WorldWideScience

Sample records for satellite wind products

  1. NORSEWInD satellite wind climatology

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Mouche, Alexis

    is to provide new offshore wind climatology map for the entire area of interest based on satellite remote sensing. This has been based on Synthetic Aperture Radar (SAR) from Envisat ASAR using 9000 scenes re-processed with ECMWF wind direction and CMOD-IFR. The number of overlapping samples range from 450....... QuikSCAT ocean wind vector observations have been analysed for the same four parameters and ASCAT for mean wind speed. All satellite data has been compared to in-situ observations available in the Norsewind project. SSM/I passive microwave wind speed data from 24 years observed around 6 times per day...... are used to estimate trends in offshore winds and interestingly a shift in the seasonal pattern is notice. All satellite-based wind products are valid at 10 m, thus it is desirable to lift winds to higher levels for wind energy products. A method has been suggested to lift winds from 10 m to hub...

  2. Bringing satellite winds to hub-height

    DEFF Research Database (Denmark)

    Badger, Merete; Pena Diaz, Alfredo; Bredesen, Rolv Erlend

    2012-01-01

    Satellite observations of the ocean surface can provide detailed information about the spatial wind variability over large areas. This is very valuable for the mapping of wind resources offshore where other measurements are costly and sparse. Satellite sensors operating at microwave frequencies...... measure the amount of radar backscatter from the sea surface, which is a function of the instant wind speed, wind direction, and satellite viewing geometry. A major limitation related to wind retrievals from satellite observations is that existing empirical model functions relate the radar backscatter...

  3. Satellite Remote Sensing in Offshore Wind Energy

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Astrup, Poul

    2013-01-01

    Satellite remote sensing of ocean surface winds are presented with focus on wind energy applications. The history on operational and research-based satellite ocean wind mapping is briefly described for passive microwave, scatterometer and synthetic aperture radar (SAR). Currently 6 GW installed...

  4. Extrapolating Satellite Winds to Turbine Operating Heights

    DEFF Research Database (Denmark)

    Badger, Merete; Pena Diaz, Alfredo; Hahmann, Andrea N.;

    2016-01-01

    Ocean wind retrievals from satellite sensors are typically performed for the standard level of 10 m. This restricts their full exploitation for wind energy planning, which requires wind information at much higher levels where wind turbines operate. A new method is presented for the vertical extra...

  5. Wind Statistics Offshore based on Satellite Images

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Mouche, Alexis; Badger, Merete

    2009-01-01

    Ocean wind maps from satellites are routinely processed both at Risø DTU and CLS based on the European Space Agency Envisat ASAR data. At Risø the a priori wind direction is taken from the atmospheric model NOGAPS (Navel Operational Global Atmospheric Prediction System) provided by the U.S. Navy......’s Master Environmental Library. At CLS the a priori wind direction is taken from the ECMWF (European Centre of Medium-range Weather Forecasting). It is also possible to use other sources of wind direction e.g. the satellite-based ASCAT wind directions as demonstrated by CLS. The wind direction has to known...

  6. Bringing satellite winds to hub-height

    DEFF Research Database (Denmark)

    Badger, Merete; Pena Diaz, Alfredo; Bredesen, Rolv Erlend

    2012-01-01

    Satellite observations of the ocean surface can provide detailed information about the spatial wind variability over large areas. This is very valuable for the mapping of wind resources offshore where other measurements are costly and sparse. Satellite sensors operating at microwave frequencies m...

  7. Offshore winds mapped from satellite remote sensing

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay

    2014-01-01

    the uncertainty on the model results on the offshore wind resource, it is necessary to compare model results with observations. Observations from ground-based wind lidar and satellite remote sensing are the two main technologies that can provide new types of offshore wind data at relatively low cost....... The advantages of microwave satellite remote sensing are 1) horizontal spatial coverage, 2) long data archives and 3) high spatial detail both in the coastal zone and of far-field wind farm wake. Passive microwave ocean wind speed data are available since 1987 with up to 6 observations per day with near...

  8. Comparisons of Monthly Mean 10 M Wind Speeds from Satellites and NWP Products Over the Global Ocean

    Science.gov (United States)

    2009-10-09

    Resolution QSCAT SSM/I NOGAPS ERA-40 NCEP Sea Winds instrument on the Quick Scatterometer Special Sensor Microwave/Imager Navy Operational...measurements with 25-point smoothing as described earlier. [25] Within the latitudes spanning the Arctic and Antarctic , no ice mask is applied in order to...ET AL.: 10 M WINDS OVER THE GLOBAL OCEAN D16109 egies that blend two or more of these products to produce improved forcing fields. [53

  9. Wind farm production estimates

    DEFF Research Database (Denmark)

    Larsen, Torben J.; Larsen, Gunner Chr.; Aagaard Madsen, Helge;

    2012-01-01

    on a 3GHz pc. The turbine controller is fully implemented. Initially, production estimates of a single turbine under free and wake conditions, respectively, are compared for (undis- turbed) mean wind speeds ranging from 3m/s to 25m/s. The undisturbed situation refers to a wind direction bin defined......In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind...... as 270◦ ±5◦, whereas the wake situation refers to the wind direction bin 319◦ ±5◦. In the latter case, the investigated turbine operated in the wake of 6 upstream turbines, with the mean wind direction being equal to the orientation of the wind turbine row. The production of the entire wind farm has been...

  10. Satellite information for wind energy applications

    DEFF Research Database (Denmark)

    Nielsen, M.; Astrup, Poul; Hasager, Charlotte Bay

    2004-01-01

    wind data from several types of satellite observations. The RWT software allows an optimal calculation ofSAR wind resource statistics. A tab-file with SAR-based observed wind climate (OWC) data can be obtained for 10 m above sea level and used in WASP. RWT uses a footprint averaging technique to obtain...... an aid to map larger regions within shorter time. Field site observations of obstacles and hedges are still necessary. The raster-based map information from DEMand land cover maps can be converted for use in WASP. For offshore locations it is possible to estimate the wind resources based on ocean surface...

  11. Satellite information for wind energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, M.; Astrup, P.; Bay Hasager, C.

    2004-11-01

    An introduction to satellite information relevant for wind energy applications is given. It includes digital elevation model (DEM) data based on satellite observations. The Shuttle Radar Topography Mission (SRTM) is useful for regional scale wind resource studies. Comparison results from complex terrain in Spain and flat terrain in Denmark are found to be acceptable for both sites. Also land cover type information can be retrieved from satellite observations. Land cover type maps have to be combined with roughness data from field observation or literature values. Land cover type maps constitute an aid to map larger regions within shorter time. Field site observations of obstacles and hedges are still necessary. The raster-based map information from DEM and land cover maps can be converted for use in WASP. For offshore locations it is possible to estimate the wind resources based on ocean surface wind data from several types of satellite observations. The RWT software allows an optimal calculation of SAR wind resource statistics. A tab-file with SAR-based observed wind climate (OWC) data can be obtained for 10 m above sea level and used in WASP. RWT uses a footprint averaging technique to obtain data as similar as possible to mast observations. Maximum-likelihood fitting is used to calculate the Weibull A and k parameters from the constrained data set. Satellite SAR wind maps cover the coastal zone from 3 km and offshore with very detailed information of 400 m by 400 m grid resolution. Spatial trends in mean wind, energy density, Weibull A and k and uncertainty values are provided for the area of interest. Satellite scatterometer wind observations have a spatial resolution of 25 km by 25 km. These data typically represent a site further offshore, and the tab-file statistics should be used in WASP combined with topography and roughness information to assess the coastal wind power potential. Scatterometer wind data are observed {approx} twice per day, whereas SAR only

  12. Wind Atlas of Bay of Bengal with Satellite Wind Measurement

    DEFF Research Database (Denmark)

    Nadi, Navila Rahman

    The objective of this study is to obtain appropriate offshore location in the Bay of Bengal, Bangladesh for further development of wind energy. Through analyzing the previous published works, no offshore wind energy estimation has been found here. That is why, this study can be claimed as the first...... footstep towards offshore wind energy analysis for this region. Generally, it is difficult to find offshore wind data relative to the wind turbine hub heights, therefore a starting point is necessary to identify the possible wind power density of the region. In such scenario, Synthetic aperture radars (SAR......) have proven useful. In this study, SAR based dataset- ENVISAT ASAR has been used for Wind Atlas generation. Furthermore, a comparative study has been performed with Global Wind Atlas (GWA) to determine a potential offshore wind farm. Additionally, the annual energy production of that offshore windfarm...

  13. NODC Standard Product: World Ocean Circulation Program (WOCE) Global Data, Version 2: Satellite sea surface winds data on CD-ROM (NODC Accession 0000318)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface wind and other data were collected using microwave scatterometers satellite in a world-wide distribution from May 5, 1991 to May 31, 2000. Data were...

  14. Wind farm production estimates

    DEFF Research Database (Denmark)

    Larsen, Torben J.; Larsen, Gunner Chr.; Aagaard Madsen, Helge

    2012-01-01

    In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind the DWMm......In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind...... on a 3GHz pc. The turbine controller is fully implemented. Initially, production estimates of a single turbine under free and wake conditions, respectively, are compared for (undis- turbed) mean wind speeds ranging from 3m/s to 25m/s. The undisturbed situation refers to a wind direction bin defined...... as 270◦ ±5◦, whereas the wake situation refers to the wind direction bin 319◦ ±5◦. In the latter case, the investigated turbine operated in the wake of 6 upstream turbines, with the mean wind direction being equal to the orientation of the wind turbine row. The production of the entire wind farm has been...

  15. Lessons Learned from the Deployment and Integration of a Microwave Sounder Based Tropical Cyclone Intensity and Surface Wind Estimation Algorithm into NOAA/NESDIS Satellite Product Operations

    Science.gov (United States)

    Longmore, S. P.; Knaff, J. A.; Schumacher, A.; Dostalek, J.; DeMaria, R.; Chirokova, G.; Demaria, M.; Powell, D. C.; Sigmund, A.; Yu, W.

    2014-12-01

    The Colorado State University (CSU) Cooperative Institute for Research in the Atmosphere (CIRA) has recently deployed a tropical cyclone (TC) intensity and surface wind radii estimation algorithm that utilizes Suomi National Polar-orbiting Partnership (S-NPP) satellite Advanced Technology Microwave Sounder (ATMS) and Advanced Microwave Sounding Unit (AMSU) from the NOAA18, NOAA19 and METOPA polar orbiting satellites for testing, integration and operations for the Product System Development and Implementation (PSDI) projects at NOAA's National Environmental Satellite, Data, and Information Service (NESDIS). This presentation discusses the evolution of the CIRA NPP/AMSU TC algorithms internally at CIRA and its migration and integration into the NOAA Data Exploitation (NDE) development and testing frameworks. The discussion will focus on 1) the development cycle of internal NPP/AMSU TC algorithms components by scientists and software engineers, 2) the exchange of these components into the NPP/AMSU TC software systems using the subversion version control system and other exchange methods, 3) testing, debugging and integration of the NPP/AMSU TC systems both at CIRA/NESDIS and 4) the update cycle of new releases through continuous integration. Lastly, a discussion of the methods that were effective and those that need revision will be detailed for the next iteration of the NPP/AMSU TC system.

  16. Insuring wind energy production

    Science.gov (United States)

    D'Amico, Guglielmo; Petroni, Filippo; Prattico, Flavio

    2017-02-01

    This paper presents an insurance contract that the supplier of wind energy may subscribe in order to immunize the production of electricity against the volatility of the wind speed process. The other party of the contract may be any dispatchable energy producer, like gas turbine or hydroelectric generator, which can supply the required energy in case of little or no wind. The adoption of a stochastic wind speed model allows the computation of the fair premium that the wind power supplier has to pay in order to hedge the risk of inadequate output of electricity at any time. Recursive type equations are obtained for the prospective mathematical reserves of the insurance contract and for their higher order moments. The model and the validity of the results are illustrated through a numerical example.

  17. Comparing satellite SAR and wind farm wake models

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Vincent, P.; Husson, R.

    2015-01-01

    The aim of the paper is to present offshore wind farm wake observed from satellite Synthetic Aperture Radar (SAR) wind fields from RADARSAT-1/-2 and Envisat and to compare these wakes qualitatively to wind farm wake model results. From some satellite SAR wind maps very long wakes are observed. Th...

  18. Quantifying offshore wind resources from satellite wind maps: Study area the North Sea

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Barthelmie, Rebecca Jane; Christiansen, Merete B.;

    2006-01-01

    Offshore wind resources are quantified from satellite synthetic aperture radar (SAR) and satellite scatterometer observations at local and regional scale respectively at the Horns Rev site in Denmark. The method for wind resource estimation from satellite observations interfaces with the wind atl...

  19. Offshore winds from a new generation of European satellites

    DEFF Research Database (Denmark)

    Badger, Merete; Karagali, Ioanna; Ahsbahs, Tobias Torben

    Offshore wind fields retrieved from satellite Synthetic Aperture Radar (SAR) observations can give valuable insight in the spatial wind variability over large areas. We can utilize this for mapping of wind farm wakes, wind resources, coastal wind speed gradients, storms, and other wind phenomena...... satellites and services could lower these barriers for applications in wind energy significantly. The Sentinel-1 A/B missions by the European Space Agency (ESA) deliver C-band SAR observations at an unprecedented coverage and spatial resolution. Over the seas of Europe, approximately 200 new acquisitions...... take place every day. DTU Wind Energy operates a system for processing of the raw SAR data to wind fields in near-real-time. The wind fields are available for download; for example by users in the wind energy community. Comparisons with mast and lidar observations have shown RMS errors of 1.3-1.5 m...

  20. Satellite based wind resource assessment over the South China Sea

    DEFF Research Database (Denmark)

    Badger, Merete; Astrup, Poul; Hasager, Charlotte Bay

    2014-01-01

    modeling to develop procedures and best practices for satellite based wind resource assessment offshore. All existing satellite images from the Envisat Advanced SAR sensor by the European Space Agency (2002-12) have been collected over a domain in the South China Sea. Wind speed is first retrieved from...

  1. The CMEMS L3 scatterometer wind product

    Science.gov (United States)

    de Kloe, Jos; Stoffelen, Ad; Verhoef, Anton

    2017-04-01

    Within the Copernicus Marine Environment Monitoring Service KNMI produces several ocean surface Level 3 wind products. These are daily updated global maps on a regular grid of the available scatterometer wind observations and derived properties, and produced from our EUMETSAT Ocean and Sea Ice Satellite Application Facility (OSI SAF) operational near-real time (NRT) Level 2 swath-based wind products by linear interpolation. Currently available products are the ASCAT on Metop A/B stress equivalent wind vectors, accompanied by ECMWF NWP reference stress equivalent winds from the operational ECMWF NWP model. For each ASCAT scatterometer we provide products on 2 different resolutions, 0.25 and 0.125 degrees. In addition we provide wind stress vectors, and derivative fields (curl and divergence) for stress equivalent wind and wind stress, both for the observations and for the NWP reference winds. New NRT scatterometer products will be made available when additional scatterometer instruments become available, and NRT access to the data can be arranged. We hope OSCAT on the Indian ScatSat-1 satellite will be the the next NRT product to be added. In addition multi-year reprocessing datasets have been made available for ASCAT on Metop-A (1-Jan-2007 up to 31-Mar-2014) and Seawinds on QuikScat (19-Jul-1999 up to 21-Nov-2009). For ASCAT 0.25 and 0.125 degree resolution products are provided, and for QuikScat 0.50 and 0.25 degree resolution products are provided, These products are based on reprocessing the L2 scatterometer products with the latest processing software version, and include reference winds from the ECMWF ERA-Interim model. Additional reprocessing datasets will be added when reprocessed L2 datasets become available. This will hopefully include the ERS-1 and ERS-2 scatterometer datasets (1992-2001), which will extend the available date range back to 1992. These products are available for download through the CMEMS portal website: http://marine.copernicus.eu/

  2. Satellite Constellation for Ocean Wind and Stress

    Science.gov (United States)

    Liu, W.; Xie, X.

    2009-12-01

    A scatterometer sends microwave pulses to the earth's surface and measure the power backscattered from the surface roughness. The roughness is believed to be in equilibrium with the stress (turbulent transport of momentum). The backscatter depends not only on the magnitude of the stress but also the stress direction relative to the direction of the radar beam. Measuring both stress magnitude and direction is the major unique capability of the scatterometer. Although stress drives ocean circulation, we do not have any large-scale stress measurement except from the scatterometer; our concept of stress distribution is largely derived from our knowledge on wind. Stress is closely related to wind. The geophysical product of the scatterometer is the equivalent neutral wind. It is a fictitious quantity, which has an unambiguous relation with surface stress by definition, while the relation between actual wind and surface stress depends on atmospheric vertical density stratification. Over most of the ocean, the atmosphere is near neutral and the current is much smaller than wind and it is generally assumed that the equivalent neutral wind is the actual wind. QuikSCAT, a Ku-band scatterometer, was launched in 1999. The scientific contributions to natural disaster, energy, weather, climate, water, ecosystem, and agriculture from one decade of QuikSCAT measurements will be presented. A C-band scatterometer, ASCAT, was launched by European Space Agency in 2006. Ku-band scatterometers, similar in design with QuikSCAT, will be launched by India and China in 2010 and 2011. One polar orbiting scatterometer could only sample the earth at most two times a day. If the future scatterometers will produce similarly high quality data, the future constellation of scatterometers, with different overhead crossing time, will meet the six hourly revisit frequency required by the operational weather forecast community and the inertial frequency required by research oceanographers. The coverage

  3. Satellite SAR applied in offhore wind resource mapping: possibilities and limitations

    Science.gov (United States)

    Hasager, C. B.

    Satellite remote sensing of ocean wind fields from Synthetic Aperture Radar (SAR) observations is presented. The study is based on a series of more than 60 ERS-2 SAR satellite scenes from the Horns Rev in the North Sea. The wind climate from the coastline and 80 km offshore is mapped in detail with a resolution of 400 m by 400 m grid cells. Spatial variations in wind speed as a function of wind direction and fetch are observed and discussed. The satellite wind fields are compared to in-situ observations from a tall offshore meteorological mast at which wind speed at 4 levels are analysed. The mast is located 14 km offshore and the wind climate is observed continously since May 1999. For offshore wind resource mapping the SAR-based wind field maps can constitute an alternative to in-situ observations and a practical method is developed for applied use in WAsP (Wind Atlas Analysis and Application Program). The software is the de facto world standard tool used for prediction of wind climate and power production from wind turbines and wind farms. The possibilities and limitations on achieving offshore wind resource estimates using SAR-based wind fields in lieu of in-situ data are discussed. It includes a presentation of the footprint area-averaging techniques tailored for SAR-based wind field maps. Averaging techniques are relevant for the reduction of noise apparent in SAR wind speed maps. Acknowledgments: Danish Research Agency (SAT-WIND Sagsnr. 2058-03-0006) for funding, ESA (EO-1356, AO-153) for ERS-2 SAR scenes, and Elsam Engineering A/S for in-situ met-data.

  4. Wind-driven marine phytoplank blooms: Satellite observation and analysis

    Science.gov (United States)

    Tang, DanLing

    2016-07-01

    Algal bloom is defined as a rapid increase or accumulation in biomass in an aquatic system. It not only can increase the primary production but also could result in negative ecological consequence, e.g.,Harmful Algal Blooms (HABs). According to the classic theory for the formation of algal blooms "critical depth" and "eutrophication", oligotrophic sea area is usually difficult to form a large area of algal blooms, and actuallythe traditional observation is only sporadic capture to the existence of algal blooms.Taking full advantage of multiple data of satellite remote sensing , this study introduces "Wind-driven algal blooms in open oceans: observation and mechanisms" It explained except classic coastal Ekman transport, the wind through a variety of mechanisms affecting the formation of algal blooms. Proposed a conceptual model of "Strong wind -upwelling-nutrient-phytoplankton blooms" in Western South China Sea (SCS) to assess role of wind-induced advection transport in phytoplankton bloom formation. It illustrates the nutrient resources that support long-term offshore phytoplankton blooms in the western SCS; (2)Proposal of the theory that "typhoons cause vertical mixing, induce phytoplankton blooms", and quantify their important contribution to marine primary production; Proposal a new ecological index for typhoon. Proposed remote sensing inversion models. (3)Finding of the spatial and temporaldistributions pattern of harmful algal bloom (HAB)and species variations of HAB in the South Yellow Sea and East China Sea, and in the Pearl River estuary, and their oceanic dynamic mechanisms related with monsoon; The project developed new techniques and generated new knowledge, which significantly improved understanding of the formation mechanisms of algal blooms. The proposed "wind-pump" mechanism integrates theoretical system combined "ocean dynamics, development of algal blooms, and impact on primary production", which will benefit fisheries management. These

  5. Detection of wind wakes offshore from satellite SAR

    Science.gov (United States)

    Christiansen, M. B.; Hasager, C. B.

    A study is presented on the mapping of ocean wind fields for detection of wind wakes downstream of an offshore wind farm. The study is based on ERS-2 Synthetic Aperture Radar (SAR) scenes obtained in 2003 over Horns Reef in the North Sea. A large offshore wind farm (80 wind turbines) is located 14-20 km offshore of Denmark on this submerged reef. Meteorological observations are available from an offshore mast; wind speed is measured at four heights up to 62 m and wind direction is measured at 60 m. Maps of wind speed are generated from geophysical model functions (CMOD-4, CMOD-IFR2) with a resolution of 400 m by 400 m using wind direction obtained from in-situ measurements as model input. The wind maps display zones of reduced mean wind speed downstream of the wind farm compared to upwind conditions. The reduction is approximately 10 % immediately behind the wind farm and the wake effect is vanishing over distances in the order of 10 km downstream. This is consistent with wake model predictions. Satellite SAR provides a good estimate of the propagation of wind wakes. Information on how structures affect the local wind climate is useful for wind energy purposes, particularly for siting of future offshore wind farms.

  6. Comparison of Satellite-Derived Wind Measurements with Other Wind Measurement Sensors

    Science.gov (United States)

    Susko, Michael; Herman, Leroy

    1995-01-01

    The purpose of this paper is to compare the good data from the Jimsphere launches with the data from the satellite system. By comparing the wind speeds from the Fixed Pedestal System 16 (FPS-16) Radar/Jimsphere Wind System and NASA's 50-MHz Radar Wind Profiler, the validation of winds from Geostationary Operational Environmental Satellite 7 (GOES-7) is performed. This study provides an in situ data quality check for the GOES-7 satellite winds. Comparison was made of the flowfields in the troposphere and the lower stratosphere of case studies of pairs of Jimsphere balloon releases and Radar Wind Profiler winds during Space Shuttle launches. The mean and standard deviation of the zonal component statistics, the meridional component statistics, and the power spectral density curves show good agreement between the two wind sensors. The standard deviation of the u and v components for the STS-37 launch (consisting of five Jimsphere/Radar Wind Profiler data sets) was 1.92 and 1.67 m/s, respectively; for the STS-43 launch (there were six Jimsphere/Wind Profiler data sets) it was 1.39 and 1.44 m/s, respectively. The overall standard deviation was 1.66 m/s for the u component and 1.55 m/s tor the v component, and a standard deviation of 2.27 m/s tor the vector wind difference. The global comparison of satellite with Jimsphere balloon vector winds shows a standard deviation of 3.15 m/s for STS-43 and 4.37 m/s for STS-37. The overall standard deviation of the vector wind was 3.76 m/s, with a root-mean-square vector difference of 4.43 m/s. These data have demonstrated that this unique comparison of the Jimsphere and satellite winds provides excellent ground truth and a frame of reference during testing and validation of satellite data

  7. 622 Mbps High-speed satellite communication system for WINDS

    Science.gov (United States)

    Ogawa, Yasuo; Hashimoto, Yukio; Yoshimura, Naoko; Suzuki, Ryutaro; Gedney, Richard T.; Dollard, Mike

    2006-07-01

    WINDS is the experimental communications satellite currently under joint development by Japanese Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT). The high-speed satellite communication system is very effective for quick deployment of high-speed networks economically. The WINDS will realize ultra high-speed networking and demonstrate operability of satellite communication systems in high-speed internet. NICT is now developing high-speed satellite communication system for WINDS. High-speed TDMA burst modem with high performance TPC error correction is underdevelopment. Up to the DAC on the transmitter and from the ADC on the receiver, all modem functions are performed in the digital processing technology. Burst modem has been designed for a user data rate up to 1244 Mbps. NICT is developing the digital terminal as a user interface and a network controller for this earth station. High compatibility with the Internet will be provided.

  8. A Non-MLE Approach for Satellite Scatterometer Wind Vector Retrievals in Tropical Cyclones

    Directory of Open Access Journals (Sweden)

    Suleiman Alsweiss

    2014-05-01

    Full Text Available Satellite microwave scatterometers are the principal source of global synoptic-scale ocean vector wind (OVW measurements for a number of scientific and operational oceanic wind applications. However, for extreme wind events such as tropical cyclones, their performance is significantly degraded. This paper presents a novel OVW retrieval algorithm for tropical cyclones which improves the accuracy of scatterometer based ocean surface winds when compared to low-flying aircraft with in-situ and remotely sensed observations. Unlike the traditional maximum likelihood estimation (MLE wind vector retrieval technique, this new approach sequentially estimates scalar wind directions and wind speeds. A detailed description of the algorithm is provided along with results for ten QuikSCAT hurricane overpasses (from 2003–2008 to evaluate the performance of the new algorithm. Results are compared with independent surface wind analyses from the National Oceanic and Atmospheric Administration (NOAA Hurricane Research Division’s H*Wind surface analyses and with the corresponding SeaWinds Project’s L2B-12.5 km OVW products. They demonstrate that the proposed algorithm extends the SeaWinds capability to retrieve wind speeds beyond the current range of approximately 35 m/s (minimal hurricane category-1 with improved wind direction accuracy, making this new approach a potential candidate for current and future conically scanning scatterometer wind retrieval algorithms.

  9. Offshore Wind Energy: Wind and Sea Surface Temperature from Satellite Observations

    DEFF Research Database (Denmark)

    Karagali, Ioanna

    as the entire atmosphere above. Under conditions of light winds and strong solar insolation, warming of the upper oceanic layer may occur. In this PhD study, remote sensing from satellites is used to obtain information for the near-surface ocean wind and the sea surface temperature over the North Sea...

  10. Wind class sampling of satellite SAR imagery for offshore wind resource mapping

    DEFF Research Database (Denmark)

    Badger, Merete; Badger, Jake; Nielsen, Morten

    2010-01-01

    High-resolution wind fields retrieved from satellite synthetic aperture radar (SAR) imagery are combined for mapping of wind resources offshore where site measurements are costly and sparse. A new sampling strategy for the SAR scenes is introduced, based on a method for statistical-dynamical down......High-resolution wind fields retrieved from satellite synthetic aperture radar (SAR) imagery are combined for mapping of wind resources offshore where site measurements are costly and sparse. A new sampling strategy for the SAR scenes is introduced, based on a method for statistical......-dynamical downscaling of large-scale wind conditions using a set of wind classes that describe representative wind situations. One or more SAR scenes are then selected to represent each wind class and the classes are weighted according to their frequency of occurrence. The wind class methodology was originally...... developed for mesoscale modeling of wind resources. Its performance in connection with sampling of SAR scenes is tested against two sets of random SAR samples and meteorological observations at three sites in the North Sea during 2005–08. Predictions of the mean wind speed and the Weibull scale parameter...

  11. 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)

  12. Satellite Remote Sensing in Offshore Wind Energy

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Astrup, Poul

    2013-01-01

    capacity is found in the European Seas. The European Wind Energy Association, EWEA, expects the cumulative offshore capacity in Europe will reach 150 GW in year 2030. The offshore environment is far less well-known than over land and this increases the challenge of planning, operation and maintenance...

  13. Dynamics Analysis of Wind Energy Production Development

    Science.gov (United States)

    Berg, V. I.; Zakirzakov, A. G.; Gordievskaya, E. F.

    2017-01-01

    The paper presents the analysis of the introduction experience and dynamics development of the world wind energy production. Calculated the amount of wind energy sources investments and the production capacity growth dynamics of the wind turbines. The studies have shown that the introduction dynamics of new wind energy sources is higher than any other energy source.

  14. Wind waves in tropical cyclones: satellite altimeter observations and modeling

    Science.gov (United States)

    Golubkin, Pavel; Kudryavtsev, Vladimir; Chapron, Bertrand

    2016-04-01

    Results of investigation of wind-wave generation by tropical cyclones using satellite altimeter data are presented. Tropical cyclones are generally relatively small rapidly moving low pressure systems that are capable of generating severe wave conditions. Translation of a tropical cyclone leads to a prolonged period of time surface waves in the right sector remain under high wind forcing conditions. This effect has been termed extended fetch, trapped fetch or group velocity quasi-resonance. A tropical cyclone wave field is thus likely more asymmetrical than the corresponding wind field: wind waves in the tropical cyclone right sector are more developed with larger heights than waves in the left one. A dataset of satellite altimeter intersections of the Western Pacific tropical cyclones was created for 2010-2013. Data from four missions were considered, i.e., Jason-1, Jason-2, CryoSat-2, SARAL/AltiKa. Measurements in the rear-left and front-right sectors of tropical cyclones were examined for the presence of significant wave asymmetry. An analytical model is then derived to efficiently describe the wave energy distribution in a moving tropical cyclone. The model essentially builds on a generalization of the self-similar wave growth model and the assumption of a strongly dominant single spectral mode in a given quadrant of the storm. The model provides a criterion to anticipate wave enhancement with the generation of trapped abnormal waves. If forced during a sufficient timescale interval, also defined from this generalized self-similar wave growth model, waves can be trapped and large amplification of the wave energy will occur in the front-right storm quadrant. Remarkably, the group velocity and corresponding wavelength of outrunning wave systems will become wind speed independent and solely relate to the translating velocity. The resulting significant wave height also only weakly depends on wind speed, and more strongly on the translation velocity. Satellite

  15. New Approaches To Off-Shore Wind Energy Management Exploiting Satellite EO Data

    Science.gov (United States)

    Morelli, Marco; Masini, Andrea; Venafra, Sara; Potenza, Marco Alberto Carlo

    2013-12-01

    Wind as an energy resource has been increasingly in focus over the past decades, starting with the global oil crisis in the 1970s. The possibility of expanding wind power production to off-shore locations is attractive, especially in sites where wind levels tend to be higher and more constant. Off-shore high-potential sites for wind energy plants are currently being looked up by means of wind atlases, which are essentially based on NWP (Numerical Weather Prediction) archive data and that supply information with low spatial resolution and very low accuracy. Moreover, real-time monitoring of active off- shore wind plants is being carried out using in-situ installed anemometers, that are not very reliable (especially on long time periods) and that should be periodically substituted when malfunctions or damages occur. These activities could be greatly supported exploiting archived and near real-time satellite imagery, that could provide accurate, global coverage and high spatial resolution information about both averaged and near real-time off-shore windiness. In this work we present new methodologies aimed to support both planning and near-real-time monitoring of off-shore wind energy plants using satellite SAR(Synthetic Aperture Radar) imagery. Such methodologies are currently being developed in the scope of SATENERG, a research project funded by ASI (Italian Space Agency). SAR wind data are derived from radar backscattering using empirical geophysical model functions, thus achieving greater accuracy and greater resolution with respect to other wind measurement methods. In detail, we calculate wind speed from X-band and C- band satellite SAR data, such as Cosmo-SkyMed (XMOD2) and ERS and ENVISAT (CMOD4) respectively. Then, using also detailed models of each part of the wind plant, we are able to calculate the AC power yield expected behavior, which can be used to support either the design of potential plants (using historical series of satellite images) or the

  16. Satellite winds as a tool for offshore wind resource assessment: The Great Lakes Wind Atlas

    DEFF Research Database (Denmark)

    Doubrawa, Paula; Barthelmie, Rebecca Jane; Pryor, Sara C.

    2015-01-01

    , and interannual wind variability information, with time series that range from 3 to 11years in duration. Remotely-sensed equivalent neutral winds provide spatial information on the wind climate. NASA QuikSCAT winds are temporally consistent at a 25km resolution. ESA Synthetic Aperture Radar winds are temporally...... and combine all scenes into one wind speed map. QuikSCAT winds undergo a seasonal correction due to lack of data during the cold season that is based on its ratio relative to buoy time series. All processing steps reduce the biases of the individual maps relative to the buoy observed wind climates. The remote...

  17. Confidence intervals for annual wind power production******

    Directory of Open Access Journals (Sweden)

    Bensoussan Alain

    2014-01-01

    Full Text Available Wind power is an intermittent resource due to wind speed intermittency. However wind speed can be described as a stochastic process with short memory. This allows us to derive a central limit theorem for the annual or pluri-annual wind power production and then get quantiles of the wind power production for one, ten or twenty years future periods. On the one hand, the interquantile spread offers a measurement of the intrinsic uncertainties of wind power production. On the other hand, different quantiles with different periods of time are used by financial institutions to quantify the financial risk of the wind turbine. Our method is then applied to real datasets corresponding to a French wind turbine. Since confidence intervals can be enhanced by taking into account seasonality, we present some tools for change point analysis on wind series.

  18. Offshore Wind Resources Assessment from Multiple Satellite Data and WRF Modeling over South China Sea

    DEFF Research Database (Denmark)

    Chang, Rui; Rong, Zhu; Badger, Merete

    2015-01-01

    Using accurate inputs of wind speed is crucial in wind resource assessment, as predicted power is proportional to the wind speed cubed. This study outlines a methodology for combining multiple ocean satellite winds and winds from WRF simulations in order to acquire the accurate reconstructed...... offshore winds which can be used for offshore wind resource assessment. First, wind speeds retrieved from Synthetic Aperture Radar (SAR) and Scatterometer ASCAT images were validated against in situ measurements from seven coastal meteorological stations in South China Sea (SCS). The wind roses from...... (SD) of 2.09 m/s (1.83 m/s) and correlation coefficient of R 0.75 (0.80). When the offshore winds (i.e., winds directed from land to sea) are excluded, the comparison results for wind speeds show an improvement of SD and R, indicating that the satellite data are more credible over the open ocean...

  19. Assimilation of GMS-5 satellite winds using nudging method with MM5

    Institute of Scientific and Technical Information of China (English)

    GAO Shanhong; WU Zengmao; YANG Bo

    2006-01-01

    With the aid of Meteorological Information Composite and Processing System (MICAPS), satellite wind vectors derived from the Geostationary Meteorological Statellite-5 (GMS-5) and retrieved by National Satellite Meteorology Center of China (NSMC) can be obtained. Based on the nudging method built in the fifth-generation Mesoscale Model (MM5) of Pennsylvania State University and National Center for Atmospheric Research, a data preprocessor is developed to convert these satellite wind vectors to those with specified format required in MM5. To examine the data preprocessor and evaluate the impact of satellite winds from GMS-5 on MM5 simulations, a series of numerical experimental forecasts consisting of four typhoon cases in 2002 are designed and implemented. The results show that the preprocessor can process satellite winds smoothly and MM5 model runs successfully with a little extra computational load during ingesting these winds, and that assimilation of satellite winds by MM5 nudging method can obviously improve typhoon track forecast but contributes a little to typhoon intensity forecast. The impact of the satellite winds depends heavily upon whether the typhoon bogussing scheme in MM5 was turned on or not. The data preprocessor developed in this paper not only can treat GMS-5 satellite winds but also has capability with little modification to process derived winds from other geostationary satellites.

  20. Validation of satellite SAR offshore wind speed maps to in-situ data, microscala and mesoscale model results

    Energy Technology Data Exchange (ETDEWEB)

    Hasager, C.B.; Astrup, P.; Barthelmie, R.; Dellwik, E.; Hoffmann Joergensen, B.; Gylling Mortensen, N.; Nielsen, M.; Pryor, S.; Rathmann, O.

    2002-05-01

    A validation study has been performed in order to investigate the precision and accuracy of the satellite-derived ERS-2 SAR wind products in offshore regions. The overall project goal is to develop a method for utilizing the satellite wind speed maps for offshore wind resources, e.g. in future planning of offshore wind farms. The report describes the validation analysis in detail for three sites in Denmark, Italy and Egypt. The site in Norway is analyzed by the Nansen Environmental and Remote Sensing Centre (NERSC). Wind speed maps and wind direction maps from Earth Observation data recorded by the ERS-2 SAR satellite have been obtained from the NERSC. For the Danish site the wind speed and wind direction maps have been compared to in-situ observations from a met-mast at Horns Rev in the North Sea located 14 km offshore. The SAR wind speeds have been area-averaged by simple and advanced footprint modelling, ie. the upwind conditions to the meteorological mast are explicitly averaged in the SAR wind speed maps before comparison. The comparison results are very promising with a standard error of {+-} 0.61 m s{sup -1}, a bias {approx}2 m s{sup -1} and R{sup 2} {approx}0.88 between in-situ wind speed observations and SAR footprint averaged values at 10 m level. Wind speeds predicted by the local scale model LINCOM and the mesoscale model KAMM2 have been compared to the spatial variations in the SAR wind speed maps. The finding is a good correspondence between SAR observations and model results. Near the coast is an 800 m wide band in which the SAR wind speed observations have a strong negative bias. The bathymetry of Horns Rev combined with tidal currents give rise to bias in the SAR wind speed maps near areas of shallow, complex bottom topography in some cases. A total of 16 cases were analyzed for Horns Rev. For Maddalena in Italy five cases were analyzed. At the Italian site the SAR wind speed maps were compared to WAsP and KAMM2 model results. The WAsP model

  1. Wind farms production: Control and prediction

    Science.gov (United States)

    El-Fouly, Tarek Hussein Mostafa

    Wind energy resources, unlike dispatchable central station generation, produce power dependable on external irregular source and that is the incident wind speed which does not always blow when electricity is needed. This results in the variability, unpredictability, and uncertainty of wind resources. Therefore, the integration of wind facilities to utility electrical grid presents a major challenge to power system operator. Such integration has significant impact on the optimum power flow, transmission congestion, power quality issues, system stability, load dispatch, and economic analysis. Due to the irregular nature of wind power production, accurate prediction represents the major challenge to power system operators. Therefore, in this thesis two novel models are proposed for wind speed and wind power prediction. One proposed model is dedicated to short-term prediction (one-hour ahead) and the other involves medium term prediction (one-day ahead). The accuracy of the proposed models is revealed by comparing their results with the corresponding values of a reference prediction model referred to as the persistent model. Utility grid operation is not only impacted by the uncertainty of the future production of wind farms, but also by the variability of their current production and how the active and reactive power exchange with the grid is controlled. To address this particular task, a control technique for wind turbines, driven by doubly-fed induction generators (DFIGs), is developed to regulate the terminal voltage by equally sharing the generated/absorbed reactive power between the rotor-side and the gridside converters. To highlight the impact of the new developed technique in reducing the power loss in the generator set, an economic analysis is carried out. Moreover, a new aggregated model for wind farms is proposed that accounts for the irregularity of the incident wind distribution throughout the farm layout. Specifically, this model includes the wake effect

  2. A Novel Sampling Method for Satellite-Based Offshore Wind Resource Estimation

    DEFF Research Database (Denmark)

    Badger, Merete; Badger, Jake; Hasager, Charlotte Bay

    Synthetic aperture radar (SAR) measurements from satellites can be used to estimate the spatial wind speed variation offshore in great detail. The radar senses cm-scale roughness at the sea surface which can be translated to wind speed at the height 10 m using an empirical geophysical model......-based wind climatology have improved gradually as more data were collected. The satellite scenes have been treated as random samples and weighted equally in our previous analyses. Here we introduce a novel sampling strategy based on the wind class methodology that is normally applied in numerical modeling...... climatologically representative large-scale meteorological conditions for the region of interest. The wind classes are used to make the most representative selection of satellite images from the ENVISAT image catalogue. A minimum of one satellite image is chosen per wind class. The frequency of occurrence of each...

  3. Retrieval of vertical wind profiles during monsoon from satellite observed winds over the Indian Ocean using complex EOF analysis

    Indian Academy of Sciences (India)

    C M Kishtawal; Sujit Basu; S Karthikeyan

    2001-03-01

    The aim of this paper is to study the feasibility of deriving vertical wind profiles from current satellite observations. With this aim, we carried out complex empirical orthogonal function (CEOF) analysis of a large number of radiosonde observations of wind profiles over the Indian Ocean during the monsoon months. It has been found that the first two CEOFs explain 67% of the total variance in wind fields. While the first principal component is well correlated with the winds at 850 mb ( = 0.80), the second one is highly correlated with winds at 200 mb ( = 0.89). This analysis formed the basis of a retrieval algorithm which ensures the retrieval of vertical profiles of winds using satellite tracked cloud motion vector winds. Under the assumption that accurate measurements of wind are available at the above mentioned levels, the r.m.s. error of retrieval of each component of wind is estimated to range between 2ms-1 and 6ms-1 at different levels, which is much less than the natural variance of winds at these levels. For a better visualization of retrieval, we have provided retrieved and true wind profiles side by side for four typical synoptic conditions during the monsoon season.

  4. Assessment of wind products obtained from multiple microwave scatterometers over the China Seas

    Science.gov (United States)

    Wang, Zhixiong; Zhao, Chaofang

    2015-09-01

    Sea surface winds (SSWs) are vital to many meteorological and oceanographic applications, especially for regional study of short-range forecasting and Numerical Weather Prediction (NWP) assimilation. Spaceborne scatterometers can provide global ocean surface vector wind products at high spatial resolution. However, given the limited spatial coverage and revisit time for an individual sensor, it is valuable to study improvements of multiple microwave scatterometer observations, including the advanced scatterometer onboard parallel satellites MetOp-A (ASCAT-A) and MetOp-B (ASCAT-B) and microwave scatterometers aboard Oceansat-2 (OSCAT) and HY-2A (HY2-SCAT). These four scatterometer-derived wind products over the China Seas (0°-40°N, 105°-135°E) were evaluated in terms of spatial coverage, revisit time, bias of wind speed and direction, after comparison with ERA-Interim forecast winds from the European Centre for Medium-Range Weather Forecasts (ECMWF) and spectral analysis of wind components along the satellite track. The results show that spatial coverage of wind data observed by combination of the four sensors over the China Seas is about 92.8% for a 12-h interval at 12:00 and 90.7% at 24:00, respectively. The analysis of revisit time shows that two periods, from 5:30-8:30 UTC and 17:00-21:00 UTC each day, had no observations in the study area. Wind data observed by the four sensors along satellite orbits in one month were compared with ERA-Interim data, indicating that bias of both wind speed and direction varies with wind speed, especially for speeds less than 7 m/s. The bias depends on characteristics of each satellite sensor and its retrieval algorithm for wind vector data. All these results will be important as guidance in choosing the most suitable wind product for applications and for constructing blended SSW products.

  5. Short time ahead wind power production forecast

    Science.gov (United States)

    Sapronova, Alla; Meissner, Catherine; Mana, Matteo

    2016-09-01

    An accurate prediction of wind power output is crucial for efficient coordination of cooperative energy production from different sources. Long-time ahead prediction (from 6 to 24 hours) of wind power for onshore parks can be achieved by using a coupled model that would bridge the mesoscale weather prediction data and computational fluid dynamics. When a forecast for shorter time horizon (less than one hour ahead) is anticipated, an accuracy of a predictive model that utilizes hourly weather data is decreasing. That is because the higher frequency fluctuations of the wind speed are lost when data is averaged over an hour. Since the wind speed can vary up to 50% in magnitude over a period of 5 minutes, the higher frequency variations of wind speed and direction have to be taken into account for an accurate short-term ahead energy production forecast. In this work a new model for wind power production forecast 5- to 30-minutes ahead is presented. The model is based on machine learning techniques and categorization approach and using the historical park production time series and hourly numerical weather forecast.

  6. Wind characteristics in the North and Baltic Seas from the QuikSCAT satellite

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Pena Diaz, Alfredo; Badger, Merete

    2014-01-01

    is offshore wind energy, where accurate and frequent measurements are required for siting and operating modern wind farms. The greatest advantage of satellite observations rests in their extended spatial coverage. This paper presents analyses of the 10 year data set from QuikSCAT, for the overview of the wind...... for comparisons. Mean biases (in situ minus satellite) are close to zero for wind speed and -2.7° for wind direction with a standard deviation of 1.2 m s  − 1 and 15°, respectively. The impact of using QuikSCAT and in situ measurements extrapolated to 10 m for wind power density estimations is assessed......, accounting for possible influences of rain-contaminated retrievals, the sample size, the atmospheric stability effects and either fitting the Weibull distribution or obtaining the estimates from the time series of wind speed observations.Copyright © 2012 John Wiley & Sons, Ltd....

  7. Slow ions in plasma wind tunnels. [satellite-ionosphere interaction

    Science.gov (United States)

    Oran, W. A.; Stone, N. H.; Samir, U.

    1976-01-01

    One of the limitations of simulation experiments for the study of interaction between a satellite and its space environment is the background of slow ions in the plasma chamber. These ions appear to be created by charge exchange between the beam ions and residual neutral gas and may affect measurements of the current and potential in the wake. Results are presented for a plasma wind tunnel experiment to study the effect of slow ions on both the ion and electron current distribution and the electron temperature in the wake of a body in a streaming plasma. It is shown that the effect of slow ions for beam ion density not exceeding 3 is not significant for measurements of ion current variations in the wake zone. This is not the case when studies are aimed at the quantitative examination of electron current and temperature variations in the near wake zone. In these instances, the measurements of electron properties in the wake should be done at very low system pressures or over a range of system pressures in order to ascertain the influence of slow ions.

  8. WindSat satellite comparisons with nearshore buoy wind data near the U.S. west and east coasts

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; SHI Hanqing; YU Hong; YI Xin

    2016-01-01

    Nearshore wind speeds retrieved by WindSat are validated by a comparison with the moored buoy observations near the U.S. west and east coasts. A 30 min and 25 km collection window is used for the WindSat wind data and buoy measurements from January 2004 to December 2014. Comparisons show that the overall root-mean-square error is better than 1.44 m/s near the U.S. coasts, and the result for the east coast is better than that for the west coast. The retrieval accuracy of the descending portions is slightly better than that of the ascending portions. Most buoy-to-buoy variations are not significantly correlated with the coastal topography, the longitude and the distance from the shore or satellite-buoy separation distance. In addition, comparisons between a polarimetric microwave radiometer and a microwave scatterometer are accomplished with the nearshore buoy observations from 2007 to 2008. The WindSat-derived winds tend to be lower than the buoy observations near the U.S. coasts. In contrast, the QuikSCAT-derived winds tend to be higher than the buoy observations. Overall, the retrieval accuracy of WindSat is slightly better than that of QuikSCAT, and these satellite-derived winds are sufficiently accurate for scientific studies.

  9. CFOSAT: a new Chinese-French satellite for joint observations of ocean wind vector and directional spectra of ocean waves

    Science.gov (United States)

    Hauser, D.; Tison, C.; Amiot, T.; Delaye, L.; Mouche, A.; Guitton, G.; Aouf, L.; Castillan, P.

    2016-05-01

    CFOSAT (the China France Oceanography Satellite) is a joint mission from the Chinese and French Space Agencies, devoted to the observation ocean surface wind and waves so as to improve wind and wave forecast for marine meteorology, ocean dynamics modeling and prediction, climate variability knowledge, fundamental knowledge of surface processes. Currently under Phase D (manufacturing phase), the launch is now planned for mid-2018 the later. The CFOSAT will carry two payloads, both Ku-Band radar: the wave scatterometer (SWIM) and the wind scatterometer (SCAT). Both instruments are based on new concepts with respect to existing satellite-borne wind and wave sensors. Indeed, one of the originalities of CFOSAT is that it will provide simultaneously and in the same zone, the directional spectra of ocean waves and the wind vector. The concept used to measure the directional spectra of ocean waves has never been used from space until now: it is based on a near-nadir incidence pointing, rotating fan-beam radar, used in a real-aperture mode. In this paper we present the CFOSAT mission, its objectives and main characteristics. We then focus on the SWIM instrument, the expected geophysical products and performances. Finally, we present ongoing studies based on existing satellite data of directional spectra of ocean waves (Sentinel-1, ..) and carried out in preparation to CAL/VAL activities and to future data exploitation.

  10. a Diagnostic Approach to Obtaining Planetary Boundary Layer Winds Using Satellite-Derived Thermal Data

    Science.gov (United States)

    Belt, Carol Lynn

    The feasibility of using satellite-derived thermal data to generate realistic synoptic-scale winds within the planetary boundary layer (PBL) is examined. Diagnostic "modified Ekman" wind equations from the Air Force Global Weather Central (AFGWC) Boundary Layer Model are used to compute winds at seven levels within the PBL transition layer (50 m to 1600 m AGL). Satellite-derived winds based on 62 predawn (0921 GMT 19 April 1979) TIROS-N soundings are compared to similarly-derived wind fields based on 39 AVE-SESAME II rawinsonde (RAOB) soundings taken 2 h later. Actual wind fields are also used as a basis for comparison. Qualitative and statistical comparisons show that the Ekman winds from both sources are in very close agreement, with an average vector correlation coefficient of 0.815. Best results are obtained at 300 m AGL. Satellite winds tend to be slightly weaker than their RAOB counterparts and exhibit a greater degree of cross-isobaric flow. The modified Ekman winds show a significant improvement over geostrophic values at levels nearest the surface. Horizontal moisture divergence, moisture advection, velocity divergence and relative vorticity are computed at 300 m AGL using satellite-derived winds and moisture data. Results show excellent agreement with corresponding RAOB-derived values. Areas of horizontal moisture convergence, velocity convergence, and positive vorticity are nearly coincident and align in regions which later develop intense convection. Vertical motion at 1600 m AGL is computed using stepwise integration of the satellite winds through the PBL. Values and patterns are similar to those obtained using the RAOB-derived winds. Regions of maximum upward motion correspond with areas of greatest moisture convergence and the convection that later develops.

  11. Performance Indicators of Wind Energy Production

    CERN Document Server

    D'Amico, G; Prattico, F

    2015-01-01

    Modeling wind speed is one of the key element when dealing with the production of energy through wind turbines. A good model can be used for forecasting, site evaluation, turbines design and many other purposes. In this work we are interested in the analysis of the future financial cash flows generated by selling the electrical energy produced. We apply an indexed semi-Markov model of wind speed that has been shown, in previous investigation, to reproduce accurately the statistical behavior of wind speed. The model is applied to the evaluation of financial indicators like the Internal Rate of Return, semi-Elasticity and relative Convexity that are widely used for the assessment of the profitability of an investment and for the measurement and analysis of interest rate risk. We compare the computation of these indicators for real and synthetic data. Moreover, we propose a new indicator that can be used to compare the degree of utilization of different power plants.

  12. Satellite-based terrestrial production efficiency modeling

    Directory of Open Access Journals (Sweden)

    Obersteiner Michael

    2009-09-01

    Full Text Available Abstract Production efficiency models (PEMs are based on the theory of light use efficiency (LUE which states that a relatively constant relationship exists between photosynthetic carbon uptake and radiation receipt at the canopy level. Challenges remain however in the application of the PEM methodology to global net primary productivity (NPP monitoring. The objectives of this review are as follows: 1 to describe the general functioning of six PEMs (CASA; GLO-PEM; TURC; C-Fix; MOD17; and BEAMS identified in the literature; 2 to review each model to determine potential improvements to the general PEM methodology; 3 to review the related literature on satellite-based gross primary productivity (GPP and NPP modeling for additional possibilities for improvement; and 4 based on this review, propose items for coordinated research. This review noted a number of possibilities for improvement to the general PEM architecture - ranging from LUE to meteorological and satellite-based inputs. Current PEMs tend to treat the globe similarly in terms of physiological and meteorological factors, often ignoring unique regional aspects. Each of the existing PEMs has developed unique methods to estimate NPP and the combination of the most successful of these could lead to improvements. It may be beneficial to develop regional PEMs that can be combined under a global framework. The results of this review suggest the creation of a hybrid PEM could bring about a significant enhancement to the PEM methodology and thus terrestrial carbon flux modeling. Key items topping the PEM research agenda identified in this review include the following: LUE should not be assumed constant, but should vary by plant functional type (PFT or photosynthetic pathway; evidence is mounting that PEMs should consider incorporating diffuse radiation; continue to pursue relationships between satellite-derived variables and LUE, GPP and autotrophic respiration (Ra; there is an urgent need for

  13. Wind-driven changes of surface current, temperature, and chlorophyll observed by satellites north of New Guinea

    Science.gov (United States)

    Radenac, Marie-Hélène; Léger, Fabien; Messié, Monique; Dutrieux, Pierre; Menkes, Christophe; Eldin, Gérard

    2016-04-01

    Satellite observations of wind, sea level and derived currents, sea surface temperature (SST), and chlorophyll are used to expand our understanding of the physical and biological variability of the ocean surface north of New Guinea. Based on scarce cruise and mooring data, previous studies differentiated a trade wind situation (austral winter) when the New Guinea Coastal Current (NGCC) flows northwestward and a northwest monsoon situation (austral summer) when a coastal upwelling develops and the NGCC reverses. This circulation pattern is confirmed by satellite observations, except in Vitiaz Strait where the surface northwestward flow persists. We find that intraseasonal and seasonal time scale variations explain most of the variance north of New Guinea. SST and chlorophyll variabilities are mainly driven by two processes: penetration of Solomon Sea waters and coastal upwelling. In the trade wind situation, the NGCC transports cold Solomon Sea waters through Vitiaz Strait in a narrow vein hugging the coast. Coastal upwelling is generated in westerly wind situations (westerly wind event, northwest monsoon). Highly productive coastal waters are advected toward the equator and, during some westerly wind events, toward the eastern part of the warm pool. During El Niño, coastal upwelling events and northward penetration of Solomon Sea waters combine to influence SST and chlorophyll anomalies.

  14. Scenarios of hydrogen production from wind power

    Energy Technology Data Exchange (ETDEWEB)

    Klaric, Mario

    2010-09-15

    Since almost total amount of hydrogen is currently being produced from natural gas, other ways of cleaner and 'more renewable' production should be made feasible in order to make benchmarks for total 'hydrogen economy'. Hydrogen production from wind power combined with electrolysis imposes as one possible framework for new economy development. In this paper various wind-to-hydrogen scenarios were calculated. Cash flows of asset based project financing were used as decision making tool. Most important parameters were identified and strategies for further research and development and resource allocation are suggested.

  15. Offshore wind resource mapping for Europe by Synthetic Aperture Radar (SAR) satellite data

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete

    2015-01-01

    For the New European Wind Atlas (NEWA) project with 8 participating countries during5 years (March 2015 – March 2020) we will develop a new wind atlas covering most of the European countries as well as most of the offshore areas in Europe. For the offshore atlas we will rely on a combination...... of satellite remote sensing observations and atmospheric modelling. The satellite data include Synthetic Aperture Radar (SAR) from the European Space Agency from Envisat and the Copernicus mission Sentinel-1. SAR has the advantage of high spatial resolution such that we can cover near-coastal areas where many...... wind farms are planned. In the Danish RUNE project near-shore offshore winds are investigate from SAR, atmospheric modelling and ground-based remote sensing lidar. In the European Space Agency project ResGrow SAR wind resource maps at various locations in the European Seas are used to estimate the wind...

  16. Mapping Offshore Winds Around Iceland Using Satellite Synthetic Aperture Radar and Mesoscale Model Simulations

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Nawri, Nikolai

    2015-01-01

    The offshore wind climate in Iceland is examined based on satellite synthetic aperture radar (SAR), coastal meteorological station measurements, and results from two atmospheric model data sets, HARMONIE and NORA10. The offshore winds in Iceland are highly influenced by the rugged coastline. Lee...

  17. Strategic wind power trading considering rival wind power production

    OpenAIRE

    Exizidis, Lazaros; Kazempour, Jalal; Pinson, Pierre; Greve, Zacharie De; Vallée, Francois

    2016-01-01

    In an electricity market with high share of wind power, it is expected that wind power producers may exercise market power. However, wind producers have to cope with wind’s uncertain nature in order to optimally offer their generation,whereas in a market with more than one wind producers, uncertainty of rival wind power generation should also be considered. Under this context, this paper addresses the impact of rival wind producers on the offering strategy and profits of a pricemaker wind pro...

  18. Considering Air Density in Wind Power Production

    CERN Document Server

    Farkas, Zénó

    2011-01-01

    In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.

  19. Satellite SAR wind resource mapping in China (SAR-China)

    DEFF Research Database (Denmark)

    Badger, Merete

    The project ‘Off-Shore Wind Energy Resource Assessment and Feasibility Study of Off-Shore Wind Farm Development in China’ is funded by the EU-China Energy and Environment Programme (EEP) and runs for one year (August 2008 - August 2009). The project is lead by the China Meteorological Administrat...... offshore at a high spatial resolution (1 km). The detailed wind resource maps will be used, in combination with other data sets, for an assessment of potential sites for offshore wind farm development along the coastline from Fujian to Shandong in China....

  20. TIMED Doppler Interferometer on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite: Data product overview

    Science.gov (United States)

    Niciejewski, R.; Wu, Q.; Skinner, W.; Gell, D.; Cooper, M.; Marshall, A.; Killeen, T.; Solomon, S.; Ortland, D.

    2006-11-01

    The TIMED Doppler Interferometer (TIDI) performs the measurement of upper atmospheric winds on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. This is an optimized single etalon Fabry Perot interferometer that records the slight Doppler shift of individual emission features of the O2 (0,0) atmospheric band. The interferometer operates at a 100% duty cycle obtaining neutral wind altitude profiles on a global basis. The measurements are synoptic and provide an uninterrupted long-term climatological record of the dynamics in the mesosphere and lower thermosphere regions. The data products from TIDI include (1) apparent line of sight winds and integrated brightness, (2) inverted line of sight winds and volume emission rate, and (3) inverted horizontal neutral wind fields on an evenly spaced track angle/altitude grid. The data products demonstrate an interannual variability in the tidal structure of the mesosphere and the lower thermosphere and an inherent daily geophysical variance.

  1. A new strategic sampling for offshore wind assessment using radar satellite images

    Energy Technology Data Exchange (ETDEWEB)

    Beaucage, P.; Lafrance, G.; Bernier, M.; Lafrance, J. [Institut National de la Recherche Scientifique, Varennes, PQ (Canada); Choisnard, J. [Hydro-Quebec, Varennes, PQ (Canada)

    2007-07-01

    Synthetic Aperture Radar (SAR) satellite images have been used for offshore wind assessment. Several offshore wind farms are in operation or under construction in northern Europe. The European target for 2030 is 300 GW, of which half is intended for onshore and half for offshore development. Offshore projects in the east coast United States, the Gulf of Mexico and west coast of Canada are in the planning stage. Information obtained from SAR can be used to supplement current mapping methods of offshore wind energy resources. SAR is a useful tool to localize wind pattern over water surfaces. Other sources of offshore wind observations include meteorological stations such as buoys and masts; remote sensing instruments onboard satellites such as scatterometers (QuikSCAT, ASCAT) or passive microwave radiometers; and numerical weather prediction models. The synergy between scatterometers and SAR was discussed. The SAR system has been used for microscale resolution wind mapping in the Gaspe Peninsula. Strategic sampling zones were chosen in proximity to the QuikSCAT grid. It was concluded that 270 and 570 SAR images are needed to calculate average wind speed (U) and mean power output of a 3 MW wind turbine (P) over the Gaspe Peninsula region, respectively. It was concluded that microscale regional wind mapping can be produced at a lower cost with strategic sampling compared to random sampling. refs., tabs., figs.

  2. Strategic wind power trading considering rival wind power production

    DEFF Research Database (Denmark)

    Exizidis, Lazaros; Kazempour, Jalal; Pinson, Pierre

    2016-01-01

    In an electricity market with high share of wind power, it is expected that wind power producers may exercise market power. However, wind producers have to cope with wind’s uncertain nature in order to optimally offer their generation, whereas in a market with more than one wind producers......, uncertainty of rival wind power generation should also be considered. Under this context, this paper addresses the impact of rival wind producers on the offering strategy and profits of a pricemaker wind producer. A stochastic day-ahead market setup is considered, which optimizes the day-ahead schedules...... considering a number of foreseen real-time scenarios. The results indicate that strategic wind producer is more likely to exercise market power having a mid-mean or low-mean forecast distribution, rather than having a high-mean one. Furthermore, it is observed that its offering strategy varies considerably...

  3. Wind farm electrical power production model for load flow analysis

    Energy Technology Data Exchange (ETDEWEB)

    Segura-Heras, Isidoro; Escriva-Escriva, Guillermo; Alcazar-Ortega, Manuel [Institute for Energy Engineering, Universidad Politecnica de Valencia, Camino de Vera, s/n, edificio 8E, escalera F, 2a planta, 46022 Valencia (Spain)

    2011-03-15

    The importance of renewable energy increases in activities relating to new forms of managing and operating electrical power: especially wind power. Wind generation is increasing its share in the electricity generation portfolios of many countries. Wind power production in Spain has doubled over the past four years and has reached 20 GW. One of the greatest problems facing wind farms is that the electrical power generated depends on the variable characteristics of the wind. To become competitive in a liberalized market, the reliability of wind energy must be guaranteed. Good local wind forecasts are therefore essential for the accurate prediction of generation levels for each moment of the day. This paper proposes an electrical power production model for wind farms based on a new method that produces correlated wind speeds for various wind farms. This method enables a reliable evaluation of the impact of new wind farms on the high-voltage distribution grid. (author)

  4. Using Satellite SAR to Characterize the Wind Flow around Offshore Wind Farms

    Directory of Open Access Journals (Sweden)

    Charlotte Bay Hasager

    2015-06-01

    Full Text Available Offshore wind farm cluster effects between neighboring wind farms increase rapidly with the large-scale deployment of offshore wind turbines. The wind farm wakes observed from Synthetic Aperture Radar (SAR are sometimes visible and atmospheric and wake models are here shown to convincingly reproduce the observed very long wind farm wakes. The present study mainly focuses on wind farm wake climatology based on Envisat ASAR. The available SAR data archive covering the large offshore wind farms at Horns Rev has been used for geo-located wind farm wake studies. However, the results are difficult to interpret due to mainly three issues: the limited number of samples per wind directional sector, the coastal wind speed gradient, and oceanic bathymetry effects in the SAR retrievals. A new methodology is developed and presented. This method overcomes effectively the first issue and in most cases, but not always, the second. In the new method all wind field maps are rotated such that the wind is always coming from the same relative direction. By applying the new method to the SAR wind maps, mesoscale and microscale model wake aggregated wind-fields results are compared. The SAR-based findings strongly support the model results at Horns Rev 1.

  5. Icing Impacts on Wind Energy Production

    DEFF Research Database (Denmark)

    Davis, Neil

    and the turbine power loss. The model took the shape of a hierarchal model that combined a decision tree model, based on the existence of ice on the turbine blade, and two Generalized Additive Models (GAM). The GAM for periods where icing was forecast was found to include the terms wind speed, total ice mass...... forecasts. This thesis explores the impact of icing on produced power through observational analysis and numerical modeling. I begin by investigating the impact of icing on power production through observations. Since there are no direct observations of ice growth on the turbine blades, a methodology...... was developed for the identification of icing periods from the turbine power data and the nacelle wind speeds. This method was based on the spread of power production observations at cold temperatures that was not seen during warmer periods. Using the insights gained through the observational analysis...

  6. Using Satellite SAR to Characterize the Wind Flow around Offshore Wind Farms

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Vincent, Pauline; Badger, Jake

    2015-01-01

    Offshore wind farm cluster effects between neighboring wind farms increase rapidly with the large-scale deployment of offshore wind turbines. The wind farm wakes observed from Synthetic Aperture Radar (SAR) are sometimes visible and atmospheric and wake models are here shown to convincingly...... to interpret due to mainly three issues: the limited number of samples per wind directional sector, the coastal wind speed gradient, and oceanic bathymetry effects in the SAR retrievals. A new methodology is developed and presented. This method overcomes effectively the first issue and in most cases...

  7. Comparison of horizontal winds from the LIMS satellite instrument with rocket measurements

    Science.gov (United States)

    Smith, A. K.; Bailey, P. L.

    1985-01-01

    Statistical results are given for a comparison between horizontal geostrophic winds computed from satellite height data and all available in situ rocket wind soundings during a 7-month period. The satellite data are the daily mapped fields from the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) instrument, which extend from 100 to 0.1 mbar. Results indicate that in both the tropics and the extratropical Northern Hemisphere, the average zonal and meridional wind speeds agree to within 2-4 m/s throughout the stratosphere. The rms differences are much larger, with values of 5-10 m/s in the lower stratosphere, increasing to 20-40 m/s in the lower mesosphere. Time series show that LIMS and rocketsonde zonal wind speeds show coherent variations with temporal periods of 1-2 weeks and more, and both exhibit irregular variations on time scales of less than one week.

  8. Offshore Wind Energy: Wind and Sea Surface Temperature from Satellite Observations

    DEFF Research Database (Denmark)

    Karagali, Ioanna

    and the Baltic Sea. The aim is to evaluate their potential use and demonstrate their applicability within the context of offshore wind energy; for the quantication of the wind resources and for the identication of diurnal warming of the sea surface temperature. Space-borne observations of wind are obtained from...

  9. Study of hydrogen production from wind power in Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Aiche-Hamane, Lilia; Belhamel, Maiouf; Benyoucef, Boumedienne; Hamane, Mustapha [Centre for Development of Renewable Energies (CDER), Alger (Algeria)

    2010-07-01

    An overview of the potentiality of hydrogen production from wind power in Algeria has been given in this study. Wind resource assessment has been presented in cartographic form and windy sites have been identified for wind power application. A system constituted by a wind turbine, an electrolyser and a power conditioning device have been proposed for the study of hydrogen production in the southwest region of Algeria. For this purpose, the transient system simulation program (TRNSYS) have been used. The results obtained showed the sensitivity of hydrogen production to the wind resource trend and the importance of optimisation of the electrolyser according to the power produced by the wind turbine. (orig.)

