The Single Scanner Footprint TOA/Surface Fluxes and Clouds (SSF) product contains one hour of instantaneous Clouds and the Earth's Radiant Energy System (CERES) data for a single scanner instrument. The SSF combines instantaneous CERES data with scene information from a higher-resolution imager such as Visible/Infrared Scanner (VIRS) on TRMM or Moderate-Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua. Scene identification and cloud properties are defined at the higher imager resolution and these data are averaged over the larger CERES footprint. For each CERES footprint, the SSF contains the number of cloud layers and for each layer the cloud amount, height, temperature, pressure, optical depth, emissivity, ice and liquid water path, and water particle size. The SSF also contains the CERES filtered radiances for the total, shortwave (SW), and window (WN) channels and the unfiltered SW, longwave (LW), and WN radiances. The SW, LW, and WN radiances at spacecraft altitude are converted to Top-of-the-Atmosphere (TOA) fluxes based on the imager defined scene. These TOA fluxes are used to estimate surface fluxes. Only footprints with adequate imager coverage are included on CER_SSF_TRMM-PFM-VIRS_Subset_Edition1the SSF which is much less than the full set of footprints on the CERES ES-8 product. The following CERES SSF data sets are currently available: CER_SSF_TRMM-PFM-VIRS_Edition1 CER_SSF_TRMM-PFM-VIRS_Subset_Edition1 CER_SSF_TRMM-PFM-VIRS_Edition2A CER_SSF_TRMM-SIM-VIRS_Edition2_VIRSonly CER_SSF_TRMM-PFM-VIRS_Edition2A-TransOps CER_SSF_TRMM-PFM-VIRS_Edition2B-TransOps CER_SSF_TRMM-PFM-VIRS_Edition2B CER_SSF_Terra-FM1-MODIS_Edition1A CER_SSF_Terra-FM1-MODIS_Edition1A CER_SSF_Terra-FM1-MODIS_Edition2A CER_SSF_Terra-FM2-MODIS_Edition2A CER_SSF_Terra-FM1-MODIS_Edition2B CER_SSF_Terra-FM2-MODIS_Edition2B CER_SSF_Aqua-FM4-MODIS_Beta1 CER_SSF_Aqua-FM3-MODIS_Beta2 CER_SSF_Aqua-FM4-MODIS_Beta2. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1998-01-01; Stop

  2. CERES Single Scanner Satellite Footprint, TOA, Surface Fluxes and Clouds (SSF) data in HDF (CER_SSF_Aqua-FM4-MODIS_Edition1B)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The Single Scanner Footprint TOA/Surface Fluxes and Clouds (SSF) product contains one hour of instantaneous Clouds and the Earth's Radiant Energy System (CERES) data for a single scanner instrument. The SSF combines instantaneous CERES data with scene information from a higher-resolution imager such as Visible/Infrared Scanner (VIRS) on TRMM or Moderate-Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua. Scene identification and cloud properties are defined at the higher imager resolution and these data are averaged over the larger CERES footprint. For each CERES footprint, the SSF contains the number of cloud layers and for each layer the cloud amount, height, temperature, pressure, optical depth, emissivity, ice and liquid water path, and water particle size. The SSF also contains the CERES filtered radiances for the total, shortwave (SW), and window (WN) channels and the unfiltered SW, longwave (LW), and WN radiances. The SW, LW, and WN radiances at spacecraft altitude are converted to Top-of-the-Atmosphere (TOA) fluxes based on the imager defined scene. These TOA fluxes are used to estimate surface fluxes. Only footprints with adequate imager coverage are included on CER_SSF_TRMM-PFM-VIRS_Subset_Edition1the SSF which is much less than the full set of footprints on the CERES ES-8 product. The following CERES SSF data sets are currently available: CER_SSF_TRMM-PFM-VIRS_Edition1 CER_SSF_TRMM-PFM-VIRS_Subset_Edition1 CER_SSF_TRMM-PFM-VIRS_Edition2A CER_SSF_TRMM-SIM-VIRS_Edition2_VIRSonly CER_SSF_TRMM-PFM-VIRS_Edition2A-TransOps CER_SSF_TRMM-PFM-VIRS_Edition2B-TransOps CER_SSF_TRMM-PFM-VIRS_Edition2B CER_SSF_Terra-FM1-MODIS_Edition1A CER_SSF_Terra-FM1-MODIS_Edition1A CER_SSF_Terra-FM1-MODIS_Edition2A CER_SSF_Terra-FM2-MODIS_Edition2A CER_SSF_Terra-FM1-MODIS_Edition2B CER_SSF_Terra-FM2-MODIS_Edition2B CER_SSF_Aqua-FM4-MODIS_Beta1 CER_SSF_Aqua-FM3-MODIS_Beta2 CER_SSF_Aqua-FM4-MODIS_Beta2. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1998-01-01; Stop

  3. CERES Single Satellite Footprint, TOA and Surface Fluxes, Clouds (SSF) data in HDF (CER_SSF_Aqua-FM4-MODIS_Edition2A)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The Single Scanner Footprint TOA/Surface Fluxes and Clouds (SSF) product contains one hour of instantaneous Clouds and the Earth's Radiant Energy System (CERES) data for a single scanner instrument. The SSF combines instantaneous CERES data with scene information from a higher-resolution imager such as Visible/Infrared Scanner (VIRS) on TRMM or Moderate-Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua. Scene identification and cloud properties are defined at the higher imager resolution and these data are averaged over the larger CERES footprint. For each CERES footprint, the SSF contains the number of cloud layers and for each layer the cloud amount, height, temperature, pressure, optical depth, emissivity, ice and liquid water path, and water particle size. The SSF also contains the CERES filtered radiances for the total, shortwave (SW), and window (WN) channels and the unfiltered SW, longwave (LW), and WN radiances. The SW, LW, and WN radiances at spacecraft altitude are converted to Top-of-the-Atmosphere (TOA) fluxes based on the imager defined scene. These TOA fluxes are used to estimate surface fluxes. Only footprints with adequate imager coverage are included on CER_SSF_TRMM-PFM-VIRS_Subset_Edition1the SSF which is much less than the full set of footprints on the CERES ES-8 product. The following CERES SSF data sets are currently available: CER_SSF_TRMM-PFM-VIRS_Edition1 CER_SSF_TRMM-PFM-VIRS_Subset_Edition1 CER_SSF_TRMM-PFM-VIRS_Edition2A CER_SSF_TRMM-SIM-VIRS_Edition2_VIRSonly CER_SSF_TRMM-PFM-VIRS_Edition2A-TransOps CER_SSF_TRMM-PFM-VIRS_Edition2B-TransOps CER_SSF_TRMM-PFM-VIRS_Edition2B CER_SSF_Terra-FM1-MODIS_Edition1A CER_SSF_Terra-FM1-MODIS_Edition1A CER_SSF_Terra-FM1-MODIS_Edition2A CER_SSF_Terra-FM2-MODIS_Edition2A CER_SSF_Terra-FM1-MODIS_Edition2B CER_SSF_Terra-FM2-MODIS_Edition2B CER_SSF_Aqua-FM4-MODIS_Beta1 CER_SSF_Aqua-FM3-MODIS_Beta2 CER_SSF_Aqua-FM4-MODIS_Beta2. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1998-01-01; Stop

  4. CERES Single Satellite Footprint, TOA and Surface Fluxes, Clouds (SSF) data in HDF (CER_SSF_Aqua-FM4-MODIS_Ed2A-NoSW)

    Science.gov (United States)

    Wielicki, Bruce A. (Principal Investigator)

    The Single Scanner Footprint TOA/Surface Fluxes and Clouds (SSF) product contains one hour of instantaneous Clouds and the Earth's Radiant Energy System (CERES) data for a single scanner instrument. The SSF combines instantaneous CERES data with scene information from a higher-resolution imager such as Visible/Infrared Scanner (VIRS) on TRMM or Moderate-Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua. Scene identification and cloud properties are defined at the higher imager resolution and these data are averaged over the larger CERES footprint. For each CERES footprint, the SSF contains the number of cloud layers and for each layer the cloud amount, height, temperature, pressure, optical depth, emissivity, ice and liquid water path, and water particle size. The SSF also contains the CERES filtered radiances for the total, shortwave (SW), and window (WN) channels and the unfiltered SW, longwave (LW), and WN radiances. The SW, LW, and WN radiances at spacecraft altitude are converted to Top-of-the-Atmosphere (TOA) fluxes based on the imager defined scene. These TOA fluxes are used to estimate surface fluxes. Only footprints with adequate imager coverage are included on CER_SSF_TRMM-PFM-VIRS_Subset_Edition1the SSF which is much less than the full set of footprints on the CERES ES-8 product. The following CERES SSF data sets are currently available: CER_SSF_TRMM-PFM-VIRS_Edition1 CER_SSF_TRMM-PFM-VIRS_Subset_Edition1 CER_SSF_TRMM-PFM-VIRS_Edition2A CER_SSF_TRMM-SIM-VIRS_Edition2_VIRSonly CER_SSF_TRMM-PFM-VIRS_Edition2A-TransOps CER_SSF_TRMM-PFM-VIRS_Edition2B-TransOps CER_SSF_TRMM-PFM-VIRS_Edition2B CER_SSF_Terra-FM1-MODIS_Edition1A CER_SSF_Terra-FM1-MODIS_Edition1A CER_SSF_Terra-FM1-MODIS_Edition2A CER_SSF_Terra-FM2-MODIS_Edition2A CER_SSF_Terra-FM1-MODIS_Edition2B CER_SSF_Terra-FM2-MODIS_Edition2B CER_SSF_Aqua-FM4-MODIS_Beta1 CER_SSF_Aqua-FM3-MODIS_Beta2 CER_SSF_Aqua-FM4-MODIS_Beta2. [Location=GLOBAL] [Temporal_Coverage: Start_Date=1998-01-01; Stop

  5. 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.

  6. 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.

  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

    2011-03-01

    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.

  8. 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

  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. 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.

  11. Initial evaluation and assimilation of FY-3A atmospheric sounding data in the ECMWF System

    Institute of Scientific and Technical Information of China (English)

    LU QiFeng

    2011-01-01

    Fengyuan 3A (FY-3A) was the first Chinese second-generation meteorological satellite.Most of the onboard sensors were used for the first time.Four of the eleven sensors [1] accumulated data for numerical weather forecasting:the Microwave Radiation Imager (MWRI,similar to the AMSR-E) and three vertical atmospheric sensors.The vertical sensors were the Microwave Temperature Sensor (MWTS,similar to the MSU or AMSU-A),the Microwave Humidity Sounder (MWHS,similar to the AMSU-B or MHS),and the Infrared Atmospheric Sounder (IRAS,similar to the HIRS).It is necessary to objectively examine and evaluate the operational performance of the four FY-3A sensors,the quality of the data they provide,and their application potential in numerical weather forecasting to develop future FY-3 sensors and prompt the assimilation of FY-3 data in weather forecasting.

  12. 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.

  13. 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%.

  14. 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

  15. 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.

  16. 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.

  17. Poly[hexa-aqua-(μ9-cyclo-hexane-1,2,3,4,5,6-hexa-carboxyl-ato)trimanganese(II)].

    Science.gov (United States)

    Sun, Weixuan; Zang, Hu; Quan, Chengshi

    2013-01-01

    The asymmetric unit of the title compound, [Mn3(C12H6O12)(H2O)6] n , comprises one Mn(II) ion, one third of a cyclo-hexane-1,2,3,4,5,6-hexa-carboxyl-ate anion and two aqua ligands. The anion is completed by application of a -3 axis. The Mn(II) ion is six-coordinated by six O atoms from two aqua ligands and three different cyclo-hexa-carboxyl-ate anions in an octa-hedral geometry. The six carboxyl-ate groups adopt a bridging bidentate mode to ligate the Mn(II) ions. Thus, each cyclo-hexane-1,2,3,4,5,6-hexa-carboxyl-ate anion adopts a μ9-connected mode, ligating nine different Mn(II) ions and forming a three-dimensional framework. In the framework, there are strong O-H⋯O hydrogen-bonding inter-actions, which further stabilize the crystal structure.

