Science.gov

Sample records for nasa-modified precipitation products

  1. NASA-modified precipitation products to improve USEPA nonpoint source water quality modeling for the Chesapeake Bay.

    PubMed

    Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

    2010-01-01

    The USEPA has estimated that over 20,000 water bodies within the United States do not meet water quality standards. One of the regulations in the Clean Water Act of 1972 requires states to monitor the total maximum daily load, or the amount of pollution that can be carried by a water body before it is determined to be "polluted," for any watershed in the United States (Copeland, 2005). In response to this mandate, the USEPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a decision support tool for assessing pollution and to guide the decision-making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program-Fortran (HSPF), computes continuous streamflow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events, especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA-modified/NOAA precipitation data. Using these data within HSPF, streamflow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better streamflow statistics and, potentially, in improved water quality assessment. PMID:20830927

  2. NASA-Modified Precipitation Products to Improve EPA Nonpoint Source Water Quality Modeling for the Chesapeake Bay

    NASA Technical Reports Server (NTRS)

    Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

    2010-01-01

    The Environmental Protection Agency (EPA) has estimated that over 20,000 water bodies within the United States do not meet water quality standards. Ninety percent of the impairments are typically caused by nonpoint sources. One of the regulations in the Clean Water Act of 1972 requires States to monitor the Total Maximum Daily Load (TMDL), or the amount of pollution that can be carried by a water body before it is determined to be "polluted", for any watershed in the U.S.. In response to this mandate, the EPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a Decision Support Tool (DST) for assessing pollution and to guide the decision making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program -- Fortran (HSPF), computes daily stream flow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA modified/NOAA precipitation data. Using these data within HSPF, stream flow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better stream flow statistics and, ultimately, in improved water quality assessment.

  3. Critical Precipitation Period for Dryland Maize Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grain yields for dryland corn (Zea mays L.) production in the semi-arid Great Plains of the United States can be very unpredictable because of the erratic nature of growing season precipitation. Because inputs costs for corn production can be very high, farmers need to have a tool that will help the...

  4. Critical Precipitation Period for Dryland Corn Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grain yields for dryland corn (Zea mays L.) production in the semi-arid Great Plains of the United States can be very unpredictable because of the erratic nature of growing season precipitation. Because inputs costs for corn production can be very high, farmers need to have a tool that will help the...

  5. Water Management Applications of Advanced Precipitation Products

    NASA Astrophysics Data System (ADS)

    Johnson, L. E.; Braswell, G.; Delaney, C.

    2012-12-01

    Advanced precipitation sensors and numerical models track storms as they occur and forecast the likelihood of heavy rain for time frames ranging from 1 to 8 hours, 1 day, and extended outlooks out to 3 to 7 days. Forecast skill decreases at the extended time frames but the outlooks have been shown to provide "situational awareness" which aids in preparation for flood mitigation and water supply operations. In California the California-Nevada River Forecast Centers and local Weather Forecast Offices provide precipitation products that are widely used to support water management and flood response activities of various kinds. The Hydrometeorology Testbed (HMT) program is being conducted to help advance the science of precipitation tracking and forecasting in support of the NWS. HMT high-resolution products have found applications for other non-federal water management activities as well. This presentation will describe water management applications of HMT advanced precipitation products, and characterization of benefits expected to accrue. Two case examples will be highlighted, 1) reservoir operations for flood control and water supply, and 2) urban stormwater management. Application of advanced precipitation products in support of reservoir operations is a focus of the Sonoma County Water Agency. Examples include: a) interfacing the high-resolution QPE products with a distributed hydrologic model for the Russian-Napa watersheds, b) providing early warning of in-coming storms for flood preparedness and water supply storage operations. For the stormwater case, San Francisco wastewater engineers are developing a plan to deploy high resolution gap-filling radars looking off shore to obtain longer lead times on approaching storms. A 4 to 8 hour lead time would provide opportunity to optimize stormwater capture and treatment operations, and minimize combined sewer overflows into the Bay.ussian River distributed hydrologic model.

  6. Precipitation products from the hydrology SAF

    NASA Astrophysics Data System (ADS)

    Mugnai, A.; Casella, D.; Cattani, E.; Dietrich, S.; Laviola, S.; Levizzani, V.; Panegrossi, G.; Petracca, M.; Sanò, P.; Di Paola, F.; Biron, D.; De Leonibus, L.; Melfi, D.; Rosci, P.; Vocino, A.; Zauli, F.; Pagliara, P.; Puca, S.; Rinollo, A.; Milani, L.; Porcù, F.; Gattari, F.

    2013-08-01

    The EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF) was established by the EUMETSAT Council on 3 July 2005, starting activity on 1 September 2005. The Italian Meteorological Service serves as Leading Entity on behalf of twelve European member countries. H-SAF products include precipitation, soil moisture and snow parameters. Some products are based only on satellite observations, while other products are based on the assimilation of satellite measurements/products into numerical models. In addition to product development and generation, H-SAF includes a product validation program and a hydrological validation program that are coordinated, respectively, by the Italian Department of Civil Protection and by the Polish Institute of Meteorology and Water Management. The National Center of Aeronautical Meteorology and Climatology (CNMCA) of the Italian Air Force is responsible for operational product generation and dissemination. In this paper we describe the H-SAF precipitation algorithms and products, which have been developed by the Italian Institute of Atmospheric Sciences and Climate (in collaboration with the international community) and by CNMCA during the Development Phase (DP, 2005-2010) and the first Continuous Development and Operations Phase (CDOP-1, 2010-2012). The precipitation products are based on passive microwave measurements obtained from radiometers onboard different sun-synchronous low-Earth-orbiting satellites (especially, the SSM/I and SSMIS radiometers onboard DMSP satellites and the AMSU-A + AMSU-B/MHS radiometer suites onboard EPS-MetOp and NOAA-POES satellites), as well as on combined infrared/passive microwave measurements in which the passive microwave precipitation estimates are used in conjunction with SEVIRI images from the geostationary MSG satellite. Moreover, the H-SAF product generation and dissemination chain and independent product validation activities are described. Also, the

  7. Enhanced precipitation variability decreases grass- and increases shrub-productivity

    PubMed Central

    Gherardi, Laureano A.; Sala, Osvaldo E.

    2015-01-01

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present results from a 6-y field experiment, where we applied sequences of wet and dry years, increasing interannual precipitation coefficient of variation while maintaining a precipitation amount constant. Increased precipitation variability significantly reduced ecosystem primary production. Dominant plant-functional types showed opposite responses: perennial-grass productivity decreased by 81%, whereas shrub productivity increased by 67%. This pattern was explained by different nonlinear responses to precipitation. Grass productivity presented a saturating response to precipitation where dry years had a larger negative effect than the positive effects of wet years. In contrast, shrubs showed an increasing response to precipitation that resulted in an increase in average productivity with increasing precipitation variability. In addition, the effects of precipitation variation increased through time. We argue that the differential responses of grasses and shrubs to precipitation variability and the amplification of this phenomenon through time result from contrasting root distributions of grasses and shrubs and competitive interactions among plant types, confirmed by structural equation analysis. Under drought conditions, grasses reduce their abundance and their ability to absorb water that then is transferred to deep soil layers that are exclusively explored by shrubs. Our work addresses an understudied dimension of climate change that might lead to widespread shrub encroachment reducing the provisioning of ecosystem services to society. PMID:26417095

  8. Enhanced precipitation variability decreases grass- and increases shrub-productivity.

    PubMed

    Gherardi, Laureano A; Sala, Osvaldo E

    2015-10-13

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present results from a 6-y field experiment, where we applied sequences of wet and dry years, increasing interannual precipitation coefficient of variation while maintaining a precipitation amount constant. Increased precipitation variability significantly reduced ecosystem primary production. Dominant plant-functional types showed opposite responses: perennial-grass productivity decreased by 81%, whereas shrub productivity increased by 67%. This pattern was explained by different nonlinear responses to precipitation. Grass productivity presented a saturating response to precipitation where dry years had a larger negative effect than the positive effects of wet years. In contrast, shrubs showed an increasing response to precipitation that resulted in an increase in average productivity with increasing precipitation variability. In addition, the effects of precipitation variation increased through time. We argue that the differential responses of grasses and shrubs to precipitation variability and the amplification of this phenomenon through time result from contrasting root distributions of grasses and shrubs and competitive interactions among plant types, confirmed by structural equation analysis. Under drought conditions, grasses reduce their abundance and their ability to absorb water that then is transferred to deep soil layers that are exclusively explored by shrubs. Our work addresses an understudied dimension of climate change that might lead to widespread shrub encroachment reducing the provisioning of ecosystem services to society. PMID:26417095

  9. An optimal merging technique for high-resolution precipitation products: OPTIMAL MERGING OF PRECIPITATION METHOD

    SciTech Connect

    Shrestha, Roshan; Houser, Paul R.; Anantharaj, Valentine G.

    2011-04-01

    Precipitation products are currently available from various sources at higher spatial and temporal resolution than any time in the past. Each of the precipitation products has its strengths and weaknesses in availability, accuracy, resolution, retrieval techniques and quality control. By merging the precipitation data obtained from multiple sources, one can improve its information content by minimizing these issues. However, precipitation data merging poses challenges of scale-mismatch, and accurate error and bias assessment. In this paper we present Optimal Merging of Precipitation (OMP), a new method to merge precipitation data from multiple sources that are of different spatial and temporal resolutions and accuracies. This method is a combination of scale conversion and merging weight optimization, involving performance-tracing based on Bayesian statistics and trend-analysis, which yields merging weights for each precipitation data source. The weights are optimized at multiple scales to facilitate multiscale merging and better precipitation downscaling. Precipitation data used in the experiment include products from the 12-km resolution North American Land Data Assimilation (NLDAS) system, the 8-km resolution CMORPH and the 4-km resolution National Stage-IV QPE. The test cases demonstrate that the OMP method is capable of identifying a better data source and allocating a higher priority for them in the merging procedure, dynamically over the region and time period. This method is also effective in filtering out poor quality data introduced into the merging process.

  10. No downshifts in productivity-precipitation relationships in multi-year precipitation-reduction experiments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precipitation is a key driver of ecosystem net primary productivity and carbon cycling. Global warming is altering precipitation patterns globally, and longer and more intense drought episodes are projected for many temperate and Mediterranean regions. The challenge of predicting the effects of alt...

  11. SEPARATION OF FISSION PRODUCTS FROM PLUTONIUM BY PRECIPITATION

    DOEpatents

    Seaborg, G.T.; Thompson, S.G.; Davidson, N.R.

    1959-09-01

    Fission product separation from hexavalent plutonium by bismuth phosphate precipitation of the fission products is described. The precipitation, according to this invention, is improved by coprecipitating ceric and zirconium phosphates (0.05 to 2.5 grams/liter) with the bismuth phosphate.

  12. Understanding Oceanic Heavy Precipitation Using Scatterometer, Satellite Precipitation, and Reanalysis Products

    NASA Technical Reports Server (NTRS)

    Garg, Piyush; Nesbitt, Stephen W.; Lang, Timothy J.; Chronis, Themis

    2016-01-01

    The primary aim of this study is to understand the heavy precipitation events over Oceanic regions using vector wind retrievals from space based scatterometers in combination with precipitation products from satellite and model reanalysis products. Heavy precipitation over oceans is a less understood phenomenon and this study tries to fill in the gaps which may lead us to a better understanding of heavy precipitation over oceans. Various phenomenon may lead to intense precipitation viz. MJO (Madden-Julian Oscillation), Extratropical cyclones, MCSs (Mesoscale Convective Systems), that occur inside or outside the tropics and if we can decipher the physical mechanisms behind occurrence of heavy precipitation, then it may lead us to a better understanding of such events which further may help us in building more robust weather and climate models. During a heavy precipitation event, scatterometer wind observations may lead us to understand the governing dynamics behind that event near the surface. We hypothesize that scatterometer winds can observe significant changes in the near-surface circulation and that there are global relationships among these quantities. To the degree to which this hypothesis fails, we will learn about the regional behavior of heavy precipitation-producing systems over the ocean. We use a "precipitation feature" (PF) approach to enable statistical analysis of a large database of raining features.

  13. Global Precipitation Measurement (GPM) Mission: Precipitation Processing System (PPS) GPM Mission Gridded Text Products Provide Surface Precipitation Retrievals

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz; Kelley, O.; Kummerow, C.; Huffman, G.; Olson, W.; Kwiatkowski, J.

    2015-01-01

    In February 2015, the Global Precipitation Measurement (GPM) mission core satellite will complete its first year in space. The core satellite carries a conically scanning microwave imager called the GPM Microwave Imager (GMI), which also has 166 GHz and 183 GHz frequency channels. The GPM core satellite also carries a dual frequency radar (DPR) which operates at Ku frequency, similar to the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar, and a new Ka frequency. The precipitation processing system (PPS) is producing swath-based instantaneous precipitation retrievals from GMI, both radars including a dual-frequency product, and a combined GMIDPR precipitation retrieval. These level 2 products are written in the HDF5 format and have many additional parameters beyond surface precipitation that are organized into appropriate groups. While these retrieval algorithms were developed prior to launch and are not optimal, these algorithms are producing very creditable retrievals. It is appropriate for a wide group of users to have access to the GPM retrievals. However, for researchers requiring only surface precipitation, these L2 swath products can appear to be very intimidating and they certainly do contain many more variables than the average researcher needs. Some researchers desire only surface retrievals stored in a simple easily accessible format. In response, PPS has begun to produce gridded text based products that contain just the most widely used variables for each instrument (surface rainfall rate, fraction liquid, fraction convective) in a single line for each grid box that contains one or more observations.This paper will describe the gridded data products that are being produced and provide an overview of their content. Currently two types of gridded products are being produced: (1) surface precipitation retrievals from the core satellite instruments GMI, DPR, and combined GMIDPR (2) surface precipitation retrievals for the partner constellation

  14. Quantitative precipitation estimation by merging multiple precipitation products using artificial neural networks

    NASA Astrophysics Data System (ADS)

    Chiang, Y.; Tsai, M.; Chang, F.

    2010-12-01

    Simulation of extreme rainfall-runoff events is the key issue for flood mitigation. The accuracy of flood forecasting driven from models is usually dependent on whether the upstream precipitation information is sufficient or not. In the past, such information was provided by ground measurements. However, remote sensing data such as radar and satellite images have been widely applied to precipitation estimation in recent years. The development of remotely sensed technology enables researchers to realize the spatial distribution of rainfall. As far as quantitative precipitation estimation is concerned, remote sensing data provide more useful information than ground measurements. It will have potential advantage of reducing the flood risk if ground observations and radar and satellite estimations can be appropriately integrated. Therefore, we first analyze the long-term variation and the correlation between observations and different products by statistical methods in this study. Secondly, the observational/ estimated errors of different precipitation sources are investigated and the biases of each precipitation products are removed by artificial neural networks. Finally, accurate quantitative precipitation estimation can be built by integrating different precipitation products.

  15. An optimal merging technique for high-resolution precipitation products

    SciTech Connect

    Houser, Paul

    2011-01-01

    Precipitation products are currently available from various sources at higher spatial and temporal resolution than any time in the past. Each of the precipitation products has its strengths and weaknesses in availability, accuracy, resolution, retrieval techniques and quality control. By merging the precipitation data obtained from multiple sources, one can improve its information content by minimizing these issues. However, precipitation data merging poses challenges of scale-mismatch, and accurate error and bias assessment. In this paper we present Optimal Merging of Precipitation (OMP), a new method to merge precipitation data from multiple sources that are of different spatial and temporal resolutions and accuracies. This method is a combination of scale conversion and merging weight optimization, involving performance-tracing based on Bayesian statistics and trend-analysis, which yields merging weights for each precipitation data source. The weights are optimized at multiple scales to facilitate multiscale merging and better precipitation downscaling. Precipitation data used in the experiment include products from the 12-km resolution North American Land Data Assimilation (NLDAS) system, the 8-km resolution CMORPH and the 4-km resolution National Stage-IV QPE. The test cases demonstrate that the OMP method is capable of identifying a better data source and allocating a higher priority for them in the merging procedure, dynamically over the region and time period. This method is also effective in filtering out poor quality data introduced into the merging process.

  16. A Global Error Model for Satellite Precipitation Products

    NASA Astrophysics Data System (ADS)

    Maggioni, V.; Sapiano, M.; Adler, R. F.; Huffman, G. J.

    2014-12-01

    The PUSH (Precipitation Uncertainties for Satellite Hydrology) error scheme is presented to provide global estimates of errors for high time resolution, merged precipitation products. Each of the following four scenarios is explored and explicitly modeled: correct no-precipitation detection (both satellite and gauges detect no precipitation), missed precipitation (satellite records a zero, but it is incorrect), false alarm (satellite detects precipitation, but the reference is zero), and hit (both satellite and gauges detect precipitation). Previous studies have shown that PUSH was able to reproduce the probability density functions of the benchmark precipitation, to capture missed precipitation and false detection uncertainties, and to reproduce the spatial pattern of the error over the Oklahoma region. This study shows how this framework can be generalized to other regions of the world, based on information that is available anywhere anytime. This will be exceptionally crucial in un-gauged regions of the world, where satellite retrievals represent the only available precipitation estimate on which hydrological applications (e.g., flood forecasting) and water resources management can rely. A methodology to discern the systematic and random components of the error is also investigated.