  10. Two decades [1992-2012] of surface wind analyses based on satellite scatterometer observations

    Science.gov (United States)

    Desbiolles, Fabien; Bentamy, Abderrahim; Blanke, Bruno; Roy, Claude; Mestas-Nuñez, Alberto M.; Grodsky, Semyon A.; Herbette, Steven; Cambon, Gildas; Maes, Christophe

    2017-04-01

    Surface winds (equivalent neutral wind velocities at 10 m) from scatterometer missions since 1992 have been used to build up a 20-year climate series. Optimal interpolation and kriging methods have been applied to continuously provide surface wind speed and direction estimates over the global ocean on a regular grid in space and time. The use of other data sources such as radiometer data (SSM/I) and atmospheric wind reanalyses (ERA-Interim) has allowed building a blended product available at 1/4° spatial resolution and every 6 h from 1992 to 2012. Sampling issues throughout the different missions (ERS-1, ERS-2, QuikSCAT, and ASCAT) and their possible impact on the homogeneity of the gridded product are discussed. In addition, we assess carefully the quality of the blended product in the absence of scatterometer data (1992 to 1999). Data selection experiments show that the description of the surface wind is significantly improved by including the scatterometer winds. The blended winds compare well with buoy winds (1992-2012) and they resolve finer spatial scales than atmospheric reanalyses, which make them suitable for studying air-sea interactions at mesoscale. The seasonal cycle and interannual variability of the product compare well with other long-term wind analyses. The product is used to calculate 20-year trends in wind speed, as well as in zonal and meridional wind components. These trends show an important asymmetry between the southern and northern hemispheres, which may be an important issue for climate studies.

  11. Satellite SAR observation of the sea surface wind field caused by rain cells

    Institute of Scientific and Technical Information of China (English)

    YE Xiaomin; LIN Mingsen; YUAN Xinzhe; DING Jing; XIE Xuetong; ZHANG Yi; XU Ying

    2016-01-01

    Rain cells or convective rain, the dominant form of rain in the tropics and subtropics, can be easy detected by satellite Synthetic Aperture Radar (SAR) images with high horizontal resolution. The footprints of rain cells on SAR images are caused by the scattering and attenuation of the rain drops, as well as the downward airflow. In this study, we extract sea surface wind field and its structure caused by rain cells by using a RADARSAT-2 SAR image with a spatial resolution of 100 m for case study. We extract the sea surface wind speeds from SAR image by using CMOD4 geophysical model function with outside wind directions of NCEP final operational global analysis data, Advance Scatterometer (ASCAT) onboard European MetOp-A satellite and microwave scatterometer onboard Chinese HY-2 satellite, respectively. The root-mean-square errors (RMSE) of these SAR wind speeds, validated against NCEP, ASCAT and HY-2, are 1.48 m/s, 1.64 m/s and 2.14 m/s, respectively. Circular signature patterns with brighter on one side and darker on the opposite side on SAR image are interpreted as the sea surface wind speed (or sea surface roughness) variety caused by downdraft associated with rain cells. The wind speeds taken from the transect profile which superposes to the wind ambient vectors and goes through the center of the circular footprint of rain cell can be fitted as a cosine or sine curve in high linear correlation with the values of no less than 0.80. The background wind speed, the wind speed caused by rain cell and the diameter of footprint of the rain cell with kilometers or tens of kilometers can be acquired by fitting curve. Eight cases interpreted and analyzed in this study all show the same conclusion.

  12. Ocean Wind Fields from Satellite Active Microwave Sensors

    OpenAIRE

    Zecchetto, S.

    2010-01-01

    Scatterometer QuikSCAT data have been downloaded from the Physical Oceanography Distributed Active Archive Center (PODAAC) of the Jet Propulsion Laboratory, Pasadena, USA. The ASCAT data have been obtained from the Koninklijk Nederlands Meteorologisch Instituut (Dutch Meteorological Service KNMI, www.knmi.nl) operating in the framework of the Ocean & Sea Ice Satellite Application Facility (www.osi-saf.org) of EUMETSAT. The Envisat ASAR Wide Swath image has been downloaded from the ESA web ser...

  13. Winds observed in the Northern European seas with wind lidars, meteorological masts and satellite

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Stein, D.; Peña, Alfredo

    2013-01-01

    that for specific conditions, e.g. very stable atmosphere, the wind profiles can be heavily influenced by the boundary layer height at the 100 m level in the northern European seas. A very interesting part of the analysis includes the shear exponent (alpha) calculated during seasons, during 24-hours and for 12 wind...

  14. A satellite-borne radar wind sensor (RAWS)

    Science.gov (United States)

    Moore, Richard K.; Stuart, Michael; Propp, Timothy

    1993-01-01

    Modeling global atmospheric circulations and forecasting the weather would improve if worldwide information on winds aloft were available. Accurate prediction of weather is important to agriculture, shipping, air traffic, and many other fields. Global system models of climate are of great importance. Current global atmospheric models use pressure measurements and thermodynamic properties to calculate the effects of wind for use in Numerical Weather Prediction (NWP) models. Inputs to the NWP models are temperature, pressure and wind velocities at different heights. Clearly direct wind measurements could significantly improve the NWP model performance. The RAdar Wind Sounder (RAWS) program at the University of Kansas is a study of the feasibility and the trade-offs in the design of a space-based radar system to measure wind vectors. This can be done by measuring the Doppler shift of cloud and rain returns from three or more points and calculating the components of the wind vector. The RAWS study to date uses the candidate system selected after preliminary study of frequencies and sensitivities. Two frequencies chosen, 10 and 35 GHz, allow higher sensitivity for clouds and more penetration for rain. The past year was devoted to modeling the signal-to-noise ratio (SNR) achievable for the two frequencies. The determination of SNR versus cloud penetration depth used a cloud backscattering and attenuation model in the appropriate radar equation. Calculations assumed reasonable losses in reception and transmission, in addition to the atmospheric attenuation. We discovered that ice clouds provide a higher SNR than previously calculated, but some water clouds give lower SNRs than we calculated before. One of the primary issues in the SNR calculation was the choice of the drop size distribution. Although Xin used several distributions (e.g., log normal, Khrigian and Mazin), this year we used the Deirmendjian cloud model. SNR versus cloud penetration plots were generated to

  15. NOAA/NESDIS Satellite Derived Surface Oil Analysis Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NESDIS Experimental Marine Pollution Surveillance Report (EMPSR) and the Daily Composite product are new products of the NOAA Satellite Analysis Branch and...

  16. Multisensor satellite data integration for sea surface wind speed and direction determination

    Science.gov (United States)

    Glackin, D. L.; Pihos, G. G.; Wheelock, S. L.

    1984-01-01

    Techniques to integrate meteorological data from various satellite sensors to yield a global measure of sea surface wind speed and direction for input to the Navy's operational weather forecast models were investigated. The sensors were launched or will be launched, specifically the GOES visible and infrared imaging sensor, the Nimbus-7 SMMR, and the DMSP SSM/I instrument. An algorithm for the extrapolation to the sea surface of wind directions as derived from successive GOES cloud images was developed. This wind veering algorithm is relatively simple, accounts for the major physical variables, and seems to represent the best solution that can be found with existing data. An algorithm for the interpolation of the scattered observed data to a common geographical grid was implemented. The algorithm is based on a combination of inverse distance weighting and trend surface fitting, and is suited to combing wind data from disparate sources.

  17. Global relation between microwave satellite vegetation products and vegetation productivity

    Science.gov (United States)

    Teubner, Irene E.; Forkel, Matthias; Jung, Martin; Miralles, Diego G.; Dorigo, Wouter A.

    2017-04-01

    The occurrence of unfavourable environmental conditions like droughts commonly reduces the photosynthetic activity of ecosystems and, hence, their potential to take up carbon from the atmosphere. Ecosystem photosynthetic activity is commonly determined using remote sensing observations in the optical domain, which however have limitations particularly in regions of frequent cloud cover, e.g. the tropics. In this study, we explore the potential of vegetation optical depth (VOD) from microwave satellite observations as an alternative source for assessing vegetation productivity. VOD serves as an estimate for vegetation density and water content, which has an impact on plant physiological processes and hence should potentially provide a link to gross primary production (GPP). However, to date, it is unclear how microwave-retrieved VOD data and GPP data are related. We compare seasonal dynamics and anomalies of VOD retrievals from different satellite sensors and microwave frequencies with site level and global GPP estimates. We use VOD observations from active (ASCAT) and passive microwave sensors (AMSR-E, SMOS). We include eddy covariance measurements from the FLUXNET2015 dataset to assess the VOD products at site level. For a global scale analysis, we use the solar-induced chlorophyll fluorescence (SIF) observations from GOME-2 as a proxy for GPP and the FLUXCOM GPP product, which presents an upscaling of site measurements based on remote sensing data. Our results demonstrate that in general a good agreement between VOD and GPP or SIF exists. However, the strength of these relations depends on the microwave frequency, land cover type, and the time within the growing season. Correlations between anomalies of VOD and GPP or SIF support the assumption that microwave-derived VOD can be used to monitor vegetation productivity dynamics. The study is performed as part of the EOWAVE project funded by the Vienna University of Technology (http://eowave.geo.tuwien.ac.at/) and

  18. Optimization of wind farm power production using innovative control strategies

    DEFF Research Database (Denmark)

    Duc, Thomas

    Wind energy has experienced a very significant growth and cost reduction over the past decade, and is now able to compete with conventional power generation sources. New concepts are currently investigated to decrease costs of production of electricity even further. Wind farm coordinated control...... is one of them; it is aimed at increasing the efficiency of a wind farm and decreasing the fatigue loads faced by wind turbines by reducing aerodynamic interactions between them. These objectives are achieved considering two different strategies: curtailing an upwind turbine to reduce the wind speed...... conditions. It is therefore not known to what extent these gains can be reproduced in a real wind farm where wind conditions are very fluctuating. The French national project SMARTEOLE constitutes one of the first attempts of implementing these strategies on a full scale wind farm. A ten month measurement...

  19. Variability of the wind field in the tropical oceans as observed by satellite sensors

    Energy Technology Data Exchange (ETDEWEB)

    Grima, N.; Bentamy, A.; Quilfen, Y. [IFREMER/Brest, Plouzane (France)

    1995-12-31

    It is generally agreed today that the knowledge of the interaction between atmosphere and ocean is essential for understanding climate and ocean circulation, especially in tropical regions where the oceans are mainly and quickly influenced by wind action. The wind stress is the primary force driving the topical oceans from daily to interannual time scales. Conventional measurements from ships of the wind vectors are not available with a sufficient quality regarding the data accuracy as well as their coverage. Satellite observations of the surface wind over the sea are now available on a routine basis at the Institut Francais de Recherche pour l`Exploitation de la Mer (IFREMER), derived from the European Remote Sensing-1 (ERS-1) scatterometer and altimeter and from the radiometer Special Sensor Microwave/Imager (SSM/I). More than 3 years of weekly stress fields (1991--1994) with a resolution of one degree in latitude and longitude are produced using an objective analysis method. The accuracy of these gridded winds was evaluated by comparison with TAO buoys in the tropical Pacific area (Riou, 1995). The root mean square differences are of the order of 1.2 m/s and 15 degrees. The greatest differences are observed in the TOGA/COARE region where the wind variability is largest on the weekly scale. The low frequencies (monthly to interannual) of the wind variability are discussed and compared to those obtained from the TAO buoys. In this paper the time and space scales of the sea surface wind are described using a complex EOF analysis. One of the most interesting results is that the weekly averaged wind fields derived from ERS-1 scatterometer are useful to depict a 30--50-day oscillation over the tropical Pacific ocean.

  20. Solar and Wind Technologies for Hydrogen Production Report to Congress

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2005-12-01

    DOE's Solar and Wind Technologies for Hydrogen Production Report to Congress summarizes the technology roadmaps for solar- and wind-based hydrogen production. Published in December 2005, it fulfills the requirement under section 812 of the Energy Policy Act of 2005.

  1. High-resolution satellite-derived ocean surface winds in the Nordic-Barents seas region: Implications for ocean modeling (Invited)

    Science.gov (United States)

    Dukhovskoy, D. S.; Bourassa, M. A.; Hughes, P. J.

    2010-12-01

    High-resolution (0.25°) ocean surface wind velocity data derived from satellite observations are used to analyze winds in the Nordic-Barents seas during 2007-2008. For the analysis, a Cross-Calibrated, Multi-Platform (CCMP), multi-instrument ocean surface wind velocity data set is utilized. The product has been developed by National Aeronautics and Space Administration (NASA) within Making Earth Science data records for Use in Research Environments (MEaSUREs) Program. A variational method was used to combine wind measurements derived from satellite-born active and passive remote sensing instruments. In the objective procedure, winds from the European Centre for Medium-Range Weather Forecasts (ECMWF) Operational Analysis (DS111.1) were used as the background fields. The ocean surface wind fields are compared with those derived from the National Centers for Environmental Protection/National Center for Atmospheric Research (NCEP/NCAR) reanalysis. The NCEP/NCAR fields are commonly used to provide atmospheric forcing for Arctic Ocean models. The utility of using high-resolution winds in the ocean modeling is discussed. In particular, air-sea heat fluxes estimated from the two wind data sets are compared. It is anticipated that wind fields with higher spatial and temporal resolution will better resolve small-scale, short-lived atmospheric systems. As an example, the ice free region in the Nordic and Barents seas is frequently impacted by very intense cyclones known as “polar lows” with wind speeds near to or above gale force. A polar low forms over the sea and predominantly during the winter months. The size of these cyclones varies greatly from 100 to 1000 km. Presumably small-scale cyclones are misrepresented or not resolved in the NCAR fields leading to biases in the air-sea flux calculations in the ocean models. Inaccurate estimates of the air-sea fluxes eventually lead to biases in the Arctic Ocean model solutions.

  2. Wind power. Production in 2012; Vindkraft. Produksjon i 2012

    Energy Technology Data Exchange (ETDEWEB)

    Weir, David Edward; Nybakke, Karen

    2013-02-01

    In 2012 it was installed more wind power in Norway than in any year before. There was also production record with a total power generation from wind energy at ca. 1.57 TWh, equivalent to 1.1% of Norway's electricity production. 2012 was a relatively good 'wind year', with a production index of 107% for Norwegian wind farms as a whole. The length of time for wind was also relatively high compared to previous years with a national average of 2734 full load hours, corresponding to a capacity factor of 31%. Turbine availability also reached a record value of 95.6% in 2012 indicating more efficient operation of wind power plants in Norway.(eb)

  3. 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.

  4. Reliability of offshore wind power production under extreme wind conditions. Deliverable D 9.5. Work Package 9: Electrical grid

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Zeni, Lorenzo

    Reliability of offshore wind production under extreme wind conditions was investigated in this report. The wind power variability from existing and future large offshore wind farms in Western Denmark were simulated using the Correlated Wind model developed at Risø. The analysis was done for five ...... ramp rates and reserves requirements....

  5. Doppler Lidar Wind Value-Added Product

    Energy Technology Data Exchange (ETDEWEB)

    Newsom, R. K. [DOE ARM Climate Research Facility, Washington, DC (United States); Sivaraman, C. [DOE ARM Climate Research Facility, Washington, DC (United States); Shippert, T. R. [DOE ARM Climate Research Facility, Washington, DC (United States); Riihimaki, L. D. [DOE ARM Climate Research Facility, Washington, DC (United States)

    2015-07-01

    Wind speed and direction, together with pressure, temperature, and relative humidity, are the most fundamental atmospheric state parameters. Accurate measurement of these parameters is crucial for numerical weather prediction. Vertically resolved wind measurements in the atmospheric boundary layer are particularly important for modeling pollutant and aerosol transport. Raw data from a scanning coherent Doppler lidar system can be processed to generate accurate height-resolved measurements of wind speed and direction in the atmospheric boundary layer.

  6. Development of wind power production in arctic climate

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, E.; Kaas, J.; Aarnio, E. [Kemijoki Oy (Finland)

    1998-10-01

    The project Development of wind power production in arctic climate is a direct continuation of Arctic wind energy research project, which started in 1989. The main topics in 1996-97 have been production development and commercialising the blade heating systems, development of operation and maintenance practices of arctic wind power plants, preparations for new wind farms and various network connection and energy system studies. Practical operations have taken place in Pyhaetunturi test power plant and in Paljasselkae and Lammashovi power plants, which are in commercial operation

  7. World′s first telepathology experiments employing WINDS ultra-high-speed internet satellite, nicknamed "KIZUNA"

    Directory of Open Access Journals (Sweden)

    Takashi Sawai

    2013-01-01

    Full Text Available Background: Recent advances in information technology have allowed the development of a telepathology system involving high-speed transfer of high-volume histological figures via fiber optic landlines. However, at present there are geographical limits to landlines. The Japan Aerospace Exploration Agency (JAXA has developed the "Kizuna" ultra-high speed internet satellite and has pursued its various applications. In this study we experimented with telepathology in collaboration with JAXA using Kizuna. To measure the functionality of the Wideband InterNet working engineering test and Demonstration Satellite (WINDS ultra-high speed internet satellite in remote pathological diagnosis and consultation, we examined the adequate data transfer speed and stability to conduct telepathology (both diagnosis and conferencing with functionality, and ease similar or equal to telepathology using fiber-optic landlines. Materials and Methods: We performed experiments for 2 years. In year 1, we tested the usability of the WINDS for telepathology with real-time video and virtual slide systems. These are state-of-the-art technologies requiring massive volumes of data transfer. In year 2, we tested the usability of the WINDS for three-way teleconferencing with virtual slides. Facilities in Iwate (northern Japan, Tokyo, and Okinawa were connected via the WINDS and voice conferenced while remotely examining and manipulating virtual slides. Results: Network function parameters measured using ping and Iperf were within acceptable limits. However; stage movement, zoom, and conversation suffered a lag of approximately 0.8 s when using real-time video, and a delay of 60-90 s was experienced when accessing the first virtual slide in a session. No significant lag or inconvenience was experienced during diagnosis and conferencing, and the results were satisfactory. Our hypothesis was confirmed for both remote diagnosis using real-time video and virtual slide systems, and also

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

    Directory of Open Access Journals (Sweden)

    V. P. Kiliyanpilakkil

    2011-11-01

    showed a tendency toward leveling off, asymptotically approaching value of 0.15. The conclusions of this study regarding the aerosol extinction vs. wind speed relationship may have been influenced by the constant lidar ratio used for CALIPSO-derived AOD532. Nevertheless, active satellite sensor used in this study that allows separation of maritime wind induced component of AOD from the total AOD over the ocean could lead to improvements in optical properties of sea spray aerosols and their production mechanisms.

  9. Wind energy in electric power production, preliminary study

    Science.gov (United States)

    Lento, R.; Peltola, E.

    1984-01-01

    The wind speed conditions in Finland have been studied with the aid of the existing statistics of the Finnish Meteorological Institute. With the aid of the statistics estimates on the available wind energy were also made. Eight hundred wind power plants, 1.5 MW each, on the windiest west coast would produce about 2 TWh energy per year. Far more information on the temporal, geographical and vertical distribution of the wind speed than the present statistics included is needed when the available wind energy is estimated, when wind power plants are dimensioned optimally, and when suitable locations are chosen for them. The investment costs of a wind power plant increase when the height of the tower or the diameter of the rotor is increased, but the energy production increases, too. Thus, overdimensioning the wind power plant in view of energy needs or the wind conditions caused extra costs. The cost of energy produced by wind power can not yet compete with conventional energy, but the situation changes to the advantage of wind energy, if the real price of the plants decreases (among other things due to large series production and increasing experience), or if the real price of fuels rises. The inconvinience on the environment caused by the wind power plants is considered insignificant. The noise caused by the plant attenuates rapidly with distance. No harmful effects to birds and other animals caused by the wind power plants have been observed in the studies made abroad. Parts of the plant getting loose during an accident, or ice forming on the blades are estimated to fly even from a large plant only a few hundred meters.

  10. Correcting Errors in Catchment-Scale Satellite Rainfall Accumulation Using Microwave Satellite Soil Moisture Products

    Science.gov (United States)

    Ryu, D.; Crow, W. T.

    2011-12-01

    Streamflow forecasting in the poorly gauged or ungauged catchments is very difficult mainly due to the absence of the input forcing data for forecasting models. This challenge poses a threat to human safety and industry in the areas where proper warning system is not provided. Currently, a number of studies are in progress to calibrate streamflow models without relying on ground observations as an effort to construct a streamflow forecasting systems in the ungauged catchments. Also, recent advances in satellite altimetry and innovative application of the optical has enabled mapping streamflow rate and flood extent in the remote areas. In addition, remotely sensed hydrological variables such as the real-time satellite precipitation data, microwave soil moisture retrievals, and surface thermal infrared observations have the great potential to be used as a direct input or signature information to run the forecasting models. In this work, we evaluate a real-time satellite precipitation product, TRMM 3B42RT, and correct errors of the product using the microwave satellite soil moisture products over 240 catchments in Australia. The error correction is made by analyzing the difference between output soil moisture of a simple model forced by the TRMM product and the satellite retrievals of soil moisture. The real-time satellite precipitation products before and after the error correction are compared with the daily gauge-interpolated precipitation data produced by the Australian Bureau of Meteorology. The error correction improves overall accuracy of the catchment-scale satellite precipitation, especially the root mean squared error (RMSE), correlation, and the false alarm ratio (FAR), however, only a marginal improvement is observed in the probability of detection (POD). It is shown that the efficiency of the error correction is affected by the surface vegetation density and the annual precipitation of the catchments.

  11. Coherent Evaluation of Aerosol Data Products from Multiple Satellite Sensors

    Science.gov (United States)

    Ichoku, Charles

    2011-01-01

    Aerosol retrieval from satellite has practically become routine, especially during the last decade. However, there is often disagreement between similar aerosol parameters retrieved from different sensors, thereby leaving users confused as to which sensors to trust for answering important science questions about the distribution, properties, and impacts of aerosols. As long as there is no consensus, and the inconsistencies are not well characterized and understood, there will be no way of developing reliable model inputs and climate data records from satellite aerosol measurements. Fortunately, the Aerosol Robotic Network (AERONET) is providing well-calibrated globally representative ground-based aerosol measurements corresponding to the satellite-retrieved products. Through a recently developed web-based Multi-sensor Aerosol Products Sampling System (MAPSS), we are utilizing the advantages offered by collocated AERONET and satellite products to characterize and evaluate aerosol retrieval from multiple sensors. Indeed, MAPSS and its companion statistical tool AeroStat are facilitating detailed comparative uncertainty analysis of satellite aerosol measurements from Terra-MODIS, Aqua-MODIS, Terra-MISR, Aura-OMI, Parasol-POLDER, and Calipso-CALIOP. In this presentation, we will describe the strategy of the MAPSS system, its potential advantages for the aerosol community, and the preliminary results of an integrated comparative uncertainly analysis of aerosol products from multiple satellite sensors.

  12. Comparative analysis of wind energy production in Oklahoma

    Science.gov (United States)

    Ermilova, Ekaterina Alexeevna

    Scope and method of study. In the last decades humanity has realized the necessity of developing alternative energy sources for its efficient economic development and simple survival in the future. During the last 30 years major improvements were made in renewable energy technologies and they started to become competitive with traditional energy sources (fossil fuels), especially with consideration of external costs. Among the renewable energy sources, wind energy is one of the cheapest and fastest growing nowadays. Oklahoma is a very promising site for wind energy development considering its excellent wind resources. Developing wind energy can allow not only electricity production for in-state consumption, but also exporting to other states. The development of wind energy could encourage economic growth with very few adverse impacts on the environment. However, traditional energy sources are still the cheapest and, thus, the introduction of the wind energy in Oklahoma should be critically analyzed from economic, ecological and social points of view. The goal of this study is to conduct analysis of wind energy electricity production in Oklahoma on the four main stages: (1) Investment Analysis from Private Perspective: Calculate present value net benefits for wind energy and traditional energy (natural gas), make sure that both of them are positive. (2) Investment Analysis from Social Perspective: Evaluate present value net private benefits (PVNPB) and present value net social benefit from both projects (PVNSB). (3) Government Subsidy Analysis: recognize the necessity of the subsidies and evaluate the amount of subsidies if any. (4) Investment Analysis from a Geographic Perspective: determine economic feasibility of wind power generation for 77 Oklahoma counties. Findings and conclusions. The final output of the study is the recommendations concerning wind energy development in Oklahoma with consideration of economic efficiency, ecological and social impacts. Study

  13. Analysis and forecast experiments incorporating satellite soundings and cloud and water vapor drift wind information

    Science.gov (United States)

    Goodman, Brian M.; Diak, George R.; Mills, Graham A.

    1986-01-01

    A system for assimilating conventional meteorological data and satellite-derived data in order to produce four-dimensional gridded data sets of the primary atmospheric variables used for updating limited area forecast models is described. The basic principles of a data assimilation scheme as proposed by Lorenc (1984) are discussed. The design of the system and its incremental assimilation cycles are schematically presented. The assimilation system was tested using radiosonde, buoy, VAS temperature, dew point, gradient wind data, cloud drift, and water vapor motion data. The rms vector errors for the data are analyzed.

  14. Shrinkage of magnetosphere observed by TC-1 satellite during the high-speed solar wind stream

    Institute of Scientific and Technical Information of China (English)

    LI LiuYuan; CAO JinBin; ZHOU GuoCheng; YANG JunYing; YAN ChunXiao; ZHANG TieLong; H. REME; I. DANDOURAS; C. M. CARR

    2008-01-01

    During the interval 06:14-07:30 UT on August 24, 2005, since the Earth's magneto-pause was suddenly compressed by the persistent high-speed solar wind stream with the southward component of the interplanetary magnetic field (IMF), the magnetopause moved Inward for about 3.1 RE. Meanwhile, TC-1 satellite shifted from northern plasma sheet to the northern lobe/mantle region, although it kept Inward flying during the Interval 06:00-07:30UT. The shift of TC-1 from the plasma sheet to the lobe/mantle is caused by the simultaneous inward displacements of the plasma sheet and near-Earth lobe/mantle region, and their inward movement velocity is larger than the inward motion velocity of TC-1. The Joint inward dis-placements of the magnetopause, the lobe/mantle region and the plasma sheet indicate that the whole magnetosphere shrinks inward due to the magnetospheric compression by the high-speed solar wind stream, and the magnetospheric ions are attached to the magnetic field lines (i.e. 'frozen' in magnetic field) and move inward in the shrinking process of magnetosphere. The large shrinkage of magne-tosphere indicates that the near-Earth magnetotail compression caused by the strong solar wind dynamic pressure is much larger than its thickening caused by the southward component of the IMF, and the locations of magnetospheric regions with different plasmas vary remarkably with the variation of the solar wind dynamic pressure.

  15. Carbon stars and galactic chemical evolution: production of s-elements and wind heterogeneities

    Energy Technology Data Exchange (ETDEWEB)

    De Laverny, P [Observatoire de la Cote d' Azur, Dept. Cassiopee, UMR 6202, Nice (France)], E-mail: laverny@oca.eu

    2008-12-15

    Cool carbon stars found on the asymptotic giant branch are characterized by their production of specific chemical species and by strong but complex winds. This is illustrated below by (i) discussing their production of s-elements in the Milky Way and in neighbour satellite galaxies and (ii) describing the strong heterogeneities observed in the massive dusty circumstellar envelope of the nearby carbon star IRC+10216. Some similarities existing between the inner clumpy envelope of IRC+10216 with the dusty clumps recently detected around the more evolved variable stars of R Coronae Borealis type are also discussed.

  16. SimWIND: A Geospatial Infrastructure Model for Wind Energy Production and Transmission

    Science.gov (United States)

    Middleton, R. S.; Phillips, B. R.; Bielicki, J. M.

    2009-12-01

    Wind is a clean, enduring energy resource with a capacity to satisfy 20% or more of the electricity needs in the United States. A chief obstacle to realizing this potential is the general paucity of electrical transmission lines between promising wind resources and primary load centers. Successful exploitation of this resource will therefore require carefully planned enhancements to the electric grid. To this end, we present the model SimWIND for self-consistent optimization of the geospatial arrangement and cost of wind energy production and transmission infrastructure. Given a set of wind farm sites that satisfy meteorological viability and stakeholder interest, our model simultaneously determines where and how much electricity to produce, where to build new transmission infrastructure and with what capacity, and where to use existing infrastructure in order to minimize the cost for delivering a given amount of electricity to key markets. Costs and routing of transmission line construction take into account geographic and social factors, as well as connection and delivery expenses (transformers, substations, etc.). We apply our model to Texas and consider how findings complement the 2008 Electric Reliability Council of Texas (ERCOT) Competitive Renewable Energy Zones (CREZ) Transmission Optimization Study. Results suggest that integrated optimization of wind energy infrastructure and cost using SimWIND could play a critical role in wind energy planning efforts.

  17. Integration of satellite fire products into MPI Earth System Model

    Science.gov (United States)

    Khlystova, Iryna G.; Kloster, Silvia

    2013-04-01

    Fires are the ubiquitous phenomenon affecting all natural biomes. Since the beginning of the satellite Era, fires are being continuously observed from satellites. The most interesting satellite parameter retrieved from satellite measurements is the burned area. Combined with information on biomass available for burning the burned area can be translated into climate relevant carbon emissions from fires into the atmosphere. In this study we integrate observed burned area into a global vegetation model to derive global fire emissions. Global continuous burned area dataset is provided by the Global Fire Emissions Dataset (GFED). GFED products were obtained from MODIS (and pre-MODIS) satellites and are available for the time period of 14 years (1997-2011). This dataset is widely used, well documented and supported by periodical updates containing new features. We integrate the global burned area product into the land model JSBACH, a part of the Earth-System model developed at the Max Plank Institute for Meteorology. The land model JSBACH simulates land biomass in terms of carbon content. Fire is an important disturbance process in the Earth's carbon cycle and affects mainly the carbon stored in vegetation. In the standard JSBACH version fire is represented by process based algorithms. Using the satellite data as an alternative we are targeting better comparability of modeled carbon emissions with independent satellite measurements of atmospheric composition. The structure of burned vegetation inside of a biome can be described as the balance between woody and herbaceous vegetation. GFED provides in addition to the burned area satellite derived information of the tree cover distribution within the burned area. Using this dataset, we can attribute the burned area to the respective simulated herbaceous or woody biomass within the vegetation model. By testing several extreme cases we evaluate the quantitative impact of vegetation balance between woody and herbaceous

  18. Phase locking of wind turbines leads to intermittent power production

    Science.gov (United States)

    Anvari, M.; Wächter, M.; Peinke, J.

    2016-12-01

    Wind energy, inserted into the power grid by wind turbines, is strongly influenced by the turbulent fluctuations of wind speed in the atmospheric layer. Here we investigate the power production of a wind farm and show that due to the presence of large-scale and long-time correlation in wind velocity, turbines interact with each other. This interaction can result in phase locking in pairs of turbines. We show that there are time intervals during which some pairs of turbines are temporally phase locked. This intermediate phase locking leads to the statistical effect that the short-time fluctuations of the cumulative power output of the wind farm become non-Gaussian, i.e., intermittent power production occurs. Contrary to phase-locked states, there are some time intervals where all turbines are phase unlocking and consequently the probability density function of the temporal increment of cumulative power production of the wind farm has almost Gaussian distribution. The phase-locked states, which can be distinct from phase-unlocked states by their dynamical features, are evaluated by reconstructed stochastic differential equations.

  19. Eddy- and wind-sustained moderate primary productivity in the temperate East Sea (Sea of Japan

    Directory of Open Access Journals (Sweden)

    G.-H. Hong

    2013-06-01

    Full Text Available As part of the Dokdo East Sea Time Series Studies (DETS in the East/Japan Sea, a DETS buoy system was moored on the 130 m deep continental shelf off the Dok Islets in the central part of the East Sea. Chlorophyll a concentrations in the surface water observed by the DETS buoy system exhibited low-frequency bimodal variations in the annual chlorophyll a concentration due to a spring phytoplankton bloom and a smaller fall bloom. In addition, between late spring and early fall when the water column is stratified, frequent low-concentration maxima occurred, which appear to have been triggered by the injection of nutrient-rich subsurface water to the sunlit surface water. The primary productivity in the nutrient-depleted surface ocean was found to be enhanced by subsurface water upwelling where the wind and water move in the same direction as the mesoscale eddy. New observations in the East/Japan Sea based on time-series measurements of chlorophyll a, wind, and other oceanographic variables at fixed sites in the center of the sea and using satellite measurements reveal that the vertical movement of water caused by wind-eddy interactions depends on the relative angle between the wind and the water current. The wind-eddy interaction appears to contribute to the unusually high primary productivity in the region where it was often sustained by the long-lived warm and cold eddies.

  20. Satellite Observations of Wind Farm Impacts on Nocturnal Land Surface Temperature in Iowa

    Directory of Open Access Journals (Sweden)

    Ronald A. Harris

    2014-12-01

    Full Text Available Wind farms (WFs are believed to have an impact on lower boundary layer meteorology. A recent study examined satellite-measured land surface temperature data (LST and found a local nighttime warming effect attributable to a group of four large WFs in Texas. This study furthers their work by investigating the impacts of five individual WFs in Iowa, where the land surface properties and climate conditions are different from those in Texas. Two methods are used to assess WF impacts: first, compare the spatial coupling between the LST changes (after turbine construction versus before and the geographic layouts of the WFs; second, quantify the LST difference between the WFs and their immediate surroundings (non-WF areas. Each WF shows an irrefutable nighttime warming signal relative to the surrounding areas after their turbines were installed, and these warming signals are generally coupled with the geographic layouts of the wind turbines, especially in summer. This study provides further observational evidence that WFs can cause surface warming at nighttime, and that such a signal can be detected by satellite-based sensors.

  1. Efficient promotion of electricity production from offshore wind; Effiziente Foerderung der Stromerzeugung aus Offshore-Wind

    Energy Technology Data Exchange (ETDEWEB)

    Panzer, Christian; Auer, Hans; Lettner, Georg [Technische Univ. Wien (Austria). Energy Economics Group (EEG)

    2014-03-15

    Efficient promotion of electricity production from offshore wind stands in dynamic relationship with various influence factors, the most important of which are promotion instruments, topographic givens, regulation of grid connection, and supraregional market integration concepts. Using three case studies from different countries to highlight national differences in the promotion of offshore wind power plants the present analysis points out ways of improving the efficiency of promotion instruments.

  2. UV laser approach to doppler tropospheric wind sounding from a satellite

    Science.gov (United States)

    McKay, Jack A.; Wilkerson, Thomas D.; Heller, Donald F.; Walling, John C.

    1995-12-01

    The possibility of direct detection of tropospheric wind speed Doppler shift with an ultraviolet laser is considered. The use of the UV eliminates all practical concerns of eye safety, permits the use of uncooled detectors, and yields enhanced aerosol and Rayleigh backscatter signals. The Rayleigh signal, which in the free troposphere can exceed the aerosol signal by three orders of magnitude, is itself a candidate for wind speed measurement, despite the Doppler broadening of this signal. The basis of this approach is a diode-pumped, frequency-doubled alexandrite laser, which offers very high electrical to optical energy efficiency, an estimated 9%, in generating UV output. Efficiency is critical for a satellite based lidar system due to the size, cost, and mass of solar power generation and waste heat disposal subsystems. Pumping of alexandrite with 680 nm laser diodes has been demonstrated. Narrow linewidth, high spectral purity, and high frequency stability have been obtained with laser diode injection seeding of a ring alexandrite laser. The tunable diode laser control allows tuning of the laser for spacecraft velocity compensation. The potential performance of a wind sounding lidar scaled to match the 300 W power capability of a mid-sized satellite is evaluated for the extremely weak aerosol conditions of the southern hemisphere oceans. A 20 W output laser system, with 1 m aperture telescope, at 350 km altitude, may yield measurement precisions better than plus or minus 3 m/s through most of the troposphere, deteriorating to plus or minus 10 m/s under extreme conditions. A Rayleigh backscatter system will yield plus or minus 3 m/s precision to 8 km altitude, plus or minus 5 m/s at 15 km, even with zero aerosol content.

  3. CFOSAT: A new Chinese-French satellite for joint observations of ocean wind vector and directional spectra of ocean waves

    OpenAIRE

    Hauser, Danièle; Tison, Céline; Amiot, Thierry; Delaye, Lauriane; Mouche, Alexis; Guitton, Gilles; Aouf, Lotfi; Castillan, Patrick

    2016-01-01

    International audience; CFOSAT (the China France Oceanography Satellite) is a joint mission from the Chinese and French Space Agencies, devoted to the observation ocean surface wind and waves so as to improve wind and wave forecast for marine meteorology, ocean dynamics modeling and prediction, climate variability knowledge, fundamental knowledge of surface processes. Currently under Phase D (manufacturing phase), the launch is now planned for mid-2018 the later. The CFOSAT will carry two pay...

  4. Global mesospheric tidal winds observed by the high resolution Doppler imager on board the upper atmosphere research satellite

    Energy Technology Data Exchange (ETDEWEB)

    Morton, Y.T.; Lieberman, R.S.; Hays, P.B.; Ortland, D.A.; Marshall, A.R.; Wu, D.; Skinner, W.R.; Burrage, M.D.; Gell, D.A.; Yee, J.H.

    1993-06-18

    This paper presents results of mesospheric and lower thermospheric wind tides. The observations come from the high resolution doppler imager (HRDI) on board the upper atmosphere research satellite. From these observations, the authors report the observation of tidal effects on top of the meridonal winds observed in this region. Previous measurements have been mainly limited to radar measurements from fixed ground stations, which do not give consistent results, and do not provide a global picture of the wave structure.

  5. Shrinkage of magnetosphere observed by TC-1 satellite during the high-speed solar wind stream

    Institute of Scientific and Technical Information of China (English)

    H.; RME; I.; DANDOURAS; C.; M.; CARR

    2008-01-01

    During the interval 06:14―07:30 UT on August 24, 2005, since the Earth’s magneto- pause was suddenly compressed by the persistent high-speed solar wind stream with the southward component of the interplanetary magnetic field (IMF), the magnetopause moved inward for about 3.1 RE. Meanwhile, TC-1 satellite shifted from northern plasma sheet to the northern lobe/mantle region, although it kept inward flying during the interval 06:00―07:30UT. The shift of TC-1 from the plasma sheet to the lobe/mantle is caused by the simultaneous inward displacements of the plasma sheet and near-Earth lobe/mantle region, and their inward movement velocity is larger than the inward motion velocity of TC-1. The joint inward dis-placements of the magnetopause, the lobe/mantle region and the plasma sheet indicate that the whole magnetosphere shrinks inward due to the magnetospheric compression by the high-speed solar wind stream, and the magnetospheric ions are attached to the magnetic field lines (i.e. ‘frozen’ in magnetic field) and move inward in the shrinking process of magnetosphere. The large shrinkage of magne-tosphere indicates that the near-Earth magnetotail compression caused by the strong solar wind dynamic pressure is much larger than its thickening caused by the southward component of the IMF, and the locations of magnetospheric regions with different plasmas vary remarkably with the variation of the solar wind dynamic pressure.

  6. From wind ensembles to probabilistic information about future wind power production - results from an actual application

    DEFF Research Database (Denmark)

    Nielsen, Henrik Aalborg; Nielsen, Torben Skov; Madsen, Henrik

    2006-01-01

    horizon we aim at supplying quantiles of the wind power production conditional on the information available at the time at which the forecast is generated. This involves: (i) transformation of meteorological ensemble forecasts into wind power ensemble forecasts and (ii) calculation of quantiles based......Meteorological ensemble forecasts aim at quantifying the uncertainty of the future development of the weather by supplying several possible scenarios of this development. Here we address the use of such scenarios in probabilistic forecasting of wind power production. Specifically, for each forecast...... from (i) cannot be used directly and therefore both (i) and (ii) requires statistical modelling. Based on these findings an demo-application, supplying quantile forecasts for operational horizons of up to approximately 6 days, was developed for two utilities participating in a common project...

  7. Satellite-derived sea surface height and sea surface wind data fusion for spilled oil tracking

    Science.gov (United States)

    Kozai, Katsutoshi

    2003-12-01

    An attempt is made to estimate the trajectory of the spilled oil from the sunken tanker Nakhodka occurred on January 2, 1997 in the Japan Sea by fusing two microwave sensor data, namely ERS-2 altimeter and ADEOS/NSCAT scatterometer data. In this study 'fusion' is defined as the method of more reliable prediction for the trajectory of spilled oil than before. Geostrophic current vectors are derived from ERS-2 altimeter and wind-induced drift vectors are derived from ADEOS/NSCAT scatterometer data These two different satellite-derived vectors are 'fused' together in the surface current model to estimate and evaluate the trajectory of spilled oil from the sunken tanker Nakhodka. The distribution of component of spill vector is mostly accounted for by the distribution of geostrophic velocity component during the study period with some discrepancies during March, 1997.

  8. Wake Mitigation Strategies for Optimizing Wind Farm Power Production

    Science.gov (United States)

    Dilip, Deepu; Porté-Agel, Fernando

    2016-04-01

    Although wind turbines are designed individually for optimum power production, they are often arranged into groups of closely spaced turbines in a wind farm rather than in isolation. Consequently, most turbines in a wind farm do not operate in unobstructed wind flows, but are affected by the wakes of turbines in front of them. Such wake interference significantly reduces the overall power generation from wind farms and hence, development of effective wake mitigation strategies is critical for improving wind farm efficiency. One approach towards this end is based on the notion that the operation of each turbine in a wind farm at its optimum efficiency might not lead to optimum power generation from the wind farm as a whole. This entails a down regulation of individual turbines from its optimum operating point, which can be achieved through different methods such as pitching the turbine blades, changing the turbine tip speed ratio or yawing of the turbine, to name a few. In this study, large-eddy simulations of a two-turbine arrangement with the second turbine fully in the wake of the first are performed. Different wake mitigation techniques are applied to the upstream turbine, and the effects of these on its wake characteristics are investigated. Results for the combined power from the two turbines for each of these methods are compared to a baseline scenario where no wake mitigation strategies are employed. Analysis of the results shows the potential for improved power production from such wake control methods. It should be noted, however, that the magnitude of the improvement is strongly affected by the level of turbulence in the incoming atmospheric flow.

  9. Could Crop Roughness Impact the Wind Resource at Agriculturally Productive Wind Farm Sites?

    Science.gov (United States)

    Vanderwende, B. J.; Lundquist, J. K.

    2014-12-01

    The high concentration of both large-scale agriculture and wind power production in the United States Midwest region raises new questions concerning the interaction of the two activities. For instance, it is known from internal boundary layer theory that changes in the roughness of the land-surface resulting from crop choices could modify the momentum field aloft. Upward propagation of such an effect might impact the properties of the winds encountered by modern turbines, which typically span a layer from about 40 to 120 meters above the surface. As direct observation of such interaction would require impractical interference in the planting schedules of farmers, we use numerical modeling to quantify the magnitude of crop-roughness effects. To simulate a collocated farm and turbine array, we use version 3.4.1 of the Weather Research and Forecasting model (WRF). The hypothetical farm is inserted near the real location of the 2013 Crop Wind Energy Experiment (CWEX). Reanalyses provide representative initial and boundary conditions. A month-long period spanning August 2013 is used to evaluate the differences in flows above corn (maize) and soybean crops at the mature, reproductive stage. Simulations are performed comparing the flow above each surface regime, both in the absence and presence of a wind farm, which consists of a parameterized 11x11 array of 1.8 MW Vestas V90 turbines. Appreciable differences in rotor-layer wind speeds emerge. The use of soybeans results in an increase in wind speeds and a corresponding reduction in rotor-layer shear when compared to corn. Despite the turbulent nature of flow within a wind farm, high stability reduces the impact of crop roughness on the flow aloft, particularly in the upper portion of the rotor disk. We use these results to estimate the economic impact of crop selection on wind power producers.

  10. Assessing the utility of satellite-based whitecap fraction to estimate sea spray production and CO2 transfer velocity

    Science.gov (United States)

    Anguelova, M. D.

    2016-05-01

    The utility of a satellite-based whitecap database for estimates of surface sea spray production and bubble-mediated gas transfer on a global scale is presented. Existing formulations of sea spray production and bubble-mediated CO2 transfer velocity involve whitecap fraction parametrization as a function of wind speed at 10 m reference height W(U 10) based on photographic measurements of whitecaps. Microwave radiometric measurements of whitecaps from satellites provide whitecap fraction data over the world oceans for all seasons. Parametrizations W(U 10) based on such radiometric data are thus applicable for a wide range of conditions and can account for influences secondary to the primary forcing factor, the wind speed. Radiometric satellite-based W(U 10) relationship was used as input to: (i) the Coupled Ocean-Atmosphere Response Experiment Gas transfer (COAREG) algorithm to obtain CO2 transfer velocity and total CO2 flux; and (ii) the sea spray source function (SSSF) recommended by Andreas in 2002 to obtain fluxes of sea spray number and mass. The outputs of COAREG and SSSF obtained with satellite-based W(U 10) are compared with respective outputs obtained with the nominal W(U 10) relationship based on photographic data. Good comparisons of the gas and sea spray fluxes with direct measurements and previous estimates imply that the satellite- based whitecap database can be useful to obtain surface fluxes of particles and gases in regions and conditions difficult to access and sample in situ. Satellite and in situ estimates of surface sea spray production and bubble-mediated gas transfer thus complement each other: accurate in situ observations can constrain radiometric whitecap fraction and mass flux estimates, while satellite observations can provide global coverage of whitecap fraction and mass flux estimates.

  11. Forecasting Production Losses at a Swedish Wind Farm

    DEFF Research Database (Denmark)

    compared this statistical model with a simpler method that does not rely on a physical icing model. In that method meteorological icing is identified as periods when WRF forecasts clouds and the temperature is below freezing. During these periods it is assumed that there is no production from the turbines......, however as soon as the cloud goes away in the model we assume production returns to the idealized power curve. One unique aspect of the wind park we are working with is that it is not required to shut down when icing occurs. Therefore, during icing periods production still occurs, but below the idealized......Production loss due to icing has been identified as a problem both when siting turbines in cold climates, and when making forecasts of energy production for wind park management and energy markets. The Makkonen icing model (Makkonen, 2000), driven by output from the WRF mesoscale model, has been...

  12. Production process for advanced space satellite system cables/interconnects.

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza, Luis A.

    2007-12-01

    This production process was generated for the satellite system program cables/interconnects group, which in essences had no well defined production process. The driver for the development of a formalized process was based on the set backs, problem areas, challenges, and need improvements faced from within the program at Sandia National Laboratories. In addition, the formal production process was developed from the Master's program of Engineering Management for New Mexico Institute of Mining and Technology in Socorro New Mexico and submitted as a thesis to meet the institute's graduating requirements.

  13. A hybrid framework for verification of satellite precipitation products

    Science.gov (United States)

    Li, J.; Hsu, K.; AghaKouchak, A.; Sorooshian, S.

    2011-12-01

    Advances in satellite technology have led to the development of many remote-sensing algorithms to estimate precipitation at quasi-global scales. A number of satellite precipitation products are provided at high spatial and temporal resolutions that are suitable for short-term hydrologic applications. Several coordinated validation activities have been established to evaluate the accuracy of satellite precipitation. Traditional verification measures summarize pixel-to-pixel differences between observation and estimates. Object-based verification methods, however, extend pixel based validation to address errors related to spatial patterns and storm structure, such as the shape, volume, and distribution of precipitation rain-objects. In this investigation, a 2D watershed segmentation technique is used to identify rain storm objects and is further adopted in a hybrid verification framework to diagnose the storm-scale rainfall objects from both satellite-based precipitation estimates and ground observations (radar estimates). Five key scores are identified in the objective-based verification framework, including false alarm ratio, missing ratio, maximum of total interest, equal weight and weighted summation of total interest. These scores indicate the performance of satellite estimates with features extracted from the segmented storm objects. The proposed object-based verification framework was used to evaluate PERSIANN, PERSIANN-CCS, CMORPH, 3B42RT against NOAA stage IV MPE multi-sensor composite rain analysis. All estimates are evaluated at 0.25°x0.25° daily-scale in summer 2008 over the continental United States (CONUS). The five final scores for each precipitation product are compared with the median of maximum interest (MMI) of the Method for Object-Based Diagnostic Evaluation (MODE). The results show PERSIANN and CMORPH outperform 3B42RT and PERSIANN-CCS. Different satellite products presented distinct features of precipitation. For example, the sizes of

  14. Control design for an autonomous wind based hydrogen production system

    Energy Technology Data Exchange (ETDEWEB)

    Valenciaga, F.; Evangelista, C.A. [CONICET, Laboratorio de Electronica Industrial Control e Instrumentacion (LEICI), Facultad de Ingenieria, Universidad Nacional de La Plata, CC.91, C.P. 1900, La Plata (Argentina)

    2010-06-15

    This paper presents a complete control scheme to efficiently manage the operation of an autonomous wind based hydrogen production system. This system comprises a wind energy generation module based on a multipolar permanent magnet synchronous generator, a lead-acid battery bank as short term energy storage and an alkaline von Hoerner electrolyzer. The control is developed in two hierarchical levels. The higher control level or supervisor control determines the general operation strategy for the whole system according to the wind conditions and the state of charge of the battery bank. On the other hand, the lower control level includes the individual controllers that regulate the respective module operation assuming the set-points determined by the supervisor control. These last controllers are approached using second-order super-twisting sliding mode techniques. The performance of the closed-loop system is assessed through representative computer simulations. (author)

  15. Assessment of Off-shore Wind Energy Resource in China using QuikSCAT Satellite data and SAR Satellite Images

    DEFF Research Database (Denmark)

    Xiuzhi, Zhang; Yanbo, Shen; Jingwei, Xu;

    2010-01-01

    From August 2008 to August 2009, the project ‘Off-Shore Wind Energy Resource Assessment and Feasibility Study of Off-Shore Wind Farm Development in China’ was carried out by China Meteorological Administration (CMA), which was funded by the EU-China Energy and Environment Programme (EEP). As one ...

  16. Features of Ocean Surface Winds Observed by the QuikSCAT Satellite Before Tropical Cyclogenesis over the South China Sea

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; LAU Kai-Hon; FUNG Chi-Hung; ZHANG Qinghong

    2008-01-01

    Ocean surface winds observed by the Quick Scatterometer (QuikSCAT) satellite prior to the geneses of 36 tropical cy- clones (TCs) in the South China Sea (SCS) are investigated in this paper. The results show that there are areas with negative mean horizontal divergence around the TC genesis locations three days prior to TC formation. The divergence term [-(f+ζ)( u/ x+ v/ y)] in the vorticity equation is calculated based upon the QuikSCAT ocean surface wind data. The calculated mean divergence term is about 10.3 times the mean relative vorticity increase rate around the TC genesis position one day prior to TC genesis, which shows the important contributions of the divergence term to the vorticity increase prior to TC formation. It is suggested that criteria related with the divergence and divergence term be applied in early detections of tropical cyclogenesis using the QuikSCAT satellite data.

  17. Offshore Wind Resources Assessment from Multiple Satellite Data and WRF Modeling over South China Sea

    DEFF Research Database (Denmark)

    Chang, Rui; Rong, Zhu; Badger, Merete

    2015-01-01

    offshore winds which can be used for offshore wind resource assessment. First, wind speeds retrieved from Synthetic Aperture Radar (SAR) and Scatterometer ASCAT images were validated against in situ measurements from seven coastal meteorological stations in South China Sea (SCS). The wind roses from...

  18. Application of Satellite-Derived Wind Profiles to Joint Precision Airdrop System (JPADS) Operations

    Science.gov (United States)

    2010-03-01

    the Vertical Wind Profile ...............................................................59 Ekman Spiral Boundary Layer Wind Profile...61 37. Depiction of Ekman Spiral Wind Profile in the Boundary Layer .......................62 38. Thermal Winds with Ekman ...Menzel, et al., 1998) 23 In a paper detailing the application of GOES soundings to weather forecasting, W. Paul Menzel et al. describe the

  19. Online Assessment of Satellite-Derived Global Precipitation Products

    Science.gov (United States)

    Liu, Zhong; Ostrenga, D.; Teng, W.; Kempler, S.

    2012-01-01

    Precipitation is difficult to measure and predict. Each year droughts and floods cause severe property damages and human casualties around the world. Accurate measurement and forecast are important for mitigation and preparedness efforts. Significant progress has been made over the past decade in satellite precipitation product development. In particular, products' spatial and temporal resolutions as well as timely availability have been improved by blended techniques. Their resulting products are widely used in various research and applications. However biases and uncertainties are common among precipitation products and an obstacle exists in quickly gaining knowledge of product quality, biases and behavior at a local or regional scale, namely user defined areas or points of interest. Current online inter-comparison and validation services have not addressed this issue adequately. To address this issue, we have developed a prototype to inter-compare satellite derived daily products in the TRMM Online Visualization and Analysis System (TOVAS). Despite its limited functionality and datasets, users can use this tool to generate customized plots within the United States for 2005. In addition, users can download customized data for further analysis, e.g. comparing their gauge data. To meet increasing demands, we plan to increase the temporal coverage and expanded the spatial coverage from the United States to the globe. More products have been added as well. In this poster, we present two new tools: Inter-comparison of 3B42RT and 3B42 Inter-comparison of V6 and V7 TRMM L-3 monthly products The future plans include integrating IPWG (International Precipitation Working Group) Validation Algorithms/statistics, allowing users to generate customized plots and data. In addition, we will expand the current daily products to monthly and their climatology products. Whenever the TRMM science team changes their product version number, users would like to know the differences by

  20. Wind Power Ramping Product for Increasing Power System Flexibility

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Mingjian; Zhang, Jie; Wu, Hongyu; Hodge, Bri-Mathias; Ke, Deping; Sun, Yuanzhang

    2016-05-05

    With increasing penetrations of wind power, system operators are concerned about a potential lack of system flexibility and ramping capacity in real-time dispatch stages. In this paper, a modified dispatch formulation is proposed considering the wind power ramping product (WPRP). A swinging door algorithm (SDA) and dynamic programming are combined and used to detect WPRPs in the next scheduling periods. The detected WPRPs are included in the unit commitment (UC) formulation considering ramping capacity limits, active power limits, and flexible ramping requirements. The modified formulation is solved by mixed integer linear programming. Numerical simulations on a modified PJM 5-bus System show the effectiveness of the model considering WPRP, which not only reduces the production cost but also does not affect the generation schedules of thermal units.

  1. Optimal Control to Increase Energy Production of Wind Farm Considering Wake Effect and Lifetime Estimation

    DEFF Research Database (Denmark)

    Tian, Jie; Zhou, Dao; Su, Chi;

    2017-01-01

    In a wind farm, the upstream wind turbine may cause power loss to the downstream wind turbines due to the wake effect. Meanwhile, the energy production is determined by the power generation and the lifetime of the wind turbine. In this paper, an optimal active power control method is proposed...... to maximize the energy production of wind farms by considering the wake effect and the lifetime of wind turbine. It starts with the analysis of the pitch angle curve and active power curve seen from the Maximum Power Point Tracking (MPPT) of individual wind turbines. Taking the wake effect into account......, the pitch angle curve and active power curve are optimized with the aim of Maximum Power Generation (MPG) of the wind farm. Afterwards, considering the lifetime of wind turbines, a comparison is offered between the MPPT method and the MPG method for energy production using a simplified two-turbine wind farm...

  2. Application of Geostatistical Simulation to Enhance Satellite Image Products

    Science.gov (United States)

    Hlavka, Christine A.; Dungan, Jennifer L.; Thirulanambi, Rajkumar; Roy, David

    2004-01-01

    With the deployment of Earth Observing System (EOS) satellites that provide daily, global imagery, there is increasing interest in defining the limitations of the data and derived products due to its coarse spatial resolution. Much of the detail, i.e. small fragments and notches in boundaries, is lost with coarse resolution imagery such as the EOS MODerate-Resolution Imaging Spectroradiometer (MODIS) data. Higher spatial resolution data such as the EOS Advanced Spaceborn Thermal Emission and Reflection Radiometer (ASTER), Landsat and airborne sensor imagery provide more detailed information but are less frequently available. There are, however, both theoretical and analytical evidence that burn scars and other fragmented types of land covers form self-similar or self-affine patterns, that is, patterns that look similar when viewed at widely differing spatial scales. Therefore small features of the patterns should be predictable, at least in a statistical sense, with knowledge about the large features. Recent developments in fractal modeling for characterizing the spatial distribution of undiscovered petroleum deposits are thus applicable to generating simulations of finer resolution satellite image products. We will present example EOS products, analysis to investigate self-similarity, and simulation results.

  3. Validation of SMOS Satellite Soil Moisture Products over Tropical Region

    Science.gov (United States)

    Kanniah, Kasturi; Siang, Kang Chuen

    2016-07-01

    Calibration and validation (cal/val) activities on Soil Moisture and Ocean Salinity (SMOS) satellite derived soil moisture products has been conducted worldwide since the data has become available but not over the tropical region . This study focuses on the installation of a soil moisture data collection network over an agricultural site in a tropical region in Peninsular Malaysia, and the validation of SMOS soil moisture products. The in-situ data over one year period was analysed and validation of SMOS Soil Moisture products with these in-situ data was conducted.Bias and root mean square errors (RMSE) were computed between SMOS soil moisture products and the in-situ surface soil moisture collected at the satellite passing time (6 am and 6 pm local time). Due to the known limitations of SMOS soil moisture retrieval over vegetated areas with vegetation water content higher than 5 kgm-2, overestimation of SMOS soil moisture products to in-situ data was noticed in this study. The bias is ranging from 0.064 to 0.119 m3m-3 and the RMSE is from 0.090 to 0.158 m3m-3, when both ascending and descending data were validated. This RMSE was found to be similar to a number of studies conducted previously at different regions. However a wet bias was found during the validation, while previous validation activities at other regions showed dry biases. The result of this study is useful to support the continuous development and improvement of SMOS soil moisture retrieval model, aims to produce soil moisture products with higher accuracy, especially in the tropical region.

  4. NOAA high resolution sea surface winds data from Synthetic Aperture Radar (SAR) on the RADARSAT-2 satellite

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Synthetic Aperture Radar (SAR)-derived high resolution wind products are calculated from high resolution SAR images of normalized radar cross section (NRCS) of the...

  5. Utilizing Satellite-derived Precipitation Products in Hydrometeorological Applications

    Science.gov (United States)

    Liu, Z.; Ostrenga, D.; Teng, W. L.; Kempler, S. J.; Huffman, G. J.

    2012-12-01

    Each year droughts and floods happen around the world and can cause severe property damages and human casualties. Accurate measurement and forecast are important for preparedness and mitigation efforts. Through multi-satellite blended techniques, significant progress has been made over the past decade in satellite-based precipitation product development, such as, products' spatial and temporal resolutions as well as timely availability. These new products are widely used in various research and applications. In particular, the TRMM Multi-satellite Precipitation Analysis (TMPA) products archived and distributed by the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) provide 3-hourly, daily and monthly near-global (50° N - 50° S) precipitation datasets for research and applications. Two versions of TMPA products are available, research (3B42, 3B43, rain gauge adjusted) and near-real-time (3B42RT). At GES DISC, we have developed precipitation data services to support hydrometeorological applications in order to maximize the TRMM mission's societal benefits. In this presentation, we will present examples of utilizing TMPA precipitation products in hydrometeorological applications including: 1) monitoring global floods and droughts; 2) providing data services to support the USDA Crop Explorer; 3) support hurricane monitoring activities and research; and 4) retrospective analog year analyses to improve USDA's world agricultural supply and demand estimates. We will also present precipitation data services that can be used to support hydrometeorological applications including: 1) User friendly TRMM Online Visualization and Analysis System (TOVAS; URL: http://disc2.nascom.nasa.gov/Giovanni/tovas/); 2) Mirador (http://mirador.gsfc.nasa.gov/), a simplified interface for searching, browsing, and ordering Earth science data at GES DISC; 3) Simple Subset Wizard (http://disc.sci.gsfc.nasa.gov/SSW/ ) for data subsetting and format conversion; 4) Data

  6. Estimates of lightning NOx production from GOME satellite observations

    Directory of Open Access Journals (Sweden)

    K. F. Boersma

    2005-01-01

    Full Text Available Tropospheric NO2 column retrievals from the Global Ozone Monitoring Experiment (GOME satellite spectrometer are used to quantify the source strength and 3-D distribution of lightning produced nitrogen oxides (NOx=NO+NO2. A sharp increase of NO2 is observed at convective cloud tops with increasing cloud top height, consistent with a power-law behaviour with power 5±2. Convective production of clouds with the same cloud height are found to produce NO2 with a ratio 1.6/1 for continents compared to oceans. This relation between cloud properties and NO2 is used to construct a 10:30 local time global lightning NO2 production map for 1997. An extensive statistical comparison is conducted to investigate the capability of the TM3 chemistry transport model to reproduce observed patterns of lightning NO2 in time and space. This comparison uses the averaging kernel to relate modelled profiles of NO2 to observed NO2 columns. It exploits a masking scheme to minimise the interference of other NOx sources on the observed total columns. Simulations are performed with two lightning parameterizations, one relating convective preciptation (CP scheme to lightning flash distributions, and the other relating the fifth power of the cloud top height (H5 scheme to lightning distributions. The satellite-retrieved NO2 fields show significant correlations with the simulated lightning contribution to the NO2 concentrations for both parameterizations. Over tropical continents modelled lightning NO2 shows remarkable quantitative agreement with observations. Over the oceans however, the two model lightning parameterizations overestimate the retrieved NO2 attributed to lightning. Possible explanations for these overestimations are discussed. The ratio between satellite-retrieved NO2 and modelled lightning NO2 is used to rescale the original modelled lightning NOx production. Eight estimates of the lightning NOx production in 1997 are obtained from spatial and temporal

  7. Estimates of lightning NOx production from GOME satellite observations

    Directory of Open Access Journals (Sweden)

    H. M. Kelder

    2005-05-01

    Full Text Available Tropospheric NO2 column retrievals from the Global Ozone Monitoring Experiment (GOME satellite spectrometer are used to quantify the source strength and 3D distribution of lightning produced nitrogen oxides (NOx=NO2+NO2. A sharp increase of NO2 is observed at convective cloud tops with increasing cloud top height, consistent with a power-law behaviour with power 5±2. Convective production of clouds with the same cloud height are found to produce NO2 with a ratio 1.6/1 for continents compared to oceans. This relation between cloud properties and NO2 is used to construct a 10:30 local time global lightning NO2 production map for 1997. An extensive statistical comparison is conducted to investigate the capability of the TM3 chemistry transport model to reproduce observed patterns of lightning NO2 in time and space. This comparison uses the averaging kernel to relate modelled profiles of NO2 to observed NO2 columns. It exploits a masking scheme to minimise the interference of other NOx sources on the observed total columns. Simulations are performed with two lightning parametrisations, one relating convective preciptation (CP scheme to lightning flash distributions, and the other relating the fifth power of the cloud top height (H5 scheme to lightning distributions. The satellite-retrieved NO2 fields show significant correlations with the simulated lightning contribution to the NO2 concentrations for both parametrisations. Over tropical continents modelled lightning NO2 shows remarkable quantitative agreement with observations. Over the oceans however, the two model lightning parametrisations overestimate the retrieved NO2 attributed to lightning. Possible explanations for these overestimations are discussed. The ratio between satellite-retrieved NO2 and modelled lightning NO2 is used to rescale the original modelled lightning NOx production. Eight estimates of the lightning NOx production in 1997 are obtained from spatial and temporal correlation

  8. Linking oil production to surface subsidence from satellite radar interferometry

    Science.gov (United States)

    Xu, Haibin; Dvorkin, Jack; Nur, Amos

    Land subsidence over the Belridge and Lost Hills oil fields, Southern California, was measured using spaceborne interferometric synthetic aperture radar (InSAR). During the 105-day period between 11/5/95 and 2/17/96, the subsidence in the center of the Lost Hills field reached 15 cm. We assume that this surface subsidence resulted from the vertical shrinkage of the reservoir, which in turn was due to oil production and the resulting pore pressure drop. We model this mechanical effect using an elastic deformation theoretical solution with input constants taken from relevant experiments. The modeled surface deformation matches the InSAR measured values. This result indicates that it is possible, in principle, to monitor hydrocarbon production using satellite-based measurements of earth deformation.

  9. Ocean surface waves and winds over the north Indian Ocean from satellite altimeter - preliminary results of SAC-NIO joint project

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; Rajkumar, R.; Gairola, R.M.; Gohil, B.S.; Vethamony, P.; Rao, L.V.G.

    and NIO. Though there had been three cruises during the period, there were very few satellite-ship overlaps. Data pairs (satellite derived and in situ) of surface wind speed, significant wave height and minimum significant swell height were used to find...

  10. An error analysis of tropical cyclone divergence and vorticity fields derived from satellite cloud winds on the Atmospheric and Oceanographic Information Processing System (AOIPS)

    Science.gov (United States)

    Hasler, A. F.; Rodgers, E. B.

    1977-01-01

    An advanced Man-Interactive image and data processing system (AOIPS) was developed to extract basic meteorological parameters from satellite data and to perform further analyses. The errors in the satellite derived cloud wind fields for tropical cyclones are investigated. The propagation of these errors through the AOIPS system and their effects on the analysis of horizontal divergence and relative vorticity are evaluated.

  11. Assessment of satellite rainfall products over the Andean plateau

    Science.gov (United States)

    Satgé, Frédéric; Bonnet, Marie-Paule; Gosset, Marielle; Molina, Jorge; Hernan Yuque Lima, Wilson; Pillco Zolá, Ramiro; Timouk, Franck; Garnier, Jérémie

    2016-01-01

    Nine satellite rainfall estimations (SREs) were evaluated for the first time over the South American Andean plateau watershed by comparison with rain gauge data acquired between 2005 and 2007. The comparisons were carried out at the annual, monthly and daily time steps. All SREs reproduce the salient pattern of the annual rain field, with a marked north-south gradient and a lighter east-west gradient. However, the intensity of the gradient differs among SREs: it is well marked in the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis 3B42 (TMPA-3B42), Precipitation Estimation from remotely Sensed Information using Artificial Neural Networks (PERSIANN) and Global Satellite Mapping of Precipitation (GSMaP) products, and it is smoothed out in the Climate prediction center MORPHing (CMORPH) products. Another interesting difference among products is the contrast in rainfall amounts between the water surfaces (Lake Titicaca) and the surrounding land. Some products (TMPA-3B42, PERSIANN and GSMaP) show a contradictory rainfall deficit over Lake Titicaca, which may be due to the emissivity contrast between the lake and the surrounding lands and warm rain cloud processes. An analysis differentiating coastal Lake Titicaca from inland pixels confirmed this trend. The raw or Real Time (RT) products have strong biases over the study region. These biases are strongly positive for PERSIANN (above 90%), moderately positive for TMPA-3B42 (28%), strongly negative for CMORPH (- 42%) and moderately negative for GSMaP (- 18%). The biases are associated with a deformation of the rain rate frequency distribution: GSMaP underestimates the proportion of rainfall events for all rain rates; CMORPH overestimates the proportion of rain rates below 2 mm day- 1; and the other products tend to overestimate the proportion of moderate to high rain rates. These biases are greatly reduced by the gauge adjustment in the TMPA-3B42, PERSIANN and CMORPH products, whereas a

  12. MISTiC Winds: A micro-satellite constellation approach to high resolution observations of the atmosphere using infrared sounding and 3D winds measurements

    Science.gov (United States)

    Maschhoff, K. R.; Polizotti, J. J.; Aumann, H. H.; Susskind, J.