  18. Determination of Se in biological samples by axial view inductively coupled plasma optical emission spectrometry after digestion with aqua regia and on-line chemical vapor generation

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Eder Jose dos [Instituto de Tecnologia do Parana (TECPAR), 81350-010 Curitiba, PR (Brazil)], E-mail: eder@tecpar.br; Herrmann, Amanda Beatriz; Kulik de Caires, Suzete [Instituto de Tecnologia do Parana (TECPAR), 81350-010 Curitiba, PR (Brazil); Azzolin Frescura, Vera Lucia; Curtius, Adilson Jose [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), 880400-900 Florianopolis, SC (Brazil)

    2009-06-15

    A simple and fast method for the determination of Se in biological samples, including food, by axial view inductively coupled plasma optical emission spectrometry using on-line chemical vapor generation (CVG-ICP OES) is proposed. The concentrations of HCl and NaBH{sub 4}, used in the chemical vapor generation were optimized by factorial analysis. Six certified materials (non-fat milk powder, lobster hepatopancreas, human hair, whole egg powder, oyster tissue, and lyophilised pig kidney) were treated with 10 mL of aqua regia in a microwave system under reflux for 15 min followed by additional 15 min in an ultrasonic bath. The solutions were transferred to a 100 mL volumetric flask and the final volume was made up with water. The Se was determined directly in these solutions by CVG-ICP OES, using the analytical line at 196.026 nm. Calibration against aqueous standards in 10% v/v aqua regia in the concentration range of 0.5-10.0 {mu}g L{sup -} {sup 1} Se(IV) was used for the analysis. The quantification limit, considering a 0.5 g sample weight in a final volume of 100 mL{sup -} {sup 1} was 0.10 {mu}g g{sup -} {sup 1}. The obtained concentration values were in agreement with the total certified concentrations, according to the t-test for a 95% confidence level.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. Satellite microwave assessment of Northern Hemisphere lake ice phenology from 2002 to 2015

    Science.gov (United States)

    Du, Jinyang; Kimball, John S.; Duguay, Claude; Kim, Youngwook; Watts, Jennifer D.

    2017-01-01

    A new automated method enabling consistent satellite assessment of seasonal lake ice phenology at 5 km resolution was developed for all lake pixels (water coverage ≥ 90 %) in the Northern Hemisphere using 36.5 GHz H-polarized brightness temperature (Tb) observations from the Advanced Microwave Scanning Radiometer for EOS and Advanced Microwave Scanning Radiometer 2 (AMSR-E/2) sensors. The lake phenology metrics include seasonal timing and duration of annual ice cover. A moving t test (MTT) algorithm allows for automated lake ice retrievals with daily temporal fidelity and 5 km resolution gridding. The resulting ice phenology record shows strong agreement with available ground-based observations from the Global Lake and River Ice Phenology Database (95.4 % temporal agreement) and favorable correlations (R) with alternative ice phenology records from the Interactive Multisensor Snow and Ice Mapping System (R = 0.84 for water clear of ice (WCI) dates; R = 0.41 for complete freeze over (CFO) dates) and Canadian Ice Service (R = 0.86 for WCI dates; R = 0.69 for CFO dates). Analysis of the resulting 12-year (2002-2015) AMSR-E/2 ice record indicates increasingly shorter ice cover duration for 43 out of 71 (60.6 %) Northern Hemisphere lakes examined, with significant (p regional trends toward earlier ice melting for only five lakes. Higher-latitude lakes reveal more widespread and larger trends toward shorter ice cover duration than lower-latitude lakes, consistent with enhanced polar warming. This study documents a new satellite-based approach for rapid assessment and regional monitoring of seasonal ice cover changes over large lakes, with resulting accuracy suitable for global change studies.

  5. 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.

  6. Towards Improved Snow Water Equivalent Estimation via GRACE Assimilation

    Science.gov (United States)

    Forman, Bart; Reichle, Rofl; Rodell, Matt

    2011-01-01

    Passive microwave (e.g. AMSR-E) and visible spectrum (e.g. MODIS) measurements of snow states have been used in conjunction with land surface models to better characterize snow pack states, most notably snow water equivalent (SWE). However, both types of measurements have limitations. AMSR-E, for example, suffers a loss of information in deep/wet snow packs. Similarly, MODIS suffers a loss of temporal correlation information beyond the initial accumulation and final ablation phases of the snow season. Gravimetric measurements, on the other hand, do not suffer from these limitations. In this study, gravimetric measurements from the Gravity Recovery and Climate Experiment (GRACE) mission are used in a land surface model data assimilation (DA) framework to better characterize SWE in the Mackenzie River basin located in northern Canada. Comparisons are made against independent, ground-based SWE observations, state-of-the-art modeled SWE estimates, and independent, ground-based river discharge observations. Preliminary results suggest improved SWE estimates, including improved timing of the subsequent ablation and runoff of the snow pack. Additionally, use of the DA procedure can add vertical and horizontal resolution to the coarse-scale GRACE measurements as well as effectively downscale the measurements in time. Such findings offer the potential for better understanding of the hydrologic cycle in snow-dominated basins located in remote regions of the globe where ground-based observation collection if difficult, if not impossible. This information could ultimately lead to improved freshwater resource management in communities dependent on snow melt as well as a reduction in the uncertainty of river discharge into the Arctic Ocean.

  7. 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.

  8. 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.

  9. Impact of SMOS soil moisture data assimilation on NCEP-GFS forecasts

    Science.gov (United States)

    Zhan, X.; Zheng, W.; Meng, J.; Dong, J.; Ek, M.

    2012-04-01

    Soil moisture is one of the few critical land surface state variables that have long memory to impact the exchanges of water, energy and carbon between the land surface and atmosphere. Accurate information about soil moisture status is thus required for numerical weather, seasonal climate and hydrological forecast as well as for agricultural production forecasts, water management and many other water related economic or social activities. Since the successful launch of ESA's soil moisture ocean salinity (SMOS) mission in November 2009, about 2 years of soil moisture retrievals has been collected. SMOS is believed to be the currently best satellite sensors for soil moisture remote sensing. Therefore, it becomes interesting to examine how the collected SMOS soil moisture data are compared with other satellite-sensed soil moisture retrievals (such as NASA's Advanced Microwave Scanning Radiometer -AMSR-E and EUMETSAT's Advanced Scatterometer - ASCAT)), in situ soil moisture measurements, and how these data sets impact numerical weather prediction models such as the Global Forecast System of NOAA-NCEP. This study implements the Ensemble Kalman filter in GFS to assimilate the AMSR-E, ASCAT and SMOS soil moisture observations after a quantitative assessment of their error rate based on in situ measurements from ground networks around contiguous United States. in situ soil moisture measurements from ground networks (such as USDA Soil Climate Analysis network - SCAN and NOAA's U.S. Climate Reference Network -USCRN) are used to evaluate the GFS soil moisture simulations (analysis). The benefits and uncertainties of assimilating the satellite data products in GFS are examined by comparing the GFS forecasts of surface temperature and rainfall with and without the assimilations. From these examinations, the advantages of SMOS soil moisture data products over other satellite soil moisture data sets will be evaluated. The next step toward operationally assimilating soil moisture

  10. A Brightness-Temperature-Variance-Based Passive Microwave Algorithm for Monitoring Soil Freeze/Thaw State on the Tibetan Plateau

    Science.gov (United States)

    Han, M.; Yang, K.; Qin, J.; Jin, R.; Ma, Y.; Wen, J.; Chen, Y.; Zhao, L.; La, Z.; Tang, W.

    2014-12-01

    The land surface on the Tibetan Plateau experiences typical diurnal and seasonal freeze/thaw processes that play important roles in the regional water and energy exchanges, and recent passive microwave satellites provide opportunities to detect the soil state for the unique region. With the support of three soil moisture and temperature networks in the Tibetan Plateau, a dual-index microwave algorithm with AMSR-E (Advanced Microwave Scanning Radiometer-Earth Observing System) data is developed for the detection of soil surface freeze/thaw state. One index is the standard deviation index (SDI) of brightness temperature (TB), which is defined as the standard deviation of horizontally polarized brightness temperatures at all AMSR-E frequencies. It is the major index and is used to reflect the reduction of liquid water content after soils get frozen. The other index is the 36.5 GHz vertically-polarized brightness temperature, which is linearly correlated with ground temperature and thus is utilized to detect it. The threshold values of the two indices (SDI and the brightness temperature at 36.5 GHz vertically-polarized) are determined based on a part of in situ data from the network located in a semi-arid climate, and the algorithm was validated against other in situ data from this network. Further validations were conducted based on the other two networks located in different climates (semi-humid and arid, respectively). Results show that this algorithm has accuracy of more than 90% for the semi-humid and semi-arid regions, and misclassifications mainly occur at the transition period between unfrozen and frozen seasons. Nevertheless, the microwave signals have limited capability in identifying the soil surface freeze/thaw state in the arid region, because they can penetrate deep dry soils and thus embody the bulk information beneath the surface.

  11. Prospects on alpine timberline change and its driving mechanism in arid area of Central Asia%亚洲中部干旱区高山林线变化及其驱动机制研究展望

    Institute of Scientific and Technical Information of China (English)

    罗格平; 戴丽; 李艳忠; 鲁蕾

    2011-01-01

    The impact of climate change on forests and the feedback of forests to the climate are the focus of study on global change as well as one of the important research topic in forest ecology. The impact of the global change on forests represents significant regional variation. In the arid area of the Central Asia, the mountainous forests are changing notably with the global warming, especially for the change of the alpine trimline. On the north slope of the Tianshan Mountains with clear vegetation spectrum, the climate changed significantly in the latest 50 years, which is the ideal region for researching changes of the alpine trimline. Photogrammetry and interpretation of the satellite images with high resolution are the new techniques and methods to enhance exploration of alpine trimline change in this area, which is helpful for researching the feature and process of the variations occurring near the forest upper and lower limits of the trimline. Retrieving the key environmental variables, e. G. Soil temperature, soil moisture and canopy temperature, using Landsat TM, Terra/Aqua MODIS and AMSR - E data, meteorological data and ground-based observations can prompt study on the driving mechanism of the trimline change, this will further deepen the understanding of the response of the mountainous forest ecosystem to climate change, and enrich the contents of the forest ecology.%气候变化对森林的影响和森林对气候的反馈作用是全球变化研究前沿,也是森林生态学重要研究方向之一.全球变化对森林的影响存在明显的区域差异,亚洲中部干旱区山地森林在全球变暖背景下正经历着显著变化,其中以高山林线的变化最具代表性.植被带谱清晰的天山北坡近50 a气候变异明显,是研究高山林线变化的理想区域.采用摄影测量技术及高分辨率遥感影像解译手段等新技术、新方法加强对亚洲中部干旱区高山林线变化的探讨,揭示近50 a来亚洲中部干

  12. 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

  13. 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

  14. 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

  15. In vivo effects of Aphanizomenon flos-aquae DC-1 aphantoxins on gas exchange and ion equilibrium in the zebrafish gill

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Delu, E-mail: deluzh@163.com [Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070 (China); Liu, Siyi [Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Jing [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Zhang, Jian Kong [Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070 (China); Hu, Chunxiang, E-mail: deluzh@ihb.ac.cn [Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China); Liu, Yongding [Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072 (China)

    2016-08-15

    Highlights: • Aphantoxins induce respiratory dysfunction in zebrafish gills. • Changes in LDH and cellular ultrastructure indicate gill damage. • Decreased NKA and CA reflect abnormal ion transport and gas exchange. • Increased ROS and decreased T-AOC suggest oxidative stress in the gills. - Abstract: 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 7.61 μg saxitoxin equivalents (eq)/kg (low and high doses, respectively) by intraperitoneal injection. The activities of Na{sup +}-K{sup +}-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 24 h after exposure. Aphantoxins significantly increased the level of ROS and decreased the T-AOC in zebrafish gills from 3 to 12 h 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

  16. 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

  17. A research on the method of deriving high-precision snow parameters from AMSR2 passive microwave remote sensing data%基于AMS R2被动微波积雪参量高精度反演方法研究

    Institute of Scientific and Technical Information of China (English)

    沙依然·外力; 毛炜峄

    2016-01-01

    以新疆为研究区域建立了被动微波遥感积雪深度高精度反演模型,采用高空间和时间分辨率AMSR2被动微波遥感数据(2012年11月-2015年3月逐日数据),结合研究区域海拔高度、坡度、坡向、沙漠,荒漠和地表粗糙度等地形、地貌特征,考虑冰川、水体、林地等地表覆盖类型和不同季节的新雪、干雪和湿雪等积雪属性的微波辐射特征,以决策树阈值法为基础,通过采集样本分类建立起多种雪深判识阈值,在此基础上建立AMSR2高精度积雪深度反演综合模型,分类分析不稳定积雪和冰川信息,从而实现雪深在60 cm以内的积雪深度AMSR2反演的主要原理、思路及方法,并对模型的反演结果跟台站实测或者野外观测积雪值以时间和空间角度进行检验.结果表明:该综合模型能够定量判识研究区域复杂地形地貌条件下的1~60 cm积雪厚度,检验的复相关系数为0.74~0.88,均方根误差为2.92~6.14 cm,平均绝对偏差指数为3~4 cm,雪深误差<5 cm的精度为91%~94%,雪深误差<2.5cm的精度为81%~87%.%This study aims to establish a model of deriving high-precision snow parameters from passive microwave remote sensing data,taken Xinjiang Uygur Autonomous Region as a case.In this paper,firstly high-resolution spatial and temporal data in the research region by means of AMSR2 passive microwave remote sensing were collected from November,2010 to March,2015.Then terrain features,such as altitude,slope,aspect, desert and surface roughness,had also been investigated.Other factors,such as variation of surfaces ranging from glacier,paddy field and forest,and microwave radiations of new snow,dry snow and wet snow in various seasons had also been taken into account.After that,a variety of threshold values to assess snow depth were worked out by classifying the collected samples.Finally,a deriving model of snow

  18. 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.

  19. 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.

  20. 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.