  17. Extreme precipitation patterns reduced terrestrial ecosystem production across biomes

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Moran, S. M.; Nearing, M.; Ponce Campos, G. E.; Huete, A. R.; Buda, A. R.; Bosch, D. D.; Gunter, S. A.; Kitchen, S. G.; McNab, W.; Morgan, J. A.; McClaran, M. P.; Montoya, D. S.; Peters, D. P.; Starks, P. J.

    2012-12-01

    Precipitation regimes are predicted to shift to more extreme patterns that are characterized by more intense rainfall events and longer dry intervals, yet their ecological impacts on vegetation production remain uncertain across biomes in natural climatic conditions. This in situ study investigated the effects of novel climatic conditions on aboveground net primary production (ANPP) by combining a greenness index from satellite measurements and climatic records during 2000 to 2009 from 11 long-term experimental sites in multiple biomes and climates. Results showed that extreme precipitation patterns decreased the sensitivity of ANPP to total annual precipitation (PT), at the regional and decadal scales, leading to a mean 20% decrease in rain-use efficiency across biomes. Relative decreases in ANPP were greatest for arid grassland (16%) and Mediterranean forest (20%), and less for mesic grassland and temperate forest (3%). The co-occurrence of more heavy rainfall events and longer dry intervals caused greater water stress that resulted in reduced vegetation production. A new generalized model was developed to improve predictions of the ANPP response to changes in extreme precipitation patterns by using a function of both PT and an index of precipitation extremes. These findings suggest that extreme precipitation patterns have more substantial and complex effects on vegetation production across biomes, and are as important as total annual precipitation in understanding vegetation processes. With predictions of more extreme weather events, forecasts of ecosystem production should consider these non-linear responses to altered precipitation patterns associated with climate change. Figure. Relation of production across precipitation gradients for 11 sites for two groups (Low: R95p% < 20%, High: R95p% ≥ 20%). See Table 2 for R95p% definitions. The relations were significantly different for the two groups (F2, 106 = 18.51, P < 0.0001).

  18. Comparisons of Satellite Derived Precipitation Products with Multisensor Precipitation Estimation over Southeast United States

    NASA Astrophysics Data System (ADS)

    Prakash, O.; Curtis, D. C.; Parames, P. M.; Harris, D. J.

    2011-12-01

    Satellite-based precipitation estimates with high spatial and temporal resolution, large areal coverage and freely available global data provides a potential alternative source of precipitation data for areas where ground-based precipitation networks are sparse or nonexistent, particularly in the developing countries. This study compares three satellite-derived precipitation products (e.g., TMPA-V6, PERSIANN and CMORPH) and one radar-derived product (MPE data) for the time period from March 2009 to April 2009. We applied the Hovmöller diagrams approach to see the spatial and temporal patterns of the various satellite data products and to identify the storm events falling under the computation domain/basin. The zonal Hovmöller diagrams, a comparative analysis of the radar-derived rainfall rate with the satellite derived rainfall rate shows that the spatial and temporal patterns in the TMPA-V6 rainfall rate generally agree with the MPE rainfall rate. Moreover, the TMPA-V6 precipitation events match closely with MPE events, whereas the PERSIANN data are showing more storm events and magnitude than the MPE. However, in this case, CMORPH data products are estimating very poor storm patterns and magnitude. This study also compares mean areal precipitation (MAP) estimates derived from the above said four data sources and duration. ArcGIS tool was used to compute the MAP for every 3-hour duration over Apalachicola-Chattahoochee-Flint River Basin (ACF), United States. The analysis indicates that basin-wide mean area precipitation estimates from satellite-derived TMPA-V6 and PERSIANN data tend to under-estimate the rainfall throughout the two-month analysis. The peaking time trend of satellite data follows the trend of MPE data closely over ACF basin. The cumulative rainfall plots show that the PERSIANN data were less negatively biased than TRMM. However, on an event-by-event basis, satellite methods overestimated in some cases and in some cases underestimated

  19. Assessment of the Consistency among Precipitation Products over Arid Regions

    NASA Astrophysics Data System (ADS)

    Ghebreyesus, Dawit; Temimi, Marouane

    2016-04-01

    This study addresses the analysis of the consistency among global precipitation products over arid regions. First, precipitation products were examined against in situ observations from the UAE network. Then, the consistency among the different products was assessed regionally over the Arabian Peninsula and the Sahara Desert. Four distinct independently-derived precipitation products, namely, Global Precipitation Climate Center (GPCC), Willmott-Matsuura 2001 (WM), Tropical Rainfall Measurement Mission (TRMM), and CPC Morphing (CMORPH) were examined. Over the UAE, in situ monthly observations from 6 stations over a time period of 11 years, from 2000 to 2010 inclusive, were used. The correlation with in situ observations, Root Mean Square Error (RMSE), and Relative Bias (rBIAS) were calculated to evaluate the precipitation products. The lowest areal averaged RMSE over all stations, ranging from 3.82mm to 9.98mm, was obtained with the GPCC indicating a higher agreement with in situ observations. The average RMSE of GPCC over the country was 6.18mm. However, the highest areal averaged RMSE, ranging from 9.44 to 19.52mm, was obtained with the WM product with average of 13.57mm. The results showed an overestimation of the observed rainfall values across all products with overall average of 42%. CMORPH product was found to be the most inconsistent products spatially across the UAE with rBIAS ranging from -47% in Al Ain to 372% in Dubai. The correlation with in situ observations was found to be higher with GPCC product ranging from 0.8450 to 0.9494. TRMM was second with an average of 0.8413, ranging from 0.7098 to 0.9248. Furthermore, Mean Relative Difference (MRD) was calculated to investigate the precision among the precipitation products. CMORPH was found to be inconsistent spatially being the lowest estimator for four stations (Adu Dhabi, Al Ain, Sharjah, Ras Al Khaimah) whereas being the highest estimator for the rest two stations (Dubai and Fujairah). Generally, the

  20. GPM Mission Gridded Text Products Providing Surface Precipitation Retrievals

    NASA Astrophysics Data System (ADS)

    Stocker, Erich Franz; Kelley, Owen; Huffman, George; Kummerow, Christian

    2015-04-01

    In February 2015, the Global Precipitation Measurement (GPM) mission core satellite will complete its first year in space. The core satellite carries a conically scanning microwave imager called the GPM Microwave Imager (GMI), which also has 166 GHz and 183 GHz frequency channels. The GPM core satellite also carries a dual frequency radar (DPR) which operates at Ku frequency, similar to the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar), and a new Ka frequency. The precipitation processing system (PPS) is producing swath-based instantaneous precipitation retrievals from GMI, both radars including a dual-frequency product, and a combined GMI/DPR precipitation retrieval. These level 2 products are written in the HDF5 format and have many additional parameters beyond surface precipitation that are organized into appropriate groups. While these retrieval algorithms were developed prior to launch and are not optimal, these algorithms are producing very creditable retrievals. It is appropriate for a wide group of users to have access to the GPM retrievals. However, for reseachers requiring only surface precipitation, these L2 swath products can appear to be very intimidating and they certainly do contain many more variables than the average researcher needs. Some researchers desire only surface retrievals stored in a simple easily accessible format. In response, PPS has begun to produce gridded text based products that contain just the most widely used variables for each instrument (surface rainfall rate, fraction liquid, fraction convective) in a single line for each grid box that contains one or more observations. This paper will describe the gridded data products that are being produced and provide an overview of their content. Currently two types of gridded products are being produced: (1) surface precipitation retrievals from the core satellite instruments - GMI, DPR, and combined GMI/DPR (2) surface precipitation retrievals for the partner

  1. Intercomparison of Global Precipitation Products: The Third Precipitation Intercomparison Project (PIP-3)

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Kidd, Christopher; Petty, Grant; Morrissey, Mark; Goodman, H. Michael; Einaudi, Franco (Technical Monitor)

    2000-01-01

    A set of global, monthly rainfall products has been intercompared to understand the quality and utility of the estimates. The products include 25 observational (satellite-based), four model and two climatological products. The results of the intercomparison indicate a very large range (factor of two or three) of values when all products are considered. The range of values is reduced considerably when the set of observational products is limited to those considered quasi-standard. The model products do significantly poorer in the tropics, but are competitive with satellite-based fields in mid-latitudes over land. Over ocean, products are compared to frequency of precipitation from ship observations. The evaluation of the observational products point to merged data products (including rain gauge information) as providing the overall best results.

  2. Assessment of Satellite Precipitation Products in the Philippine Archipelago

    NASA Astrophysics Data System (ADS)

    Ramos, M. D.; Tendencia, E.; Espana, K.; Sabido, J.; Bagtasa, G.

    2016-06-01

    Precipitation is the most important weather parameter in the Philippines. Made up of more than 7100 islands, the Philippine archipelago is an agricultural country that depends on rain-fed crops. Located in the western rim of the North West Pacific Ocean, this tropical island country is very vulnerable to tropical cyclones that lead to severe flooding events. Recently, satellite-based precipitation estimates have improved significantly and can serve as alternatives to ground-based observations. These data can be used to fill data gaps not only for climatic studies, but can also be utilized for disaster risk reduction and management activities. This study characterized the statistical errors of daily precipitation from four satellite-based rainfall products from (1) the Tropical Rainfall Measuring Mission (TRMM), (2) the CPC Morphing technique (CMORPH) of NOAA and (3) the Global Satellite Mapping of Precipitation (GSMAP) and (4) Precipitation Estimation from Remotely Sensed information using Artificial Neural Networks (PERSIANN). Precipitation data were compared to 52 synoptic weather stations located all over the Philippines. Results show GSMAP to have over all lower bias and CMORPH with lowest Mean Absolute Error (MAE) and Root Mean Square Error (RMSE). In addition, a dichotomous rainfall test reveals GSMAP and CMORPH have low Proportion Correct (PC) for convective and stratiform rainclouds, respectively. TRMM consistently showed high PC for almost all raincloud types. Moreover, all four satellite precipitation showed high Correct Negatives (CN) values for the north-western part of the country during the North-East monsoon and spring monsoonal transition periods.

  3. TRMM .25 deg x .25 deg Gridded Precipitation Text Product

    NASA Technical Reports Server (NTRS)

    Stocker, Erich; Kelley, Owen

    2009-01-01

    Since the launch of the Tropical Rainfall Measuring Mission (TRMM), the Precipitation Measurement Missions science team has endeavored to provide TRMM precipitation retrievals in a variety of formats that are more easily usable by the broad science community than the standard Hierarchical Data Format (HDF) in which TRMM data is produced and archived. At the request of users, the Precipitation Processing System (PPS) has developed a .25 x .25 gridded product in an easily used ASCII text format. The entire TRMM mission data has been made available in this format. The paper provides the details of this new precipitation product that is designated with the TRMM designator 3G68.25. The format is packaged into daily files. It provides hourly precipitation information from the TRMM microwave imager (TMI), precipitation radar (PR), and TMI/PR combined rain retrievals. A major advantage of this approach is the inclusion only of rain data, compression when a particular grid has no rain from the PR or combined, and its direct ASCII text format. For those interested only in rain retrievals and whether rain is convection or stratiform, these products provide a huge reduction in the data volume inherent in the standard TRMM products. This paper provides examples of the 3G68 data products and their uses. It also provides information about C tools that can be used to aggregate daily files into larger time samples. In addition, it describes the possibilities inherent in the spatial sampling which allows resampling into coarser spatial sampling. The paper concludes with information about downloading the gridded text data products.

  4. Online Evaluation of Satellite-derived Global Daily Precipitation Products

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Yu, G.

    2011-12-01

    Precipitation is hard to measure and difficult to 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 expedite the use of satellite precipitation products, the obstacle needs to be removed. We have developed a prototype to address this issue. 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 have increased the temporal coverage and expanded the spatial coverage from the United States to the globe. More products have been added as well. Examples of using the system will be presented. 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 inter-comparing both versions of TRMM products in their areas of interest. Making this service

  5. Extreme precipitation patterns reduced terrestrial ecosystem production across biomass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precipitation regimes are predicted to shift to more extreme patterns that are characterized by more intense rainfall events and longer dry intervals, yet their ecological impacts on vegetation production remain uncertain across biomes in natural climatic conditions. This in situ study investigated ...

  6. Online Assessment of Satellite-Derived Global Precipitation Products

    NASA Technical Reports Server (NTRS)

    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

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

    NASA Astrophysics Data System (ADS)

    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

  8. Few multiyear precipitation-reduction experiments find a shift in the productivity-precipitation relationship.

    PubMed

    Estiarte, Marc; Vicca, Sara; Peñuelas, Josep; Bahn, Michael; Beier, Claus; Emmett, Bridget A; Fay, Philip A; Hanson, Paul J; Hasibeder, Roland; Kigel, Jaime; Kröel-Dulay, Gyorgy; Larsen, Klaus Steenberg; Lellei-Kovács, Eszter; Limousin, Jean-Marc; Ogaya, Romà; Ourcival, Jean-Marc; Reinsch, Sabine; Sala, Osvaldo E; Schmidt, Inger Kappel; Sternberg, Marcelo; Tielbörger, Katja; Tietema, Albert; Janssens, Ivan A

    2016-07-01

    Well-defined productivity-precipitation relationships of ecosystems are needed as benchmarks for the validation of land models used for future projections. The productivity-precipitation relationship may be studied in two ways: the spatial approach relates differences in productivity to those in precipitation among sites along a precipitation gradient (the spatial fit, with a steeper slope); the temporal approach relates interannual productivity changes to variation in precipitation within sites (the temporal fits, with flatter slopes). Precipitation-reduction experiments in natural ecosystems represent a complement to the fits, because they can reduce precipitation below the natural range and are thus well suited to study potential effects of climate drying. Here, we analyse the effects of dry treatments in eleven multiyear precipitation-manipulation experiments, focusing on changes in the temporal fit. We expected that structural changes in the dry treatments would occur in some experiments, thereby reducing the intercept of the temporal fit and displacing the productivity-precipitation relationship downward the spatial fit. The majority of experiments (72%) showed that dry treatments did not alter the temporal fit. This implies that current temporal fits are to be preferred over the spatial fit to benchmark land-model projections of productivity under future climate within the precipitation ranges covered by the experiments. Moreover, in two experiments, the intercept of the temporal fit unexpectedly increased due to mechanisms that reduced either water loss or nutrient loss. The expected decrease of the intercept was observed in only one experiment, and only when distinguishing between the late and the early phases of the experiment. This implies that we currently do not know at which precipitation-reduction level or at which experimental duration structural changes will start to alter ecosystem productivity. Our study highlights the need for experiments with

  9. Physically-based, Hydrologic Simulations Driven by Three Precipitation Products

    NASA Astrophysics Data System (ADS)

    Chintalapudi, S.; Sharif, H. O.; Yeggina, S.; El Hassan, A.

    2011-12-01

    This study evaluates the model-simulated stream discharge over the Guadalupe River basin in central Texas driven by three precipitation products: the Guadalupe-Blanco River Authority (GBRA) rain gauge network, the Next Generation Weather Radar (NEXRAD) Stage ΙΙΙ precipitation product, and the Tropical Rainfall Measurement Mission (TRMM) 3B42 product. Focus will be on results from the Upper Guadalupe River sub-basin. This sub-basin is more prone to flooding due to its geological properties (thin soils, exposed bedrock, and sparse vegetation) and the impact of Balcones Escarpment on the moisture coming from the Gulf of Mexico. The physically based, distributed-parameter Gridded Surface Subsurface Hydrologic Analysis (GSSHA) hydrologic model was used to simulate the June-2002 flooding event. Simulations driven by NEXRAD Stage ΙΙΙ 15 - min precipitation yielded better results with low RMSE (88.3%), high NSE (0.6), high R2 (0.73), low RSR (0.63) and low PBIAS (-17.3%) compared to simulations driven by the other products.

  10. Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity.