    2016-09-01

    MISTiCTM Winds is an approach to improve short-term weather forecasting based on a miniature high resolution, wide field, thermal emission spectrometry instrument that will provide global tropospheric vertical profiles of atmospheric temperature and humidity at high (3-4 km) horizontal and vertical ( 1 km) spatial resolution. MISTiC's extraordinarily small size, payload mass of less than 15 kg, and minimal cooling requirements can be accommodated aboard a 27U-class CubeSat or an ESPA-Class micro-satellite. Low fabrication and launch costs enable a LEO sunsynchronous sounding constellation that would collectively provide frequent IR vertical profiles and vertically resolved atmospheric motion vector wind observations in the troposphere. These observations are highly complementary to present and emerging environmental observing systems, and would provide a combination of high vertical and horizontal resolution not provided by any other environmental observing system currently in operation. The spectral measurements that would be provided by MISTiC Winds are similar to those of NASA's AIRS that was built by BAE Systems and operates aboard the AQUA satellite. These new observations, when assimilated into high resolution numerical weather models, would revolutionize short-term and severe weather forecasting, save lives, and support key economic decisions in the energy, air transport, and agriculture arenas-at much lower cost than providing these observations from geostationary orbit. In addition, this observation capability would be a critical tool for the study of transport processes for water vapor, clouds, pollution, and aerosols. Key remaining technical risks are being reduced through laboratory and airborne testing under NASA's Instrument Incubator Program.

  13. MISTiC Winds, a Micro-Satellite Constellation Approach to High Resolution Observations of the Atmosphere using Infrared Sounding and 3D Winds Measurements

    Science.gov (United States)

    Maschhoff, K. R.; Polizotti, J. J.; Susskind, J.; Aumann, H. H.

    2015-12-01

    MISTiCTM Winds is an approach to improve short-term weather forecasting based on a miniature high resolution, wide field, thermal emission spectrometry instrument that will provide global tropospheric vertical profiles of atmospheric temperature and humidity at high (3-4 km) horizontal and vertical ( 1 km) spatial resolution. MISTiC's extraordinarily small size, payload mass of less than 15 kg, and minimal cooling requirements can be accommodated aboard a 27U-class CubeSat or an ESPA-Class micro-satellite. Low fabrication and launch costs enable a LEO sun-synchronous sounding constellation that would collectively provide frequent IR vertical profiles and vertically resolved atmospheric motion vector wind observations in the troposphere. These observations are highly complementary to present and emerging environmental observing systems, and would provide a combination of high vertical and horizontal resolution not provided by any other environmental observing system currently in operation. The spectral measurements that would be provided by MISTiC Winds are similar to those of NASA's Atmospheric Infrared Sounder that was built by BAE Systems and operates aboard the AQUA satellite. These new observations, when assimilated into high resolution numerical weather models, would revolutionize short-term and severe weather forecasting, save lives, and support key economic decisions in the energy, air transport, and agriculture arenas-at much lower cost than providing these observations from geostationary orbit. In addition, this observation capability would be a critical tool for the study of transport processes for water vapor, clouds, pollution, and aerosols. Key technical risks are being reduced through laboratory and airborne testing under NASA's Instrument Incubator Program.

  14. The Solar Wind Charge-Exchange Production Factor for Hydrogen

    CERN Document Server

    Kuntz, K D; Collier, M R; Connor, H K; Cravens, T E; Koutroumpa, D; Porter, F S; Robertson, I P; Sibeck, D G; Snowden, S L; Thomas, N E; Wash, B M

    2015-01-01

    The production factor, or broad band averaged cross-section, for solar wind charge-exchange with hydrogen producing emission in the ROSAT 1/4 keV (R12) band is $3.8\\pm0.2\\times10^{-20}$ count degree$^{-2}$ cm$^4$. This value is derived from a comparison of the Long-Term (background) Enhancements in the ROSAT All-Sky Survey with magnetohysdrodynamic simulations of the magnetosheath. This value is 1.8 to 4.5 times higher than values derived from limited atomic data, suggesting that those values may be missing a large number of faint lines. This production factor is important for deriving the exact amount of 1/4 keV band flux that is due to the Local Hot Bubble, for planning future observations in the 1/4 keV band, and for evaluating proposals for remote sensing of the magnetosheath. The same method cannot be applied to the 3/4 keV band as that band, being composed primarily of the oxygen lines, is far more sensitive to the detailed abundances and ionization balance in the solar wind. We also show, incidentally,...

  15. A preliminary assessment of the sea surface wind speed production of HY-2 scanning microwave radiometer

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiaoqi; ZHU Jianhua; LIN Mingsen; ZHAO Yili; WANG He; CHEN Chuntao; PENG Hailong; ZHANG Youguang

    2014-01-01

    A scanning microwave radiometer (RM) was launched on August 16, 2011, on board HY-2 satellite. The six-month long global sea surface wind speeds observed by the HY-2 scanning microwave radiometer are preliminarily validated using in-situ measurements and WindSat observations, respectively, from January to June 2012. The wind speed root-mean-square (RMS) difference of the comparisons with in-situ data is 1.89 m/s for the measurements of NDBC and 1.72 m/s for the recent four-month data measured by PY30-1 oil platform, respectively. On a global scale, the wind speeds of HY-2 RM are compared with the sea surface wind speeds derived from WindSat, the RMS difference of 1.85 m/s for HY-2 RM collocated observations data set is calculated in the same period as above. With analyzing the global map of a mean difference between HY-2 RM and WindSat, it appears that the bias of the sea surface wind speed is obviously higher in the inshore regions. In the open sea, there is a relatively higher positive bias in the mid-latitude regions due to the overestimation of wind speed observations, while the wind speeds are underestimated in the Southern Ocean by HY-2 RM relative to WindSat observations.

  16. How Good Are Satellite Rainfall Products For Hydrologic Simulations Of A Small Watershed?

    Science.gov (United States)

    Zeweldi, D. A.; Gebremichael, M.; Downer, C. W.

    2009-12-01

    Despite recent advances in satellite rainfall technology, the use of satellite rainfall products for hydrological applications is very limited. Assessing the potential and utility of satellite rainfall products is crucially important to advance their utility. In this work, first we quantify the errors in satellite rainfall products. We considered different satellite rainfall algorithms; namely, CMORPH (~8km, 30-minute), PERSIANN-CCS (4km, hourly) and HydroEstimator (10 km, hourly). Second, we assess how these errors propagate to hydrologic model streamflow simulations. We used the fully-distributed hydrologic model known as GSSHA. Our study region is the Goodwin Creek experimental watershed (21 sq. km) in Mississippi, USA. Our results provide information on how good different satellite rainfall products are for hydrologic simulations of a small watershed.

  17. NWP Impact of Cloud Top and Boundary Layer Winds from a Satellite Borne Lidar: an Observing System Simulation Experiment

    Science.gov (United States)

    Isaacs, R. G.; Grassotti, C.; Hoffman, R. N.; Mickelson, M.; Nehrkorn, T.; Louis, J.-F.

    1992-01-01

    Observing systems simulation experiments (OSSE's) provide a powerful tool to assess the impact of proposed satellite borne observing systems on meteorological applications models. We describe the results of an OSSE conducted to assess the impact of data from a low power lidar wind sensor on the forecast accuracy of a global spectral numerical weather prediction (NWP) model, the Air Force Geophysics Laboratory Global Data Assimilation System. The instrument would be operating at near-infrared wavelengths thereby increasing the backscatter signal relative to comparable infrared lidar.

  18. Classification of Dust Days by Satellite Remotely Sensed Aerosol Products

    Science.gov (United States)

    Sorek-Hammer, M.; Cohen, A.; Levy, Robert C.; Ziv, B.; Broday, D. M.

    2013-01-01

    Considerable progress in satellite remote sensing (SRS) of dust particles has been seen in the last decade. From an environmental health perspective, such an event detection, after linking it to ground particulate matter (PM) concentrations, can proxy acute exposure to respirable particles of certain properties (i.e. size, composition, and toxicity). Being affected considerably by atmospheric dust, previous studies in the Eastern Mediterranean, and in Israel in particular, have focused on mechanistic and synoptic prediction, classification, and characterization of dust events. In particular, a scheme for identifying dust days (DD) in Israel based on ground PM10 (particulate matter of size smaller than 10 nm) measurements has been suggested, which has been validated by compositional analysis. This scheme requires information regarding ground PM10 levels, which is naturally limited in places with sparse ground-monitoring coverage. In such cases, SRS may be an efficient and cost-effective alternative to ground measurements. This work demonstrates a new model for identifying DD and non-DD (NDD) over Israel based on an integration of aerosol products from different satellite platforms (Moderate Resolution Imaging Spectroradiometer (MODIS) and Ozone Monitoring Instrument (OMI)). Analysis of ground-monitoring data from 2007 to 2008 in southern Israel revealed 67 DD, with more than 88 percent occurring during winter and spring. A Classification and Regression Tree (CART) model that was applied to a database containing ground monitoring (the dependent variable) and SRS aerosol product (the independent variables) records revealed an optimal set of binary variables for the identification of DD. These variables are combinations of the following primary variables: the calendar month, ground-level relative humidity (RH), the aerosol optical depth (AOD) from MODIS, and the aerosol absorbing index (AAI) from OMI. A logistic regression that uses these variables, coded as binary

  19. Examination of water budget using satellite products over Australia

    Science.gov (United States)

    Wang, Hailong; Guan, Huade; Gutiérrez-Jurado, Hugo A.; Simmons, Craig T.

    2014-04-01

    Large-scale water balance in the Australian continent is examined over an 8-year period (2003-2010) with three commonly used satellite based water cycle components: precipitation (P) from the Tropical Rainfall Measuring Mission (TRMM), evapotranspiration (ET) from the Moderate Resolution Imaging Spectroradiometer (MODIS), and terrestrial water storage change (ΔS) from the Gravity Recovery and Climate Experiment (GRACE). First we evaluate the water balance using the three products over areas with limited annual streamflow to eliminate the influence of runoff in the analysis. We observe more frequent and better closure and consistency in the water balance from the three components over the central part of Western Australia, where low precipitation, high elevation and low relief exist. The data are more coherent at seasonal and annual scales compared to the monthly scale. Application of the three products in Lake Eyre Basin (an internal drainage system) suggests a maximum 6.2 mm/year groundwater inflow to the basin, which is consistent with the regional groundwater flow direction in the area. This result also indicates that the absolute integrated error of the combination of three products should be smaller than 6.2 mm/year, which is about 2.1% of annual precipitation in the basin. If this relative error is assumed for the whole continent, water balance calculation using the three products over the whole Australian continent results in 144.7 ± 11.3 mm/year estimated total runoff to the surrounding oceans during the study period. We found that this estimate is comparable to the estimates of 50-150 mm/year from the Australian Bureau of Meteorology and National Water Commission.

  20. Forecasting wind power production from a wind farm using the RAMS model

    DEFF Research Database (Denmark)

    Tiriolo, L.; Torcasio, R. C.; Montesanti, S.;

    2015-01-01

    The importance of wind power forecast is commonly recognized because it represents a useful tool for grid integration and facilitates the energy trading. This work considers an example of power forecast for a wind farm in the Apennines in Central Italy. The orography around the site is complex...... and the horizontal resolution of the wind forecast has an important role. To explore this point we compared the performance of two 48 h wind power forecasts using the winds predicted by the Regional Atmospheric Modeling System (RAMS) for the year 2011. The two forecasts differ only for the horizontal resolution...... of the ECMWF Integrated Forecasting System (IFS), whose horizontal resolution over Central Italy is about 25 km at the time considered in this paper. Because wind observations were not available for the site, the power curve for the whole wind farm was derived from the ECMWF wind operational analyses available...

  1. Optimal Control to Increase Energy Production of Wind Farm Considering Wake Effect and Lifetime Estimation

    DEFF Research Database (Denmark)

    Tian, Jie; Zhou, Dao; Su, Chi

    2017-01-01

    , the pitch angle curve and active power curve are optimized with the aim of Maximum Power Generation (MPG) of the wind farm. Afterwards, considering the lifetime of wind turbines, a comparison is offered between the MPPT method and the MPG method for energy production using a simplified two-turbine wind farm...

  2. Operational risk of a wind farm energy production by Extreme Value Theory and Copulas

    CERN Document Server

    D'Amico, Guglielmo; Prattico, Flavio

    2014-01-01

    In this paper we use risk management techniques to evaluate the potential effects of those operational risks that affect the energy production of a wind farm. We concentrate our attention on three major risk factors: wind speed uncertainty, wind turbine reliability and interactions of wind turbines due mainly to their placement. As a first contribution, we show that the Weibull distribution, commonly used to fit recorded wind speed data, underestimates rare events. Therefore, in order to achieve a better estimation of the tail of the wind speed distribution, we advance a Generalized Pareto distribution. The wind turbines reliability is considered by modeling the failures events as a compound Poisson process. Finally, the use of Copula able us to consider the correlation between wind turbines that compose the wind farm. Once this procedure is set up, we show a sensitivity analysis and we also compare the results from the proposed procedure with those obtained by ignoring the aforementioned risk factors.

  3. Potential Offshore Wind Energy Applications for Enhanced Resolution Scatterometer Products (Invited)

    Science.gov (United States)

    Plagge, A. M.; Epps, B.

    2013-12-01

    The multi-decadal record of ocean surface vector winds provided by scatterometer measurements is a valuable resource that has been underutilized by the wind energy sector. Previously, these data were not considered applicable for offshore wind energy analysis; chiefly, the sensors' low resolution limited their desirability. Now, however, enhanced products provide high quality wind vectors at resolutions between 3 and 5km. Potential energy applications currently under investigation include (1) validation of existing commercial wind resource assessment models, (2) investigations of interactions between large existing wind farms and the atmospheric boundary layer including attempts to identify wakes, and (3) an extension of previous studies comparing SAR and scatterometer wind fields with regard to specific wind energy concerns, including wind spectra and Weibull parameters.

  4. Assessment of wind resources and annual energy production of wind farms

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay

    Wind energy provides a significant share of EU’s renewable energy source. It is anticipated in the European Commission (EC), the International Energy Agency (IEA), and the European Wind Energy Association (EWEA) that wind energy expands further. Wind energy has had an annual growth of 15.6% during...... the last 17 years. In Denmark the plan is to increase to 50% share of total electricity consumption in 2020 compared to 26% in 2011. In EU this was 6.3% in 2011. In EU new installed wind power was 9 GW and 0.8 GW, onshore and offshore, respectively, in 2011. The total capacity in Europe is 96 GW...

  5. Operational costs induced by fluctuating wind power production in Germany and Scandinavia

    DEFF Research Database (Denmark)

    Meibom, Peter; Weber, C.; Barth, R.

    2009-01-01

    and will therefore influence the operational costs induced by wind power production. A method is applied for calculating the change in operational costs due to wind power production using a stochastic optimisation model covering the power systems in Germany and the Nordic countries. Two cases of alternative......Adding wind power generation in a power system changes the operational patterns of the existing units due to the variability and partial predictability of wind power production. For large amounts of wind power production, the expectation is that the specific operational costs (fuel costs, start......-up costs, variable operation and maintenance costs, costs of consuming CO2 emission permits) of the other power plants will increase due to more operation time in part-load and more start-ups. The change in operational costs induced by the wind power production can only be calculated by comparing...

  6. Analysis of the potential for hydrogen production in the province of Cordoba, Argentina, from wind resources

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, C.R.; Santa Cruz, R.; Aisa, S. [Universidad Empresarial Siglo 21, Monsenor Pablo Cabrera s/n calle, 5000 Cordoba (Argentina); Riso, M.; Jimenez Yob, G.; Ottogalli, R. [Subsecretaria de Infraestructuras y Programas, Ministerio de Obras y Servicios Publicos del Gobierno de la Provincia de Cordoba, Av. Poeta Lugones 12, 2do. Piso, 5000 Cordoba (Argentina); Jeandrevin, G. [Instituto Universitario Aeronautico, Avenida Fuerza Aerea km 6 1/2, 5022 Cordoba (Argentina); Leiva, E.P.M. [INFIQC, Unidad de Matematica y Fisica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Haya de la Torre s/n, 5010 Cordoba (Argentina)

    2010-06-15

    The potential for hydrogen production from wind resources in the province of Cordoba, second consumer of fossil fuels for transportation in Argentina, is analyzed. Three aspects of the problem are considered: the evaluation of the hydrogen resource from wind power, the analysis of the production costs via electrolysis and the annual requirements of wind energy to generate hydrogen to fuel the vehicular transport of the province. Different scenarios were considered, including pure hydrogen as well as the so-called CNG plus, where hydrogen is mixed with compressed natural gas in a 20% V/V dilution of the former. The potential for hydrogen production from wind resources is analyzed for each department of the province, excluding those regions not suited for wind farms. The analysis takes into account the efficiency of the electrolyzer and the capacity factor of the wind power system. It is concluded that the automotive transportation could be supplied by hydrogen stemming from wind resources via electrolysis. (author)

  7. Low Speed PSP Testing in Production Wind Tunnels

    Science.gov (United States)

    Bell, James; Mehta, Rabi; Schairer, Ed; Hand, Larry; Nixon, David (Technical Monitor)

    1998-01-01

    The brightness signal from a pressure-sensitive paint varies inversely with absolute pressure. Consequently high signal-to-noise ratios are required to resolve aerodynamic pressure fields at low speeds, where the pressure variation around an object might only be a few percent of the mean pressure. This requirement is unavoidable, and implies that care must be taken to minimize noise sources present in the measurement. This paper discusses and compares the main noise sources in low speed PSP testing using the "classical" intensity-based single-luminophore technique. These are: temperature variation, model deformation, and lamp drift/paint degradation. Minimization of these error sources from the point of view of operation in production wind tunnels is discussed, with some examples from recent tests in NASA Ames facilities.

  8. Offshore Wind Power Production in Critical Weather Conditions

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Sørensen, Poul Ejnar

    2012-01-01

    Critical weather conditions, i.e. extreme winds will raise a lot of challenges when it comes to the secure operation of the whole European electric system with the future large scale offshore wind power. This is especially true for Denmark where the target is that wind power should provide 50...

  9. Validation and Upscaling of Soil Moisture Satellite Products in Romania

    Science.gov (United States)

    Sandric, I.; Diamandi, A.; Oana, N.; Saizu, D.; Vasile, C.; Lucaschi, B.

    2016-06-01

    The study presents the validation of SMOS soil moisture satellite products for Romania. The validation was performed with in-situ measurements spatially distributed over the country and with in-situ measurements concentrated in on small area. For country level a number of 20 stations from the national meteorological observations network in Romania were selected. These stations have in-situ measurements for soil moisture in the first 5 cm of the soil surface. The stations are more or less distributed in one pixel of SMOS, but it has the advantage that covers almost all the country with a wide range of environmental conditions. Additionally 10 mobile soil moisture measurements stations were acquired and installed. These are spatially concentrated in one SMOS pixel in order to have a more detailed validation against the soil type, soil texture, land surface temperature and vegetation type inside one pixel. The results were compared and analyzed for each day, week, season, soil type, and soil texture and vegetation type. Minimum, maximum, mean and standard deviation were extracted and analyzed for each validation criteria and a hierarchy of those were performed. An upscaling method based on the relations between soil moisture, land surface temperature and vegetation indices was tested and implemented. The study was financed by the Romanian Space Agency within the framework of ASSIMO project http://assimo.meteoromania.ro.

  10. Satellite Driven Estimation of Primary Productivity of Agroecosystems in India

    Science.gov (United States)

    Patel, N. R.; Dadhwal, V. K.; Agrawal, S.; Saha, S. K.

    2011-08-01

    Earth observation driven ecosystem modeling have played a major role in estimation of carbon budget components such as gross primary productivity (GPP) and net primary production (NPP) over terrestrial ecosystems, including agriculture. The present study therefore evaluate satellite-driven vegetation photosynthesis (VPM) model for GPP estimation over agro-ecosystems in India by using time series of the Normalized Difference Vegetation Index (NDVI) from SPOT-VEGETATION, cloud cover observation from MODIS, coarse-grid C3/C4 crop fraction and decadal grided databases of maximum and minimum temperatures. Parameterization of VPM parameters e.g. maximum light use efficiency (ɛ*) and Tscalar was done based on eddy-covariance measurements and literature survey. Incorporation of C3/C4 crop fraction is a modification to commonly used constant maximum LUE. Modeling results from VPM captured very well the geographical pattern of GPP and NPP over cropland in India. Well managed agro-ecosystems in Trans-Gangetic and upper Indo-Gangetic plains had the highest magnitude of GPP with peak GPP during kharif occurs in sugarcane-wheat system (western UP) and it occurs in rice-wheat system (Punjab) during Rabi season. Overall, croplands in these plains had more annual GPP (> 1000 g C m-2) and NPP (> 600 g C m-2) due to input-intensive cultivation. Desertic tracts of western Rajasthan showed the least GPP and NPP values. Country-level contribution of croplands to national GPP and NPP amounts to1.34 Pg C year-1 and 0.859 Pg C year-1, respectively. Modeled estimates of cropland NPP agrees well with ground-based estimates for north-western India (R2 = 0.63 and RMSE = 108 g C m-2). Future research will focus on evaluating the VPM model with medium resolution sensors such as AWiFS and MODIS for rice-wheat system and validating with eddy-covariance measurements.

  11. UAH Version 6 global satellite temperature products: Methodology and results

    Science.gov (United States)

    Spencer, Roy W.; Christy, John R.; Braswell, William D.

    2017-02-01

    Version 6 of the UAH MSU/AMSU global satellite temperature dataset represents an extensive revision of the procedures employed in previous versions of the UAH datasets. The two most significant results from an end-user perspective are (1) a decrease in the global-average lower tropospheric temperature (LT) trend from +0.14°C decade-1 to +0.11°C decade-1 (Jan. 1979 through Dec. 2015); and (2) the geographic distribution of the LT trends, including higher spatial resolution, owing to a new method for computing LT. We describe the major changes in processing strategy, including a new method for monthly gridpoint averaging which uses all of the footprint data yet eliminates the need for limb correction; a new multi-channel (rather than multi-angle) method for computing the lower tropospheric (LT) temperature product which requires an additional tropopause (TP) channel to be used; and a new empirical method for diurnal drift correction. We show results for LT, the midtroposphere (MT, from MSU2/AMSU5), and lower stratosphere (LS, from MSU4/AMSU9). A 0.03°C decade-1 reduction in the global LT trend from the Version 5.6 product is partly due to lesser sensitivity of the new LT to land surface skin temperature (est. 0.01°C decade-1), with the remainder of the reduction (0.02°C decade-1) due to the new diurnal drift adjustment, the more robust method of LT calculation, and other changes in processing procedures.

  12. SATELLITE DRIVEN ESTIMATION OF PRIMARY PRODUCTIVITY OF AGROECOSYSTEMS IN INDIA

    Directory of Open Access Journals (Sweden)

    N. R. Patel

    2012-08-01

    Full Text Available Earth observation driven ecosystem modeling have played a major role in estimation of carbon budget components such as gross primary productivity (GPP and net primary production (NPP over terrestrial ecosystems, including agriculture. The present study therefore evaluate satellite-driven vegetation photosynthesis (VPM model for GPP estimation over agro-ecosystems in India by using time series of the Normalized Difference Vegetation Index (NDVI from SPOT-VEGETATION, cloud cover observation from MODIS, coarse-grid C3/C4 crop fraction and decadal grided databases of maximum and minimum temperatures. Parameterization of VPM parameters e.g. maximum light use efficiency (ε* and Tscalar was done based on eddy-covariance measurements and literature survey. Incorporation of C3/C4 crop fraction is a modification to commonly used constant maximum LUE. Modeling results from VPM captured very well the geographical pattern of GPP and NPP over cropland in India. Well managed agro-ecosystems in Trans-Gangetic and upper Indo-Gangetic plains had the highest magnitude of GPP with peak GPP during kharif occurs in sugarcane-wheat system (western UP and it occurs in rice-wheat system (Punjab during Rabi season. Overall, croplands in these plains had more annual GPP (> 1000 g C m-2 and NPP (> 600 g C m-2 due to input-intensive cultivation. Desertic tracts of western Rajasthan showed the least GPP and NPP values. Country-level contribution of croplands to national GPP and NPP amounts to1.34 Pg C year-1 and 0.859 Pg C year-1, respectively. Modeled estimates of cropland NPP agrees well with ground-based estimates for north-western India (R2 = 0.63 and RMSE = 108 g C m-2. Future research will focus on evaluating the VPM model with medium resolution sensors such as AWiFS and MODIS for rice-wheat system and validating with eddy-covariance measurements.

  13. Quantifying Uncertainty of Wind Power Production Through an Analog Ensemble

    Science.gov (United States)

    Shahriari, M.; Cervone, G.

    2016-12-01

    The Analog Ensemble (AnEn) method is used to generate probabilistic weather forecasts that quantify the uncertainty in power estimates at hypothetical wind farm locations. The data are from the NREL Eastern Wind Dataset that includes more than 1,300 modeled wind farms. The AnEn model uses a two-dimensional grid to estimate the probability distribution of wind speed (the predictand) given the values of predictor variables such as temperature, pressure, geopotential height, U-component and V-component of wind. The meteorological data is taken from the NCEP GFS which is available on a 0.25 degree grid resolution. The methodology first divides the data into two classes: training period and verification period. The AnEn selects a point in the verification period and searches for the best matching estimates (analogs) in the training period. The predictand value at those analogs are the ensemble prediction for the point in the verification period. The model provides a grid of wind speed values and the uncertainty (probability index) associated with each estimate. Each wind farm is associated with a probability index which quantifies the degree of difficulty to estimate wind power. Further, the uncertainty in estimation is related to other factors such as topography, land cover and wind resources. This is achieved by using a GIS system to compute the correlation between the probability index and geographical characteristics. This study has significant applications for investors in renewable energy sector especially wind farm developers. Lower level of uncertainty facilitates the process of submitting bids into day ahead and real time electricity markets. Thus, building wind farms in regions with lower levels of uncertainty will reduce the real-time operational risks and create a hedge against volatile real-time prices. Further, the links between wind estimate uncertainty and factors such as topography and wind resources, provide wind farm developers with valuable

  14. Hydrogen Gas Production in a Stand-Alone Wind Farm

    Directory of Open Access Journals (Sweden)

    M. Naziry Kordkandy

    2017-04-01

    Full Text Available This paper is analyzing the operation of a stand-alone wind farm with variable speed turbines, permanent magnet synchronous generators (PMSG and a system for converting wind energy during wind speed variations. On this paper, the design and modeling of a wind system which uses PMSG’s to provide the required power of a hydrogen gas electrolyzer system, is discussed. This wind farm consists of three wind turbines, boost DC-DC converters, diode full bridge rectifiers, permanent magnet synchronous generators, MPPT control and a hydrogen gas electrolyzer system. The MPPT controller based on fuzzy logic is designed to adjust the duty ratio of the boost DC-DC converters to absorb maximum power. The proposed fuzzy logic controller assimilates, with (PSF MPPT algorithm which generally used to absorb maximum power from paralleled wind turbines and stores it in form of hydrogen gas. The system is modeled and its behavior is studied using the MATLAB software.

  15. Using satellite data in map design and production

    Science.gov (United States)

    Hutchinson, John A.

    2002-01-01

    Satellite image maps have been produced by the U.S. Geological Survey (USGS) since shortly after the launch of the first Landsat satellite in 1972. Over the years, the use of image data to design and produce maps has developed from a manual and photographic process to one that incorporates geographic information systems, desktop publishing, and digital prepress techniques. At the same time, the content of most image-based maps produced by the USGS has shifted from raw image data to land cover or other information layers derived from satellite imagery, often portrayed in combination with shaded relief.

  16. Wake interaction and power production of variable height model wind farms

    DEFF Research Database (Denmark)

    Vested, Malene Hovgaard; Hamilton, N.; Sørensen, Jens Nørkær;

    2014-01-01

    of comparison. It was found that downstream of the exit row wind turbine, the power was increased by 25% in the case of a staggered height configuration. This is partly due to the fact that the taller turbines reach into a flow area with a softened velocity gradient. Another aspect is that the wake downstream......Understanding wake dynamics is an ongoing research topic in wind energy, since wakes have considerable effects on the power production when wind turbines are placed in a wind farm. Wind tunnel experiments have been conducted to study the wake to wake interaction in a model wind farm in tandem...... with measurements of the extracted power. The aim is to investigate how alternating mast height influences the interaction of the wakes and the power production. Via the use of stereo-particle image velocimetry, the flow field was obtained in the first and last rows of the wind turbine array as a basis...

  17. Comparison of different methods for evaluation of wind turbine power production based on wind measurements

    Directory of Open Access Journals (Sweden)

    Bezrukovs Valerijs

    2016-01-01

    Full Text Available Investigations of the wind shear up to the height of 200 (m on the Latvian coast of the Baltic Sea have been carried out using a Pentalum SpiDAR laser measuring complex. Based on wind speeds measurements for three levels – 30, 40 and 50 (m, assessment of the operational efficiency of the wind turbines for heights 100, 140 and 180 (m have been performed. For comparison, this analysis involves five different approaches: the Rayleigh frequency distribution, three different Weibull frequency distributions and method based on approximation of the cubic wind speed. Results are compared with measurements on the corresponding heights.

  18. Potentials of satellite imagery for monitoring arctic goose productivity

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This paper reports upon the exciting possibility that satellite imagery may now provide feasible means for grossly monitoring arctic habitat conditions in a timely...

  19. Satellite tracking of harbour seals on Horns Reef - Use of the Horns Reef wind farm area and the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Tougaard, J.; Tougaard, S.; Jensen, Thyge [Fisheries and Maritime Museum Esbjerg (Denmark); Ebbesen, I. [Univ. of Sourthern Denmark, Inst. of Biology, Odense (Denmark); Teilmann, J. [NationL Environmental Res. Inst., Roskidle (Denmark)

    2003-03-15

    Ten harbour seals (Phoca vitulina) caught on the Danish Wadden Sea island Roemoe were equipped with satellite linked time depth recorders. The animals were caught on three separate occasions (Jan. 4th, Feb. 18th and May 6th, 2002). The transmitters worked between 49 and 100 days, relaying positional and dive information back via the ARGOS satellite service until beginning of July. Background for the studies is the construction of the Worlds largest off shore wind farm on Horns Reef. Based on previous studies using VHF-transmitters, it was expected that the seals would spend considerable time on Horns Reef. The VHF-telemetry studies showed that the preferred direction for seals leaving the Danish Wadden Sea is NW from Graedyb tidal area outside Esbjerg, the direction directly towards the wind farm area. The previously used VHF-transmitters had a limited detection range and it was decided to equip a number of seals from the same area as before with satellite transmitters. This allows for positioning of the seals in the entire North Sea as well as providing dive summary information, as a transmitter with a depth transducer was chosen for the study. Positional information revealed that animals move about more extensively than previously believed. Substantial variation between animals was observed and each seal seemed to have adopted its own foraging strategy. Some animals travelled to the centre of the North Sea on foraging trips and spent considerable time close to the bottom at 30-70 meters depth. Other seals remained in the German Bight and yet others spent considerable time on and around Horns Reef. The area of Horns reef wind farm constitutes a negligible fraction of the total area visited by the tagged seals. The reef as a whole however, appears to be important to the seals both for foraging and as transit area to other feeding grounds further off shore. The resolution in positional information is not sufficiently high to allow for a detailed study of the effects

  20. Backup Communication Routing Through Internet Satellite, WINDS for Transmitting of Disaster Relief Data

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2011-09-01

    Full Text Available A countermeasure for round trip delay which occurs in between satellite and ground with network accelerator is investigated together with operating system dependency on effectiveness of accelerator. Also disaster relief data transmission experiments are conducted for mitigation of disaster together with acceleration of disaster related data transmission between local government and disaster prevention center. Disaster relief information including remote sensing satellite images and information from the disaster occurred areas to local government for creation of evacuation information is accelerated so that it becomes possible to send them to the residents in the suffered areas due to disaster through data broadcasting in the digital TV channel.

  1. Offshore Wind Power Production in Critical Weather Conditions

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Sørensen, Poul Ejnar

    2012-01-01

    Critical weather conditions, i.e. extreme winds will raise a lot of challenges when it comes to the secure operation of the whole European electric system with the future large scale offshore wind power. This is especially true for Denmark where the target is that wind power should provide 50% of...... and quantifying the balancing reserve requirements needed in order to keep the security of the power system....

  2. UTILIZATION OF WIND POWER IN RWANDA : Design and Production Option

    OpenAIRE

    Eric, MANIRAGUHA

    2013-01-01

    This Master Thesis is the research done in the country of Rwanda. The project leads to study the climate of this country in order to establish whether this climate could be used to produce energy from air and to implement the first wind turbine for serving the nation.   After an introduction about the historical background of wind power, the thesis work deals with assessment of wind energy potential of Rwanda in focusing of the most suitable place for wind power plants. The best location with...

  3. Scientific opportunities using satellite surface wind stress measurements over the ocean

    Science.gov (United States)

    1982-01-01

    Scientific opportunities that would be possible with the ability to collect wind data from space are highlighted. Minimum requirements for the space platform and ground data reduction system are assessed. The operational uses that may develop in government and commercial applications of these data are reviewed. The opportunity to predict the large-scale ocean anomaly called El Nino is highlighted.

  4. Reliability measures for indexed semi-Markov chains applied to wind energy production

    CERN Document Server

    D'Amico, Guglielmo; Prattico, Flavio

    2013-01-01

    The computation of the dependability measures is a crucial point in the planning and development of a wind farm. In this paper we address the issue of energy production by wind turbine by using an indexed semi-Markov chain as a model of wind speed. We present the mathematical model, we describe the data and technical characteristics of a commercial wind turbine (Aircon HAWT-10kW). We show how to compute some of the main dependability measures such as reliability, availability and maintainability functions. We compare the results of the model with real energy production obtained from data available in the Lastem station (Italy) and sampled every 10 minutes.

  5. Low-frequency variations in primary production in the Oman upwelling zone associated with monsoon winds

    Institute of Scientific and Technical Information of China (English)

    LIAO Xiaomei; ZHAN Haigang; WEI Xing

    2012-01-01

    Thirteen-year satellite-derived data are used to investigate the temporal variability of net primaryproduction (NPP) in the Oman upwelling zone and its potential forcing mechanisms.The NPP in the Oman upwelling zone is characterized by an abnormal decrease during El Ni(n)o events.Such an NPP decrease may be related to El Ni(n)o-driven anomalous summertime weak wind.During the summer following El Ni(n)o,the anomalous northeasterly wind forced by southwest Indian Ocean warming weakens the southwest monsoon and warms the Arabian Sea.The abnormal wind weakens the coastal Ekman transport,offshore Ekman pumping and horizontal advection,resulting in reduced upward nutrient supply to the euphotic zone.A slightly declining trend in NPP after 2000 associated with a gradual decrease in surface monsoon winds is discussed.

  6. A dynamic approach for evaluating coarse scale satellite soil moisture products

    Directory of Open Access Journals (Sweden)

    A. Loew

    2010-09-01

    Full Text Available Validating coarse scale remote sensing soil moisture products requires a comparison of gridded data to point-like ground measurements. The necessary aggregation of in situ measurements to the footprint scale of a satellite sensor (>100 km2 introduces uncertainties in the validation of the satellite soil moisture product. Observed differences between the satellite product and in situ data are therefore partly attributable to these aggregation uncertainties. The present paper investigates different approaches to disentangle the error of the satellite product from the uncertainties associated to the up-scaling of the reference data. A novel approach is proposed, which allows for the quantification of the remote sensing soil moisture error using a temporally adaptive technique. It is shown that the point-to-area sampling error can be estimated within 0.0084 [m3/m3].

  7. Exploration of satellite-derived data products for atmospheric turbulence studies

    CSIR Research Space (South Africa)

    Griffith, DJ

    2014-09-01

    Full Text Available layer. This has included all satellite data products that are relevant to the surface energy balance such as surface reflectance, temperature and emissivity. It was also important to identify active archive data services that can provide preprocessed...

  8. Polynomial chaos for the computation of annual energy production in wind farm layout optimization

    Science.gov (United States)

    Padrón, A. S.; Stanley, A. P. J.; Thomas, J. J.; Alonso, J. J.; Ning, A.

    2016-09-01

    Careful management of wake interference is essential to further improve Annual Energy Production (AEP) of wind farms. Wake effects can be minimized through optimization of turbine layout, wind farm control, and turbine design. Realistic wind farm optimization is challenging because it has numerous design degrees of freedom and must account for the stochastic nature of wind. In this paper we provide a framework for calculating AEP for any relevant uncertain (stochastic) variable of interest. We use Polynomial Chaos (PC) to efficiently quantify the effect of the stochastic variables—wind direction and wind speed—on the statistical outputs of interest (AEP) for wind farm layout optimization. When the stochastic variable includes the wind direction, polynomial chaos is one order of magnitude more accurate in computing the AEP when compared to commonly used simplistic integration techniques (rectangle rule), especially for non grid-like wind farm layouts. Furthermore, PC requires less simulations for the same accuracy. This allows for more efficient optimization and uncertainty quantification of wind farm energy production.

  9. The Impacts of Satellite Remotely Sensed Winds and Total Precipitable Vapour in WRF Tropical Cyclone Track Forecasts

    Directory of Open Access Journals (Sweden)

    Diandong Ren

    2016-01-01

    Full Text Available This study assesses the impact assimilating the scatterometer near-surface wind observations and total precipitable water from the SSMI, into WRF on genesis and track forecasting of four tropical cyclones (TCs. These TCs are selected to be representative of different intensity categories and basins. Impact is via a series of data denial experiments that systematically exclude the remote sensed information. Compared with the control case, in which only the final analysis atmospheric variables are used to initialize and provide the lateral boundary conditions, the data assimilation runs performed consistently better, but with very different skill levels for the different TCs. Eliassen-Palm flux analyses are employed. It is confirmed that if a polar orbital satellite footprint passes over the TC’s critical genesis region, the forecast will profit most from assimilating the remotely sensed information. If the critical genesis region lies within an interorbital gap then, regardless of how strong the TC later becomes (e.g., Katrina 2005, the improvement from assimilating near-surface winds and total precipitable water in the model prediction is severely limited. This underpins the need for a synergy of data from different scatterometers/radiometers. Other approaches are suggested to improve the accuracy in the prediction of TC genesis and tracks.

  10. Level-2 product generation for the Swarm satellite constellation mission

    DEFF Research Database (Denmark)

    Olsen, Poul Erik Holmdahl; Tøffner-Clausen, Lars; Olsen, Nils

    In order to take advantage of the unique constellation aspect of ESA's Swarm constellation mission, considerably advanced data analysis tools have been developed. The Swarm ESL/SCARF (Satellite Constellation Application and Research Facility), a consortium of several research institutions, derives...

  11. Level-2 product generation for the Swarm satellite constellation mission

    DEFF Research Database (Denmark)

    Olsen, Poul Erik Holmdahl; Tøffner-Clausen, Lars; Olsen, Nils

    In order to take advantage of the unique constellation aspect of ESA's Swarm constellation mission, considerably advanced data analysis tools have been developed. The Swarm ESL/SCARF (Satellite Constellation Application and Research Facility), a consortium of several research institutions, derives...

  12. Stochastic modeling and performance monitoring of wind farm power production

    CERN Document Server

    Milan, Patrick; Peinke, Joachim

    2015-01-01

    We present a new stochastic approach to describe and remodel the conversion process of a wind farm at a sampling frequency of 1Hz. When conditioning on various wind direction sectors, the dynamics of the conversion process appear as a fluctuating trajectory around an average IEC-like power curve, see section II. Our approach is to consider the wind farm as a dynamical system that can be described as a stochastic drift/diffusion model, where a drift coefficient describes the attraction towards the power curve and a diffusion coefficient quantifies additional turbulent fluctuations. These stochastic coefficients are inserted into a Langevin equation that, once properly adapted to our particular system, models a synthetic signal of power output for any given wind speed/direction signals, see section III. When combined with a pre-model for turbulent wind fluctuations, the stochastic approach models the power output of the wind farm at a sampling frequency of 1Hz using only ten-minute average values of wind speed ...

  13. Site-level evaluation of satellite-based global terrestrial gross primary production and net primary production monitoring.

    Science.gov (United States)

    David P. Turner; William D. Ritts; Warren B. Cohen; Thomas K. Maeirsperger; Stith T. Gower; Al A. Kirschbaum; Steve W. Runnings; Maosheng Zhaos; Steven C. Wofsy; Allison L. Dunn; Beverly E. Law; John L. Campbell; Walter C. Oechel; Hyo Jung Kwon; Tilden P. Meyers; Eric E. Small; Shirley A. Kurc; John A. Gamon

    2005-01-01

    Operational monitoring of global terrestrial gross primary production (GPP) and net primary production (NPP) is now underway using imagery from the satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Evaluation of MODIS GPP and NPP products will require site-level studies across a range of biomes, with close attention to numerous scaling...

  14. Optimal construction and combined wind and diesel power production in a regional power purchase

    Energy Technology Data Exchange (ETDEWEB)

    Lautala, P.; Antila, H.; Raekkoelaeinen, J.; Heikkilae, H. [Tampere Univ. of Technology (Finland). Automation and Control Inst.

    1998-12-31

    A weak electricity transmission and distribution network and a wind generator were modelled by a non-linear dynamic model. Energy purchase of a small utility was modelled as a linear mixed integer optimisation problem. The dynamic model was used to simulate the effects of distance between the wind generator and a regional power grid and the effects of changes in the production of the wind generator. The optimisation model was used to investigate the effect of the combined diesel and wind production. In this case the results show that if the distance between the generator and the network grid is more than 70 km, then voltage fluctuations exceed acceptable levels. The optimisation provides the value of the combined diesel and wind production. (orig.)

  15. Non-ideal feedforward torque control of wind turbines: Impacts on annual energy production & gross earnings

    Science.gov (United States)

    Hackl, Christoph; Schechner, Korbinian

    2016-09-01

    We discuss non-ideal torque control in wind turbine systems. Most high-level controllers generate a reference torque which is then send to the underlying electrical drive system (generator+inverter) of the wind turbine system to steer the turbine/generator to its optimal operation point (depending on the wind speed). The energy production heavily depends on the mechanical power (i.e. the product of rotational speed and generator torque). However, since torque sensors in the MW range are not available or extremely expensive, the underlying torque control system is implemented as feedforward control and, therefore, is inherently sensitive to parameter variations/uncertainties. Based on real wind data and a wind turbine system model, we discuss causes and impacts of non-ideal feedforward torque control on the energy production and the annual gross earnings.

  16. Combined Production Of A Full-Scale Wave Converter And A Full-Scale Wind Turbine

    DEFF Research Database (Denmark)

    Chozas, Julia Fernandez; Kramer, Morten; Sørensen, H.C.

    2012-01-01

    correlation between winds and waves, characterised by an average delay of 2 to 3 hours. Up to 9hours-delay the correlation remains high. Regarding power productions, results show every portfolio combining wave and wind technologies provides important benefits: minimises the percentage of time of zero...

  17. Combined Production Of A Full-Scale Wave Converter And A Full-Scale Wind Turbine

    DEFF Research Database (Denmark)

    Chozas, Julia Fernandez; Kramer, Morten; Sørensen, H.C.

    2012-01-01

    correlation between winds and waves, characterised by an average delay of 2 to 3 hours. Up to 9hours-delay the correlation remains high. Regarding power productions, results show every portfolio combining wave and wind technologies provides important benefits: minimises the percentage of time of zero...

  18. TropFlux wind stresses over the tropical oceans: Evaluation and comparison with other products

    Digital Repository Service at National Institute of Oceanography (India)

    PraveenKumar, B.; Vialard, J.; Lengaigne, M.; Murty, V.S.N.; McPhaden, M.J.; Cronin, M.F.; Pinsard, F.; Reddy, K.G.

    We present TropFlux wind stresses and evaluate them against observations along with other widely used daily air-sea momentum flux products (NCEP, NCEP2, ERA-I and QuikSCAT). TropFlux wind stresses are computed from the COARE v3.0 algorithm, using...

  19. Operational high latitude surface irradiance products from polar orbiting satellites

    Science.gov (United States)

    Godøy, Øystein

    2016-12-01

    It remains a challenge to find an adequate approach for operational estimation of surface incoming short- and longwave irradiance at high latitudes using polar orbiting meteorological satellite data. In this presentation validation results at a number of North Atlantic and Arctic Ocean high latitude stations are presented and discussed. The validation results have revealed that although the method works well and normally fulfil the operational requirements, there is room for improvement. A number of issues that can improve the estimates at high latitudes have been identified. These improvements are partly related to improved cloud classification using satellite data and partly related to improved handling of multiple reflections over bright surfaces (snow and sea ice), especially in broken cloud conditions. Furthermore, the availability of validation sites over open ocean and sea ice is a challenge.

  20. Supply Chain Management of Satellite Mechanisms- Product Development and Monitoring

    OpenAIRE

    Sreejith; Vishnu G Nair

    2014-01-01

    The project report primary deals with the Testing, Analysis, Modeling of the components of the Solar Array deployment Mechanism and a preliminary design. It also discusses the Monitoring of the supply chain management system for the procurement of the components from vendors. The deployment of solar array or any other appendage is a mission critical activity of any satellite. It is necessary to study about the deployment mechanism because once the array latches up, the satelli...

  1. Calculating Wind Farm Production in Al-Shihabi (South Of Iraq Using WASP

    Directory of Open Access Journals (Sweden)

    Amani I.Al-Tmimi

    2016-08-01

    Full Text Available The Wind Turbine farms are becoming popular in the renewable energy world. In this research, the Wind Atlas Analysis and Application Program (WAsP has been used to estimate wind power density in Al-Shihabi (south of Iraq. All statistical operations on data series are obtained from Field data collected from the wind measurement towers which installed by the Science and Technology Ministry at Kut city south of IRAQ at three heights (10, 30, 50 m. The wind turbine selected for this study to be installed in the wind farm are Bonus- 300kw, 600kw The Annual Energy Production (AEP has been calculate which varies between (746.990 - 759.446 MWH at 30 m and it s varies between produced AEP (1.576 - 1.600 GWh at 50 m ,this site classified as ( class-1.

  2. Sensitivity of Distributed Hydrologic Simulations to Ground and Satellite Based Rainfall Products

    Directory of Open Access Journals (Sweden)

    Singaiah Chintalapudi

    2014-05-01

    Full Text Available In this study, seven precipitation products (rain gauges, NEXRAD MPE, PERSIANN 0.25 degree, PERSIANN CCS-3hr, PERSIANN CCS-1hr, TRMM 3B42V7, and CMORPH were used to force a physically-based distributed hydrologic model. The model was driven by these products to simulate the hydrologic response of a 1232 km2 watershed in the Guadalupe River basin, Texas. Storm events in 2007 were used to analyze the precipitation products. Comparison with rain gauge observations reveals that there were significant biases in the satellite rainfall products and large variations in the estimated amounts. The radar basin average precipitation compared very well with the rain gauge product while the gauge-adjusted TRMM 3B42V7 precipitation compared best with observed rainfall among all satellite precipitation products. The NEXRAD MPE simulated streamflows matched the observed ones the best yielding the highest Nash-Sutcliffe Efficiency correlation coefficient values for both the July and August 2007 events. Simulations driven by TRMM 3B42V7 matched the observed streamflow better than other satellite products for both events. The PERSIANN coarse resolution product yielded better runoff results than the higher resolution product. The study reveals that satellite rainfall products are viable alternatives when rain gauge or ground radar observations are sparse or non-existent.

  3. ASSESSMENT OF A WIND TURBINE INTELLIGENT CONTROLLER FOR ENHANCED ENERGY PRODUCTION AND POLLUTION REDUCTION

    Science.gov (United States)

    This study assessed the enhanced energy production which is possible when variable-speed wind turbines are electronically controlled by an intelligent controller for efficiency optimization and performance improvement. The control system consists of three fuzzy- logic controllers...

  4. Improvement of Wind Energy Production through HVDC Systems

    Directory of Open Access Journals (Sweden)

    Morris Brenna

    2017-01-01

    Full Text Available Variable and non-programmable resources, such as solar and wind, have undergone a stunning growth in recent years and are likely to gain even more importance in the future. Their strong presence in the national electricity mix has created issues in many countries regarding the secure operation of the power system. In order to guarantee the stability of the system, several TSOs have resorted to wind energy curtailment, which represents a waste of clean energy and an economic loss. In order to analyze this issue, a model of the Italian power system was developed, a program able to simulate the electricity dispatching mechanism. The model was, then, used to evaluate possible solutions to reduce wind curtailment. In particular, a proposal for the construction of an HVDC line linking Southern and Northern Italy was studied.

  5. Boosting the Power Generation in Wind and Hydro Power Production

    OpenAIRE

    2016-01-01

    When approaching a conventional wind turbine, the air flow is slowed down and widened. This results in a loss of turbine efficiency. In order to exploit wind or water flow power as effectively as possible, it was suggested that the turbine should be placed inside a shroud, which consists of 4 wing-shaped surfaces. Two internal air foils improve the turbine performance by speeding up the flow acting on the turbine blades, two external wings create a field of low pressure behind the turbine, th...

  6. Comparison of ground based indices (API and AQI) with satellite based aerosol products.

    Science.gov (United States)

    Zheng, Sheng; Cao, Chun-Xiang; Singh, Ramesh P

    2014-08-01

    Air quality in mega cities is one of the major concerns due to serious health issues and its indirect impact to the climate. Among mega cities, Beijing city is considered as one of the densely populated cities with extremely poor air quality. The meteorological parameters (wind, surface temperature, air temperature and relative humidity) control the dynamics and dispersion of air pollution. China National Environmental Monitoring Centre (CNEMC) started air pollution index (API) as of 2000 to evaluate air quality, but over the years, it was felt that the air quality is not well represented by API. Recently, the Ministry of Environmental Protection (MEP) of the People's Republic of China (PRC) started using a new index "air quality index (AQI)" from January 2013. We have compared API and AQI with three different MODIS (MODIS - Moderate Resolution Imaging SpectroRadiometer, onboard the Terra/Aqua satellites) AOD (aerosol optical depth) products for ten months, January-October, 2013. The correlation between AQI and Aqua Deep Blue AOD was found to be reasonably good as compared with API, mainly due to inclusion of PM2.5 in the calculation of AQI. In addition, for every month, the correlation coefficient between AQI and Aqua Deep Blue AOD was found to be relatively higher in the month of February to May. According to the monthly average distribution of precipitation, temperature, and PM10, the air quality in the months of June-September was better as compared to those in the months of February-May. AQI and Aqua Deep Blue AOD show highly polluted days associated with dust event, representing true air quality of Beijing.

  7. Net sea–air CO2 flux uncertainties in the Bay of Biscay based on the choice of wind speed products and gas transfer parameterizations

    Directory of Open Access Journals (Sweden)

    P. Otero

    2013-05-01

    Full Text Available The estimation of sea–air CO2 fluxes is largely dependent on wind speed through the gas transfer velocity parameterization. In this paper, we quantify uncertainties in the estimation of the CO2 uptake in the Bay of Biscay resulting from the use of different sources of wind speed such as three different global reanalysis meteorological models (NCEP/NCAR 1, NCEP/DOE 2 and ERA-Interim, one high-resolution regional forecast model (HIRLAM-AEMet, winds derived under the Cross-Calibrated Multi-Platform (CCMP project, and QuikSCAT winds in combination with some of the most widely used gas transfer velocity parameterizations. Results show that net CO2 flux estimations during an entire seasonal cycle (September 2002–September 2003 may vary by a factor of ~ 3 depending on the selected wind speed product and the gas exchange parameterization, with the highest impact due to the last one. The comparison of satellite- and model-derived winds with observations at buoys advises against the systematic overestimation of NCEP-2 and the underestimation of NCEP-1. In the coastal region, the presence of land and the time resolution are the main constraints of QuikSCAT, which turns CCMP and ERA-Interim in the preferred options.

  8. Web-Based Satellite Products Database for Meteorological and Climate Applications

    Science.gov (United States)

    Phan, Dung; Spangenberg, Douglas A.; Palikonda, Rabindra; Khaiyer, Mandana M.; Nordeen, Michele L.; Nguyen, Louis; Minnis, Patrick

    2004-01-01

    The need for ready access to satellite data and associated physical parameters such as cloud properties has been steadily growing. Air traffic management, weather forecasters, energy producers, and weather and climate researchers among others can utilize more satellite information than in the past. Thus, it is essential that such data are made available in near real-time and as archival products in an easy-access and user friendly environment. A host of Internet web sites currently provide a variety of satellite products for various applications. Each site has a unique contribution with appeal to a particular segment of the public and scientific community. This is no less true for the NASA Langley's Clouds and Radiation (NLCR) website (http://www-pm.larc.nasa.gov) that has been evolving over the past 10 years to support a variety of research projects This website was originally developed to display cloud products derived from the Geostationary Operational Environmental Satellite (GOES) over the Southern Great Plains for the Atmospheric Radiation Measurement (ARM) Program. It has evolved into a site providing a comprehensive database of near real-time and historical satellite products used for meteorological, aviation, and climate studies. To encourage the user community to take advantage of the site, this paper summarizes the various products and projects supported by the website and discusses future options for new datasets.

  9. Analysis of Characteristics of QZSS Satellite Orbit and Clock Products during Yaw Attitude Model Switching

    Directory of Open Access Journals (Sweden)

    ZHOU Peiyuan

    2016-03-01

    Full Text Available Yaw attitude model switching of navigation satellites have great impact on its orbit and clock products derived from precise orbit determination. Firstly, the yaw attitude and solar radiation model of QZSS is given briefly. Then, using QZSS precise orbit and clock products provided by IGS MGEX analysis center, precision of orbit and clock is analyzed by satellite laser ranging residuals and polynomial fit residuals respectively. Finally, spectral analysis and modified Allan variance is carried out on clock products to reveal its periodic variations. Research on QZSS satellite orbit and clock products of 2014 shows that there are two eclipse seasons of 20 days and the beta angle is fluctuating with a period of half-year. And there is significant correlation between the precision of orbit and clock products and beta angle. Moreover, the satellite clock offset has periodic variations similar to orbit periods and its amplitude is changing with the beta angle which indicates problems of current orbit determination strategies. In view of similarities between QZSS and BeiDou IGSO and MEO satellites in yaw attitude model, the conclusion is beneficial to improve BeiDou precise orbit determination.

  10. Evaluation of multi-satellite rainfall products over India during monsoon

    Science.gov (United States)

    Mitra, Ashis K.; Prakash, Satya; Pai, D. S.; Srivastava, A. K.

    2016-05-01

    Simulation and prediction of Indian monsoon rainfall at scales from days-to-season is a challenging task for numerical modelling community worldwide. Gridded estimates of daily rainfall data are required for both land and oceanic regions for model validation, process studies and in turn for model development. Due to recent developments in satellite meteorology, it has become possible to produce realistic near real-time gridded rainfall datasets at operational basis by combining satellite estimates with rain gauge values and other available in-situ observations. Microwave and space based radar based estimates of rainfall has revolutionised the preparation of rainfall datasets especially for tropics. However, a variety of multi-satellite products are available over Indian monsoon region from a variety of sources. Popular products like TRMM TMPA3B42 (RT and V7), GsMaP, CPC/RFE, GPCP and GPM are available to end users in various space/time scales for applications and model validation. In this study, we show the representation and skill of monsoon rainfall from a variety of multi-satellite products over the Indian region. The bias and skill of multi-satellite rainfall are evaluated against gauge based observations. It was found that the TRMM based TMPA was one of the best dataset for Indian monsoon region. Attempt is made to compare the latest GPM based data with other products. The GPM based rainfall product is seen to be superior compared to TRMM.

  11. Estimation of land remote sensing satellites productivity based on the simulation technique

    Science.gov (United States)

    Kurenkov, Vladimir I.; Kucherov, Alexander S.; Yakischik, Artem A.

    2017-01-01

    The problem of estimating land remote sensing satellites productivity is considered. Here, productivity is treated as a number of separate survey objects taken in a definite time. Appropriate mathematical models have been developed. Some results obtained with the help of the software worked out in Delphi programming support environment are presented.

  12. Fault tolerant wind turbine production operation and shutdown (Sustainable Control)

    NARCIS (Netherlands)

    Van Engelen, T.; Schuurmans, J.; Kanev, S.; Dong, J.; Verhaegen, M.H.G.; Hayashi, Y.

    2011-01-01

    Extreme environmental conditions as well as system failure are real-life phenomena. Especially offshore, extreme environmental conditions and system faults are to be dealt with in an effective way. The project Sustainable Control, a new approach to operate wind turbines (Agentschap NL, grant EOSLT02

  13. Variable Speed Wind Turbines Capability for Temporary Over-Production

    DEFF Research Database (Denmark)

    Tarnowski, Germán Claudio; Kjær, Philip Carne; Sørensen, Poul Ejnar

    2009-01-01

    New control systems for Variable Speed Wind Turbines (VSWT) need to be developed in order to provide inertia response and frequency control to support the grid. This work studies the behavior and capability of VSWT for providing temporary active power overproduction. The study is conducted on a m...

  14. Wind farm production cost: Optimum turbine size and farm capacity in the actual market

    Energy Technology Data Exchange (ETDEWEB)

    Laali, A.R.; Meyer, J.L.; Bellot, C. [Electricite de France, Chatou (France); Louche, A. [Espace de Recherche, Ajaccio (France)

    1996-12-31

    Several studies are undertaken in R&D Division of EDF in collaboration with ERASME association in order to have a good knowledge of the wind energy production costs. These studies are performed in the framework of a wind energy monitoring project and concern the influence of a few parameters like wind farm capacity, turbine size and wind speed on production costs, through an analysis of the actual market trend. Some 50 manufacturers and 140 different kind of wind turbines are considered for this study. The minimum production cost is situated at 800/900 kW wind turbine rated power. This point will probably move to more important powers in the future. This study is valid only for average conditions and some special parameters like particular climate conditions or lack of infrastructure for a special site the could modify the results shown on the curves. The variety of wind turbines (rated power as a function of rotor diameter, height and specific rated power) in the actual market is analyzed. A brief analysis of the market trend is also performed. 7 refs., 7 figs.

  15. Technologies for production of electricity and heat in Sweden. Wind energy in perspective of international development

    Energy Technology Data Exchange (ETDEWEB)

    Clausen, Niels-Erik; Lawaetz, Henrik; Lemming, Joergen; Morthorst, Poul Erik

    2008-12-15

    The development of the wind energy technology has been very successful from the 1970s and up till now. Initially there was a battle between wind turbine concepts, but the commercial winner today is the three-bladed horizontal axis, upwind, electricity producing and grid connected wind turbine with availability on mature markets somewhere around 99%. An important contributor to the growth of the European market for wind energy technology has been EU framework legislation combined with legislation at the national level. The binding target for renewable energy in Sweden is proposed to be 49% of the final energy consumption in 2020 compared to 39.8% in 2005. To stimulate the development of wind energy and to promote a specific national goals Sweden is mainly using an electricity certificate system. The target is to increase the production of electricity from renewable sources by 17 TWh in 2016, relative to corresponding production in 2002. There is not at specific target for the use of wind energy. A future energy system that includes a high proportion of wind energy will be expected to meet the same requirements for security of supply and economic efficiency as the energy systems of today. The variability of wind power create a specific challenges for the future energy systems compared to those of today. The economics of wind power depends mainly of investment cost, operation and maintenance costs, electricity production and turbine lifetime. An average turbine installed in Europe has a total investment cost of 1.230 Euro/kW with a typically variation from approximately 1000 Euro/kW to approximately 1400 Euro/kW. The calculated costs per kWh wind generated power range from approximately 7-10 cEuro/kWh at sites with low average wind speeds to approximately 5-6.5 cEuro/kWh at good coastal positions, with an average of approximately 7cEuro/kWh at a medium wind site. Offshore costs are largely dependent on weather and wave conditions, water depth, and distance to the

  16. Evaluation of satellite rainfall products through hydrologic simulation in a fully distributed hydrologic model

    Science.gov (United States)

    Bitew, Menberu M.; Gebremichael, Mekonnen

    2011-06-01

    The goal of this study is to evaluate the accuracy of four global high-resolution satellite rainfall products (CMORPH, TMPA 3B42RT, TMPA 3B42, and PERSIANN) through the hydrologic simulation of a 1656 km2 mountainous watershed in the fully distributed MIKE SHE hydrologic model. This study shows that there are significant biases in the satellite rainfall estimates and large variations in rainfall amounts, leading to large variations in hydrologic simulations. The rainfall algorithms that use primarily microwave data (CMORPH and TMPA 3B42RT) show consistent and better performance in streamflow simulation (bias in the order of -53% to -3%, Nash-Sutcliffe efficiency (NSE) from 0.34 to 0.65); the rainfall algorithm that uses primarily infrared data (PERSIANN) shows lower performance (bias from -82% to -3%, Nash-Sutcliffe efficiency from -0.39 to 0.43); and the rainfall algorithm that merges the satellite data with rain gage data (TMPA 3B42) shows inconsistencies and the lowest performance (bias from -86% to 0.43%, Nash-Sutcliffe efficiency from -0.50 to 0.27). A dilemma between calibrating the hydrologic model with rain gage data and calibrating it with the corresponding satellite rainfall data is presented. Calibrating the model with corresponding satellite rainfall data increases the performance of satellite streamflow simulation compared to the model calibrated with rain gage data, but decreases the performance of satellite evapotranspiration simulation.

  17. Evaluation of Satellite Rainfall Products over NASA's Iowa Flood Studies (IFloodS) Domain

    Science.gov (United States)

    ElSaadani, Mohamed; Quintero, Felipe; Krajewski, Witold F.; Goska, Radoslaw; Seo, Bongchul

    2014-05-01

    Iowa Flood Studies (IFloodS) is a NASA Global Precipitation Measurement (GPM) Mission to provide better understanding of the strengths and limitations of satellite products in the context of hydrologic applications. IFloodS took place in the central to north eastern part of Iowa in Midwestern United States during the months of April-June, 2013. Quantifying the physical characteristics, space/time variability and assessing satellite rainfall retrieval uncertainties at instantaneous to daily time scales are of the main objectives of IFloodS field experiment beside assessing hydrologic predictive skills as a function of space/time scales and discerning the relative roles of rainfall quantities in flood genesis. The errors of rainfall estimation of three satellite rainfall products (TRMM's TMPA 3B42 V7, CPC's CMORPH and CHRS at UCI's PERSIANN) have been characterized in space and time using NCEP Stage IV radar-rainfall product as a benchmark for comparison. The satellite rainfall products used in this study represent 3 hourly, quarter degree, rainfall accumulation. The benchmark rainfall accumulation has an hourly, four kilometers, resolutions in time and space respectively. We also investigate the adequacy of satellite rainfall products as inputs for hydrological modeling. To this end, these products were used as forcing for the Iowa Flood Center (IFC) hydrological model and produced discharge simulations in a high-resolution drainage network. The IFC hydrological model has been validated using radar rainfall product and thus, the hydrological outputs becomes the reference of comparison for the other rainfall products. We evaluated the hydrological performance of the rainfall products at different spatial scales, ranging from 2 to 14,000 square miles using stream discharge information from USGS gauges network. We discuss the adequacy of the rainfall products for flood forecasting at different spatial scales.

  18. Gap Filling of the CALYPSO HF Radar Sea Surface Current Data through Past Measurements and Satellite Wind Observations

    Directory of Open Access Journals (Sweden)

    Adam Gauci

    2016-01-01

    Full Text Available High frequency (HF radar installations are becoming essential components of operational real-time marine monitoring systems. The underlying technology is being further enhanced to fully exploit the potential of mapping sea surface currents and wave fields over wide areas with high spatial and temporal resolution, even in adverse meteo-marine conditions. Data applications are opening to many different sectors, reaching out beyond research and monitoring, targeting downstream services in support to key national and regional stakeholders. In the CALYPSO project, the HF radar system composed of CODAR SeaSonde stations installed in the Malta Channel is specifically serving to assist in the response against marine oil spills and to support search and rescue at sea. One key drawback concerns the sporadic inconsistency in the spatial coverage of radar data which is dictated by the sea state as well as by interference from unknown sources that may be competing with transmissions in the same frequency band. This work investigates the use of Machine Learning techniques to fill in missing data in a high resolution grid. Past radar data and wind vectors obtained from satellites are used to predict missing information and provide a more consistent dataset.

  19. The Multi-Sensor Aerosol Products Sampling System (MAPSS) for Integrated Analysis of Satellite Retrieval Uncertainties

    Science.gov (United States)

    Ichoku, Charles; Petrenko, Maksym; Leptoukh, Gregory

    2010-01-01

    Among the known atmospheric constituents, aerosols represent the greatest uncertainty in climate research. Although satellite-based aerosol retrieval has practically become routine, especially during the last decade, there is often disagreement between similar aerosol parameters retrieved from different sensors, leaving users confused as to which sensors to trust for answering important science questions about the distribution, properties, and impacts of aerosols. As long as there is no consensus and the inconsistencies are not well characterized and understood ', there will be no way of developing reliable climate data records from satellite aerosol measurements. Fortunately, the most globally representative well-calibrated ground-based aerosol measurements corresponding to the satellite-retrieved products are available from the Aerosol Robotic Network (AERONET). To adequately utilize the advantages offered by this vital resource,., an online Multi-sensor Aerosol Products Sampling System (MAPSS) was recently developed. The aim of MAPSS is to facilitate detailed comparative analysis of satellite aerosol measurements from different sensors (Terra-MODIS, Aqua-MODIS, Terra-MISR, Aura-OMI, Parasol-POLDER, and Calipso-CALIOP) based on the collocation of these data products over AERONET stations. In this presentation, we will describe the strategy of the MAPSS system, its potential advantages for the aerosol community, and the preliminary results of an integrated comparative uncertainty analysis of aerosol products from multiple satellite sensors.