  1. Tetra­aqua­bis­[2-(2-nitro­phen­yl)acetato-κO]cobalt(II)

    Science.gov (United States)

    Danish, Muhammad; Tahir, Muhammad Nawaz; Iftikhar, Sana; Raza, Muhammad Asam; Ashfaq, Muhammad

    2015-01-01

    The mol­ecule of the title compound, [Co(C8H6NO4)2(H2O)4], is centrosymmetric. It is a cobalt(II) complex, bearing two (2-nitro­phen­yl)acetate and four aqua ligands. The coordination around the CoII atom is distorted octa­hedral, defined by four O atoms of water mol­ecules in the equatorial plane and by two carboxyl­ate O atoms at axial positions. The dihedral angles between the benzene ring and the acetate and nitro groups are 61.90 (10) and 19.21 (11)°, respectively. The water mol­ecules form O—H⋯O hydrogen bonds with the nitro and carboxyl­ate groups, leading to a layered structural arrangement parallel to (001). PMID:25844208

  2. 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.

  3. 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.

  4. Simple (17) O NMR method for studying electron self-exchange reaction between UO2 (2+) and U(4+) aqua ions in acidic solution.

    Science.gov (United States)

    Bányai, István; Farkas, Ildikó; Tóth, Imre

    2016-06-01

    (17) O NMR spectroscopy is proven to be suitable and convenient method for studying the electron exchange by following the decrease of (17) O-enrichment in U(17) OO(2+) ion in the presence of U(4+) ion in aqueous solution. The reactions have been performed at room temperature using I = 5 M ClO4 (-) ionic medium in acidic solutions in order to determine the kinetics of electron exchange between the U(4+) and UO2 (2+) aqua ions. The rate equation is given as R = a[H(+) ](-2)  + R', where R' is an acid independent parallel path. R' depends on the concentration of the uranium species according to the following empirical rate equation: R' = k1 [UO(2 +) ](1/2) [U(4 +) ](1/2)  + k2 [UO(2 +) ](3/2) [U(4 +) ](1/2) . The mechanism of the inverse H(+) concentration-dependent path is interpreted as equilibrium formation of reactive UO2 (+) species from UO2 (2+) and U(4+) aqua ions and its electron exchange with UO2 (2+) . The determined rate constant of this reaction path is in agreement with the rate constant of UO2 (2+) -UO2 (+) , one electron exchange step calculated by Marcus theory, match the range given experimentally of it in an early study. Our value lies in the same order of magnitude as the recently calculated ones by quantum chemical methods. The acid independent part is attributed to the formation of less hydrolyzed U(V) species, i.e. UO(3+) , which loses enrichment mainly by electron exchange with UO2 (2+) ions. One can also conclude that (17) O NMR spectroscopy, or in general NMR spectroscopy with careful kinetic analysis, is a powerful tool for studying isotope exchange reactions without the use of sophisticated separation processes. Copyright © 2015 John Wiley & Sons, Ltd.

  5. [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.

  6. Inhibitory effects of deer antler aqua-acupuncture, the pilose antler of Cervus Korean TEMMINCK var mantchuricus Swinhoe, on type II collagen-induced arthritis in rats.

    Science.gov (United States)

    Kim, Yeon-Kye; Kim, Kyung-Sook; Chung, Kang-Hyun; Kim, Jin-Gyu; Kim, Kap-Sung; Lee, Young-Choon; Chang, Young-Chae; Kim, Cheorl-Ho

    2003-07-01

    Water extract of deer antler aqua-acupunture (DAA) prepared from the growing antler of Cervus korean TEMMINCK var. mantchuricus Swinhoe, was used to investigate the efficacy of a traditional immunosuppressive and immuno-activating Korean aqua-acupuncture, on the development of type II collagen (CII)-induced arthritis (CIA) in rats. The onset of arthritis was observed at the 24th day after the CII-immunization in rats, and the severity of CIA was gradually developed. As compared with rats treated with saline, DAA i.p. injected at doses of more than 50 microg/kg once a day for 14 days inhibited the ability of inguinal lymph node cells to produce T cell cytokines interleukin 2 and interferon-gamma when the cells were obtained from rats 24 days after immunization and cultured in vitro with CII. Treatment with DAA also inhibited the production of macrophage cytokines interleukin-1beta, IL-6 and tumor necrosis factor alpha in response to in vitro stimulation of lymph node and macrophage cells with CII. In addition, in order to evaluate the influence of DAA on the incidence and development of arthritis in rat CIA, rats were immunized twice at a 3-week interval with bovine CII, with DAA being given i.p. once a day for 14 days with four different regimens. A 14-day course of DAA treatment at a daily dose of 100 microg/kg, which began on the day of the first CII immunization, suppressed the development of arthritis, as well as antibody formation and delayed-type hypersensitivity to CII. Treatment with DAA, which started on the same day as the booster immunization, also resulted in inhibition of development of arthritis and of immune responses to CII. However, treatment with DAA, which was prophylactically started prior to a primary immunization, did not inhibit the development of arthritis and immune response to CII. Furthermore, DAA extract did not affect the established diseases.

  7. 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.

  8. How Does Mediterranean Basin's Atmosphere Become Weak Moisture Source During Negative Phase of NAO: Use of AIRS, AMSR, TOVS, & TRMM Satellite Datasets Over Last Two NAO Cycles to Examine Governing Controls on E-P

    Science.gov (United States)

    Smith, Eric A.; Mehta, Amita V.

    2008-01-01

    The Mediterranean Sea is a noted 'concentration" basin in that it almost continuously exhibits positive evaporation minus precipitation (E - P ) properties -- throughout the four seasons and from one year to the next. Nonetheless, according to the ECMWF Era-40 48-year (1958-2005) climate reanalysis dataset, for various phases of the North Atlantic Oscillation (NAO) when the pressure gradient between Portugal and Iceland becomes either very relaxed (large negative NAO-Index) or in transition (small positive or negative NAO-Index), the atmospheric moisture source properties of the basin become weak, at times even reversed for several months (i.e., negative E - P). This behavior poses numerous questions concerning how and why these events occur. Moreover, it begs the question of what it would take for the basin to reach its tipping point in which P would exceed E throughout the rainy season (some six months) on an annually persistent basis -- and the sea would possibly transform to a recurring "dilution" basin. This talk investigates these questions by: (1) establishing over a period from 1979 to present, based on detailed analyses of satellite retrieval products from a combination of NASA-AQUA, NOAA-LEO, NASA/JAXA Scatterometer, and NASA-TRMM platforms, plus additional specialized satellite data products and ancillary meteorological datasets, the actual observation-based behavior of E - P, (2) diagnosing the salient physical and meteorological mechanisms that lead to the weaker E - P events during the analysis period, partly based on analyzing surface and upper air data at discrete stations in the western and eastern Mediterranean -- while at the same time evaluating the quality of the ERA-40 data over this same time period, (3) conducting GCM and high-resolution regional modeling experiments to determine if perturbed but realistic meteorological background conditions could maintain Mediterranean as a "dilution" basin through the October to March rainy season on

  9. 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.

  10. Crystal structure of hexa-aqua-nickel(II) bis{2-[(5,6-di-hy-droxy-3-sul-fon-ato-quino-lin-1-ium-7-yl)oxy]acetate} dihydrate.

    Science.gov (United States)

    Le Thi Hong, Hai; Nguyen Thi Ngoc, Vinh; Tran Thi, Da; Nguyen Bich, Ngan; Van Meervelt, Luc

    2015-09-01

    The asymmetric unit of the title compound, [Ni(H2O)6](C11H8NO8S)2·2H2O, features a half-hexa-aqua-nickel(II) complex cation with the Ni(II) ion on an inversion center, one deprotonated 5,6-dihy-droxy-3-sulfoquinolin-7-yloxyacetic acid (QOH) molecule appearing in its zwitterionic form and one lattice water mol-ecule. The sulfonate group is disordered over two positions with occupancy factors of 0.655 (5) and 0.345 (5). The hexa-aqua-nickel(II) cation inter-acts through hydrogen bonding with eight QOH mol-ecules and two water mol-ecules. The six-membered rings of quinoline show π-π stacking [centroid-to-centroid distances of 3.679 (2) Å and 3.714 (2) Å].

  11. Crystal structure of hexa-aqua-nickel(II) bis-{5-bromo-7-[(2-hy-droxy-eth-yl)amino]-1-methyl-6-oxido-quinolin-1-ium-3-sulfonate} monohydrate.

    Science.gov (United States)

    Le Thi Hong, Hai; Nguyen Thi Ngoc, Vinh; Do Thi Van, Anh; Van Meervelt, Luc

    2016-09-01

    The asymmetric unit of the title compound, [Ni(H2O)6](C12H12BrN2O5S)2·H2O, contains a half hexa-aqua-nickel(II) complex cation with the Ni(II) ion lying on an inversion center, one 5-bromo-7-[(2-hy-droxy-eth-yl)amino]-1-methyl-6-oxido-quinolin-1-ium-3-sulfonate (QAO) anion and a half lattice water mol-ecule on a twofold rotation axis. In the crystal, QAO anions are stacked in a column along the c axis by π-π stacking inter-actions [centroid-centroid distances 3.5922 (10)-3.7223 (11) Å]. The columns are inter-linked by hexa-aqua-nickel(II) cations through O-H⋯O and N-H⋯O hydrogen bonds.

  12. 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

  13. Effects of three algae-lysing bacterial strains on growth of Anabaena flos-aquae%3株溶藻菌对水华鱼腥藻生长的效应

    Institute of Scientific and Technical Information of China (English)

    孙秀敏; 郑培忠; 万旗东; 沈健英

    2012-01-01

    The effects of 3 algae-lysing bacterial strains(AL-l,AL-6 and AL-8)on the growth and photosynthetic pigments of Anabaena flos-aquae were determined by spectrophotometry. The results showed that all the 3 bacterial strains could significantly inhibit the growth of A. flos-aquae and their inhibiting effects had a certain correlation to their concentrations. Also the 3 bacterial strains could influence for A. flos-aquae's pigments to absorb light spectrum. The 3 bacterial strains were somewhat different in algae-lysing mode:AL-l and AL-6 indirectly played an algae-lysing role through secreting heat-stable and heat-labile substances while AL-8 played an algae-lysing role directly and indirectly.%以分光光度法测定3株溶藻菌(AL-1、AL-6和AL-8)对水华鱼腥藻(Anabaena flos-aquae)生长效应和光合色素的影响.结果表明:3株溶藻菌均能显著抑制水华鱼腥藻的生长,对其生长速率、干重的抑制效应明显,并表现出一定的浓度相关性;且3株溶藻菌均能影响水华鱼腥藻的色素吸收光谱.3株溶藻菌溶藻方式略有不同,AL-1和AL-6可以通过分泌热稳定的物质和热不稳定的物质间接起到溶藻效果,而AL-8可同时通过直接和间接方式溶藻.

  14. Forest fire danger index based on modifying Nesterov Index, fuel, and anthropogenic activities using MODIS TERRA, AQUA and TRMM satellite datasets

    Science.gov (United States)

    Suresh Babu, K. V.; Roy, Arijit; Ramachandra Prasad, P.

    2016-05-01

    Forest fire has been regarded as one of the major causes of degradation of Himalayan forests in Uttarakhand. Forest fires occur annually in more than 50% of forests in Uttarakhand state, mostly due to anthropogenic activities and spreads due to moisture conditions and type of forest fuels. Empirical drought indices such as Keetch-Byram drought index, the Nesterov index, Modified Nesterov index, the Zhdanko index which belongs to the cumulative type and the Angstrom Index which belongs to the daily type have been used throughout the world to assess the potential fire danger. In this study, the forest fire danger index has been developed from slightly modified Nesterov index, fuel and anthropogenic activities. Datasets such as MODIS TERRA Land Surface Temperature and emissivity (MOD11A1), MODIS AQUA Atmospheric profile product (MYD07) have been used to determine the dew point temperature and land surface temperature. Precipitation coefficient has been computed from Tropical Rainfall measuring Mission (TRMM) product (3B42RT). Nesterov index has been slightly modified according to the Indian context and computed using land surface temperature, dew point temperature and precipitation coefficient. Fuel type danger index has been derived from forest type map of ISRO based on historical fire location information and disturbance danger index has been derived from disturbance map of ISRO. Finally, forest fire danger index has been developed from the above mentioned indices and MODIS Thermal anomaly product (MOD14) has been used for validating the forest fire danger index.

  15. 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.

  16. Global Sea Ice Charting at the National Ice Center

    Science.gov (United States)

    Clemente-Colon, P.

    2006-12-01

    Special Sensor Microwave/Imager (SSM/I) provide better temporal and synoptic view of the Polar Regions albeit at a significantly reduced spatial resolution compared to that of active sensors. Automated SSM/I algorithms provide for near-real time production of sea ice parameters including concentration and multiyear fraction. The retrieval of sea ice drift vectors from passive microwave with SSM/I is operational and it is being also implemented using the Advanced Microwave Scanning Radiometer (AMSR-E), a research instrument available aboard the Aqua satellite. As in the case of QuikSCAT, NIC is also exploring the use of sea ice parameters retrieved from WindSat and the synergy of these observations with the WindSat wind vectors off the MIZ through a newly formed sea ice algorithm working group.