    PubMed

    Gherardi, Laureano A; Sala, Osvaldo E

    2015-12-01

    Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional diversity and its consequences for ecosystem functioning are assessed here using a 6-year rainfall manipulation experiment. Five precipitation treatments were switched annually resulting in increased levels of precipitation variability while maintaining average precipitation constant. Functional diversity showed a positive response to increased variability due to increased evenness. Dominant grasses decreased and rare plant functional types increased in abundance because grasses showed a hump-shaped response to precipitation with a maximum around modal precipitation, whereas rare species peaked at high precipitation values. Increased functional diversity ameliorated negative effects of precipitation variability on primary production. Rare species buffered the effect of precipitation variability on the variability in total productivity because their variance decreases with increasing precipitation variance. PMID:26437913

  11. Improving high-resolution quantitative precipitation estimation via fusion of multiple radar-based precipitation products

    NASA Astrophysics Data System (ADS)

    Rafieeinasab, Arezoo; Norouzi, Amir; Seo, Dong-Jun; Nelson, Brian

    2015-12-01

    For monitoring and prediction of water-related hazards in urban areas such as flash flooding, high-resolution hydrologic and hydraulic modeling is necessary. Because of large sensitivity and scale dependence of rainfall-runoff models to errors in quantitative precipitation estimates (QPE), it is very important that the accuracy of QPE be improved in high-resolution hydrologic modeling to the greatest extent possible. With the availability of multiple radar-based precipitation products in many areas, one may now consider fusing them to produce more accurate high-resolution QPE for a wide spectrum of applications. In this work, we formulate and comparatively evaluate four relatively simple procedures for such fusion based on Fisher estimation and its conditional bias-penalized variant: Direct Estimation (DE), Bias Correction (BC), Reduced-Dimension Bias Correction (RBC) and Simple Estimation (SE). They are applied to fuse the Multisensor Precipitation Estimator (MPE) and radar-only Next Generation QPE (Q2) products at the 15-min 1-km resolution (Experiment 1), and the MPE and Collaborative Adaptive Sensing of the Atmosphere (CASA) QPE products at the 15-min 500-m resolution (Experiment 2). The resulting fused estimates are evaluated using the 15-min rain gauge observations from the City of Grand Prairie in the Dallas-Fort Worth Metroplex (DFW) in north Texas. The main criterion used for evaluation is that the fused QPE improves over the ingredient QPEs at their native spatial resolutions, and that, at the higher resolution, the fused QPE improves not only over the ingredient higher-resolution QPE but also over the ingredient lower-resolution QPE trivially disaggregated using the ingredient high-resolution QPE. All four procedures assume that the ingredient QPEs are unbiased, which is not likely to hold true in reality even if real-time bias correction is in operation. To test robustness under more realistic conditions, the fusion procedures were evaluated with and

  12. Effects of alteration product precipitation on glass dissolution

    SciTech Connect

    Strachan, Denis M.; Neeway, James J.

    2014-06-01

    Understanding the mechanisms that control the durability of nuclear waste glass is paramount if reliable models are to be constructed so that the glass dissolution rate in a given geological repository can be calculated. Presently, it is agreed that (boro)silicate glasses dissolve in water at a rate dependent on the solution concentration of orthosilicic acid (H4SiO4) with higher [H4SiO4] leading to lower dissolution rates. Once the reaction has slowed as a result of the buildup of H4SiO4, another increase in the rate has been observed that corresponds to the precipitation of certain silica-bearing alteration products. However, it has also been observed that the concentration of silica-bearing solution species does not significantly decrease, indicating saturation, while other glass tracer elements concentrations continue to increase, indicating that the glass is still dissolving. In this study, we have used the Geochemist’s Workbench code to investigate the relationship between glass dissolution rates and the precipitation rate of a representative zeolitic silica-bearing alteration product, analcime [Na(AlSi2O6)∙H2O]. To simplify the calculations, we suppressed all alteration products except analcime, gibbsite (Al(OH)3), and amorphous silica. The pseudo-equilibrium-constant matrix for amorphous silica was substituted for the glass pseudo-equilibrium-constant matrix because it has been shown that silicate glasses act as a silica-only solid with respect to kinetic considerations. In this article, we present the results of our calculations of the glass dissolution rate at different values for the analcime precipitation rate constant and the effects of varying the glass dissolution rate constant at a constant analcime precipitation rate constant. From the simulations we conclude, firstly, that the rate of glass dissolution is dependent on the kinetics of

  13. Enhanced precipitation variability decreases grass- and increases shrub-productivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present resul...

  14. PURIFICATION OF PLUTONIUM USING A CERIUM PRECIPITATE AS A CARRIER FOR FISSION PRODUCTS

    DOEpatents

    Faris, B.F.; Olson, C.M.

    1961-07-01

    Bismuth phosphate carrier precipitation processes are described for the separation of plutonium from fission products wherein in at least one step bismuth phosphate is precipitated in the presence of hexavalent plutonium thereby carrying a portion of the fission products from soluble plu tonium values. In this step, a cerium phosphate precipitate is formed in conjunction with the bismuth phosphate precipitate, thereby increasing the amount of fission products removed from solution.

  15. Few multi-year precipitation-reduction experiments find a shift in the productivity-precipitation relationship

    DOE PAGESBeta

    Estiarte, Marc; Vicca, Sara; Penuelas, Josep; Bahn, Michael; Beier, Claus; Emmett, Bridget; Fay, Phillip A.; Hanson, Paul J.; Hasibeder, Roland; Kigel, Jaime; et al

    2016-04-06

    Well-defined productivity–precipitation relationships of ecosystems are needed as benchmarks for the validation of land models used for future projections. The productivity–precipitation relationship may be studied in two ways: the spatial approach relates differences in productivity to those in precipitation among sites along a precipitation gradient (the spatial fit, with a steeper slope); the temporal approach relates interannual productivity changes to variation in precipitation within sites (the temporal fits, with flatter slopes). Precipitation–reduction experiments in natural ecosystems represent a complement to the fits, because they can reduce precipitation below the natural range and are thus well suited to study potential effectsmore » of climate drying. Here, we analyse the effects of dry treatments in eleven multiyear precipitation–manipulation experiments, focusing on changes in the temporal fit. We expected that structural changes in the dry treatments would occur in some experiments, thereby reducing the intercept of the temporal fit and displacing the productivity–precipitation relationship downward the spatial fit. Seventy two percent of expiriments showed that dry treatments did not alter the temporal fit. This implies that current temporal fits are to be preferred over the spatial fit to benchmark land-model projections of productivity under future climate within the precipitation ranges covered by the experiments. Moreover, in two experiments, the intercept of the temporal fit unexpectedly increased due to mechanisms that reduced either water loss or nutrient loss. The expected decrease of the intercept was observed in only one experiment, and only when distinguishing between the late and the early phases of the experiment. This implies that we currently do not know at which precipitation–reduction level or at which experimental duration structural changes will start to alter ecosystem productivity. Our study highlights the need

  16. Evaluation of global fine-resolution precipitation products and their uncertainty quantification in ensemble discharge simulations

    NASA Astrophysics Data System (ADS)

    Qi, W.; Zhang, C.; Fu, G. T.; Sweetapple, C.; Zhou, H. C.

    2015-09-01

    The applicability of six fine-resolution precipitation products, including precipitation radar, infrared, microwave and gauge-based products using different precipitation computation recipes, is comprehensively evaluated using statistical and hydrological methods in a usually-neglected area (northeastern China), and a framework quantifying uncertainty contributions of precipitation products, hydrological models and their interactions to uncertainties in ensemble discharges is proposed. The investigated precipitation products include TRMM3B42, TRMM3B42RT, GLDAS/Noah, APHRODITE, PERSIANN and GSMAP-MVK+. Two hydrological models of different complexities, i.e., a water and energy budget-based distributed hydrological model and a physically-based semi-distributed hydrological model, are employed to investigate the influence of hydrological models on simulated discharges. Results show APHRODITE has high accuracy at a monthly scale compared with other products, and the cloud motion vectors used by GSMAP-MVK+ show huge advantage. These findings could be very useful for validation, refinement and future development of satellite-based products (e.g., NASA Global Precipitation Measurement). Although significant uncertainty exists in heavy precipitation, hydrological models contribute most of the uncertainty in extreme discharges. Interactions between precipitation products and hydrological models contribute significantly to uncertainty in discharge simulations and a better precipitation product does not guarantee a better discharge simulation because of interactions. It is also found that a good discharge simulation depends on a good coalition of a hydrological model and a precipitation product, suggesting that, although the satellite-based precipitation products are not as accurate as the gauge-based product, they could have better performance in discharge simulations when appropriately combined with hydrological models. This information is revealed for the first time and

  17. Evaluation of global fine-resolution precipitation products and their uncertainty quantification in ensemble discharge simulations

    NASA Astrophysics Data System (ADS)

    Qi, W.; Zhang, C.; Fu, G.; Sweetapple, C.; Zhou, H.

    2016-02-01

    The applicability of six fine-resolution precipitation products, including precipitation radar, infrared, microwave and gauge-based products, using different precipitation computation recipes, is evaluated using statistical and hydrological methods in northeastern China. In addition, a framework quantifying uncertainty contributions of precipitation products, hydrological models, and their interactions to uncertainties in ensemble discharges is proposed. The investigated precipitation products are Tropical Rainfall Measuring Mission (TRMM) products (TRMM3B42 and TRMM3B42RT), Global Land Data Assimilation System (GLDAS)/Noah, Asian Precipitation - Highly-Resolved Observational Data Integration Towards Evaluation of Water Resources (APHRODITE), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN), and a Global Satellite Mapping of Precipitation (GSMAP-MVK+) product. Two hydrological models of different complexities, i.e. a water and energy budget-based distributed hydrological model and a physically based semi-distributed hydrological model, are employed to investigate the influence of hydrological models on simulated discharges. Results show APHRODITE has high accuracy at a monthly scale compared with other products, and GSMAP-MVK+ shows huge advantage and is better than TRMM3B42 in relative bias (RB), Nash-Sutcliffe coefficient of efficiency (NSE), root mean square error (RMSE), correlation coefficient (CC), false alarm ratio, and critical success index. These findings could be very useful for validation, refinement, and future development of satellite-based products (e.g. NASA Global Precipitation Measurement). Although large uncertainty exists in heavy precipitation, hydrological models contribute most of the uncertainty in extreme discharges. Interactions between precipitation products and hydrological models can have the similar magnitude of contribution to discharge uncertainty as the hydrological models. A

  18. An Error Model for High-Time Resolution Satellite Precipitation Products

    NASA Astrophysics Data System (ADS)

    Maggioni, V.; Sapiano, M.; Adler, R. F.; Huffman, G. J.; Tian, Y.

    2013-12-01

    A new error scheme (PUSH: Precipitation Uncertainties for Satellite Hydrology) is presented to provide global estimates of errors for high time resolution, merged precipitation products. Errors are estimated for the widely used Tropical Rainfall Monitoring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) 3B42 product at daily/0.25° resolution, using the high quality NOAA CPC-UNI gauge analysis as the benchmark. Each of the following four scenarios is explored and explicitly modeled: correct no-precipitation detection (both satellite and gauges detect no precipitation), missed precipitation (satellite records a zero, but it is incorrect), false alarm (satellite detects precipitation, but the reference is zero), and hit (both satellite and gauges detect precipitation). Results over Oklahoma show that the estimated probability distributions are able to reproduce the probability density functions of the benchmark precipitation, in terms of both expected values and quantiles. PUSH adequately captures missed precipitation and false detection uncertainties, reproduces the spatial pattern of the error, and shows a good agreement between observed and estimated errors. The resulting error estimates could be attached to the standard products for the scientific community to use. Investigation is underway to: 1) test the approach in different regions of the world; 2) verify the ability of the model to discern the systematic and random components of the error; 3) and evaluate the model performance when higher time-resolution satellite products (i.e., 3-hourly) are employed.

  19. Spatial Downscaling of TRMM Precipitation using MODIS product in the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Cho, H.; Choi, M.

    2013-12-01

    Precipitation is a major driving force in the water cycle. But, it is difficult to provide spatially distributed precipitation data from isolated individual in situ. The Tropical Rainfall Monitoring Mission (TRMM) satellite can provide precipitation data with relatively coarse spatial resolution (0.25° scale) at daily basis. In order to overcome the coarse spatial resolution of TRMM precipitation products, we conducted a downscaling technique using a scaling parameter from the Moderate Resolution Imaging Spectroradiometers (MODIS) sensor. In this study, statistical relations between precipitation estimates derived from the TRMM satellite and the normalized difference vegetation index (NDVI) which is obtained from the MODIS sensor in TERRA satellite are found for different spatial scales on the Korean peninsula in northeast Asia. We obtain the downscaled precipitation mapping by regression equation between yearly TRMM precipitations values and annual average NDVI aggregating 1km to 25 degree. The downscaled precipitation is validated using time series of the ground measurements precipitation dataset provided by Korea Meteorological Organization (KMO) from 2002 to 2005. To improve the spatial downscaling of precipitation, we will conduct a study about correlation between precipitation and land surface temperature, perceptible water and other hydrological parameters.

  20. SEPARATION OF FISSION PRODUCT VALUES FROM THE HEXAVALENT PLUTONIUM BY CARRIER PRECIPITATION

    DOEpatents

    Davies, T.H.

    1959-12-15

    An improved precipitation of fission products on bismuth phosphate from an aqueous mineral acid solution also containing hexavalent plutonium by incorporating, prior to bismuth phosphate precipitation, from 0.05 to 2.5 grams/ liter of zirconium phosphate, niobium oxide. and/or lanthanum fluoride is described. The plutonium remains in solution.

  1. G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) Value-Added Product

    SciTech Connect

    Koontz, A; Cadeddu, M

    2012-12-05

    The G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) value-added product (VAP) computes precipitable water vapor using neural network techniques from data measured by the GVR. The GVR reports time-series measurements of brightness temperatures for four channels located at 183.3 ± 1, 3, 7, and 14 GHz.

  2. Online tools for uncovering data quality issues in satellite-based global precipitation products

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Heo, G.

    2015-12-01

    Accurate and timely available global precipitation products are important to many applications such as flood forecasting, hydrological modeling, vector-borne disease research, crop yield estimates, etc. However, data quality issues such as biases and uncertainties are common in satellite-based precipitation products and it is important to understand these issues in applications. In recent years, algorithms using multi-satellites and multi-sensors for satellite-based precipitation estimates have become popular, such as the TRMM (Tropical Rainfall Measuring Mission) Multi-satellite Precipitation Analysis (TMPA) and the latest Integrated Multi-satellitE Retrievals for GPM (IMERG). Studies show that data quality issues for multi-satellite and multi-sensor products can vary with space and time and can be difficult to summarize. Online tools can provide customized results for a given area of interest, allowing customized investigation or comparison on several precipitation products. Because downloading data and software is not required, online tools can facilitate precipitation product evaluation and comparison. In this presentation, we will present online tools to uncover data quality issues in satellite-based global precipitation products. Examples will be presented as well.

  3. Explore GPM IMERG and Other Global Precipitation Products with GES DISC GIOVANNI

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Ostrenga, D.; Vollmer, B.; Macritchie, K.; Kempler, S. J.

    2015-12-01

    New features and capabilities in the newly released GIOVANNI allow exploring GPM IMERG (Integrated Multi-satelliE Retrievals for GPM) Early, Late and Final Run global half-hourly and monthly precipitation products as well as other precipitation products distributed by the GES DISC such as TRMM Multi-Satellite Precipitation Analysis (TMPA), MERRA (Modern Era Retrospective-Analysis for Research and Applications), NLDAS (North American Land Data Assimilation Systems), GLDAS (Global Land Data Assimilation Systems), etc. GIOVANNI is a web-based tool developed by the GES DISC (Goddard Earth Sciences and Data Information Services Center), to visualize and analyze Earth science data without having to download data and software. The new interface in GIOVANNI allows searching and filtering precipitation products from different NASA missions and projects and expands the capabilities to inter-compare different precipitation products in one interface. Knowing differences in precipitation products is important to identify issues in retrieval algorithms, biases, uncertainties, etc. Due to different formats, data structures, units and so on, it is not easy to inter-compare these precipitation products. The recently added new features and capabilities (unit conversion, regridding, etc.) in GIOVANNI make inter-comparison possible. In this presentation, we will describe these new feature and capabilities along with examples. (Related URLs: GIOVANNI URL: http://giovanni.gsfc.nasa.gov/giovanni/; GES DISC: http://disc.gsfc.nasa.gov/)

  4. Explore GPM IMERG and Other Global Precipitation Products with GES DISC GIOVANNI

    NASA Technical Reports Server (NTRS)

    Liu, Zhong; Ostrenga, Dana M.; Vollmer, Bruce; MacRitchie, Kyle; Kempler, Steven

    2015-01-01

    New features and capabilities in the newly released GIOVANNI allow exploring GPM IMERG (Integrated Multi-satelliE Retrievals for GPM) Early, Late and Final Run global half-hourly and monthly precipitation products as well as other precipitation products distributed by the GES DISC such as TRMM Multi-Satellite Precipitation Analysis (TMPA), MERRA (Modern Era Retrospective-Analysis for Research and Applications), NLDAS (North American Land Data Assimilation Systems), GLDAS (Global Land Data Assimilation Systems), etc. GIOVANNI is a web-based tool developed by the GES DISC (Goddard Earth Sciences and Data Information Services Center) to visualize and analyze Earth science data without having to download data and software. The new interface in GIOVANNI allows searching and filtering precipitation products from different NASA missions and projects and expands the capabilities to inter-compare different precipitation products in one interface. Knowing differences in precipitation products is important to identify issues in retrieval algorithms, biases, uncertainties, etc. Due to different formats, data structures, units and so on, it is not easy to inter-compare precipitation products. Newly added features and capabilities (unit conversion, regridding, etc.) in GIOVANNI make inter-comparisons possible. In this presentation, we will describe these new features and capabilities along with examples.

  5. ARSENATE CARRIER PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM NEUTRON IRRADIATED URANIUM AND RADIOACTIVE FISSION PRODUCTS

    DOEpatents

    Thompson, S.G.; Miller, D.R.; James, R.A.

    1961-06-20

    A process is described for precipitating Pu from an aqueous solution as the arsenate, either per se or on a bismuth arsenate carrier, whereby a separation from uranium and fission products, if present in solution, is accomplished.