  20. Toward a Coherent Detailed Evaluation of Aerosol Data Products from Multiple Satellite Sensors

    Science.gov (United States)

    Ichoku, Charles; Petrenko, Maksym; Leptoukh, Gregory

    2011-01-01

    Atmospheric aerosols represent one of the greatest uncertainties in climate research. Although satellite-based aerosol retrieval has practically become routine, especially during the last decade, there is often disagreement between similar aerosol parameters retrieved from different sensors, leaving users confused as to which sensors to trust for answering important science questions about the distribution, properties, and impacts of aerosols. As long as there is no consensus and the inconsistencies are not well characterized and understood, there will be no way of developing reliable climate data records from satellite aerosol measurements. Fortunately, the most globally representative well-calibrated ground-based aerosol measurements corresponding to the satellite-retrieved products are available from the Aerosol Robotic Network (AERONET). To adequately utilize the advantages offered by this vital resource, an online Multi-sensor Aerosol Products Sampling System (MAPSS) was recently developed. The aim of MAPSS is to facilitate detailed comparative analysis of satellite aerosol measurements from different sensors (Terra-MODIS, Aqua-MODIS, TerraMISR, Aura-OMI, Parasol-POLDER, and Calipso-CALIOP) based on the collocation of these data products over AERONET stations. In this presentation, we will describe the strategy of the MASS system, its potential advantages for the aerosol community, and the preliminary results of an integrated comparative uncertainly analysis of aerosol products from multiple satellite sensors.

  1. Introducing life cycle thinking in product development – A case from Siemens Wind Power

    DEFF Research Database (Denmark)

    Bonou, Alexandra; Olsen, Stig Irving; Hauschild, Michael Zwicky

    2015-01-01

    How can use of LCA improve the environmental sustainability of wind industry products? An analysis of a case study from Siemens Wind Power identifies the knowledge offered by LCA that is relevant to each step of the product development process (PDP). The study illustrates the difference...... that this knowledge can make to the decision making in the PDP and to the environmental sustainability of the product. Based on these findings, the study concludes with a discussion of barriers for LCA integration in the PDP of complex products and possible measures to overcome them....

  2. Introducing life cycle thinking in product development – A case from Siemens Wind Power

    DEFF Research Database (Denmark)

    Bonou, Alexandra; Olsen, Stig Irving; Hauschild, Michael Zwicky

    2015-01-01

    How can use of LCA improve the environmental sustainability of wind industry products? An analysis of a case study from Siemens Wind Power identifies the knowledge offered by LCA that is relevant to each step of the product development process (PDP). The study illustrates the difference...... that this knowledge can make to the decision making in the PDP and to the environmental sustainability of the product. Based on these findings, the study concludes with a discussion of barriers for LCA integration in the PDP of complex products and possible measures to overcome them....

  3. Satellite-based Flood Modeling Using TRMM-based Rainfall Products

    Directory of Open Access Journals (Sweden)

    Greg Easson

    2007-12-01

    Full Text Available Increasingly available and a virtually uninterrupted supply of satellite-estimatedrainfall data is gradually becoming a cost-effective source of input for flood predictionunder a variety of circumstances. However, most real-time and quasi-global satelliterainfall products are currently available at spatial scales ranging from 0.25o to 0.50o andhence, are considered somewhat coarse for dynamic hydrologic modeling of basin-scaleflood events. This study assesses the question: what are the hydrologic implications ofuncertainty of satellite rainfall data at the coarse scale? We investigated this question onthe 970 km2 Upper Cumberland river basin of Kentucky. The satellite rainfall productassessed was NASA’s Tropical Rainfall Measuring Mission (TRMM Multi-satellitePrecipitation Analysis (TMPA product called 3B41RT that is available in pseudo real timewith a latency of 6-10 hours. We observed that bias adjustment of satellite rainfall data canimprove application in flood prediction to some extent with the trade-off of more falsealarms in peak flow. However, a more rational and regime-based adjustment procedureneeds to be identified before the use of satellite data can be institutionalized among floodmodelers.

  4. Application of AZ4903 to production of stator windings

    Institute of Scientific and Technical Information of China (English)

    Zhanshe GUO; Yihui WU; Yonggang MENG; Dezhi ZHENG

    2008-01-01

    To satisfy the needs of the high deep-width ratio and thickness of a planar micromotor's stator windings, a process method to produce an electromag-netic planar micromotor with AZ4903 is proposed. Optimum relationships, such as the desired rotation speed vs. thickness of the coating process, and the temperature vs. time of pre-baking, are obtained. The appropriate time of lithography and development are also achieved. The thickness of the produced windings is 40 μm with ideal perpendicularity. Finally, stators and rotors are fabricated. The rotation speed and pull-out torque of the micromotor are tested. The experiment proved that the micromotor worked with a steady speed and a low ripple of pull-out torque.

  5. Satellite Data Product and Data Dissemination Updates for the SPoRT Sea Surface Temperature Composite Product

    Science.gov (United States)

    Zavodsky, Bradley; LaFontaine, Frank; Berndt, Emily; Meyer, Paul; Jedlovec, Gary

    2017-01-01

    The SPoRT SST composite is a reliable and robust high-resolution product generated twice per day in near real time. It incorporates highest quality data satellite data from infrared imagers and global analysis from NESDIS and UKMO. Recent updates to the product include the inclusion of VIIRS data to extend the life of the product beyond the MODIS era. It is used by a number of users in their DSS.

  6. Supply Chain Management of Satellite Mechanisms- Product Development and Monitoring

    Directory of Open Access Journals (Sweden)

    Sreejith

    2014-01-01

    Full Text Available The project report primary deals with the Testing, Analysis, Modeling of the components of the Solar Array deployment Mechanism and a preliminary design. It also discusses the Monitoring of the supply chain management system for the procurement of the components from vendors. The deployment of solar array or any other appendage is a mission critical activity of any satellite. It is necessary to study about the deployment mechanism because once the array latches up, the satellite can have disturbance resulting in attitude change. To begin, a detail study of the drawings of all the components, assemblies and sub-assemblies incorporated in the deployment mechanism was done. A literary review was carried out to investigate the research done previously and the research currently being done in the field of deployment mechanisms. This was followed by the designing of the components of SADM in Unigraphics. The components were assembled with their respective sub-assemblies. The next step was to perform the testing of components on various testing machines & thereafter analyzing the results. A conceptual design was prepared for the Solar Array Deployment Mechanism. A proper approach was used for the supply chain management of the procurement of raw materials.The torsion spring parameters were calculated, which importantly included the pre rotation angle, spring angular and the time required by the wings to deploy. The hinges were tested on the auto hinge characterization setup and the torque value required to deploy the wings was compared with the required value. The testing of micro switches was performed and the values of loads at actuation point, deactuation point, over travel and the gap between actuation and deactuation was compared with the actual values required. Torsion springs were tested and it was seen whether the stiffness values of the torsion springs are in limit to the defined value or not.Several components of Solar Array Deployment

  7. Study on the product estimation of small wind turbines; Kogata fusha no hatsudenryo yosoku ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Matsuzawa, K.; Kimura, Y.; Ushiyama, I. [Ashikaga Institute of Technology, Tochigi (Japan); Nagai, H. [Nihon Univ., Chiba (Japan). Coll. of Industrial Technology

    1998-09-01

    In order to clarify problems involved in application of Weibull probability distribution used for estimation of power production by a large wind turbine to a small wind turbine, and solutions thereof, the estimated results are compared with the observed ones. The conventional estimation method, when applied to a small wind turbine, tends to overestimate production of power, because of overestimated production in a high wind velocity range which occurs less frequently. Estimation of power produced by a wind turbine is based on working wind velocity range, determined from the furling mechanism for the power generation characteristics of the wind turbine concerned. In the case of a small wind turbine, on the other hand, better estimates are obtained from the working wind velocity range in which Weibull wind velocity distribution is used to determine probability of occurrence. For wind turbines working at low to medium wind velocities, such as Savonius wind turbine, the estimates are in fairly good agreement with the observed results, by which is meant that the conventional estimation method aided by Weibull distribution can be directly applicable to small wind turbines. 4 refs., 3 figs., 3 tabs.

  8. Evaluation of satellite based indices for primary production estimates in a sparse savanna in the Sudan

    Directory of Open Access Journals (Sweden)

    M. Sjöström

    2008-07-01

    Full Text Available One of the more frequently applied methods for integrating controls on primary production through satellite data is the Light Use Efficiency (LUE approach. Satellite indices such as the Enhanced Vegetation Index (EVI and the Shortwave Infrared Water Stress Index (SIWSI have previously shown promise as predictors of primary production in several different environments. In this study, we evaluate EVI and SIWSI derived from the Moderate Resolution Imaging Spectroradiometer (MODIS satellite sensor against in-situ measurements from central Sudan in order to asses their applicability in LUE-based primary production modelling within a water limited environment. Results show a strong correlation between EVI against gross primary production (GPP, demonstrating the significance of EVI for deriving information on primary production with relatively high accuracy at similar areas. Evaluation of SIWSI however, reveal that the fraction of vegetation apparently is to low for the index to provide accurate information on canopy water content, indicating that the use of SIWSI as a predictor of water stress in satellite data-driven primary production modelling in similar semi-arid ecosystems is limited.

  9. Assessment and Analysis of QuikSCAT Vector Wind Products for the Gulf of Mexico: A Long-Term and Hurricane Analysis

    Directory of Open Access Journals (Sweden)

    Eurico D’Sa

    2008-03-01

    Full Text Available The northern Gulf of Mexico is a region that has been frequently impacted in recent years by natural disasters such as hurricanes. The use of remote sensing data such as winds from NASA’s QuikSCAT satellite sensor would be useful for emergency preparedness during such events. In this study, the performance of QuikSCAT products, including JPL’s latest Level 2B (L2B 12.5 km swath winds, were evaluated with respect to buoy-measured winds in the Gulf of Mexico for the period January 2005 to February 2007. Regression analyses indicated better accuracy of QuikSCAT’s L2B DIRTH, 12.5 km than the Level 3 (L3, 25 km wind product. QuikSCAT wind data were compared directly with buoy data keeping a maximum time interval of 20 min and spatial interval of 0.1° (≈10 km. R2 values for moderate wind speeds were 0.88 and 0.93 for L2B, and 0.75 and 0.89 for L3 for speed and direction, respectively. QuikSCAT wind comparisons for buoys located offshore were better than those located near the coast. Hurricanes that took place during 2002-06 were studied individually to obtain regressions of QuikSCAT versus buoys for those events. Results show QuikSCAT’s L2B DIRTH wind product compared well with buoys during hurricanes up to the limit of buoy measurements. Comparisons with the National Hurricane Center (NHC best track analyses indicated QuikSCAT winds to be lower than those obtained by NHC, possibly due to rain contamination, while buoy measurements appeared to be constrained at high wind speeds. This study has confirmed good agreement of the new QuikSCAT L2B product with buoy measurements and further suggests its potential use during extreme weather conditions in the Gulf of Mexico.

  10. An Overview of the Joint Polar Satellite System (JPSS Science Data Product Calibration and Validation

    Directory of Open Access Journals (Sweden)

    Lihang Zhou

    2016-02-01

    Full Text Available The Joint Polar Satellite System (JPSS will launch its first JPSS-1 satellite in early 2017. The JPSS-1 and follow-on satellites will carry aboard an array of instruments including the Visible Infrared Imaging Radiometer Suite (VIIRS, the Cross-track Infrared Sounder (CrIS, the Advanced Technology Microwave Sounder (ATMS, and the Ozone Mapping and Profiler Suite (OMPS. These instruments are similar to the instruments currently operating on the Suomi National Polar-orbiting Partnership (S-NPP satellite. In preparation for the JPSS-1 launch, the JPSS program at the Center for Satellite Applications and Research (JSTAR Calibration/Validation (Cal/Val teams, have laid out the Cal/Val plans to oversee JPSS-1 science products’ algorithm development efforts, verification and characterization of these algorithms during the pre-launch period, calibration and validation of the products during post-launch, and long-term science maintenance (LTSM. In addition, the team has developed the necessary schedules, deliverables and infrastructure for routing JPSS-1 science product algorithms for operational implementation. This paper presents an overview of these efforts. In addition, this paper will provide insight into the processes of both adapting S-NPP science products for JPSS-1 and performing upgrades for enterprise solutions, and will discuss Cal/Val processes and quality assurance procedures.

  11. Inter-Comparison of High-Resolution Satellite Precipitation Products over Central Asia

    Directory of Open Access Journals (Sweden)

    Hao Guo

    2015-06-01

    Full Text Available This paper examines the spatial error structures of eight precipitation estimates derived from four different satellite retrieval algorithms including TRMM Multi-satellite Precipitation Analysis (TMPA, Climate Prediction Center morphing technique (CMORPH, Global Satellite Mapping of Precipitation (GSMaP and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN. All the original satellite and bias-corrected products of each algorithm (3B42RTV7 and 3B42V7, CMORPH_RAW and CMORPH_CRT, GSMaP_MVK and GSMaP_Gauge, PERSIANN_RAW and PERSIANN_CDR are evaluated against ground-based Asian Precipitation-Highly Resolved Observational Data Integration Towards Evaluation of Water Resources (APHRODITE over Central Asia for the period of 2004 to 2006. The analyses show that all products except PERSIANN exhibit overestimation over Aral Sea and its surrounding areas. The bias-correction improves the quality of the original satellite TMPA products and GSMaP significantly but slightly in CMORPH and PERSIANN over Central Asia. 3B42RTV7 overestimates precipitation significantly with large Relative Bias (RB (128.17% while GSMaP_Gauge shows consistent high correlation coefficient (CC (>0.8 but RB fluctuates between −57.95% and 112.63%. The PERSIANN_CDR outperforms other products in winter with the highest CC (0.67. Both the satellite-only and gauge adjusted products have particularly poor performance in detecting rainfall events in terms of lower POD (less than 65%, CSI (less than 45% and relatively high FAR (more than 35%.

  12. Large variability in continental shelf production of phytoplankton carbon revealed by satellite

    Directory of Open Access Journals (Sweden)

    B. F. Jönsson

    2010-12-01

    Full Text Available We estimate the net production of phytoplankton in the Gulf of Maine (GoM over a 3-year period using satellite ocean color data in conjunction with surface velocities from a high-resolution operational ocean circulation model. Chlorophyll (chl-a and light attenuation (K490 products are combined with a carbon to chlorophyll model to estimate the phytoplankton carbon (PC stock in the euphotic layer. A satellite-based productivity, termed NCPe in analogy with net community production (NCP, is derived by tracking changes in satellite-derived PC from one satellite image to the next, along water parcel trajectories calculated with surface velocities from the ocean circulation model. Such an along-trajectory analysis of satellite data discounts the effect of advection that would otherwise contribute to the temporal change between consecutive images viewed in the fixed reference frame. Our results show a high variability of up to ± 500 mg C m−2 d−1 in NCPe on spatial scales of 10–100 km. A region-wide median NCPe of 40–50 mg C m−2 d−1 is often prevalent in the Gulf, while blooms attain peak values of 400 mg C m−2 d−1 for a few days. The spatio-temporal variability of NCPe in this region, though conditioned by seasonality, is dominated by events lasting a few days, which if integrated, lead to large inter-annual variability in the annual carbon budget. This study is a step toward achieving synoptic and time-dependent estimates of oceanic productivity and NCP from satellite data.

  13. Application of satellite products and hydrological modelling for flood early warning

    Science.gov (United States)

    Koriche, Sifan A.; Rientjes, Tom H. M.

    2016-06-01

    Floods have caused devastating impacts to the environment and society in Awash River Basin, Ethiopia. Since flooding events are frequent, this marks the need to develop tools for flood early warning. In this study, we propose a satellite based flood index to identify the runoff source areas that largely contribute to extreme runoff production and floods in the basin. Satellite based products used for development of the flood index are CMORPH (Climate Prediction Center MORPHing technique: 0.25° by 0.25°, daily) product for calculation of the Standard Precipitation Index (SPI) and a Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) for calculation of the Topographic Wetness Index (TWI). Other satellite products used in this study are for rainfall-runoff modelling to represent rainfall, potential evapotranspiration, vegetation cover and topography. Results of the study show that assessment of spatial and temporal rainfall variability by satellite products may well serve in flood early warning. Preliminary findings on effectiveness of the flood index developed in this study indicate that the index is well suited for flood early warning. The index combines SPI and TWI, and preliminary results illustrate the spatial distribution of likely runoff source areas that cause floods in flood prone areas.

  14. A Generalized Statistical Uncertainty Model for Satellite Precipitation Products

    Science.gov (United States)

    Sarachi, S.

    2013-12-01

    A mixture model of Generalized Normal Distribution and Gamma distribution (GND-G) is used to model the joint probability distribution of satellite-based and stage IV radar rainfall under a given spatial and temporal resolution (e.g. 1°x1° and daily rainfall). The distribution parameters of GND-G are extended across various rainfall rates and spatial and temporal resolutions. In the study, GND-G is used to describe the uncertainty of the estimates from Precipitation Estimation from Remote Sensing Information using Artificial Neural Network algorithm (PERSIANN). The stage IV-based multi-sensor precipitation estimates (MPE) are used as reference measurements .The study area for constructing the uncertainty model covers a 15°×15°box of 0.25°×0.25° cells over the eastern United States for summer 2004 to 2009. Cells are aggregated in space and time to obtain data with different resolutions for the construction of the model's parameter space. Result shows that comparing to the other statistical uncertainty models, GND-G fits better than the other models, such as Gaussian and Gamma distributions, to the reference precipitation data. The impact of precipitation uncertainty to the stream flow is further demonstrated by Monte Carlo simulation of precipitation forcing in the hydrologic model. The NWS DMIP2 basins over Illinois River basin south of Siloam is selected in this case study. The data covers the time period of 2006 to 2008.The uncertainty range of stream flow from precipitation of GND-G distributions calculated and will be discussed.

  15. Comparison of Wind energy production forecasts, in terms of errors and economic losses

    Science.gov (United States)

    Mestre, O.; Texier, O.; Girard, N.; Usaola, J.; Bantegnie, P.

    2009-04-01

    We compare 6 forecasts productions models on two windfarms located in France. The evaluation is made in terms of root mean square errors. The power production forecasts are the products of both physical and statistical models and cover a period of 6 months. We show that the economic performances of those models can be improved using econometric approaches, where we to minimize the cost induced by the forecast error instead of minimizing the forecast error itself. This technique relies on state of the art non-parametric estimators of conditional probability distribution functions (cpdf) of energy production at a wind farm, given the wind speed forecasts of a deterministic meteorological model. In this case, no assumption is made about the shape of the underlying laws. The economical benefits of ensemble versus deterministic wind speed forecasts are also assessed.

  16. Wind-Friendly Flexible Ramping Product Design in Multi-Timescale Power System Operations

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Mingjian; Zhang, Jie; Wu, Hongyu; Hodge, Bri-Mathias

    2017-07-01

    With increasing wind power penetration in the electricity grid, system operators are recognizing the need for additional flexibility, and some are implementing new ramping products as a type of ancillary service. However, wind is generally thought of as causing the need for ramping services, not as being a potential source for the service. In this paper, a multi-timescale unit commitment and economic dispatch model is developed to consider the wind power ramping product (WPRP). An optimized swinging door algorithm with dynamic programming is applied to identify and forecast wind power ramps (WPRs). Designed as positive characteristics of WPRs, the WPRP is then integrated into the multi-timescale dispatch model that considers new objective functions, ramping capacity limits, active power limits, and flexible ramping requirements. Numerical simulations on the modified IEEE 118-bus system show the potential effectiveness of WPRP in increasing the economic efficiency of power system operations with high levels of wind power penetration. It is found that WPRP not only reduces the production cost by using less ramping reserves scheduled by conventional generators, but also possibly enhances the reliability of power system operations. Moreover, wind power forecasts play an important role in providing high-quality WPRP service.

  17. Mapping Wind Farm Loads and Power Production - A Case Study on Horns Rev 1

    Science.gov (United States)

    Galinos, Christos; Dimitrov, Nikolay; Larsen, Torben J.; Natarajan, Anand; Hansen, Kurt S.

    2016-09-01

    This paper describes the development of a wind turbine (WT) component lifetime fatigue load variation map within an offshore wind farm. A case study on the offshore wind farm Horns Rev I is conducted with this purpose, by quantifying wake effects using the Dynamic Wake Meandering (DWM) method, which has previously been validated based on CFD, Lidar and full scale load measurements. Fully coupled aeroelastic load simulations using turbulent wind conditions are conducted for all wind directions and mean wind speeds between cut-in and cut-out using site specific turbulence level measurements. Based on the mean wind speed and direction distribution, the representative 20-year lifetime fatigue loads are calculated. It is found that the heaviest loaded WT is not the same when looking at blade root, tower top or tower base components. The blade loads are mainly dominated by the wake situations above rated wind speed and the highest loaded blades are in the easternmost row as the dominating wind direction is from West. Regarding the tower components, the highest loaded WTs are also located towards the eastern central location. The turbines with highest power production are, not surprisingly, the ones facing a free sector towards west and south. The power production results of few turbines are compared with SCADA data. The results of this paper are expected to have significance for operation and maintenance planning, where the schedules for inspection and service activities can be adjusted to the requirements arising from the varying fatigue levels. Furthermore, the results can be used in the context of remaining fatigue lifetime assessment and planning of decommissioning.

  18. Offshore wind potential in Libya: possibilities for strategic plans for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    El-Osta, W.; Khalifa, Y. [Center for Solar Energy Studies, Tripoli (Libya)

    2002-07-01

    In Libya the wind potential, in-land, probably is not very high. The wind speed on the coast ranges between 5.5am/s and 7.9am/s at 10am a.g.l. in regions of roughness class 1. The wind potential offshore is not assessed yet. Unfortunately, there are no real measurements at sea. WAsP software was used to assess the wind potential at the Mediterranean sea at distances close to the coast. So wind data from the 9-Meteorological stations exist .on the coast was used and was extrapolated to offshore region. The results revealed that the wind speed offshore ranges between 6.8am/s and 8.9am/s at 10am height and from 8am/s to 10.4am/s at 50am height. Consequently the available power ranges from 435aw/m{sup 2} to 1483aw/m{sup 2} at 10am height and from 661aw/m{sup 2} to 2242aw/m{sup 2} at 50am height.The population density in Libya, with respect to the total area, is very low compared to other regions ( 2.9apersons/km{sup 2}). The energy demand is growing very fast through the last several years, and if the wind potential in-land was exploited; even with this fast growing electric energy demand, it could be more than sufficient to meet this demand (ignoring technical and economic constrains and other limitations). But the wind potential at the sea would be, for sure, much greater than that inland. Since the wind potential still has not been exploited, it might be beneficial to exploite the wind potential offshore for the following reasons: The wind potential is higher than the potential in-land. To solve the future expected problems of water-shortages in some regions by water desalination using wind power. Use wind power, and probably other solar technologies, to produce hydrogen for local supply ofahydrogen energy and for export to European countries. This paper will assess the wind potential offshore in Libya and will discuss the possibility of hydrogen production for local consumption and hydrogen export to Europe. The technical and financial problems and costraints that

  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. World Wind

    Data.gov (United States)

    National Aeronautics and Space Administration — World Wind allows any user to zoom from satellite altitude into any place on Earth, leveraging high resolution LandSat imagery and SRTM elevation data to experience...

  1. Satellite remote sensing for estimating leaf area index, FPAR and primary production. A literature review

    Energy Technology Data Exchange (ETDEWEB)

    Boresjoe Bronge, Laine [SwedPower AB, Stockholm (Sweden)

    2004-03-01

    Land vegetation is a critical component of several biogeochemical cycles that have become the focus of concerted international research effort. Most ecosystem productivity models, carbon budget models, and global models of climate, hydrology and biogeochemistry require vegetation parameters to calculate land surface photosynthesis, evapotranspiration and net primary production. Therefore, accurate estimates of vegetation parameters are increasingly important in the carbon cycle, the energy balance and in environmental impact assessment studies. The possibility of quantitatively estimating vegetation parameters of importance in this context using satellite data has been explored by numerous papers dealing with the subject. This report gives a summary of the present status and applicability of satellite remote sensing for estimating vegetation productivity by using vegetation index for calculating leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FPAR). Some possible approaches for use of satellite data for estimating LAI, FPAR and net primary production (NPP) on a local scale are suggested. Recommendations for continued work in the Forsmark and Oskarshamn investigation areas, where vegetation data and NDVI-images based on satellite data have been produced, are also given.

  2. A Review of Global Satellite-derived Snow Products

    Science.gov (United States)

    Frei, Allan; Tedesco, Marco; Lee, Shihyan; Foster, James; Hall, Dorothy K.; Kelly, Richard; Robinson, David A.

    2012-01-01

    Snow cover over the Northern Hemisphere plays a crucial role in the Earth's hydrology and surface energy balance, and modulates feedbacks that control variations of global climate. While many of these variations are associated with exchanges of energy and mass between the land surface and the atmosphere, other expected changes are likely to propagate downstream and affect oceanic processes in coastal zones. For example, a large component of the freshwater flux into the Arctic Ocean comes from snow melt. The timing and magnitude of this flux affects biological and thermodynamic processes in the Arctic Ocean, and potentially across the globe through their impact on North Atlantic Deep Water formation. Several recent global remotely sensed products provide information at unprecedented temporal, spatial, and spectral resolutions. In this article we review the theoretical underpinnings and characteristics of three key products. We also demonstrate the seasonal and spatial patterns of agreement and disagreement amongst them, and discuss current and future directions in their application and development. Though there is general agreement amongst these products, there can be disagreement over certain geographic regions and under conditions of ephemeral, patchy and melting snow.

  3. The effect of blockage on power production for laterally aligned wind turbines

    Science.gov (United States)

    Meyer Forsting, A. R.; Troldborg, N.

    2015-06-01

    This paper studies the change in the individual power coefficients for a laterally aligned row of wind turbines over a single, free turbine in the context of varying inflow directions via numerical simulations. All turbines were rotating in-line with the main flow direction. The problem definition is similar to that of many wind turbine testing sites and wind farms. Hence any changes in the individual turbine power production could have implications regarding power curve validation procedures.These changes are relatively small and therefore the size of the computational domain was identified to be detrimental in avoiding any domain-inflicted blockage. Increasing the misalignment of the main flow direction with the row of turbines led to significant variations in the power production across turbines. At the largest inflow angle of 45° it varied from -1.1% to 2%. As a whole, the power production increased by about 0.5%, almost independent of the inflow direction.

  4. A model for gamma-ray binaries, based on the effect of pair production feedback in shocked pulsar winds

    CERN Document Server

    Derishev, E

    2016-01-01

    We analyze the model of gamma-ray binaries, consisting of a massive star and a pulsar with ultrarelativistic wind. We consider radiation from energetic particles, accelerated at the pulsar wind termination shock, and feedback of this radiation on the wind through production of secondary electron-positron pairs. We show that the pair feedback limits the Lorentz factor of the pulsar wind and creates a population of very energetic pairs, whose radiation may be responsible for the observed gamma-ray signal.

  5. From probabilistic forecasts to statistical scenarios of short-term wind power production

    DEFF Research Database (Denmark)

    Pinson, Pierre; Papaefthymiou, George; Klockl, Bernd;

    2009-01-01

    Short-term (up to 2-3 days ahead) probabilistic forecasts of wind power provide forecast users with highly valuable information on the uncertainty of expected wind generation. Whatever the type of these probabilistic forecasts, they are produced on a per horizon basis, and hence do not inform....... This issue is addressed here by describing a method that permits the generation of statistical scenarios of short-term wind generation that accounts for both the interdependence structure of prediction errors and the predictive distributions of wind power production. The method is based on the conversion...... of series of prediction errors to a multivariate Gaussian random variable, the interdependence structure of which can then be summarized by a unique covariance matrix. Such matrix is recursively estimated in order to accommodate long-term variations in the prediction error characteristics. The quality...

  6. Validation of satellite SAR offshore wind speed maps to in-situ data, microscale and mesoscale model results

    DEFF Research Database (Denmark)

    Hasager, C.B.; Astrup, Poul; Barthelmie, R.J.

    2002-01-01

    planning of offshore wind farms. The report describes the validation analysis in detail for three sites in Denmark, Italy and Egypt. The site in Norway is analyzed by the Nansen Environmental and Remote SensingCentre (NERSC). Wind speed maps and wind direction maps from Earth Observation data recorded...... band in which the SAR wind speed observations have a strong negative bias. The bathymetry of Horns Rev combined with tidal currents give rise to bias in the SAR wind speed maps near areas of shallow, complex bottom topography in some cases. Atotal of 16 cases were analyzed for Horns Rev. For Maddalena...

  7. Long Term Assessment of ERS-1 and ERS-2 Wind and Wave Products Using ERA-Interim

    Science.gov (United States)

    Aballa, Saleh; Hersbach, Hans; Bidlot, Jean-Raymond

    2010-12-01

    The ERS mission is a great opportunity for the meteorological and ocean-wave communities. In particular, the wind and wave products from both ERS-1 and ERS-2 provide an invaluable data set. The quality of the fast delivery (FD) products of scatterometer wind (UWI), SAR Wave Mode (UWA) and radar altimeter wind and wave (URA) and the off- line OPR (Ocean Product) altimeter wind and wave products were already assessed against the consistent ECMWF 40-Year Reanalysis (ERA-40) wind fields and presented by Hersbach et al. [1]. The recent availability of the higher quality ECMWF interim reanalysis (ERA- Interim) motivated us to repeat the same exercise to get a better evaluation of the quality of ERS wind and wave products.

  8. Mapping Surface Broadband Albedo from Satellite Observations: A Review of Literatures on Algorithms and Products

    Directory of Open Access Journals (Sweden)

    Ying Qu

    2015-01-01

    Full Text Available Surface albedo is one of the key controlling geophysical parameters in the surface energy budget studies, and its temporal and spatial variation is closely related to the global climate change and regional weather system due to the albedo feedback mechanism. As an efficient tool for monitoring the surfaces of the Earth, remote sensing is widely used for deriving long-term surface broadband albedo with various geostationary and polar-orbit satellite platforms in recent decades. Moreover, the algorithms for estimating surface broadband albedo from satellite observations, including narrow-to-broadband conversions, bidirectional reflectance distribution function (BRDF angular modeling, direct-estimation algorithm and the algorithms for estimating albedo from geostationary satellite data, are developed and improved. In this paper, we present a comprehensive literature review on algorithms and products for mapping surface broadband albedo with satellite observations and provide a discussion of different algorithms and products in a historical perspective based on citation analysis of the published literature. This paper shows that the observation technologies and accuracy requirement of applications are important, and long-term, global fully-covered (including land, ocean, and sea-ice surfaces, gap-free, surface broadband albedo products with higher spatial and temporal resolution are required for climate change, surface energy budget, and hydrological studies.

  9. Detecting weather radar clutter using satellite-based nowcasting products

    DEFF Research Database (Denmark)

    Jensen, Thomas B.S.; Gill, Rashpal S.; Overgaard, Søren

    2006-01-01

    for the detecting and removal of clutter. Naturally, the improved spatio-temporal resolution of the Meteosat Second Generation sensors, coupled with its increased number of spectral bands, is expected to yield even better detection accuracies. Weather radar data from three C-band Doppler weather radars...... Application Facility' of EUMETSAT and is based on multispectral images from the SEVIRI sensor of the Meteosat-8 platform. Of special interest is the 'Precipitating Clouds' product, which uses the spectral information coupled with surface temperatures from Numerical Weather Predictions to assign probabilities...... by the resolution of the radar data. Subsequently, a supervised classifier was developed based on training data selected by a weather radar expert. Results of classification of data from several different meteorological events are shown. Cases of widespread sea clutter caused by anomalous propagation are especially...

  10. Next-Generation Satellite Precipitation Products for Understanding Global and Regional Water Variability

    Science.gov (United States)

    Hou, Arthur Y.

    2011-01-01

    A major challenge in understanding the space-time variability of continental water fluxes is the lack of accurate precipitation estimates over complex terrains. While satellite precipitation observations can be used to complement ground-based data to obtain improved estimates, space-based and ground-based estimates come with their own sets of uncertainties, which must be understood and characterized. Quantitative estimation of uncertainties in these products also provides a necessary foundation for merging satellite and ground-based precipitation measurements within a rigorous statistical framework. Global Precipitation Measurement (GPM) is an international satellite mission that will provide next-generation global precipitation data products for research and applications. It consists of a constellation of microwave sensors provided by NASA, JAXA, CNES, ISRO, EUMETSAT, DOD, NOAA, NPP, and JPSS. At the heart of the mission is the GPM Core Observatory provided by NASA and JAXA to be launched in 2013. The GPM Core, which will carry the first space-borne dual-frequency radar and a state-of-the-art multi-frequency radiometer, is designed to set new reference standards for precipitation measurements from space, which can then be used to unify and refine precipitation retrievals from all constellation sensors. The next-generation constellation-based satellite precipitation estimates will be characterized by intercalibrated radiometric measurements and physical-based retrievals using a common observation-derived hydrometeor database. For pre-launch algorithm development and post-launch product evaluation, NASA supports an extensive ground validation (GV) program in cooperation with domestic and international partners to improve (1) physics of remote-sensing algorithms through a series of focused field campaigns, (2) characterization of uncertainties in satellite and ground-based precipitation products over selected GV testbeds, and (3) modeling of atmospheric processes and

  11. Consistency analysis of the water cycle from recently derived satellite products

    Science.gov (United States)

    Berbery, E. H.; Hain, C.; Anderson, M. C.; Zhan, X.; Liu, J.; Ferraro, R. R.; Adler, R. F.; Wu, H.

    2015-12-01

    NOAA's National Environmental Satellite, Data, and Information Service (NESDIS) develops environmental data from satellites and other sources that is a critical resource for the management of energy, water, and food supplies. Variables related to the water cycle are routinely computed from satellite remote sensing from several space agencies, and the products are used at NOAA in operational or experimental modes. This study seeks to investigate to what extent there is consistency among the diverse products, and how they represent the water cycle at different scales. Remote sensing of land surface temperature and radiation is used to estimate surface energy fluxes by means of the Atmosphere Land Exchange Inverse (ALEXI) model. An Evaporative Stress Index representing anomalies in the ratio of actual-to-potential is a reliable indicator of drought also obtained from the ALEXI model. Observations from all currently available microwave satellite sensors are processed and merged to obtain the best possible estimates of soil moisture. The Global Soil Moisture Operational Product System (SMOPS) may also ingest brightness temperature observations applying a single channel algorithm to retrieve soil moisture. All satellite retrievals in SMOPS are merged into a soil moisture product that includes proxies of the errors. The Global Precipitation Climatology Project (GPCP) monthly precipitation data set (a current NOAA CDR project) uses satellite precipitation data sets over ocean and satellite plus gauge-based analyses over land. For operational needs, NESDIS's Hydro-Estimator (H-E) uses infrared data from GOES to estimate higher temporal resolution (sub-daily) rainfall rates. Streamflow at all the river mouths is estimated by the Dominant river tracing-Routing Integrated with VIC Environment model using precipitation input and other forcing data. Evapotranspiration, soil moisture, precipitation, streamflow and groundwater are derived at different resolutions, time scales and

  12. Depiction of global drought by reanalysis and real-time satellite precipitation products

    Science.gov (United States)

    Wood, Eric; Zhan, Wang

    2017-04-01

    Reanalysis precipitation is routinely used as a surrogate of observations due to its high spatial and temporal resolution and global coverage, and thus widely used in hydrologic and agricultural applications. The resultant product is largely dependent on the accuracy of reanalysis precipitation datasets. With advances in satellite remote sensing technology, the latest generation of reanalysis systems starts to include real time satellite precipitation estimates as inputs to their assimilation system. In this presentation, reanalysis precipitations datasets and real-time satellite rainfall products are used for the depiction of global drought events by comparing them against an observational reference dataset, namely the Princeton Global Forcing (PGF) dataset, during the period of March 2000 to December 2012. The selected reanalyses are the Climate Forecast System Reanalysis (CFSR), ERA-Interim, and the Modern-Era Retrospective Analysis for Research and Applications, version 1 (MERRA) and 2 (MERRA-2). Three real-time satellite precipitation estimates; namely the Tropical Rainfall Measuring Mission (TRMM) Multi-Satellite Precipitation Analysis (TMPA) 3B42RT, the Climate Prediction Center (CPC) morphing algorithm (CMORPH) and the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) are included in the study. Our results show that all datasets depict Sub-Saharan African drought events with limited skill, as opposed to mid latitude regions. Reanalyses and satellite real-time precipitation datasets have comparative skill in the low latitudes. Specific drought events are analyzed that demonstrate the drought depiction from the various datasets. In North America, Asia and Europe, drought events are better replicated and inter-dataset variability is significantly smaller. Overall, temporal characteristics of identified drought events are better estimated than their spatial extent.

  13. Utilization of Precipitation and Moisture Products Derived from Satellites to Support NOAA Operational Precipitation Forecasts

    Science.gov (United States)

    Ferraro, R.; Zhao, L.; Kuligowski, R. J.; Kusselson, S.; Ma, L.; Kidder, S. Q.; Forsythe, J. M.; Jones, A. S.; Ebert, E. E.; Valenti, E.

    2012-12-01

    NOAA/NESDIS operates a constellation of polar and geostationary orbiting satellites to support weather forecasts and to monitor the climate. Additionally, NOAA utilizes satellite assets from other U.S. agencies like NASA and the Department of Defense, as well as those from other nations with similar weather and climate responsibilities (i.e., EUMETSAT and JMA). Over the past two decades, through joint efforts between U.S. and international government researchers, academic partners, and private sector corporations, a series of "value added" products have been developed to better serve the needs of weather forecasters and to exploit the full potential of precipitation and moisture products generated from these satellites. In this presentation, we will focus on two of these products - Ensemble Tropical Rainfall Potential (eTRaP) and Blended Total Precipitable Water (bTPW) - and provide examples on how they contribute to hydrometeorological forecasts. In terms of passive microwave satellite products, TPW perhaps is most widely used to support real-time forecasting applications, as it accurately depicts tropospheric water vapor and its movement. In particular, it has proven to be extremely useful in determining the location, timing, and duration of "atmospheric rivers" which contribute to and sustain flooding events. A multi-sensor approach has been developed and implemented at NESDIS in which passive microwave estimates from multiple satellites and sensors are merged to create a seamless, bTPW product that is more efficient for forecasters to use. Additionally, this product is being enhanced for utilization for television weather forecasters. Examples will be shown to illustrate the roll of atmospheric rivers and contribution to flooding events, and how the bTPW product was used to improve the forecast of these events. Heavy rains associated with land falling tropical cyclones (TC) frequently trigger floods that cause millions of dollars of damage and tremendous loss

  14. The long-term Global LAnd Surface Satellite (GLASS) product suite and applications

    Science.gov (United States)

    Liang, S.

    2015-12-01

    Our Earth's environment is experiencing rapid changes due to natural variability and human activities. To monitor, understand and predict environment changes to meet the economic, social and environmental needs, use of long-term high-quality satellite data products is critical. The Global LAnd Surface Satellite (GLASS) product suite, generated at Beijing Normal University, currently includes 12 products, including leaf area index (LAI), broadband shortwave albedo, broadband longwave emissivity, downwelling shortwave radiation and photosynthetically active radiation, land surface skin temperature, longwave net radiation, daytime all-wave net radiation, fraction of absorbed photosynetically active radiation absorbed by green vegetation (FAPAR), fraction of green vegetation coverage, gross primary productivity (GPP), and evapotranspiration (ET). Most products span from 1981-2014. The algorithms for producing these products have been published in the top remote sensing related journals and books. More and more applications have being reported in the scientific literature. The GLASS products are freely available at the Center for Global Change Data Processing and Analysis of Beijing Normal University (http://www.bnu-datacenter.com/), and the University of Maryland Global Land Cover Facility (http://glcf.umd.edu). After briefly introducing the basic characteristics of GLASS products, we will present some applications on the long-term environmental changes detected from GLASS products at both global and local scales. Detailed analysis of regional hotspots, such as Greenland, Tibetan plateau, and northern China, will be emphasized, where environmental changes have been mainly associated with climate warming, drought, land-atmosphere interactions, and human activities.

  15. Measurement of productive efficiency with frontier methods: A case study for wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, Guillermo, E-mail: gwig@udc.e [Facultad de Ciencias Economicas y Empresariales, Departamento de Economia Aplicada I, Universidad de A Coruna, Campus de Elvina s/n, 15071 A Coruna (Spain); Castellanos, Pablo, E-mail: pcg@udc.e [Facultad de Ciencias Economicas y Empresariales, Departamento de Economia Aplicada I, Universidad de A Coruna, Campus de Elvina s/n, 15071 A Coruna (Spain); Seijas, Amparo, E-mail: asdeai@udc.e [Facultad de Ciencias Economicas y Empresariales, Departamento de Economia Aplicada I, Universidad de A Coruna, Campus de Elvina s/n, 15071 A Coruna (Spain)

    2010-09-15

    In this paper, we measure the productive efficiency of a group of wind farms during the period 2001-2004 using the frontier methods Data Envelopment Analysis (DEA) and Stochastic Frontier Analysis (SFA). Taking an extensive definition of the productive process of wind electricity as our starting point, we obtain results which allow us to identify, on the one hand, an essentially ex ante efficiency measure and, on the other hand, aspects of relevance for wind farm development companies (developers), technology suppliers and operators in terms of their economic impact. These results may also be of interest for regulators and other stakeholders in the sector. Furthermore, we discuss the implications of the simultaneous use of DEA and SFA methodologies.

  16. Measurement of productive efficiency with frontier methods. A case study for wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, Guillermo; Castellanos, Pablo; Seijas, Amparo [Facultad de Ciencias Economicas y Empresariales, Departamento de Economia Aplicada I, Universidad de A Coruna, Campus de Elvina s/n, 15071 A Coruna (Spain)

    2010-09-15

    In this paper, we measure the productive efficiency of a group of wind farms during the period 2001-2004 using the frontier methods Data Envelopment Analysis (DEA) and Stochastic Frontier Analysis (SFA). Taking an extensive definition of the productive process of wind electricity as our starting point, we obtain results which allow us to identify, on the one hand, an essentially ex ante efficiency measure and, on the other hand, aspects of relevance for wind farm development companies (developers), technology suppliers and operators in terms of their economic impact. These results may also be of interest for regulators and other stakeholders in the sector. Furthermore, we discuss the implications of the simultaneous use of DEA and SFA methodologies. (author)

  17. Evaluation of Satellite and Ground Based Precipitation Products for Flood Forecasting

    Science.gov (United States)

    Chintalapudi, S.; Sharif, H.; Yeggina, S.

    2012-04-01

    The development in satellite-derived rainfall estimates encouraged the hydrological modeling in sparse gauged basins or ungauged basins. Especially, physically-based distributed hydrological models can benefit from the good spatial and temporal coverage of satellite precipitation products. In this study, three satellite derived precipitation datasets (TRMM, CMORPH, and PERSIANN), NEXRAD, and rain gauge precipitation datasets were used to drive the hydrological model. The physically-based, distributed hydrological model Gridded Surface Subsurface Hydrological Analysis (GSSHA) was used in this study. Focus will be on the results from the Guadalupe River Basin above Canyon Lake and below Comfort, Texas. The Guadalupe River Basin above Canyon Lake and below Comfort Texas drains an area of 1232 km2. Different storm events will be used in these simulations. August 2007 event was used as calibration and June 2007 event was used as validation. Results are discussed interms of accuracy of satellite precipitation estimates with the ground based precipitation estimates, predicting peak discharges, runoff volumes, time lag, and spatial distribution. The initial results showed that, model was able to predict the peak discharges and runoff volumes when using NEXRAD MPE data, and TRMM 3B42 precipitation product. The results also showed that there was time lag in hydrographs driven by both PERSIANN and CMORPH data sets.

  18. Evaluating a satellite-based seasonal evapotranspiration product and identifying its relationship with other satellite-derived products and crop yield: A case study for Ethiopia

    Science.gov (United States)

    Tadesse, Tsegaye; Senay, Gabriel B.; Berhan, Getachew; Regassa, Teshome; Beyene, Shimelis

    2015-01-01

    Satellite-derived evapotranspiration anomalies and normalized difference vegetation index (NDVI) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data are currently used for African agricultural drought monitoring and food security status assessment. In this study, a process to evaluate satellite-derived evapotranspiration (ETa) products with a geospatial statistical exploratory technique that uses NDVI, satellite-derived rainfall estimate (RFE), and crop yield data has been developed. The main goal of this study was to evaluate the ETa using the NDVI and RFE, and identify a relationship between the ETa and Ethiopia’s cereal crop (i.e., teff, sorghum, corn/maize, barley, and wheat) yields during the main rainy season. Since crop production is one of the main factors affecting food security, the evaluation of remote sensing-based seasonal ETa was done to identify the appropriateness of this tool as a proxy for monitoring vegetation condition in drought vulnerable and food insecure areas to support decision makers. The results of this study showed that the comparison between seasonal ETa and RFE produced strong correlation (R2 > 0.99) for all 41 crop growing zones in Ethiopia. The results of the spatial regression analyses of seasonal ETa and NDVI using Ordinary Least Squares and Geographically Weighted Regression showed relatively weak yearly spatial relationships (R2 cropping zones. However, for each individual crop zones, the correlation between NDVI and ETa ranged between 0.3 and 0.84 for about 44% of the cropping zones. Similarly, for each individual crop zones, the correlation (R2) between the seasonal ETa anomaly and de-trended cereal crop yield was between 0.4 and 0.82 for 76% (31 out of 41) of the crop growing zones. The preliminary results indicated that the ETa products have a good predictive potential for these 31 identified zones in Ethiopia. Decision makers may potentially use ETa products for monitoring cereal crop yields and

  19. Near-real-time global biomass burning emissions product from geostationary satellite constellation

    Science.gov (United States)

    Zhang, Xiaoyang; Kondragunta, Shobha; Ram, Jessica; Schmidt, Christopher; Huang, Ho-Chun

    2012-07-01

    Near-real-time estimates of biomass burning emissions are crucial for air quality monitoring and forecasting. We present here the first near-real-time global biomass burning emission product from geostationary satellites (GBBEP-Geo) produced from satellite-derived fire radiative power (FRP) for individual fire pixels. Specifically, the FRP is retrieved using WF_ABBA V65 (wildfire automated biomass burning algorithm) from a network of multiple geostationary satellites. The network consists of two Geostationary Operational Environmental Satellites (GOES) which are operated by the National Oceanic and Atmospheric Administration, the Meteosat second-generation satellites (Meteosat-09) operated by the European Organisation for the Exploitation of Meteorological Satellites, and the Multifunctional Transport Satellite (MTSAT) operated by the Japan Meteorological Agency. These satellites observe wildfires at an interval of 15-30 min. Because of the impacts from sensor saturation, cloud cover, and background surface, the FRP values are generally not continuously observed. The missing observations are simulated by combining the available instantaneous FRP observations within a day and a set of representative climatological diurnal patterns of FRP for various ecosystems. Finally, the simulated diurnal variation in FRP is applied to quantify biomass combustion and emissions in individual fire pixels with a latency of 1 day. By analyzing global patterns in hourly biomass burning emissions in 2010, we find that peak fire season varied greatly and that annual wildfires burned 1.33 × 1012 kg dry mass, released 1.27 × 1010 kg of PM2.5 (particulate mass for particles with diameter forest and savanna fires in Africa, South America, and North America. Evaluation of emission result reveals that the GBBEP-Geo estimates are comparable with other FRP-derived estimates in Africa, while the results are generally smaller than most of the other global products that were derived from burned

  20. Satellite Derived Volcanic Ash Product Inter-Comparison in Support to SCOPE-Nowcasting

    Science.gov (United States)

    Siddans, Richard; Thomas, Gareth; Pavolonis, Mike; Bojinski, Stephan

    2016-04-01

    In support of aeronautical meteorological services, WMO organized a satellite-based volcanic ash retrieval algorithm inter-comparison activity, to improve the consistency of quantitative volcanic ash products from satellites, under the Sustained, Coordinated Processing of Environmental Satellite Data for Nowcasting (SCOPEe Nowcasting) initiative (http:/ jwww.wmo.int/pagesjprogjsatjscopee nowcasting_en.php). The aims of the intercomparison were as follows: 1. Select cases (Sarychev Peak 2009, Eyjafyallajökull 2010, Grimsvötn 2011, Puyehue-Cordón Caulle 2011, Kirishimayama 2011, Kelut 2014), and quantify the differences between satellite-derived volcanic ash cloud properties derived from different techniques and sensors; 2. Establish a basic validation protocol for satellite-derived volcanic ash cloud properties; 3. Document the strengths and weaknesses of different remote sensing approaches as a function of satellite sensor; 4. Standardize the units and quality flags associated with volcanic cloud geophysical parameters; 5. Provide recommendations to Volcanic Ash Advisory Centers (VAACs) and other users on how to best to utilize quantitative satellite products in operations; 6. Create a "road map" for future volcanic ash related scientific developments and inter-comparison/validation activities that can also be applied to SO2 clouds and emergent volcanic clouds. Volcanic ash satellite remote sensing experts from operational and research organizations were encouraged to participate in the inter-comparison activity, to establish the plans for the inter-comparison and to submit data sets. RAL was contracted by EUMETSAT to perform a systematic inter-comparison of all submitted datasets and results were reported at the WMO International Volcanic Ash Inter-comparison Meeting to held on 29 June - 2 July 2015 in Madison, WI, USA (http:/ /cimss.ssec.wisc.edujmeetings/vol_ash14). 26 different data sets were submitted, from a range of passive imagers and spectrometers and

  1. Intercomparison of Several Ocean Surface Wind Products over the Nordic Seas

    Science.gov (United States)

    Dukhovskoy, Dmitry; Bourassa, Mark

    2014-05-01

    Surface winds are one of the key parameters that control the exchange of energy between the atmosphere and oceans. Being the major source of momentum for the upper ocean, winds mainly control ocean processes and air-sea interaction especially in synoptically active regions such as the Nordic Seas (Greenland, Norwegian, Iceland, and Barents Seas). Intense formation of water masses takes place in the Nordic Seas through cooling, brine rejection, and mixing of Arctic Ocean and North Atlantic waters. Deep water produced in this region by deep convection participates in the Atlantic Meridional Overturning Circulation. Water masses formed in the Nordic Seas are also important for the maintenance of thermohaline structure of the Arctic Ocean. The Nordic Seas has always been a challenging region for Arctic Ocean modeling due to complex ocean circulation, water mass transformation, intense air-sea interaction, deep vertical convection, etc. The lack of reliable high-resolution wind products over the Polar region is another factor that has been impacting modeling of the Arctic Ocean in general and the Nordic Seas in particular. Coarse resolution atmospheric fields are often used to force the Arctic Ocean models. The major drawback of the coarse resolution wind products is their inability to resolve small- and meso-scale cyclones frequently impacting the Nordic Seas. Several gridded surface wind products derived from scatterometer wind observations have reasonably high spatial resolution to represent most of the small scale cyclones in the region. In the present model study, Cross-Calibrated Multi-Platform surface wind data (CCMP) are compared against the wind fields from traditional the NCEP/NCAR Reanalysis 2 (NCEPR), from NCEP Climate Forecast System Reanalysis (CFSR), and from the interium version (30km) of the Arctic System Reanalysis (ASR). The NCEPR is a coarse resolution product (1.9°) and still is the primary source of forcing fields for the Arctic Ocean models. The

  2. Assessment and Comparison of TMPA Satellite Precipitation Products in Varying Climatic and Topographic Regimes in Morocco

    Directory of Open Access Journals (Sweden)

    Adam Milewski

    2015-05-01

    Full Text Available TRMM Multi-satellite Precipitation Analysis (TMPA satellite precipitation products have been utilized to quantify, forecast, or understand precipitation patterns, climate change, hydrologic models, and drought in numerous scientific investigations. The TMPA products recently went through a series of algorithm developments to enhance the accuracy and reliability of high-quality precipitation measurements, particularly in low rainfall environments and complex terrain. In this study, we evaluated four TMPA products (3B42: V6, V7temp, V7, RTV7 against 125 rain gauges in Northern Morocco to assess the accuracy of TMPA products in various regimes, examine the performance metrics of new algorithm developments, and assess the impact of the processing error in 2012. Results show that the research products outperform the real-time products in all environments within Morocco, and the newest algorithm development (3B42 V7 outperforms the previous version (V6, particularly in low rainfall and high-elevation environments. TMPA products continue to overestimate precipitation in arid environments and underestimate it in high-elevation areas. Lastly, the temporary processing error resulted in little bias except in arid environments. These results corroborate findings from previous studies, provide scientific data for the Middle East, highlight the difficulty of using TMPA products in varying conditions, and present preliminary research for future algorithm development for the GPM mission.

  3. Reliability Measures of Second-Order Semi-Markov Chain Applied to Wind Energy Production

    Directory of Open Access Journals (Sweden)

    Guglielmo D'Amico

    2013-01-01

    Full Text Available We consider the problem of wind energy production by using a second-order semi-Markov chain in state and duration as a model of wind speed. The model used in this paper is based on our previous work where we have shown the ability of second-order semi-Markov process in reproducing statistical features of wind speed. Here we briefly present the mathematical model and describe the data and technical characteristics of a commercial wind turbine (Aircon HAWT-10 kW. We show how, by using our model, it is possible to compute some of the main dependability measures such as reliability, availability, and maintainability functions. We compare, by means of Monte Carlo simulations, the results of the model with real energy production obtained from data available in the Lastem station (Italy and sampled every 10 minutes. The computation of the dependability measures is a crucial point in the planning and development of a wind farm. Through our model, we show how the values of this quantity can be obtained both analytically and computationally.

  4. Effects of sea ice cover on satellite-detected primary production in the Arctic Ocean.

    Science.gov (United States)

    Kahru, Mati; Lee, Zhongping; Mitchell, B Greg; Nevison, Cynthia D

    2016-11-01

    The influence of decreasing Arctic sea ice on net primary production (NPP) in the Arctic Ocean has been considered in multiple publications but is not well constrained owing to the potentially large errors in satellite algorithms. In particular, the Arctic Ocean is rich in coloured dissolved organic matter (CDOM) that interferes in the detection of chlorophyll a concentration of the standard algorithm, which is the primary input to NPP models. We used the quasi-analytic algorithm (Lee et al 2002 Appl. Opti. 41, 5755-5772. (doi:10.1364/AO.41.005755)) that separates absorption by phytoplankton from absorption by CDOM and detrital matter. We merged satellite data from multiple satellite sensors and created a 19 year time series (1997-2015) of NPP. During this period, both the estimated annual total and the summer monthly maximum pan-Arctic NPP increased by about 47%. Positive monthly anomalies in NPP are highly correlated with positive anomalies in open water area during the summer months. Following the earlier ice retreat, the start of the high-productivity season has become earlier, e.g. at a mean rate of -3.0 d yr(-1) in the northern Barents Sea, and the length of the high-productivity period has increased from 15 days in 1998 to 62 days in 2015. While in some areas, the termination of the productive season has been extended, owing to delayed ice formation, the termination has also become earlier in other areas, likely owing to limited nutrients.

  5. Technologies for production of Electricity and Heat in Sweden. Wind energy in perspective of international development

    DEFF Research Database (Denmark)

    Clausen, Niels-Erik; Lawaetz, Henrik; Lemming, Jørgen Kjærgaard

    energy consumption in 2020 compared to 39.8% in 2005. To stimulate the development of wind energy and to promote a specific national goals Sweden is mainly using an electricity certificate system. The target is to increase the production of electricity from renewable sources by 17 TWh in 2016, relative...

  6. SYSTEM AND PROCESS FOR PRODUCTION OF METHANOL FROM COMBINED WIND TURBINE AND FUEL CELL POWER

    Science.gov (United States)

    The paper examines an integrated use of ultra-clean wind turbines and high temperature fuel cells to produce methanol, especially for transportation purposes. The principal utility and application of the process is the production of transportation fuel from domestic resources to ...

  7. SYSTEM AND PROCESS FOR PRODUCTION OF METHANOL FROM COMBINED WIND TURBINE AND FUEL CELL POWER

    Science.gov (United States)

    The paper examines an integrated use of ultra-clean wind turbines and high temperature fuel cells to produce methanol, especially for transportation purposes. The principal utility and application of the process is the production of transportation fuel from domestic resources to ...

  8. Wind Tunnel Evaluation of Vegetative Buffer Effects on Air Flow near Swine Production Facilities

    Science.gov (United States)

    Increasing concerns about generation and transport of swine odor constituents have substantiated wind tunnel simulation studies on air flow dynamics near swine production facilities. A possible odor mitigation strategy is a forest vegetative buffer as a windbreak barrier near swine facilities becaus...

  9. Spatial Trade-Offs between Wind Power Production and Bird Collision Avoidance in Agricultural Landscapes

    Directory of Open Access Journals (Sweden)

    Martin Drechsler

    2010-06-01

    Full Text Available The expansion of renewable energy production is seen as an appropriate way to mitigate climate change. Renewable energies are not free of negative external effects on humans and the natural environment. We analyzed the conflict between wind power production and bird protection through the example of one of the most sensitive species, the red kite (Milvus milvus in West Saxony, Germany. We investigated a large number of potential land use scenarios, defined by whether or not each potential site contained a wind turbine (WT. Based on meteorological and ornithological data, we evaluated the land use scenarios for their annual energy supply and impact on the red kite. We identified the efficient land use scenarios that maximized energy supply for a given ecological impact. Within the scope of our analysis, the current allocation of WTs in the study region was considered inefficient. The set of efficient scenarios allowed us to draw conclusions on the trade-offs involved. We developed an indicator that measures the severity of the conflict between wind power production and bird protection. Increasing the minimum distance of WTs to settlements beyond the legal requirements in order to minimize the impact on humans further intensifies the conflict. Our results can support planning authorities in their development of long-term regional plans by identifying areas that are most suitable for wind power production from an integrated point of view.

  10. CryoSat-2 Wind and Wave Products: Monitoring, Validation and Assimilation

    Science.gov (United States)

    Abdalla, Saleh; Janssen, Peter; Bidlot, Jean-Raymond

    2016-08-01

    The Fast Delivery Marine Mode (FDM) wind and wave data from CryoSat-2 radar altimeter instrument SIRAL are made available by ESA. Significant wave height and surface wind speed and its basic ingredient the altimeter backscatter are routinely monitored and validated at ECMWF. Model fields, in-situ observations and measurements from other altimeters are used for this purpose. In general, the CryoSat-2 FDM wind and wave products are of good quality. However, the wind speed product is about 1 m/s higher than the model and what other instruments (in-situ, and other altimeters). It is also about 15% noisier than the other sources. On the other hand, the SWH product is very good. However, the product may need minor adjustment at low wave heights. The timeliness of data delivery is quite good with most of the data are received within 1 hour (of the end of the 6-hour time window). Assimilating the CryoSat-2 SWH in the ECMWF Integrated Forecast System proved to have a good impact on the model analysis and forecasts. Operational assimilation of SWH at ECMWF model was realised in May 2015.

  11. Offshore wind resource estimation for wind energy

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Mouche, A.

    2010-01-01

    Satellite remote sensing from active and passive microwave instruments is used to estimate the offshore wind resource in the Northern European Seas in the EU-Norsewind project. The satellite data include 8 years of Envisat ASAR, 10 years of QuikSCAT, and 23 years of SSM/I. The satellite...... observations are compared to selected offshore meteorological masts in the Baltic Sea and North Sea. The overall aim of the Norsewind project is a state-of-the-art wind atlas at 100 m height. The satellite winds are all valid at 10 m above sea level. Extrapolation to higher heights is a challenge. Mesoscale...... modeling of the winds at hub height will be compared to data from wind lidars observing at 100 m above sea level. Plans are also to compare mesoscale model results and satellite-based estimates of the offshore wind resource....

  12. The flow upstream of a row of aligned wind turbine rotors and its effect on power production

    DEFF Research Database (Denmark)

    Meyer Forsting, Alexander Raul; Troldborg, Niels; Gaunaa, Mac

    2017-01-01

    The blockage developing in front of a laterally aligned row of wind turbines and its impact on power production over a single turbine was analysed using two different numerical methods. The inflow direction was varied from orthogonal to the row until 45◦, with the turbines turning into the wind......, thereby resembling a wind turbine testing site or row in a wind park. The numerical methods included computational fluid dynamics (CFD) with an actuator disc representation of the rotor and a simple vortex method. The forces on the actuator disc were either derived from airfoil data of a modern wind...

  13. Brilliance Auto:Independent Quality Product "China Wind"

    Institute of Scientific and Technical Information of China (English)

    Bai Yifeng; Liu Jinliang

    2006-01-01

    @@ Brilliance Auto, leads one and another leap of Chinese automobile with its unique posture of "high starting point independent innovation". As the new vigor power of national automobile, "forge national independent brand quality product" is the pursuit of Brilliance Auto since a long time.

  14. Evaluating Satellite Products for Precipitation Estimation in Mountain Regions: A Case Study for Nepal

    Directory of Open Access Journals (Sweden)

    Tarendra Lakhankar

    2013-08-01

    Full Text Available Precipitation in mountain regions is often highly variable and poorly observed, limiting abilities to manage water resource challenges. Here, we evaluate remote sensing and ground station-based gridded precipitation products over Nepal against weather station precipitation observations on a monthly timescale. We find that the Tropical Rainfall Measuring Mission (TRMM 3B-43 precipitation product exhibits little mean bias and reasonable skill in giving precipitation over Nepal. Compared to station observations, the TRMM precipitation product showed an overall Nash-Sutcliffe efficiency of 0.49, which is similar to the skill of the gridded station-based product Asian Precipitation-Highly Resolved Observational Data Integration Towards Evaluation of Water Resources (APHRODITE. The other satellite precipitation products considered (Global Satellite Mapping of Precipitation (GSMaP, the Climate Prediction Center Morphing technique (CMORPH, Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS were less skillful, as judged by Nash-Sutcliffe efficiency, and, on average, substantially underestimated precipitation compared to station observations, despite their, in some cases, higher nominal spatial resolution compared to TRMM. None of the products fully captured the dependence of mean precipitation on elevation seen in the station observations. Overall, the TRMM product is promising for use in water resources applications.

  15. The Global Land Surface Satellite (GLASS Remote Sensing Data Processing System and Products

    Directory of Open Access Journals (Sweden)

    Gongqi Zhou

    2013-05-01

    Full Text Available Using remotely sensed satellite products is the most efficient way to monitor global land, water, and forest resource changes, which are believed to be the main factors for understanding global climate change and its impacts. A reliable remotely sensed product should be retrieved quantitatively through models or statistical methods. However, producing global products requires a complex computing system and massive volumes of multi-sensor and multi-temporal remotely sensed data. This manuscript describes the ground Global LAnd Surface Satellite (GLASS product generation system that can be used to generate long-sequence time series of global land surface data products based on various remotely sensed data. To ensure stabilization and efficiency in running the system, we used the methods of task management, parallelization, and multi I/O channels. An array of GLASS remote sensing products related to global land surface parameters are currently being produced and distributed by the Center for Global Change Data Processing and Analysis at Beijing Normal University in Beijing, China. These products include Leaf Area Index (LAI, land surface albedo, and broadband emissivity (BBE from the years 1981 to 2010, downward shortwave radiation (DSR and photosynthetically active radiation (PAR from the years 2008 to 2010.

  16. Evaluation of Satellite Precipitation Products with Rain Gauge Data at Different Scales: Implications for Hydrological Applications

    Directory of Open Access Journals (Sweden)

    Ruifang Guo

    2016-07-01

    Full Text Available Rain gauge and satellite-retrieved data have been widely used in basin-scale hydrological applications. While rain gauges provide accurate measurements that are generally unevenly distributed in space, satellites offer spatially regular observations and common error prone retrieval. Comparative evaluation of gauge-based and satellite-based data is necessary in hydrological studies, as precipitation is the most important input in basin-scale water balance. This study uses quality-controlled rain gauge data and prevailing satellite products (Tropical Rainfall Measuring Mission (TRMM 3B43, 3B42 and 3B42RT to examine the consistency and discrepancies between them at different scales. Rain gauges and TRMM products were available in the Poyang Lake Basin, China, from 1998 to 2007 (3B42RT: 2000–2007. Our results show that the performance of TRMM products generally increases with increasing spatial scale. At both the monthly and annual scales, the accuracy is highest for TRMM 3B43, with 3B42 second and 3B42RT third. TRMM products generally overestimate precipitation because of a high frequency and degree of overestimation in light and moderate rain cases. At the daily scale, the accuracy is relatively low between TRMM 3B42 and 3B42RT. Meanwhile, the performances of TRMM 3B42 and 3B42RT are highly variable in different seasons. At both the basin and pixel scales, TRMM 3B43 and 3B42 exhibit significant discrepancies from July to September, performing worst in September. For TRMM 3B42RT, all statistical indices fluctuate and are low throughout the year, performing worst in July at the pixel scale and January at the basin scale. Furthermore, the spatial distributions of the statistical indices of TRMM 3B43 and 3B42 performed well, while TRMM 3B42RT displayed a poor performance.

  17. A Mapping Approach for Large Area Wind Farm Based on Geoeye-1 Satellite Stereo Images%基于GeoEye-1立体像对的风电场大范围地形测量方法

    Institute of Scientific and Technical Information of China (English)

    张雅楠; 宋志勇

    2013-01-01

    Based on Geoeye-1 satellite stereo images,the mapping works for a wind farm which covers 200 square kilometers area in Huan County,Gansu province have been completed in this paper.A new fast and efficient way is provided for the large area surveying of wind power project.Compared with traditional methods,the new mapping approach would satisfy the demand of wind power projects for the tight schedule and large area.The mapping accuracy of this method is between 1∶2000 scale and 1:5000 scale.Meanwhile,high resolution DOM and high precision DEM can also be provided for the wind farm design.The digital productions can meet the demands of design changing and reduce the engineering cost.%基于Geoeye-1卫星影像立体像对完成了甘肃环县地区某风电场约200km2的测图工作,为风力发电项目大范围地形测量提供了一种新的快速高效的作业模式.相较于传统测量方法,该作业模式能够更好地满足风力发电项目测图范围大、设计工期紧的需求,成图精度介于1∶2000比例尺测图及1∶5000比例尺测图之间,并可提供高分辨率的DOM及高精度的DEM产品,更好地辅助风电场设计.其提供的大范围地形,可极大程度地满足设计变更的需要,降低工程成本.

  18. Validation of Satellite-Derived Land Surface Temperature Products - Methods and Good Practice

    Science.gov (United States)

    Guillevic, P. C.; Hulley, G. C.; Hook, S. J.; Biard, J.; Ghent, D.