  17. 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

  18. Simulation of snow microwave radiance observations using a coupled land surface- radiative transfer models

    Science.gov (United States)

    Toure, A. M.; Rodell, M.; Hoar, T. J.; Kwon, Y.; Yang, Z.; Zhang, Y.; Beaudoing, H.

    2013-12-01

    Data Assimilation Research Testbed (DART) is the framework that couples CLM4 with the Microwave Emission Model for Layered Snowpacks (MEMLS) to predict Tbs at 6.9, 10.7, 18.7, 23.8, 36.5, and 89.0 GHz, at both vertical and horizontal polarizations. An open-loop experiment simulated Tb over the Northern Hemisphere above 30°N for a 9-year study period and is compared to the observed Tb from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) instrument on the NASA EOS Aqua satellite. In this paper we assess the predicted Tb of the coupled CLM4/MEMLS focusing on the following objectives: 1) the impact of representing snowpack stratigraphy in CLM4; 2) the effect of using the CLM4 sub-grid heterogeneity as metadata in Tbs simulation. Preliminary results on the performance of the RA into DART will also be presented.

  19. 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

  20. 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.

  1. 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

  2. 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).

  3. 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.

  4. Cloud object analysis of CERES Aqua observations of tropical and subtropical cloud regimes: Evolution of cloud object size distributions during the Madden-Julian Oscillation

    Science.gov (United States)

    Xu, Kuan-Man; Wong, Takmeng; Dong, Shengtao; Chen, Feng; Kato, Seiji; Taylor, Patrick C.

    2017-02-01

    In this study, we analyze cloud object data from the Aqua satellite between July 2006 and June 2010 that are matched with the real-time multivariate Madden-Julian Oscillation (MJO) index to examine the impact of MJO evolution on the evolutions of the size distributions of cloud object types. These types include deep convective (DC), cirrostratus, shallow cumulus, stratocumulus and overcast-stratus. A cloud object is a contiguous region of the earth with a single dominant cloud-system type. It is found that the cloud object size distributions of some phases depart greatly from the 8-phase combined distribution at large cloud-object diameters. The large-size group of cloud objects contributes to most of the temporal variations during the MJO evolution. For deep convective and cirrostratus cloud objects, there is a monotonic increase in both the number and footprint of large objects from the depressed to mature phases, which is attributed to the development and maturing of deep convection and anvils. The largest increase in the mean diameter during the mature phases that lasts to the early dissipating phase is related to growth of anvil clouds and is accompanied by moderate decreases in small-size objects. For shallow cumulus, the large objects decrease in number at the mature phases, but increase in number for both sizes before the mature phase. The opposite is true for the large overcast-stratus objects. The temporal evolution of large stratocumulus objects is similar to that of deep convective and cirrostratus object types except for peaking slightly earlier.

  5. 百草枯水剂中百草枯含量测量不确定度评估%Evaluation of Measurement Uncertainty in Determination of Paraquat Content in Paraquat Water Aqua

    Institute of Scientific and Technical Information of China (English)

    朱利利; 裴亭; 包素萍

    2013-01-01

    测定农药百草枯水剂中百草枯的含量,分析评定测量过程的不确定度来源,计算合成不确定度,并给出百草枯测量不确定度表达式.%Content of the herbicide paraquat in Paraquat Water Aqua was determined,sources of uncertainty in the measurement process were identified and evaluated,compound uncertainty was calculated,and a formula for estimating uncertainty in the the measurement of paraquat is provided.

  6. 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

  7. Exploring the impacts of physics and resolution on aqua-planet simulations from a nonhydrostatic global variable-resolution modeling framework: IMPACTS OF PHYSICS AND RESOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chun [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Leung, L. Ruby [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Park, Sang-Hun [National Center for Atmospheric Research, Boulder Colorado USA; Hagos, Samson [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Lu, Jian [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Sakaguchi, Koichi [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Yoon, Jinho [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; School of Earth Sciences and Environmental Engineering, Gwanju Institute of Science and Technology, Gwangju South Korea; Harrop, Bryce E. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Skamarock, William [National Center for Atmospheric Research, Boulder Colorado USA; Duda, Michael G. [National Center for Atmospheric Research, Boulder Colorado USA

    2016-11-04

    Advances in computing resources are gradually moving regional and global numerical forecasting simulations towards sub-10 km resolution, but global high resolution climate simulations remain a challenge. The non-hydrostatic Model for Prediction Across Scales (MPAS) provides a global framework to achieve very high resolution using regional mesh refinement. Previous studies using the hydrostatic version of MPAS (H-MPAS) with the physics parameterizations of Community Atmosphere Model version 4 (CAM4) found notable resolution dependent behaviors. This study revisits the resolution sensitivity using the non-hydrostatic version of MPAS (NH-MPAS) with both CAM4 and CAM5 physics. A series of aqua-planet simulations at global quasi-uniform resolutions ranging from 240 km to 30 km and global variable resolution simulations with a regional mesh refinement of 30 km resolution over the tropics are analyzed, with a primary focus on the distinct characteristics of NH-MPAS in simulating precipitation, clouds, and large-scale circulation features compared to H-MPAS-CAM4. The resolution sensitivity of total precipitation and column integrated moisture in NH-MPAS is smaller than that in H-MPAS-CAM4. This contributes importantly to the reduced resolution sensitivity of large-scale circulation features such as the inter-tropical convergence zone and Hadley circulation in NH-MPAS compared to H-MPAS. In addition, NH-MPAS shows almost no resolution sensitivity in the simulated westerly jet, in contrast to the obvious poleward shift in H-MPAS with increasing resolution, which is partly explained by differences in the hyperdiffusion coefficients used in the two models that influence wave activity. With the reduced resolution sensitivity, simulations in the refined region of the NH-MPAS global variable resolution configuration exhibit zonally symmetric features that are more comparable to the quasi-uniform high-resolution simulations than those from H-MPAS that displays zonal asymmetry in

  8. Anti-bone resorption activity of deer antler aqua-acupunture, the pilose antler of Cervus korean TEMMINCK var. mantchuricus Swinhoe (Nokyong) in adjuvant-induced arthritic rats.

    Science.gov (United States)

    Kim, Kyung-Ho; Kim, Kap-Sung; Choi, Byeong-Joon; Chung, Kang-Hyun; Chang, Young-Chae; Lee, Seung-Duk; Park, Kwan-Kyu; Kim, Hyung-Min; Kim, Cheorl-Ho

    2005-01-15

    Effect of deer antler aqua-acupunture (DAA), prepared from the pilose antler of Cervus korean TEMMINCK var. mantchuricus Swinhoe, a traditional immunosuppressive acupuncture, was evaluated to assess the reductions in bone mass, strength, and turnover in adjuvant-induced arthritic rats. For measuring the above parameters, a 20-day dosing experiment was performed using 6-week-old female Lewis rats. Arthritis was induced by injecting the adjuvant into the hind paw of the Lewis rats. The age-dependent increases in the body weight, lumbar bone mineral content and density (BMC and BMD) and compressive strength were disturbed in the arthritic rats. At 10 days, the histomorphometric parameters of bone formation (BFR/BS and BFR/BV) and the serum osteocalcin levels were significantly reduced compared with the baseline controls of Lewis rats. However, the BMC values corrected for body weight did not differ significantly between the arthritic and normal rats, and the bone minerals were not reduced when they were compared with the baseline controls. At 20 days, the parameters of bone minerals and strength of the lumbar body in the arthritic rats, both with and without correction for body weight, were significantly reduced compared with the baseline controls. The trabecular mineralizing surface remained significantly reduced and the osteoclast numbers were increased. DAA at the doses of 10, 20, 50 and 100 microg/kg, administered by Shinsu (B23) acupuncture daily from the start of the experiment, significantly prevented the development of the chronic paw edema at 20 days. The reductions in the parameters such as bone minerals, strength, and trabecular bone formation, and the increase in osteoclast number were alleviated by this DAA. Age-dependent increases in the lumbar height, disturbed by the adjuvant injection, were also maintained. These results indicated that a 20-day-period is necessary to obtain sufficient reductions in the bone mass and strength of the lumbar body

  9. 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.

  10. Mechanistic investigation of CO2 hydrogenation by Ru(II) and Ir(III) aqua complexes under acidic conditions: two catalytic systems differing in the nature of the rate determining step.

    Science.gov (United States)

    Ogo, Seiji; Kabe, Ryota; Hayashi, Hideki; Harada, Ryosuke; Fukuzumi, Shunichi

    2006-10-21

    Ruthenium aqua complexes [(eta(6)-C(6)Me(6))Ru(II)(L)(OH(2))](2+) {L = bpy (1) and 4,4'-OMe-bpy (2), bpy = 2,2'-bipyridine, 4,4'-OMe-bpy = 4,4'-dimethoxy-2,2'-bipyridine} and iridium aqua complexes [Cp*Ir(III)(L)(OH(2))](2+) {Cp* = eta(5)-C(5)Me(5), L = bpy (5) and 4,4'-OMe-bpy (6)} act as catalysts for hydrogenation of CO(2) into HCOOH at pH 3.0 in H(2)O. The active hydride catalysts cannot be observed in the hydrogenation of CO(2) with the ruthenium complexes, whereas the active hydride catalysts, [Cp*Ir(III)(L)(H)](+) {L = bpy (7) and 4,4'-OMe-bpy (8)}, have successfully been isolated after the hydrogenation of CO(2) with the iridium complexes. The key to the success of the isolation of the active hydride catalysts is the change in the rate-determining step in the catalytic hydrogenation of CO(2) from the formation of the active hydride catalysts, [(eta(6)-C(6)Me(6))Ru(II)(L)(H)](+), to the reactions of [Cp*Ir(III)(L)(H)](+) with CO(2), as indicated by the kinetic studies.

  11. 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...

  12. 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

  13. 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...

  14. 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.

  15. 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

  16. Aqua: Current Status and Future

    Science.gov (United States)

    Oreopoulos, Lazaros; Parkinson, Claire L.

    2014-01-01

    This document was presented at the NASA Sounder Science Team Meeting held in Greenbelt, MD, September 30-October 2, 2014. The organizers of the meeting plan to post the presentations to a public website.

  17. 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...

  18. 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.

  19. Evaluation of microwaves soil moisture products based on two years of ground measurements over a Sahelian region.

    Science.gov (United States)

    Gruhier, C.; de Rosnay, P.; Kerr, Y.; Kergoat, L.

    2008-12-01

    Microwaves remote sensing is a promising approach to measure soil moisture values and variations. Soil moisture is a very important variable which strongly interacts with soil-vegetation-atmosphere fluxes. This is particularly true in Sahelian region with monsoon climatic system. From active or passive microwaves measurements of backscatter coefficients or brightness temperatures, soil moisture products are derived. Soil moisture products evaluation is essential to improve algorithm and inform users on the products quality (eg quality of soil moisture products variability or absolutes). This study aims to evaluate and to intercompare five soil moisture products from active and passive microwaves sensors. The study is performed for 2005-2006, for a 1 x 3 degrees longitude-latitude window located in Sahel (14-17N and 0-1W). In addition an accurate validation is conducted for specific locations based on ground measurements available in this region. It uses the Gourma (Mali) soil moisture measurements network installed in the framework of the African Monsoon Multidisciplinary Analysis (AMMA) program. The soil moisture network has been organized in order to validate remotely sensed soil moisture for the future Soil Moisture an Ocean Salinity (SMOS) mission. Three stations located on sandy dune systems have been selected according to their location along the North-South climatic gradient. They provide continuous soil moisture measurements at 15-minute time step and at 5-cm depth for 2005-2006. Five soil moisture products provided by three different sensors are considered. 1) From the Advanced Microwave Scanning Radiometer on Earth Observing System (AMSR-E), two soil moisture products are used: the National Snow and Ice Data Center product and the Amsterdam University product. 2) From the Wind Scatterometer, on European Remote Sensing (ERS) satellite, two soil moisture products are evaluated: the Vienna University of Technology and the Zribi et al 2007 products. 3) The

  20. 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

  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. Temporal evolution of the snow density near the surface at Dome C on Antarctica Plateau

    Science.gov (United States)

    Champollion, N.; Picard, G.; Arnaud, L.; Macelloni, G.; Remy, F.