  6. PROCESS USING BISMUTH PHOSPHATE AS A CARRIER PRECIPITATE FOR FISSION PRODUCTS AND PLUTONIUM VALUES

    DOEpatents

    Finzel, T.G.

    1959-03-10

    A process is described for separating plutonium from fission products carried therewith when plutonium in the reduced oxidation state is removed from a nitric acid solution of irradiated uranium by means of bismuth phosphate as a carrier precipitate. The bismuth phosphate carrier precipitate is dissolved by treatment with nitric acid and the plutonium therein is oxidized to the hexavalent oxidation state by means of potassium dichromate. Separation of the plutonium from the fission products is accomplished by again precipitating bismuth phosphate and removing the precipitate which now carries the fission products and a small percentage of the plutonium present. The amount of plutonium carried in this last step may be minimized by addition of sodium fluoride, so as to make the solution 0.03N in NaF, prior to the oxidation and prccipitation step.

  7. Assessment of Remotely-Sensed precipitation products across the Saudi Arabia Region

    NASA Astrophysics Data System (ADS)

    Kheimi, M.

    2012-12-01

    Water resources controlling, predicting, and decision making require a high resolution and reliable estimates of precipitation. Precipitation events significantly important and have a huge impact on the economy, the environment, and the society, especially in the largely arid countries. Recently, with the leap of developing satellite-retrieved precipitation products with high special resolution and global coverage that resulted in new source of sustainable precipitation estimates. However, the incorporation between satellite- retrieved estimates and the operational decision making are not well recognized due to lack of information towards uncertainties and consistency. In this study, the primary goal was to evaluate the performance of satellite products rainfall estimator (TRMM-3B42) and (PERSSIAN)around Saudi Arabia, by analyzing the TRMM-3B42 product for the period of January 2000- October 2010 and the PERSSIAN product for the period of March 2000 until December 2007. Independent rain gauge data were collected from over 29 local precipitation gauge stations from all thirteen provinces located in Saudi Arabia. After aggregation and interpolation, this data was specifically used to diagnose systematic differences between in-situ based rainfall and satellite derived rainfall using an extensive selection of validation metrics. The results show according to the probability of detecting rainfall amounts and volume of correctly identified precipitation, TRMM data sets led to better estimates and high correlation than PERSIANN product. Whereas in the false alarms ratio is higher in TRMM than in PERSSIAN. In fact, all precipitation products tend to miss a significant amount of rainfall. From the analysis, a recommendation suggested to extend the efforts towards necessary development of algorithms that capture precipitation with more consistency.

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

    NASA Technical Reports Server (NTRS)

    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

  9. Evolving Capabilities and Expectations for the GPCP Precipitation Products

    NASA Astrophysics Data System (ADS)

    Huffman, G. J.; Adler, R. F.; Bolvin, D. T.; Nelkin, E. J.

    2014-12-01

    The Global Precipitation Climatology Project (GPCP) was established in the mid-1990's to determine whether the then-new passive microwave sensors could reliably depict quasi-global variations in precipitation, in particular those associated with El Niño Southern Oscillation (ENSO) events. This international community-based effort was successful, and its data record now extends past 35 years. In the process, we have found ways to use estimates from sensors flying before the passive microwave era, and estimates for polar regions in which the passive microwave retrievals are not useful, as well as providing pentad (5-day) and daily estimates (the latter for a subset of the 1979-present record). Several versions have been released as lessons learned and new input datasets have been applied to the computation. Among these lessons are the importance of maintaining consistency in input data sources, requiring consistent processing for the entire record of input datasets, and ensuring completeness in data coverage. The resulting data sets were not originally designed to be formal Climate Data Records (CDRs), but they do emphasize homogeneity, high quality, and stability in the input data sets. The success of the datasets has raised user expectations and encouraged a variety of analyses that were not envisioned in the original design. In particular, the GPCP data contain approximations that make it difficult for the data to adequately represent fine-scale "extremes". As well, improved input data sets and algorithms have been developed which are not accommodated in the current version. In response, the GPCP is working under NASA MEaSUREs funding to create a next-generation version at finer scale that is better suited for a wider range of analyses. The widening circle of non-expert users has widened the range of formats and services that are needed. These developments increase the utility of such data sets to users, with the unintended effect that the cost of getting a data

  10. Supporting Hydrometeorological Research and Applications with Global Precipitation Measurement (GPM) Products and Services

    NASA Technical Reports Server (NTRS)

    Liu, Zhong; Ostrenga, D.; Vollmer, B.; Deshong, B.; MacRitchie, K.; Greene, M.; Kempler, S.

    2016-01-01

    Precipitation is an important dataset in hydrometeorological research and applications such as flood modeling, drought monitoring, etc. On February 27, 2014, the NASA Global Precipitation Measurement (GPM) mission was launched to provide the next-generation global observations of rain and snow (http:pmm.nasa.govGPM). The GPM mission consists of an international network of satellites in which a GPM Core Observatory satellite carries both active and passive microwave instruments to measure precipitation and serve as a reference standard, to unify precipitation measurements from a constellation of other research and operational satellites. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data. The GES DISC is home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). GPM products currently available include the following:1. Level-1 GPM Microwave Imager (GMI) and partner radiometer products2. Goddard Profiling Algorithm (GPROF) GMI and partner products (Level-2 and Level-3)3. GPM dual-frequency precipitation radar and their combined products (Level-2 and Level-3)4. Integrated Multi-satellitE Retrievals for GPM (IMERG) products (early, late, and final run)GPM data can be accessed through a number of data services (e.g., Simple Subset Wizard, OPeNDAP, WMS, WCS, ftp, etc.). A newly released Unified User Interface or UUI is a single interface to provide users seamless access to data, information and services. For example, a search for precipitation products will not only return TRMM and GPM products, but also other global precipitation products such as MERRA (Modern Era Retrospective-Analysis for Research and Applications), GLDAS (Global Land Data Assimilation Systems), etc.New features and capabilities have been recently added in GIOVANNI to allow exploring and inter-comparing GPM IMERG (Integrated Multi-satelliE Retrievals for GPM) half-hourly and monthly precipitation

  11. Comparison of Remotely Sensed Precipitation and Evapotranspiration Products for a Statewide Water Assessment of New Mexico

    NASA Astrophysics Data System (ADS)

    Schmugge, T. J.; Fernald, A.; Peterson, K.; Walker, S.; Hewitt, I. C.; Hendrickx, J. M. H.

    2014-12-01

    Precipitation and evapotranspiration (ET) are the major components of the water balance in New Mexico. Therefore, it is critical to acquire accurate precipitation and ET data as input into a statewide water balance. Since existing meteorological stations in New Mexico don't cover the entire state and leave many areas without accurate information, we propose to evaluate the accuracy of existing nationwide remotely sensed databases for precipitation and ET to quantify the spatial and temporal distributions of those components in a statewide water balance. In this study we compare five precipitation products and three ET products: the CHIRPS (Climate Hazard Group InfraRed Precipitation with Station data) model, the National Weather Service Advanced Hydrologic Prediction Service product, the PERSIANN-GCCS (Precipitation Estimation from Remote Sensed Information using Artificial Neural Network - Global Cloud Classification System) model, the PRISM (Parameter-elevation Relationships on Independent Slopes) model the TRMM (Tropical Rainfall Measuring Mission, the ALExI (Atmosphere-Land Exchange Inverse) model, the MOD 16 ( MODIS Global Evapotranspiration Product) model of NASA, and the SSEB (Simplified Surface Energy Balance) model produced by the USGS. Early results show a strong relationship between all precipitation products across the state of New Mexico from 2000 to 2013 with an average depth of 315 mm, except for the PERSIANN model which has a rainfall depth approximately 53% higher (673mm) than the average of the other models. Additionally there is a strong relationship between the ALExI and SSEB ET models yet these models exceed the precipitation in the state by approximately 35%. The MOD 16 ET model has an average ET depth approximately 42% less than the average of the precipitation models and about 60% less than the ALExI and SSEB ET models. Future work includes validation of precipitation and ET models using high density rain gauge networks, as well as METRIC

  12. MODIS EVI as a Proxy for Net Primary Production across Precipitation Regimes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Above ground net primary production (ANPP) is a measure of the rate of photosynthesis in an ecosystem, and is indicative of its biomass productivity. Prior studies have reported a relationship between ANPP and annual precipitation which converged across biomes in dry years. This deserves further s...

  13. Seasonal temperature and precipitation effects on cow-calf production in northern mixed-grass prairie

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying the effects of seasonal temperature and precipitation on cow-calf production on rangelands is challenging, as few long-term (>20 yr) studies have been reported. However, an understanding of how seasonal weather inconsistency affects beef production is needed for beef producers to better ...

  14. Improving Flood Modeling Applications of Global Reanalysis Precipitation Products through Satellite-driven Downscaling

    NASA Astrophysics Data System (ADS)

    Anagnostou, E. N.; Seyyedi, H.; Beighley, E., II; McCollum, J.

    2014-12-01

    Deriving flood vulnerability maps at basin scale typically requires simulating a long record of annual maximum discharges. To improve this approach, long precipitation records from global reanalysis systems must be downscaled to a spatio-temporal resolution applicable for flood modeling. This study evaluates a combined spatial downscaling and error correction technique based on high-resolution satellite precipitation products applied on NASA's Global Land Data Assimilation System (GLDAS) reanalysis precipitation dataset. The TRMM 3B42 25-km and 3-hourly blended satellite precipitation product is used for driving the GLDAS reanalysis downscaling. The study focuses on 437 flood-inducing storm events that occurred over a period of ten years (2002-2011) in the Susquehanna River basin located in the northeast United States. A validation strategy was devised for assessing error metrics in rainfall and simulated runoff as function of basin area, storm severity and season. The WSR-88D gauge-adjusted radar-rainfall (stage IV) product was used as the reference rainfall dataset, while runoff simulations forced with the stage IV precipitation dataset were considered as the runoff reference. Results show that the generated rainfall ensembles from the downscaled reanalysis products encapsulate the reference rainfall. Frequency analysis of rainfall and runoff and mean relative error and root mean square error statistics exhibited improvements in the precipitation and runoff simulation error statistics of the 3B42-driven downscaled GLDAS reanalysis dataset compared to the original reanalysis precipitation product. Results vary by season and less by basin scale. The proposed downscaling scheme is modular in design and can be applied on different satellite and reanalysis dataset over different regions.

  15. Analyses of Chinese Hourly Precipitation Using Gauge Observations and Satellite Estimates Products

    NASA Astrophysics Data System (ADS)

    Pan, Y.; Yu, J.; Shen, Y.

    2010-12-01

    Highly spatial-temporal and accurate precipitation analyses are essential for monitoring the catastrophic mesoscale weather systems, examining numerical model outputs, and doing dynamic researches on mesoscale meteorology. In recent years, Chinese government has gradually developed a ground-based observational net of 30000 auto-weather-stations (AWS) all over the country, most of which are in the eastern and southern China. The real-time data of gauged rainfall is transported to National Meteorological Information of China (NMIC) every hour, and its quality has been strictly and effectually controlled. Taking advantage of these resources, an hourly Chinese Precipitation Analyses Products (CPAP) with fine resolution is developed. But on the Tibetan Plateau where the AWS is still sparse, the accuracy of precipitation can not satisfy the operational needs yet. Otherwise, CMORPH has a well performance on the space structure of rainfall over China in warm season, but loses on intensity. Thus, we make a merge test analysis at resolution of 0.1 ×0.1 degree , using Optimum Interpolation (OI) to combine hourly CPAP with CMORPH estimates precipitation products. Before OI,the systematic bias in CMORPH have been partly corrected by gauge data through PDF adjustments. The validation of the merge test from June to August 2009 shows that, the combined products can obviously reduce the bias to the gauge analyses CPAP, and also have highly coefficient with it. It is more important that, the combined products provide a reasonable and full-covered precipitation structure over Tibetan Plateau.

  16. Productivity responses of desert vegetation to precipitation patterns across a rainfall gradient.

    PubMed

    Li, Fang; Zhao, Wenzhi; Liu, Hu

    2015-03-01

    The influences of previous-year precipitation and episodic rainfall events on dryland plants and communities are poorly quantified in the temperate desert region of Northwest China. To evaluate the thresholds and lags in the response of aboveground net primary productivity (ANPP) to variability in rainfall pulses and seasonal precipitation along the precipitation-productivity gradient in three desert ecosystems with different precipitation regimes, we collected precipitation data from 2000 to 2012 in Shandan (SD), Linze (LZ) and Jiuquan (JQ) in northwestern China. Further, we extracted the corresponding MODIS Normalized Difference Vegetation Index (NDVI, a proxy for ANPP) datasets at 250 m spatial resolution. We then evaluated different desert ecosystems responses using statistical analysis, and a threshold-delay model (TDM). TDM is an integrative framework for analysis of plant growth, precipitation thresholds, and plant functional type strategies that capture the nonlinear nature of plant responses to rainfall pulses. Our results showed that: (1) the growing season NDVIINT (INT stands for time-integrated) was largely correlated with the warm season (spring/summer) at our mildly-arid desert ecosystem (SD). The arid ecosystem (LZ) exhibited a different response, and the growing season NDVIINT depended highly on the previous year's fall/winter precipitation and ANPP. At the extremely arid site (JQ), the variability of growing season NDVIINT was equally correlated with the cool- and warm-season precipitation; (2) some parameters of threshold-delay differed among the three sites: while the response of NDVI to rainfall pulses began at about 5 mm for all the sites, the maximum thresholds in SD, LZ, and JQ were about 55, 35 and 30 mm respectively, increasing with an increase in mean annual precipitation. By and large, more previous year's fall/winter precipitation, and large rainfall events, significantly enhanced the growth of desert vegetation, and desert ecosystems

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

    NASA Astrophysics Data System (ADS)

    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. Legacies of precipitation fluctuations on primary production: theory and data synthesis

    PubMed Central

    Sala, Osvaldo E.; Gherardi, Laureano A.; Reichmann, Lara; Jobbágy, Esteban; Peters, Debra

    2012-01-01

    Variability of above-ground net primary production (ANPP) of arid to sub-humid ecosystems displays a closer association with precipitation when considered across space (based on multiyear averages for different locations) than through time (based on year-to-year change at single locations). Here, we propose a theory of controls of ANPP based on four hypotheses about legacies of wet and dry years that explains space versus time differences in ANPP–precipitation relationships. We tested the hypotheses using 16 long-term series of ANPP. We found that legacies revealed by the association of current- versus previous-year conditions through the temporal series occur across all ecosystem types from deserts to mesic grasslands. Therefore, previous-year precipitation and ANPP control a significant fraction of current-year production. We developed unified models for the controls of ANPP through space and time. The relative importance of current-versus previous-year precipitation changes along a gradient of mean annual precipitation with the importance of current-year PPT decreasing, whereas the importance of previous-year PPT remains constant as mean annual precipitation increases. Finally, our results suggest that ANPP will respond to climate-change-driven alterations in water availability and, more importantly, that the magnitude of the response will increase with time. PMID:23045711

  19. Satellite-driven downscaling of global reanalysis precipitation products for hydrological applications

    NASA Astrophysics Data System (ADS)

    Seyyedi, H.; Anagnostou, E. N.; Beighley, E.; McCollum, J.

    2014-12-01

    Deriving flood hazard maps for ungauged basins typically requires simulating a long record of annual maximum discharges. To improve this approach, precipitation from global reanalysis systems must be downscaled to a spatial and temporal resolution applicable for flood modeling. This study evaluates such downscaling and error correction approaches for improving hydrologic applications using a combination of NASA's Global Land Data Assimilation System (GLDAS) precipitation data set and a higher resolution multi-satellite precipitation product (TRMM). The study focuses on 437 flood-inducing storm events that occurred over a period of ten years (2002-2011) in the Susquehanna River basin located in the northeastern United States. A validation strategy was devised for assessing error metrics in rainfall and simulated runoff as function of basin area, storm severity, and season. The WSR-88D gauge-adjusted radar-rainfall (stage IV) product was used as the reference rainfall data set, while runoff simulations forced with the stage IV precipitation data set were considered as the runoff reference. Results show that the generated rainfall ensembles from the downscaled reanalysis product encapsulate the reference rainfall. The statistical analysis consists of frequency and quantile plots plus mean relative error and root-mean-square error statistics. The results demonstrated improvements in the precipitation and runoff simulation error statistics of the satellite-driven downscaled reanalysis data set compared to the original reanalysis precipitation product. Results vary by season and less by basin scale. In the fall season specifically, the downscaled product has 3 times lower mean relative error than the original product; this ratio increases to 4 times for the simulated runoff values. The proposed downscaling scheme is modular in design and can be applied on any gridded satellite and reanalysis data set.

  20. Satellite-driven downscaling of global reanalysis precipitation products for hydrological applications

    NASA Astrophysics Data System (ADS)

    Seyyedi, H.; Anagnostou, E. N.; Beighley, E.; McCollum, J.