    2014-12-01

    Land Surface Temperature (LST) is a key variable for surface water and energy budget calculations that can be obtained globally and operationally from satellite observations. LST is used for many applications, including weather forecasting, short-term climate prediction, extreme weather monitoring, and irrigation and water resource management. In order to maximize the usefulness of LST for research and studies it is necessary to know the uncertainty in the LST measurement. Multiple validation methods and activities are necessary to assess LST compliance with the quality specifications of operational users. This work presents four different validation methods that have been widely used to determine the uncertainties in LST products derived from satellite measurements. 1) The temperature based validation method involves comparisons with ground-based measurements of LST. The method is strongly limited by the number and quality of available field stations. 2) Scene-based comparisons involve comparing a new satellite LST product with a heritage LST product. This method is not an absolute validation and satellite LST inter-comparisons alone do not provide an independent validation measurement. 3) The radiance-based validation method does not require ground-based measurements and is usually used for large scale validation effort or for LST products with coarser spatial resolution (> 1km). 4) Time series comparisons are used to detect problems that can occur during the instrument's life, e.g. calibration drift, or unrealistic outliers due to cloud coverage. This study enumerates the sources of errors associated with each method. The four different approaches are complementary and provide different levels of information about the quality of the retrieved LST. The challenges in retrieving the LST from satellite measurements are discussed using results obtained for MODIS and VIIRS. This work contributes to the objective of the Land Product Validation (LPV) sub-group of the

  19. A cyclic time-dependent Markov process to model daily patterns in wind turbine power production

    CERN Document Server

    Scholz, Teresa; Estanqueiro, Ana

    2013-01-01

    Wind energy is becoming a top contributor to the renewable energy mix, which raises potential reliability issues for the grid due to the fluctuating nature of its source. To achieve adequate reserve commitment and to promote market participation, it is necessary to provide models that can capture daily patterns in wind power production. This paper presents a cyclic inhomogeneous Markov process, which is based on a three-dimensional state-space (wind power, speed and direction). Each time-dependent transition probability is expressed as a Bernstein polynomial. The model parameters are estimated by solving a constrained optimization problem: The objective function combines two maximum likelihood estimators, one to ensure that the Markov process long-term behavior reproduces the data accurately and another to capture daily fluctuations. A convex formulation for the overall optimization problem is presented and its applicability demonstrated through the analysis of a case-study. The proposed model is capable of r...

  20. Technoeconomic analysis of different options for the production of hydrogen from sunlight, wind, and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Mann, M.K.; Spath, P.L.; Amos, W.A. [National Renewable Energy Lab., Golden, CO (United States)

    1998-08-01

    To determine their technical and economic viability and to provide insight into where each technology is in its development cycle, different options to produce hydrogen from sunlight, wind, and biomass were studied. Additionally, costs for storing and transporting hydrogen were determined for different hydrogen quantities and storage times. The analysis of hydrogen from sunlight examined the selling price of hydrogen from two technologies: direct photoelectrochemical (PEC) conversion of sunlight and photovoltaic (PV)-generated electricity production followed by electrolysis. The wind analysis was based on wind-generated electricity production followed by electrolysis. In addition to the base case analyses, which assume that hydrogen is the sole product, three alternative scenarios explore the economic impact of integrating the PV- and wind-based systems with the electric utility grid. Results show that PEC hydrogen production has the potential to be economically feasible. Additionally, the economics of the PV and wind electrolysis systems are improved by interaction with the grid. The analysis of hydrogen from biomass focused on three gasification technologies. The systems are: low pressure, indirectly-heated gasification followed by steam reforming; high pressure, oxygen-blown gasification followed by steam reforming; and pyrolysis followed by partial oxidation. For each of the systems studied, the downstream process steps include shift conversion followed by hydrogen purification. Only the low pressure system produces hydrogen within the range of the current industry selling prices (typically $0.7--$2/kg, or $5--14/GJ on a HHV basis). A sensitivity analysis showed that, for the other two systems, in order to bring the hydrogen selling price down to $2/kg, negative-priced feedstocks would be required.

  1. Rapid generation of value added products for seismic crisis management, using ground and satellite data

    Science.gov (United States)

    Salvi, Stefano; Atzori, Simone; Pezzo, Giuseppe; Merryman Boncori, John Peter; Tolomei, Cristiano; Antonioli, Andrea; Trasatti, Elisa; Zoffoli, Simona; Coletta, Alessandro

    2013-04-01

    Rapid generation of value added products for seismic crisis management, using ground and satellite data Stefano Salvi (1), Simone Atzori (1), Giuseppe Pezzo (1), John Peter Merryman Boncori (1), Cristiano Tolomei (1), Andrea Antonioli (1), Elisa Trasatti (1), Simona Zoffoli (2), Alessandro Coletta (2) (1): Istituto Nazionale di Geofisica e Vulcanologia, Centro Nazionale Terremoti, via di Vigna Murata 605, 00143 Roma, Italy (2): Agenzia Spaziale Italiana, Unità Osservazione della Terra, Viale Liegi 26, 00198, Roma, Italy The increased availability of Earth Observation optical and SAR data occurred in the last few years, has stimulated new applications in many different fields. The foreseen launch of new space platforms as the Sentinel satellites, providing good monitoring frequencies and free worldwide access to data is expected to increase the number of scientific and commercial activities exploiting EO data. In the sector of natural hazards the EO data have already demonstrated to be indispensable for the generation of information products for the prevention, and emergency management phases. In particular, the Italian Space Agency has promoted and funded, together with INGV, the development of dedicated infrastructures for the generation of advanced information products supporting different phases of the seismic and volcanic risk management cycles. These products were based mainly on SAR data from the COSMO-SkyMed 4-satellite constellation, and on optical data from commercial and scientific platforms, integrated with data from ground monitoring networks. During the last few years, such infrastructures have been tested under operational conditions and the products distributed to the Italian Civil Protection authority for validation and assessment. Here, with reference to the earthquake emergency management, we will present the infrastructure, the rapid mapping information products and some examples of activities during the latest seismic crises.

  2. Methodology and forecast products for the optimal offering of ancillary services from wind in a market environment

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Pinson, Pierre

    of wind power for example in the planning of ancillary power services, where the level of available wind power with a high degree of certainty is important to know. The presented extreme value models are applied to negative forecast residuals from state-of-the-art wind power forecast software....... This enables the estimation of return levels below which the extreme wind power forecast error events occur only at a specified rate, e.g. once a month or once every year. The techniques allows extrapolation beyond the available data period. In the study data from 1.5 years is used. It consists of hourly wind...... power production in the two regions of Denmark (DK1 and DK2) and corresponding wind power forecasts. The wind power forecasts are generated using the software WPPT and are based on the outcome of three numerical weather prediction models. They cover horizons from 1 to 42 hours ahead in time...

  3. Comparison of special sensor microwave imager vector wind stress with model-derived and subjective products for the tropical Pacific

    Science.gov (United States)

    Busalacchi, Antonio J.; Atlas, Robert M.; Hackhert, Eric C.

    1993-01-01

    An assessment of a new source of vector wind stress data relative to existing analyses of the surface wind field is presented. The large-scale variability of vector wind stress generated by Atlas et al. (1991) and based on the special sensor microwave imager (SSM/I) remotely sensed observations of surface wind speed is compared with five operational and subjectively analyzed wind products across the tropical Pacific basin for the first year of SSM/I, July 1987 through June 1988. The spatial and temporal variability of the zonal component, meridional component, and curl of the wind stress are examined relative to their future use in wind-driven ocean model studies of tropical Pacific Ocean circulation.

  4. Comparison of special sensor microwave imager vector wind stress with model-derived and subjective products for the tropical Pacific

    Science.gov (United States)

    Busalacchi, Antonio J.; Atlas, Robert M.; Hackhert, Eric C.

    1993-01-01

    An assessment of a new source of vector wind stress data relative to existing analyses of the surface wind field is presented. The large-scale variability of vector wind stress generated by Atlas et al. (1991) and based on the special sensor microwave imager (SSM/I) remotely sensed observations of surface wind speed is compared with five operational and subjectively analyzed wind products across the tropical Pacific basin for the first year of SSM/I, July 1987 through June 1988. The spatial and temporal variability of the zonal component, meridional component, and curl of the wind stress are examined relative to their future use in wind-driven ocean model studies of tropical Pacific Ocean circulation.

  5. Assessing the performance of satellite-based precipitation products over the Mediterranean region

    Science.gov (United States)

    Xaver, Angelika; Dorigo, Wouter; Brocca, Luca; Ciabatta, Luca

    2017-04-01

    Detailed knowledge about the spatial and temporal patterns and quantities of precipitation is of high importance. This applies especially in the Mediterranean region, where water demand for agricultural, industrial and touristic needs is growing and climate projections foresee a decrease of precipitation amounts and an increase in variability. In this region, ground-based rain gauges are available only limited in number, particularly in northern Africa and the Middle East and lack to capture the high spatio-temporal character of precipitation over large areas. This has motivated the development of a large number of remote sensing products for monitoring rainfall. Satellite-based precipitation products are based on various observation principles and retrieval approaches, i.e. from thermal infra-red and microwaves. Although, many individual validation studies on the performance of these precipitation datasets exist, they mostly examine only one or a few of these rainfall products at the same time and are not targeted at the Mediterranean basin as a whole. Here, we present an extensive comparative study of seven different satellite-based precipitation products, namely CMORPH 30-minutes, CMORPH 3-hourly, GPCP, PERSIANN, SM2Rain CCI, TRMM TMPA 3B42, and TRMM TMPA 3B42RT, focusing on the whole Mediterranean region and on individual Mediterranean catchments. The time frame of investigation is restricted by the common availability of all precipitation products and covers the period 2000-2013. We assess the skill of the satellite products against gridded gauge-based data provided by GPCC and E-OBS. Apart from common characteristics like biases and temporal correlations we evaluate several sophisticated dataset properties that are of particular interest for Mediterranean hydrology, including the capability of the remotely sensed products to capture extreme events and trends. A clear seasonal dependency of the correlation results can be observed for the whole Mediterranean

  6. Online Tools for Uncovering Data Quality (DQ) Issues in Satellite-Based Global Precipitation Products

    Science.gov (United States)

    Liu, Zhong; Heo, Gil

    2015-01-01

    Data quality (DQ) has many attributes or facets (i.e., errors, biases, systematic differences, uncertainties, benchmark, false trends, false alarm ratio, etc.)Sources can be complicated (measurements, environmental conditions, surface types, algorithms, etc.) and difficult to be identified especially for multi-sensor and multi-satellite products with bias correction (TMPA, IMERG, etc.) How to obtain DQ info fast and easily, especially quantified info in ROI Existing parameters (random error), literature, DIY, etc.How to apply the knowledge in research and applications.Here, we focus on online systems for integration of products and parameters, visualization and analysis as well as investigation and extraction of DQ information.

  7. Hydrological Utility and Uncertainty of Multi-Satellite Precipitation Products in the Mountainous Region of South Korea

    Directory of Open Access Journals (Sweden)

    Jong Pil Kim

    2016-07-01

    Full Text Available Satellite-derived precipitation can be a potential source of forcing data for assessing water availability and managing water supply in mountainous regions of East Asia. This study investigates the hydrological utility of satellite-derived precipitation and uncertainties attributed to error propagation of satellite products in hydrological modeling. To this end, four satellite precipitation products (tropical rainfall measuring mission (TRMM multi-satellite precipitation analysis (TMPA version 6 (TMPAv6 and version 7 (TMPAv7, the global satellite mapping of precipitation (GSMaP, and the climate prediction center (CPC morphing technique (CMORPH were integrated into a physically-based hydrologic model for the mountainous region of South Korea. The satellite precipitation products displayed different levels of accuracy when compared to the intra- and inter-annual variations of ground-gauged precipitation. As compared to the GSMaP and CMORPH products, superior performances were seen when the TMPA products were used within streamflow simulations. Significant dry (negative biases in the GSMaP and CMORPH products led to large underestimates of streamflow during wet-summer seasons. Although the TMPA products displayed a good level of performance for hydrologic modeling, there were some over/underestimates of precipitation by satellites during the winter season that were induced by snow accumulation and snowmelt processes. These differences resulted in streamflow simulation uncertainties during the winter and spring seasons. This study highlights the crucial need to understand hydrological uncertainties from satellite-derived precipitation for improved water resource management and planning in mountainous basins. Furthermore, it is suggested that a reliable snowfall detection algorithm is necessary for the new global precipitation measurement (GPM mission.

  8. Assessing water availability over peninsular Malaysia using public domain satellite data products

    Science.gov (United States)

    Ali, M. I.; Hashim, M.; Zin, H. S. M.

    2014-02-01

    Water availability monitoring is an essential task for water resource sustainability and security. In this paper, the assessment of satellite remote sensing technique for determining water availability is reported. The water-balance analysis is used to compute the spatio-temporal water availability with main inputs; the precipitation and actual evapotranspiration rate (AET), both fully derived from public-domain satellite products of Tropical Rainfall Measurement Mission (TRMM) and MODIS, respectively. Both these satellite products were first subjected to calibration to suit corresponding selected local precipitation and AET samples. Multi-temporal data sets acquired 2000-2010 were used in this study. The results of study, indicated strong agreement of monthly water availability with the basin flow rate (r2 = 0.5, p < 0.001). Similar agreements were also noted between the estimated annual average water availability with the in-situ measurement. It is therefore concluded that the method devised in this study provide a new alternative for water availability mapping over large area, hence offers the only timely and cost-effective method apart from providing comprehensive spatio-temporal patterns, crucial in water resource planning to ensure water security.

  9. Impact of intensive dust outbreaks on marine primary production as seen by satellites

    Science.gov (United States)

    Papadimas, Christos; Hatzianastassiou, Nikos; Mihalopoulos, Nikos; Kanakidou, Maria

    2016-04-01

    The impact of intensive dust outbreaks from the African continent on the marine primary production of the Mediterranean sea is here investigated using MODIS satellite observations of atmospheric aerosol optical depth and chlorophyll-a in the seawater. Dust outbreak episodes in the area are detected based on aerosol relevant satellite observations over a 12-year period from 2003 to 2014. For a total of 167 identified episodes, correlations between aerosol optical depth and chlorophyll-a are investigated both on regional and on a pixel by pixel basis as well as for simultaneous or time-lagged satellite observations. The identified co-variations are thoroughly discussed in view of the impact of nutrient atmospheric deposition on the marine biology in the Mediterranean Sea ecosystem. This research has been co-financed by the European Union (European Social Fund - ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: ARISTEIA - PANOPLY (Pollution Alters Natural Aerosol Composition: implications for Ocean Productivity, cLimate and air qualitY) grant.

  10. Crop production and economic loss due to wind erosion in hot arid ecosystem of India

    Science.gov (United States)

    Santra, Priyabrata; Moharana, P. C.; Kumar, Mahesh; Soni, M. L.; Pandey, C. B.; Chaudhari, S. K.; Sikka, A. K.

    2017-10-01

    Wind erosion is a severe land degradation process in hot arid western India and affects the agricultural production system. It affects crop yield directly by damaging the crops through abrasion, burial, dust deposition etc. and indirectly by reducing soil fertility. In this study, an attempt was made to quantify the indirect impact of wind erosion process on crop production loss and associated economic loss in hot arid ecosystem of India. It has been observed that soil loss due to wind erosion varies from minimum 1.3 t ha-1 to maximum 83.3 t ha-1 as per the severity. Yield loss due to wind erosion was found maximum for groundnut (Arachis hypogea) (5-331 kg ha-1 yr-1), whereas minimum for moth bean (Vigna aconitifolia) (1-93 kg ha-1 yr-1). For pearl millet (Pennisetum glaucum), which covers a major portion of arable lands in western Rajasthan, the yield loss was found 3-195 kg ha-1 yr-1. Economic loss was found higher for groundnut and clusterbean (Cyamopsis tetragonoloba) than rest crops, which are about

  11. An atmospheric energy analysis of the impact of satellite lidar winds and TIROS temperatures in global simulations

    Science.gov (United States)

    Keller, Linda M.; Johnson, Donald R.

    1992-01-01

    A study of the effects on forecast accuracy of adding wind-profiler data is conducted. An observing system simulation test is employed that assumes a sufficient concentration of aerosols to provide global wind profiles (a best case scenario). The simulated data for the series of five day forecasts are produced from a twenty day integration utilizing the ECMWF model, which is also employed to produce the verification forecast for the five day period.

  12. Optimisation of Offshore Wind Farm Cable Connection Layout Considering Levelised Production Cost Using Dynamic Minimum Spanning Tree Algorithm

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Chen, Cong

    2016-01-01

    The approach in this paper hads been developed to optimize the cable connection layout of large scale offshore wind farms. The objective is to minimize the Levelised Production Cost (LPC) og an offshore wind farm by optimizing the cable connection configuration. Based on the minimum spanning tree...... and the results are compared with the layout obtained by a traditional MST algorithm. Simulation results show that the proposed method is an effective way for offshore wind farm collection system layout design....

  13. Advanced wind turbine near-term product development. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1996-01-01

    In 1990 the US Department of Energy initiated the Advanced Wind Turbine (AWT) Program to assist the growth of a viable wind energy industry in the US. This program, which has been managed through the National Renewable Energy Laboratory (NREL) in Golden, Colorado, has been divided into three phases: (1) conceptual design studies, (2) near-term product development, and (3) next-generation product development. The goals of the second phase were to bring into production wind turbines which would meet the cost goal of $0.05 kWh at a site with a mean (Rayleigh) windspeed of 5.8 m/s (13 mph) and a vertical wind shear exponent of 0.14. These machines were to allow a US-based industry to compete domestically with other sources of energy and to provide internationally competitive products. Information is given in the report on design values of peak loads and of fatigue spectra and the results of the design process are summarized in a table. Measured response is compared with the results from mathematical modeling using the ADAMS code and is discussed. Detailed information is presented on the estimated costs of maintenance and on spare parts requirements. A failure modes and effects analysis was carried out and resulted in approximately 50 design changes including the identification of ten previously unidentified failure modes. The performance results of both prototypes are examined and adjusted for air density and for correlation between the anemometer site and the turbine location. The anticipated energy production at the reference site specified by NREL is used to calculate the final cost of energy using the formulas indicated in the Statement of Work. The value obtained is $0.0514/kWh in January 1994 dollars. 71 figs., 30 tabs.

  14. Using Satellite Data to Represent Tropical Instability Waves (TIWs-Induced Wind for Ocean Modeling: A Negative Feedback onto TIW Activity in the Pacific

    Directory of Open Access Journals (Sweden)

    Jinzhong Min

    2013-05-01

    Full Text Available Recent satellite data and modeling studies indicate a pronounced role Tropical Instability Waves (TIW-induced wind feedback plays in the tropical Pacific climate system. Previously, remotely sensed data were used to derive a diagnostic model for TIW-induced wind stress perturbations (τTIW, which was embedded into an ocean general circulation model (OGCM to take into account TIW-induced ocean-atmosphere coupling in the tropical Pacific. While the previous paper by Zhang (2013 is concerned with the effect on the mean ocean state, the present paper is devoted to using the embedded system to examine the effects on TIW activity in the ocean, with τTIW being interactively determined from TIW-scale sea surface temperature (SSTTIW fields generated in the OGCM, written as τTIW = αTIW·F(SSTTIW, where αTIW is a scalar parameter introduced to represent the τTIW forcing intensity. Sensitivity experiments with varying αTIW (representing TIW-scale wind feedback strength are performed to illustrate a negative feedback induced by TIW-scale air-sea coupling and its relationship with TIW variability in the ocean. Consistent with previous modeling studies, TIW wind feedback tends to have a damping effect on TIWs in the ocean, with a general inverse relationship between the τTIW intensity and TIWs. It is further shown that TIW-scale coupling does not vary linearly with αTIW: the coupling increases linearly with intensifying τTIW forcing at low values of αTIW (in a weak τTIW forcing regime; it becomes saturated at a certain value of αTIW; it decreases when αTIW goes above a threshold value as the τTIW forcing increases further. This work presents a clear demonstration of using satellite data to effectively represent TIW-scale wind feedback and its multi-scale interactions with large-scale ocean processes in the tropical Pacific.

  15. Value of bias-corrected satellite rainfall products in SWAT simulations and comparison with other models in the Mara basin

    Science.gov (United States)

    Serrat-Capdevila, A.; Abitew, T. A.; Roy, T.; van Griensven, A.; Valdes, J. B.; Bauwens, W.

    2015-12-01

    Hydrometeorological monitoring networks are often limited for basins located in the developing world such as the transboundary Mara Basin. The advent of earth observing systems have brought satellite rainfall and evapotranspiration products, which can be used to force hydrological models in data scarce basins. The objective of this study is to develop improved hydrologic simulations using distributed satellite rainfall products (CMORPH and TMPA) with a bias-correction, and compare the performance with different input data and models. The bias correction approach for the satellite-products (CMORPH and TMPA) involves the use of a distributed reference dataset (CHIRPS) and historical ground gauge records. We have applied the bias-corrected satellite products to force the Soil and Water Assessment Tool (SWAT) model for the Mara Basin. Firstly, we calibrate the SWAT parameters related to ET simulation using ET from remote sensing. Then, the SWAT parameters that control surface processes are calibrated using the available limited flow. From the analysis, we noted that not only the bias-corrected satellite rainfall but also augmenting limited flow data with monthly remote sensing ET improves the model simulation skill and reduces the parameter uncertainty to some extent. We have planned to compare these results from a lumped model forced by the same input satellite rainfall. This will shed light on the potential of satellite rainfall and remote sensing ET along with in situ data for hydrological processes modeling and the inherent uncertainty in a data scarce basin.

  16. An inter-comparison of soil moisture data products from satellite remote sensing and a land surface model

    Science.gov (United States)

    Fang, Li; Hain, Christopher R.; Zhan, Xiwu; Anderson, Martha C.

    2016-06-01

    Significant advances have been achieved in generating soil moisture (SM) products from satellite remote sensing and/or land surface modeling with reasonably good accuracy in recent years. However, the discrepancies among the different SM data products can be considerably large, which hampers their usage in various applications. The bias of one SM product from another is well recognized in the literature. Bias estimation and spatial correction methods have been documented for assimilating satellite SM product into land surface and hydrologic models. Nevertheless, understanding the characteristics of each of these SM data products is required for many applications where the most accurate data products are desirable. This study inter-compares five SM data products from three different sources with each other, and evaluates them against in situ SM measurements over 14-year period from 2000 to 2013. Specifically, three microwave (MW) satellite based data sets provided by ESA's Climate Change Initiative (CCI) (CCI-merged, -active and -passive products), one thermal infrared (TIR) satellite based product (ALEXI), and the Noah land surface model (LSM) simulations. The in-situ SM measurements are collected from the North American Soil Moisture Database (NASMD), which involves more than 600 ground sites from a variety of networks. They are used to evaluate the accuracies of these five SM data products. In general, each of the five SM products is capable of capturing the dry/wet patterns over the study period. However, the absolute SM values among the five products vary significantly. SM simulations from Noah LSM are more stable relative to the satellite-based products. All TIR and MW satellite based products are relatively noisier than the Noah LSM simulations. Even though MW satellite based SM retrievals have been predominantly used in the past years, SM retrievals of the ALEXI model based on TIR satellite observations demonstrate skills equivalent to all the MW satellite

  17. Combining satellite observations to develop a global soil moisture product for near-real-time applications

    Science.gov (United States)

    Enenkel, Markus; Reimer, Christoph; Dorigo, Wouter; Wagner, Wolfgang; Pfeil, Isabella; Parinussa, Robert; De Jeu, Richard

    2016-10-01

    The soil moisture dataset that is generated via the Climate Change Initiative (CCI) of the European Space Agency (ESA) (ESA CCI SM) is a popular research product. It is composed of observations from 10 different satellites and aims to exploit the individual strengths of active (radar) and passive (radiometer) sensors, thereby providing surface soil moisture estimates at a spatial resolution of 0.25°. However, the annual updating cycle limits the use of the ESA CCI SM dataset for operational applications. Therefore, this study proposes an adaptation of the ESA CCI product for daily global updates via satellite-derived near-real-time (NRT) soil moisture observations. In order to extend the ESA CCI SM dataset from 1978 to present we use NRT observations from the Advanced Scatterometer on-board the two MetOp satellites and the Advanced Microwave Scanning Radiometer 2 on-board GCOM-W. Since these NRT observations do not incorporate the latest algorithmic updates, parameter databases and intercalibration efforts, by nature they offer a lower quality than reprocessed offline datasets. In addition to adaptations of the ESA CCI SM processing chain for NRT datasets, the quality of the NRT datasets is a main source of uncertainty. Our findings indicate that, despite issues in arid regions, the new CCI NRT dataset shows a good correlation with ESA CCI SM. The average global correlation coefficient between CCI NRT and ESA CCI SM (Pearson's R) is 0.80. An initial validation with 40 in situ observations in France, Spain, Senegal and Kenya yields an average R of 0.58 and 0.49 for ESA CCI SM and CCI NRT, respectively. In summary, the CCI NRT product is nearly as accurate as the existing ESA CCI SM product and, therefore, of significant value for operational applications such as drought and flood forecasting, agricultural index insurance or weather forecasting.

  18. A Blended Global Snow Product using Visible, Passive Microwave and Scatterometer Satellite Data

    Science.gov (United States)

    Foster, James L.; Hall, Dorothy K.; Eylander, John B.; Riggs, George A.; Nghiem, Son V.; Tedesco, Marco; Kim, Edward; Montesano, Paul M.; Kelly, Richard E. J.; Casey, Kimberly A.; hide

    2009-01-01

    A joint U.S. Air Force/NASA blended, global snow product that utilizes Earth Observation System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS), Advanced Microwave Scanning Radiometer for EOS (AMSR-E) and QuikSCAT (Quick Scatterometer) (QSCAT) data has been developed. Existing snow products derived from these sensors have been blended into a single, global, daily, user-friendly product by employing a newly-developed Air Force Weather Agency (AFWA)/National Aeronautics and Space Administration (NASA) Snow Algorithm (ANSA). This initial blended-snow product uses minimal modeling to expeditiously yield improved snow products, which include snow cover extent, fractional snow cover, snow water equivalent (SWE), onset of snowmelt, and identification of actively melting snow cover. The blended snow products are currently 25-km resolution. These products are validated with data from the lower Great Lakes region of the U.S., from Colorado during the Cold Lands Processes Experiment (CLPX), and from Finland. The AMSR-E product is especially useful in detecting snow through clouds; however, passive microwave data miss snow in those regions where the snow cover is thin, along the margins of the continental snowline, and on the lee side of the Rocky Mountains, for instance. In these regions, the MODIS product can map shallow snow cover under cloud-free conditions. The confidence for mapping snow cover extent is greater with the MODIS product than with the microwave product when cloud-free MODIS observations are available. Therefore, the MODIS product is used as the default for detecting snow cover. The passive microwave product is used as the default only in those areas where MODIS data are not applicable due to the presence of clouds and darkness. The AMSR-E snow product is used in association with the difference between ascending and descending satellite passes or Diurnal Amplitude Variations (DAV) to detect the onset of melt, and a QSCAT product will be used to

  19. Synergistic Effects of Turbine Wakes and Atmospheric Stability on Power Production at an Onshore Wind Farm

    Energy Technology Data Exchange (ETDEWEB)

    Wharton, S; Lundquist, J K; Marjanovic, N

    2012-01-25

    This report examines the complex interactions between atmospheric stability and turbine-induced wakes on downwind turbine wind speed and power production at a West Coast North American multi-MW wind farm. Wakes are generated when the upwind flow field is distorted by the mechanical movement of the wind turbine blades. This has two consequences for downwind turbines: (1) the downwind turbine encounters wind flows with reduced velocity and (2) the downwind turbine encounters increased turbulence across multiple length scales via mechanical turbulence production by the upwind turbine. This increase in turbulence on top of ambient levels may increase aerodynamic fatigue loads on the blades and reduce the lifetime of turbine component parts. Furthermore, ambient atmospheric conditions, including atmospheric stability, i.e., thermal stratification in the lower boundary layer, play an important role in wake dissipation. Higher levels of ambient turbulence (i.e., a convective or unstable boundary layer) lead to higher turbulent mixing in the wake and a faster recovery in the velocity flow field downwind of a turbine. Lower levels of ambient turbulence, as in a stable boundary layer, will lead to more persistent wakes. The wake of a wind turbine can be divided into two regions: the near wake and far wake, as illustrated in Figure 1. The near wake is formed when the turbine structure alters the shape of the flow field and usually persists one rotor diameter (D) downstream. The difference between the air inside and outside of the near wake results in a shear layer. This shear layer thickens as it moves downstream and forms turbulent eddies of multiple length scales. As the wake travels downstream, it expands depending on the level of ambient turbulence and meanders (i.e., travels in non-uniform path). Schepers estimates that the wake is fully expanded at a distance of 2.25 D and the far wake region begins at 2-5 D downstream. The actual distance traveled before the wake

  20. Cross-validation of satellite products over France through their integration into a land surface model

    Science.gov (United States)

    Calvet, Jean-Christophe; Barbu, Alina; Carrer, Dominique; Meurey, Catherine

    2014-05-01

    Long (more than 30 years) time series of satellite-derived products over land are now available. They concern Essential Climate Variables (ECV) such as LAI, FAPAR, surface albedo, and soil moisture. The direct validation of such Climate Data Records (CDR) is not easy, as in situ observations are limited in space and time. Therefore, indirect validation has a key role. It consists in comparing the products with similar preexisting products derived from satellite observations or from land surface model (LSM) simulations. The most advanced indirect validation technique consists in integrating the products into a LSM using a data assimilation scheme. The obtained reanalysis accounts for the synergies of the various upstream products and provides statistics which can be used to monitor the quality of the assimilated observations. Meteo-France develops the ISBA-A-gs generic LSM able to represent the diurnal cycle of the surface fluxes together with the seasonal, interannual and decadal variability of the vegetation biomass. The LSM is embedded in the SURFEX modeling platform together with a simplified extended Kalman filter. These tools form a Land Data Assimilation System (LDAS). The current version of the LDAS assimilates SPOT-VGT LAI and ASCAT surface soil moisture (SSM) products over France (8km x 8km), and a passive monitoring of albedo, FAPAR and Land Surface temperature (LST) is performed (i.e., the simulated values are compared with the satellite products). The LDAS-France system is used in the European Copernicus Global Land Service (http://land.copernicus.eu/global/) to monitor the quality of upstream products. The LDAS generates statistics whose trends can be analyzed in order to detect possible drifts in the quality of the products: (1) for LAI and SSM, metrics derived from the active monitoring (i.e. assimilation) such as innovations (observations vs. model forecast), residuals (observations vs. analysis), and increments (analysis vs. model forecast) ; (2

  1. Micro Fine Sized Palm Oil Fuel Ash Produced Using a Wind Tunnel Production System

    Directory of Open Access Journals (Sweden)

    R. Ahmadi

    2016-01-01

    Full Text Available Micro fine sized palm oil fuel ash (POFA is a new supplementary cementitious material that can increase the strength, durability, and workability of concrete. However, production of this material incurs high cost and is not practical for the construction industry. This paper investigates a simple methodology of producing micro fine sized POFA by means of a laboratory scale wind tunnel system. The raw POFA obtained from an oil palm factory is first calcined to remove carbon residue and then grinded in Los Angeles abrasion machine. The grinded POFA is then blown in the fabricated wind tunnel system for separation into different ranges of particle sizes. The physical, morphological, and chemical properties of the micro fine sized POFA were then investigated using Laser Particle Size Analyser (PSA, nitrogen sorption, and Scanning Electron Microscopy with Energy Dispersive X-Ray (SEM-EDX. A total of 32.1% micro fine sized POFA were collected from each sample blown, with the size range of 1–10 micrometers. The devised laboratory scale of wind tunnel production system is successful in producing micro fine sized POFA and, with modifications, this system is envisaged applicable to be used to commercialize micro fine sized POFA production for the construction industry.

  2. The validation service of the hydrological SAF geostationary and polar satellite precipitation products

    Science.gov (United States)

    Puca, S.; Porcu, F.; Rinollo, A.; Vulpiani, G.; Baguis, P.; Balabanova, S.; Campione, E.; Ertürk, A.; Gabellani, S.; Iwanski, R.; Jurašek, M.; Kaňák, J.; Kerényi, J.; Koshinchanov, G.; Kozinarova, G.; Krahe, P.; Lapeta, B.; Lábó, E.; Milani, L.; Okon, L'.; Öztopal, A.; Pagliara, P.; Pignone, F.; Rachimow, C.; Rebora, N.; Roulin, E.; Sönmez, I.; Toniazzo, A.; Biron, D.; Casella, D.; Cattani, E.; Dietrich, S.; Di Paola, F.; Laviola, S.; Levizzani, V.; Melfi, D.; Mugnai, A.; Panegrossi, G.; Petracca, M.; Sanò, P.; Zauli, F.; Rosci, P.; De Leonibus, L.; Agosta, E.; Gattari, F.

    2014-04-01

    The development phase (DP) of the EUMETSAT Satellite Application Facility for Support to Operational Hydrology and Water Management (H-SAF) led to the design and implementation of several precipitation products, after 5 yr (2005-2010) of activity. Presently, five precipitation estimation algorithms based on data from passive microwave and infrared sensors, on board geostationary and sun-synchronous platforms, function in operational mode at the H-SAF hosting institute to provide near real-time precipitation products at different spatial and temporal resolutions. In order to evaluate the precipitation product accuracy, a validation activity has been established since the beginning of the project. A Precipitation Product Validation Group (PPVG) works in parallel with the development of the estimation algorithms with two aims: to provide the algorithm developers with indications to refine algorithms and products, and to evaluate the error structure to be associated with the operational products. In this paper, the framework of the PPVG is presented: (a) the characteristics of the ground reference data available to H-SAF (i.e. radar and rain gauge networks), (b) the agreed upon validation strategy settled among the eight European countries participating in the PPVG, and (c) the steps of the validation procedures. The quality of the reference data is discussed, and the efforts for its improvement are outlined, with special emphasis on the definition of a ground radar quality map and on the implementation of a suitable rain gauge interpolation algorithm. The work done during the H-SAF development phase has led the PPVG to converge into a common validation procedure among the members, taking advantage of the experience acquired by each one of them in the validation of H-SAF products. The methodology is presented here, indicating the main steps of the validation procedure (ground data quality control, spatial interpolation, up-scaling of radar data vs. satellite grid

  3. Application of MODIS satellite products to the air pollution research in Beijing

    Institute of Scientific and Technical Information of China (English)

    LI; Chengcai; MAO; Jietai; Alexis; K.; H.; Lau; YUAN; Zibin

    2005-01-01

    The direct correlation between NASA MODIS aerosol optical depth (AOD) products and the air pollution index (API) in Beijing was found relatively low based on the long-term comparison analysis. The correlation improved to some extent after taking account of the seasonal variation of scale height and the vertical distribution of aerosols. The correlation coefficient further improved significantly after considering the influencing factor of Relative Humidity (RH). This study concluded that satellite remote-sensing could serve as an efficient tool for monitoring the spatial distribution of particulate pollutants on the ground-level, as long as corrections have been made in the two aforementioned processes. Taking advantage of the MODIS information, we analyzed a pollution episode occurring in October 2004 in Beijing. It indicated that satellite remote-sensing could describe the formation process of the ground-level pollution episode in detail, and showed that regional transport and the topography were crucial factors to air quality in Beijing. The annual averaged distribution in the urban area of Beijing and its surroundings could be also obtained from the high-resolution retrieval results, implicating that high-resolution satellite remote-sensing might be potential in monitoring the source distribution of particulate pollutants.

  4. Net primary productivity of forest stands in New Hampshire estimated from Landsat and MODIS satellite data

    Directory of Open Access Journals (Sweden)

    Genovese Vanessa

    2007-10-01

    Full Text Available Abstract Background A simulation model that relies on satellite observations of vegetation cover from the Landsat 7 sensor and from the Moderate Resolution Imaging Spectroradiometer (MODIS was used to estimate net primary productivity (NPP of forest stands at the Bartlett Experiment Forest (BEF in the White Mountains of New Hampshire. Results Net primary production (NPP predicted from the NASA-CASA model using 30-meter resolution Landsat inputs showed variations related to both vegetation cover type and elevational effects on mean air temperatures. Overall, the highest predicted NPP from the NASA-CASA model was for deciduous forest cover at low to mid-elevation locations over the landscape. Comparison of the model-predicted annual NPP to the plot-estimated values showed a significant correlation of R2 = 0.5. Stepwise addition of 30-meter resolution elevation data values explained no more than 20% of the residual variation in measured NPP patterns at BEF. Both the Landsat 7 and the 250-meter resolution MODIS derived mean annual NPP predictions for the BEF plot locations were within ± 2.5% of the mean of plot estimates for annual NPP. Conclusion Although MODIS imagery cannot capture the spatial details of NPP across the network of closely spaced plot locations as well as Landsat, the MODIS satellite data as inputs to the NASA-CASA model does accurately predict the average annual productivity of a site like the BEF.

  5. Assessment of Satellite-based Precipitation Products (TRMM) in Hydrologic Modeling: Case Studies from Northern Morocco

    Science.gov (United States)

    EL kadiri, R.; Milewski, A.; Durham, M.

    2012-12-01

    Precipitation is the most important forcing parameter in hydrological modeling, yet it is largely unknown in the arid Middle East. We assessed the magnitude, probability of detection, and false alarm rates of various rainfall satellite products (e.g., TRMM, RFE2.0) compared to in situ gauge data (~79 stations) across the Our Er Rbia, Sebou, and Melouya Watersheds in Northern Morocco. Precipitation over the area is relatively high with an average of ~400mm/year according to TRMM (1998-2008). The existing gauges indicate that the average annual precipitation across the Tadla and Coastal Plains region is 260mm/year and 390mm/year across the Atlas Mountains. Following the assessment of satellite products against in situ gauge data, we evaluated the effects (e.g., runoff and recharge amounts) of using satellite driven hydrologic models using SWAT. Specifically, we performed a four-fold exercise: (1) The first stage focused on the analysis of the rainfall products; (2) the second stage involved the construction of a rainfall-runoff model using gauge data; (3) the third stage entailed the calibration of the model against flow gauges and/or dams storage variability, and (4) model simulation using satellite based rainfall products using the calibrated parameters from the initial simulation. Results suggest the TRMM V7 has a much better correlation with the field data over the Oum Er Rbia watershed. The Correlation E (Nash-Suncliffe coefficient) has a positive value of 0.5, while the correlation coefficient of TRMM V6 vs. gauges data is a negative value of -0.25. This first order evaluation of the TRMM V7 shows the new algorithm has partially overcame the underestimation effect in the semi-arid environments. However, more research needs to be done to increase the usability of TRMM V7 in hydrologic models. Low correlations are most likely a result of the following: (1) snow at the high elevations in the Oum Er Rbia watershed, (2) the ocean effect on TRMM measurements along

  6. The Swarm Satellite Constellation Application and Research Facility (SCARF) and Swarm data products

    DEFF Research Database (Denmark)

    Olsen, Nils; Friis-Christensen, Eigil; Floberghagen, R.

    2013-01-01

    Swarm, a three-satellite constellation to study the dynamics of the Earth's magnetic field and its interactions with the Earth system, is expected to be launched in late 2013. The objective of the Swarm mission is to provide the best ever survey of the geomagnetic field and its temporal evolution......, in order to gain new insights into the Earth system by improving our understanding of the Earth's interior and environment. In order to derive advanced models of the geomagnetic field (and other higher-level data products) it is necessary to take explicit advantage of the constellation aspect of Swarm...

  7. Accuracy of 10 m Winds from Satellites and NWP Products Near Land-Sea Boundaries

    Science.gov (United States)

    2008-01-01

    AUTHOR(S) Ahmet Birol Kara, Alan J. Wallcraft, Charlie N. Barron, Harley E. Hurlburt 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER...Principles of Geographical Information Systems, 333 pp., Oxford Univ. Press, New York. Capet, X. J., P. Marchcsiello, and J. C. McWilliams (2004

  8. Validation and Inter-comparison of Satellite Rainfall Products over East Africa's Complex Topography

    Science.gov (United States)

    Dinku, T.; Ceccato, P.; Grover-Kopec, E.; Connor, S. J.; Ropelewski, C. F.

    2006-05-01

    A relatively dense station network of about 140 stations over the highlands of Ethiopia is used to perform an extensive validation and inter-comparison of different semi-operational satellite rainfall products. The validation region is located over 5oN to 13oN, and 35oE to 40oE. It has a very complex topography with alternating valleys and mountain ranges that varies between a point at below sea level and a highest peak of about 4620 meters. The gauge data are obtained from the National Meteorological Services Agency of Ethiopia. The data used in the current research covers the period 1990 to 2004. Though the gage data has already gone through routine quality control by NMSA, it has been subjected to further quality control. The validation and inter-comparison exercise is performed for three groups of products. The first group has low spatial (2.5o) and temporal (monthly) resolutions. These include Global Precipitation Climatology (GPCP) estimates, NOAA-CPC (Climate Prediction Center) Merged Analysis (CMAP), and the Tropical Rainfall Measuring Mission (TRMM) combined "TRMM and Other Sources" product (3B43). The later product has higher spatial resolution (0.25o), but has been remapped to 2.5o in order to compare it with the other products. The second group consists of products with high spatial (0.1o to 1o) and temporal (three-hourly to daily) resolutions. These products include NOAA-CPC African Rainfall Estimation Algorithm (CPC-RFE), GPCP One- Degree-Daily, and TRMM combined "TRMM and Other Satellites" product (3B42). These products are aggregated to a common one-degree and 10-daily total for comparison. The 10-day aggregation period is selected because it is the aggregation used in many operational early warning activities. The third category consists of a relatively new product (available starting from December 2002) from NOAA-CPC named CPC Morphing Technique (CMORPH). CMORPH is available at three-hourly temporal resolution and 0.25o spatial resolution, and it

  9. The effect of blockage on power production for laterally aligned wind turbines

    DEFF Research Database (Denmark)

    Meyer Forsting, Alexander Raul; Troldborg, Niels

    2015-01-01

    This paper studies the change in the individual power coefficients for a laterally aligned row of wind turbines over a single, free turbine in the context of varying inflow directions via numerical simulations. All turbines were rotating in-line with the main flow direction. The problem definition...... to be detrimental in avoiding any domain-inflicted blockage. Increasing the misalignment of the main flow direction with the row of turbines led to significant variations in the power production across turbines. At the largest inflow angle of 45 it varied from -1.1 % to 2 %. As a whole, the power production...

  10. Towards a merged satellite and in situ fluorescence ocean chlorophyll product

    Directory of Open Access Journals (Sweden)

    H. Lavigne

    2011-12-01

    time series, demonstrated that the methods have similar accuracy. Applications of the method were then explored on two different data sets. Using fluorescence profiles at BATS, we show that the integration of "satellite-corrected" fluorescence profiles in Chlorophyll-a climatologies could improve both the statistical relevance of Chlorophyll-a averages and the vertical structure of the Chlorophyll-a field. We also show that our method could be efficiently used to process, within near-real time, profiles obtained by a fluorometer deployed on autonomous platforms, in our case a bio-optical profiling float. The wide application of the proposed method should provide a first step toward the generation of a merged satellite/fluorescence Chlorophyll-a product, as the "satellite-corrected" profiles should then be consistent with satellite observations. Improved climatologies and more consistent satellite and in situ data (comprising those from autonomous platforms should strongly enhance the performance of present biogeochemical models.

  11. Towards a merged satellite and in situ fluorescence ocean chlorophyll product

    Directory of Open Access Journals (Sweden)

    H. Lavigne

    2012-06-01

    accuracy. The method was applied to two different data sets to demonstrate its utility. Using fluorescence profiles at BATS, we show that the integration of "satellite-corrected" fluorescence profiles in chlorophyll a climatologies could improve both the statistical relevance of chlorophyll a averages and the vertical structure of the chlorophyll a field. We also show that our method could be efficiently used to process, within near-real time, profiles obtained by a fluorometer deployed on autonomous platforms, in our case a bio-optical profiling float. The application of the proposed method should provide a first step towards the generation of a merged satellite/fluorescence chlorophyll a product, as the "satellite-corrected" profiles should then be consistent with satellite observations. Improved climatologies with more consistent satellite and in situ data are likely to enhance the performance of present biogeochemical models.

  12. Regulation of the wind power production. Contribution of the electric vehicles and other energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Mateus, Carlos B. [Instituto de Meteorologia, Lisboa (Portugal); Estanqueiro, Ana [INETI/LNEG - National Laboratory for Energy and Geology, Lisbon (Portugal)

    2012-07-01

    The increase in penetration of variable renewable energy sources (RES) introduced additional difficulties regarding the management of the Portuguese Power System. This is mainly due to the high temporal variability and low controllability, characteristics of these kinds of sources. There is a real need to reduce the impact of non-dispatchable RES sources; maximizing their penetration and minimizing curtailment. This is especially true for wind power and run-of-the-river hydro (ROR); as it appears beneficial to combine their variable production with added capacity of energy storage and demand side management; thereby increasing the flexibility of the power system as a whole. This paper aims to assess the excess wind generation (and other non-dispatchable sources); this for periods of production's excess in a 2020 timeframe, and assuming different weather scenarios. The adjustment of wind power generation (WPG) profile to the load profile is also addressed; the result is computed in the form of the value of the energy temporally deferred, using Pumped Hydro Storage (PHS) power plants as well as electric Vehicles (EVs). (orig.)

  13. Pomino: An Improved Satellite NO2 Product for the Ozone Monitoring Instrument

    Science.gov (United States)

    Lin, J.; Martin, R.; Boersma, K. F.; Sneep, M.; Stammes, P.; Spurr, R. J. D.; Wang, P.; Van Roozendael, M.; Clemer, K.; Irie, H.

    2014-12-01

    Tropospheric NO2 columns retrieved from satellite instruments are useful to infer NOx pollution, NOx emissions and atmospheric chemistry. Current satellite products are subject to limitations in assumptions of aerosol optical effects, surface reflectance anisotropy, vertical profiles of NO2, and/or cloud optical properties. Here we develop an improved Peking University Ozone Monitoring Instrument NO2 product (POMINO) for China, complementing the popular DONIMO v2 product. POMINO explicitly accounts for aerosol optical effects, angular dependence of surface reflectance, and dynamically varying atmospheric profiles of air pressure, air temperature and NO2 at a high horizontal resolution (50 km). Prior to the NO2 retrieval, we retrieve cloud top pressure and cloud fraction using consistent assumptions about the states of the atmosphere and surface. For our NO2 and cloud retrievals, we adopt from KNMI (via www.temis.nl) the SCDs of tropospheric NO2 (DOMINO v2) and O2-O2 dimer (OMCLDO2 v1.1.1.3), the TOA reflectance, and some other ancillary information. We develop the AMFv6 code for radiative transfer calculation, based on LIDORT v3.6. Radiative transfer is calculated explicitly for each satellite pixel with no need to use a look-up table. The calculation of AMFv6 is parallelized and is sufficiently fast so that one day of retrieval with global coverage would only take about three hours using 16 CPU cores. POMINO is consistent with MAX-DOAS NO2 data in China, with a R2of 0.96 as compared to the value at 0.72 for DOMINO v2. The improved consistency is related to explicit pixel-by-pixel radiative transfer calculation (instead of using a look-up table), consistent treatments of all parameters in retrieving clouds and NO2, explicit consideration of aerosol optical effects (rather than adjusting 'effective' clouds to implicitly account for aerosols), and consideration of surface reflectance anisotropy. Additional analyses are being conducted on the daily, seasonal and

  14. Weather Satellite Enterprise Information Chain

    Science.gov (United States)

    Jamilkowski, M. L.; Grant, K. D.; Miller, S. W.; Cochran, S.

    2015-12-01

    NOAA & NASA are acquiring the next-generation civilian operational weather satellite: Joint Polar Satellite System (JPSS). Contributing the afternoon orbit & ground system (GS) to replace current NOAA POES Satellites, its sensors will collect meteorological, oceanographic & climatological data. The JPSS Common Ground System (CGS), consisting of C3 and IDP segments, is developed by Raytheon. It now flies the Suomi National Polar-orbiting Partnership (S-NPP) satellite, transferring data between ground facilities, processing them into environmental products for NOAA weather centers, and expanding to support JPSS-1 in 2017. As a multi-mission system, CGS provides combinations of C3, data processing, and product delivery for numerous NASA, NOAA, DoD and international missions.The CGS provides a wide range of support to a number of missions: Command and control and mission management for the S-NPP mission today, expanding this support to the JPSS-1 satellite mission in 2017 Data acquisition for S-NPP, the JAXA's Global Change Observation Mission - Water (GCOM-W1), POES, and the Defense Meteorological Satellite Program (DMSP) and Coriolis/WindSat for the DoD Data routing over a global fiber network for S-NPP, JPSS-1, GCOM-W1, POES, DMSP, Coriolis/WindSat, NASA EOS missions, MetOp for EUMETSAT and the National Science Foundation Environmental data processing and distribution for S-NPP, GCOM-W1 and JPSS-1 The CGS plays a key role in facilitating the movement and value-added enhancement of data all the way from satellite-based sensor data to delivery to the consumers who generate forecasts and produce watches and warnings. This presentation will discuss the information flow from sensors, through data routing and processing, and finally to product delivery. It will highlight how advances in architecture developed through lessons learned from S-NPP and implemented for JPSS-1 will increase data availability and reduce latency for end user applications.

  15. Systematic Evaluation of Satellite-Based Rainfall Products over the Brahmaputra Basin for Hydrological Applications

    Directory of Open Access Journals (Sweden)

    Sagar Ratna Bajracharya

    2015-01-01

    Full Text Available Estimation of the flow generated in the Brahmaputra river basin is important for establishing an effective flood prediction and warning services as well as for water resources assessment and management. But this is a data scarce region with few and unevenly distributed hydrometeorological stations. Five high-resolution satellite rainfall products (CPC RFE2.0, RFE2.0-Modified, CMORPH, GSMaP, and TRMM 3B42 were evaluated at different spatial and temporal resolutions (daily, dekadal, monthly, and seasonal with observed rain gauge data from 2004 to 2006 to determine their ability to fill the data gap and suitability for use in hydrological and water resources management applications. Grid-to-grid (G-G and catchment-to-catchment (C-C comparisons were performed using the verification methods developed by the International Precipitation Working Group (IPWG. Comparing different products, RFE2.0-Modified, TRMM 3B42, and CMORPH performed best; they all detected heavy, moderate, and low rainfall but still significantly underestimated magnitude of rainfall, particularly in orographically influenced areas. Overall, RFE2.0-Modified performed best showing a high correlation coefficient with observed data and low mean absolute error, root mean square error, and multiple bias and is reasonably good at detecting the occurrence of rainfall. TRMM 3B42 showed the second best performance. The study demonstrates that there is a potential use of satellite rainfall in a data scarce region.

  16. NOAA NESDIS global automated satellite-based snow mapping system and products

    Science.gov (United States)

    Romanov, Peter

    2016-05-01

    Accurate, timely and spatially detailed information on the snow cover distribution and on the snow pack properties is needed in various research and practical applications including numerical weather prediction, climate modeling, river runoff estimates and flood forecasts. Owing to the wide area coverage, high spatial resolution and short repeat cycle of observations satellites present one of the key components of the global snow and ice cover monitoring system. The Global Multisensor Automated Snow and Ice Mapping System (GMASI) has been developed at the request of NOAA National Weather Service (NWS) and NOAA National Ice Center (NIC) to facilitate NOAA operational monitoring of snow and ice cover and to provide information on snow and ice for use in NWP models. Since 2006 the system has been routinely generating daily snow and ice cover maps using combined observations in the visible/infrared and in the microwave from operational meteorological satellites. The output product provides continuous (gap free) characterization of the global snow and ice cover distribution at 4 km spatial resolution. The paper presents a basic description of the snow and ice mapping algorithms incorporated in the system as well as of the product generated with GMASI. It explains the approach used to validate the derived snow and ice maps and provides the results of their accuracy assessment.

  17. Global carbon monoxide products from combined AIRS, TES and MLS measurements on A-train satellites

    Directory of Open Access Journals (Sweden)

    J. X. Warner

    2013-06-01

    Full Text Available This study tests a novel methodology to add value to satellite datasets. This methodology, data fusion, is similar to data assimilation, except that the background model-based field is replaced by a satellite dataset, in this case AIRS (Atmospheric Infrared Sounder carbon monoxide (CO measurements. The observational information comes from CO measurements with lower spatial coverage than AIRS, namely, from TES (Tropospheric Emission Spectrometer and MLS (Microwave Limb Sounder. We show that combining these datasets with data fusion uses the higher spectral resolution of TES to extend AIRS CO observational sensitivity to the lower troposphere, a region especially important for air quality studies. We also show that combined CO measurements from AIRS and MLS provide enhanced information in the UTLS (upper troposphere/lower stratosphere region compared to each product individually. The combined AIRS/TES and AIRS/MLS CO products are validated against DACOM (differential absorption mid-IR diode laser spectrometer in situ CO measurements from the INTEX-B (Intercontinental Chemical Transport Experiment: MILAGRO and Pacific phases field campaign and in situ data from HIPPO (HIAPER Pole-to-Pole Observations flights. The data fusion results show improved sensitivities in the lower and upper troposphere (20–30% and above 20%, respectively as compared with AIRS-only retrievals, and improved coverage compared with TES and MLS CO data.

  18. Global Carbon Monoxide Products from Combined AIRS, TES and MLS Measurements on A-Train Satellites

    Science.gov (United States)

    Warner, Juying X.; Yang, R.; Wei, Z.; Carminati, F.; Tangborn, A.; Sun, Z.; Lahoz, W.; Attie, J. L.; El Amraoui, L.; Duncan, B.

    2014-01-01

    This study tests a novel methodology to add value to satellite data sets. This methodology, data fusion, is similar to data assimilation, except that the background modelbased field is replaced by a satellite data set, in this case AIRS (Atmospheric Infrared Sounder) carbon monoxide (CO) measurements. The observational information comes from CO measurements with lower spatial coverage than AIRS, namely, from TES (Tropospheric Emission Spectrometer) and MLS (Microwave Limb Sounder). We show that combining these data sets with data fusion uses the higher spectral resolution of TES to extend AIRS CO observational sensitivity to the lower troposphere, a region especially important for air quality studies. We also show that combined CO measurements from AIRS and MLS provide enhanced information in the UTLS (upper troposphere/lower stratosphere) region compared to each product individually. The combined AIRS-TES and AIRS-MLS CO products are validated against DACOM (differential absorption mid-IR diode laser spectrometer) in situ CO measurements from the INTEX-B (Intercontinental Chemical Transport Experiment: MILAGRO and Pacific phases) field campaign and in situ data from HIPPO (HIAPER Pole-to-Pole Observations) flights. The data fusion results show improved sensitivities in the lower and upper troposphere (20-30% and above 20%, respectively) as compared with AIRS-only version 5 CO retrievals, and improved daily coverage compared with TES and MLS CO data.

  19. Wind Energy

    Energy Technology Data Exchange (ETDEWEB)

    Ganley, Jason; Zhang, Jie; Hodge, Bri-Mathias

    2016-03-15

    Wind energy is a variable and uncertain renewable resource that has long been used to produce mechanical work, and has developed into a large producer of global electricity needs. As renewable sources of energy and feedstocks become more important globally to produce sustainable products, many different processes have started adopting wind power as an energy source. Many times this is through a conversion to hydrogen through electrolysis that allows for a more continuous process input. Other important pathways include methanol and ammonia. As the demand for sustainable products and production pathways increases, and wind power capital costs decrease, the role of wind power in chemical and energy production seems poised to increase significantly.

  20. Estimating Uncertainties in Bio-Optical Products Derived from Satellite Ocean Color Imagery Using an Ensemble Approach

    Science.gov (United States)

    2011-01-01

    We propose a methodology to quantify errors and produce uncertainty maps for satellite-derived ocean color bio -optical products using ensemble...retrievals of bio -optical properties from satellite ocean color imagery are related to a variety of factors, including sensor calibration, atmospheric...correction, and the bio -optical inversion algorithms. Errors propagate, amplify, and intertwine along the processing path, so it is important to

  1. Validating long-term satellite-derived disturbance products: the case of burned areas

    Science.gov (United States)

    Boschetti, L.; Roy, D. P.

    2015-12-01

    The potential research, policy and management applications of satellite products place a high priority on providing statements about their accuracy. A number of NASA, ESA and EU funded global and continental burned area products have been developed using coarse spatial resolution satellite data, and have the potential to become part of a long-term fire Climate Data Record. These products have usually been validated by comparison with reference burned area maps derived by visual interpretation of Landsat or similar spatial resolution data selected on an ad hoc basis. More optimally, a design-based validation method should be adopted that is characterized by the selection of reference data via a probability sampling that can subsequently be used to compute accuracy metrics, taking into account the sampling probability. Design based techniques have been used for annual land cover and land cover change product validation, but have not been widely used for burned area products, or for the validation of global products that are highly variable in time and space (e.g. snow, floods or other non-permanent phenomena). This has been due to the challenge of designing an appropriate sampling strategy, and to the cost of collecting independent reference data. We propose a tri-dimensional sampling grid that allows for probability sampling of Landsat data in time and in space. To sample the globe in the spatial domain with non-overlapping sampling units, the Thiessen Scene Area (TSA) tessellation of the Landsat WRS path/rows is used. The TSA grid is then combined with the 16-day Landsat acquisition calendar to provide tri-dimensonal elements (voxels). This allows the implementation of a sampling design where not only the location but also the time interval of the reference data is explicitly drawn by probability sampling. The proposed sampling design is a stratified random sampling, with two-level stratification of the voxels based on biomes and fire activity (Figure 1). The novel

  2. Use of Real Time Satellite Infrared and Ocean Color to Produce Ocean Products

    Science.gov (United States)

    Roffer, M. A.; Muller-Karger, F. E.; Westhaver, D.; Gawlikowski, G.; Upton, M.; Hall, C.

    2014-12-01

    Real-time data products derived from infrared and ocean color satellites are useful for several types of users around the world. Highly relevant applications include recreational and commercial fisheries, commercial towing vessel and other maritime and navigation operations, and other scientific and applied marine research. Uses of the data include developing sampling strategies for research programs, tracking of water masses and ocean fronts, optimizing ship routes, evaluating water quality conditions (coastal, estuarine, oceanic), and developing fisheries and essential fish habitat indices. Important considerations for users are data access and delivery mechanisms, and data formats. At this time, the data are being generated in formats increasingly available on mobile computing platforms, and are delivered through popular interfaces including social media (Facebook, Linkedin, Twitter and others), Google Earth and other online Geographical Information Systems, or are simply distributed via subscription by email. We review 30 years of applications and describe how we develop customized products and delivery mechanisms working directly with users. We review benefits and issues of access to government databases (NOAA, NASA, ESA), standard data products, and the conversion to tailored products for our users. We discuss advantages of different product formats and of the platforms used to display and to manipulate the data.

  3. Improving User Access to the Integrated Multi-Satellite Retrievals for GPM (IMERG) Products

    Science.gov (United States)

    Huffman, George; Bolvin, David; Nelkin, Eric; Kidd, Christopher

    2016-04-01

    The U.S. Global Precipitation Measurement mission (GPM) team has developed the Integrated Multi-satellitE Retrievals for GPM (IMERG) algorithm to take advantage of the international constellation of precipitation-relevant satellites and the Global Precipitation Climatology Centre surface precipitation gauge analysis. The goal is to provide a long record of homogeneous, high-resolution quasi-global estimates of precipitation. While expert scientific researchers are major users of the IMERG products, it is clear that many other user communities and disciplines also desire access to the data for wide-ranging applications. Lessons learned during the Tropical Rainfall Measuring Mission, the predecessor to GPM, led to some basic design choices that provided the framework for supporting multiple user bases. For example, two near-real-time "runs" are computed, the Early and Late (currently 5 and 15 hours after observation time, respectively), then the Final Run about 3 months later. The datasets contain multiple fields that provide insight into the computation of the complete precipitation data field, as well as diagnostic (currently) estimates of the precipitation's phase. In parallel with this, the archive sites are working to provide the IMERG data in a variety of formats, and with subsetting and simple interactive analysis to make the data more easily available to non-expert users. The various options for accessing the data are summarized under the pmm.nasa.gov data access page. The talk will end by considering the feasibility of major user requests, including polar coverage, a simplified Data Quality Index, and reduced data latency for the Early Run. In brief, the first two are challenging, but under the team's control. The last requires significant action by some of the satellite data providers.

  4. Inventory of future power and heat production technologies. Partial report Wind Power; Inventering av framtidens el- och vaermeproduktionstekniker. Delrapport Vindkraft

    Energy Technology Data Exchange (ETDEWEB)

    Clausen, Niels-Erik; Lawaetz, Henrik; Lemming, Joergen; Morthorst, Poul Erik (Risoe National Laboratory, Roskilde (Denmark))

    2008-12-15

    The development of the wind energy technology has been very successful from the 1970s and up till now. Initially there was a battle between wind turbine concepts, but the commercial winner today is the three-bladed horizontal axis, upwind, electricity producing and grid connected wind turbine with availability on mature markets somewhere around 99%. An important contributor to the growth of the European market for wind energy technology has been EU framework legislation combined with legislation at the national level. The binding target for renewable energy in Sweden is proposed to be 49% of the final energy consumption in 2020 compared to 39.8% in 2005. To stimulate the development of wind energy and to promote a specific national goals Sweden is mainly using an electricity certificate system. The target is to increase the production of electricity from renewable sources by 17 TWh in 2016, relative to corresponding production in 2002. There is not at specific target for the use of wind energy. A future energy system that includes a high proportion of wind energy will be expected to meet the same requirements for security of supply and economic efficiency as the energy systems of today. The variability of wind power create a specific challenges for the future energy systems compared to those of today. The economics of wind power depends mainly of investment cost, operation and maintenance costs, electricity production and turbine lifetime. An average turbine installed in Europe has a total investment cost of 1.230 Euro/kW with a typically variation from approximately 1000 Euro/kW to approximately 1400 Euro/kW. The calculated costs per kWh wind generated power range from approximately 0.07-0.10 Euro/kWh at sites with low average wind speeds to approximately 0.05-0.065 Euro/kWh at good coastal positions, with an average of approximately 0.07 Euro/kWh at a medium wind site. Offshore costs are largely dependent on weather and wave conditions, water depth, and distance

  5. Surface Solar Radiation in North America: Observations, Reanalyses, Satellite and Derived Products

    Science.gov (United States)

    Slater, A. G.

    2015-12-01

    Observations of daily surface solar/shortwave radiation data from over 4000 stations have been gathered, covering much of the lower 48 continental states of the US as well as portions of Alberta and British Columbia, Canada. The quantity of data increases almost linearly from 1998 when only several hundred stations had data. A quality control procedure utilizing threshold values along with computing the clear sky radiation envelope for individual stations was implemented to both screen bad data and rescue informative data. Over two thirds of the observations are seen as acceptable. Fifteen different surface solar radiation products are assessed relative to observations, including reanalyses (20thC, CFSRR, ERAI, JRA-55, MERRA, NARR, NCEP), derived products (CRU_NCEP, DAYMET, GLDAS, GSWP3, MsTMIP, NLDAS) and two satellite products (CERES and GOES). All except the CERES product are daily or finer in temporal resolution. The root mean square error of spatial biases is greater than 18Wm-2 for 13 of the 15 products over the summer season (June, July, August). None of the daily resolution products fulfill all three desirable criteria of low (<5%) annual or seasonal bias, high correlation with observed cloudiness and correct distribution of clear sky radiation. Some products display vestiges of underlying algorithm issues (e.g. from MTCLIM ver4.3) or bias correction methods. A new bias correction method is introduced that preserves clear sky radiation values and better replicates cloudiness statistics. The current quantity of data over the continental US suggests a solar radiation product based on, or enhanced with, observations is feasible.

  6. Solar r-process-constrained actinide production in neutrino-driven winds of supernovae

    Science.gov (United States)

    Goriely, S.; Janka, H.-Th.

    2016-07-01

    Long-lived radioactive nuclei play an important role as nucleo-cosmochronometers and as cosmic tracers of nucleosynthetic source activity. In particular, nuclei in the actinide region like thorium, uranium, and plutonium can testify to the enrichment of an environment by the still enigmatic astrophysical sources that are responsible for the production of neutron-rich nuclei by the rapid neutron-capture process (r-process). Supernovae and merging neutron-star (NS) or NS-black hole binaries are considered as most likely sources of the r-nuclei. But arguments in favour of one or the other or both are indirect and make use of assumptions; they are based on theoretical models with remaining simplifications and shortcomings. An unambiguous observational determination of a production event is still missing. In order to facilitate searches in this direction, e.g. by looking for radioactive tracers in stellar envelopes, the interstellar medium or terrestrial reservoirs, we provide improved theoretical estimates and corresponding uncertainty ranges for the actinide production (232Th, 235, 236, 238U, 237Np, 244Pu, and 247Cm) in neutrino-driven winds of core-collapse supernovae. Since state-of-the-art supernova models do not yield r-process viable conditions - but still lack, for example, the effects of strong magnetic fields - we base our investigation on a simple analytical, Newtonian, adiabatic and steady-state wind model and consider the superposition of a large number of contributing components, whose nucleosynthesis-relevant parameters (mass weight, entropy, expansion time-scale, and neutron excess) are constrained by the assumption that the integrated wind nucleosynthesis closely reproduces the Solar system distribution of r-process elements. We also test the influence of uncertain nuclear physics.

  7. Validation of Reef-Scale Thermal Stress Satellite Products for Coral Bleaching Monitoring

    Directory of Open Access Journals (Sweden)

    Scott F. Heron

    2016-01-01

    Full Text Available Satellite monitoring of thermal stress on coral reefs has become an essential component of reef management practice around the world. A recent development by the U.S. National Oceanic and Atmospheric Administration’s Coral Reef Watch (NOAA CRW program provides daily global monitoring at 5 km resolution—at or near the scale of most coral reefs. In this paper, we introduce two new monitoring products in the CRW Decision Support System for coral reef management: Regional Virtual Stations, a regional synthesis of thermal stress conditions, and Seven-day Sea Surface Temperature (SST Trend, describing recent changes in temperature at each location. We describe how these products provided information in support of management activities prior to, during and after the 2014 thermal stress event in the Commonwealth of the Northern Mariana Islands (CNMI. Using in situ survey data from this event, we undertake the first quantitative comparison between 5 km satellite monitoring products and coral bleaching observations. Analysis of coral community characteristics, historical temperature conditions and thermal stress revealed a strong influence of coral biodiversity in the patterns of observed bleaching. This resulted in a model based on thermal stress and generic richness that explained 97% of the variance in observed bleaching. These findings illustrate the importance of using local benthic characteristics to interpret the level of impact from thermal stress exposure. In an era of continuing climate change, accurate monitoring of thermal stress and prediction of coral bleaching are essential for stakeholders to direct resources to the most effective management actions to conserve coral reefs.