    2014-12-01

    Snow density near the surface, i.e. the first 5 - 10 first centimeters, is essential for surface mass balance retrieval from satellite or stakes, thermal diffusion for surface energy budget, firn densification for ice-core interpretation and air / snow chemistry exchange on ice sheets. It is related to the local meteorological conditions such as precipitation, wind and temperature (metamorphism). A long term temporal and spatial evolution of the snow density near the surface on ice sheets could be use to monitor climate evolution. Passive and active microwave offer the possibility to study recent climate evolution with respectively 30 and 20 years of measurements, a very good temporal repeatability and a large spatial coverage. The aim of this paper is (1) to derive the snow density near the surface, called "surface snow density", from AMSR-E passive microwave observations and ENVISAT radar altimetry measurements, and (2) to study the temporal evolution of this density. Surface snow density is also jointly estimated from passive microwave observations and radar altimetry measurements by two independent methods. For both methods, the estimation of density is based on the surface reflection of electromagnetic wave in the microwave domain, which mainly depends on dielectric contrast between air and snow. For passive microwave observations, the polarization ratio is derived in order to be most sensitive to snow density variations near the surface. Then, the Dense Media Radiative Transfer theory is used for modeling and quantify the relationship between polarization ratio and surface snow density. For radar altimetry measurements, the total microwave backscatter coefficient is used because it depends on surface snow density and roughness. Validation of the surface snow density estimations is performed at Dome C on the Antarctica Plateau from in situ measurements of snow density. Uncertainties about the two retrieval methods (from AMSR-E and ENVISAT observations) are

  3. Arctic Mechanisms of Interaction between the Surface and Atmosphere (AMISA) IPY Airborne Data Set

    Science.gov (United States)

    Gasiewski, A. J.; Zucker, M. L.; Persson, O. P.

    2012-12-01

    of radiance, thermodynamic and cloud variables over wide areas using in situ cloud probes, dropsondes, and nadir and zenith staring microwave radiometric measurements (including temperature profiling). The DC-8 measurements occurred over and in the vicinity of the Swedish ice breaker Oden fielded under the ASCOS project. The AMISA observations are currently being calibrated and studied to understand the impact of mesoscale, turbulent, and aerosol-driven atmospheric processes on surface-energy transition-to-freezeup conditions. The passive microwave imagery is are also being used to improve the NASA AMSR-E sea ice algorithm during summertime Arctic conditions, specifically, to understand the effects of clouds on AMSR-E sea ice signatures.

  4. 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

  5. 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

  6. Comparison of remote sensing data with in-situ wind observation during the development of the South China Sea monsoon

    Institute of Scientific and Technical Information of China (English)

    LI Jian; WANG Dongxiao; CHEN Ju; YANG Lei

    2012-01-01

    Wind measurements derived from QuikSCAT data were compared with those measured by anemometer on Yongxing Island in the South China Sea (SCS) for the period from April 2008 to November 2009.The comparison confirms that QuikSCAT estimates of wind speed and direction are generally accurate,except for the extremes of high wind speeds (>13.8 m/s) and very low wind speeds (<1.5 m/s)where direction is poorly predicted.In-situ observations show that the summer monsoon in the northern S CS starts between May 6 and June 1.From March 13,2010 to August 31,2010,comparisons of sea surface temperature (SST) and rainfall from AMSR-E with data from a buoy located at Xisha Islands,as well as wind measurements derived from ASCAT and observations from an automatic weather station show that QuikSCAT,ASCAT and AMSR-E data are good enough for research.It is feasible to optimize the usage of remote-sensing data if validated with in-situ measurements.Remarkable changes were observed in wind,barometric pressure,humidity,outgoing longwave radiation (OLR),air temperature,rainfall and SST during the monsoon onset.The eastward shift of western Pacific subtropical high and the southward movement of continental cold front preceded the monsoon onset in SCS.The starting dates of SCS summer monsoon indicated that the southwest monsoon starts in the Indochinese Peninsula and forms an eastward zonal belt,and then the belt bifurcates in the SCS,with one part moving northeastward into the tropical western North Pacific,and another southward into western Kalimantan.This largely determined the pattern of the SCS summer monsoon.Wavelet analysis of zonal wind and OLR at Xisha showed that intra-seasonal variability played an important role in the summer.This work improves the accuracy of the amplitude of intra-seasonal and synoptic variation obtained from remote-sensed data.

  7. Evaluating the Performance of a Soil Moisture Data Assimilation System for Agricultural Drought Monitoring

    Science.gov (United States)

    Han, E.; Crow, W. T.; Holmes, T. R.; Bolten, J. D.

    2013-12-01

    Despite considerable interest in the application of land surface data assimilation systems (LDAS) for agricultural drought applications, relatively little is known about the large-scale performance of such systems and, thus, the optimal methodological approach for implementing them. To address this need, we evaluates a soil moisture assimilation system for agricultural drought monitoring by benchmarking each component of the system (i.e., a satellite soil moisture retrieval algorithm, a soil water balance model and a sequential data assimilation filter) against a series of linear models which perform the same function (i.e., have the same basic inputs/output) as the full component. Lagged soil moisture/NDVI correlations obtained using individual LDAS components versus their linear analogs reveal the degree to which non-linearities and/or complexities contained within each component actually contribute to the performance of the LDAS system as a whole. Here, a particular system based on surface soil moisture retrievals from the Land Parameter Retrieval Model (LPRM), a two-layer Palmer soil water balance model and an Ensemble Kalman filter (EnKF) is benchmarked. Results suggest significant room for improvement in each component of the system. First, the non-linear LPRM retrieval algorithm does not appear to add much additional predictive information for future NDVI compared to the simple linear benchmark model comprised of initial AMSR-E observations (horizontally and vertically polarized brightness temperatures and surface temperature). Second, the Palmer model performed worse than the purely linear prognostic model (Antecedent Precipitation Index model) in predicting future vegetation condition. This result points out that the saturation threshold of soil layers in the modern LSMs for runoff generation hinders maximum utilization of meteorological input information for agricultural drought monitoring. As to the assimilation algorithm, better performance of the

  8. Assessment of NASA GISS CMIP5 and Post-CMIP5 Simulated Clouds and TOA Radiation Budgets Using Satellite Observations. Part I: Cloud Fraction and Properties

    Science.gov (United States)

    Stanfield, Ryan E.; Dong, Xiquan; Xi, Baike; Kennedy, Aaron; Del Genio, Anthony D.; Minnia, Patrick; Jiang, Jonathan H.

    2014-01-01

    Although many improvements have been made in phase 5 of the Coupled Model Intercomparison Project (CMIP5), clouds remain a significant source of uncertainty in general circulation models (GCMs) because their structural and optical properties are strongly dependent upon interactions between aerosol/cloud microphysics and dynamics that are unresolved in such models. Recent changes to the planetary boundary layer (PBL) turbulence and moist convection parameterizations in the NASA GISS Model E2 atmospheric GCM(post-CMIP5, hereafter P5) have improved cloud simulations significantly compared to its CMIP5 (hereafter C5) predecessor. A study has been performed to evaluate these changes between the P5 and C5 versions of the GCM, both of which used prescribed sea surface temperatures. P5 and C5 simulated cloud fraction (CF), liquid water path (LWP), ice water path (IWP), cloud water path (CWP), precipitable water vapor (PWV), and relative humidity (RH) have been compared to multiple satellite observations including the Clouds and the Earth's Radiant Energy System-Moderate Resolution Imaging Spectroradiometer (CERES-MODIS, hereafter CM), CloudSat- Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO; hereafter CC), Atmospheric Infrared Sounder (AIRS), and Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E). Although some improvements are observed in the P5 simulation on a global scale, large improvements have been found over the southern midlatitudes (SMLs), where correlations increased and both bias and root-mean-square error (RMSE) significantly decreased, in relation to the previous C5 simulation, when compared to observations. Changes to the PBL scheme have resulted in improved total column CFs, particularly over the SMLs where marine boundary layer (MBL) CFs have increased by nearly 20% relative to the previous C5 simulation. Globally, the P5 simulated CWPs are 25 gm22 lower than the previous C5 results. The P5 version of the

  9. Crystal structure of catena-poly[bis-(tetra-ethyl-ammonium) [tetra-aqua-tris(μ-dicyanamido-κ(2)N(1):N(5))bis(dicyanamido-κN(1))di-cobaltate(II)] dicyanamide].

    Science.gov (United States)

    Liu, Chen; Thuijs, Annaliese E; Abboud, Khalil A

    2016-11-01

    The structure of the title compound, [N(C2H5)4]2[Co2(C2N3)5(H2O)4](C2N3), is a new example of a metal-dicyanamide coordination polymer which exhibits a unique three-dimensional framework of covalently linked Co(II) chains. All bridging dicyanamide ligands in the title structure are in the μ1,5-bridging mode. The anionic Co(II)-dicyanamide network is templated by tetra-ethyl-ammonium cations residing in a series of channels extending along the b axis where additional non-coordinating dicyanamidate anions are also located. The framework structure is further stabilized by O-H⋯N hydrogen bonding between aqua ligands and dicyanamido ligands or the dicyanamide anion. In addition, C-H⋯N inter-actions are present between the tetra-ethyl-ammonium cations and dicyanamide amide nitro-gen atoms.

  10. Talking about the design concept of large-scale commercial building with Nanjing Aqua city as an example%以南京水游城为例谈大型商业建筑设计思想

    Institute of Scientific and Technical Information of China (English)

    陈卓

    2012-01-01

    针对南京水游城这个大型商业建筑项目进行了研究,分析了该项目与传统商业建筑设计理念的差别,阐述了该商业建筑整体性特点和人性化的设计原则,并总结其独特的设计手法,以期指导今后同类建筑设计。%The paper studies the large-scale commercial building project of Nanjing Aqua city, analyzes the design concept difference of the project and the traditional commercial building, describes the integrity characteristics and personal design principles of the commercial building, and summarizes its unique design tactics, with a view to guide similar building design in future.

  11. Lidar Ratios for Dust Aerosols Derived From Retrievals of CALIPSO Visible Extinction Profiles Constrained by Optical Depths from MODIS-Aqua and CALIPSO/CloudSat Ocean Surface Reflectance Measurements

    Science.gov (United States)

    Young, Stuart A.; Josset, Damien B.; Vaughan, Mark A.

    2010-01-01

    CALIPSO's (Cloud Aerosol Lidar Infrared Pathfinder Satellite Observations) analysis algorithms generally require the use of tabulated values of the lidar ratio in order to retrieve aerosol extinction and optical depth from measured profiles of attenuated backscatter. However, for any given time or location, the lidar ratio for a given aerosol type can differ from the tabulated value. To gain some insight as to the extent of the variability, we here calculate the lidar ratio for dust aerosols using aerosol optical depth constraints from two sources. Daytime measurements are constrained using Level 2, Collection 5, 550-nm aerosol optical depth measurements made over the ocean by the MODIS (Moderate Resolution Imaging Spectroradiometer) on board the Aqua satellite, which flies in formation with CALIPSO. We also retrieve lidar ratios from night-time profiles constrained by aerosol column optical depths obtained by analysis of CALIPSO and CloudSat backscatter signals from the ocean surface.

  12. 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.

  13. 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.

    2015-01-01

    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.

  14. Analysis of PSR Microwave Observations during SMEX04

    Science.gov (United States)

    Bindlish, R.; Jackson, T. J.; Gasiewski, A. J.; Stankov, B. B.; Klein, M.

    2005-05-01

    The Polarimetric Scanning Radiometer (PSR/CX) was flown on a P-3B aircraft as part of SMEX04. PSR/CX has been successfully operated during several previous airborne campaigns. The primary objectives of PSR/CX during SMEX04 are: 1) Contribute to the calibration and validation of AMSR observations over different parts of the globe and to check for the presence of Radio Frequency Interference (RFI), 2) Explore the potential for the development of soil moisture retrieval algorithms using C-band imagery in diverse landscapes (Arizona and Sonora, Mexico), and 3) to develop retrieval algorithms to estimate soil moisture over areas of topographic variability and vegetation. The dominant landuse classes in the different SMEX04 domains are: 1) Arizona - semi-arid climate with sparse vegetation and moderate topography, and 2) Sonora, Mexico - moderate vegetation with strong topographic gradients. SMEX04 consisted of about 84 flightlines at high altitude resulting in 21 mapping domains flown during August, 2004 (11 over Arizona and 10 over Sonora). Each mapping domain is about 75 km x 50 km, providing an excellent area for calibration and validation of AMSR-E observations. Some areas of the SMEX04 domain received heavy localized precipitation as a result of convective activity during the experiment. These resulted in interesting brightness temperature patterns with strong brightness temperature gradients. The presence of these diverse conditions will help address questions relating to scaling of spaceborne microwave observations. Results of comparison between PSR and AMSR and the use of microwave remote sensing to estimate soil moisture over wide range of vegetation and soil moisture conditions are also presented.

  15. 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.

  16. 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

  17. Temporal Stability of Soil Moisture and Radar Backscatter Observed by the Advanced Synthetic Aperture Radar (ASAR).

    Science.gov (United States)

    Wagner, Wolfgang; Pathe, Carsten; Doubkova, Marcela; Sabel, Daniel; Bartsch, Annett; Hasenauer, Stefan; Blöschl, Günter; Scipal, Klaus; Martínez-Fernández, José; Löw, Alexander

    2008-02-21

    The high spatio-temporal variability of soil moisture is the result of atmosphericforcing and redistribution processes related to terrain, soil, and vegetation characteristics.Despite this high variability, many field studies have shown that in the temporal domainsoil moisture measured at specific locations is correlated to the mean soil moisture contentover an area. Since the measurements taken by Synthetic Aperture Radar (SAR)instruments are very sensitive to soil moisture it is hypothesized that the temporally stablesoil moisture patterns are reflected in the radar backscatter measurements. To verify this hypothesis 73 Wide Swath (WS) images have been acquired by the ENVISAT AdvancedSynthetic Aperture Radar (ASAR) over the REMEDHUS soil moisture network located inthe Duero basin, Spain. It is found that a time-invariant linear relationship is well suited forrelating local scale (pixel) and regional scale (50 km) backscatter. The observed linearmodel coefficients can be estimated by considering the scattering properties of the terrainand vegetation and the soil moisture scaling properties. For both linear model coefficients,the relative error between observed and modelled values is less than 5 % and thecoefficient of determination (R²) is 86 %. The results are of relevance for interpreting anddownscaling coarse resolution soil moisture data retrieved from active (METOP ASCAT)and passive (SMOS, AMSR-E) instruments.