    2014-07-01

    Deriving flood hazard maps for ungauged basins typically requires simulating a long record of annual maximum discharges. To improve this approach, precipitation from global reanalysis systems must be downscaled to a spatial and temporal resolution applicable for flood modeling. This study evaluates such downscaling and error correction approaches for improving hydrologic applications using a combination of NASA's Global Land Data Assimilation System (GLDAS) precipitation dataset and a higher resolution multi-satellite precipitation product (TRMM). The study focuses on 437 flood-inducing storm events that occurred over a period of ten years (2002-2011) in the Susquehanna River basin located in the northeast US. A validation strategy was devised for assessing error metrics in rainfall and simulated runoff as function of basin area, storm severity and season. The WSR-88D gauge-adjusted radar-rainfall (stage IV) product was used as the reference rainfall dataset, while runoff simulations forced with the stage IV precipitation dataset were considered as the runoff reference. Results show that the generated rainfall ensembles from the downscaled reanalysis products encapsulate the reference rainfall. The statistical analysis, including frequency and quantile plots plus mean relative error and root mean square error statistics, demonstrated improvements in the precipitation and runoff simulation error statistics of the satellite-driven downscaled reanalysis dataset compared to the original reanalysis precipitation product. Results vary by season and less by basin scale. In the fall season specifically, the downscaled product has three times lower mean relative error than the original product; this ratio increases to four times for the simulated runoff values. The proposed downscaling scheme is modular in design and can be applied on gridded satellite and reanalysis dataset.

  1. New Products for Near Real-Time Enhanced Landslide Identification and Precipitation Monitoring

    NASA Astrophysics Data System (ADS)

    Roberts-Pierel, J.; Ahamed, A.; Fayne, J.; Rumsey, A.

    2015-12-01

    Nepal and the Himalayan region are hotspots for landslide activity due to mountainous topography, complex terrain, and monsoon rains. Current research in landslide modeling and detection generally requires high resolution imagery with software aided classification or manual digitization by analysts. These methods are plagued by low spatial and temporal accuracy. Addressing issues in conventional measurement, this study combined optical data from Landsat 8, a Digital Elevation Model (DEM) generated from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and precipitation data from the Global Precipitation Measurement Mission (GPM) to create two products. The Sudden Landslide Identification Product (SLIP) uses Landsat 8 and the ASTER DEM to identify landslides in near real-time, and provides damage assessments by mapping landslides triggered by precipitation. Detecting Real-time Increased Precipitation (DRIP) monitors precipitation levels extracted from the GPM-IMERG 30-minute product to create alerts in near real-time when current rainfall levels exceed regional threshold values. After a landslide detection is made by SLIP, historical rainfall data from DRIP is analyzed to estimate a date for the detected landslide. Together, DRIP and SLIP will be used by local and regional organizations in Nepal such as the International Centre for Integrated Mountain Development (ICIMOD), as well as the international scientific community to protect lives, preserve infrastructure, and manage local ecosystems.

  2. Reconstruction of precipitation fields out of rain-gauge data in comparison to radar based products

    NASA Astrophysics Data System (ADS)

    Maurer, R.; Schüttemeyer, D.; Gerlach, N.; Simmer, C.

    2009-04-01

    During the last decades large progress was made in the area of precipitation observation mostly related to new methods for remote sensing of precipitation. Radar observations together with passive microwave precipitation measurements have proven to be reliable in this context. However, there is still a need for more extensively exploiting the spatial and temporal variability of the obtained signals, motivated - for instance - by the demand of reliable flood warning systems. To estimate precipitation with the required accuracy the current study examines a technique to construct precipitation fields out of data of a number of spatial distributed rain-gauges by a combination of kriging and fuzzy-logic. This method was applied for a period of 3 years (2005-2008, with 133 rain gauges for about 40.000km²) for one state (Rhineland-Palatinate) in Germany. The method was compared to the operational RADOLAN product of the German Weather Service (DWD). This hourly data set is based on a radar composite created from 16 German radar sites and adjusted to online available high-resolution rain gauge observations. Both procedures were tested independently from each other by cross-correlation. It is shown that the rain-gauge based method on average closely measures up to the accuracy of the RADOLAN product, but in convective situations RADOLAN clearly shows an enhanced performance. For stratiform precipitation fields RADOLAN possesses larger deviations compared to the rain-gauge based product. Due to restrictions in the number of rain gauges an integration of radar-data is indispensable. Thus, it is concluded that the described technique together with thoroughly quality controlled Radar measurements can give reliable estimates of quantitative precipitation suitable for numerous applications in hydrology and meteorology.

  3. A linear merging methodology for high-resolution precipitation products using spatiotemporal regression

    SciTech Connect

    Turlapaty, Anish C.; Younan, Nicolas H.; Anantharaj, Valentine G

    2012-01-01

    Currently, the only viable option for a global precipitation product is the merger of several precipitation products from different modalities. In this article, we develop a linear merging methodology based on spatiotemporal regression. Four highresolution precipitation products (HRPPs), obtained through methods including the Climate Prediction Center's Morphing (CMORPH), Geostationary Operational Environmental Satellite-Based Auto-Estimator (GOES-AE), GOES-Based Hydro-Estimator (GOES-HE) and Self-Calibrating Multivariate Precipitation Retrieval (SCAMPR) algorithms, are used in this study. The merged data are evaluated against the Arkansas Red Basin River Forecast Center's (ABRFC's) ground-based rainfall product. The evaluation is performed using the Heidke skill score (HSS) for four seasons, from summer 2007 to spring 2008, and for two different rainfall detection thresholds. It is shown that the merged data outperform all the other products in seven out of eight cases. A key innovation of this machine learning method is that only 6% of the validation data are used for the initial training. The sensitivity of the algorithm to location, distribution of training data, selection of input data sets and seasons is also analysed and presented.

  4. Validation and Development of the GPCP Experimental One-Degree Daily (1DD) Global Precipitation Product

    NASA Technical Reports Server (NTRS)

    Huffman, George J.; Adler, Robert F.; Bolvin, David T.; Einaud, Franco (Technical Monitor)

    2000-01-01

    The One-Degree Daily (1DD) precipitation dataset has been developed for the Global Precipitation Climatology Project (GPCP) and is currently in beta test preparatory to release as an official GPCP product. The 1DD provides a globally-complete, observation-only estimate of precipitation on a daily 1 deg. x 1 deg. grid for the period 1997 through early 2000 (by the time of the conference). In the latitude band 40N-40S the 1DD uses the Threshold-Matched Precipitation Index (TMPI), a GPI-like IR product with the pixel-level T(sub b) threshold and (single) conditional rain rate determined locally for each month by the frequency of precipitation in the GPROF SSM/I product and by, the precipitation amount in the GPCP monthly satellite-gauge (SG) combination. Outside 40N-40S the 1DD uses a scaled TOVS precipitation estimate that has month-by-month adjustments based on the TMPI and the SG. Early validation results are encouraging. The 1DD shows relatively large scatter about the daily validation values in individual grid boxes, as expected for a technique that depends on cloud-sensing schemes such as the TMPI and TOVS. On the other hand, the time series of 1DD shows good correlation with validation in individual boxes. For example, the 1997-1998 time series of 1DD and Oklahoma Mesonet values in a grid box in northeastern Oklahoma have the correlation coefficient = 0.73. Looking more carefully at these two time series, the number of raining days for the 1DD is within 7% of the Mesonet value, while the distribution of daily rain values is very similar. Other tests indicate that area- or time-averaging improve the error characteristics, making the data set highly attractive to users interested in stream flow, short-term regional climatology, and model comparisons. The second generation of the 1DD product is currently under development; it is designed to directly incorporate TRMM and other high-quality precipitation estimates. These data are generally sparse because they are

  5. Developing GIOVANNI-based Online Prototypes to Intercompare TRMM-Related Global Gridded-Precipitation Products

    NASA Technical Reports Server (NTRS)

    Liu, Zhong; Ostrenga, Dana; Teng, William; Kempler, Steven; Milich, Lenard

    2014-01-01

    New online prototypes have been developed to extend and enhance the previous effort by facilitating investigation of product characteristics and intercomparison of precipitation products in different algorithms as well as in different versions at different spatial scales ranging from local to global without downloading data and software. Several popular Tropical Rainfall Measuring Mission (TRMM) products and the TRMM Composite Climatology are included. In addition, users can download customized data in several popular formats for further analysis. Examples show product quality problems and differences in several monthly precipitation products. It is seen that differences in daily and monthly precipitation products are distributed unevenly in space and it is necessary to have tools such as those presented here for customized and detailed investigations. A simple time series and two area maps allow the discovery of abnormal values of 3A25 in one of the months. An example shows a V-shaped valley issue in the Version 6 3B43 time series and another example shows a sudden drop in 3A25 monthly rain rate, all of which provide important information when the products are used for long-term trend studies. Future plans include adding more products and statistical functionality in the prototypes.

  6. Statistical Assessment of Precipitation Products: Case studies over Africa, Australia, and the Himalayas

    NASA Astrophysics Data System (ADS)

    Forootan, Ehsan; Khandu, Khandu; Awange, Joseph; Fereria, Vagner; Anyah, Richard

    2015-04-01

    Accurate and reliable spatial and temporal representation of precipitation variability is essential for water resource management as well as for understanding of various global (and regional) hydrological responses. The growing number of high-resolution precipitation products in the past decade requires a more rigorous evaluation process to understand their skills and limitations over different parts of the world. Using advanced statistical techniques of (complex) empirical orthogonal functions (EOF) and three-cornered-hat (TCH) methods, various monthly precipitation products derived from satellite-based measurements and global reanalyses over different climatic and topographic regimes such as Africa (2003-2010), Australia (1981-2014), the Himalayan region of Bhutan (1998-2012) were evaluated. The products were also assessed for their possible biases in terms of probability distribution and also in the spectral domain. The results indicated that while the precipitation products generally agreed reasonably well with gauge-based rainfall observations, their accuracies were widely different over the three regions. All the satellite-based products (CMORPH, CHIRP, TRMM) underestimated monsoon rain over the Himalayas, while some of them (CMORPH, GSMaP_MVK) systematically overestimated convective rainfall over central regions of the African rain-belt. Satellite-based CHIRP and the MERRA reanalysis product provided consistent long-term rainfall variability and change over Australia for the period 1981-2014 while the gauge-adjusted TRMM product (3B43 v7) was found to be more consistent with gauge observations over the Himalayas (e.g., Bhutan). Over the African continent, both conventional statistical measures (biases and root-mean-square-errors) and TCH method revealed PERSIANN to be more accurate than TRMM and other regional precipitation products such as ARC (version 2) and TAMSAT. Seasonal biases were still apparent in satellite-based/reanalysis precipitation estimates

  7. Legacies of precipitation fluctuations on primary production: theory and data synthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variability of above-ground net primary production (ANPP) of arid to sub-humid ecosystems displays a closer association with precipitation when considered across space (based on multiyear averages for different locations) than through time (based on year-to-year change at single locations). Here, we...

  8. Legacies of precipitation fluctuations on primary production: Theory and data synthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variability of aboveground net primary production (ANPP) of arid to sub-humid ecosystems displays a closer association with precipitation when considered across space, based on multiyear averages for different locations, than through time, based on year to year change at single locations. Here, we p...

  9. Application of precipitation methods for the production of water-insoluble drug nanocrystals: production techniques and stability of nanocrystals.

    PubMed

    Xia, Dengning; Gan, Yong; Cui, Fude

    2014-01-01

    This review focuses on using precipitation (bottom-up) method to produce water-insoluble drug nanocrystals, and the stability issues of nanocrystals. The precipitation techniques for production of ultra-fine particles have been widely researched for last few decades. In these techniques, precipitation of solute is achieved by addition of a non-solvent for solute called anti-solvent to decrease the solvent power for the solute dissolved in a solution. The anti-solvent can be water, organic solvents or supercritical fluids. In this paper, efforts have been made to review the precipitation techniques involving the anti-solvent precipitation by simple mixing, impinging jet mixing, multi-inlet vortex mixing, the using of high-gravity, ultrasonic waves and supercritical fluids. The key to the success of yielding stable nanocrystals in these techniques is to control the nucleation kinetics and particle growth through mixing during precipitation based on crystallization theories. The stability issues of the nanocrystals, such as sedimentation, Ostwald ripening, agglomeration and cementing of crystals, change of crystalline state, and the approaches to stabilizing nanocrystals are also discussed in detail. PMID:23651396

  10. Newly Released TRMM Version 7 Products, Other Precipitation Datasets and Data Services at NASA GES DISC

    NASA Technical Reports Server (NTRS)

    Liu, Zhong; Ostrenga, D.; Teng, W. L.; Trivedi, Bhagirath; Kempler, S.

    2012-01-01

    The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) is home of global precipitation product archives, in particular, the Tropical Rainfall Measuring Mission (TRMM) products. TRMM is a joint U.S.-Japan satellite mission to monitor tropical and subtropical (40 S - 40 N) precipitation and to estimate its associated latent heating. The TRMM satellite provides the first detailed and comprehensive dataset on the four dimensional distribution of rainfall and latent heating over vastly undersampled tropical and subtropical oceans and continents. The TRMM satellite was launched on November 27, 1997. TRMM data products are archived at and distributed by GES DISC. The newly released TRMM Version 7 consists of several changes including new parameters, new products, meta data, data structures, etc. For example, hydrometeor profiles in 2A12 now have 28 layers (14 in V6). New parameters have been added to several popular Level-3 products, such as, 3B42, 3B43. Version 2.2 of the Global Precipitation Climatology Project (GPCP) dataset has been added to the TRMM Online Visualization and Analysis System (TOVAS; URL: http://disc2.nascom.nasa.gov/Giovanni/tovas/), allowing online analysis and visualization without downloading data and software. The GPCP dataset extends back to 1979. Version 3 of the Global Precipitation Climatology Centre (GPCC) monitoring product has been updated in TOVAS as well. The product provides global gauge-based monthly rainfall along with number of gauges per grid. The dataset begins in January 1986. To facilitate data and information access and support precipitation research and applications, we have developed a Precipitation Data and Information Services Center (PDISC; URL: http://disc.gsfc.nasa.gov/precipitation). In addition to TRMM, PDISC provides current and past observational precipitation data. Users can access precipitation data archives consisting of both remote sensing and in-situ observations. Users can use these data

  11. Global gridded precipitation over land: a description of the new GPCC First Guess Daily product

    NASA Astrophysics Data System (ADS)

    Schamm, K.; Ziese, M.; Becker, A.; Finger, P.; Meyer-Christoffer, A.; Schneider, U.; Schröder, M.; Stender, P.

    2014-01-01

    This paper describes the new First Guess Daily product of the Global Precipitation Climatology Centre (GPCC). The new product gives an estimate of the global daily precipitation gridded at a spatial resolution of 1° latitude by 1° longitude. It is based on rain gauge data reported in near-real time via the Global Telecommunication System (GTS) and available about three to five days after the end of each observation month. In addition to the gridded daily precipitation totals in mm day-1, the standard deviation in mm day-1, the kriging interpolation error in % and the number of measurements per grid cell are also encoded into the monthly netCDF product file and provided for all months since January 2009. Prior to their interpolation, the measured precipitation values undergo a preliminary automatic quality control. For the calculation of the areal mean of the grid, anomalies are interpolated with ordinary block kriging. This approach allows for a near-real-time release. Therefore, the purely GTS-based data processing lacks an intensive quality control as well as a high data density and is denoted as First Guess. The daily data set is referenced under doi:10.5676/DWD_GPCC/FG_D_100. Two further products, the Full Data Daily and a merged satellite-gauge product, are currently under development at Deutscher Wetterdienst (DWD). These additional products will not be available in near-real time, but based on significantly more and strictly quality controlled observations. All GPCC products are provided free of charge via the GPCC webpage: ftp://ftp-anon.dwd.de/pub/data/gpcc/html/download_gate.html.

  12. Seasonal distribution of net primary production by functional groups in Chihuahuan Desert, and the role of seasonal precipitation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In hot deserts, precipitation is the principal driver for net primary production.  This study tested two hypotheses regarding aboveground net primary production (ANPP) and the effects of precipitation on ANPP in the Chihuahuan Desert, with emphasis on differences among seasons and among functional g...

  13. Gridded Analysis Products provided by the Global Precipitation Climatology Centre (GPCC), and new Products getting operational 2013

    NASA Astrophysics Data System (ADS)

    Ziese, Markus; Schneider, Udo; Meyer-Christoffer, Anja; Finger, Peter; Schamm, Kirstin; Becker, Andreas; Rudolf, Bruno

    2013-04-01

    Since its start in 1989 the Global Precipitation Climatology Centre (GPCC) performs global analyses of monthly precipitation for the earth's land-surface on the basis of in-situ measurements. Meanwhile, the data set has continuously grown both in temporal coverage (original start of the evaluation period was 1986), as well as extent and quality of the underlying data base. The high spatio-temporal variability of precipitation requires a high density of measurement data. Data collected from national meteorological and hydrological services are the core of the GPCC data base, and are extended by global and regional data collections. Also the GPCC receives SYNOP and CLIMAT reports via WMO-GTS, which are mainly applied for near-real-time products. For quality control a high effort is undertaken to remove miscoded and temporal or spatial dislocated data before interpolation The product suite of the GPCC contains near-real-time as well as non-real-time products. Near-real-time products are the 'First Guess' and 'Monitoring Product'. These products are based on WMO-GTS data, e.g., SYNOP and CLIMAT reports and monthly totals calculated at CPC. Non-real-time products are the 'Full Data Reanalysis', 'Climatology' and 'VASClimO'. Mainly data from national meteorological and hydrological services as well as regional and global data collections are used to calculate these products. Also WMO-GTS data are used if no other data are available. 'VASClimO' is the current homogenized product, which will be replaced by 'HOMPRA'. An overview to the above mentioned GPCC products and data base will be given with a comparison of the products. An analysis of daily precipitation ('First Guess Daily') will be made operational in 2013. Results from pre-operational runs will be shown and the applied methodology will be described. Also a drought index (GPCC-Drought Index, GPCC-DI) will be calculated operationally. The GPCC-DI is a combination of SPI-DWD and SPEI. Parameters for calculating the

  14. Evaluating Precipitation from Orbital Data Products of TRMM and GPM over the Indian Subcontinent

    NASA Astrophysics Data System (ADS)

    Jayaluxmi, I.; Kumar, D. N.