  8. Simulative Winding of Roll Formed Profile in Carcass Production for Flexible Pipes

    DEFF Research Database (Denmark)

    Nielsen, Peter Søe; Ormstrup, Casper Alexander; Hartz, Benjamin Arnold Krekeler;

    2015-01-01

    numerous welds between coils of stainless steel, often duplex grades. The welds are a source of failure, since fracture from time to time occurs here in the winding stage. A simulative test in form of three-point-bending is developed, which shows promising results together with simplified air- and v...... tests using GOM ARAMIS 4M system for strain measurements. The results show strain localization at the weld from onset of yielding caused by the soft, heat affected zone next to the weld seam resulting in a local thinning of the strip similar to what is observed in production....

  9. A calibrated, high-resolution goes satellite solar insolation product for a climatology of Florida evapotranspiration

    Science.gov (United States)

    Paech, S.J.; Mecikalski, J.R.; Sumner, D.M.; Pathak, C.S.; Wu, Q.; Islam, S.; Sangoyomi, T.

    2009-01-01

    Estimates of incoming solar radiation (insolation) from Geostationary Operational Environmental Satellite observations have been produced for the state of Florida over a 10-year period (1995-2004). These insolation estimates were developed into well-calibrated half-hourly and daily integrated solar insolation fields over the state at 2 km resolution, in addition to a 2-week running minimum surface albedo product. Model results of the daily integrated insolation were compared with ground-based pyranometers, and as a result, the entire dataset was calibrated. This calibration was accomplished through a three-step process: (1) comparison with ground-based pyranometer measurements on clear (noncloudy) reference days, (2) correcting for a bias related to cloudiness, and (3) deriving a monthly bias correction factor. Precalibration results indicated good model performance, with a station-averaged model error of 2.2 MJ m-2/day (13%). Calibration reduced errors to 1.7 MJ m -2/day (10%), and also removed temporal-related, seasonal-related, and satellite sensor-related biases. The calibrated insolation dataset will subsequently be used by state of Florida Water Management Districts to produce statewide, 2-km resolution maps of estimated daily reference and potential evapotranspiration for water management-related activities. ?? 2009 American Water Resources Association.

  10. Spatial and Quantitative Comparison of Satellite-Derived Land Cover Products over China

    Institute of Scientific and Technical Information of China (English)

    GAO Hao; JIA Gen-Suo

    2012-01-01

    Because land cover plays an important role in global climate change studies, assessing the agreement among different land cover products is critical. Significant discrepancies have been reported among satellite-derived land cover products, especially at the regional scale. Dif- ferent classification schemes are a key obstacle to the comparison of products and are considered the main fac- tor behind the disagreement among the different products. Using a feature-based overlap metric, we investigated the degree of spatial agreement and quantified the overall and class-specific agreement among the Moderate Resolution Imaging Spectoradiometer (MODIS), Global Land Cover 2000 (GLC2000), and the National Land Cover/Use Data- sets (NLCD) products, and the author assessed the prod- ucts by ground reference data at the regional scale over China. The areas with a low degree of agreement mostly occurred in heterogeneous terrain and transition zones, while the areas with a high degree of agreement occurred in major plains and areas with homogeneous vegetation. The overall agreement of the MODIS and GLC2000 products was 50.8% and 52.9%, and the overall accuracy was 50.3% and 41.9%, respectively. Class-specific agree- ment or accuracy varied significantly. The high-agreement classes are water, grassland, cropland, snow and ice, and bare areas, whereas classes with low agreement are shru- bland and wetland in both MODIS and GLC2000. These characteristics of spatial patterns and quantitative agree- ment could be partly explained by the complex landscapes, mixed vegetation, low separability of spectro-temporal- texture signals, and coarse pixels. The differences of class definition among different the classification schemes also affects the agreement. Each product had its advantages and limitations, but neither the overall accuracy nor the class-specific accuracy could meet the requirements of climate modeling.

  11. Uncertainty analysis of the optical satellite data-derived snow products

    Science.gov (United States)

    Salminen, Miia; Pulliainen, Jouni; Metsämäki, Sari; Luojus, Kari; Böttcher, Kristin; Hannula, Henna-Reetta

    2014-05-01

    The behavior of the global snow cover can be effectively estimated using optical Earth Observation (EO) data, in particular during the end of the melting season. In addition to successful dry and continuous 100% (full) snow cover mapping, optical methods perform well over snowmelt regions with patchy wet snow. Long decadal scale time series of satellite data estimates on global Snow Extent (SE) or Fractional Snow Cover (FSC) and albedo are needed for constructing Climate Data Records (CDR). CDRs have a high relevance in climate research e.g. in climate monitoring including trend analysis and verification of climate models. Currently, the available optical satellite data records for hemispherical snow monitoring reach back for several decades, e.g. AVHRR (since ca 1980), ATSR (since ca 1990), AATSR and MODIS (since ca 2000). Also, the current VIIRS (since 2011) and the future Sentinel-3 both provide very potential data for global snow monitoring. It is fundamental to generate extensive CDRs with quality/estimation error information attached to each snow estimate, as the usefulness of the EO-based snow estimate is highly dependent on the quality of the interpretation. The objective of this work is to establish and develop a methodology to determine a dynamic retrieval error estimate for the optical satellite-retrieved FSC. This is performed by applying an error propagation analysis for the consideration of the statistical error of FSC estimation. The procedure is demonstrated here by using the SCAmod algoritm, which is suited for global snow detection and able to perform well also in forested regions. Apart from determining the statistical (random) error, we outline the procedure for the evaluation of the systematic error (biases) of FSC products, both of which are essential for the generation of snow cover CDR. As we focus here on determining the statistical random error, it is crucial to know the variability of the different factors affecting the satellite

  12. Evaluation of satellite based indices for gross primary production estimates in a sparse savanna in the Sudan

    Directory of Open Access Journals (Sweden)

    M. Sjöström

    2009-01-01

    Full Text Available One of the more frequently applied methods for integrating controls on primary production through satellite data is the Light Use Efficiency (LUE approach. Satellite indices such as the Normalized Difference Vegetation Index (NDVI, Enhanced Vegetation Index (EVI and the Shortwave Infrared Water Stress Index (SIWSI have previously shown promise as predictors of primary production in several different environments. In this study, we evaluate NDVI, EVI and SIWSI derived from the Moderate Resolution Imaging Spectroradiometer (MODIS satellite sensor against in-situ measurements from central Sudan in order to asses their applicability in LUE-based primary production modeling within a water limited environment. Results show a strong correlation between vegetation indices and gross primary production (GPP, demonstrating the significance of vegetation indices for deriving information on primary production with relatively high accuracy at similar areas. Evaluation of SIWSI however, reveal that the fraction of vegetation apparently is to low for the index to provide accurate information on canopy water content, indicating that the use of SIWSI as a predictor of water stress in satellite data-driven primary production modeling in similar semi-arid ecosystems is limited.

  13. Evaluation of GPM-based Multi-satellite IMERG Precipitation Products Over the Lower Colorado River Basin, Texas

    Science.gov (United States)

    Omranian, S. E.; Sharif, H. O.

    2016-12-01

    This study evaluates the Global Precipitation Measurement (GPM) satellite products by analyzing extreme rainfall events over the Lower Colorado River Basin, Texas that resulted in unprecedented flash floods in May 2015. Records of a dense rain gauge network (241 stations) are compared with Integrated Multi-satellite Retrievals for GPM (IMERG) products. The spatial resolution of the GPM satellite product is 0.1º x 0.1º and the temporal resolution is 30 minutes. Reference gauge-based observations are distributed through the basin with total area of over 5,000 square kilometers at 15-minute time intervals. A preliminary assessment of GPM-based IMERG precipitation products shows reasonable correlation, especially when for periods of high amounts of rainfall. the results indicate that GPM satellite products can potentially be employed in hydrologic modeling, especially for large events. Moreover, since the IMERG products have semi-global coverage, it can be extremely useful in hydrological modeling and analysis studies over ungauged or poorly gauged regions.

  14. Satellite remote sensing - An integral tool in acquiring global crop production information

    Science.gov (United States)

    Hall, F. G.

    1982-01-01

    Since NASA's program of research concerning remote sensing was initiated in the 1960s, one of its major objectives has been to advance the state-of-the-art in machine processing of satellite acquired multispectral data. Possibilities have been studied regarding a use of these data to identify type, to monitor condition, and to estimate the ontogenetic stage of cultural vegetation. The present investigation provides a review of the state-of-the-art of the technology used to make remote sensing crop production estimates in foreign regions. Attention is given to Landsat data acquisition, aspects of registration and preprocessing, questions of data transformation, data modeling, proportion estimation, labeling, development stage models, crop condition models, and an outlook regarding future developments.

  15. Maximization of the annual energy production of wind power plants by optimization of layout and yaw-based wake control: Maximization of wind plant AEP by optimization of layout and wake control

    Energy Technology Data Exchange (ETDEWEB)

    Gebraad, Pieter [National Renewable Energy Laboratory, Golden CO USA; Thomas, Jared J. [Brigham Young University, Provo UT USA; Ning, Andrew [Brigham Young University, Provo UT USA; Fleming, Paul [National Renewable Energy Laboratory, Golden CO USA; Dykes, Katherine [National Renewable Energy Laboratory, Golden CO USA

    2016-05-24

    This paper presents a wind plant modeling and optimization tool that enables the maximization of wind plant annual energy production (AEP) using yaw-based wake steering control and layout changes. The tool is an extension of a wake engineering model describing the steady-state effects of yaw on wake velocity profiles and power productions of wind turbines in a wind plant. To make predictions of a wind plant's AEP, necessary extensions of the original wake model include coupling it with a detailed rotor model and a control policy for turbine blade pitch and rotor speed. This enables the prediction of power production with wake effects throughout a range of wind speeds. We use the tool to perform an example optimization study on a wind plant based on the Princess Amalia Wind Park. In this case study, combined optimization of layout and wake steering control increases AEP by 5%. The power gains from wake steering control are highest for region 1.5 inflow wind speeds, and they continue to be present to some extent for the above-rated inflow wind speeds. The results show that layout optimization and wake steering are complementary because significant AEP improvements can be achieved with wake steering in a wind plant layout that is already optimized to reduce wake losses.

  16. Global analysis of ocean surface wind and wind stress using a general circulation model and Seasat scatterometer winds

    Science.gov (United States)

    Kalnay, E.; Atlas, R.

    1986-01-01

    Instantaneous and 15-day time-averaged fields of surface wind, wind stress, curl of the wind stress, and wind divergence are presented. These fields are derived from the Goddard Laboratory for Atmospheres four-dimensional analysis/forecast cycle, for the period September 6-30, 1978, using conventional data, satellite temperature soundings, cloud-track winds, and subjectively dealiased Seasat scatterometer winds.

  17. An Autonomous System to Take Angular Thermal-Infrared Measurements for Validating Satellite Products

    Directory of Open Access Journals (Sweden)

    Raquel Niclòs

    2015-11-01

    Full Text Available An autonomous system for field land surface temperature (LST measurements taken at different observation angles was developed to be deployed easily at any conventional meteorological tower station. The system permits ground-truth data to be acquired on a continuous basis, and angularly scans land and sky hemispheres with a single thermal-infrared (TIR radiometer. This paper describes the autonomous angular system and the methodology to assess ground-truth LST and relative-to-nadir emissivity data from system measurements. Ground-truth LSTs were used to validate satellite-retrieved LST products at two experimental sites (rice crop and shrubland areas. The relative-to-nadir emissivity values were used to analyze the anisotropy of surface emissive properties over thermally-homogeneous covers. The EOS-MODIS MOD11_L2/MYD11_L2 LST product was evaluated and shown to work within expected uncertainties (<2.0 K when tested against the system data. A slight underestimation of around −0.15 K was observed, which became greater for the off-nadir observation angles at the shrubland site. The system took angular measurements for the different seasonal homogeneous covers at the rice crop site. These measurements showed emissivity angular anisotropies, which were in good agreement with previously published data. The dual-view ENVISAT-AATSR data reproduced them, and revealed that the system data collected for thermally-homogeneous surfaces could be used to test future satellite TIR sensors with multi-angular or bi-angular capabilities, like the forthcoming SLSTR on board Copernicus Sentinel-3A.

  18. Applications of MODIS satellite data and products for monitoring air quality in the state of Texas

    Science.gov (United States)

    Hutchison, Keith D.

    The Center for Space Research (CSR), in conjunction with the Monitoring Operations Division (MOD) of the Texas Commission on Environmental Quality (TCEQ), is evaluating the use of remotely sensed satellite data to assist in monitoring and predicting air quality in Texas. The challenges of meeting air quality standards established by the US Environmental Protection Agency (US EPA) are impacted by the transport of pollution into Texas that originates from outside our borders and are cumulative with those generated by local sources. In an attempt to quantify the concentrations of all pollution sources, MOD has installed ground-based monitoring stations in rural regions along the Texas geographic boundaries including the Gulf coast, as well as urban regions that are the predominant sources of domestic pollution. However, analysis of time-lapse GOES satellite imagery at MOD, clearly demonstrates the shortcomings of using only ground-based observations for monitoring air quality across Texas. These shortcomings include the vastness of State borders, that can only be monitored with a large number of ground-based sensors, and gradients in pollution concentration that depend upon the location of the point source, the meteorology governing its transport to Texas, and its diffusion across the region. With the launch of NASA's MODerate resolution Imaging Spectroradiometer (MODIS), the transport of aerosol-borne pollutants can now be monitored over land and ocean surfaces. Thus, CSR and MOD personnel have applied MODIS data to several classes of pollution that routinely impact Texas air quality. Results demonstrate MODIS data and products can detect and track the migration of pollutants. This paper presents one case study in which continental haze from the northeast moved into the region and subsequently required health advisories to be issued for 150 counties in Texas. It is concluded that MODIS provides the basis for developing advanced data products that will, when used in

  19. Utilizing Satellite Precipitation Products to Understand the Link Between Climate Variability and Malaria

    Science.gov (United States)

    Maggioni, V.; Mousam, A.; Delamater, P. L.; Cash, B. A.; Quispe, A.

    2015-12-01

    Malaria is a public health threat to people globally leading to 198 million cases and 584,000 deaths annually. Outbreaks of vector borne diseases such as malaria can be significantly impacted by climate variables such as precipitation. For example, an increase in rainfall has the potential to create pools of water that can serve as breeding locations for mosquitos. Peru is a country that is currently controlling malaria, but has not been able to completely eliminate the disease. Despite the various initiatives in order to control malaria - including regional efforts to improve surveillance, early detection, prompt treatment, and vector management - malaria cases in Peru have risen between 2011 and 2014. The purpose of this study is to test the hypothesis that climate variability plays a fundamental role in malaria occurrence over a 12-year period (2003-2014) in Peru. When analyzing climate variability, it is important to obtain high-quality, high-resolution data for a time series long enough to draw conclusion about how climate variables have been and are changing. Remote sensing is a powerful tool for measuring and monitoring climate variables continuously in time and space. A widely used satellite-based precipitation product, the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA), available globally since 1998, was used to obtain 3-hourly data with a spatial resolution of 0.25° x 0.25°. The precipitation data was linked to weekly (2003-2014) malaria cases collected by health centers and available at a district level all over Peru to investigate the relationship between precipitation and the seasonal and annual variations in malaria incidence. Further studies will incorporate additional climate variables such as temperature, humidity, soil moisture, and surface pressure from remote sensing data products and climate models. Ultimately, this research will help us to understand if climate variability impacts malaria incidence

  20. Comparison of different cloud types from surface and satellite cloud classification products over China

    Science.gov (United States)

    Wang, Minyan; Zeng, Le; Wang, Shengjie; Gu, Junxia; Yang, Runzhi

    2016-04-01

    Different cloud types usually have different cloud dynamic process and micro-physical characteristics, and the relative cloud radiation forcing effects vary much. In recent years, the focus of cloud classification is the algorithm development, as well as the analysis on total cloud amount, high/middle/low cloud amount. While, research on the different cloud types (like cirrus, stratus, and cumulonimbus) is not enough. In this research, we use multi-resources cloud classification products including FY-2, Cloudsat and surface observation to obtain the temporal-spatial distribution characteristics and evolvement of different cloud types in different regions of China, analyze the quantitative difference of multi-source products and the reasons. According to the temporal and spatial scales of cloud, and temporal-spatial representation of cloud classification products based on CloudSat, etc, the scaling is necessary to explore in temporal-spatial matching/validation research. This research have important scientific significances on understanding the regional characteristics of different cloud types in China, improving the remote sensing retrieve algorithms on cloud classification, temporal-spatial matching/validation techniques of satellite data, and cloud vertical structure parameterized methods in numerical models.

  1. Filament Winding of Co-Extruded Polypropylene Tapes for Fully Recyclable All-Polypropylene Composite Products

    Science.gov (United States)

    Cabrera, N. O.; Alcock, B.; Klompen, E. T. J.; Peijs, T.

    2008-01-01

    The creation of high-strength co-extruded polypropylene (PP) tapes allows the production of recyclable “all-polypropylene” (all-PP) composite products, with a large temperature processing window and a high fibre volume fraction. Available technologies for all-PP composites are mostly based on manufacturing processes such as thermoforming of pre-consolidated sheets. The objective of this research is to assess the potential of filament winding as a manufacturing process for all-PP composites made directly from co-extruded tapes or woven fabric. Filament wound pipes or rings were tested either by the split-disk method or a hydrostatic pressure test in order to determine the hoop properties, while an optical strain mapping system was used to measure the deformation of the pipe surfaces.

  2. Wind and Photovoltaic Large-Scale Regional Models for hourly production evaluation

    DEFF Research Database (Denmark)

    Marinelli, Mattia; Maule, Petr; Hahmann, Andrea N.;

    2015-01-01

    This work presents two large-scale regional models used for the evaluation of normalized power output from wind turbines and photovoltaic power plants on a European regional scale. The models give an estimate of renewable production on a regional scale with 1 h resolution, starting from a mesoscale...... mete- orological data input and taking in account the characteristics of different plants technologies and spatial distribution. An evalu- ation of the hourly forecasted energy production on a regional scale would be very valuable for the transmission system operators when making the long-term planning...... of the transmission system, especially regarding the cross-border power flows. The tuning of these regional models is done using historical meteorological data acquired on a per-country basis and using publicly available data of installed capacity....

  3. On the spatial and temporal resolution of land cover products for applied use in wind resource mapping

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Dellwik, Ebba

    The suitability of Copernicus Global Land Service products for wind assessment is investigated using two approaches. In the first approach the CORINE land cover database and the pan-European highresolution products were considered as input to atmospheric flow models. The CORINE data were used...

  4. Wind-driven interannual variability of sea ice algal production over the western Arctic Chukchi Borderland

    Directory of Open Access Journals (Sweden)

    E. Watanabe

    2015-05-01

    Full Text Available Seasonal and interannual variability in sinking flux of biogenic particles was reported by the multi-year bottom-tethered sediment trap measurements in the Northwind Abyssal Plain (Station NAP: 75° N, 162° W, 1975 m water depth of the western Arctic Chukchi Borderland. Whereas the trapped particle flux had an obvious peak with the dominance of sea ice-related diatom valve in August 2011, the observed particle flux was considerably suppressed throughout the summer season in 2012. In the present study, response of ice algal production and biomass to wind-driven changes in physical environments was addressed using a pan-Arctic sea ice–ocean modeling approach. Sea ice ecosystem with ice algae was newly incorporated into the lower-trophic marine ecosystem model, which was previously coupled with a high-resolution (i.e., horizontal grid size of 5 km ocean general circulation model. Seasonal experiments covering two year-long mooring periods indicated that primary productivity of ice algae around the Chukchi Borderland depended on basin-scale wind pattern through various processes. Easterly wind in the southern part of distinct Beaufort High supplied high abundance of nutrient for euphotic zones of the NAP region via both surface Ekman transport of Chukchi shelf water and vertical turbulent mixing with underlying nutricline water as in 2011. In contrast, northwesterly wind flowing in the northern part of extended Siberian High transported oligotrophic water within the Beaufort Gyre circulation toward the NAP region as in 2012. The modeled ice algal biomass during the summer season certainly reflected the differences in nutrient distribution. The sinking flux of Particulate Organic Nitrogen (PON was comparable with the time series obtained from the sediment trap data in summer 2011. On the other hand, lateral advection of shelf-origin ice algal patch during a great cyclone event might have caused a model bias on the PON flux in 2012. The extension

  5. Multiyear monitoring of soil moisture over Iran through satellite and reanalysis soil moisture products

    Science.gov (United States)

    Rahmani, Abdolaziz; Golian, Saeed; Brocca, Luca

    2016-06-01

    Soil moisture (SM) plays a fundamental role for many hydrological applications including water resources, drought analysis, agriculture, and climate variability and extremes. SM is not measured in most parts of Iran and limited measurements do not meet sufficient temporal and spatial resolution. Hence, due to ease of operation, their global coverage and demonstrated accuracy, use of remote sensing SM products is almost the only way for deriving SM information in Iran. In the present research, surface SM (SSM) datasets at six subregions of Iran with different climate conditions were extracted from two satellite-based passive (SMOSL3) and active + passive (ESA CCI SM) microwave observations, and two reanalysis (ERA-Interim and ERA-Interim/Land) products. Time series of averaged monthly mean SSM products and in situ ground precipitation and temperature measurements were derived for each subregion. Results revealed that, generally, all SSM products were in good agreement with each other with correlation coefficients higher than 0.5. The better agreement was found in the Northeast and Southwest region with average correlation values equal to 0.88 and 0.91, respectively. It should be noted that the SSM datasets are characterized by different periods and lengths. Hence, results should be assessed with cautious. Moreover, most SSM products have strong correlations with maximum, minimum and average temperature as well as with total monthly precipitation. Also, trend analysis showed no trend for time series of monthly SSM over all subregions in the two periods 1980-1999 and 2000-2014. The only exceptions were the Southeast subregion for ERA-Interim and Center and Northwest subregions for the ESA CCI SM for which a negative trend was detected for the period 2000-2014. Finally, the Standardized Soil Moisture Index (SSI) calculated from ERA-Interim, ERA-I/Land and ESA CCI SM datasets showed that the Center and Southeast regions suffered from the most severe and longest

  6. Using Social Media and Mobile Devices to Discover and Share Disaster Data Products Derived From Satellites

    Science.gov (United States)

    Mandl, Daniel; Cappelaere, Patrice; Frye, Stuart; Evans, John; Moe, Karen

    2014-01-01

    Data products derived from Earth observing satellites are difficult to find and share without specialized software and often times a highly paid and specialized staff. For our research effort, we endeavored to prototype a distributed architecture that depends on a standardized communication protocol and applications program interface (API) that makes it easy for anyone to discover and access disaster related data. Providers can easily supply the public with their disaster related products by building an adapter for our API. Users can use the API to browse and find products that relate to the disaster at hand, without a centralized catalogue, for example floods, and then are able to share that data via social media. Furthermore, a longerterm goal for this architecture is to enable other users who see the shared disaster product to be able to generate the same product for other areas of interest via simple point and click actions on the API on their mobile device. Furthermore, the user will be able to edit the data with on the ground local observations and return the updated information to the original repository of this information if configured for this function. This architecture leverages SensorWeb functionality [1] presented at previous IGARSS conferences. The architecture is divided into two pieces, the frontend, which is the GeoSocial API, and the backend, which is a standardized disaster node that knows how to talk to other disaster nodes, and also can communicate with the GeoSocial API. The GeoSocial API, along with the disaster node basic functionality enables crowdsourcing and thus can leverage insitu observations by people external to a group to perform tasks such as improving water reference maps, which are maps of existing water before floods. This can lower the cost of generating precision water maps. Keywords-Data Discovery, Disaster Decision Support, Disaster Management, Interoperability, CEOS WGISS Disaster Architecture

  7. Capabilities and uncertainties of aircraft measurements for the validation of satellite precipitation products – a virtual case study

    Directory of Open Access Journals (Sweden)

    Andrea Lammert

    2015-08-01

    Full Text Available Remote sensing sensors on board of research aircraft provide detailed measurements of clouds and precipitation which can be used as reference data to validate satellite products. Such satellite derived precipitation data using passive microwave radiometers with a resolution of typically 50×50km2$50\\times50\\,\\text{km}^2$ stands against high spatial and temporal resolved airborne measurements, but only along a chosen line. This paper focuses on analysis on the uncertainty arising from the different spatial resolution and coverage. Therefore we use a perfect model approach, with a high resolved forecast model yielding perfect virtual aircraft and satellite observations. The mean precipitation and standard deviation per satellite box were estimated with a Gaussian approach. The comparison of the mean values shows a high correlation of 0.92, but a very wide spread. As criterion to define good agreement between satellite mean and reference, we choose a deviation of one standard deviation of the virtual aircraft as threshold. Considering flight tracks in the range of 50 km (one overflight, the perfect agreement of satellite and aircraft observations is only detected in 65 % of the cases. To increase this low reliability the precipitation distributions of the virtual aircraft were fitted by a gamma density function. Using the same quality criterion, the usage of gamma density fit yields an improvement of the Aircraft reliability up to 80 %.

  8. Addressing challenges in combining GOES and LEO satellite products of the CONUS

    Science.gov (United States)

    Petersen, R. A.; Dworak, R.

    2012-12-01

    The challenges of transforming data from the next generation of satellites into information and products for the weather and science purposes presents a major challenge to both the research and applications communities. This will be especially difficult over land, where the process of integrating observations from multiple instruments and platforms in real time is complicated by the influence of the land surface on the observations themselves. In addition, effective merging of the mixture of time-continuous GEO and less frequent but higher spectral resolution LEO observations with other new surface-based observations will be essential and require new product processing strategies. The material shown in this presentation will begin to address some of these issues. It will describe results of efforts to inter-calibrate moisture products derived from existing GEO and LEO data sets over land designed 1) to identify and remove biases from the GOES moisture retrievals, 2) to determine the seasonally varying information content of the GOES relative to NWP model 'first guess' fields, 3) to determine the similarities and differences in error structures between GOES and AIRS retrievals, and 4) to determine the vertical structure of the errors in both systems. For example, comparisons have been made between GOES Total Precipitable Water (TPW) using the Li retrieval system (GOES-Li) and data from Raman Lidar (RL), Microwave Radiometer (MWR) and surface-based GPS-Met systems at the ARM CART site. The test showed for using one year of derived TPW products, the NWP model first guess (GFS) and GOES-Li products are wetter, however the GOES-Li beats the GFS in the warm season, especially in August when the NWP precipitation skill is least. During the warm season GOES-Li is noticeably better than GFS (which was too wet) during daytime. In addition, the GPS-Met data are best during the daytime, while the Ramon Lidar performs best at night. AIRS products were also evaluated for several

  9. Global lightning NOx production estimated by an assimilation of multiple satellite data sets

    Science.gov (United States)

    Miyazaki, K.; Eskes, H. J.; Sudo, K.; Zhang, C.

    2014-04-01

    The global source of lightning-produced NOx (LNOx) is estimated by assimilating observations of NO2, O3, HNO3, and CO measured by multiple satellite measurements into a chemical transport model. Included are observations from the Ozone Monitoring Instrument (OMI), Microwave Limb Sounder (MLS), Tropospheric Emission Spectrometer (TES), and Measurements of Pollution in the Troposphere (MOPITT) instruments. The assimilation of multiple chemical data sets with different vertical sensitivity profiles provides comprehensive constraints on the global LNOx source while improving the representations of the entire chemical system affecting atmospheric NOx, including surface emissions and inflows from the stratosphere. The annual global LNOx source amount and NO production efficiency are estimated at 6.3 Tg N yr-1 and 310 mol NO flash-1, respectively. Sensitivity studies with perturbed satellite data sets, model and data assimilation settings lead to an error estimate of about 1.4 Tg N yr-1 on this global LNOx source. These estimates are significantly different from those estimated from a parameter inversion that optimizes only the LNOx source from NO2 observations alone, which may lead to an overestimate of the source adjustment. The total LNOx source is predominantly corrected by the assimilation of OMI NO2 observations, while TES and MLS observations add important constraints on the vertical source profile. The results indicate that the widely used lightning parameterization based on the C-shape assumption underestimates the source in the upper troposphere and overestimates the peak source height by up to about 1 km over land and the tropical western Pacific. Adjustments are larger over ocean than over land, suggesting that the cloud height dependence is too weak over the ocean in the Price and Rind (1992) approach. The significantly improved agreement between the analyzed ozone fields and independent observations gives confidence in the performance of the LNOx source

  10. Hydrologic evaluation of a Generalized Statistical Uncertainty Model for Satellite Precipitation Products

    Science.gov (United States)

    Sarachi, S.; Hsu, K. L.; Sorooshian, S.

    2014-12-01

    Development of satellite based precipitation retrieval algorithms and using them in hydroclimatic studies have been of great interest to hydrologists. It is important to understand the uncertainty associated with precipitation products and how they further contribute to the variability in stream flow simulation. In this study a mixture model of Generalized Normal Distribution and Gamma distribution (GND-G) is used to model the joint probability distribution of satellite-based (PERSIANN) and stage IV radar rainfall. The study area for constructing the uncertainty model covers a 15°×15°box of 0.25°×0.25° cells over the eastern United States for summer 2004 to 2009. Cells are aggregated in space and time to obtain data with different resolutions for the construction of the model's parameter space. This uncertainty model is evaluated using data from National Weather Service (NWS) Distributed Hydrologic Model Intercomparison Project - Phase 2 (DMIP 2) basin over Illinois River basin south of Siloam, OK. This data covers the time period of 2006 to 2008.The uncertainty range of precipitation is estimated. The impact of precipitation uncertainty to the stream flow estimation is demonstrated by Monte Carlo simulation of precipitation forcing in the Sacramento Soil Moisture Accounting (SAC-SMA) model. The results show that using precipitation along with its uncertainty distribution as forcing to SAC-SMA make it possible to have an estimation of the uncertainty associated with the stream flow simulation ( in this case study %90 confidence interval is used). The mean of this stream flow confidence interval is compared to the reference stream flow for evaluation of the model and the results show that this method helps to better estimate the variability of the stream flow simulation along with its statistics e.g. percent bias and root mean squared error.

  11. On the impact of Multi-GNSS solutions to Satellite Products and Positioning

    Science.gov (United States)

    Abraha, K. E.; Teferle, F. N.; Hunegnaw, A.; Dach, R.

    2016-12-01

    In Global Navigation Satellite System (GNSS) coordinate time series unrecognised errors and un-modelled (periodic) effects may bias non-linear motions induced by geophysical signals. Those spurious signals can be caused either due to un-modelled long periodic signals or propagation of sub-daily signals into the time series. Understanding and mitigating these errors is vital to reduce biases and on revealing subtle geophysical signals. Mostly, the spurious signals are caused by unmodelled errors which recur due to the draconitic years, satellite ground repeats and absorption into resonant GNSS orbits. Accordingly, different features can be observed on GNSS derived products from different single or combined GNSS solutions. To assess the nature of periodic signals on station coordinate time series Precise Point Positioning (PPP) solutions are generated using Bernese GNSS software V5.2. The solutions are considering only Global positioning system (GPS), GLObalnaya NAvigatsionnaya Sputnikovaya Sistema (GLONASS) or combined GPS+GLONASS (GNSS) observations. We assess the periodic signals of station coordinates computed using the combined International GNSS Service (IGS) and four of its Analysis Centers (ACs) products. A faint fortnightly signal in our PPP solution based on Jet Propulsion Laboratory (JPL) products and the existence of 8-day period for those ACs generating a combined GPS+GLONASS solution are the main features in the GPS-only solutions. The existence of the 8-day period in the GPS-only solution indicates that GPS orbits computed from a GNSS solution contain GLONASSspecific signal. The main features in the GLONASS-only solution are highly elevated powers at the 3rd draconitic harmonics ( 120-day period) and 8- day period and its harmonics (4-day, 2.67-day). We show that the GLONASS constellation gaps before December 2011 contribute to the powers of some of the frequencies. However, the well known fortnightly signal in GPS-only solutions is soaked in the

  12. The utility of satellite fire product accuracy information - Perspectives and recommendations from the southern Africa fire network

    NARCIS (Netherlands)

    Roy, D.P.; Trigg, S.N.; Bhima, R.; Brockett, B.H.; Mutanga, O.; Virgilo, S.

    2006-01-01

    This correspondence gives Southern Africa Fire Network (SAFNet) perspectives on the utility of satellite fire product accuracy information, drawing on two main sources: insights gained during SAFNet's six years of working together, and relevant findings from a SAFNet focus group study that explored

  13. Evaluation of the latest satellite-gauge precipitation products and their hydrologic applications over the Huaihe River basin

    Science.gov (United States)

    Sun, Ruochen; Yuan, Huiling; Liu, Xiaoli; Jiang, Xiaoman

    2016-05-01

    Satellite-gauge quantitative precipitation estimate (QPE) products may reduce the errors in near real-time satellite precipitation estimates by combining rain gauge data, which provides great potential to hydrometeorological applications. This study aims to comprehensively evaluate four of the latest satellite-gauge QPEs, including NASA's Tropical Rainfall Measuring Mission (TRMM) 3B42V7 product, NOAA's Climate Prediction Center (CPC) MORPHing technique (CMORPH) bias-corrected product (CMORPH CRT), CMORPH satellite-gauge merged product (CMORPH BLD) and CMORPH satellite-gauge merged product developed at the National Meteorological Information Center (NMIC) of the China Meteorological Administration (CMA) (CMORPH CMA). These four satellite-gauge QPEs are statistically evaluated over the Huaihe River basin during 2003-2012 and applied into the distributed Variable Infiltration Capacity (VIC) model to assess hydrologic utilities. Compared to the China Gauge-based Daily Precipitation Analysis (CGDPA) newly developed at CMA/NMIC, the four satellite-gauge QPEs generally depict the spatial distribution well, with the underestimation in the southern mountains and overestimation in the northern plain of the Huaihe River basin. Specifically, both TRMM and CMORPH CRT adopt simple gauge adjustment algorithms and exhibit relatively poor performance, with evidently deteriorated quality in winter. In contrast, the probability density function-optimal interpolation (PDF-OI) gauge adjustment procedure has been applied in CMORPH BLD and CMORPH CMA, resulting in higher quality and more stable performance. CMORPH CMA further benefits from a merged dense gauge observation network and outperforms the other QPEs with significant improvements in rainfall amount and spatial/temporal distributions. Due to the insufficient gauge observations in the merging process, CMORPH BLD features the similar error characteristics of CMORPH CRT with a positive bias of light precipitation and a negative

  14. Oceanic primary production 2. Estimation at global scale from satellite (coastal zone color scanner) chlorophyll

    Science.gov (United States)

    Antoine, David; André, Jean-Michel; Morel, André

    A fast method has been proposed [Antoine and Morel, this issue] to compute the oceanic primary production from the upper ocean chlorophyll-like pigment concentration, as it can be routinely detected by a spaceborne ocean color sensor. This method is applied here to the monthly global maps of the photosynthetic pigments that were derived from the coastal zone color scanner (CZCS) data archive [Feldman et al., 1989]. The photosynthetically active radiation (PAR) field is computed from the astronomical constant and by using an atmospheric model, thereafter combined with averaged cloud information, derived from the International Satellite Cloud Climatology Project (ISCCP). The aim is to assess the seasonal evolution, as well as the spatial distribution of the photosynthetic carbon fixation within the world ocean and for a ``climatological year,'' to the extent that both the chlorophyll information and the cloud coverage statistics actually are averages obtained over several years. The computed global annual production actually ranges between 36.5 and 45.6 Gt C yr-1 according to the assumption which is made (0.8 or 1) about the ratio of active-to-total pigments (recall that chlorophyll and pheopigments are not radiometrically resolved by CZCS). The relative contributions to the global productivity of the various oceans and zonal belts are examined. By considering the hypotheses needed in such computations, the nature of the data used as inputs, and the results of the sensitivity studies, the global numbers have to be cautiously considered. Improving the reliability of the primary production estimates implies (1) new global data sets allowing a higher temporal resolution and a better coverage, (2) progress in the knowledge of physiological responses of phytoplankton and therefore refinements of the time and space dependent parameterizations of these responses.

  15. Aerus-GEO: newly available satellite-derived aerosol optical depth product over Europe and Africa

    Science.gov (United States)

    Carrer, D.; Roujean, J. L.; Ceamanos, X.; Six, B.; Suman, S.

    2015-12-01

    The major difficulty in detecting the aerosol signal from visible and near-infrared remote sensing observations is to reach the proper separation of the components related to the atmosphere and the surface. A method is proposed to circumvent this issue by exploiting the directional and temporal dimensions of the satellite signal through the use of a semi-empirical kernel-driven model for the surface/atmosphere coupled system. This algorithm was implemented by the ICARE Data Center (http://www.icare.univ-lille1.fr), which operationally disseminates a daily AOD product at 670 nm over the MSG disk since 2014. The proposed method referred to as AERUS-GEO (Aerosol and surface albEdo Retrieval Using a directional Splitting method - application to GEO data) is applied to three spectral bands (0.6 mm, 0.8 mm, and 1.6 mm) of MSG (Meteosat Second Generation) observations, which scan Europe, Africa, and the Eastern part of South America every 15 minutes. The daily AOD estimates at 0.63μm has been extensively validated. In contrast, the Angstrom coefficient is still going through validation and we will show the differences between the MSG derived Angstrom exponent with that of CAMS (Copernicus Atmosphere Monitoring Service) near-real time aerosol product. The impact of aerosol type on the aerosol radiative forcing will be presented as a part of future development plan.

  16. A biophysical process based approach for estimating net primary production using satellite and ground observations

    Science.gov (United States)

    Choudhury, Bhaskar J.

    An approach is presented for calculating interannual variation of net primary production (C) of terrestrial plant communities at regional scale using satellite and ground measurements. C has been calculated as the difference of gross photosynthesis (A g) and respiration (R), recognizing that different biophysical factors exert major control on these two processes. A g has been expressed as the product of radiation use efficiency for gross photosynthesis by an unstressed canopy and intercepted photosynthetically active radiation, which is then adjusted for stresses due to soil water shortage and temperature away from optimum. R has been calculated as the sum of growth and maintenance components (respectively, R g and R m. The R m has been determined from nitrogen content of plant tissue per unit ground area, while R g has been obtained as a fraction of the difference of A g and R m. Model parameters have not been determined by matching the calculated fluxes against observations at any location. Results are presented for cultivated and temperate deciduous forest areas over North America for five consecutive years (1986-1990) and compared with observations.

  17. Overview of software products for the terrain analysis in the tasks of design automation of wind-power stations

    Directory of Open Access Journals (Sweden)

    Volkov Andrey Anatol’evich

    2014-03-01

    Full Text Available The lack of ground and constantly growing price for energy sources are the reason for using alternative energy. The rules of the world community for environmental protection is the motivation for using renewable energy sources. It is necessary to automate the processes of the design technology for the alternative energy structures and their operation, as well as data gathering and analisys on all the existing objects. There is also the need to automise these objects' management. The topic of this article is connected to the analysis of terrain for designing windpower stations. The regional wind maps are valuable tools for the wind farm developer for searching site, but they are not accurate enough to justify the financing of the development. For the majority of prospective wind farms, the developer must undertake a wind resource measurement and use analyzing program. This should provide a robust prediction of the expected energy production over its lifetime. The authors note that a prediction of the energy production of a wind farm is possible using such methods as the wind atlas methodology within WAsP and show the main instruments.

  18. Hydrodynamical numerical simulation of wind production from black hole hot accretion flows at very large radii

    CERN Document Server

    Bu, De-Fu; Gan, Zhao-Ming; Yang, Xiao-hong

    2015-01-01

    In previous works, it has been shown that strong winds exist in hot accretion flows around black holes. Those works focus only on the region close to the black hole thus it is unknown whether or where the wind production stops at large radii. In this paper, we investigate this problem based on hydrodynamical numerical simulations. For this aim, we have taken into account the gravity of both the central black hole and the nuclear star clusters. When calculating the latter, we assume that the velocity dispersion of stars is a constant and the gravitational potential of the nuclear star cluster $\\propto \\sigma^2 \\ln (r)$, where $\\sigma$ is the velocity dispersion of stars and $r$ is the distance from the center of the galaxy. Different from previous works, we focus on the region where the gravitational potential is dominated by the star cluster. We find that, same as the accretion flow at small radii, the mass inflow rate decreases inward and the flow is convectively unstable. However, trajectory analysis has sh...

  19. Evaluation of Six High-Resolution Satellite and Ground-Based Precipitation Products over Malaysia

    Directory of Open Access Journals (Sweden)

    Mou Leong Tan

    2015-01-01

    Full Text Available Satellite precipitation products (SPPs potentially constitute an alternative to sparse rain gauge networks for assessing the spatial distribution of precipitation. However, applications of these products are still limited due to the lack of robust quality assessment. This study compares daily, monthly, seasonal, and annual rainfall amount at 342 rain gauges over Malaysia to estimations using five SPPs (3B42RT, 3B42V7, GPCP-1DD, PERSIANN-CDR, and CMORPH and a ground-based precipitation product (APHRODITE. The performance of the precipitation products was evaluated from 2003 to 2007 using continuous (RMSE, R2, ME, MAE, and RB and categorical (ACC, POD, FAR, CSI, and HSS statistical approaches. Overall, 3B42V7 and APHRODITE performed the best, while the worst performance was shown by GPCP-1DD. 3B42RT, 3B42V7, and PERSIANN-CDR slightly overestimated observed precipitation by 2%, 4.7%, and 2.1%, respectively. By contrast, APHRODITE and CMORPH significantly underestimated precipitations by 19.7% and 13.2%, respectively, whereas GPCP-1DD only slightly underestimated by 2.8%. All six precipitation products performed better in the northeast monsoon than in the southwest monsoon. The better performances occurred in eastern and southern Peninsular Malaysia and in the north of East Malaysia, which receives higher rainfall during the northeast monsoon, whereas poor performances occurred in the western and dryer Peninsular Malaysia. All precipitation products underestimated the no/tiny (<1 mm/day and extreme (≥20 mm/day rainfall events, while they overestimated low (1–20 mm/day rainfall events. 3B42RT and 3B42V7 showed the best ability to detect precipitation amounts with the highest HSS value (0.36. Precipitations during flood events such as those which occurred in late 2006 and early 2007 were estimated the best by 3B42RT and 3B42V7, as shown by an R2 value ranging from 0.49 to 0.88 and 0.52 to 0.86, respectively. These results on SPPs’ uncertainties

  20. Investigation and classification of spume droplets production mechanisms at hurricane winds

    Science.gov (United States)

    Troitskaya, Yuliya; Kandaurov, Alexander; Ermakova, Olga; Kozlov, Dmitry; Sergeev, Daniil; Zilitinkevich, Sergey

    2016-04-01

    : The work was supported by RFBR (Project No. 16-05-00839, 15-35-20953, 14-05-91767), Yu. Troitskaya, D. Sergeev, A. Kandaurov were partially supported by FP7 collaborative project No. 612610, experimental studies of spray generation mechanisms were supported by Russian Science Foundation (Grant No. 15-17-20009), post-processing was supported by Russian Science Foundation (Grant No. 14-17-00667). References: 1. Koga M. Direct production of droplets from breaking wind-waves - its observation by a multi-colored overlapping exposure photographing technique // Tellus. 1981. V.33. Issue 6. P. 552-563 2. Blanchard, D.C., The electrification of the atmosphere by particles from bubbles in the sea, Progr. Oceanogr., 1963. V. 1. P. 71-202. 3. Spiel D.E. On the birth of jet drops from bubbles bursting on water surfaces // J. Geophys. Res. 1995. V.100. P. 4995-5006 4. Villermaux, E. Fragmentation // Annu. Rev. Fluid Mech., 2007. V.39. P.419-446

  1. Development of Deep Learning Based Data Fusion Approach for Accurate Rainfall Estimation Using Ground Radar and Satellite Precipitation Products

    Science.gov (United States)

    Chen, H.; Chandra, C. V.; Tan, H.; Cifelli, R.; Xie, P.

    2016-12-01

    Rainfall estimation based on onboard satellite measurements has been an important topic in satellite meteorology for decades. A number of precipitation products at multiple time and space scales have been developed based upon satellite observations. For example, NOAA Climate Prediction Center has developed a morphing technique (i.e., CMORPH) to produce global precipitation products by combining existing space based rainfall estimates. The CMORPH products are essentially derived based on geostationary satellite IR brightness temperature information and retrievals from passive microwave measurements (Joyce et al. 2004). Although the space-based precipitation products provide an excellent tool for regional and global hydrologic and climate studies as well as improved situational awareness for operational forecasts, its accuracy is limited due to the sampling limitations, particularly for extreme events such as very light and/or heavy rain. On the other hand, ground-based radar is more mature science for quantitative precipitation estimation (QPE), especially after the implementation of dual-polarization technique and further enhanced by urban scale radar networks. Therefore, ground radars are often critical for providing local scale rainfall estimation and a "heads-up" for operational forecasters to issue watches and warnings as well as validation of various space measurements and products. The CASA DFW QPE system, which is based on dual-polarization X-band CASA radars and a local S-band WSR-88DP radar, has demonstrated its excellent performance during several years of operation in a variety of precipitation regimes. The real-time CASA DFW QPE products are used extensively for localized hydrometeorological applications such as urban flash flood forecasting. In this paper, a neural network based data fusion mechanism is introduced to improve the satellite-based CMORPH precipitation product by taking into account the ground radar measurements. A deep learning system is

  2. Hierarchical Satellite-based Approach to Global Monitoring of Crop Condition and Food Production

    Science.gov (United States)

    Zheng, Y.; Wu, B.; Gommes, R.; Zhang, M.; Zhang, N.; Zeng, H.; Zou, W.; Yan, N.

    2014-12-01

    The assessment of global food security goes beyond the mere estimate of crop production: It needs to take into account the spatial and temporal patterns of food availability, as well as physical and economic access. Accurate and timely information is essential to both food producers and consumers. Taking advantage of multiple new remote sensing data sources, especially from Chinese satellites, such as FY-2/3A, HJ-1 CCD, CropWatch has expanded the scope of its international analyses through the development of new indicators and an upgraded operational methodology. The new monitoring approach adopts a hierarchical system covering four spatial levels of detail: global (sixty-five Monitoring and Reporting Units, MRU), seven major production zones (MPZ), thirty-one key countries (including China) and "sub- countries." The thirty-one countries encompass more that 80% of both global exports and production of four major crops (maize, rice, soybean and wheat). The methodology resorts to climatic and remote sensing indicators at different scales, using the integrated information to assess global, regional, and national (as well as sub-national) crop environmental condition, crop condition, drought, production, and agricultural trends. The climatic indicators for rainfall, temperature, photosynthetically active radiation (PAR) as well as potential biomass are first analysed at global scale to describe overall crop growing conditions. At MPZ scale, the key indicators pay more attention to crops and include Vegetation health index (VHI), Vegetation condition index (VCI), Cropped arable land fraction (CALF) as well as Cropping intensity (CI). Together, they characterise agricultural patterns, farming intensity and stress. CropWatch carries out detailed crop condition analyses for thirty one individual countries at the national scale with a comprehensive array of variables and indicators. The Normalized difference vegetation index (NDVI), cropped areas and crop condition are

  3. Bioenergy potential of the United States constrained by satellite observations of existing productivity

    Science.gov (United States)

    Smith, W. Kolby; Cleveland, Cory C.; Reed, Sasha C.; Miller, Norman L.; Running, Steven W.

    2012-01-01

    United States (U.S.) energy policy includes an expectation that bioenergy will be a substantial future energy source. In particular, the Energy Independence and Security Act of 2007 (EISA) aims to increase annual U.S. biofuel (secondary bioenergy) production by more than 3-fold, from 40 to 136 billion liters ethanol, which implies an even larger increase in biomass demand (primary energy), from roughly 2.9 to 7.4 EJ yr–1. However, our understanding of many of the factors used to establish such energy targets is far from complete, introducing significgant uncertainty into the feasibility of current estimates of bioenergy potential. Here, we utilized satellite-derived net primary productivity (NPP) data—measured for every 1 km2 of the 7.2 million km2 of vegetated land in the conterminous U.S.—to estimate primary bioenergy potential (PBP). Our results indicate that PBP of the conterminous U.S. ranges from roughly 5.9 to 22.2 EJ yr–1, depending on land use. The low end of this range represents the potential when harvesting residues only, while the high end would require an annual biomass harvest over an area more than three times current U.S. agricultural extent. While EISA energy targets are theoretically achievable, we show that meeting these targets utilizing current technology would require either an 80% displacement of current crop harvest or the conversion of 60% of rangeland productivity. Accordingly, realistically constrained estimates of bioenergy potential are critical for effective incorporation of bioenergy into the national energy portfolio.

  4. Performance of TMPA satellite precipitation product over the Northern Great Plains

    Science.gov (United States)

    Kharel, G.; Kirilenko, A.; Zhang, X.

    2011-12-01

    Satellite derived precipitation can be used as supplement and/or replacement to ground data in various applications including modeling and weather forecasting based on its accuracy, reliability and validity. We analyzed Tropical Rainfall Measuring Mission Multisatellite Precipitation Analysis (TMPA) 3B42 v.6 Level 3 product (0.25° × 0.25°, 3-hour resolution) against the United States Historical Climatology Network (USHCN) ground data from 98 stations in the Northern Great Plains (NGP) over the period of seven years (2003 to 2009). NGP, comprised of Wyoming, Montana, North Dakota, Minnesota, South Dakota and Nebraska states of the US, is located between the latitudes 41° - 49° N and longitudes 94° - 113.5° E within the TMPA product latitude band (50° NS).The goal of this research was to investigate the performance of TMPA over the NGP region. Results showed that the TMPA daily data has poor rainfall detection ability (POD ~ 0.3), weak correlation with the meteorological data (ρ=0.46) and high root mean square deviation (RMSD = 4.9 mm/day). We also found noticeable seasonal differences in the daily TMPA product performance. It underperformed during cold season (November to March) with weaker correlation (0.25) and worse POD (~ 0.15), as compared to relatively modest correlation (0.47) and POD (~0.30) during warm season (April to October). Our analysis at monthly scale revealed significantly better performance of TMPA with higher correlation (0.82) and lower RMSD (0.72 mm/day). Based on our findings, the TMPA daily data might be a poor replacement to ground data, however, at a monthly scale, TMPA can be used to estimate spatial rainfall distribution in NGP and/or as an input to a stochastic daily weather generator.

  5. Estimation efficiency of usage satellite derived and modelled biophysical products for yield forecasting

    Science.gov (United States)

    Kolotii, Andrii; Kussul, Nataliia; Skakun, Sergii; Shelestov, Andrii; Ostapenko, Vadim; Oliinyk, Tamara

    2015-04-01

    Efficient and timely crop monitoring and yield forecasting are important tasks for ensuring of stability and sustainable economic development [1]. As winter crops pay prominent role in agriculture of Ukraine - the main focus of this study is concentrated on winter wheat. In our previous research [2, 3] it was shown that usage of biophysical parameters of crops such as FAPAR (derived from Geoland-2 portal as for SPOT Vegetation data) is far more efficient for crop yield forecasting to NDVI derived from MODIS data - for available data. In our current work efficiency of usage such biophysical parameters as LAI, FAPAR, FCOVER (derived from SPOT Vegetation and PROBA-V data at resolution of 1 km and simulated within WOFOST model) and NDVI product (derived from MODIS) for winter wheat monitoring and yield forecasting is estimated. As the part of crop monitoring workflow (vegetation anomaly detection, vegetation indexes and products analysis) and yield forecasting SPIRITS tool developed by JRC is used. Statistics extraction is done for landcover maps created in SRI within FP-7 SIGMA project. Efficiency of usage satellite based and modelled with WOFOST model biophysical products is estimated. [1] N. Kussul, S. Skakun, A. Shelestov, O. Kussul, "Sensor Web approach to Flood Monitoring and Risk Assessment", in: IGARSS 2013, 21-26 July 2013, Melbourne, Australia, pp. 815-818. [2] F. Kogan, N. Kussul, T. Adamenko, S. Skakun, O. Kravchenko, O. Kryvobok, A. Shelestov, A. Kolotii, O. Kussul, and A. Lavrenyuk, "Winter wheat yield forecasting in Ukraine based on Earth observation, meteorological data and biophysical models," International Journal of Applied Earth Observation and Geoinformation, vol. 23, pp. 192-203, 2013. [3] Kussul O., Kussul N., Skakun S., Kravchenko O., Shelestov A., Kolotii A, "Assessment of relative efficiency of using MODIS data to winter wheat yield forecasting in Ukraine", in: IGARSS 2013, 21-26 July 2013, Melbourne, Australia, pp. 3235 - 3238.

  6. A DFIG wind turbine ride-through system. Influence on the energy production

    Science.gov (United States)

    Petersson, A.; Lundberg, S.; Thiringer, T.

    2005-07-01

    The influence of a voltage sag ride-through system on the energy production of a doubly-fed induction generator (DFIG) wind turbine is investigated. Using simulations, a candidate ride-through system based on insulated gate bipolar transistor (IGBT) modules with high current rating and with the option of having antiparallel thyristors, which can quickly disconnect the stator of the DFIG from the grid, is developed. It has been found that, by increasing the current rating of the converter IGBTs, the losses of the converter can be reduced. However, if antiparallel thyristors have to be connected between the stator and the grid in order to achieve a fast disconnection of the stator circuit, the overall losses of the total system increase instead. Copyright

  7. Sea Temperature Fiducial Reference Measurements for the Validation and Data Gap Bridging of Satellite SST Data Products

    Science.gov (United States)

    Wimmer, Werenfrid

    2016-08-01

    The Infrared Sea surface temperature Autonomous Radiometer (ISAR) was developed to provide reference data for the validation of satellite Sea Surface Temperature at the Skin interface (SSTskin) temperature data products, particularly the Advanced Along Track Scanning Radiometer (AATSR). Since March 2004 ISAR instruments have been deployed nearly continuously on ferries crossing the English Channel and the Bay of Biscay, between Portsmouth (UK) and Bilbao/Santander (Spain). The resulting twelve years of ISAR data, including an individual uncertainty estimate for each SST record, are calibrated with traceability to national standards (National Institute of Standards and Technology, USA (NIST) and National Physical Laboratory, Teddigton, UK (NPL), Fiducial Reference Measurements for satellite derived surface temperature product validation (FRM4STS)). They provide a unique independent in situ reference dataset against which to validate satellite derived products. We present results of the AATSR validation, and show the use of ISAR fiducial reference measurements as a common traceable validation data source for both AATSR and Sea and Land Surface Temperature Radiometer (SLSTR). ISAR data were also used to review performance of the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) Sea Surface Temperature (SST) analysis before and after the demise of ESA Environmental Satellite (Envisat) when AATSR inputs ceased This demonstrates use of the ISAR reference data set for validating the SST climatologies that will bridge the data gap between AATSR and SLSTR.

  8. Mapping Wind Farm Loads and Power Production - A Case Study on Horns Rev 1

    DEFF Research Database (Denmark)

    Galinos, Christos; Dimitrov, Nikolay Krasimirov; Larsen, Torben J.;

    2016-01-01

    , which has previously been validated based on CFD, Lidar and full scale load measurements. Fully coupled aeroelastic load simulations using turbulent wind conditions are conducted for all wind directions and mean wind speeds between cut-in and cut-out using site specific turbulence level measurements...

  9. Coastal Geostationary Sea Surface Temperature (SST) Products from NOAA GOES and Japanese MTSAT-1R satellites, coastal United States, 2000 - present (NCEI Accession 0108128)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA's Office of Satellite and Data Distribution (OSDPD) generates geostationary sea surface temperature (SST) products. These products are derived from NOAA's...

  10. Evaluating the hydrological consistency of evaporation products using satellite-based gravity and rainfall data

    Science.gov (United States)

    López, Oliver; Houborg, Rasmus; McCabe, Matthew Francis

    2017-01-01

    Advances in space-based observations have provided the capacity to develop regional- to global-scale estimates of evaporation, offering insights into this key component of the hydrological cycle. However, the evaluation of large-scale evaporation retrievals is not a straightforward task. While a number of studies have intercompared a range of these evaporation products by examining the variance amongst them, or by comparison of pixel-scale retrievals against ground-based observations, there is a need to explore more appropriate techniques to comprehensively evaluate remote-sensing-based estimates. One possible approach is to establish the level of product agreement between related hydrological components: for instance, how well do evaporation patterns and response match with precipitation or water storage changes? To assess the suitability of this consistency-based approach for evaluating evaporation products, we focused our investigation on four globally distributed basins in arid and semi-arid environments, comprising the Colorado River basin, Niger River basin, Aral Sea basin, and Lake Eyre basin. In an effort to assess retrieval quality, three satellite-based global evaporation products based on different methodologies and input data, including CSIRO-PML, the MODIS Global Evapotranspiration product (MOD16), and Global Land Evaporation: the Amsterdam Methodology (GLEAM), were evaluated against rainfall data from the Global Precipitation Climatology Project (GPCP) along with Gravity Recovery and Climate Experiment (GRACE) water storage anomalies. To ensure a fair comparison, we evaluated consistency using a degree correlation approach after transforming both evaporation and precipitation data into spherical harmonics. Overall we found no persistent hydrological consistency in these dryland environments. Indeed, the degree correlation showed oscillating values between periods of low and high water storage changes, with a phase difference of about 2-3 months

  11. Solar absorption estimated from surface radiation measurements and collocated satellite products over Europe

    Science.gov (United States)

    Zyta Hakuba, Maria; Folini, Doris; Wild, Martin; Sanchez-Lorenzo, Arturo

    2013-04-01

    Anthropogenic climate change is physically speaking a perturbation of the atmospheric energy budget through the insertion of constituents such as greenhouse gases or aerosols. Changes in the atmospheric energy budget largely affect the global climate and hydrological cycle, but the quantification of the different energy balance components is still afflicted with large uncertainties. The overall aim of the present study is the assessment of the mean state and the spatio-temporal variations in the solar energy disposition, in which we focus on obtaining an accurate partitioning of absorbed solar radiation between the surface and the atmosphere. Surface based measurements of solar radiation (GEBA, BSRN) are combined with collocated satellite-retrieved surface albedo (MODIS, CERES FSW, or CM SAF GAC-SAL) and top-of-atmosphere net incoming solar radiation (CERES EBAF) to quantify the absorbed solar radiation (ASR) at the surface and within the atmosphere over Europe for the period 2001-2005. In a first step, we examine the quality and temporal homogeneity of the monthly time series beyond 2000 provided by GEBA in order to identify a subset of sufficient quality. We find the vast majority of monthly time series to be suitable for our purposes. Using the satellite-derived CM SAF surface solar radiation product at 0.03° spatial resolution, we assess the spatial representativeness of the GEBA and BSRN sites for their collocated 1° grid cells as we intend to combine the point measurements with the coarser resolved CERES EBAF products (1° resolution), and we find spatial sampling errors of on average 3 Wm-2 or 2% (normalized by point values). Based on the combination of 134 GEBA surface solar radiation (SSR) time series with MODIS white-sky albedo and CERES EBAF top-of-atmosphere net radiation (TOAnet), we obtain a European mean partitioning (2001-2005) of absorbed solar radiation (relative to total incoming radiation) of: ASRsurf= 41% and ASRatm= 25%, together equaling

  12. Ionization and NO production in the polar mesosphere during high-speed solar wind streams. Model validation and comparison with NO enhancements observed by Odin-SMR

    Energy Technology Data Exchange (ETDEWEB)

    Kirkwood, S.; Belova, E. [Swedish Institute of Space Physics, Kiruna (Sweden). Polar Atmospheric Research; Osepian, A. [Polar Geophysical Institute, Murmansk (Russian Federation); Urban, J.; Perot, K. [Chalmers Univ. of Technology, Gothenburg (Sweden). Dept. of Radio and Space Science; Sinha, A.K. [Indian Institute of Geomagnetism, Navi Mumbai (India)

    2015-09-01

    Precipitation of high-energy electrons (EEP) into the polar middle atmosphere is a potential source of significant production of odd nitrogen, which may play a role in stratospheric ozone destruction and in perturbing large-scale atmospheric circulation patterns. High-speed streams of solar wind (HSS) are a major source of energization and precipitation of electrons from the Earth's radiation belts, but it remains to be determined whether these electrons make a significant contribution to the odd-nitrogen budget in the middle atmosphere when compared to production by solar protons or by lower-energy (auroral) electrons at higher altitudes, with subsequent downward transport. Satellite observations of EEP are available, but their accuracy is not well established. Studies of the ionization of the atmosphere in response to EEP, in terms of cosmic-noise absorption (CNA), have indicated an unexplained seasonal variation in HSS-related effects and have suggested possible order-of-magnitude underestimates of the EEP fluxes by the satellite observations in some circumstances. Here we use a model of ionization by EEP coupled with an ion chemistry model to show that published average EEP fluxes, during HSS events, from satellite measurements (Meredith et al., 2011), are fully consistent with the published average CNA response (Kavanagh et al., 2012). The seasonal variation of CNA response can be explained by ion chemistry with no need for any seasonal variation in EEP. Average EEP fluxes are used to estimate production rate profiles of nitric oxide between 60 and 100 km heights over Antarctica for a series of unusually well separated HSS events in austral winter 2010. These are compared to observations of changes in nitric oxide during the events, made by the sub-millimetre microwave radiometer on the Odin spacecraft. The observations show strong increases of nitric oxide amounts between 75 and 90 km heights, at all latitudes poleward of 60 S, about 10 days after the

  13. Global Near Real-Time Satellite-based Flood Monitoring and Product Dissemination

    Science.gov (United States)

    Smith, M.; Slayback, D. A.; Policelli, F.; Brakenridge, G. R.; Tokay, M.

    2012-12-01

    Flooding is among the most destructive, frequent, and costly natural disasters faced by modern society, with several major events occurring each year. In the past few years, major floods have devastated parts of China, Thailand, Pakistan, Australia, and the Philippines, among others. The toll of these events, in financial costs, displacement of individuals, and deaths, is substantial and continues to rise as climate change generates more extreme weather events. When these events do occur, the disaster management community requires frequently updated and easily accessible information to better understand the extent of flooding and better coordinate response efforts. With funding from NASA's Applied Sciences program, we have developed, and are now operating, a near real-time global flood mapping system to help provide critical flood extent information within 24-48 hours after flooding events. The system applies a water detection algorithm to MODIS imagery received from the LANCE (Land Atmosphere Near real-time Capability for EOS) system at NASA Goddard. The LANCE system typically processes imagery in less than 3 hours after satellite overpass, and our flood mapping system can output flood products within ½ hour of acquiring the LANCE products. Using imagery from both the Terra (10:30 AM local time overpass) and Aqua (1:30 PM) platforms allows an initial assessment of flooding extent by late afternoon, every day, and more robust assessments after accumulating imagery over a longer period; the MODIS sensors are optical, so cloud cover remains an issue, which is partly overcome by using multiple looks over one or more days. Other issues include the relatively coarse scale of the MODIS imagery (250 meters), the difficulty of detecting flood waters in areas with continuous canopy cover, confusion of shadow (cloud or terrain) with water, and accurately identifying detected water as flood as opposed to normal water extents. We have made progress on some of these issues

  14. Validation of the dynamic wake meander model for loads and power production in the Egmond aan Zee wind farm

    DEFF Research Database (Denmark)

    Larsen, Torben J.; Aagaard Madsen, Helge; Larsen, Gunner Chr.;

    2013-01-01

    This paper investigates wake effects on load and power production by using the dynamic wake meander (DWM) model implemented in the aeroelastic code HAWC2. The instationary wind farm flow characteristics are modeled by treating the wind turbine wakes as passive tracers transported downstream using...... fatigue and min–mean–max loads for blade root flap, tower yaw and tower bottom bending moments, respectively. Since the observed turbine is located deep inside a row of turbines, a new method on how to handle multiple wakes interaction is proposed. The agreement between measurements and simulations...... is excellent regarding power production in both free and wake sector, and a very good agreement is seen for the load comparisons too. This enables the conclusion that wake meandering, caused by large scale ambient turbulence, is indeed an important contribution to wake loading in wind farms. Copyright © 2012...

  15. Integration of radiative transfer into satellite models of ocean primary production

    Science.gov (United States)

    Smyth, T. J.; Tilstone, G. H.; Groom, S. B.

    2005-10-01

    A major goal of ocean color observations from space is the determination of phytoplankton primary productivity (PP) and hence oceanic carbon uptake. Results of a PP model implemented to use satellite-derived fields of chlorophyll, photosynthetically available radiation (PAR) and sea-surface temperature (SST) are presented. The model gave a global estimate of PP of around 57 Gt C yr-1 and gives a low RMS (0.16) when compared with in situ data. However, as the model's in-water light field parameterization only considers attenuation by pure water and chlorophyll, PP is overestimated in case II waters where other optically important constituents such as colored dissolved organic matter (CDOM) and suspended particulate matter (SPM) are also present. This paper develops a novel technique to determine PP by coupling a radiative transfer code, which allows the inclusion of CDOM and SPM, to the original photosynthesis model. For the global calculations, a look-up table has been generated using chlorophyll, CDOM, SST, PAR and day length as inputs. The resultant 364,500 element look-up table has been applied to data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and Moderate-Resolution Imaging Spectroradiometer (MODIS). PP retrievals are improved in case II waters and global estimates are reduced to between 52 and 55 Gt C yr-1.

  16. Solar Occultation Satellite Data and Derived Meteorological Products: Sampling Issues and Comparisons with Aura MLS

    Science.gov (United States)

    Manney, Gloria; Daffer, William H.; Zawodny, Joseph M.; Bernath, Peter F.; Hoppel, Karl W.; Walker, Kaley A.; Knosp, Brian W.; Boone, Chris; Remsberg, Ellis E.; Santee, Michelle L.; Harvey, V. Lynn; Pawson, Steven; Jackson, David R.; Deaver, Lance; Pumphrey, Hugh C.; Lambert, Alyn; Schwartz, Michael J.; Froidevaux, Lucien; McLeod, Sean; Takacs, Lawrence L.; Suarez, Max J.; Trepte, Charles R.; Livesey, Nathaniel; Harwood, Robert S.; Waters, Joe W.

    2007-01-01

    Derived Meteorological Products (DMPs, including potential temperature (theta), potential vorticity, equivalent latitude (EqL), horizontal winds and tropopause locations) have been produced for the locations and times of measurements by several solar occultation (SO) instruments and the Aura Microwave Limb Sounder (MLS). DMPs are calculated from several meteorological analyses for the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer, Stratospheric Aerosol and Gas Experiment II and III, Halogen Occultation Experiment, and Polar Ozone and Aerosol Measurement II and III SO instruments and MLS. Time-series comparisons of MLS version 1.5 and SO data using DMPs show good qualitative agreement in time evolution of O3, N2O, H20, CO, HNO3, HCl and temperature; quantitative agreement is good in most cases. EqL-coordinate comparisons of MLS version 2.2 and SO data show good quantitative agreement throughout the stratosphere for most of these species, with significant biases for a few species in localized regions. Comparisons in EqL coordinates of MLS and SO data, and of SO data with geographically coincident MLS data provide insight into where and how sampling effects are important in interpretation of the sparse SO data, thus assisting in fully utilizing the SO data in scientific studies and comparisons with other sparse datasets. The DMPs are valuable for scientific studies and to facilitate validation of non-coincident measurements.