  18. 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.

  19. Using image reconstruction methods to enhance gridded resolutionfor a newly calibrated passive microwave climate data record

    Science.gov (United States)

    Paget, A. C.; Brodzik, M. J.; Gotberg, J.; Hardman, M.; Long, D. G.

    2014-12-01

    Spanning over 35 years of Earth observations, satellite passive microwave sensors have generated a near-daily, multi-channel brightness temperature record of observations. Critical to describing and understanding Earth system hydrologic and cryospheric parameters, data products derived from the passive microwave record include precipitation, soil moisture, surface water, vegetation, snow water equivalent, sea ice concentration and sea ice motion. While swath data are valuable to oceanographers due to the temporal scales of ocean phenomena, gridded data are more valuable to researchers interested in derived parameters at fixed locations through time and are widely used in climate studies. We are applying recent developments in image reconstruction methods to produce a systematically reprocessed historical time series NASA MEaSUREs Earth System Data Record, at higher spatial resolutions than have previously been available, for the entire SMMR, SSM/I-SSMIS and AMSR-E record. We take advantage of recently released, recalibrated SSM/I-SSMIS swath format Fundamental Climate Data Records. Our presentation will compare and contrast the two candidate image reconstruction techniques we are evaluating: Backus-Gilbert (BG) interpolation and a radiometer version of Scatterometer Image Reconstruction (SIR). Both BG and SIR use regularization to trade off noise and resolution. We discuss our rationale for the respective algorithm parameters we have selected, compare results and computational costs, and include prototype SSM/I images at enhanced resolutions of up to 3 km. We include a sensitivity analysis for estimating sensor measurement response functions critical to both methods.

  20. Seven Years of Advanced Synthetic Aperture Radar (ASAR Global Monitoring (GM of Surface Soil Moisture over Africa

    Directory of Open Access Journals (Sweden)

    Alena Dostálová

    2014-08-01

    Full Text Available A surface soil moisture (SSM product at a 1-km spatial resolution derived from the Envisat Advanced Synthetic Aperture Radar (ASAR Global Monitoring (GM mode data was evaluated over the entire African continent using coarse spatial resolution SSM acquisitions from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E and the Noah land surface model from the Global Land Data Assimilation System (GLDAS-NOAH. The evaluation was performed in terms of relative soil moisture values (%, as well as anomalies from the seasonal cycle. Considering the high radiometric noise of the ASAR GM data, the SSM product exhibits a good ability (Pearson correlation coefficient (R = ~0.6 for relative soil moisture values and root mean square difference (RMSD = 11% when averaged to 5-km resolution to monitor temporal soil moisture variability in regions with low to medium density vegetation and yearly rainfall >250 mm. The findings agree with previous evaluation studies performed over Australia and further strengthen the understanding of the quality of the ASAR GM SSM product and its potential for data assimilation. Problems identified in the ASAR GM algorithm over arid regions were explained by azimuthal effects. Diverse backscatter behavior over different soil types was identified. The insights gained about the quality of the data were used to establish a reliable masking of the existing ASAR GM SSM product and the identification of areas where further research is needed for the future Sentinel-1-derived SSM products.

  1. Aerosol optical depth under "clear" sky conditions derived from sea surface reflection of lidar signals.

    Science.gov (United States)

    He, Min; Hu, Yongxiang; Huang, Jian Ping; Stamnes, Knut

    2016-12-26

    There are considerable demands for accurate atmospheric correction of satellite observations of the sea surface or subsurface signal. Surface and sub-surface reflection under "clear" atmospheric conditions can be used to study atmospheric correction for the simplest possible situation. Here "clear" sky means a cloud-free atmosphere with sufficiently small aerosol particles. The "clear" aerosol concept is defined according to the spectral dependence of the scattering cross section on particle size. A 5-year combined CALIPSO and AMSR-E data set was used to derive the aerosol optical depth (AOD) from the lidar signal reflected from the sea surface. Compared with the traditional lidar-retrieved AOD, which relies on lidar backscattering measurements and an assumed lidar ratio, the AOD retrieved through the surface reflectance method depends on both scattering and absorption because it is based on two-way attenuation of the lidar signal transmitted to and then reflected from the surface. The results show that the clear sky AOD derived from the surface signal agrees with the clear sky AOD available in the CALIPSO level 2 database in the westerly wind belt located in the southern hemisphere, but yields significantly higher aerosol loadings in the tropics and in the northern hemisphere.

  2. Evaluation of a physically-based snow model with infrared and microwave satellite-derived estimates

    Science.gov (United States)

    Wang, L.

    2013-05-01

    Snow (with high albedo, as well as low roughness and thermal conductivity) has significant influence on the land-atmosphere interactions in the cold climate and regions of high elevation. The spatial and temporal variability of the snow distribution on a basin scale greatly determines the timing and magnitude of spring snowmelt runoff. For improved water resources management, a physically-based distributed snow model has been developed and applied to the upper Yellow River Basin to provide the outputs of snow variables as well as streamflows from 2001 to 2005. Remotely-sensed infrared information from MODIS satellites has been used to evaluate the model's outputs of spatially-distributed snow cover extent (SCE) and land surface temperature (LST); while the simulated snow depth (SD) and snow water equivalent (SWE) have been compared with the microwave information from SSM/I and AMSR-E satellites. In general, the simulated streamflows (including spring snowmelt) agree fairly well with the gauge-based observations; while the modeled snow variables show acceptable accuracies through comparing to various satellite-derived estimates from infrared or microwave information.;

  3. 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

    Science.gov (United States)

    Shofiyati, Rizatus; Takeuchi, Wataru; Sofan, Parwati; Darmawan, Soni; Awaluddin; Supriatna, Wahyu

    2014-06-01

    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.

  4. Evaluation of drought indices via remotely sensed data with hydrological variables

    Science.gov (United States)

    Choi, Minha; Jacobs, Jennifer M.; Anderson, Martha C.; Bosch, David D.

    2013-01-01

    SummaryAn intercomparison among standard and remotely sensed drought indices was conducted using streamflow and soil moisture measurements collected in the Little River Experimental Watershed, Georgia, US, during the period from 2000 to 2008. All drought indices exhibited a linear, monotonic association with soil moisture, but there was a non-linear monotonic association between the drought indices and streamflow. Of the indices examined, the Evaporative Stress Index (ESI) showed reasonable performance with about 90% accuracy capturing moderate drought conditions and 80% accuracy capturing severe drought conditions in comparison to observed soil moisture and streamflow. While the ability of the ESI to capture shorter term droughts is equal or superior to the Palmer Drought Severity Index (PDSI) when characterizing droughts based on soil moisture and streamflow thresholds, the accuracy of the ESI was less efficient in the case of severe droughts. A drought index developed from the Advanced Microwave Scanning Radiometer (AMSR-E) soil moisture product showed reasonable correlations with the observed soil moisture and streamflow. However the ESI, Vegetation Health Index (VHI), and PDSI demonstrated greater skill in detecting drought in this study region. Multi-variable linear regression models revealed that the joint use of PDSI and appropriate remote sensing products improved predictions of observed hydrologic variables. Overall, the ESI was identified as a promising drought index for characterizing streamflow and soil moisture anomalies, particularly in regions where precipitation observations are unavailable, sparsely distributed, or biased with respect to regional averages.

  5. [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.

  6. 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.

  7. Atmospheric Influences Analysis on the Satellite Passive Microwave Remote Sensing%大气对星载被动微波影响分析研究

    Institute of Scientific and Technical Information of China (English)

    邱玉宝; 石利娟; 施建成; 赵少杰

    2016-01-01

    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 radia-tion 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 (<18.7 GHz) and the microwave brightness temperature changes caused by atmosphere can be ignored in clear sky condition .Atmospheric transmit-tances at 36.5 and 89 GHz were 0.896 and 0.756 respectively .The effects of atmospheric water 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 stra-tus 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 micro-wave atmospheric correction algorithm development .Finally ,the atmospheric sounding data was utilized to calculate the atmos-pheric transmittance of Hailaer Region ,Inner Mongolia province ,in July 2013 .The results indicated that atmospheric transmit-tances were close

  8. 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.

  9. The impact of snow depth, snow density and ice density on sea ice thickness retrieval from satellite radar altimetry: results from the ESA-CCI Sea Ice ECV Project Round Robin Exercise

    Science.gov (United States)

    Kern, S.; Khvorostovsky, K.; Skourup, H.; Rinne, E.; Parsakhoo, Z. S.; Djepa, V.; Wadhams, P.; Sandven, S.

    2015-01-01

    We assess different methods and input parameters, namely snow depth, snow density and ice density, used in freeboard-to-thickness conversion of Arctic sea ice. This conversion is an important part of sea ice thickness retrieval from spaceborne altimetry. A data base is created comprising sea ice freeboard derived from satellite radar altimetry between 1993 and 2012 and co-locate observations of total (sea ice + snow) and sea ice freeboard from the Operation Ice Bridge (OIB) and CryoSat Validation Experiment (CryoVEx) airborne campaigns, of sea ice draft from moored and submarine upward looking sonar (ULS), and of snow depth from OIB campaigns, Advanced Microwave Scanning Radiometer (AMSR-E) and the Warren climatology (Warren et al., 1999). We compare the different data sets in spatiotemporal scales where satellite radar altimetry yields meaningful results. An inter-comparison of the snow depth data sets emphasizes the limited usefulness of Warren climatology snow depth for freeboard-to-thickness conversion under current Arctic Ocean conditions reported in other studies. We test different freeboard-to-thickness and freeboard-to-draft conversion approaches. The mean observed ULS sea ice draft agrees with the mean sea ice draft derived from radar altimetry within the uncertainty bounds of the data sets involved. However, none of the approaches are able to reproduce the seasonal cycle in sea ice draft observed by moored ULS. A sensitivity analysis of the freeboard-to-thickness conversion suggests that sea ice density is as important as snow depth.

  10. 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.

  11. Annual Snow Assessments Using Multi-spectral and Passive Microwave Remote Sensing

    Science.gov (United States)

    Daly, S. F.; Vuyovich, C. M.; Deeb, E. J.; Newman, S. D.; Baldwin, T. B.

    2010-12-01

    Since the winter season of 2004-2005, annual snow assessments have been conducted for regions across the Middle East (including Eastern Turkey, Afghanistan, and Pakistan) using multispectral (AVHRR and MODIS) and passive microwave (SSM/I and AMSR-E) remote sensing technologies. Due to limited ground-based observations of precipitation and snow pack conditions, remote sensing provides a unique opportunity to assess these conditions at different scales and offer an appraisal of the current conditions in an historical context. During each winter season, bi-weekly snow products and assessments are produced including: current Snow Covered Area (SCA) at regional and watershed scales; estimation of SCA by elevation band; current snowpack total Snow Water Equivalent (SWE) for each watershed with an historical perspective (1987-present); snow condition outlook by watershed; general summary of snow conditions based on remote sensing products and limited ground-based observations; and if warranted, a snow melt flooding advisory. Most recently, the winter 2009-2010 season provided interesting aspects that are further investigated: comparison of reported drought conditions, SCA extents, and passive microwave SWE estimates in Afghanistan; flooding event in Northeastern Afghanistan perhaps due to late season snow fall and subsequent snow melt; lower SCA in Eastern Turkey throughout winter despite heavy precipitation perhaps explained by warmer regional temperatures.

  12. Analysis of net primary productivity of terrestrial vegetation on the Qinghai-Tibet Plateau, based on MODIS remote sensing data

    Institute of Scientific and Technical Information of China (English)

    CHEN ZhuoQi; SHAO QuanQin; LIU JiYuan; WANG JunBang

    2012-01-01

    GLO-PEM is driven by soil moisture data of AMSR-E and PAR (Photosynthetically active radiation) which is retrieved from MODIS atmospheric data product in this paper.Using remote sensing data can overcome uncertainty brought from interpolation of precipitation and PAR.Comparing with observed radiation data,PAR retrieved by remote sensing is in high accuracy in this study.RMSE is 9 and 19.68 W m-2 and R2 is 0.89 and 0.67 respectively.As a result of GLO-PEM,annual total amount of NPP of Qinghai-Tibet Plateau is 0.37 Pg C a-1 in 2005-2008.There is a significant linear relationship between field and simulated NPP.Determination coefficient reached 0.93.NPP is decrease from southeast to northwest in the Qinghai-Tibet Plateau.NPP changes from 0 to 1500 g C m-2 a-1.There is different limit factors of vegetation growth in west and east plateau.In the west of 450 mm rainfall line,the limit factors is precipitation.In the east of 450 mm rainfall line,temperature is the dominated factor of vegetation growth.