    2015-12-01

    The rapidly growing records of microwave based precipitation data made available from various earth observation satellites have instigated a pressing need towards evaluating the associated uncertainty which arise from different sources such as retrieval error, spatial/temporal sampling error and sensor dependent error. Pertaining to microwave remote sensing, most of the studies in literature focus on gridded data products, fewer studies exist on evaluating the uncertainty inherent in orbital data products. Evaluation of the latter are essential as they potentially cause large uncertainties during real time flood forecasting studies especially at the watershed scale. The present study evaluates the uncertainty of precipitation data derived from the orbital data products of the Tropical Rainfall Measuring Mission (TRMM) satellite namely the 2A12, 2A25 and 2B31 products. Case study results over the flood prone basin of Mahanadi, India, are analyzed for precipitation uncertainty through these three facets viz., a) Uncertainty quantification using the volumetric metrics from the contingency table [Aghakouchak and Mehran 2014] b) Error characterization using additive and multiplicative error models c) Error decomposition to identify systematic and random errors d) Comparative assessment with the orbital data from GPM mission. The homoscedastic random errors from multiplicative error models justify a better representation of precipitation estimates by the 2A12 algorithm. It can be concluded that although the radiometer derived 2A12 precipitation data is known to suffer from many sources of uncertainties, spatial analysis over the case study region of India testifies that they are in excellent agreement with the reference estimates for the data period considered [Indu and Kumar 2015]. References A. AghaKouchak and A. Mehran (2014), Extended contingency table: Performance metrics for satellite observations and climate model simulations, Water Resources Research, vol. 49

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

    NASA Astrophysics Data System (ADS)

    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.

  16. New and Updated Gridded Analysis Products provided by the Global Precipitation Climatology Centre (GPCC)

    NASA Astrophysics Data System (ADS)

    Ziese, Markus; Schneider, Udo; Meyer-Christoffer, Anja; Finger, Peter; Schamm, Kirstin; Rustemeier, Elke; Becker, Andreas

    2016-04-01

    Since its start in 1989 the Global Precipitation Climatology Centre (GPCC) performs global analyses of monthly precipitation for the earth's land-surface on the basis of in-situ measurements. Meanwhile, the data set has continuously grown both in temporal coverage (original start of the evaluation period was 1986), as well as extent and quality of the underlying data base. The high spatio-temporal variability of precipitation requires an accordingly high density of measurement data. Data collected from national meteorological and hydrological services are the core of the GPCC data base, supported by global and regional data collections. Also the GPCC receives SYNOP and CLIMAT reports via WMO-GTS, which are mainly applied for near-real-time products. A high quality control effort is undertaken to remove miscoded and temporal or spatial dislocated data before entry into the GPCC archive, serving the basis for further interpolation and product generation. The GPCC archive holds records from almost 100 000 stations, among those three quarters with records long enough to serve the data basis of the GPCC suite of global precipitation products, comprising near-real-time as well as non-real-time products. Near-real-time products are the 'First Guess Monthly', 'First Guess Daily', 'Monitoring Product' and 'GPCC Drought Index'. These products are based on WMO-GTS data, e.g., SYNOP and CLIMAT reports and monthly totals calculated at CPC. Non-real-time products are the 'Full Data Monthly', 'Full Data Daily', 'Climatology', and 'HOMPRA-Europe'. Data from national meteorological and hydrological services and regional and global data collections are mainly used to calculate these products. Also WMO-GTS data are used if no other data are available. The majority of the products were released in an updated version, but 'Full Data Daily' and HOMPRA-Europe' are new products provided the first time. 'Full Data Daily' is a global analysis of daily precipitation totals from 1988 to 2013

  17. Primary Productivity and Precipitation-Use Efficiency in Temperate Grassland in the Loess Plateau of China

    PubMed Central

    Jia, Xiaoxu; Xie, Baoni; Shao, Ming’an; Zhao, Chunlei

    2015-01-01

    Clarifying spatial variations in aboveground net primary productivity (ANPP) and precipitation-use efficiency (PUE) of grasslands is critical for effective prediction of the response of terrestrial ecosystem carbon and water cycle to future climate change. Though the combination use of remote sensing products and in situ ANPP measurements, we quantified the effects of climatic [mean annual precipitation (MAP) and precipitation seasonal distribution (PSD)], biotic [leaf area index (LAI)] and abiotic [slope gradient, aspect, soil water storage (SWS) and other soil physical properties] factors on the spatial variations in ANPP and PUE across different grassland types (i.e., meadow steppe, typical steppe and desert steppe) in the Loess Plateau. Based on the study, ANPP increased exponentially with MAP for the entire temperate grassland; suggesting that PUE increased with increasing MAP. Also PSD had a significant effect on ANPP and PUE; where more even PSD favored higher ANPP and PUE. Then MAP, more than PSD, explained spatial variations in typical steppe and desert steppe. However, PSD was the dominant driving factor of spatial variations in ANPP of meadow steppe. This suggested that in terms of spatial variations in ANPP of meadow steppe, change in PSD due to climate change was more important than that in total annual precipitation. LAI explained 78% of spatial PUE in the entire Loess Plateau temperate grassland. As such, LAI was the primary driving factor of spatial variations in PUE. Although the effect of SWS on ANPP and PUE was significant, it was nonetheless less than that of precipitation and vegetation. We therefore concluded that changes in vegetation structure and consequently in LAI and/or altered pattern of seasonal distribution of rainfall due to global climate change could significantly influence ecosystem carbon and water cycle in temperate grasslands. PMID:26295954

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

    NASA Astrophysics Data System (ADS)

    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

  19. Effect of structural characteristics of corncob hemicelluloses fractionated by graded ethanol precipitation on furfural production.

    PubMed

    Li, Huiling; Dai, Qingqing; Ren, Junli; Jian, Longfei; Peng, Feng; Sun, Runcang; Liu, Guoliang

    2016-01-20

    In the present study, a graded ethanol precipitation technique was employed to obtain hemicelluloses from the alkali-extracted corncob liquid. The relationship between the structural characteristics of alkali-soluble corncob hemicelluloses and the production of furfural was investigated by a heterogeneous process in a biphasic system. Results showed that alkali-soluble corncob hemicelluloses mainly consisted of glucuronoarabinoxylans and L-arabino-(4-O-methylglucurono)-D-xylans, and the drying way had less influence on the sugar composition, molecular weights and the functional groups of hemicelluloses obtained by the different ethanol concentration precipitation except for the thermal property, the amorphous structure and the ability for the furfural production. Furthermore, alkali-soluble corncob hemicelluloses with higher xylose content, lower branch degree, higher polydispersity and crystallinity contributed to the furfural production. A highest furfural yield of 45.41% with the xylose conversion efficiency of 99.06% and the furfural selectivity of 45.84% was obtained from the oven-dried hemicelluloses precipitated at the 30% (v/v) ethanol concentration. PMID:26572347

  20. Data Analysis of GPM Constellation Satellites-IMERG and ERA-Interim precipitation products over West of Iran

    NASA Astrophysics Data System (ADS)

    Sharifi, Ehsan; Steinacker, Reinhold; Saghafian, Bahram

    2016-04-01

    Precipitation is a critical component of the Earth's hydrological cycle. The primary requirement in precipitation measurement is to know where and how much precipitation is falling at any given time. Especially in data sparse regions with insufficient radar coverage, satellite information can provide a spatial and temporal context. Nonetheless, evaluation of satellite precipitation is essential prior to operational use. This is why many previous studies are devoted to the validation of satellite estimation. Accurate quantitative precipitation estimation over mountainous basins is of great importance because of their susceptibility to hazards. In situ observations over mountainous areas are mostly limited, but currently available satellite precipitation products can potentially provide the precipitation estimation needed for meteorological and hydrological applications. One of the newest and blended methods that use multi-satellites and multi-sensors has been developed for estimating global precipitation. The considered data set known as Integrated Multi-satellitE Retrievals (IMERG) for GPM (Global Precipitation Measurement) is routinely produced by the GPM constellation satellites. Moreover, recent efforts have been put into the improvement of the precipitation products derived from reanalysis systems, which has led to significant progress. One of the best and a worldwide used model is developed by the European Centre for Medium Range Weather Forecasts (ECMWF). They have produced global reanalysis daily precipitation, known as ERA-Interim. This study has evaluated one year of precipitation data from the GPM-IMERG and ERA-Interim reanalysis daily time series over West of Iran. IMERG and ERA-Interim yield underestimate the observed values while IMERG underestimated slightly and performed better when precipitation is greater than 10mm. Furthermore, with respect to evaluation of probability of detection (POD), threat score (TS), false alarm ratio (FAR) and probability

  1. Increasing precipitation event size increases aboveground net primary productivity in a semi-arid grassland.

    PubMed

    Heisler-White, Jana L; Knapp, Alan K; Kelly, Eugene F

    2008-11-01

    Water availability is the primary constraint to aboveground net primary productivity (ANPP) in many terrestrial biomes, and it is an ecosystem driver that will be strongly altered by future climate change. Global circulation models predict a shift in precipitation patterns to growing season rainfall events that are larger in size but fewer in number. This "repackaging" of rainfall into large events with long intervening dry intervals could be particularly important in semi-arid grasslands because it is in marked contrast to the frequent but small events that have historically defined this ecosystem. We investigated the effect of more extreme rainfall patterns on ANPP via the use of rainout shelters and paired this experimental manipulation with an investigation of long-term data for ANPP and precipitation. Experimental plots (n = 15) received the long-term (30-year) mean growing season precipitation quantity; however, this amount was distributed as 12, six, or four events applied manually according to seasonal patterns for May-September. The long-term mean (1940-2005) number of rain events in this shortgrass steppe was 14 events, with a minimum of nine events in years of average precipitation. Thus, our experimental treatments pushed this system beyond its recent historical range of variability. Plots receiving fewer, but larger rain events had the highest rates of ANPP (184 +/- 38 g m(-2)), compared to plots receiving more frequent rainfall (105 +/- 24 g m(-2)). ANPP in all experimental plots was greater than long-term mean ANPP for this system (97 g m(-2)), which may be explained in part by the more even distribution of applied rain events. Soil moisture data indicated that larger events led to greater soil water content and likely permitted moisture penetration to deeper in the soil profile. These results indicate that semi-arid grasslands are capable of responding immediately and substantially to forecast shifts to more extreme precipitation patterns. PMID

  2. Comparison and evaluation of high resolution precipitation estimation products in Urmia Basin-Iran

    NASA Astrophysics Data System (ADS)

    Ghajarnia, N.; Liaghat, A.; Daneshkar Arasteh, P.

    2015-05-01

    This study focuses on the comparison and evaluation of six daily 0.25° × 0.25° high resolution precipitation data sets (PERSIANN, CMORPH-RAW, CMORPH-CRT, TMPA-RT, TMPA-V7 and APHRODITE). The comparison is performed during years 2000 till 2011 in Urmia basin of Iran and the local daily rainfall gauge observations are considered as the reference data set. Several statistical, categorical and graphical evaluation techniques are used to compare and evaluate the product performances and quantify their biases from reference data. APHRODITE and TMPA-V7, by benefiting from gauge observations during their adjustment procedures present better estimations while among near real-time products, PERSIANN is able to remarkably outperform other estimations. Both CMORPH products has shown to have great overestimation (more than 200%) over the observations while PERSIANN and TMPA-RT tend to underestimate rainfall on average about 26% and 78% respectively. TMPA-V7 and APHRODITE also overestimate observations about 26 and 3 percentages. Compared to near real-time version of products, TMPA-V7 has succeeded to significantly improve TMPA-RT performance while CMORPH-CRT has completely unsuccessful in its mission. Although all rainfall estimation products are characterized by considerable biases in comparison to the gauge observations, detailed analysis indicate that some of them have the capability of becoming a valuable source of high resolution precipitation estimation data set, especially over purely gauged areas.

  3. Precipitation of organic arsenic compounds and their degradation products during struvite formation.

    PubMed

    Lin, Jin-Biao; Yuan, Shoujun; Wang, Wei; Hu, Zhen-Hu; Yu, Han-Qing

    2016-11-01

    Roxarsone (ROX) and arsanilic acid (ASA) have been extensively used as organoarsenic animal feed additives. Organic arsenic compounds and their degradation products, arsenate (As(V)) and arsenite (As(III)), exist in the effluent from anaerobic reactors treating animal manure contaminated by ROX or ASA with ammonium (NH4(+)-N) and phosphate (PO4(3-)-P) together. Therefore, arsenic species in the effluent might be involved in the struvite formation process. In this study, the involvement of organic arsenic compounds and their degradation products As(V) and As(III) in the struvite crystallization was investigated. The results demonstrated that arsenic compounds did not substantially affect the PO4(3-)-P recovery, but confirmed the precipitation of arsenic during struvite formation. The precipitation of arsenic compounds in struvite was considerably affected by a solution pH from 9.0 to 11.0. With an increase in pH, the content of ASA and ROX in the precipitation decreased, but the contents of As(III) and As(V) increased. In addition, the arsenic content of As(V) in the struvite was higher than that of As(III), ASA and ROX. The results indicated that the struvite could be contaminated when the solution contains arsenic species, but that could be minimized by controlling the solution pH and maintaining anaerobic conditions during struvite formation. PMID:27262276

  4. Desalination and hydrogen, chlorine, and sodium hydroxide production via electrophoretic ion exchange and precipitation.

    PubMed

    Shkolnikov, Viktor; Bahga, Supreet S; Santiago, Juan G

    2012-08-28

    We demonstrate and analyze a novel desalination method which works by electrophoretically replacing sodium and chloride in feed salt water with a pair of ions, calcium and carbonate, that react and precipitate out. The resulting calcium carbonate precipitate is benign to health, and can be filtered or settled out, yielding low ionic strength product water. The ion exchange and precipitation employs self-sharpening interfaces induced by movement of multiple ions in an electric field to prevent contamination of the product water. Simultaneously, the electrolysis associated with the electromigration produces hydrogen gas, chlorine gas, and sodium hydroxide. We conducted an experimental study of this method's basic efficacy to desalinate salt water from 100 to 600 mol m(-3) sodium chloride. We also present physicochemical models of the process, and analyze replacement reagents consumption, permeate recovery ratio, and energy consumption. We hypothesize that the precipitate can be recycled back to replacement reagents using the well-known, commercially implemented Solvay process. We show that the method's permeate recovery ratio is 58% to 46%, which is on par with that of reverse osmosis. We show that the method's energy consumption requirement over and above that necessary to generate electrolysis is 3 to 10 W h l(-1), which is on par with the energy consumed by state-of-the-art desalination methods. Furthermore, the method operates at ambient temperature and pressure, and uses no specialized membranes. The process may be feasible as a part of a desalination-co-generation facility: generating fresh water, hydrogen and chlorine gas, and sodium hydroxide. PMID:22806549

  5. Building Capacity for Production of Gridded Precipitation Products in the East Africa Community

    NASA Astrophysics Data System (ADS)

    Budde, M. E.; Verdin, J. P.; Galu, G.; Magadzire, T.; Pedreros, D. H.; Funk, C. C.; Husak, G. J.; Peterson, P.; Landsfeld, M. F.; White, L.

    2014-12-01

    The Famine Early Warning Systems Network (FEWS NET) participates in the Group on Earth Observations' Global Agricultural Monitoring (GEOGLAM) activity in a number of ways. Recently, important progress has been made in meeting the need for improved precipitation data sets in East Africa. This has been done through capacity building activities with national meteorological and hydrological services (NMHS) in the region, carried out in partnership with the IGAD Climate Prediction and Applications Center (ICPAC), and with support from the WMO Office for Eastern and Southern Africa. Through a series of regional gatherings and individual country workshops, scientists from the NMHS have been introduced to the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) rainfall data set and the GeoCLIM software tool. The CHIRPS data set was developed by USGS and the University of California, Santa Barbara, by blending NOAA geostationary thermal infrared imagery with station observations, using robust geostatistical methods. The core data set consists of pentadal (5-daily) accumulations from 1981-2014 at 0.05 degree spatial resolution, between +/- 50 degrees latitude. The GeoCLIM software can operate on the CHIRPS to map the Standardized Precipitation Index, trends, anomalies, isohyets, and other types of spatio-temporal features. It can also produce new gridded rainfall data sets by geostatistical blending of station observations with existing rainfall grids. NMHS scientists have applied this latter capability to produce best-available national and regional gridded rainfall time-series for 1981-2014 for the East Africa Community (EAC). These data are a fundamental resource for the USAID-EAC climate change adaptation project known by the acronym PREPARED. They incorporate a larger and more complete collection of station observations than ever before. Further work is ongoing at the NMHS to take advantage of the data management capabilities of GeoCLIM, and incorporate

  6. Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional dive...