  17. Power-Production Diagnostic Tools for Low-Density Wind Farms with Applications to Wake Steering

    Science.gov (United States)

    Takle, E. S.; Herzmann, D.; Rajewski, D. A.; Lundquist, J. K.; Rhodes, M. E.

    2016-12-01

    Hansen (2011) provided guidelines for wind farm wake analysis with applications to "high density" wind farms (where average distance between turbines is less than ten times rotor diameter). For "low-density" (average distance greater than fifteen times rotor diameter) wind farms, or sections of wind farms we demonstrate simpler sorting and visualization tools that reveal wake interactions and opportunities for wind farm power prediction and wake steering. SCADA data from a segment of a large mid-continent wind farm, together with surface flux measurements and lidar data are subjected to analysis and visualization of wake interactions. A time-history animated visualization of a plan view of power level of individual turbines provides a quick analysis of wake interaction dynamics. Yaw-based sectoral histograms of enhancement/decline of wind speed and power from wind farm reference levels reveals angular width of wake interactions and identifies the turbine(s) responsible for the power reduction. Concurrent surface flux measurements within the wind farm allowed us to evaluate stability influence on wake loss. A one-season climatology is used to identify high-priority candidates for wake steering based on estimated power recovery. Typical clearing prices on the day-ahead market are used to estimate the added value of wake steering. Current research is exploring options for identifying candidate locations for wind farm "build-in" in existing low-density wind farms.

  18. Reduction of costs of iron production by changing parameters of the mixed blast-furnace wind

    Directory of Open Access Journals (Sweden)

    J. Terpák

    2010-04-01

    Full Text Available The blast-furnace wind from hot-blast stoves is a significant factor of the blast furnace functioning. The technology was analyzed in which the hot wind from hot-blast stoves is not mixed with the cool wind to a constant wind temperature, but is blown directly into the blast furnace. However, it is necessary to compensate for the changes of the theoretical temperature of burning in blast furnace as a consequence of non-stabilized wind temperature, by changing composition of the wind. This can be done by adding different media into the wind with different results from the operational and economical viewpoints. Essentially, the following types of media are used in blast furnaces: steam, oxygen, substitution fuels, nitrogen, and waste gas.

  19. 基于WorldWind平台的卫星云图模拟技术研究%Study of Satellite Cloud Image Simulation Technology Based on WorldWind

    Institute of Scientific and Technical Information of China (English)

    孙恺; 徐晓刚

    2011-01-01

    卫星云图是目前最重要的气象信息来源之一.实现卫星云图的模拟对于灾害预防、评估等工作具有十分重要的意义.首先分析了WorldWind开源平台的系统框架.针对于彩色卫星云图,改进了一种基于图像色彩和灰度值的算法,能够较好地分割提取出云层区域.进而在开源平台WorldWind上采用多层纹理映射的方式实现了卫星云图的模拟.%Satellite cloud image is one of the most important sources of the weather information, and it is of much significance for disaster forecasting and evaluating to do the research of satellite cloud image simulation. The framework of the open-source platform WorldWind was discussed. For the satellite images, the cloud regions were analyzed and segmented by an improved algorithm based on the color value and gray scale. The multilayer texture mapping algorithm is utilized on satellite cloud image simulation, and the procession is integrated to the open-source platform WorldWind.

  20. Wind, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Divergence

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Remote Sensing Inc. distributes science quality wind velocity data from the SeaWinds instrument onboard NASA's QuikSCAT satellite. SeaWinds is a microwave...

  1. Wind, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Zonal

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NASA's Jet Propulsion Laboratory (JPL) distributes science quality wind velocity data from the SeaWinds instrument onboard NASA's QuikSCAT satellite. SeaWinds is a...

  2. Wind, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Zonal

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Remote Sensing Inc. distributes science quality wind velocity data from the SeaWinds instrument onboard NASA's QuikSCAT satellite. SeaWinds is a microwave...

  3. Wind, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Meridional

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NASA's Jet Propulsion Laboratory (JPL) distributes science quality wind velocity data from the SeaWinds instrument onboard NASA's QuikSCAT satellite. SeaWinds is a...

  4. Wind, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Zonal

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Remote Sensing Inc. distributes science quality wind velocity data from the SeaWinds instrument onboard NASA's QuikSCAT satellite. SeaWinds is a microwave...

  5. Wind, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Meridional

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Remote Sensing Inc. distributes science quality wind velocity data from the SeaWinds instrument onboard NASA's QuikSCAT satellite. SeaWinds is a microwave...

  6. Wind, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Modulus

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Remote Sensing Inc. distributes science quality wind velocity data from the SeaWinds instrument onboard NASA's QuikSCAT satellite. SeaWinds is a microwave...

  7. Comparison and evaluation of satellite derived precipitation products for hydrological modeling of the Zambezi River Basin

    Directory of Open Access Journals (Sweden)

    T. Cohen Liechti

    2011-08-01

    Full Text Available In the framework of the African Dams ProjecT (ADAPT, an integrated water resource management study in the Zambezi Basin is currently under development. In view of the sparse gauging network for rainfall monitoring, the observations from spaceborne instrumentation currently produce the only available rainfall data for a large part of the basin.

    Three operational and acknowledged high resolution satellite derived estimates: the Tropical Rainfall Measuring Mission product 3B42 (TRMM 3B42, the Famine Early Warning System product 2.0 (FEWS RFE2.0 and the National Oceanic and Atmospheric Administration/Climate Prediction Centre (NOAA/CPC morphing technique (CMORPH are analyzed in terms of spatial and temporal repartition of the precipitations. They are compared to ground data for the wet seasons of the years 2003 to 2009 on a point to pixel basis at daily, 10-daily and monthly time steps and on a pixel to pixel basis for the wet seasons of the years 2003 to 2007 at monthly time steps.

    The general North-South gradient of precipitation is captured by all the analyzed products. Regarding the spatial heterogeneity, FEWS pixels are much more inter-correlated than TRMM and CMORPH pixels. For a rainfall homogeneity threshold criterion of 0.5 global mean correlation coefficient, the area of each subbasin should not exceed a circle of 2.5° latitude/longitude radius for FEWS and a circle of 0.75° latitude/longitude radius for TRMM and CMORPH considering rectangular mesh.

    In terms of reliability, the correspondence of all estimates with ground data increases with the time step chosen for the analysis. The volume ratio computation indicates that CMORPH is overestimating by nearly 1.5 times the rainfall. The statistics of TRMM and FEWS estimates show quite similar results.

    Due to the its lower inter-correlation and longer data set, the TRMM 3B42 product is chosen as input for the hydraulic-hydrologic model of the basin.

  8. Global, Daily, Near Real-Time Satellite-based Flood Monitoring and Product Dissemination

    Science.gov (United States)

    Slayback, D. A.; Policelli, F. S.; Brakenridge, G. R.; Tokay, M. M.; Smith, M. M.; Kettner, A. J.

    2013-12-01

    Flooding is the most destructive, frequent, and costly natural disaster faced by modern society, and is expected to increase in frequency and damage with climate change and population growth. Some of 2013's major floods have impacted the New York City region, the Midwest, Alberta, Australia, various parts of China, Thailand, Pakistan, and central Europe. The toll of these events, in financial costs, displacement of individuals, and deaths, is substantial and continues to rise as climate change generates more extreme weather events. When these events do occur, the disaster management community requires frequently updated and easily accessible information to better understand the extent of flooding and better coordinate response efforts. With funding from NASA's Applied Sciences program, we developed and are now operating a near real-time global flood mapping system to help provide critical flood extent information within 24-48 hours of events. The system applies a water detection algorithm to MODIS imagery received from the LANCE (Land Atmosphere Near real-time Capability for EOS) system at NASA Goddard within a few hours of satellite overpass. Using imagery from both the Terra (10:30 AM local time overpass) and Aqua (1:30 PM) platforms allows an initial daily assessment of flooding extent by late afternoon, and more robust assessments after accumulating cloud-free imagery over several days. Cloud cover is the primary limitation in detecting surface water from MODIS imagery. Other issues include the relatively coarse scale of the MODIS imagery (250 meters), the difficulty of detecting flood waters in areas with continuous canopy cover, confusion of shadow (cloud or terrain) with water, and accurately identifying detected water as flood as opposed to normal water extents. We have made progress on many of these issues, and are working to develop higher resolution flood detection using alternate sensors, including Landsat and various radar sensors. Although these

  9. Large scale hydrogen production from wind energy in the Magallanes area for consumption in the central zone of Chile

    Energy Technology Data Exchange (ETDEWEB)

    Zolezzi, J.M.; Garay, A.; Reveco, M. [Universidad de Santiago de Chile, Rectoria, Santiago de Chile (Chile)

    2010-12-15

    The energy proposal of this research suggests the use of places with abundant wind resources for the production of H{sub 2} on a large scale to be transported and used in the central zone of Chile with the purpose of diversifying the country's energy matrix in order to decrease its dependence on fossil fuels, increase its autonomy, and cover the future increases in energy demand. This research showed that the load factor of the proposed wind park reaches a value of 54.5%, putting in evidence the excellent wind conditions of the zone. This implies that the cost of the electricity produced by the wind park located in the Chilean Patagonia would have a cost of 0.0213 US$ kWh{sup -1} in the year 2030. The low prices of the electricity obtained from the park, thanks to the economy of scale and the huge wind potential, represent a very attractive scenario for the production of H{sub 2} in the future. The study concludes that by the year 2030 the cost of the H{sub 2} generated in Magallanes and transported to the port of Quinteros would be 18.36 US$ MBTU{sup -1}, while by that time the cost of oil would be about 17.241 US$ MBTU{sup -1}, a situation that places H{sub 2} in a very competitive position as a fuel. (author)

  10. Control, monitoring and data acquisition architecture design for clean production of hydrogen from mini-wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Villarroya, Sebastian; Cotos, Jose M. [Santiago de Compostela Univ. (Spain). Lab. of Systems; Gomez, Guillermo; Plaza, Borja [National Institute for Aerospace Technology (INTA), Torrejon de Ardoz, Madrid (Spain); Fontan, Manuel; Magdaleno, Alexander [OBEKI Innobe, Ibarra, Gipuzkoa (Spain); Vallve, Xavier; Palou, Jaume [Trama TecnoAmbiental, Barcelona (Spain)

    2010-07-01

    One of the pillars that holds up the stability and economic development of our society is the need to ensure a reliable and affordable supply of energy that meets our current energy needs. The high dependence on fossil fuels, our main source of primary energy, has many drawbacks mainly caused by greenhouse gases. It is urgent to address this unsustainable energy future through innovation, adoption of new energy alternatives and better use of existing technologies. In this context, hydrogen associated to renewable energy is probably an important part of that future. This paper presents a real demonstrator of energy generation and storage through the clean production of hydrogen from small wind energy. Thus, this demonstrator will allow the study of the technical and econonmic feasibility of hydrogen production. Wind energy will be stored as hydrogen for a later use. In this way hydrogen represents a form of no-loss energy battery. The use of small wind energy allows a more modular and scattered production even in developing countries. In this way, we avoid the transport of hydrogen and the electricity to produce it, improving system efficiency. Moreover, small wind systems require a lower initial investment in infrastructure which will facilitate the development of a separate market for hydrogen production. (orig.)

  11. The ESA WACMOS-ET project: advancing in the production of evapotranspiration from satellite observations

    Science.gov (United States)

    Jimenez, Carlos

    2014-05-01

    Evapotranspiration (ET) is an essential component of the water and energy cycles. It is highly variable in both space and time, across climates and ecosystems, and difficult to estimate as it does not produce either absorption or emission of electromagnetic signals, which precludes a direct estimation from remote sensing techniques. Therefore global observations related to atmospheric and surface parameters have to be combined with an interpretive model to derive an observational ET product at the global scale. Recent comparisons of satellite-based ET products (e.g., within the LandFlux initiative of the Global Energy and Water Cycle Experiment, GEWEX) have been very useful in providing a first measure of product differences, but not very conclusive in terms of understanding the sources of uncertainty. To further advance in this direction a systematic ET inter-comparison is needed whereby the different ET algorithms are run using (to the greatest possible extent) the same driving data and model protocols. In response to this need, ESA has initiated the WACMOS-ET project, a follow on of the first WACMOS project. While the first WACMOS addressed several components of the water and energy cycle, WACMOS- ET focuses on ET production by different methodologies, and it is aimed at advancing towards the development of ET estimates at global and regional scales. The main objectives are to develop a Reference Input Data Set (RIDS) to derive and validate ET estimates, and to perform a cross-comparison, error characterization, and validation exercise of a group of selected ET algorithms driven by the RIDS. Compared with previous efforts primarily based on combining off-the-shelf input products, the preparation of the RIDS with a large degree of internal consistency is considered essential to (1) evaluate the skill of present algorithms in producing ET, (2) facilitate the attribution of the observed differences to model and driving data limitations, and (3) set up a solid

  12. Spatial analysis of ecosystem production from coordinated in-situ and satellite observations over semi-arid East Asia

    Science.gov (United States)

    Jia, G.; Wang, H.; Zhang, A.

    2016-12-01

    Ecosystem production is a fundamental component of biogeochemical cycles and land-atmosphere interactions at various scales. Semi-arid ecosystems are key contributors to the global carbon cycle and may even dominate the inter-annual variability and decadal trends of the land carbon sink, as demonstrated by several recent studies. Over past years, major achievements have been made to estimate ecosystem productions with satellite data at global and regional scales. However, those estimates were often done with very sparse in-situ data, especially in semi-arid East Asia portion. To better estimate finer resolution primary and ecosystem productions at regional scales, localized field measurements and integration with state-of-art satellite data are necessary. In-situ measurements of green vegetation fractions and CO2 flux between land and atmosphere are critical for understanding regional land-atmosphere interactions and for validating satellite data. Here, we integrated multi-scale satellite data and eddy covariance flux measurements from a pilot experiment of coordinated observation with 24 participant field sites to estimate the gross primary production (GPP) and net ecosystem production (NEP) over semi-arid East Asia from site to regional scale at high temporal and spatial resolution. The coordination started with intensive instruments calibration and field survey based on common protocol. We calculated the footprint sizes and landscape heterogeneity over each site with fine resolution satellite data (Landsat and GF) and evaluated the contribution of vegetation patches to flux signals. The vegetation photosynthesis model was driven with MODIS derived albedo and EVI and coordinated flux measurements. Generally, the GPP in this region were higher in east and lower in west, with distinguished green spots over oasis and montane forests. The estimated annual GPP was 40% greater than MOD17 products. Further, we validated and corrected microwave (AMSR-E and AMSR2) derived

  13. Anticipated detection of favorable periods for wind energy production by means of information theory

    Science.gov (United States)

    Vogel, Eugenio; Saravia, Gonzalo; Kobe, Sigismund; Schumann, Rolf; Schuster, Rolf

    Managing the electric power produced by different sources requires mixing the different response times they present. Thus, for instance, coal burning presents large time lags until operational conditions are reached while hydroelectric generation can react in a matter of some seconds or few minutes to reach the desired productivity. Wind energy production (WEP) can be instantaneously fed to the network to save fuels with low thermal inertia (gas burning for instance), but this source presents sudden variations within few hours. We report here for the first time a method based on information theory to handle WEP. This method has been successful in detecting dynamical changes in magnetic transitions and variations of stock markets. An algorithm called wlzip based on information recognition is used to recognize the information content of a time series. We make use of publically available energy data in Germany to simulate real applications. After a calibration process the system can recognize directly on the WEP data the onset of favorable periods of a desired strength. Optimization can lead to a few hours of anticipation which is enough to control the mixture of WEP with other energy sources, thus saving fuels.

  14. Applications of Satellite Remote Sensing Products to Enhance and Evaluate the AIRPACT Regional Air Quality Modeling System

    Science.gov (United States)

    Herron-Thorpe, F. L.; Mount, G. H.; Emmons, L. K.; Lamb, B. K.; Jaffe, D. A.; Wigder, N. L.; Chung, S. H.; Zhang, R.; Woelfle, M.; Vaughan, J. K.; Leung, F. T.

    2013-12-01

    The WSU AIRPACT air quality modeling system for the Pacific Northwest forecasts hourly levels of aerosols and atmospheric trace gases for use in determining potential health and ecosystem impacts by air quality managers. AIRPACT uses the WRF/SMOKE/CMAQ modeling framework, derives dynamic boundary conditions from MOZART-4 forecast simulations with assimilated MOPITT CO, and uses the BlueSky framework to derive fire emissions. A suite of surface measurements and satellite-based remote sensing data products across the AIRPACT domain are used to evaluate and improve model performance. Specific investigations include anthropogenic emissions, wildfire simulations, and the effects of long-range transport on surface ozone. In this work we synthesize results for multiple comparisons of AIRPACT with satellite products such as IASI ammonia, AIRS carbon monoxide, MODIS AOD, OMI tropospheric ozone and nitrogen dioxide, and MISR plume height. Features and benefits of the newest version of AIRPACT's web-interface are also presented.

  15. Bias correction of satellite precipitation products for flood forecasting application at the Upper Mahanadi River Basin in Eastern India

    Science.gov (United States)

    Beria, H.; Nanda, T., Sr.; Chatterjee, C.

    2015-12-01

    High resolution satellite precipitation products such as Tropical Rainfall Measuring Mission (TRMM), Climate Forecast System Reanalysis (CFSR), European Centre for Medium-Range Weather Forecasts (ECMWF), etc., offer a promising alternative to flood forecasting in data scarce regions. At the current state-of-art, these products cannot be used in the raw form for flood forecasting, even at smaller lead times. In the current study, these precipitation products are bias corrected using statistical techniques, such as additive and multiplicative bias corrections, and wavelet multi-resolution analysis (MRA) with India Meteorological Department (IMD) gridded precipitation product,obtained from gauge-based rainfall estimates. Neural network based rainfall-runoff modeling using these bias corrected products provide encouraging results for flood forecasting upto 48 hours lead time. We will present various statistical and graphical interpretations of catchment response to high rainfall events using both the raw and bias corrected precipitation products at different lead times.

  16. AERONET-OC: Strengths and Weaknesses of a Network for the Validation of Satellite Coastal Radiometric Products

    Science.gov (United States)

    Zibordi, Giuseppe; Holben, Brent; Slutsker, Ilya; Giles, David; D'Alimonte, Davide; Melin, Frederic; Berthon, Jean-Francois; Vandemark, Doug; Feng, Hui; Schuster, Gregory; Fabbri, Bryan E.; Kaitala, Seppo; Seppala, Jukka

    2008-01-01

    The Ocean Color component of the Aerosol Robotic Network (AERONET-OC) has been implemented to support long-term satellite ocean color investigations through cross-site consistent and accurate measurements collected by autonomous radiometer systems deployed on offshore fixed platforms. The ultimate purpose of AERONET-OC is the production of standardized measurements performed at different sites with identical measuring systems and protocols, calibrated using a single reference source and method, and processed with the same code. The AERONET-OC primary data product is the normalized water leaving radiance determined at center-wavelengths of interest for satellite ocean color applications, with an uncertainty lower than 5% in the blue-green spectral regions and higher than 8% in the red. Measurements collected at 6 sites counting the northern Adriatic Sea, the Baltic Proper, the Gulf of Finland, the Persian Gulf, and, the northern and southern margins of the Middle Atlantic Bay, have shown the capability of producing quality assured data over a wide range of bio-optical conditions including Case-2 yellow substance- and sedimentdominated waters. This work briefly introduces network elements like: deployment sites, measurement method, instrument calibration, processing scheme, quality-assurance, uncertainties, data archive and products accessibility. Emphases is given to those elements which underline the network strengths (i.e., mostly standardization of any network element) and its weaknesses (i.e., the use of consolidated, but old-fashioned technology). The work also addresses the application of AERONET-OC data to the validation of primary satellite radiometric products over a variety of complex coastal waters and finally provides elements for the identification of new deployment sites most suitable to support satellite ocean color missions.

  17. Physics-Based GOES Satellite Product for Use in NREL's National Solar Radiation Database: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, M.; Habte, A.; Gotseff, P.; Weekley, A.; Lopez, A.; Molling, C.; Heidinger, A.

    2014-07-01

    The National Renewable Energy Laboratory (NREL), University of Wisconsin, and National Oceanic Atmospheric Administration are collaborating to investigate the integration of the Satellite Algorithm for Shortwave Radiation Budget (SASRAB) products into future versions of NREL's 4-km by 4-km gridded National Solar Radiation Database (NSRDB). This paper describes a method to select an improved clear-sky model that could replace the current SASRAB global horizontal irradiance and direct normal irradiances reported during clear-sky conditions.

  18. Assessing the landscape context and conversion risk of protected areas using satellite data products

    Science.gov (United States)

    Svancara, L.K.; Scott, J.M.; Loveland, T.R.; Pidgorna, A.B.

    2009-01-01

    Since the establishment of the first national park (Yellowstone National Park in 1872) and the first wildlife refuge (Pelican Island in 1903), dramatic changes have occurred in both ecological and cultural landscapes across the U.S. The ability of these protected areas to maintain current levels of biodiversity depend, at least in part, on the integrity of the surrounding landscape. Our objective was to quantify and compare the extent and pattern of natural land cover, risk of conversion, and relationships with demographic and economic variables in counties near National Park Service units and U.S. Fish and Wildlife Service refuges with those counties distant from either type of protected area in the coterminous United States. Our results indicate that landscapes in counties within 10??km of both parks and refuges and those within 10??km of just parks were more natural, more intact, and more protected than those in counties within 10??km of just refuges and counties greater than 10??km from either protected area system. However, they also had greater human population density and change in population, indicating potential conversion risk since the percent of landscape protected averaged 2) in 76% of counties near both parks and refuges, 81% of counties near just parks, 91% of counties near just refuges, and 93% of distant counties. Thirteen percent of counties in the coterminous U.S. had moderate to high amounts of natural land cover (> 60%), low protection ( 20%). Although these areas are not the most critically endangered, they represent the greatest conservation opportunity, need, and urgency. Our approach is based on national level metrics that are simple, general, informative, and can be understood by broad audiences and by policy makers and managers to assess the health of lands surrounding parks and refuges. Regular monitoring of these metrics with satellite data products in counties surrounding protected areas provides a consistent, national level assessment

  19. Evaluation of multiple satellite evaporation products in two dryland regions using GRACE

    KAUST Repository

    Lopez, Oliver

    2015-12-01

    Remote sensing has become a valuable tool for monitoring the water cycle variables in areas that lack the availability of ground-based measurements. Integrating multiple remote sensing-based estimates of evaporation, precipitation, and the terrestrial water storage changes with local measurements of streamflow into a consistent estimate of the regional water budget is a challenge, due to the scale mismatch among the retrieved variables. Evapotranspiration, including soil evaporation, interception losses and canopy transpiration, has received special focus in a number of recent studies that aim to provide global or regional estimates of evaporation at regular time intervals using a variety of remote sensing input. In arid and semi-arid regions, modeling of evaporation is particularly challenging due to the relatively high role of the soil evaporation component in these regions and the variable nature of rainfall events that drive the evaporation process. In this study, we explore the hydrological consistency of remote sensing products in terms of water budget closure and the correlation among spatial patterns of precipitation (P), evaporation (E) and terrestrial water storage, using P-E as a surrogate of water storage changes, with special attention to the evaporation component. The analysis is undertaken within two dryland regions that have presented recent significant changes in climatology (Murray-Darling Basin in Australia) and water storage (the Saq aquifer in northern Saudi Arabia). Water storage changes were derived from the Gravity Recovery and Climate Experiment (GRACE) spherical harmonic (SH) coefficients. Six remote sensing-based evaporation estimates were subtracted from the Global Precipitation Climatology Project (GPCP)-based precipitation estimates and were compared with GRACE-derived water storage changes. Our results suggest that it is not possible to close the water balance by using satellite data alone, even when adopting a spherical harmonic

  20. Assessing variability and long-term trends in burned area by merging multiple satellite fire products

    Directory of Open Access Journals (Sweden)

    L. Giglio

    2009-12-01

    Full Text Available Long term, high quality estimates of burned area are needed for improving both prognostic and diagnostic fire emissions models and for assessing feedbacks between fire and the climate system. We developed global, monthly burned area estimates aggregated to 0.5° spatial resolution for the time period July 1996 through mid-2009 using four satellite data sets. From 2001–2009, our primary data source was 500-m burned area maps produced using Moderate Resolution Imaging Spectroradiometer (MODIS surface reflectance imagery; more than 90% of the global area burned during this time period was mapped in this fashion. During times when the 500-m MODIS data were not available, we used a combination of local regression and regional regression trees to develop relationships between burned area and Terra MODIS active fire data. Cross-calibration with fire observations from the Tropical Rainfall Measuring Mission (TRMM Visible and Infrared Scanner (VIRS and the Along-Track Scanning Radiometer (ATSR allowed the data set to be extended prior to the MODIS era. With our data set we estimated the global annual area burned for the years 1997–2008 varied between 330 and 431 Mha, with the maximum occurring in 1998. We compared our data set to the recent GFED2, L3JRC, GLOBCARBON, and MODIS MCD45A1 global burned area products and found substantial differences in many regions. Lastly, we assessed the interannual variability and long-term trends in global burned area over the past 12 years. This burned area time series serves as the basis for the third version of the Global Fire Emissions Database (GFED3 estimates of trace gas and aerosol emissions.

  1. Assessing variability and long-term trends in burned area by merging multiple satellite fire products

    Directory of Open Access Journals (Sweden)

    L. Giglio

    2010-03-01

    Full Text Available Long term, high quality estimates of burned area are needed for improving both prognostic and diagnostic fire emissions models and for assessing feedbacks between fire and the climate system. We developed global, monthly burned area estimates aggregated to 0.5° spatial resolution for the time period July 1996 through mid-2009 using four satellite data sets. From 2001–2009, our primary data source was 500-m burned area maps produced using Moderate Resolution Imaging Spectroradiometer (MODIS surface reflectance imagery; more than 90% of the global area burned during this time period was mapped in this fashion. During times when the 500-m MODIS data were not available, we used a combination of local regression and regional regression trees developed over periods when burned area and Terra MODIS active fire data were available to indirectly estimate burned area. Cross-calibration with fire observations from the Tropical Rainfall Measuring Mission (TRMM Visible and Infrared Scanner (VIRS and the Along-Track Scanning Radiometer (ATSR allowed the data set to be extended prior to the MODIS era. With our data set we estimated that the global annual area burned for the years 1997–2008 varied between 330 and 431 Mha, with the maximum occurring in 1998. We compared our data set to the recent GFED2, L3JRC, GLOBCARBON, and MODIS MCD45A1 global burned area products and found substantial differences in many regions. Lastly, we assessed the interannual variability and long-term trends in global burned area over the past 13 years. This burned area time series serves as the basis for the third version of the Global Fire Emissions Database (GFED3 estimates of trace gas and aerosol emissions.

  2. Assessing variability and long-term trends in burned area by merging multiple satellite fire products

    Science.gov (United States)

    Giglio, L.; Randerson, J. T.; van der Werf, G. R.; Kasibhatla, P. S.; Collatz, G. J.; Morton, D. C.; Defries, R. S.

    2010-03-01

    Long term, high quality estimates of burned area are needed for improving both prognostic and diagnostic fire emissions models and for assessing feedbacks between fire and the climate system. We developed global, monthly burned area estimates aggregated to 0.5° spatial resolution for the time period July 1996 through mid-2009 using four satellite data sets. From 2001-2009, our primary data source was 500-m burned area maps produced using Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance imagery; more than 90% of the global area burned during this time period was mapped in this fashion. During times when the 500-m MODIS data were not available, we used a combination of local regression and regional regression trees developed over periods when burned area and Terra MODIS active fire data were available to indirectly estimate burned area. Cross-calibration with fire observations from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and the Along-Track Scanning Radiometer (ATSR) allowed the data set to be extended prior to the MODIS era. With our data set we estimated that the global annual area burned for the years 1997-2008 varied between 330 and 431 Mha, with the maximum occurring in 1998. We compared our data set to the recent GFED2, L3JRC, GLOBCARBON, and MODIS MCD45A1 global burned area products and found substantial differences in many regions. Lastly, we assessed the interannual variability and long-term trends in global burned area over the past 13 years. This burned area time series serves as the basis for the third version of the Global Fire Emissions Database (GFED3) estimates of trace gas and aerosol emissions.

  3. Precipitation Analysis at Fine Time Scales Using Multiple Satellites: Real-time and Research Products and Applications

    Science.gov (United States)

    Adler, Robert; Huffman, George; Bolvin, David; Nelkin, Eric; Curtis, Scott; Pierce, Harold

    2004-01-01

    Quasi-global precipitation analyses at fine time scales (3-hr) are described. TRMM observations (radar and passive microwave) are used to calibrate polar-orbit microwave observations from SSM/I (and other satellites instruments, including AMSR and AMSU) and geosynchronous IR observations. The individual data sets are then merged using a priority order based on quality to form the Multi-satellite Precipitation Analysis (MPA). Raingauge information is used to help constrain the satellite-based estimates over land. The TRMM standard research product (Version 6 3B-42 of the TRMM products) will be available for the entire TRMM period (January 1998-present) in 2004. The real-time version of this merged product has been produced over the past two years and is available on the U.S. TRMM web site (trmm.gsfc.nasa.gov) at 0.25" latitude-longitude resolution over the latitude range from 5O"N-5O0S. Validation of daily totals indicates good results, with limitations noted in mid-latitude winter over land and regions of shallow, orographic precipitation. Various applications of these estimates are described, including: 1) detecting potential floods in near real-time; 2) analyzing Indian Ocean precipitation variations related to the initiation of El Nino; 3) determining characteristics of the African monsoon; and 4) analysis of diurnal variations.

  4. Precipitation Analysis at Fine Time Scales using TRMM and Other Satellites: Real-time and Research Products and Applications

    Science.gov (United States)

    Adler, Robert; Huffman, George; Bolvin, David; Nelkin, Eric; Curtis, Scott; Pierce, Harold; Gu, Guo-Jon

    2004-01-01

    Quasi-global precipitation analyses at fine time scales (3-hr) are described. TRMM observations (radar and passive microwave) are used to calibrate polar-orbit microwave observations from SSM/I (and other satellites instruments, including AMSR and AMSU) and geosynchronous IR observations. The individual data sets are then merged using a priority order based on quality to form the TRMM Multi-satellite Precipitation Analysis (MPA). Raingauge information is used to help constrain the satellite-based estimates over land. The TRMM standard research product (Version 6 3B-42 of the TRMM products) will be available for the entire TRMM period (January 1998-present) by the end of 2004. The real-time version of this merged product has been produced over the past two years and is available on the U.S. TRMM web site (trmm.gsfc.nasa.gov) at 0.25" latitude-longitude resolution over the latitude range from 5O0N-50"S. Validation of daily totals indicates good results, with limitations noted in mid-latitude winter over land and regions of shallow, orographic precipitation. Various applications of these estimates are described, includmg: 1) detecting potential floods in near real-time; 2) analyzing Indian Ocean precipitation variations related to the initiation of El Nino; 3) determining characteristics of the African monsoon; and 4) analysis of diurnal variations.

  5. Baseload power production from wind turbine arrays coupled to compressed air energy storage

    Science.gov (United States)

    Succar, Samir

    An analysis is presented of compressed air energy storage (CAES) and its potential for mitigating the intermittency of wind power, facilitating access to remote wind resources and transforming wind into baseload power. Although CAES has traditionally served other grid support applications, it is also well suited for wind balancing applications due its ability to provide long duration storage, its fast ramp rates and its high part load efficiencies. In addition, geologies potentially suitable for CAES appear to be abundant in regions with high-quality wind resources. This is especially true of porous rock formations, which have the potential to be the least costly air storage option for CAES. The characteristics of formations suitable for CAES storage and the challenges associated with using air as a storage fluid are discussed. An optimization framework is developed for analyzing the cost of baseload plants comprised of wind turbine arrays backed by natural gas-fired generating capacity and/or CAES. The optimization model analyzes changes to key aspects of the system configuration such as the wind turbine rating, the relative capacities of the system components, the size of the CAES storage reservoir and the wind turbine spacing. The response of the optimal system configuration to changes in natural gas price, greenhouse gas (GHG) emissions price, capital cost, and wind resource is also considered. Wind turbine rating is given focused attention because of its substantial impact on system configuration and output behavior. The generation cost of baseload wind is compared to that of other baseload options. To highlight the carbon-mitigation potential of baseload wind, the competition with coal power (with and without CO2 capture and storage, CCS) is given prominent attention. The ability of alternative options to compete under dispatch competition is explored thereby clarifying the extent to which baseload wind can defend high capacity factors in the market. This

  6. How to make the production of methanol/DME "GREENER"-Integration of wind power with modern coal chemical industry

    Institute of Scientific and Technical Information of China (English)

    Weidou NI; Jian GAO; Zhen CHEN; Zheng LI

    2009-01-01

    The urgency and necessity of alternative fuels give an impetus to the development of modern coal chemical industry. Coal-based methanol/DME is the key element of this industry. Wind power, whose installed capacity increased at a rate of more than 100% in recent years, has the most developed technologies in renewable energy. However, there still exist many unsolved problems in wind power for on-grid utilization. A new integrated system which combines coal-based methanol/DME production with wind power is proposed in this paper. In this system, wind power is used to electrolyze water to produce H2 and O2. The O2 is fed to the gasifier as gasification agent. The H2 is mixed with the CO-rich gas to adjust the H2/CO to an appropriate ratio for methanol synthesis. In comparison with conventional coal-based methanol/DME system, the proposed system omits the expensive and energy-consuming ASU and greatly reduces the water gas shift process, which brings both advantages in the utilization of all raw materials and significant mitigation of CO2 emission. This system will be attractive in the regions of China which have abundant wind and coal resources.

  7. Optimum Crop Productivity in Rain Fed Area of Thana Boula Khan, Sindh, by Application of Wind Energy

    Directory of Open Access Journals (Sweden)

    Aneela Hameem Memon

    2014-08-01

    Full Text Available The energy and food security are crisis at global level. Various sources for generating energy are under exploitation but except of renewable energy are almost costly. Hence, proper exploration and exploitation renewable energy is cheaper in comparison of fossil fuels source. In this connection, wind energy source mostly is available in the southern region of Sindh province of Pakistan. Renewable energy and agricultural farming are a winning combination. Wind, solar, and biomass energy can be harvested forever, providing farmers with a long-term source of income. The net farm returns can significantly be enhanced if available stronger winds are effectively utilized as an alternative energy resource. The project has successfully been introduced by locally manufactured windmill driven pumping units. The wind speed probability analysis based upon limited data availability indicated that during almost 92% of operational time, a wind speed of 2.5 m/s (9 km/hr or more was available in project area. The operational analysis of windmill during 2007 indicated average 9.38 liter/min discharge was extracted, with role of 95.5 m 3 of water was pumped in Kharif season, which is sufficient to irrigate 0.096 hectare of land through surface irrigation method by maintaining 10 cm depth of applied water. However, modern and efficient irrigation methods like drip and sprinkler be employed alongside windmill introduction for getting optimum agricultural productivity.

  8. The Change in the Maximum Wind Speed and the Impact of it on Agricultural Production

    Institute of Scientific and Technical Information of China (English)

    WU Jian-mei; SUN Jin-sen; SUI Gui-ling; XIE Su-he; WANG Meng

    2012-01-01

    Using the data on the maximum wind speed within ten minutes every month in the period 1971-2009 in Zhucheng City of Shandong Province, we conduct statistical analysis of the maximum wind speed in Zhucheng City. The results show that over thirty-nine years, the annual maximum wind speed in four seasons in Zhucheng City tends to decline. The annual maximum wind speed declines at the rate of 1.45 m/s every 10 years. It falls fastest in winter, with decline rate of 1.73 m/s every 10 years; it is close to the average annual maximum wind speed in spring and autumn, with decline rate of 1.44 m/s and 14.8 m/s every 10 years, respectively; it falls slowest in summer, and the extreme value of the maximum wind speed occurs mainly in spring. The curve of changes in the monthly maximum wind speed in Zhucheng City assumes diminishing shape of "two peaks and one trough". We conduct preliminary analysis of the windy weather situation, and put forth specific defensive measures against the hazards of strong winds in the different periods.

  9. The Wind Energy in Power Production and Its Importance in Geography Teaching

    Science.gov (United States)

    Munkacsy, Bela

    2005-01-01

    Wind energy is an increasingly important factor of the power system in Europe. But it is still just a small part of the significant changes of the new millennium, namely the spreading of micro power and decentralisation of the whole energy system which are very important elements of sustainability. This paper shows the importance of wind power…

  10. Monitoring Snow Using Geostationary Satellite Retrievals During the SAAWSO Project

    Science.gov (United States)

    Rabin, Robert M.; Gultepe, Ismail; Kuligowski, Robert J.; Heidinger, Andrew K.

    2016-09-01

    The SAAWSO (Satellite Applications for Arctic Weather and SAR (Search And Rescue) Operations) field programs were conducted by Environment Canada near St. Johns, NL and Goose Bay, NL in the winters of 2012-13 and 2013-14, respectively. The goals of these programs were to validate satellite-based nowcasting products, including snow amount, wind intensity, and cloud physical parameters (e.g., cloud cover), over northern latitudes with potential applications to Search And Rescue (SAR) operations. Ground-based in situ sensors and remote sensing platforms were used to measure microphysical properties of precipitation, clouds and fog, radiation, temperature, moisture and wind profiles. Multi-spectral infrared observations obtained from Geostationary Operational Environmental Satellite (GOES)-13 provided estimates of cloud top temperature and height, phase (water, ice), hydrometer size, extinction, optical depth, and horizontal wind patterns at 15 min intervals. In this work, a technique developed for identifying clouds capable of producing high snowfall rates and incorporating wind information from the satellite observations is described. The cloud top physical properties retrieved from operational satellite observations are validated using measurements obtained from the ground-based in situ and remote sensing platforms collected during two precipitation events: a blizzard heavy snow storm case and a moderate snow event. The retrieved snow precipitation rates are found to be comparable to those of ground-based platform measurements in the heavy snow event.

  11. All sky imaging observations in visible and infrared waveband for validation of satellite cloud and aerosol products

    Science.gov (United States)

    Lu, Daren; Huo, Juan; Zhang, W.; Liu, J.

    A series of satellite sensors in visible and infrared wavelengths have been successfully operated on board a number of research satellites, e.g. NOAA/AVHRR, the MODIS onboard Terra and Aqua, etc. A number of cloud and aerosol products are produced and released in recent years. However, the validation of the product quality and accuracy are still a challenge to the atmospheric remote sensing community. In this paper, we suggest a ground based validation scheme for satellite-derived cloud and aerosol products by using combined visible and thermal infrared all sky imaging observations as well as surface meteorological observations. In the scheme, a visible digital camera with a fish-eye lens is used to continuously monitor the all sky with the view angle greater than 180 deg. The digital camera system is calibrated for both its geometry and radiance (broad blue, green, and red band) so as to a retrieval method can be used to detect the clear and cloudy sky spatial distribution and their temporal variations. A calibrated scanning thermal infrared thermometer is used to monitor the all sky brightness temperature distribution. An algorithm is developed to detect the clear and cloudy sky as well as cloud base height by using sky brightness distribution and surface temperature and humidity as input. Based on these composite retrieval of clear and cloudy sky distribution, it can be used to validate the satellite retrievals in the sense of real-simultaneous comparison and statistics, respectively. What will be presented in this talk include the results of the field observations and comparisons completed in Beijing (40 deg N, 116.5 deg E) in year 2003 and 2004. This work is supported by NSFC grant No. 4002700, and MOST grant No 2001CCA02200

  12. Effects of wake-turbine blade interactions on power production of wind turbines

    Science.gov (United States)

    Tadokoro, Maki; Yokoyama, Hiroshi; Iida, Akiyoshi

    2017-01-01

    In offshore wind farms, deterioration in power generation performance due to the mutual interference of flow around the wind turbines is a serious issue. To clarify the effects of wake-turbine blade interactions on the performance of wind farms, we conducted large-scale simulations of the flow around two full-scale wind turbines in a tandem-arrangement with two different spacings. The spacing between the two turbines was L/D = 1.0 and L/D = 2.0, with D being the rotor diameter. The predicted results show that vortices generated in the wake of the first turbine interfere with the blades of the second turbine and the interference becomes more intense for the case of L/D = 1.0. Thus, the power coefficient of the downstream turbine becomes lower by 80% for the case of L/D = 1.0 compared with the case of a single wind turbine.

  13. Generation of statistical scenarios of short-term wind power production

    DEFF Research Database (Denmark)

    Pinson, Pierre; Papaefthymiou, George; Klockl, Bernd;

    2007-01-01

    Short-term (up to 2-3 days ahead) probabilistic forecasts of wind power provide forecast users with a paramount information on the uncertainty of expected wind generation. Whatever the type of these probabilistic forecasts, they are produced on a per horizon basis, and hence do not inform...... on the development of the forecast uncertainty through forecast series. This issue is addressed here by describing a method that permits to generate statistical scenarios of wind generation that accounts for the interdependence structure of prediction errors, in plus of respecting predictive distributions of wind...... generation. The approach is evaluated on the test case of a multi-MW wind farm over a period of more than two years. Its interest for a large range of applications is discussed....

  14. Asynchronism in leaf and wood production in tropical forests: a study combining satellite and ground-based measurements

    Directory of Open Access Journals (Sweden)

    F. Wagner

    2013-11-01

    Full Text Available The fixation of carbon in tropical forests mainly occurs through the production of wood and leaves, both being the principal components of net primary production. Currently field and satellite observations are independently used to describe the forest carbon cycle, but the link between satellite-derived forest phenology and field-derived forest productivity remains opaque. We used a unique combination of a MODIS enhanced vegetation index (EVI dataset, a wood production model based on climate data and direct litterfall observations at an intra-annual timescale in order to question the synchronism of leaf and wood production in tropical forests. Even though leaf and wood biomass fluxes had the same range (respectively 2.4 ± 1.4 and 2.2 ± 0.4 Mg C ha−1 yr−1, they occurred separately in time. EVI increased with leaf renewal at the beginning of the dry season, when solar irradiance was at its maximum. At this time, wood production stopped. At the onset of the rainy season, when new leaves were fully mature and water available again, wood production quickly increased to reach its maximum in less than a month, reflecting a change in carbon allocation from short-lived pools (leaves to long-lived pools (wood. The time lag between peaks of EVI and wood production (109 days revealed a substantial decoupling between the leaf renewal assumed to be driven by irradiance and the water-driven wood production. Our work is a first attempt to link EVI data, wood production and leaf phenology at a seasonal timescale in a tropical evergreen rainforest and pave the way to develop more sophisticated global carbon cycle models in tropical forests.

  15. Wind Energy Markets, 2. edition

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-11-15

    The report provides an overview of the global market for wind energy, including a concise look at wind energy development in key markets including installations, government incentives, and market trends. Topics covered include: an overview of wind energy including the history of wind energy production and the current market for wind energy; key business drivers of the wind energy market; barriers to the growth of wind energy; key wind energy trends and recent developments; the economics of wind energy, including cost, revenue, and government subsidy components; regional and national analyses of major wind energy markets; and, profiles of key wind turbine manufacturers.

  16. Ground measurements of the hemispherical-directional reflectance of Arctic snow covered tundra for the validation of satellite remote sensing products

    Science.gov (United States)

    Ball, C. P.; Marks, A. A.; Green, P.; Mac Arthur, A.; Fox, N.; King, M. D.

    2013-12-01

    Surface albedo is the hemispherical and wavelength integrated reflectance over the visible, near infrared and shortwave infrared regions of the solar spectrum. The albedo of Arctic snow can be in excess of 0.8 and it is a critical component in the global radiation budget because it determines the proportion of solar radiation absorbed, and reflected, over a large part of the Earth's surface. We present here our first results of the angularly resolved surface reflectance of Arctic snow at high solar zenith angles (~80°) suitable for the validation of satellite remote sensing products. The hemispherical directional reflectance factor (HDRF) of Arctic snow covered tundra was measured using the GonioRAdiometric Spectrometer System (GRASS) during a three-week field campaign in Ny-Ålesund, Svalbard, in March/April 2013. The measurements provide one of few existing HDRF datasets at high solar zenith angles for wind-blown Arctic snow covered tundra (conditions typical of the Arctic region), and the first ground-based measure of HDRF at Ny-Ålesund. The HDRF was recorded under clear sky conditions with 10° intervals in view zenith, and 30° intervals in view azimuth, for several typical sites over a wavelength range of 400-1500 nm at 1 nm resolution. Satellite sensors such as MODIS, AVHRR and VIIRS offer a method to monitor the surface albedo with high spatial and temporal resolution. However, snow reflectance is anisotropic and is dependent on view and illumination angle and the wavelength of the incident light. Spaceborne sensors subtend a discrete angle to the target surface and measure radiance over a limited number of narrow spectral bands. Therefore, the derivation of the surface albedo requires accurate knowledge of the surfaces bidirectional reflectance as a function of wavelength. The ultimate accuracy to which satellite sensors are able to measure snow surface properties such as albedo is dependant on the accuracy of the BRDF model, which can only be assessed

  17. Cross-satellite comparison of operational land surface temperature products derived from MODIS and ASTER data over bare soil surfaces

    Science.gov (United States)

    Duan, Si-Bo; Li, Zhao-Liang; Cheng, Jie; Leng, Pei

    2017-04-01

    The collection 6 (C6) MODIS land surface temperature (LST) product is publicly available for the user community. Compared to the collection 5 (C5) MODIS LST product, the C6 MODIS LST product has been refined over bare soil pixels. Assessing the accuracy of the C6 MODIS LST product will help to facilitate the use of the LST product in various applications. In this study, we present a cross-satellite comparison to evaluate the accuracy of the C6 MODIS LST product (MOD11_L2) over bare soil surfaces under various atmospheric and surface conditions using the ASTER LST product as a reference. For comparison, the C5 MODIS LST product was also used in the analysis. The absolute biases (0.2-1.5 K) of the differences between the C6 MODIS LST and ASTER LST over bare soil surfaces are approximately two times less than those (0.6-3.8 K) of the differences between the C5 MODIS LST and ASTER LST. Furthermore, the RMSEs (0.7-2.3 K) over bare soil surfaces for the C6 MODIS LST are significantly smaller than those (0.9-4.2 K) for the C5 MODIS LST. These results indicate that the accuracy of the C6 MODIS LST product is much better than that of the C5 MODIS LST product. We recommend that the user community employs the C6 MODIS LST product in their applications.

  18. Flood and Landslide Applications of High Time Resolution Satellite Rain Products

    Science.gov (United States)

    Adler, Robert F.; Hong, Yang; Huffman, George J.

    2006-01-01

    Experimental, potentially real-time systems to detect floods and landslides related to heavy rain events are described. A key basis for these applications is high time resolution satellite rainfall analyses. Rainfall is the primary cause for devastating floods across the world. However, in many countries, satellite-based precipitation estimation may be the best source of rainfall data due to insufficient ground networks and absence of data sharing along many trans-boundary river basins. Remotely sensed precipitation from the NASA's TRMM Multi-satellite Precipitation Analysis (TMPA) operational system (near real-time precipitation at a spatial-temporal resolution of 3 hours and 0.25deg x 0.25deg) is used to monitor extreme precipitation events. Then these data are ingested into a macro-scale hydrological model which is parameterized using spatially distributed elevation, soil and land cover datasets available globally from satellite remote sensing. Preliminary flood results appear reasonable in terms of location and frequency of events, with implementation on a quasi-global basis underway. With the availability of satellite rainfall analyses at fine time resolution, it has also become possible to assess landslide risk on a near-global basis. Early results show that landslide occurrence is closely associated with the spatial patterns and temporal distribution of TRMM rainfall characteristics. Particularly, the number of landslides triggered by rainfall is related to rainfall climatology, antecedent rainfall accumulation, and intensity-duration of rainstorms. For the purpose of prediction, an empirical TMPA-based rainfall intensity-duration threshold is developed and shown to have skill in determining potential areas of landslides. These experimental findings, in combination with landslide surface susceptibility information based on satellite-based land surface information, form a starting point towards a potential operational landslide monitoring/warning system

  19. Satellite-Delivered Learning.

    Science.gov (United States)

    Arnall, Gail C.

    1987-01-01

    Discusses the application of satellite information delivery to training. Describes a new trend, horizontal programming. Also discusses vertical programming and in-house production of training materials. Lists vendors of satellite-based training. (CH)

  20. Assessment of GPM and TRMM Multi-Satellite Precipitation Products in Streamflow Simulations in a Data-Sparse Mountainous Watershed in Myanmar

    National Research Council Canada - National Science Library

    Fei Yuan; Limin Zhang; Khin Wah Wah Win; Liliang Ren; Chongxu Zhao; Yonghua Zhu; Shanhu Jiang; Yi Liu

    2017-01-01

    ...) final run and the TRMM Multi-satellite Precipitation Analysis 3B42V7 precipitation products, and their feasibility in streamflow simulations in the Chindwin River basin, Myanmar, from April 2014...

  1. Satellite Wind-Profile Techniques

    Science.gov (United States)

    1980-12-01

    ATS DIVISION ATTN: N. 3U,?UKI CH-1211 , GENEVA 20 SWITZERLAND SERVICIO HETEOROLOGICO DE LA ARMADA EDIFICIO LIBERTAD , PISO 15 COMODORO PY...Y CORBETA URUGUAY (1104) BUENOS AIRES REPUBLICA ARGENTINA DIRECTOR GENERAL SERVICIO METEOROLOGICO NACIONAL 25 DE MAYO 658 BUENOS AIRES... ARGENTINA LIBRARY, CSIRO DIV. ATMOSPHERIC PHYSICS STATION STREET ASPENDALE, 3195 VICTORIA, AUSTRALIA LIBRARIAN METEOROLOGY DEPT. UNIVERSITY OF

  2. Advantages of using satellite soil moisture estimates over precipitation products to assess regional vegetation water availability and activity

    Science.gov (United States)

    Chen, Tiexi

    2017-04-01

    To improve the understanding of water-vegetation relationships, direct comparative studies assessing the utility of satellite remotely sensed soil moisture, gridded precipitation products, and land surface model output are needed. A case study was investigated for a water-limited, lateral inflow receiving area in northeastern Australia during December 2008 to May 2009. In January 2009, monthly precipitation showed strong positive anomalies, which led to strong positive soil moisture anomalies. The precipitation anomalies disappeared within a month. In contrast, the soil moisture anomalies persisted for months. Positive anomalies of Normalized Difference Vegetation Index (NDVI) appeared in February, in response to water supply, and then persisted for several months. In addition to these temporal characteristics, the spatial patterns of NDVI anomalies were more similar to soil moisture patterns than to those of precipitation and land surface model output. The long memory of soil moisture mainly relates to the presence of clay-rich soils. Modeled soil moisture from four of five global land surface models failed to capture the memory length of soil moisture and all five models failed to present the influence of lateral inflow. This case study indicates that satellite-based soil moisture is a better predictor of vegetation water availability than precipitation in environments having a memory of several months and thus is able to persistently affect vegetation dynamics. These results illustrate the usefulness of satellite remotely sensed soil moisture in ecohydrology studies. This case study has the potential to be used as a benchmark for global land surface model evaluations. The advantages of using satellite remotely sensed soil moisture over gridded precipitation products are mainly expected in lateral-inflow and/or clay-rich regions worldwide.

  3. Are there urban signatures in the tropospheric ozone column products derived from satellite measurements?

    Directory of Open Access Journals (Sweden)

    J. Kar

    2010-06-01

    Full Text Available In view of the proposed geostationary satellite missions to monitor air quality from space, it is important to first assess the capability of the current suite of satellite instruments to provide information on the urban scale pollution. We explore the possibility of detecting urban signatures in the tropospheric column ozone data derived from Total Ozone Mapping Spectrometer (TOMS/Solar Backscattered Ultraviolet (SBUV and Ozone Monitoring Instrument (OMI/Microwave Limb Sounder (MLS satellite data. We find that distinct isolated plumes of tropospheric ozone near several large and polluted cities around the world may be detected in these data sets. The ozone plumes generally correspond with the tropospheric column NO2 plumes around these cities as observed by the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY instrument. Similar plumes are also seen in tropospheric mean ozone mixing ratio distribution after accounting for the surface and tropopause pressure variations. The total column ozone retrievals indicate fairly significant sensitivity to the lower troposphere over the polluted land areas, which might help explain these detections. These results indicate that ultraviolet (UV measurements may, in principle, be able to capture the urban signatures and may have implications for future missions using geostationary satellites.

  4. Propagation of Rainfall Products uncertainties in hydrological applications : Studies in the framework of the Megha-Tropiques Satellite Mission

    Science.gov (United States)

    Gosset, M.; Roca, R.

    2012-04-01

    The use of satellite based rainfall in research or operational Hydrological application is becoming more and more frequent. This is specially true in the Tropics where ground based gages (or radar) network are generally scarce and generally degrading. The new French-Indian satellite Mission Megha-Tropiques (MT) dedicated to the water and energy budget in the tropical atmosphere will contribute to a better monitoring of rainfall in the inter-tropical zone. As part of this mission, research is developed on the use of MT rainfall products for hydrological research or operational application such as flood monitoring. A key issue for such applications is how to account for rainfall products biases and uncertainties, and how to propagate them in the end user models ? Another important question is how to chose the best space-time resolution for the rainfall forcing, given that both model performances and rain-product uncertainties are resolution dependent. This talk will present on going investigations and perspectives on this subject, with examples from the Megha_tropiques Ground validation sites. Several sensitivity studies have been carried out in the Oueme Basin in Benin, West Africa, one the instrumented basin that will be used for MT products direct and hydrological validation.

  5. Modeling energy production of solar thermal systems and wind turbines for installation at corn ethanol plants

    Science.gov (United States)

    Ehrke, Elizabeth

    Nearly every aspect of human existence relies on energy in some way. Most of this energy is currently derived from fossil fuel resources. Increasing energy demands coupled with environmental and national security concerns have facilitated the move towards renewable energy sources. Biofuels like corn ethanol are one of the ways the U.S. has significantly reduced petroleum consumption. However, the large energy requirement of corn ethanol limits the net benefit of the fuel. Using renewable energy sources to produce ethanol can greatly improve its economic and environmental benefits. The main purpose of this study was to model the useful energy received from a solar thermal array and a wind turbine at various locations to determine the feasibility of applying these technologies at ethanol plants around the country. The model calculates thermal energy received from a solar collector array and electricity generated by a wind turbine utilizing various input data to characterize the equipment. Project cost and energy rate inputs are used to evaluate the profitability of the solar array or wind turbine. The current state of the wind and solar markets were examined to give an accurate representation of the economics of each industry. Eighteen ethanol plant locations were evaluated for the viability of a solar thermal array and/or wind turbine. All ethanol plant locations have long payback periods for solar thermal arrays, but high natural gas prices significantly reduce this timeframe. Government incentives will be necessary for the economic feasibility of solar thermal arrays. Wind turbines can be very profitable for ethanol plants in the Midwest due to large wind resources. The profitability of wind power is sensitive to regional energy prices. However, government incentives for wind power do not significantly change the economic feasibility of a wind turbine. This model can be used by current or future ethanol facilities to investigate or begin the planning process for a

  6. PTC and Partner Products in the Creation of a Hurricane Wind Sensor

    Science.gov (United States)

    Randazzo, John; Voska, N. (Technical Monitor)

    2002-01-01

    This viewgraph presentation provides information on the development of a wind sensor for use during hurricanes. The objectives of this presentation are: (1) Educate the user unfamiliar with the modules as to what is available/lacking; (2) Share where some changes could be made; (3) Look at alternative approaches made possible by new releases/modules; (4) Use feedback to improve processes/approaches. The current pad wind sensors are cup-and-vane type anemometers.

  7. Wind Energy

    Energy Technology Data Exchange (ETDEWEB)

    Beurskens, H.J.M. [SET Analysis, Kievitlaan 26, 1742 AD Schagen (Netherlands); Brand, A.J. [Energy research Centre of the Netherlands ECN, Unit Wind Energy, P.O. Box 1, 1755 ZG Petten (Netherlands)

    2013-02-15

    Over the years, wind energy has become a major source of renewable energy worldwide. The present chapter addresses the wind resource, which is available for exploitation for large-scale electricity production, and its specific physical properties. Furthermore, the technical options available to convert the energy of the air flow into mechanical energy and electricity are described. Specific problems of large-scale integration of wind energy into the grid as well as the present and future market developments are described in this chapter. Finally, environmental aspects are discussed briefly.

  8. Statistical modeling of phenological phases in Poland based on coupling satellite derived products and gridded meteorological data

    Science.gov (United States)

    Czernecki, Bartosz; Jabłońska, Katarzyna; Nowosad, Jakub

    2016-04-01

    The aim of the study was to create and evaluate different statistical models for reconstructing and predicting selected phenological phases. This issue is of particular importance in Poland where national-wide phenological monitoring was abandoned in the middle of 1990s and the reactivated network was established in 2006. Authors decided to evaluate possibilities of using a wide-range of statistical modeling techniques to create synthetic archive dataset. Additionally, a robust tool for predicting the most distinguishable phenophases using only free of charge data as predictors was created. Study period covers the years 2007-2014 and contains only quality-controlled dataset of 10 species and 14 phenophases. Phenological data used in this study originates from the manual observations network run by the Institute of Meteorology and Water Management - National Research Institute (IMGW-PIB). Three kind of data sources were used as predictors: (i) satellite derived products, (ii) preprocessed gridded meteorological data, and (iii) spatial properties (longitude, latitude, altitude) of the monitoring site. Moderate-Resolution Imaging Spectroradiometer (MODIS) level-3 vegetation products were used for detecting onset dates of particular phenophases. Following indices were used: Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Leaf Area Index (LAI), and Fraction of Photosynthetically Active Radiation (fPAR). Additionally, Interactive Multisensor Snow and Ice Mapping System (IMS) products were chosen to detect occurrence of snow cover. Due to highly noisy data, authors decided to take into account pixel reliability information. Besides satellite derived products (NDVI, EVI, FPAR, LAI, Snow cover), a wide group of observational data and agrometeorological indices derived from the European Climate Assessment & Dataset (ECA&D) were used as a potential predictors: cumulative growing degree days (GDD), cumulative growing precipitation days (GPD

  9. Role of neutral wind and storm time electric fields inferred from the storm time ionization distribution at low latitudes: in-situ measurements by Indian satellite SROSS-C2

    Directory of Open Access Journals (Sweden)

    P. Subrahmanyam

    2005-11-01

    Full Text Available Recently, there has been a renewal of interest in the study of the effects of solar weather events on the ionization redistribution and irregularity generation. The observed changes at low and equatorial latitudes are rather complex and are noted to be a function of location, the time of the storm onset and its intensity, and various other characteristics of the geomagnetic storms triggered by solar weather events. At these latitudes, the effects of geomagnetic storms are basically due to (a direct penetration of the magnetospheric electric fields to low latitudes, (b development of disturbance dynamo, (c changes in atmospheric neutral winds at ionospheric level and (d changes in neutral composition triggered by the storm time atmospheric heating.

    In the present study an attempt is made to further understand some of the observed storm time effects in terms of storm time changes in zonal electric fields and meridional neutral winds. For this purpose, observations made by the Retarding Potential Analyzer (RPA payload on board the Indian satellite SROSS-C2 are examined for four prominent geomagnetic storm events that occurred during the high solar activity period of 1997-2000. Available simultaneous observations, from the GPS satellite network, are also used. The daytime passes of SROSS-C2 have been selected to examine the redistribution of ionization in the equatorial ionization anomaly (EIA region. In general, EIA is observed to be weakened 12-24 h after the main phase onset (MPO of the storm. The storm time behaviour inferred by SROSS-C2 and the GPS satellite network during the geomagnetic storm of 13 November 1998, for which simultaneous observations are available, is found to be consistent. Storm time changes in the delay of received GPS signals are noted to be ~1-3 m, which is a significant component of the total delay observed on a quiet day.

    An attempt is made to identify and

  10. Relationship between wind speed and aerosol optical depth over remote ocean

    Directory of Open Access Journals (Sweden)

    R. G. Grainger

    2009-11-01

    Full Text Available The effect of wind speed on aerosol optical depth (AOD at 550 nm over remote ocean regions is investigated. Remote ocean regions are defined by the combination of AOD from satellite observation and wind direction from ECMWF. According to our definition, many oceanic regions cannot be taken as remote ocean regions due to long-range transportation of aerosols from continents. Highly correlated linear relationships are found in remote ocean regions with a wind speed range of 4–20 ms−1. The enhancement of AOD at high wind speed is explained as the increase of sea salt aerosol production.

  11. Assessing variability and long-term trends in burned area by merging multiple satellite fire products

    OpenAIRE

    Giglio, L.; Randerson, J. T.; van der Werf, G. R.; Kasibhatla, P. S.; Collatz, G. J.; D. C. Morton; R. S. DeFries

    2010-01-01

    Long term, high quality estimates of burned area are needed for improving both prognostic and diagnostic fire emissions models and for assessing feedbacks between fire and the climate system. We developed global, monthly burned area estimates aggregated to 0.5° spatial resolution for the time period July 1996 through mid-2009 using four satellite data sets. From 2001–2009, our primary data source was 500-m burned area maps produced using Moderate Resolution Imaging Spectroradiometer (...

  12. Operational Cloud-Motion Winds from Meteosat Infrared Images.

    Science.gov (United States)

    Schmetz, Johannes; Holmlund, Kenneth; Hoffman, Joel; Strauss, Bernard; Mason, Brian; Gaertner, Volker; Koch, Arno; van de Berg, Leo

    1993-07-01

    The displacement of clouds in successive satellite images reflects the atmospheric circulation at various scales. The main application of the satellite-derived cloud-motion vectors is their use as winds in the data analysis for numerical weather prediction. At low latitudes in particular they constitute an indispensible data source for numerical weather prediction.This paper describes the operational method of deriving cloud-motion winds (CMW) from the IR image (10.5 12.5 µm) of the European geostationary Meteostat satellites. The method is automatic, that is, the cloud tracking uses cross correlation and the height assignment is based on satellite observed brightness temperature and a forecast temperature profile. Semitransparent clouds undergo a height correction based on radiative forward calculations and simultaneous radiance observations in both the IR and water vapor (5.7 7.1 µm) channel. Cloud-motion winds are subject to various quality checks that include manual quality control as the last step. Typically about 3000 wind vectors are produced per day over four production cycles.This paper documents algorithm changes and improvements made to the operational CMWs over the last five years. The improvements are shown by long-term comparisons with both collocated radiosondes and the first guess of the forecast model of the European Centre for Medium-Range Weather Forecasts. In particular, the height assignment of a wind vector and radiance filtering techniques preceding the cloud tracking have ameliorated the errors in Meteostat winds. The slow speed bias of high-level CMWs (winds have been reduced from about 4 to 1.3 m s1 for a mean wind speed of 24 m s1. Correspondingly, the rms vectors error of Meteosat high-level CMWs decreased from about 7.8 to 5 m s1. Medium- and low-level CMWs were also significantly improved.

  13. An Evaluation of Satellite-Based and Re-Analysis Radiation Budget Datasets Using CERES EBAF Products

    Science.gov (United States)

    Gupta, Shashi; Stackhouse, Paul; Wong, Takmeng; Mikovitz, Colleen; Cox, Stephen; Zhang, Taiping

    2016-04-01

    Top-of-atmosphere (TOA) and surface radiative fluxes from CERES Energy Balanced and Filled (EBAF; Loeb et al., 2009; Kato et al. 2013) products are used to evaluate the performance of several widely used long-term radiation budget datasets. Two of those are derived from satellite observations and five more are from re-analysis products. Satellite-derived datasets are the NASA/GEWEX Surface and TOA Radiation Budget Dataset Release-3 and the ISCCP-FD Dataset. The re-analysis datasets are taken from NCEP-CFSR, ERA-Interim, Japanese Re-Analysis (JRA-55), MERRA and the newly released MERRA2 products. Close examination is made of the differences between MERRA and MERRA2 products for the purpose of identifying improvements achieved for MERRA2. Many of these datasets have undergone quality assessment under the GEWEX Radiative Flux Assessment (RFA) project. For the purposes of the present study, EBAF datasets are treated as reference and other datasets are compared with it. All-sky and clear-sky, SW and LW, TOA and surface fluxes are included in this study. A 7-year period (2001-2007) common to all datasets is chosen for comparisons of global and zonal averages, monthly and annual average timeseries, and their anomalies. These comparisons show significant differences between EBAF and the other datasets. Certain anomalies and trends observed in the satellite-derived datasets are attributable to corresponding features in satellite datasets used as input, especially ISCCP cloud properties. Comparisons of zonal averages showed significant differences especially over higher latitudes even when those differences are not obvious in the global averages. Special emphasis is placed on the analysis of the correspondence between spatial patterns of geographical distribution of the above fluxes on a 7-year average as well as on a month-by-month basis using the Taylor (2001) methodology. Results showed that for 7-year average fields correlation coefficients between spatial patterns

  14. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2001-01-01 to 2001-12-29 (NCEI Accession 0075816)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  15. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2005-12-30 to 2006-12-30 (NODC Accession 0075821)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  16. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2000-11-28 to 2000-12-31 (NCEI Accession 0075815)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  17. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2008-12-31 to 2009-12-31 (NODC Accession 0075825)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  18. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2009-12-31 to 2010-12-30 (NODC Accession 0075824)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  19. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2007-12-31 to 2008-12-31 (NODC Accession 0075823)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  20. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2001-12-29 to 2002-12-31 (NCEI Accession 0075817)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  1. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2003-12-29 to 2004-12-28 (NODC Accession 0075819)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  2. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2002-12-31 to 2003-12-29 (NODC Accession 0075818)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  3. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2004-12-28 to 2005-12-30 (NODC Accession 0075820)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  4. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2010-12-30 to 2011-12-29 (NODC Accession 0088492)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  5. NOAA Coral Reef Watch Operational Near-real-time Twice-weekly Global 50 km Satellite Coral Bleaching Thermal Stress Monitoring Product Suite from 2006-12-30 to 2007-12-31 (NODC Accession 0075822)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's polar-orbiting satellites measure SST around the globe in near-real-time, and Coral Reef Watch produces a suite of products derived from this set of satellite...