  13. Constraining cloud lifetime effects of aerosols using A-Train satellite observations

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Minghuai; Ghan, Steven J.; Liu, Xiaohong; Ecuyer, Tristan L.; Zhang, Kai; Morrison, H.; Ovchinnikov, Mikhail; Easter, Richard C.; Marchand, Roger; Chand, Duli; Qian, Yun; Penner, Joyce E.

    2012-08-15

    Aerosol indirect effects have remained the largest uncertainty in estimates of the radiative forcing of past and future climate change. Observational constraints on cloud lifetime effects are particularly challenging since it is difficult to separate aerosol effects from meteorological influences. Here we use three global climate models, including a multi-scale aerosol-climate model PNNL-MMF, to show that the dependence of the probability of precipitation on aerosol loading, termed the precipitation frequency susceptibility (S{sub pop}), is a good measure of the liquid water path response to aerosol perturbation ({lambda}), as both Spop and {lambda} strongly depend on the magnitude of autoconversion, a model representation of precipitation formation via collisions among cloud droplets. This provides a method to use satellite observations to constrain cloud lifetime effects in global climate models. S{sub pop} in marine clouds estimated from CloudSat, MODIS and AMSR-E observations is substantially lower than that from global climate models and suggests a liquid water path increase of less than 5% from doubled cloud condensation nuclei concentrations. This implies a substantially smaller impact on shortwave cloud radiative forcing (SWCF) over ocean due to aerosol indirect effects than simulated by current global climate models (a reduction by one-third for one of the conventional aerosol-climate models). Further work is needed to quantify the uncertainties in satellite-derived estimates of S{sub pop} and to examine S{sub pop} in high-resolution models.

  14. Cyclone impact on sea ice in the central Arctic Ocean: a statistical study

    Directory of Open Access Journals (Sweden)

    A. Kriegsmann

    2013-03-01

    Full Text Available This study investigates the impact of cyclones on the Arctic Ocean sea ice for the first time in a statistical manner. We apply the coupled ice–ocean model NAOSIM which is forced by the ECMWF analyses for the period 2006–2008. Cyclone position and radius detected in the ECMWF data are used to extract fields of wind, ice drift, and concentration from the ice–ocean model. Composite fields around the cyclone centre are calculated for different cyclone intensities, the four seasons, and different regions of the Arctic Ocean. In total about 3500 cyclone events are analyzed. In general, cyclones reduce the ice concentration on the order of a few percent increasing towards the cyclone centre. This is confirmed by independent AMSR-E satellite data. The reduction increases with cyclone intensity and is most pronounced in summer and on the Siberian side of the Arctic Ocean. For the Arctic ice cover the impact of cyclones has climatologic consequences. In winter, the cyclone-induced openings refreeze so that the ice mass is increased. In summer, the openings remain open and the ice melt is accelerated via the positive albedo feedback. Strong summer storms on the Siberian side of the Arctic Ocean may have been important reasons for the recent ice extent minima in 2007 and 2012.

  15. 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.

  16. Sensitivity of the Arctic sea ice concentration forecasts to different atmospheric forcing:a case study

    Institute of Scientific and Technical Information of China (English)

    YANG Qinghua; LIU Jiping; ZHANG Zhanhai; SUI Cuijuan; XING Jianyong; LI Ming; LI Chunhua; ZHAO Jiechen; ZHANG Lin

    2014-01-01

    A regional Arctic configuration of the Massachusetts Institute of Technology general circulation model (MIT-gcm) is used as the coupled ice-ocean model for forecasting sea ice conditions in the Arctic Ocean at the Na-tional Marine Environmental Forecasting Center of China (NMEFC), and the numerical weather prediction from the National Center for Environmental Prediction Global Forecast System (NCEP GFS) is used as the atmospheric forcing. To improve the sea ice forecasting, a recently developed Polar Weather Research and Forecasting model (Polar WRF) model prediction is also tested as the atmospheric forcing. Their forecasting performances are evaluated with two different satellite-derived sea ice concentration products as initializa-tions: (1) the Special Sensor Microwave Imager/Sounder (SSMIS) and (2) the Advanced Microwave Scanning Radiometer for EOS (AMSR-E). Three synoptic cases, which represent the typical atmospheric circulations over the Arctic Ocean in summer 2010, are selected to carry out the Arctic sea ice numerical forecasting experiments. The evaluations suggest that the forecasts of sea ice concentrations using the Polar WRF atmo-spheric forcing show some improvements as compared with that of the NCEP GFS.

  17. Sea surface wind perturbations over the Kashevarov Bank of the Okhotsk Sea: a satellite study

    Directory of Open Access Journals (Sweden)

    T. I. Tarkhova

    2011-02-01

    Full Text Available Sea surface wind perturbations over sea surface temperature (SST cold anomalies over the Kashevarov Bank (KB of the Okhotsk Sea are analyzed using satellite (AMSR-E and QuikSCAT data during the summer-autumn period of 2006–2009. It is shown, that frequency of cases of wind speed decreasing over a cold spot in August–September reaches up to 67%. In the cold spot center SST cold anomalies reached 10.5 °C and wind speed lowered down to ~7 m s−1 relative its value on the periphery. The wind difference between a periphery and a centre of the cold spot is proportional to SST difference with the correlations 0.5 for daily satellite passes data, 0.66 for 3-day mean data and 0.9 for monthly ones. For all types of data the coefficient of proportionality consists of ~0.3 m s−1 on 1 °C.

  18. SAT-WIND project. Final report[Winds from satellites for offshore and coastal wind energy mapping and wind-indexing

    Energy Technology Data Exchange (ETDEWEB)

    Hasager, C.B.; Astrup, P.; Nielsen, M. (and others)

    2007-04-15

    The SAT-WIND project 'Winds from satellites for offshore and coastal wind energy mapping and wind-indexing' was a research project funded by STVF/DSF in the years 2003 to 2006 (Sagsnr. 2058-03-0006). The goal of the project was to verify the applicability of satellite wind maps derived from passive microwave, altimeter, scatterometer and imaging Synthetic Aperture Radar (SAR) technologies for wind energy tools for wind resources and wind-indexing. The study area was the Danish Seas including the North Sea, interior seas and the Baltic Sea. The report describes technical details on the satellite data sources including: 1) passive microwave (SSM/I, AMSR-E), 2) passive microwave polarimetric (WindSat), 3) scatterometer (ERS, QuikSCAT, Midori-2 and NSCAT), 4) altimeter (ERS, Topex, Poseidon, GFO-1, Jason-1), 5) SAR (ERS, Envisat). The SAR wind maps were treated in S-WAsP developed by Risoe National Laboratory in cooperation with GRAS A/S in the innovative project SAT-WIND-SMV (Sagsnr. 2104-05-0084) in the years 2005 and 2006 in parallel with SAT-WIND. The results from the SAT-WIND project are presented. These include ocean wind statistics, offshore wind resource estimates and comparison results for wind-indexing. (au)

  19. ARCTIC SEA ICE FORECASTING EXPERIMENTS IN THE SUMMER OF 2010%2010年夏季北极海冰数值预报试验

    Institute of Scientific and Technical Information of China (English)

    杨清华; 李春花; 邢建勇; 李群; 张林; 李明

    2012-01-01

    为保障中国第四次北极科学考察的顺利开展,于2010年6-8月开展了北极海冰预报预测服务.预报试验基于MITgcm(麻省理工学院通用环流模式),以NCEP GFS(美国国家环境预测中心全球预报系统)资料为大气强迫,初始化分别使用美国冰雪中心SSM/I(专用微波成像仪)或德国不莱梅大学AMSR-E(地球观测系统先进微波扫描辐射计)北极海冰密集度卫星资料.对2010年6-8月数值预报结果的初步评估表明,预报结果同卫星观测资料比较一致.在发生快速海冰变化的太平洋扇区,预报结果优于惯性预报,表明模式具有较好的局地海冰数值预报能力.%In an effort to support the Chinese Arctic Research Expedition in the summer of 2010, the Arctic sea ice numerical forecasting experiments were conducted. A regional Arctic configuration of the Massachusetts Institute of Technology general circulation model ( MITgcm) was chosen as the coupled ice-ocean model for forecasting sea ice conditions in the Arctic Ocean. The numerical weather prediction of the National Center for Environmental Prediction Global Forecast System (NCEP GFS) was chosen as the atmospheric forcing, and two different satellite-derived sea ice concentration products were tested as initialization: (1) the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) and (2) the Special Sensor Microwave Imager (SSM/I) . Forecast skill assessments of the sea ice concentration fields from these numerical experiments are presented.

  20. Comparison of chlorophyll products derived from MODIS-Aqua and modification of operational algorithms in the South China Sea%南海海域MODIS-Aqua叶绿素浓度产品的精度对比和区域性算法修正

    Institute of Scientific and Technical Information of China (English)

    赵文静; 曹文熙; 王桂芬; 胡水波; 林俊芳; 许占堂

    2014-01-01

    利用2004~2012年在南海获得的9个航次的实测Chl-a数据,采用NASA标准业务化算法OC3和针对低Chl-a水体所发展的最新算法OCI反演获得了相应的MODIS-Aqua Chl-a产品.通过建立实测与遥感产品的时空匹配数据对,开展了Chl-a产品的适用性评估,并对比分析了上述两种算法的性能.在此基础上,利用南海实测遥感反射率(Rrs(λ))和MODIS-AquaRrs(λ)产品以及相应实测Chl-a的匹配数据集,分别对算法OC3和OCI进行了区域性修正.结果显示:基于算法OC3和OCI反演所得的MODIS-Aqua Chl-a产品值均高估了实测值,平均绝对误差(APD)的精度分别为56.30%和42.58%,且算法OCI可明显改善低Chl-a水体(<0.25 mg· m-3)的反演精度;采用南海MODIS-AquaRrs(λ)产品与实测Chl-a匹配数据集(N=82)修正后的区域性算法NOC3和NOCI的精度均有不同程度提高,APD精度分别为37.85%和36.74%;采用现场实测Rrs(λ)与Chl-a匹配数据集(N=123)进行区域性修正后的算法INOC3和INOCI的APD精度分别为36.61%和37.79%,上述两种方案精度较为接近.因此,对于南海海域而言,算法的区域性修正对于改善MODIS-Aqua Chl-a产品精度非常重要.

  1. PSR based soil moisture estimates in high vegetation and topographic domain

    Science.gov (United States)

    Bindlish, R.; Jackson, T. J.; Gasiewski, A. J.; Stankov, B. B.; Cosh, M. H.; Mladenova, I.

    2006-05-01

    One of the objectives of the Soil Moisture Experiments 2004 (SMEX04) was to understand the role of the land surface in the North American Monsoon System. Other goals included addressing the effect of spatial variability introduced by topography and vegetation on convective precipitation. SMEX04 was conducted over two regions: Arizona - semi-arid climate with sparse vegetation and moderate topography, and Sonora (Mexico) - moderate vegetation with strong topographic gradients. Each mapping domain is about 75 km x 50 km, providing an excellent area for calibration and validation of AMSR-E observations. The Polarimetric Scanning Radiometer (PSR/CX) was flown on a Naval Research Lab P- 3B aircraft as part of SMEX04 (10 dates of coverage over Arizona and 11 over Sonora). The primary objectives of PSR/CX during SMEX04 addressed in this study are: 1) Calibration and validation of AMSR observations over different parts of the globe and to check for the presence of RFI, and 2) development of soil moisture estimates using C-band imagery in diverse landscapes (topographic and vegetation regimes). The Arizona domain has a significant amount of exposed rock content. The presence of rocks results in high brightness temperature observations and the effect of rock fraction has to be addressed in the soil moisture retrievals. PSR/CX observations provide microwave observations at high resolution over a large scale sampling domain. The PSR/CX observations agree with the general meteorological conditions. The PSR estimated soil moisture compared well with the ground observations made over both the domains. The convective precipitation events result in interesting soil moisture pattern over the SMEX04 domain. These soil moisture estimates are critical to study the effect of soil moisture in hydrologic and climate modeling.

  2. Comparative Perspectives on Recent Trends in Land Surface Dynamics in the Grasslands of North and South America

    Science.gov (United States)

    Henebry, G. M.; Valle De Carvalho E Oliveira, P.; Zheng, B.; de Beurs, K.; Owsley, B.