  7. Synthesizing effects of precipitation manipulation on plant production and soil respiration - results and challenges

    NASA Astrophysics Data System (ADS)

    Vicca, Sara; Estiarte, Marc; Bahn, Michael; Peñuelas, Josep; Janssens, Ivan

    2013-04-01

    We compiled a database containing data from over 70 experimental sites where precipitation was manipulated. These experiments cover different biomes (mainly tropical forests, temperate forests and grasslands, temperate and Mediterranean shrublands), but the majority of experiments was performed in the temperate zone. From these experiments, we collected (among others) available data for plant biomass and biomass production, leaf gas exchange, leaf and soil chemistry and soil respiration. Because experiments differed largely in the timing, duration and magnitude of the manipulation, our aim was to first quantify the manipulation and bring all experiments to a common denominator reflecting the (plant) available water. The data needed for such quantification of the manipulation are, however, available for very few experiments. Analyses that go beyond a meta-analytical approach (in which the magnitude of the manipulation is typically neglected) are therefore hampered. In order to avoid problems related to the magnitude of the manipulation, we focussed the analyses of soil respiration (Rsoil) on within-experiment trends. We tested whether a simple temperature-soil moisture-model that fits well to the Rsoil measurements of the control plots can be used to predict the Rsoil measurements for the treatment plots. For several experiments we found that low predictability was not only related to extrapolation beyond the range of SWC in the control plots. Apparently, the manipulation had altered the response of Rsoil to temperature and/or SWC in the treatment plots to a degree which was not predictable from the controls. Besides Rsoil, we also analyzed responses of ANPP to reduced precipitation. A mixed effects modelling approach (which accounts for clustering of observations from sites with multiple years of data and/or multiple manipulations) revealed that ANPP was mainly determined by the site mean annual precipitation (MAP). Additional variation was explained by actual

  8. Evaluation of NASA's MERRA Precipitation Product in Reproducing the Observed Trend and Distribution of Extreme Precipitation Events in the United States

    NASA Technical Reports Server (NTRS)

    Ashouri, Hamed; Sorooshian, Soroosh; Hsu, Kuo-Lin; Bosilovich, Michael G.; Lee, Jaechoul; Wehner, Michael F.; Collow, Allison

    2016-01-01

    This study evaluates the performance of NASA's Modern-Era Retrospective Analysis for Research and Applications (MERRA) precipitation product in reproducing the trend and distribution of extreme precipitation events. Utilizing the extreme value theory, time-invariant and time-variant extreme value distributions are developed to model the trends and changes in the patterns of extreme precipitation events over the contiguous United States during 1979-2010. The Climate Prediction Center (CPC) U.S.Unified gridded observation data are used as the observational dataset. The CPC analysis shows that the eastern and western parts of the United States are experiencing positive and negative trends in annual maxima, respectively. The continental-scale patterns of change found in MERRA seem to reasonably mirror the observed patterns of change found in CPC. This is not previously expected, given the difficulty in constraining precipitation in reanalysis products. MERRA tends to overestimate the frequency at which the 99th percentile of precipitation is exceeded because this threshold tends to be lower in MERRA, making it easier to be exceeded. This feature is dominant during the summer months. MERRA tends to reproduce spatial patterns of the scale and location parameters of the generalized extreme value and generalized Pareto distributions. However, MERRA underestimates these parameters, particularly over the Gulf Coast states, leading to lower magnitudes in extreme precipitation events. Two issues in MERRA are identified: 1) MERRA shows a spurious negative trend in Nebraska and Kansas, which is most likely related to the changes in the satellite observing system over time that has apparently affected the water cycle in the central United States, and 2) the patterns of positive trend over the Gulf Coast states and along the East Coast seem to be correlated with the tropical cyclones in these regions. The analysis of the trends in the seasonal precipitation extremes indicates that

  9. Alkali feldspar dissolution and secondary mineral precipitation in batch systems: 3. Saturation states of product minerals and reaction paths

    NASA Astrophysics Data System (ADS)

    Zhu, Chen; Lu, Peng

    2009-06-01

    In order to evaluate the complex interplay between dissolution and precipitation reaction kinetics, we examined the hypothesis of partial equilibria between secondary mineral products and aqueous solutions in feldspar-water systems. Speciation and solubility geochemical modeling was used to compute the saturation indices (SI) for product minerals in batch feldspar dissolution experiments at elevated temperatures and pressures and to trace the reaction paths on activity-activity diagrams. The modeling results demonstrated: (1) the experimental aqueous solutions were supersaturated with respect to product minerals for almost the entire duration of the experiments; (2) the aqueous solution chemistry did not evolve along the phase boundaries but crossed the phase boundaries at oblique angles; and (3) the earlier precipitated product minerals did not dissolve but continued to precipitate even after the solution chemistry had evolved into the stability fields of minerals lower in the paragenesis sequence. These three lines of evidence signify that product mineral precipitation is a slow kinetic process and partial equilibria between aqueous solution and product minerals were not held. In contrast, the experimental evidences are consistent with the hypothesis of strong coupling of mineral dissolution/precipitation kinetics [e.g., Zhu C., Blum A. E. and Veblen D. R. (2004a) Feldspar dissolution rates and clay precipitation in the Navajo aquifer at Black Mesa, Arizona, USA. In Water-Rock Interaction (eds. R. B. Wanty and R. R. I. Seal). A.A. Balkema, Saratoga Springs, New York. pp. 895-899]. In all batch experiments examined, the time of congruent feldspar dissolution was short and supersaturation with respect to the product minerals was reached within a short period of time. The experimental system progressed from a dissolution driven regime to a precipitation limited regime in a short order. The results of this study suggest a complex feedback between dissolution and

  10. Visualization of GPM Standard Products at the Precipitation Processing System (PPS)

    NASA Astrophysics Data System (ADS)

    Kelley, O.

    2010-12-01

    Many of the standard data products for the Global Precipitation Measurement (GPM) constellation of satellites will be generated at and distributed by the Precipitation Processing System (PPS) at NASA Goddard. PPS will provide several means to visualize these data products. These visualization tools will be used internally by PPS analysts to investigate potential anomalies in the data files, and these tools will also be made available to researchers. Currently, a free data viewer called THOR, the Tool for High-resolution Observation Review, can be downloaded and installed on Linux, Windows, and Mac OS X systems. THOR can display swath and grid products, and to a limited degree, the low-level data packets that the satellite itself transmits to the ground system. Observations collected since the 1997 launch of the Tropical Rainfall Measuring Mission (TRMM) satellite can be downloaded from the PPS FTP archive, and in the future, many of the GPM standard products will also be available from this FTP site. To provide easy access to this 80 terabyte and growing archive, PPS currently operates an on-line ordering tool called STORM that provides geographic and time searches, browse-image display, and the ability to order user-specified subsets of standard data files. Prior to the anticipated 2013 launch of the GPM core satellite, PPS will expand its visualization tools by integrating an on-line version of THOR within STORM to provide on-the-fly image creation of any portion of an archived data file at a user-specified degree of magnification. PPS will also provide OpenDAP access to the data archive and OGC WMS image creation of both swath and gridded data products. During the GPM era, PPS will continue to provide realtime globally-gridded 3-hour rainfall estimates to the public in a compact binary format (3B42RT) and in a GIS format (2-byte TIFF images + ESRI WorldFiles).

  11. Evaluation of precipitation products to force a global flood and drought prediction system

    NASA Astrophysics Data System (ADS)

    Voisin, N.; Lettenmaier, D. P.; Wood, E. F.

    2005-12-01

    Droughts and floods are pervasive natural hazards. The annual cost of U.S. droughts is in the range $6-8B, and estimated U.S. annual flood losses are only slightly less. Global flood and drought losses are almost certainly much higher. Nonetheless, there is at present no system for forecasting of floods and droughts globally, although the potential now exists. The pilot phase of a project to generate global flood and drought predictions routinely is presented. It draws heavily from the experimental North American Land Data Assimilation System (N-LDAS) and the companion Global Land Data Assimilation System (G-LDAS) for development of nowcasts, and the University of Washington Experimental Hydrologic Prediction System to develop ensemble hydrologic forecasts based on the NCEP Global Forecast System for lead times from seven days to six months. In retrospective testing, the system, which uses the Variable Infiltration Capacity (VIC) macroscale hydrology model to make predictions of streamflow and soil moisture, is driven by the GPCP 1DD global precipitation products, and ECMWF surface air temperature products. Downward solar and longwave radiation, surface relative humidity, and other model forcings are derived from relationships with the daily temperature range. The initial system is implemented globally at one-half degree spatial resolution. Characteristics errors in the precipitation data into the hydrological model represent the best attainable forecasts, where errors are being estimated from differences between the GPCP 1DD, ERA-40 and a 50-year retrospective data set produced by the University of Washington and Princeton University. Differences in precipitation between the different global data sets and their resulting hydrological differences are evaluated for the 1997-2002 period for a number of major global rivers, and for specific events like the Mekong and Elbe River floods in 2002, the Mozambique floods in 2000, the Mozambique drought in 2001 and the

  12. Dominant plant taxa predict plant productivity responses to CO2 enrichment across precipitation and soil gradients.

    PubMed

    Fay, Philip A; Newingham, Beth A; Polley, H Wayne; Morgan, Jack A; LeCain, Daniel R; Nowak, Robert S; Smith, Stanley D

    2015-01-01

    The Earth's atmosphere will continue to be enriched with carbon dioxide (CO2) over the coming century. Carbon dioxide enrichment often reduces leaf transpiration, which in water-limited ecosystems may increase soil water content, change species abundances and increase the productivity of plant communities. The effect of increased soil water on community productivity and community change may be greater in ecosystems with lower precipitation, or on coarser-textured soils, but responses are likely absent in deserts. We tested correlations among yearly increases in soil water content, community change and community plant productivity responses to CO2 enrichment in experiments in a mesic grassland with fine- to coarse-textured soils, a semi-arid grassland and a xeric shrubland. We found no correlation between CO2-caused changes in soil water content and changes in biomass of dominant plant taxa or total community aboveground biomass in either grassland type or on any soil in the mesic grassland (P > 0.60). Instead, increases in dominant taxa biomass explained up to 85 % of the increases in total community biomass under CO2 enrichment. The effect of community change on community productivity was stronger in the semi-arid grassland than in the mesic grassland, where community biomass change on one soil was not correlated with the change in either the soil water content or the dominant taxa. No sustained increases in soil water content or community productivity and no change in dominant plant taxa occurred in the xeric shrubland. Thus, community change was a crucial driver of community productivity responses to CO2 enrichment in the grasslands, but effects of soil water change on productivity were not evident in yearly responses to CO2 enrichment. Future research is necessary to isolate and clarify the mechanisms controlling the temporal and spatial variations in the linkages among soil water, community change and plant productivity responses to CO2 enrichment. PMID

  13. Global Precipitation Variations and Long-term Changes Derived from the GPCP Monthly Product

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Gu, Guojun; Huffman, George; Curtis, Scott

    2005-01-01

    Global and large regional rainfall variations and possible long-term changes are examined using the 25-year (1979-2004) monthly dataset from the Global Precipitation Climatology Project (GPCP). The emphasis is to discriminate among the variations due to ENSO, volcanic events and possible long-term changes. Although the global change of precipitation in the data set is near zero, the data set does indicate an upward trend (0.13 mm/day/25yr) and a downward trend (-0.06 mm/day/25yr) over tropical oceans and lands (25S-25N), respectively. This corresponds to a 4% increase (ocean) and 2% decrease (land) during this time period. Techniques are applied to attempt to eliminate variations due to ENSO and major volcanic eruptions. The impact of the two major volcanic eruptions over the past 25 years is estimated to be about a 5% reduction in tropical rainfall. The modified data set (with ENSO and volcano effect removed) retains the same approximate change slopes, but with reduced variance leading to significance tests with results in the 90-95% range. Inter-comparisons between the GPCP, SSWI (1988-2004), and TRMM (1998-2004) rainfall products are made to increase or decrease confidence in the changes seen in the GPCP analysis.

  14. Consequences of the heterogeneous nitriding of. cap alpha. -iron: dislocation production and oriented precipitation

    SciTech Connect

    Straver, W.T.M.; Mittemeijer, E.J.; Rozendaal, M.C.F.

    1984-04-01

    In commercial practice nitriding of a surface layer of workpieces of steel is employed to improve the mechanical properties, such as the fatigue resistance. To study the effects of such a heterogeneous nitriding treatment on microstructure, relatively thin and thick specimens of ..cap alpha..-iron have been nitrided heterogeneously at 833 K in gas mixtures composed of NH/sub 3/ and H/sub 2/. Transmission electron microscopy was applied to investigate the microstructure as a function of depth below the surface. Electron transparent foils parallel to the surface were taken at predefined depths in the nitrogen diffusion zone employing a special preparation technique. On nitriding dislocations were produced in the diffusion zone. The dislocation density varied with location in the zone. After aging followin nitriding, near the surface ..cap alpha..''-Fe/sub 16/N/sub 2/ precipitates in the form of discs aligned along (100) planes of the iron matrix making the smallest angle with the surface at those places where no appreciable dislocation production had occurred. For larger penetration depths precipitates aligned along (100) planes of the iron matrix making the smallest angle with the diffusion direction (perpendicular to the surface). These effects are related to the diffusion-induced state of stress in the specimen.

  15. Variations of net ecosystem production due to seasonal precipitation differences in a tropical dry forest of northwest Mexico

    NASA Astrophysics Data System (ADS)

    Verduzco, Vivian S.; Garatuza-Payán, Jaime; Yépez, Enrico A.; Watts, Christopher J.; Rodríguez, Julio C.; Robles-Morua, Agustin; Vivoni, Enrique R.

    2015-10-01

    Due to their large extent and high primary productivity, tropical dry forests (TDF) are important contributors to atmospheric carbon exchanges in subtropical and tropical regions. In northwest Mexico, a bimodal precipitation regime that includes winter precipitation derived from Pacific storms and summer precipitation from the North American monsoon (NAM) couples water availability with ecosystem processes. We investigated the net ecosystem production of a TDF ecosystem using a 4.5 year record of water and carbon fluxes obtained from the eddy covariance method complemented with remotely sensed data. We identified a large CO2 efflux at the start of the summer season that is strongly related to the preceding winter precipitation and greenness. Since this CO2 efflux occurs prior to vegetation green-up, we infer that respiration is mainly due to decomposition of soil organic matter accumulated from the prior growing season. Overall, ecosystem respiration has an important effect on the net ecosystem production but can be overwhelmed by the strength of the primary productivity during the NAM. Precipitation characteristics during NAM have significant controls on sustaining carbon fixation in the TDF into the fall season. We identified that a threshold of ~350 to 400 mm of monsoon precipitation leads to a switch in the annual carbon balance in the TDF ecosystem from a net source (+102 g C/m2/yr) to a net sink (-249 g C/m2/yr). This monsoonal precipitation threshold is typically exceeded one out of every 2 years. The close coupling of winter and summer periods with respect to carbon fluxes suggests that the annual carbon balance is dependent on precipitation amounts in both seasons in TDF ecosystems.

  16. Changes in the TRMM Version-5 and Version-6 Precipitation Radar Products Due to Orbit Boost

    NASA Technical Reports Server (NTRS)

    Liao, Liang; Meneghini, Robert

    2010-01-01

    The performance of the version-5 and version-6 Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) products before and after the satellite orbit boost is assessed through a series of comparisons with Weather Surveillance Radar (WSR)-88D ground-based radar in Melbourne, Florida. Analysis of the comparisons of radar reflectivity near the storm top from the ground radar and both versions of the PR indicates that the PR bias relative to the WSR radar at Melbourne is on the order of 1dB for both pre- and post-boost periods, indicating that the PR products maintain accurate calibration after the orbit boost. Comparisons with the WSR-88D near-surface reflectivity factors indicate that both versions of the PR products accurately correct for attenuation in stratiform rain. However, in convective rain, both versions exhibit negative biases in the near-surface radar reflectivity with version-6 products having larger negative biases than version-5. Rain rate comparisons between the ground and space radars show similar characteristics

  17. A suite of global reconstructed precipitation products and their error estimate by multivariate regression using empirical orthogonal functions: 1850-present

    NASA Astrophysics Data System (ADS)

    Shen, S. S.