  6. Flood and Landslide Applications of Near Real-time Satellite Rainfall Products

    Science.gov (United States)

    Hong, Yang; Adler, Robert F.; Negri, Andrew; Huffman, George J.

    2007-01-01

    Floods and associated landslides are one of the most widespread natural hazards on Earth, responsible for tens of thousands of deaths and billions of dollars in property damage every year. During 1993-2002, over 1000 of the more than 2,900 natural disasters reported were due to floods. These floods and associated landslides claimed over 90,000 lives, affected over 1.4 billion people and cost about $210 billion. The impact of these disasters is often felt most acutely in less developed regions. In many countries around the world, satellite-based precipitation estimation may be the best source of rainfall data due to lack of surface observing networks. Satellite observations can be of essential value in improving our understanding of the occurrence of hazardous events and possibly in lessening their impact on local economies and in reducing injuries, if they can be used to create reliable warning systems in cost-effective ways. This article addressed these opportunities and challenges by describing a combination of satellite-based real-time precipitation estimation with land surface characteristics as input, with empirical and numerical models to map potential of landslides and floods. In this article, a framework to detect floods and landslides related to heavy rain events in near-real-time is proposed. Key components of the framework are: a fine resolution precipitation acquisition system; a comprehensive land surface database; a hydrological modeling component; and landslide and debris flow model components. A key precipitation input dataset for the integrated applications is the NASA TRMM-based multi-satellite precipitation estimates. This dataset provides near real-time precipitation at a spatial-temporal resolution of 3 hours and 0.25deg x 0.25deg. By careful integration of remote sensing and in-situ observations, and assimilation of these observations into hydrological and landslide/debris flow models with surface topographic information, prediction of useful

  7. Fort Carson Wind Resource Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Robichaud, R.

    2012-10-01

    This report focuses on the wind resource assessment, the estimated energy production of wind turbines, and economic potential of a wind turbine project on a ridge in the southeastern portion of the Fort Carson Army base.

  8. Identifying Stratospheric Air Intrusions and Associated Hurricane-Force Wind Events over the North Pacific Ocean

    Science.gov (United States)

    Malloy, Kelsey; Folmer, Michael J.; Phillips, Joseph; Sienkiewicz, Joseph M.; Berndt, Emily

    2017-01-01

    Motivation: Ocean data is sparse: reliance on satellite imagery for marine forecasting; Ocean Prediction Center (OPC) –“mariner’s weather lifeline”. Responsible for: Pacific, Atlantic, Pacific Alaska surface analyses –24, 48, 96 hrs.; Wind & wave analyses –24, 48, 96 hrs.; Issue warnings, make decisions, Geostationary Operational Environmental Satellite –R Series (now GOES-16), Compared to the old GOES: 3 times spectral resolution, 4 times spatial resolution, 5 times faster coverage; Comparable to Japanese Meteorological Agency’s Himawari-8, used a lot throughout this research. Research Question: How can integrating satellite data imagery and derived products help forecasters improve prognosis of rapid cyclogenesis and hurricane-force wind events? Phase I –Identifying stratospheric air intrusions: Water Vapor –6.2, 6.9, 7.3 micron channels; Airmass RGB Product; AIRS, IASI, NUCAPS total column ozone and ozone anomaly; ASCAT (A/B) and AMSR-2 wind data.

  9. The entropy production at the multi-fluid MHD solar wind termination shock

    Energy Technology Data Exchange (ETDEWEB)

    Fahr, Hans Joerg; Siewert, Mark [Argelander Institut fuer Astronomie, Universitaet Bonn, Auf dem Huegel 71, 53121 Bonn (Germany)

    2014-07-01

    It has become evident meanwhile that the MHD solar wind termination shock needs a multifluid theoretical approach to adequately describe the intertwisted physical complexity in the interaction between fields and particles. In this approach here we treat the passage of three separate fluids over the MHD shock, namely solar wind protons, pickup protons and electrons. Connected with the different downstream pressures of three fluids we also calculate the different fluid entropies that are produced at the shock passage. As we can show the most relevant contribution to the total particle entropy is connected with the electron pressure which actually by far dominates the downstream plasma pressure.

  10. Using Free Flow Energy Cumulation in Wind and Hydro Power Production

    OpenAIRE

    2016-01-01

    When approaching a conventional wind turbine, the air flow is slowed down and widened. This results in a loss of turbine efficiency. In order to exploit wind or water flow power as effectively as possible, it was suggested that the turbine should be placed inside a shroud, which consists of 4 wing-shaped surfaces. Two internal airfoils improve the turbine performance by speeding up the flow acting on the turbine blades, two external wings create a field of low pressure behind the turbine, thu...

  11. Wind and flux measurements in a windfarm co-located with agricultural production (Invited)

    Science.gov (United States)

    Takle, E. S.; Prueger, J. H.; Rajewski, D. A.; Lundquist, J. K.; Aitken, M.; Rhodes, M. E.; Deppe, A. J.; Goodman, F. E.; Carter, K. C.; Mattison, L.; Rabideau, S. L.; Rosenberg, A. J.; Whitfield, C. L.; Hatfield, J.

    2010-12-01

    Co-locating wind farms in pre-existing agricultural fields represents multiple land uses for which there may be interactions. Agricultural producers have raised questions about the possible impact of changes in wind speed and turbulence on pollination, dew formation, and conditions favorable for diseases. During summer 2010 we measured wind speed and surface fluxes within a wind farm that was co-located with a landscape covered by corn and soybeans in central Iowa. We erected four 9.14 m towers in corn fields upwind and downwind of lines of 1.5 MW turbines. All towers were instrumented with sonic anemometers at 6.45 m above ground, three-cup anemometers at 9.06 m ,and two temperature and relative humidity probes at 5.30 and 9.06 m. In addition, LiCor 7500 CO2/H2O flux analyzers were mounted at 6.45 m on two towers. At the beginning of the field campaign (late June) the corn had a height of about 1.3 m and grew to about 2.2 m at maturity in late July. For a 2-week period beginning late June a vertically pointing lidar was located near a flux tower downwind of one of the turbines and collected horizontal winds from 40 m to 200 m above ground. Twenty-Hz data from the eddy covariance systems were recorded as were 5-min averaged values of wind speed, temperature, humidity, and fluxes of heat, momentum, moisture and CO2 day and night under a wide variety of weather conditions, including a two-week period when the turbines were shut down. Numerical simulations with the WRF (Weather Research and Forecast) model for select periods with no turbine influence provide opportunities for comparing modeled and measured values of surface conditions and vertical wind profiles. Results show clear evidence of changes in flow field conditions at the surface that influence fluxes. We will discuss diurnal changes in fluxes and influence of turbines. Lidar measurements of vertical profiles of wind speed compared against modeled undisturbed flow fields behind a turbine reveal significant

  12. Effects of the partitioning of diffuse and direct solar radiation on satellite-based modeling of crop gross primary production

    Science.gov (United States)

    Xin, Qinchuan; Gong, Peng; Suyker, Andrew E.; Si, Yali

    2016-08-01

    Modeling crop gross primary production (GPP) is critical to understanding the carbon dynamics of agro-ecosystems. Satellite-based studies have widely used production efficiency models (PEM) to estimate cropland GPP, wherein light use efficiency (LUE) is a key model parameter. One factor that has not been well considered in many PEMs is that canopy LUE could vary with illumination conditions. This study investigates how the partitioning of diffuse and direct solar radiation influences cropland GPP using both flux tower and satellite data. The field-measured hourly LUE under cloudy conditions was 1.50 and 1.70 times higher than that under near clear-sky conditions for irrigated corn and soybean, respectively. We applied a two-leaf model to simulate the canopy radiative transfer process, where modeled photosynthetically active radiation (PAR) absorbed by canopy agreed with tower measurements (R2 = 0.959 and 0.914 for corn and soybean, respectively). Derived canopy LUE became similar after accounting for the impact of light saturation on leaf photosynthetic capacity under varied illumination conditions. The impacts of solar radiation partitioning on satellite-based modeling of crop GPP was examined using vegetation indices (VI) derived from MODIS data. Consistent with the field modeling results, the relationship between daily GPP and PAR × VI under varied illumination conditions showed different patterns in terms of regression slope and intercept. We proposed a function to correct the influences of direct and diffuse radiation partitioning and the explained variance of flux tower GPP increased in all experiments. Our results suggest that the non-linear response of leaf photosynthesis to light absorption contributes to higher canopy LUE on cloudy days than on clear days. We conclude that accounting for the impacts of solar radiation partitioning is necessary for modeling crop GPP on a daily or shorter basis.

  13. Correcting satellite-based precipitation products from SMOS soil moisture data assimilation using two models of different complexity

    Science.gov (United States)

    Román-Cascón, Carlos; Pellarin, Thierry; Gibon, François

    2017-04-01

    Real-time precipitation information at the global scale is quite useful information for many applications. However, satellite-based precipitation products in real time are known to be biased from real values observed in situ. On the other hand, the information about precipitation contained in soil moisture data can be very useful to improve precipitation estimation, since the evolution of this variable is highly influenced by the amount of rainfall at a certain area after a rain event. In this context, the soil moisture data from the Soil Moisture Ocean Salinity (SMOS) satellite is used to correct the precipitation provided by real-time satellite-based products such as CMORPH, TRMM-3B42RT or PERSIANN. In this work, we test an assimilation algorithm based on the data assimilation of SMOS measurements in two models of different complexity: a simple hydrological model (Antecedent Precipitation Index (API)) and a state-of-the-art complex land-surface model (Surface Externalisée (SURFEX)). We show how the assimilation technique, based on a particle filter method, leads to the improvement of correlation and root mean squared error (RMSE) of precipitation estimates, with slightly better results for the simpler (and less expensive computationally) API model. This methodology has been evaluated for six years in ten sites around the world with different features, showing the limitations of the methodology in regions affected by mountainous terrain or by high radio-frequency interferences (RFI), which notably affect the quality of the soil moisture retrievals from brightness temperatures by SMOS. The presented results are promising for a potential near-real time application at the global scale.

  14. Estimated Drag Coefficients and Wind Structure of Hurricane Frances

    Science.gov (United States)

    Zedler, S. E.; Niiler, P. P.; Stammer, D.; Terrill, E.

    2006-12-01

    As part of the Coupled Boundary Layers Air Sea Transfer (CBLAST) experiment, an array of drifters and floats was deployed from an aircraft just ahead of Hurricane Frances during it's passage to the northwest side of the Caribbean Island chain in August, 2004. The ocean and surface air conditions prior to, during, and after Hurricane Frances were documented by multiple sensors. Two independent estimates of the surface wind field suggest different storm structures. NOAA H*WINDS, an objectively analyzed product using a combination of data collected at the reconnaissance flight level, GPS profilers (dropwindsondes), satellites, and other data, suggest a 40km radius of maximum wind. A product based on the radial momentum equation balance using \\ital{in-situ} surface pressure data and wind direction measurements from the CBLAST drifter array suggests that the radius of maximum winds was 15km. We used a regional version of the MITGCM model with closed boundaries and realistic temperature and salinity fields which was forced with these wind field products to determine which wind field leads to circulation and SST structures that are most consistent with observed sea surface temperature fields and float profile data. Best estimates of the surface wind structure are then used to estimate the appropriate drag coefficient corresponding to the maximum velocity. Our results are compared with those obtained previously.

  15. Arctic wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, E. [Kemijoki Oy (Finland); Holttinen, H.; Marjaniemi, M. [VTT Energy, Espoo (Finland); Tammelin, B. [Finnish Meteorological Institute, Helsinki (Finland)

    1998-12-31

    Arctic wind energy research was aimed at adapting existing wind technologies to suit the arctic climatic conditions in Lapland. Project research work included meteorological measurements, instrument development, development of a blade heating system for wind turbines, load measurements and modelling of ice induced loads on wind turbines, together with the development of operation and maintenance practices in arctic conditions. As a result the basis now exists for technically feasible and economically viable wind energy production in Lapland. New and marketable products, such as blade heating systems for wind turbines and meteorological sensors for arctic conditions, with substantial export potential, have also been developed. (orig.)

  16. Discrepant estimates of primary and export production from satellite algorithms, a biogeochemical model, and geochemical tracer measurements in the North Pacific Ocean

    Science.gov (United States)

    Palevsky, Hilary I.; Quay, Paul D.; Nicholson, David P.

    2016-08-01

    Estimates of primary and export production (PP and EP) based on satellite remote sensing algorithms and global biogeochemical models are widely used to provide year-round global coverage not available from direct observations. However, observational data to validate these approaches are limited. We find that no single satellite algorithm or model can reproduce seasonal and annual geochemically determined PP, export efficiency (EP/PP), and EP rates throughout the North Pacific basin, based on comparisons throughout the full annual cycle at time series stations in the subarctic and subtropical gyres and basin-wide regions sampled by container ship transects. The high-latitude regions show large PP discrepancies in winter and spring and strong effects of deep winter mixed layers on annual EP that cannot be accounted for in current satellite-based approaches. These results underscore the need to evaluate satellite- and model-based estimates using multiple productivity parameters measured over broad ocean regions throughout the annual cycle.

  17. Satellite data assimilation in global forecast system in India

    Science.gov (United States)

    Basu, Swati

    2014-11-01

    Satellite data is very important for model initialization and verification. A large number of satellite observations are currently assimilated into the Numerical Weather Prediction (NWP) systems at the National Centre for Medium Range Weather Forecasting (NCMRWF). Apart from Global meteorological observations from GTS, near-real time satellite observations are received at NCMRWF from other operational centres like ISRO, NOAA/NESDIS, EUMETCAST, etc. Recently India has become member of Asia-Pacific Regional ATOVS Retransmission Service (APRARS) for faster access to high resolution global satellite data useful for high resolution regional models. Indian HRPT at Chennai covers the APRARS data gap region over South East Asia. A robust data monitoring system has been implemented at NCMRWF to assess the quantity and quality of the data as well as the satellite sensor strength, before getting assimilated in the models. Validation of new satellite observations, especially from Indian satellites are being carried out against insitu observations and similar space borne platforms. After establishing the quality of the data, Observation System Experiments (OSEs) are being conducted to study their impact in the assimilation and forecast systems. OSEs have been carried out with the Oceansat-2 scatterometer winds and radiance data from Megha-Tropiques SAPHIR sensor. Daily rainfall analysis dataset is being generated by merging satellite estimates and in-situ observations. ASCAT soil wetness measurements from METOP satellite is being assimilated into the global model. Land surface parameters (LuLc and albedo) retrieved from Indian satellites are being explored for its possible usage in the global and regional models. OLR from Indian satellites are used for validating model outputs. This paper reviews the efforts made at NCMRWF in (i) assimilating the data from Indian/International satellites and (ii) generating useful products from the satellite data.

  18. Turbulence and wind turbines

    DEFF Research Database (Denmark)

    Brand, Arno J.; Peinke, Joachim; Mann, Jakob

    2011-01-01

    The nature of turbulent flow towards, near and behind a wind turbine, the effect of turbulence on the electricity production and the mechanical loading of individual and clustered wind turbines, and some future issues are discussed.......The nature of turbulent flow towards, near and behind a wind turbine, the effect of turbulence on the electricity production and the mechanical loading of individual and clustered wind turbines, and some future issues are discussed....

  19. GHRSST Level 2P Gridded Global Subskin Sea Surface Temperature from WindSat polarimetric radiometer on the Coriolis satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains sea surface temperature derived from observations made by the WindSat Polarimetric Radiometer developed by the Naval Research Laboratory (NRL)...

  20. Comparison and evaluation of satellite- and reanalysis-based precipitation products for water resources management in the Brahmaputra River basin

    Science.gov (United States)

    Saleh Khan, Abu; Sohel Masud, Md.; Abdulla Hel Kafi, Md.; Sultana, Tashrifa; Lopez Lopez, Patricia

    2017-04-01

    The Brahmaputra River, with a transboundary basin area of approx. 554,500 km2, has its origin on the northern slope of the Himalayas in China, from where it flows through India, Bhutan and finally Bangladesh. Brahmaputra basin's climatology is heavily conditioned by precipitation during the monsoon months, concentrating about the 85 % of the rainfall in this period and originating severe and frequent floods that impact specially the Bangladeshi population in the delta region. Recent campaigns to increase the quality and to share ground-based hydro-meteorological data, in particular precipitation, within the basin have provided limited results. Global rainfall data from satellite and reanalysis may improve the temporal and spatial availability of in-situ observations for advanced water resources management. This study aims to evaluate the applicability of several global precipitation products from satellite and reanalysis in comparison with in-situ data to quantify their added value for hydrological modeling at a basin and sub-basin scale for the Brahmaputra River. Precipitation products from CMORPH, TRMM-3B42, GsMAP, WFDEI, MSWEP and various combinations with ground-based data were evaluated at basin and sub-basin level at a daily and monthly temporal resolution. The Brahmaputra was delineated into 54 sub-basins for a more detailed evaluation of the precipitation products. The data were analysed and inter-compared for the time period from 2002 to 2010. Precipitation performance assessment was conducted including several indicators, such as probability of detection (POD), false alarm ratio (FAR), Pearson's correlation coefficient (r), bias and root mean square error (RMSE). Preliminary results indicate high correlation and low bias and RMSE values between WFDEI, TRMM-3B42 and CMORPH precipitation and in-situ observations at a monthly time scale. Lower correlations and higher bias and RMSE values were found between GsMAP and MSWEP and ground-observed precipitation

  1. 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

  2. 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

  3. Renewable energy for electric power generation in Morocco : the wind farm at Koudia Al Baida; Des energies renouvelables dans le developpement de la production electrique au Maroc : le parc eolien de Koudia Al Baida

    Energy Technology Data Exchange (ETDEWEB)

    Boye, H. [General Electric (Morocco)

    2003-07-01

    This presentation describes the Koudia Al Baida wind farm in the village of Wilaya de Tetouan in Morocco. The total installed generating capacity of the wind farm is 50.4 MW, one of the largest in Africa and the Arab world. The Gibraltar straights region has an enormous wind potential, with average wind speeds of 10 metres per second for an annual electricity production of 4,000 hours. The wind farm consists of 44 identical turbines, each generating 600 kW of electricity. The turbines are manufactured in Denmark by Vestas. The technical specifications of the turbines were provided along with the project's installation and operating costs. The wind farm went into production in August 2000. The first years of production have been very successful. It was noted that since winds are not always reliable, the maximum wind contribution to the power grid should not exceed 7 to 10 per cent of total electricity production. tabs., figs.

  4. The precipitation products generation chain for the EUMETSAT Hydrological Satellite Application Facility at C.N.M.C.A.

    Science.gov (United States)

    Biron, Daniele; Melfi, Davide; Zauli, Francesco

    2008-08-01

    The EUMETSAT Satellite Application Facility in support to Hydrology (H-SAF) focuses on development of new geophysical products on precipitation, soil moisture and snow parameters and the utilisation of these parameters in hydrological models, NWP models and water management. The development phase of the H-SAF started in September 2005 under the leadership of Italian Meteorological Service. The "Centro Nazionale di Meteorologia e Climatologia Aeronautica (C.N.M.C.A.)", the Italian National Weather Centre, that physically hosts the generation chain of precipitation products, carried on activities to reach the final target: development of algorithms, validation of results, implementation of operative procedure to supply the service and to monitor the service performances. The paper shows the architectural status of the H-SAF precipitation group and stress the component of operations. It is shown the full correspondence with the EUMETSAT approved H-SAF documents, in particular the Algorithm Theoretical Design Document (ATDD), where products characteristics are referenced. Are also reported the first results, produced during the first H-SAF Workshop, held in Rome in October 2007, of validation activities performed on version 1 products, and last results of products distribution to beta-users in preparation of distributing version 2.

  5. Developing the science product algorithm testbed for Chinese next-generation geostationary meteorological satellites: Fengyun-4 series

    Science.gov (United States)

    Min, Min; Wu, Chunqiang; Li, Chuan; Liu, Hui; Xu, Na; Wu, Xiao; Chen, Lin; Wang, Fu; Sun, Fenglin; Qin, Danyu; Wang, Xi; Li, Bo; Zheng, Zhaojun; Cao, Guangzhen; Dong, Lixin

    2017-08-01

    Fengyun-4A (FY-4A), the first of the Chinese next-generation geostationary meteorological satellites, launched in 2016, offers several advances over the FY-2: more spectral bands, faster imaging, and infrared hyperspectral measurements. To support the major objective of developing the prototypes of FY-4 science algorithms, two science product algorithm testbeds for imagers and sounders have been developed by the scientists in the FY-4 Algorithm Working Group (AWG). Both testbeds, written in FORTRAN and C programming languages for Linux or UNIX systems, have been tested successfully by using Intel/g compilers. Some important FY-4 science products, including cloud mask, cloud properties, and temperature profiles, have been retrieved successfully through using a proxy imager, Himawari-8/Advanced Himawari Imager (AHI), and sounder data, obtained from the Atmospheric InfraRed Sounder, thus demonstrating their robustness. In addition, in early 2016, the FY-4 AWG was developed based on the imager testbed—a near real-time processing system for Himawari-8/AHI data for use by Chinese weather forecasters. Consequently, robust and flexible science product algorithm testbeds have provided essential and productive tools for popularizing FY-4 data and developing substantial improvements in FY-4 products.

  6. Importance of wind and river discharge in influencing nutrient dynamics and phytoplankton production in summer in the central Strait of Georgia

    DEFF Research Database (Denmark)

    Yin, K.D.; Goldblatt, R.H.; Harrison, P.J.;

    1997-01-01

    profiles of salinity, temperature, fluorescence and nutrients (nitrate and phosphate) were taken daily along a transect. A wind event occurred on August 7 and a rapid increase in the Fraser River discharge took place from August 8 to 14. The wind event mixed the water column and nutrients increased...... at the same time. Phytoplankton responded to the increase in nutrients and a bloom occurred soon after the wind event. The rapid increase in river discharge caused the entrainment of nitrate in the estuarine plume and, as a result, a subsurface maximum of chi a was developed. Our results clearly demonstrated...... that summer phytoplankton productivity in the central Strait of Georgia is fueled by a supply of nutrients from the nitracline through vertical mixing induced by the interaction of winds, river discharge and tidal cycles. Of these 3 factors, winds are the most variable and therefore a summer with frequent...

  7. Combining satellite observations to develop a daily global soil moisture product for a wide range of applications

    Science.gov (United States)

    Enenkel, M.; Reimer, C.; Dorigo, W.; Wagner, W.; Pfeil, I.; Parinussa, R.; De Jeu, R.

    2015-11-01

    The soil moisture dataset that is generated via the Climate Change Initiative (CCI) of the European Space Agency (ESA) (ESA CCI SM) is a popular research product. It is composed of observations from nine different satellites and aims to exploit the individual strengths of active (radar) and passive (radiometer) sensors, thereby providing surface soil moisture estimates at a spatial resolution of 0.25°. However, the annual updating cycle limits the use of the ESA CCI SM dataset for operational applications. Therefore, this study proposes an adaptation of the ESA CCI processing chain for daily global updates via satellite-derived near real-time (NRT) soil moisture observations. In order to extend the ESA CCI SM dataset from 1978 to present we use NRT observations from the Advanced SCATterometer on-board the MetOp satellites and the Advanced Microwave Scanning Radiometer 2 on-board GCOM-W. Since these NRT observations do not incorporate the latest algorithmic updates, parameter databases, and intercalibration efforts, by nature they offer a lower quality than reprocessed offline datasets. Our findings indicate that, despite issues in arid regions, the new "CCI NRT" dataset shows a good correlation with ESA CCI SM. The average global correlation coefficient between CCI NRT and ESA CCI SM (Pearson's R) is 0.8. An initial validation with 40 in-situ observations in France, Kenya, Senegal and Kenya yields an average R of 0.58 and 0.49 for ESA CCI SM and CCI NRT respectively. In summary, the CCI NRT dataset is getting ready for operational use, supporting applications such as drought and flood monitoring, weather forecasting or agricultural applications.

  8. Combining satellite observations to develop a daily global soil moisture product for a wide range of applications

    Directory of Open Access Journals (Sweden)

    M. Enenkel

    2015-11-01

    Full Text Available The soil moisture dataset that is generated via the Climate Change Initiative (CCI of the European Space Agency (ESA (ESA CCI SM is a popular research product. It is composed of observations from nine different satellites and aims to exploit the individual strengths of active (radar and passive (radiometer sensors, thereby providing surface soil moisture estimates at a spatial resolution of 0.25°. However, the annual updating cycle limits the use of the ESA CCI SM dataset for operational applications. Therefore, this study proposes an adaptation of the ESA CCI processing chain for daily global updates via satellite-derived near real-time (NRT soil moisture observations. In order to extend the ESA CCI SM dataset from 1978 to present we use NRT observations from the Advanced SCATterometer on-board the MetOp satellites and the Advanced Microwave Scanning Radiometer 2 on-board GCOM-W. Since these NRT observations do not incorporate the latest algorithmic updates, parameter databases, and intercalibration efforts, by nature they offer a lower quality than reprocessed offline datasets. Our findings indicate that, despite issues in arid regions, the new "CCI NRT" dataset shows a good correlation with ESA CCI SM. The average global correlation coefficient between CCI NRT and ESA CCI SM (Pearson's R is 0.8. An initial validation with 40 in-situ observations in France, Kenya, Senegal and Kenya yields an average R of 0.58 and 0.49 for ESA CCI SM and CCI NRT respectively. In summary, the CCI NRT dataset is getting ready for operational use, supporting applications such as drought and flood monitoring, weather forecasting or agricultural applications.

  9. CFD Study for the Optimization of the Drying Process of Foundry Moulds used in the Production of Wind Turbine Components

    Directory of Open Access Journals (Sweden)

    Giovanni Luca Di Muoio

    2015-02-01

    Full Text Available In order to drive down the cost of wind turbine cast components, the optimization of each production step is necessary. In particular, foundry moulds used for the production of cast components undergo a process of drying needed to avoid quality problems in the final parts. In order to reduce drying times forced convection by the use of fans is needed. In this work we perform Computational Fluid Dynamic studies with the aim to optimize the drying process for mould geometries typically used for the production of wind turbine components. Representative geometries are modelled in a 3D software, imported in a fluid flow solver and complete NavierStokes equations coupled with energy transport equations are solved. Velocity profiles from shop floor measurements are used as boundary conditions for the problem. Finally surface heat exchange coefficients are determined and results analyzed. Results show that it is possible to use this methodology to optimize the drying process, and determine areas of the moulds that are more difficult to dry than others. Optimal fan arrangement for typical geometries are also provided.

  10. Coupling of Wind Energy and Biogas with a High Temperature Steam Electrolyser for Hydrogen and Methane Production

    OpenAIRE

    Monnerie, Nathalie; Roeb, Martin; Houaijia, Anis; Sattler, Christian

    2014-01-01

    The production of environment friendly green fuels is based on energy from renewable sources. Among the renewable sources, wind power is a very growing power technology. An example which has been discussed very widely is hydrogen which is an ideal fuel for a fuel cell. Hydrogen is the energy of the future. It will be used as energy carrier as well as reactant to produce green fuels, like methane which is easier to handle. Direct coupling of a High Temperature Steam Electrolyser (HTSE) with a ...

  11. Wind Electrolysis: Hydrogen Cost Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Saur, G.; Ramsden, T.

    2011-05-01

    This report describes a hydrogen production cost analysis of a collection of optimized central wind based water electrolysis production facilities. The basic modeled wind electrolysis facility includes a number of low temperature electrolyzers and a co-located wind farm encompassing a number of 3MW wind turbines that provide electricity for the electrolyzer units.

  12. Habitat Size Optimization of the O'Neill - Glaser Economic Model for Space Solar Satellite Production

    Science.gov (United States)

    Curreri, Peter A.; Detweiler, Michael

    2010-01-01

    Creating large space habitats by launching all materials from Earth is prohibitively expensive. Using space resources and space based labor to build space solar power satellites can yield extraordinary profits after a few decades. The economic viability of this program depends on the use of space resources and space labor. To maximize the return on the investment, the early use of high density bolo habitats is required. Other shapes do not allow for the small initial scale required for a quick population increase in space. This study found that 5 Man Year, or 384 person bolo high density habitats will be the most economically feasible for a program started at year 2010 and will cause a profit by year 24 of the program, put over 45,000 people into space, and create a large system of space infrastructure for the further exploration and development of space.

  13. Development and characterization of composite materials for production of composite risers by filament winding

    Energy Technology Data Exchange (ETDEWEB)

    Sobrinho, L.L.; Bastian, F.L. [Federal University of Rio de Janeiro, RJ (Brazil). Dept. of Metallurgical and Materials Engineering], e-mail: ledjane@metalmat.ufrj.br; Calado, V.M.A. [Federal University of Rio de Janeiro, RJ (Brazil). Escola de Quimica

    2008-07-01

    Industry has been challenged to provide riser systems which are more cost effective and which can fill the technology gaps with respect to water depth, riser diameter and high temperatures left open by flexible, steel catenary risers (SCRs) and hybrid risers. Composite materials present advantages over conventional steel risers because composite materials are lighter, more fatigue and corrosion resistant, better thermal insulators and can be designed for improving the structural and mechanical response. Besides, composite materials present some attractive attributes for the offshore service, such as: high specific strength and stiffness. This paper focuses on the development and characterization of a polymer matrix (epoxy) and of material composite (epoxy/fiber glass), which will be used in a development for composites risers by the filament winding process (wet winding). (author)

  14. Increasing the technical and economic performance of wind diesel systems by including fresh water production

    DEFF Research Database (Denmark)

    Bindner, H.; Lundsager, P.

    1996-01-01

    In many remote regions of the world there is a lack of both electricity and potable water. In order to increase the standard of living and thus maintain the population both power and water have to be supplied at reasonable prices. A good option at many of these places are wind diesel systems...... of the Simple, Robust & Reliable (SR&R) type, [1], combined with a desalination system....

  15. Cloud parameters from zenith transmittances measured by sky radiometer at surface: Method development and satellite product validation

    Science.gov (United States)

    Khatri, Pradeep; Hayasaka, Tadahiro; Iwabuchi, Hironobu; Takamura, Tamio; Irie, Hitoshi; Nakajima, Takashi Y.; Letu, Husi; Kai, Qin

    2017-04-01

    Clouds are known to have profound impacts on atmospheric radiation and water budget, climate change, atmosphere-surface interaction, and so on. Cloud optical thickness (COT) and effective radius (Re) are two fundamental cloud parameters required to study clouds from climatological and hydrological point of view. Large spatial-temporal coverages of those cloud parameters from space observation have proved to be very useful for cloud research; however, validation of space-based products is still a challenging task due to lack of reliable data. Ground-based remote sensing instruments, such as sky radiometers distributed around the world through international observation networks of SKYNET (http://atmos2.cr.chiba-u.jp/skynet/) and AERONET (https://aeronet.gsfc.nasa.gov/) have a great potential to produce ground-truth cloud parameters at different parts of the globe to validate satellite products. Focusing to the sky radiometers of SKYNET and AERONET, a few cloud retrieval methods exists, but those methods have some difficulties to address the problem when cloud is optically thin. It is because the observed transmittances at two wavelengths can be originated from more than one set of COD and Re, and the choice of the most plausible set is difficult. At the same time, calibration issue, especially for the wavelength of near infrared (NIR) region, which is important to retrieve Re, is also a difficult task at present. As a result, instruments need to be calibrated at a high mountain or calibration terms need to be transferred from a standard instrument. Taking those points on account, we developed a new retrieval method emphasizing to overcome above-mentioned difficulties. We used observed transmittances of multiple wavelengths to overcome the first problem. We further proposed a method to obtain calibration constant of NIR wavelength channel using observation data. Our cloud retrieval method is found to produce relatively accurate COD and Re when validated them using

  16. Reducing the uncertainty in wind speed estimations near the coast

    Science.gov (United States)

    Floors, Rogier; Hahmann, Andrea N.; Karagali, Ioanna; Vasiljevic, Nikola; Lea, Guillaume; Simon, Elliot; Courtney, Michael; Ahsbahs, Tobias; Bay Hasager, Charlotte; Badger, Merete; Peña, Alfredo

    2016-04-01

    Many countries plan to meet renewable energy targets by installing near-shore wind farms, because of the high offshore wind speeds and good grid connectivity. Because of the strong relation between mean wind speed and the annual energy production, there is an interest in reducing uncertainty of the estimation of the wind speed in these coastal areas. The RUNE project aims to provide recommendations on the use of lidar systems and mesoscale models results to find the most effective (cost vs. accuracy) solution of estimating near-shore wind resources. Here we show some first results of the RUNE measuring campaign at the west coast of Jutland that started in December 2015. In this campaign, a long-range WindScanner system (a multi-lidar instrumentation) was used simultaneously with measurements from several vertical profiling lidars, a meteorological mast and an offshore buoy. These measurements result in a detailed picture of the flow in a transect across the coastline from approximately 5 km offshore up to 3 km inland. The wind speed obtained from a lidar in a sector-scanning mode and from two time-synchronized lidars that were separated horizontally but focused in the same point, will be compared. Furthermore it will be shown how the resulting horizontal wind speed transects compare with the wind speed measurements from the vertical profiling lidars and the meteorological mast. The behaviour of the coastal gradient in wind speed in this area is discussed. Satellite data for the wind over the RUNE measurement area were also collected. Synthetic Aperture Radar (SAR) winds from Sentinel-1 and TerraSAR-X were retrieved at different spatial resolutions. Advanced Scatterometer (ASCAT) swath winds were obtained from both METOP-A and B platforms. These were used for direct comparisons with the lidar in sector scanning mode.

  17. Applied Remote Sensing Education and Training (ARSET): Opportunities to shorten the learning curve in use of NASA satellite data products

    Science.gov (United States)

    Kleidman, R. G.; Prados, A. I.; Christopher, S. A.

    2010-12-01

    The previous decade has provided ample opportunity to use observations from space to constrain and enhance aerosol modeling efforts, but we find that the typical modeling professional outside of the immediate NASA environment is often overwhelmed by the breadth and depth of NASA satellite data products. NASA has invested in creating ARSET to help users learn and navigate through the maze of atmospheric products available. ARSET activities include training workshops which run from 1 to 5 days, creating educational materials and monthly air quality case study exercises in contest format. Our workshops provide what nobody else does: a clear and concise training on how to obtain and make proper use of atmospheric remote sensing products. Although our focus is on air quality applications we provide information that can be used by anyone wishing to understand and use atmospheric remote sensing products. All the materials we have used in our workshops as well as our educational materials and case studies are available at http://arset.gsfc.nasa.gov

  18. A Model For The Use Of Satellite Remote Sensing For The Measurement Of Primary Production In The Ocean

    Science.gov (United States)

    Collins, Donald J.; Kiefer, Dale A.; SooHoo, Janice B.; Stallings, Casson; Yang, Wei-Liang

    1986-08-01

    The estimation of oceanic primary production on a global scale is the focus of efforts in remote sensing using the Coastal Zone Color Scanner (CZCS). The goal of this research is to provide a measure of the primary production using only satellite data for the estimate. This estimate requires the measurement of surface pigments (chlorophyll a + phaeophytin a) using the CZCS, an estimate of the sea-surface temperature using the AVHRR and determination of the incident solar irradiance using GOES imagery. In this paper, we describe a model of primary production based upon the responses of phytoplankton to differing light and nutrient fields. This model includes the effects on production of variations in surface pigment concentration, the mixed layer depth and the dependence on the incident solar irradiance. The model has been tested using in situ data provided by the Southern California Bight Studies (Eppley, et al., 1979), California Cooperative Fisheries Investigations (CalCOFI), Organization of Persistent Upwelling Structures (J.B. Soolloo in OPUS Data Report) and other data sets. A synoptic measure of the distribution of surface pigments is derived from the West Coast Chlorophyll and Temperature Time Series (West Coast Time Series Advisory Group, 1985). The features and behavior of the model will be presented together with the results of the model verification.

  19. Fore- and nowcasting of the electricity production of wind turbines in complex terrain; Fore- und Nowcasting der Stromproduktion von Windenergieanlagen in komplexem Gelaende

    Energy Technology Data Exchange (ETDEWEB)

    Dierer, S.; Remund, J.; Schaffner, B. [Genossenschaft METEOTEST, Bern (Switzerland); Hug, Ch.; Stauch, V. [Federal Office of Meteorology and Climatology MeteoSwiss, Berne (Switzerland)

    2009-09-15

    In the research project 'Fore- and nowcasting of the electricity production of wind turbines in complex terrain' several forecast methods were developed and tested in a prototype. The forecasts were analysed for two temporal horizons: Short term forecasts for the next day as well as shortest term forecasts for intra-day trade. Hourly values of wind speed and power output were forecast. The following methods were developed and analysed: (i) Direct Model Output: Wind speed forecasts were directly adopted from MeteoSwiss's operational numerical weather model COSMO. Power output was derived using the theoretical power curve of each wind turbine. (ii) WindSim: WindSim is a high resolution model for simulating wind fields over complex terrain. The COSMO model's wind speed forecasts were transferred to hub height at the turbine sites based on wind fields calculated by WindSim. Power output was derived using the theoretical power curve of each wind turbine. (iii) Model Output Statistics: Based on historical data, linear relations between the forecast parameters and measured data (wind speed and power output) was determined for each site individually. Based on these, current COSMO forecast were transferred to wind speed and power output forecasts. (iv) Kalman Filter: Based on the local wind measurements of the last 24 hours, forecast errors were continuously updated and the COSMO forecasts were accordingly corrected. Power forecasts were calculated based on the empirical relation between measured wind speeds and power output at each site. These methods were developed successfully for short and shortest term forecasts. Despite the very complex terrain of Switzerland, the accuracy of the results is mostly in the range of or better than international reference values. On one hand, the developed methods display similar performances; on the other hand, they are based on different input data. This allows a certain flexibility for the development of operational

  20. An Icelandic wind atlas

    Science.gov (United States)

    Nawri, Nikolai; Nína Petersen, Gudrun; Bjornsson, Halldór; Arason, Þórður; Jónasson, Kristján

    2013-04-01

    While Iceland has ample wind, its use for energy production has been limited. Electricity in Iceland is generated from renewable hydro- and geothermal source and adding wind energy has not be considered practical or even necessary. However, adding wind into the energy mix is becoming a more viable options as opportunities for new hydro or geothermal power installation become limited. In order to obtain an estimate of the wind energy potential of Iceland a wind atlas has been developed as a part of the Nordic project "Improved Forecast of Wind, Waves and Icing" (IceWind). The atlas is based on mesoscale model runs produced with the Weather Research and Forecasting (WRF) Model and high-resolution regional analyses obtained through the Wind Atlas Analysis and Application Program (WAsP). The wind atlas shows that the wind energy potential is considerable. The regions with the strongest average wind are nevertheless impractical for wind farms, due to distance from road infrastructure and power grid as well as harsh winter climate. However, even in easily accessible regions wind energy potential in Iceland, as measured by annual average power density, is among the highest in Western Europe. There is a strong seasonal cycle, with wintertime power densities throughout the island being at least a factor of two higher than during summer. Calculations show that a modest wind farm of ten medium size turbines would produce more energy throughout the year than a small hydro power plants making wind energy a viable additional option.

  1. Wind turbines acoustic measurements

    Science.gov (United States)

    Trematerra, Amelia; Iannace, Gino

    2017-07-01

    The importance of wind turbines has increased over the last few years throughout the European Community. The European energy policy guidelines state that for the year 2020 20% of all energy must be produced by alternative energy sources. Wind turbines are an important type of energy production without petrol. A wind speed in a range from 2.5 m/s to 25.0 m/s is needed. One of the obstacles to the widespread diffusion of wind turbine is noise generation. This work presents some noise measurements of wind turbines in the South of Italy, and discusses the noise problems for the people living near wind farms.

  2. POMINO: An improved satellite NO2 product and impacts on emission inversio

    Science.gov (United States)

    Lin, J.; Liu, M.; Xin, J.; Boersma, K. F.; Spurr, R. J. D.; Martin, R.; Zhang, Q.

    2015-12-01

    Satellite retrievals of vertical column densities (VCDs) of tropospheric nitrogen dioxide (NO2) normally do not explicitly account for aerosol optical effects and surface reflectance anisotropy that vary with space and time. Here, we conduct an improved retrieval of NO2VCDs over China, POMINO, from the Ozone Monitoring Instrument (OMI) and test the importance of aerosol and surface reflectance treatments. POMINO uses a parallelized LIDORT-driven AMFv6 package to derive tropospheric air mass factors, taking slant column densities from DOMINO v2. Prerequisite cloud optical properties are retrieved with a consistent procedure. Aerosol optical properties are taken from GEOS-Chem simulations with subsequent MODIS-based AOD constraints. MODIS bi-directional reflectance distribution function (BRDF) data are used for surface reflectance over lands. Level-2 data for 2012 are aggregated into monthly means on a 0.25° long. x 0.25° lat. grid. POMINO-retrieved annual mean NO2 VCDs vary from 15-25 x 1015 cm-2 over the polluted North China Plain (NCP) to below 1015 cm-2 over much of west China. The subsequently-constrained Chinese annual anthropogenic emissions are 9.05 TgN yr-1, an increase from 2006 (Lin, 2012) by about 19%. Replacing the MODIS BRDF data with the OMLER v1 monthly climatological albedo data affects NO2 VCDs by up to 40% for certain locations and seasons. The effect on constrained NOx emissions is small. Assuming no aerosols in the retrieval process (as the traditional "implicit" treatment) enhances annual mean NO2 VCDs by 15-40% over much of east China. Seasonally, NO2 VCDs are reduced by 10-20% over parts of the NCP in spring and over north China in winter, despite the general enhancements in summer and fall. The effect on subsequently-constrained annual emissions is -5-30% with large seasonal and spatial dependence. The implicit aerosol treatment also tends to exclude days with high pollution, an important sampling bias. We conclude that the POMINO approach

  3. Meteosat SEVIRI Fire Radiative Power (FRP products from the Land Surface Analysis Satellite Applications Facility (LSA SAF – Part 1: Algorithms, product contents and analysis

    Directory of Open Access Journals (Sweden)

    M. J. Wooster

    2015-06-01

    Full Text Available Characterising changes in landscape scale fire activity at very high temporal resolution is best achieved using thermal observations of actively burning fires made from geostationary Earth observation (EO satellites. Over the last decade or more, a series of research and/or operational "active fire" products have been developed from these types of geostationary observations, often with the aim of supporting the generation of data related to biomass burning fuel consumption and trace gas and aerosol emission fields. The Fire Radiative Power (FRP products generated by the Land Surface Analysis Satellite Applications Facility (LSA SAF from data collected by the Meteosat Second Generation (MSG Spinning Enhanced Visible and Infrared Imager (SEVIRI are one such set of products, and are freely available in both near real-time and archived form. Every 15 min, the algorithms used to generate these products identify and map the location of new SEVIRI observations containing actively burning fires, and characterise their individual rates of radiative energy release (fire radiative power; FRP that is believed proportional to rates of biomass consumption and smoke emission. The FRP-PIXEL product contains the highest spatial resolution FRP dataset, delivered for all of Europe, northern and southern Africa, and part of South America at a spatial resolution of 3 km (decreasing away from the west African sub-satellite point at the full 15 min temporal resolution. The FRP-GRID product is an hourly summary of the FRP-PIXEL data, produced at a 5° grid cell size and including simple bias adjustments for meteorological cloud cover and for the regional underestimation of FRP caused, primarily, by the non-detection of low FRP fire pixels at SEVIRI's relatively coarse pixel size. Here we describe the enhanced geostationary Fire Thermal Anomaly (FTA algorithm used to detect the SEVIRI active fire pixels, and detail methods used to deliver atmospherically corrected FRP

  4. Relationship Between Satellite-Derived Snow Cover and Snowmelt-Runoff Timing and Stream Power in the Wind River Range, Wyoming

    Science.gov (United States)

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

    2010-01-01

    Earlier onset of springtime weather including earlier snowmelt has been documented in the western United States over at least the last 50 years. Because the majority (>70%) of the water supply in the western U.S. comes from snowmelt, analysis of the declining spring snowpack (and shrinking glaciers) has important implications for streamflow management. The amount of water in a snowpack influences stream discharge which can also influence erosion and sediment transport by changing stream power, or the rate at which a stream can do work such as move sediment and erode the stream bed. The focus of this work is the Wind River Range (WRR) in west-central Wyoming. Ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover, cloud- gap-filled (CGF) map products and 30 years of discharge and meteorological station data are studied. Streamflow data from six streams in the WRR drainage basins show lower annual discharge and earlier snowmelt in the decade of the 2000s than in the previous three decades, though no trend of either lower streamflow or earlier snowmelt was observed using MODIS snow-cover maps within the decade of the 2000s. Results show a statistically-significant trend at the 95% confidence level (or higher) of increasing weekly maximum air temperature (for three out of the five meteorological stations studied) in the decade of the 1970s, and also for the 40-year study period. MODIS-derived snow cover (percent of basin covered) measured on 30 April explains over 89% of the variance in discharge for maximum monthly streamflow in the decade of the 2000s using Spearman rank correlation analysis. We also investigated stream power for Bull Lake Creek Above Bull Lake from 1970 to 2009; a statistically-significant end toward reduced stream power was found (significant at the 90% confidence level). Observed changes in streamflow and stream power may be related to increasing weekly maximum air temperature measured during the 40-year study period. The

  5. Investigating the usefulness of satellite derived fluorescence data in inferring gross primary productivity within the carbon cycle data assimilation system

    Directory of Open Access Journals (Sweden)

    E. N. Koffi

    2015-01-01

    Full Text Available We investigate the utility of satellite measurements of chlorophyll fluorescence (Fs in constraining gross primary productivity (GPP. We ingest Fs measurements into the Carbon-Cycle Data Assimilation System (CCDAS which has been augmented by the fluorescence component of the Soil Canopy Observation, Photochemistry and Energy fluxes (SCOPE model. CCDAS simulates well the patterns of Fs suggesting the combined model is capable of ingesting these measurements. However simulated Fs is insensitive to the key parameter controlling GPP, the carboxylation capacity (Vcmax. Simulated Fs is sensitive to both the incoming absorbed photosynthetically active radiation (aPAR and leaf chlorophyll concentration both of which are treated as perfectly known in previous CCDAS versions. Proper use of Fs measurements therefore requires enhancement of CCDAS to include and expose these variables.

  6. Power from the Wind

    Science.gov (United States)

    Roman, Harry T.

    2004-01-01

    Wind energy is the fastest-growing renewable energy source in the world. Over the last 20 years, the wind industry has done a very good job of engineering machines, improving materials, and economies of production, and making this energy source a reality. Like all renewable energy forms, wind energy's successful application is site specific. Also,…

  7. Power from the Wind

    Science.gov (United States)

    Roman, Harry T.

    2004-01-01

    Wind energy is the fastest-growing renewable energy source in the world. Over the last 20 years, the wind industry has done a very good job of engineering machines, improving materials, and economies of production, and making this energy source a reality. Like all renewable energy forms, wind energy's successful application is site specific. Also,…

  8. A satellite anemometer

    Science.gov (United States)

    Hanson, W. B.; Heelis, R. A.

    1995-01-01

    This report describes the design, development, and testing of components of a satellite anemometer, an instrument for measuring neutral winds in the upper atmosphere from a satellite platform. The device, which uses four nearly identical pressure sensors, measures the angle of arrival of the bulk neutral flow in the satellite frame of reference. It could also be used in a feedback loop to control spacecraft attitude with respect to the ram velocity direction. We have now developed miniaturized ionization pressure gauges that will work well from the slip flow region near 115 km up to the base of the exosphere, which covers the entire altitude range currently being considered for Tether. Laboratory tests have demonstrated a very linear response to changes in ram angle out to +/- 20 deg. (transverse wind component of 2.7 km s(exp -1)) from the ram, and a monotonic response to out beyond 45 deg. Pitch (vertical wind) and yaw (horizontal wind) can be sampled simultaneously and meaningfully up to 10 Hz. Angular sensitivity of 30 arc seconds (approximately 1 ms(exp -1) is readily attainable, but absolute accuracy for winds will be approximately 1 deg (130 m/s) unless independent attitude knowledge is available. The critical elements of the design have all been tested in the laboratory.

  9. QuikSCAT and SSM/I ocean surface winds for wind energy

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Astrup, Poul; Nielsen, Per

    2007-01-01

    Ocean surface winds observed by satellite scatterometer (QuikSCAT) and passive microwave (SMM/I) provide valuable information for wind energy applications. In wind energy two long-term aspects on the offshore wind climate is of concern. One is the 20-year average necessary for the estimation...

  10. Sensitivity of Distributed Hydrologic Simulations to Ground and Satellite Based Rainfall Products

    OpenAIRE

    Singaiah Chintalapudi; Hatim O. Sharif; Hongjie Xie

    2014-01-01

    In this study, seven precipitation products (rain gauges, NEXRAD MPE, PERSIANN 0.25 degree, PERSIANN CCS-3hr, PERSIANN CCS-1hr, TRMM 3B42V7, and CMORPH) were used to force a physically-based distributed hydrologic model. The model was driven by these products to simulate the hydrologic response of a 1232 km2 watershed in the Guadalupe River basin, Texas. Storm events in 2007 were used to analyze the precipitation products. Comparison with rain gauge observations reveals that there were signif...

  11. Sensitivity of Distributed Hydrologic Simulations to Ground and Satellite Based Rainfall Products

    OpenAIRE

    Singaiah Chintalapudi; Hatim O. Sharif; Hongjie Xie

    2014-01-01

    In this study, seven precipitation products (rain gauges, NEXRAD MPE, PERSIANN 0.25 degree, PERSIANN CCS-3hr, PERSIANN CCS-1hr, TRMM 3B42V7, and CMORPH) were used to force a physically-based distributed hydrologic model. The model was driven by these products to simulate the hydrologic response of a 1232 km2 watershed in the Guadalupe River basin, Texas. Storm events in 2007 were used to analyze the precipitation products. Comparison with rain gauge observations reveals that there were signif...

  12. The Use of Multi-Source Satellite and Geospatial Data to Study the Effect of Urbanization of Primary Productivity in the United States

    Science.gov (United States)

    Imhoff, M. L.; Tucker, C. J.; Lawrence, W. T.; Stutzer, D.; Rusin, Robert

    2000-01-01

    Data from two different satellites, a digital land cover map, and digital census data were analyzed and combined in a geographic information system to study the effect of urbanization on photosynthetic vegetation productivity in the United States. Results show that urbanization can have a measurable but variable impact on the primary productivity of the land surface. Annual productivity can be reduced by as much as 20 days in some areas, but in resource limited regions, photosynthetic production can be enhanced by human activity. Overall, urban development reduces the productivity of the land surface and those areas with the highest productivity are directly in the path of urban sprawl.

  13. Calibration of a large-scale hydrological model using satellite-based soil moisture and evapotranspiration products

    Directory of Open Access Journals (Sweden)

    P. López López

    2017-06-01

    Full Text Available A considerable number of river basins around the world lack sufficient ground observations of hydro-meteorological data for effective water resources assessment and management. Several approaches can be developed to increase the quality and availability of data in these poorly gauged or ungauged river basins; among them, the use of Earth observations products has recently become promising. Earth observations of various environmental variables can be used potentially to increase knowledge about the hydrological processes in the basin and to improve streamflow model estimates, via assimilation or calibration. The present study aims to calibrate the large-scale hydrological model PCRaster GLOBal Water Balance (PCR-GLOBWB using satellite-based products of evapotranspiration and soil moisture for the Moroccan Oum er Rbia River basin. Daily simulations at a spatial resolution of 5  ×  5 arcmin are performed with varying parameters values for the 32-year period 1979–2010. Five different calibration scenarios are inter-compared: (i reference scenario using the hydrological model with the standard parameterization, (ii calibration using in situ-observed discharge time series, (iii calibration using the Global Land Evaporation Amsterdam Model (GLEAM actual evapotranspiration time series, (iv calibration using ESA Climate Change Initiative (CCI surface soil moisture time series and (v step-wise calibration using GLEAM actual evapotranspiration and ESA CCI surface soil moisture time series. The impact on discharge estimates of precipitation in comparison with model parameters calibration is investigated using three global precipitation products, including ERA-Interim (EI, WATCH Forcing methodology applied to ERA-Interim reanalysis data (WFDEI and Multi-Source Weighted-Ensemble Precipitation data by merging gauge, satellite and reanalysis data (MSWEP. Results show that GLEAM evapotranspiration and ESA CCI soil moisture may be used for model

  14. Calibration of a large-scale hydrological model using satellite-based soil moisture and evapotranspiration products

    Science.gov (United States)

    López López, Patricia; Sutanudjaja, Edwin H.; Schellekens, Jaap; Sterk, Geert; Bierkens, Marc F. P.

    2017-06-01

    A considerable number of river basins around the world lack sufficient ground observations of hydro-meteorological data for effective water resources assessment and management. Several approaches can be developed to increase the quality and availability of data in these poorly gauged or ungauged river basins; among them, the use of Earth observations products has recently become promising. Earth observations of various environmental variables can be used potentially to increase knowledge about the hydrological processes in the basin and to improve streamflow model estimates, via assimilation or calibration. The present study aims to calibrate the large-scale hydrological model PCRaster GLOBal Water Balance (PCR-GLOBWB) using satellite-based products of evapotranspiration and soil moisture for the Moroccan Oum er Rbia River basin. Daily simulations at a spatial resolution of 5 × 5 arcmin are performed with varying parameters values for the 32-year period 1979-2010. Five different calibration scenarios are inter-compared: (i) reference scenario using the hydrological model with the standard parameterization, (ii) calibration using in situ-observed discharge time series, (iii) calibration using the Global Land Evaporation Amsterdam Model (GLEAM) actual evapotranspiration time series, (iv) calibration using ESA Climate Change Initiative (CCI) surface soil moisture time series and (v) step-wise calibration using GLEAM actual evapotranspiration and ESA CCI surface soil moisture time series. The impact on discharge estimates of precipitation in comparison with model parameters calibration is investigated using three global precipitation products, including ERA-Interim (EI), WATCH Forcing methodology applied to ERA-Interim reanalysis data (WFDEI) and Multi-Source Weighted-Ensemble Precipitation data by merging gauge, satellite and reanalysis data (MSWEP). Results show that GLEAM evapotranspiration and ESA CCI soil moisture may be used for model calibration resulting in

  15. Improving daily streamflow forecasts in mountainous Upper Euphrates basin by multi-layer perceptron model with satellite snow products

    Science.gov (United States)

    Uysal, Gökçen; Şensoy, Aynur; Şorman, A. Arda

    2016-12-01

    This paper investigates the contribution of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite Snow Cover Area (SCA) product and in-situ snow depth measurements to Artificial Neural Network model (ANN) based daily streamflow forecasting in a mountainous river basin. In order to represent non-linear structure of the snowmelt process, Multi-Layer Perceptron (MLP) Feed-Forward Backpropagation (FFBP) architecture is developed and applied in Upper Euphrates River Basin (10,275 km2) of Turkey where snowmelt constitutes approximately 2/3 of total annual volume of runoff during spring and early summer months. Snowmelt season is evaluated between March and July; 7 years (2002-2008) seasonal daily data are used during training while 3 years (2009-2011) seasonal daily data are split for forecasting. One of the fastest ANN training algorithms, the Levenberg-Marquardt, is used for optimization of the network weights and biases. The consistency of the network is checked with four performance criteria: coefficient of determination (R2), Nash-Sutcliffe model efficiency (ME), root mean square error (RMSE) and mean absolute error (MAE). According to the results, SCA observations provide useful information for developing of a neural network model to predict snowmelt runoff, whereas snow depth data alone are not sufficient. The highest performance is experienced when total daily precipitation, average air temperature data are combined with satellite snow cover data. The data preprocessing technique of Discrete Wavelet Analysis (DWA) is coupled with MLP modeling to further improve the runoff peak estimates. As a result, Nash-Sutcliffe model efficiency is increased from 0.52 to 0.81 for training and from 0.51 to 0.75 for forecasting. Moreover, the results are compared with that of a conceptual model, Snowmelt Runoff Model (SRM), application using SCA as an input. The importance and the main contribution of this study is to use of satellite snow products and data

  16. Comparisons of Wind Speed Retrievals from an Airborne Microwave Radiometer (AMPR) with Satellite-Based Observations During the OLYMPEX/RADEX Field Campaign

    Science.gov (United States)

    Lang, Timothy J.; Biswas, Sayak

    2017-01-01

    AMPR is an airborne instrument that flew aboard the NASA ER-2 during the OLYMPEX/RADEX field campaign in late 2015. This poster's goal is to explore how well the instrument can retrieve near-surface wind speed over the ocean.

  17. Supporting Development of Satellite's Guidance Navigation and Control Software: A Product Line Approach

    Science.gov (United States)

    McComas, David; Stark, Michael; Leake, Stephen; White, Michael; Morisio, Maurizio; Travassos, Guilherme H.; Powers, Edward I. (Technical Monitor)

    2000-01-01

    The NASA Goddard Space Flight Center Flight Software Branch (FSB) is developing a Guidance, Navigation, and Control (GNC) Flight Software (FSW) product line. The demand for increasingly more complex flight software in less time while maintaining the same level of quality has motivated us to look for better FSW development strategies. The GNC FSW product line has been planned to address the core GNC FSW functionality very similar on many recent low/near Earth missions in the last ten years. Unfortunately these missions have not accomplished significant drops in development cost since a systematic approach towards reuse has not been adopted. In addition, new demands are continually being placed upon the FSW which means the FSB must become more adept at providing GNC FSW functionality's core so it can accommodate additional requirements. These domain features together with engineering concepts are influencing the specification, description and evaluation of FSW product line. Domain engineering is the foundation for emerging product line software development approaches. A product line is 'A family of products designed to take advantage of their common aspects and predicted variabilities'. In our product line approach, domain engineering includes the engineering activities needed to produce reusable artifacts for a domain. Application engineering refers to developing an application in the domain starting from reusable artifacts. The focus of this paper is regarding the software process, lessons learned and on how the GNC FSW product line manages variability. Existing domain engineering approaches do not enforce any specific notation for domain analysis or commonality and variability analysis. Usually, natural language text is the preferred tool. The advantage is the flexibility and adapt ability of natural language. However, one has to be ready to accept also its well-known drawbacks, such as ambiguity, inconsistency, and contradictions. While most domain analysis

  18. Supporting Development of Satellite's Guidance Navigation and Control Software: A Product Line Approach

    Science.gov (United States)

    McComas, David; Stark, Michael; Leake, Stephen; White, Michael; Morisio, Maurizio; Travassos, Guilherme H.; Powers, Edward I. (Technical Monitor)

    2000-01-01

    The NASA Goddard Space Flight Center Flight Software Branch (FSB) is developing a Guidance, Navigation, and Control (GNC) Flight Software (FSW) product line. The demand for increasingly more complex flight software in less time while maintaining the same level of quality has motivated us to look for better FSW development strategies. The GNC FSW product line has been planned to address the core GNC FSW functionality very similar on many recent low/near Earth missions in the last ten years. Unfortunately these missions have not accomplished significant drops in development cost since a systematic approach towards reuse has not been adopted. In addition, new demands are continually being placed upon the FSW which means the FSB must become more adept at providing GNC FSW functionality's core so it can accommodate additional requirements. These domain features together with engineering concepts are influencing the specification, description and evaluation of FSW product line. Domain engineering is the foundation for emerging product line software development approaches. A product line is 'A family of products designed to take advantage of their common aspects and predicted variabilities'. In our product line approach, domain engineering includes the engineering activities needed to produce reusable artifacts for a domain. Application engineering refers to developing an application in the domain starting from reusable artifacts. The focus of this paper is regarding the software process, lessons learned and on how the GNC FSW product line manages variability. Existing domain engineering approaches do not enforce any specific notation for domain analysis or commonality and variability analysis. Usually, natural language text is the preferred tool. The advantage is the flexibility and adapt ability of natural language. However, one has to be ready to accept also its well-known drawbacks, such as ambiguity, inconsistency, and contradictions. While most domain analysis

  19. Evaluation of ENVISAT ASAR data for sea surface wind retrieval in Hong Kong coastal waters of China

    Institute of Scientific and Technical Information of China (English)

    XU Qing; LIN Hui; ZHENG Quanan; XIU Peng; CHENG Yongcun; LIU Yuguang

    2008-01-01

    The C-band wind speed retrieval models,CMOD4,CMOD-IFR2,and CMODS were applied to retrieval of sea surface wind speeds from ENVISAT(European environmental satellite)ASAR(advanced synthetic aperture radar)data in the coastal waters near Hang Kong during a period from October 2005 to July 2007.The retrieved wind speeds are evaluated by comparing with buoy measurements and the QuikSCAT(quick scatterometer)wind products.The results show that the CMOD4 model gives the best performance at wind speeds lower than 15 m/s.The correlation coefficients with buoy and QuikSCAT winds are 0.781 and 0.896,respectively.The root mean square errors are the same 1.74m/s.Namely,the CMOD4 model is the best one for sea surface wind speed retrieval from ASAR data in the COastal waters near Hong Kong.

  20. Life cycle assessment of micro production technologies - solar cells, household wind turbines and micro motors; Livscyklusvurdering af mikroproduktionsteknologier - solceller, husstandsvindmoeller og mikromotorer

    Energy Technology Data Exchange (ETDEWEB)

    Faeborg Poulsen, A.; Kruse, H.; Hvid Ipsen, K.

    2000-07-15

    This report contains a life cycle based estimation of environmental effects of CHP based on the micro production technologies: solar cells, household wind turbines and micro motors. The technologies cover CHP production on very small plants which are characterised by being located by the individual consumer. (BA)

  1. Satellite-based products for forest fire prevention and recovery: the PREFER experience

    Science.gov (United States)

    Laneve, Giovanni; Bernini, Guido; Fusilli, Lorenzo; Marzialetti, Pablo

    2016-08-01

    PREFER is a three years projects funded in 2012 in the framework of the FP7 Emergency call. The project objective was to set up a space-based service infrastructure and up-to-date cartographic products, based on remote sensing data, to support the preparedness, prevention, recovery and reconstruction phases of the Forest Fires emergency cycle in the European Mediterranean Region. The products of PREFER were tested and evaluated during the training and the demonstration period of the project, which coincided with the forest fire season of 2015. The products were tested using the online PREFER service and the tests were linked to the pilot areas of the project which are Minho (Portugal), Messenia (Greece), Andalucía (Spain), Sardinia (Italy) and Corse (France). Testing was performed by members of the User Advisory Board (UAB) starting from the training event organized in Coimbra, Portugal in June 2015. The tests continued till the end of the fire season (October 2015) and the end users were provided with updated information for the areas of interest during the entire demonstration period. Due to data availability restrictions (in particular to ancillary required data) not all products were available for testing in all the test areas. However all the PREFER products were tested at least in one pilot area and in cooperation with at least one end user organization. It has to be mentioned that beyond the product suitability and usefulness to the end users the tests included evaluation of the usability of the web-based service of PREFER and the respective quality of service provided. This paper aims at presenting the results of the demonstration activity, the lessons learned and ideas for further enhancement of the developed products devoted to support prevention and recovery phases of the wildfire cycle.

  2. Development of arctic wind technology

    Energy Technology Data Exchange (ETDEWEB)

    Holttinen, H.; Marjaniemi, M.; Antikainen, P. [VTT Energy, Espoo (Finland)

    1998-10-01

    The climatic conditions of Lapland set special technical requirements for wind power production. The most difficult problem regarding wind power production in arctic regions is the build-up of hard and rime ice on structures of the machine

  3. Global Monitoring RSEM System for Crop Production by Incorporating Satellite-based Photosynthesis Rates and Anomaly Data of Sea Surface Temperature

    Science.gov (United States)

    Kaneko, D.; Sakuma, H.

    2014-12-01

    The first author has been developing RSEM crop-monitoring system using satellite-based assessment of photosynthesis, incorporating meteorological conditions. Crop production comprises of several stages and plural mechanisms based on leaf photosynthesis, surface energy balance, and the maturing of grains after fixation of CO2, along with water exchange through soil vegetation-atmosphere transfer. Grain production in prime countries appears to be randomly perturbed regionally and globally. Weather for crop plants reflects turbulent phenomena of convective and advection flows in atmosphere and surface boundary layer. It has been difficult for scientists to simulate and forecast weather correctly for sufficiently long terms to crop harvesting. However, severely poor harvests related to continental events must originate from a consistent mechanism of abnormal energetic flow in the atmosphere through both land and oceans. It should be remembered that oceans have more than 100 times of energy storage compared to atmosphere and ocean currents represent gigantic energy flows, strongly affecting climate. Anomalies of Sea Surface Temperature (SST), globally known as El Niño, Indian Ocean dipole, and Atlantic Niño etc., affect the seasonal climate on a continental scale. The authors aim to combine monitoring and seasonal forecasting, considering such mechanisms through land-ocean biosphere transfer. The present system produces assessments for all continents, specifically monitoring agricultural fields of main crops. Historical regions of poor and good harvests are compared with distributions of SST anomalies, which are provided by NASA GSFC. Those comparisons fairly suggest that the Worst harvest in 1993 and the Best in 1994 relate to the offshore distribution of low temperature anomalies and high gaps in ocean surface temperatures. However, high-temperature anomalies supported good harvests because of sufficient solar radiation for photosynthesis, and poor harvests because

  4. Satellite Based Soil Moisture Product Validation Using NOAA-CREST Ground and L-Band Observations

    Science.gov (United States)

    Norouzi, H.; Campo, C.; Temimi, M.; Lakhankar, T.; Khanbilvardi, R.

    2015-12-01

    Soil moisture content is among most important physical parameters in hydrology, climate, and environmental studies. Many microwave-based satellite observations have been utilized to estimate this parameter. The Advanced Microwave Scanning Radiometer 2 (AMSR2) is one of many remotely sensors that collects daily information of land surface soil moisture. However, many factors such as ancillary data and vegetation scattering can affect the signal and the estimation. Therefore, this information needs to be validated against some "ground-truth" observations. NOAA - Cooperative Remote Sensing and Technology (CREST) center at the City University of New York has a site located at Millbrook, NY with several insitu soil moisture probes and an L-Band radiometer similar to Soil Moisture Passive and Active (SMAP) one. This site is among SMAP Cal/Val sites. Soil moisture information was measured at seven different locations from 2012 to 2015. Hydra probes are used to measure six of these locations. This study utilizes the observations from insitu data and the L-Band radiometer close to ground (at 3 meters height) to validate and to compare soil moisture estimates from AMSR2. Analysis of the measurements and AMSR2 indicated a weak correlation with the hydra probes and a moder