    2015-12-01

    In our current era of intensive earth observation the time is ripe to shift away from studies relying on single sensors or single products to the synergistic use of multiple sensors and products at complementary spatial, temporal, and spectral scales. The use of multiple time series can not only reveal hotspots of change in land surface dynamics, but can indicate plausible proximate causes of the changes and suggest their possible consequences. Here we explore recent trends in the land surface dynamics of exemplary semi-arid grasslands in the western hemisphere, including the shortgrass prairie of eastern Colorado and New Mexico, the sandhills prairie of Nebraska, the "savana gramineo-lenhosa" variety of cerrado in central Brazil, and the pampas of Argentina. Observational datasets include (1) NBAR-based vegetation indices, land surface temperature, and evapotranspiration from MODIS, (2) air temperature, water vapor, and vegetation optical depth from AMSR-E and AMSR2, (3) surface air temperature, water vapor, and relative humidity from AIRS, and (4) surface shortwave, longwave, and total net flux from CERES. The spatial resolutions of these nested data include 500 m, 1000 m, 0.05 degree, 25 km, and 1 degree. We apply the nonparametric Seasonal Kendall trend test to each time series independently to identify areas of significant change. We then examine polygons of co-occurrence of significant change in two or more types of products using the surface radiation and energy budgets as guides to interpret the multiple changes. Changes occurring across broad areas are more likely to be of climatic origin; whereas, changes that are abrupt in space and time and of limited area are more likely anthropogenic. Results illustrate the utility of considering multiple remote sensing products as complementary views of land surface dynamics.

  3. Monitoring and Characterizing Seasonal Drought, Water Supply Pattern and Their Impact on Vegetation Growth Using Satellite Soil Moisture Data, GRACE Water Storage and In-situ Observations.

    Science.gov (United States)

    A, G.; Velicogna, I.; Kimball, J. S.; Kim, Y.; Colliander, A.; Njoku, E. G.

    2015-12-01

    We combine soil moisture (SM) data from AMSR-E, AMSR-2 and SMAP, terrestrial water storage (TWS) changes from GRACE, in-situ groundwater measurements and atmospheric moisture data to delineate and characterize the evolution of drought and its impact on vegetation growth. GRACE TWS provides spatially continuous observations of total terrestrial water storage changes and regional drought extent, persistence and severity, while satellite derived soil moisture estimates provide enhanced delineation of plant-available soil moisture. Together these data provide complementary metrics quantifying available plant water supply. We use these data to investigate the supply changes from water components at different depth in relation to satellite based vegetation metrics, including vegetation greenness (NDVI) measures from MODIS and related higher order productivity (GPP) before, during and following the major drought events observed in the continental US for the past 14 years. We observe consistent trends and significant correlations between monthly time series of TWS, SM, NDVI and GPP. We study how changes in atmosphere moisture stress and coupling of water storage components at different depth impact on the spatial and temporal correlation between TWS, SM and vegetation metrics. In Texas, we find that surface SM and GRACE TWS agree with each other in general, and both capture the underlying water supply constraints to vegetation growth. Triggered by a transit increase in precipitation following the 2011 hydrological drought, vegetation productivity in Texas shows more sensitivity to surface SM than TWS. In the Great Plains, the correspondence between TWS and vegetation productivity is modulated by temperature-induced atmosphere moisture stress and by the coupling between surface soil moisture and groundwater through irrigation.

  4. Snowmelt and Surface Freeze/Thaw Timings over Alaska derived from Passive Microwave Observations using a Wavelet Classifier

    Science.gov (United States)

    Steiner, N.; McDonald, K. C.; Dinardo, S. J.; Miller, C. E.

    2015-12-01

    Arctic permafrost soils contain a vast amount of organic carbon that will be released into the atmosphere as carbon dioxide or methane when thawed. Surface to air greenhouse gas fluxes are largely dependent on such surface controls as the frozen/thawed state of the snow and soil. Satellite remote sensing is an important means to create continuous mapping of surface properties. Advances in the ability to determine soil and snow freeze/thaw timings from microwave frequency observations improves upon our ability to predict the response of carbon gas emission to warming through synthesis with in-situ observation, such as the 2012-2015 Carbon in Arctic Reservoir Vulnerability Experiment (CARVE). Surface freeze/thaw or snowmelt timings are often derived using a constant or spatially/temporally variable threshold applied to time-series observations. Alternately, time-series singularity classifiers aim to detect discontinuous changes, or "edges", in time-series data similar to those that occur from the large contrast in dielectric constant during the freezing or thaw of soil or snow. We use multi-scale analysis of continuous wavelet transform spectral gradient brightness temperatures from various channel combinations of passive microwave radiometers, Advanced Microwave Scanning Radiometer (AMSR-E, AMSR2) and Special Sensor Microwave Imager (SSM/I F17) gridded at a 10 km posting with resolution proportional to the observational footprint. Channel combinations presented here aim to illustrate and differentiate timings of "edges" from transitions in surface water related to various landscape components (e.g. snow-melt, soil-thaw). To support an understanding of the physical basis of observed "edges" we compare satellite measurements with simple radiative transfer microwave-emission modeling of the snow, soil and vegetation using in-situ observations from the SNOw TELemetry (SNOTEL) automated weather stations. Results of freeze/thaw and snow-melt timings and trends are

  5. Two different zinc(II)-aqua complexes held up by a metal-oxide based support: Synthesis, crystal structure and catalytic activity of [HMTAH]2[{Zn(H2O)5}{Zn(H2O)4}{Mo7O24}].2H2O (HMTAH = protonated hexamethylenetetramine)

    Indian Academy of Sciences (India)

    T Arumuganathan; A Srinivasarao; T Vijay Kumar; Samar K Das

    2008-01-01

    An inorganic−organic hybrid material, [HMTAH]2[{Zn(H2O)5}{Zn(H2O)4}{Mo7O24}].2H2O (1) (where HMTAH = protonated hxamethylenetetramine) has been synthesized and structurally characterized. The compound 1 crystallizes in a monoclinic space group 2/. The crystal data of 1: = 43.12(3), = 12.399(10), = 16.285(13), = 111.131(11), = 8. Its crystal structure shows that two different Zn(II)-aqua complexes, [Zn(H2O)5]2+ and [Zn(H2O)4]2+ are covalently coordinated to a heptamolybdateanion [Mo7O24]6- resulting in an anionic species of polyoxometalate supported zinc-aqua complexes, [{Zn(H2O)}{Zn(H2O)4}{Mo7O24}]2-, that is stabilized with two protonated hexamethylenetetramine cations in the title compound 1. In the crystal structure, both lattice water molecules are found to interact with the heptamolybdate cluster anion and the protonated hexamethylenetetramine cation resulting in an intricate three-dimensional hydrogen bonding network. Interestingly, compound 1 exhibits catalytic activity towards oxidation of some primary alcohols.

  6. A Quasi-Global Approach to Improve Day-Time Satellite Surface Soil Moisture Anomalies through the Land Surface Temperature Input

    Directory of Open Access Journals (Sweden)

    Robert M. Parinussa

    2016-10-01

    Full Text Available Passive microwave observations from various spaceborne sensors have been linked to the soil moisture of the Earth’s surface layer. A new generation of passive microwave sensors are dedicated to retrieving this variable and make observations in the single theoretically optimal L-band frequency (1–2 GHz. Previous generations of passive microwave sensors made observations in a range of higher frequencies, allowing for simultaneous estimation of additional variables required for solving the radiative transfer equation. One of these additional variables is land surface temperature, which plays a unique role in the radiative transfer equation and has an influence on the final quality of retrieved soil moisture anomalies. This study presents an optimization procedure for soil moisture retrievals through a quasi-global precipitation-based verification technique, the so-called Rvalue metric. Various land surface temperature scenarios were evaluated in which biases were added to an existing linear regression, specifically focusing on improving the skills to capture the temporal variability of soil moisture. We focus on the relative quality of the day-time (01:30 pm observations from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E, as these are theoretically most challenging due to the thermal equilibrium theory, and existing studies indicate that larger improvements are possible for these observations compared to their night-time (01:30 am equivalent. Soil moisture data used in this study were retrieved through the Land Parameter Retrieval Model (LPRM, and in line with theory, both satellite paths show a unique and distinct degradation as a function of vegetation density. Both the ascending (01:30 pm and descending (01:30 am paths of the publicly available and widely used AMSR-E LPRM soil moisture products were used for benchmarking purposes. Several scenarios were employed in which the land surface temperature input for

  7. OW NASA MODIS Aqua Ocean Color

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains satellite-derived sea-surface ocean color (chlorophyll-a) measurements collected by means of the Moderate Resolution Imaging Spectroradiometer...

  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. 基于MODIS/Aqua的胶州湾及青岛近海叶绿素a浓度年变化特征分析%Analysis on the Annual Change Characteristics of Chlorophyll-a Concentration in the Jiaozhou Bay and Qingdao Coastal Area Based on MODIS/Aqua

    Institute of Scientific and Technical Information of China (English)

    刘晓燕; 杨倩; 周燕

    2015-01-01

    利用2002-2013年MODIS/Aqua的Level 1B数据,经标准大气校正算法和叶绿素a浓度[chl-a]波段比经验算法(OC2M-HI),获得近12 a的胶州湾及青岛近海海域晴空的MOIDS/Aqua叶绿素a浓度.根据GOCI/COMS和MODIS/Aqua叶绿素a浓度产品在胶州湾及青岛近海交叉比较的结果[1],对2002-2013年的MODIS/Aqua [chl-a]进行了修正.基于修正后的MODIS/Aqua[chl-a]分析了胶州湾及青岛近海的叶绿素a浓度年变化特征.该海域的叶绿素a浓度大致呈现北高南低,湾内高于近海的特点,且每年空间分布趋势基本一致;近12a的[chl-a]呈小的上升趋势,胶州湾的上升趋势大于青岛近海.胶州湾跨海大桥建设前,其附近区域叶绿素a浓度以0.47 μg/L/year的趋势上升,基值为2.62μg/L;大桥开建及通车后,其附近叶绿素a浓度年变化趋势不明显,但基值明显增大(4.00 μg/L).

  10. Prediction of high spatio-temporal resolution land surface temperature under cloudy conditions using microwave vegetation index and ANN

    Science.gov (United States)

    Shwetha, H. R.; Kumar, D. Nagesh

    2016-07-01

    Land Surface Temperature (LST) with high spatio-temporal resolution is in demand for hydrology, climate change, ecology, urban climate and environmental studies, etc. Moderate Resolution Imaging Spectroradiometer (MODIS) is one of the most commonly used sensors owing to its high spatial and temporal availability over the globe, but is incapable of providing LST data under cloudy conditions, resulting in gaps in the data. In contrast, microwave measurements have a capability to penetrate under clouds. The current study proposes a methodology by exploring this property to predict high spatio-temporal resolution LST under cloudy conditions during daytime and nighttime without employing in-situ LST measurements. To achieve this, Artificial Neural Networks (ANNs) based models are employed for different land cover classes, utilizing Microwave Polarization Difference Index (MPDI) at finer resolution with ancillary data. MPDI was derived using resampled (from 0.25° to 1 km) brightness temperatures (Tb) at 36.5 GHz channel of dual polarization from Advance Microwave Scanning Radiometer (AMSR)-Earth Observing System and AMSR2 sensors. The proposed methodology is tested over Cauvery basin in India and the performance of the model is quantitatively evaluated through performance measures such as correlation coefficient (r), Nash Sutcliffe Efficiency (NSE) and Root Mean Square Error (RMSE). Results revealed that during daytime, AMSR-E(AMSR2) derived LST under clear sky conditions corresponds well with MODIS LST resulting in values of r ranging from 0.76(0.78) to 0.90(0.96), RMSE from 1.76(1.86) K to 4.34(4.00) K and NSE from 0.58(0.61) to 0.81(0.90) for different land cover classes. During nighttime, r values ranged from 0.76(0.56) to 0.87(0.90), RMSE from 1.71(1.70) K to 2.43(2.12) K and NSE from 0.43(0.28) to 0.80(0.81) for different land cover classes. RMSE values found between predicted LST and MODIS LST during daytime under clear sky conditions were within acceptable

  11. Application of GSMaP and MODIS/SeaWiFS Downward Surface Short Wave Radiation in the Land Simulation System: Yesterday's Earth at EORC (YEE)

    Science.gov (United States)

    Oki, T.; Kachi, M.; Kubota, T.; Fujii, H.; Murakami, H.

    2010-12-01

    -MODIS). Results were compared to in-situ data in daily and monthly basis. They were also compared to retrievals of them by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E). In most of validation sites, satellite-based SWR data shows better agreement with in-situ measurement compared to that from JRA-25. Generally, output parameters from YEE-MODIS show better agreement with in-situ data and AMSR-E retrievals, except for snow depth in snowmelt season. Snow depths calculated by YEE-JRA25 and YEE-GSMaP show good correspondence to in-situ measurement for seasonal cycle. Results of YEE-MODIS and YEE-JRA25 are similar during mid-winter, however, YEE-MODIS overestimates during snow melt season. In future, we plan to replace fixed database such as Normalized Difference Vegetation Index (NDVI), and assimilation of forecast parameters such as soil moisture or snow depth are also discussed to improve YEE.

  12. Variations in the Sea Ice Edge and the Marginal Ice Zone on Different Spatial Scales as Observed from Different Satellite Sensor

    Science.gov (United States)

    Markus, Thorsten; Henrichs, John

    2006-01-01

    The Marginal sea Ice Zone (MIZ) and the sea ice edge are the most dynamic areas of the sea ice cover. Knowledge of the sea ice edge location is vital for routing shipping in the polar regions. The ice edge is the location of recurrent pla