    2014-12-01

    This presentation describes a suite of global precipitation products reconstructed by a multivariate regression method using an empirical orthogonal function (EOF) expansion. The sampling errors of the reconstruction are estimated for each product datum entry. The maximum temporal coverage is 1850-present and the spatial coverage is quasi-global (75S, 75N). The temporal resolution ranges from 5-day, monthly, to seasonal and annual. The Global Precipitation Climatology Project (GPCP) precipitation data from 1979-2008 are used to calculate the EOFs. The Global Historical Climatology Network (GHCN) gridded data are used to calculate the regression coefficients for reconstructions. The sampling errors of the reconstruction are analyzed in detail for different EOF modes. Our reconstructed 1900-2011 time series of the global average annual precipitation shows a 0.024 (mm/day)/100a trend, which is very close to the trend derived from the mean of 25 models of the CMIP5 (Coupled Model Intercomparison Project Phase 5). Our reconstruction examples of 1983 El Niño precipitation and 1917 La Niña precipitation (Figure 1) demonstrate that the El Niño and La Niña precipitation patterns are well reflected in the first two EOFs. The validation of our reconstruction results with GPCP makes it possible to use the reconstruction as the benchmark data for climate models. This will help the climate modeling community to improve model precipitation mechanisms and reduce the systematic difference between observed global precipitation, which hovers at around 2.7 mm/day for reconstructions and GPCP, and model precipitations, which have a range of 2.6-3.3 mm/day for CMIP5. Our precipitation products are publically available online, including digital data, precipitation animations, computer codes, readme files, and the user manual. This work is a joint effort between San Diego State University (Sam Shen, Nancy Tafolla, Barbara Sperberg, and Melanie Thorn) and University of Maryland (Phil

  18. Comparison of precipitable water over Ghana using GPS signals and reanalysis products

    NASA Astrophysics Data System (ADS)

    Acheampong, A. A.; Fosu, C.; Amekudzi, L. K.; Kaas, E.

    2015-11-01

    Signals from Global Navigational Satellite Systems (GNSS) when integrated with surface meteorological parameters can be used to sense atmospheric water vapour. Using gLAB software and employing precise point positioning techniques, zenith troposphere delays (ZTD) for a GPS base station at KNUST, Kumasi have been computed and used to retrieve Precipitable Water (PW). The PW values obtained were compared with products from ERA-Interim and NCEP reanalysis data. The correlation coefficients, r, determined from these comparisons were 0.839 and 0.729 for ERA-interim and NCEP respectively. This study has demonstrated that water vapour can be retrieved with high precision from GNSS signal. Furthermore, a location map have been produced to serve as a guide in adopting and installing GNSS base stations in Ghana to achieve a country wide coverage of GNSS based water vapour monitoring.

  19. Inter-Sensor Comparison of Microwave Land Surface Emissivity Products to Improve Precipitation Retrievals

    NASA Astrophysics Data System (ADS)

    Norouzi, H.; Temimi, M.; Turk, J.; Prigent, C.; Furuzawa, F.; Tian, Y.

    2013-12-01

    Microwave land surface emissivity acts as the background signal to estimate rain rate, cloud liquid water, and total precipitable water. Therefore, its accuracy can directly affect the uncertainty of such measurements. Over land, unlike over oceans, the microwave emissivity is relatively high and and varies significantly as surface conditions and land cover change. Lack of ground truth measurement of microwave emissivity especially on global scale has made the uncertainty analysis of this parameter very challenging. The present study investigates the consistency among the existing global land emissivity estimates from different microwave sensors. The products are determined from various sensors and frequencies ranging from 7 to 90 GHz. The selected emissivity products in this study are from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) by NOAA - Cooperative remote Sensing and Science and Technology Center (CREST), the Special Sensor Microwave Imager (SSM/I) by The Centre National de la Recherche Scientifique (CNRS) in France, TRMM Microwave Imager (TMI) by Nagoya University, Japan, and WindSat by NASA Jet Propulsion Laboratory (JPL). The emissivity estimates are based on different algorithms and ancillary data sets. This work investigates the difference among these emissivity products from 2003 to 2008 dynamically and spectrally. The similarities and discrepancies of the retrievals are studied at different land cover types. The mean relative difference (MRD) and other statistical parameters are calculated temporally for all five years of the study. Some inherent discrepancies between the selected products can be attributed to the difference in geometry in terms of incident angle, spectral response, and the foot print size which can affect the estimations. The results reveal that in lower frequencies (=<19 GHz) ancillary data especially skin temperature data set is the major source of difference in emissivity retrievals, while in higher frequencies

  20. Incorporating TRMM and Other High-Quality Estimates into the One-Degree Daily (1DD) Global Precipitation Product

    NASA Technical Reports Server (NTRS)

    Huffman, George J.; Adler, Robert F.; Bolvin, David T.

    1999-01-01

    The One-Degree Daily (1DD) precipitation dataset was recently developed for the Global Precipitation Climatology Project (GPCP). The IDD provides a globally-complete, observation-only estimate of precipitation on a daily 1 deg x 1 deg grid for the period 1997 through late 1999 (by the time of the conference). In the latitude band 40 N - 40 S the IDD uses the Threshold-Matched Precipitation Index (TMPI), a GPI-like IR product with the T(sub b) threshold and (single) conditional rain rate determined locally for each month by the frequency of precipitation in the GPROF SSNU product and by the precipitation amount in the GPCP satellite-gauge (SG) combination. Outside 40 N - 40 S the 1DD uses a scaled TOVS precipitation estimate that has adjustments based on the TMPI and the SG. This first-generation 1DD has been in beta test preparatory to release as an official GPCP product. In this paper we discuss further development of the 1DD framework to allow the direct incorporation of TRMM and other high-quality precipitation estimates. First, these data are generally sparse (typically from low-orbit satellites), so a fair amount of work was devoted to data boundaries. Second, these data are not the same as the original 1DD estimates, so we had to give careful consideration to the best scheme for forcing the 1DD to sum to the SG for the month. Finally, the non-sun-synchronous, low-inclination orbit occupied by TRMM creates interesting variations against the sun-synchronous, high-inclination orbits occupied by the Defense Meteorological Satellite Program satellites that carry the SSM/I. Examples will be given of each of the development issues, then comparisons will be made to daily raingauge analyses.

  1. Exogenous N addition enhances the responses of gross primary productivity to individual precipitation events in a temperate grassland.

    PubMed

    Guo, Qun; Hu, Zhong-Min; Li, Sheng-Gong; Yu, Gui-Rui; Sun, Xiao-Min; Li, Ling-Hao; Liang, Nai-Shen; Bai, Wen-Ming

    2016-01-01

    Predicted future shifts in the magnitude and frequency (larger but fewer) of precipitation events and enhanced nitrogen (N) deposition may interact to affect grassland productivity, but the effects of N enrichment on the productivity response to individual precipitation events remain unclear. In this study, we quantified the effects of N addition on the response patterns of gross primary productivity (GPP) to individual precipitation events of different sizes (Psize) in a temperate grassland in China. The results showed that N enrichment significantly increased the time-integrated amount of GPP in response to an individual precipitation event (GPPtotal), and the N-induced stimulation of GPP increased with increasing Psize. N enrichment rarely affected the duration of the GPP response, but it significantly stimulated the maximum absolute GPP response. Higher foliar N content might play an important role in the N-induced stimulation of GPP. GPPtotal in both the N-addition and control treatments increased linearly with Psize with similar Psize intercepts (approximately 5 mm, indicating a similar lower Psize threshold to stimulate the GPP response) but had a steeper slope under N addition. Our work indicates that the projected larger precipitation events will stimulate grassland productivity, and this stimulation might be amplified by increasing N deposition. PMID:27264386

  2. Exogenous N addition enhances the responses of gross primary productivity to individual precipitation events in a temperate grassland

    NASA Astrophysics Data System (ADS)

    Guo, Qun; Hu, Zhong-Min; Li, Sheng-Gong; Yu, Gui-Rui; Sun, Xiao-Min; Li, Ling-Hao; Liang, Nai-Shen; Bai, Wen-Ming

    2016-06-01

    Predicted future shifts in the magnitude and frequency (larger but fewer) of precipitation events and enhanced nitrogen (N) deposition may interact to affect grassland productivity, but the effects of N enrichment on the productivity response to individual precipitation events remain unclear. In this study, we quantified the effects of N addition on the response patterns of gross primary productivity (GPP) to individual precipitation events of different sizes (Psize) in a temperate grassland in China. The results showed that N enrichment significantly increased the time-integrated amount of GPP in response to an individual precipitation event (GPPtotal), and the N-induced stimulation of GPP increased with increasing Psize. N enrichment rarely affected the duration of the GPP response, but it significantly stimulated the maximum absolute GPP response. Higher foliar N content might play an important role in the N-induced stimulation of GPP. GPPtotal in both the N-addition and control treatments increased linearly with Psize with similar Psize intercepts (approximately 5 mm, indicating a similar lower Psize threshold to stimulate the GPP response) but had a steeper slope under N addition. Our work indicates that the projected larger precipitation events will stimulate grassland productivity, and this stimulation might be amplified by increasing N deposition.

  3. Exogenous N addition enhances the responses of gross primary productivity to individual precipitation events in a temperate grassland

    PubMed Central

    Guo, Qun; Hu, Zhong-min; Li, Sheng-gong; Yu, Gui-rui; Sun, Xiao-min; Li, Ling-hao; Liang, Nai-shen; Bai, Wen-ming

    2016-01-01

    Predicted future shifts in the magnitude and frequency (larger but fewer) of precipitation events and enhanced nitrogen (N) deposition may interact to affect grassland productivity, but the effects of N enrichment on the productivity response to individual precipitation events remain unclear. In this study, we quantified the effects of N addition on the response patterns of gross primary productivity (GPP) to individual precipitation events of different sizes (Psize) in a temperate grassland in China. The results showed that N enrichment significantly increased the time-integrated amount of GPP in response to an individual precipitation event (GPPtotal), and the N-induced stimulation of GPP increased with increasing Psize. N enrichment rarely affected the duration of the GPP response, but it significantly stimulated the maximum absolute GPP response. Higher foliar N content might play an important role in the N-induced stimulation of GPP. GPPtotal in both the N-addition and control treatments increased linearly with Psize with similar Psize intercepts (approximately 5 mm, indicating a similar lower Psize threshold to stimulate the GPP response) but had a steeper slope under N addition. Our work indicates that the projected larger precipitation events will stimulate grassland productivity, and this stimulation might be amplified by increasing N deposition. PMID:27264386

  4. Validation of TRMM multi-satellite precipitation analysis (TMPA) products in the Peruvian Andes

    NASA Astrophysics Data System (ADS)

    Mantas, V. M.; Liu, Z.; Caro, C.; Pereira, A. J. S. C.

    2015-09-01

    The relevance of accurate and timely rainfall estimates cannot be overstated. The rainfall gauge network is still insufficient across significant areas worldwide. Rainfall estimates from spaceborne sensors present an opportunity to supplement the existing network and enable the development of critical, near real time applications. However, the societal benefits of such systems can only be realized if the estimates are properly validated and the performance of existing products accurately described. In this study, two products generated by the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) are validated for the Peruvian Andes. This is a region of complex topography that poses significant challenges to the retrieval of rainfall values from space. The TMPA products, both research grade (3B42V7) and near real time (3B42RT), are compared against in situ data. Different observation lengths are studied and the results are analyzed in light of geographic, topographic and climatic constraints. The Time Series of the science grade product were also studied under Dynamic Time Warping and Hierarchical Clustering to streamline inter-tile comparisons. The TMPA products show a good agreement with the gauge values, especially for more prolonged observation periods (over 8 days). The validation results display a strong regional dependence as a consequence of differences in the climate and topography. This region-specific performance calls for additional, detailed case studies and localized validation efforts. Overall the TMPA was found to perform adequately and provide quality information for a number of applications requiring timely estimates in convenient formats.

  5. TRMM-based Merged Data Products Compared to Global Precipitation Climatology Project (GPCP) Analyses

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Huffman, George J.; Bolvin, David; Curtis, Scott

    1999-01-01

    This paper describes recent results of using Tropical Rainfall Measuring Mission (TRMM) (launched in November 1997) information as the key calibration tool; in a merged analysis on a 1 degree x l degree latitude/longitude monthly scale based on multiple satellite sources and raingauge analyses. The TRMM-based product will be compared with the community-based Global Precipitation Climatology Project (GPCP) results. The long-term GPCP analysis is compared to the new TRMM-based analysis which uses the most accurate TRMM information to calibrate the estimates from the Special Sensor Microwave/Imager (SSM/I) and geosynchronous IR observations and merges those estimates together with the TRMM and gauge information to produce accurate rainfall estimates with the increased sampling provided by the combined satellite information. The comparison with TRMM results on a month-to-month basis should clarify the strengths and weaknesses of the long-term GPCP product in the tropics and point to how to improve the monitoring analysis. Preliminary results from the TRMM merged satellite analysis indicates close agreement with the GPCP estimates. By the time of the meeting over a year of TRMM products will be available for comparison. Global tropical and regional values will be compared. Seasonal variations, and variations associated with the 1998 El Nino/Southern Oscillation ENSO event will be examined and compared between the two analyses. These variations will be examined carefully and validated where possible from surface-based radar and gauge observations. The role of TRMM observations in the refinement of the long-term monitoring product will be outlined.

  6. The production and treatment of gaseous pollutants in an electrostatic precipitator

    NASA Technical Reports Server (NTRS)

    Flamm, D. L.; Tangirala, U.

    1977-01-01

    The production of ozone and nitric oxides and the oxidation of two organic contaminants, methane and acetylene, were studied in the corona discharge of a model cylindrical electrostatic precipitator. Both air and oxygen streams were passed through the discharge while current, voltage, electrode/wall radius ratio, residence time and wall temperature were varied. Under all conditions using air, much more ozone was produced in the negative than in the positive corona, in agreement with qualitative data reported in the literature. However, using oxygen, as much as three to four times more ozone is produced by the positive corona. Over a wide range of conditions ozone production is proportional to current. Limited analyses of nitric oxides formation in air indicated that levels were higher in the negative than in the positive corona. In contrast to previous work using an RF discharge, methane contamination was not removed by the corona discharge. However, the oxidation of acetylene was affected by the discharge and could not be accounted for by homogeneous ozonation alone.

  7. TRMM Common Microphysics Products: A Tool for Evaluating Spaceborne Precipitation Retrieval Algorithms

    NASA Technical Reports Server (NTRS)

    Kingsmill, David E.; Yuter, Sandra E.; Hobbs, Peter V.; Rangno, Arthur L.; Heymsfield, Andrew J.; Stith, Jeffrey L.; Bansemer, Aaron; Haggerty, Julie A.; Korolev, Alexei V.

    2004-01-01

    A customized product for analysis of microphysics data collected from aircraft during field campaigns in support of the TRMM program is described. These Common Microphysics Products (CMP's) are designed to aid in evaluation of TRMM spaceborne precipitation retrieval algorithms. Information needed for this purpose (e.g., particle size spectra and habit, liquid and ice water content) was derived using a common processing strategy on the wide variety of microphysical instruments and raw native data formats employed in the field campaigns. The CMP's are organized into an ASCII structure to allow easy access to the data for those less familiar with and without the tools to accomplish microphysical data processing. Detailed examples of the CMP show its potential and some of its limitations. This approach may be a first step toward developing a generalized microphysics format and an associated community-oriented, non-proprietary software package for microphysics data processing, initiatives that would likely broaden community access to and use of microphysics datasets.

  8. Production of crystalline refractory metal oxides containing colloidal metal precipitates and useful as solar-effective absorbers

    DOEpatents

    Narayan, Jagdish; Chen, Yok

    1983-01-01

    This invention is a new process for producing refractory crystalline oxides having improved or unusual properties. The process comprises the steps of forming a doped-metal crystal of the oxide; exposing the doped crystal in a bomb to a reducing atmosphere at superatmospheric pressure and a temperature effecting precipitation of the dopant metal in the crystal lattice of the oxide but insufficient to effect net diffusion of the metal out of the lattice; and then cooling the crystal. Preferably, the cooling step is effected by quenching. The process forms colloidal precipitates of the metal in the oxide lattice. The process may be used, for example, to produce thermally stable black MgO crystalline bodies containing magnetic colloidal precipitates consisting of about 99% Ni. The Ni-containing bodies are solar-selective absorbers, having a room-temperature absorptivity of about 0.96 over virtually all of the solar-energy spectrum and exhibiting an absorption edge in the region of 2 .mu.m. The process parameters can be varied to control the average size of the precipitates. The process can produce a black MgO crystalline body containing colloidal Ni precipitates, some of which have the face-centered-cubic structure and others of which have the body-centered cubic structure. The products of the process are metal-precipitate-containing refractory crystalline oxides which have improved or unique optical, mechanical, magnetic, and/or electronic properties.

  9. Effects of Increased Nitrogen Deposition and Precipitation on Seed and Seedling Production of Potentilla tanacetifolia in a Temperate Steppe Ecosystem

    PubMed Central

    Li, Yang; Yang, Haijun; Xia, Jianyang; Zhang, Wenhao; Wan, Shiqiang; Li, Linghao

    2011-01-01

    Background The responses of plant seeds and seedlings to changing atmospheric nitrogen (N) deposition and precipitation regimes determine plant population dynamics and community composition under global change. Methodology/Principal Findings In a temperate steppe in northern China, seeds of P. tanacetifolia were collected from a field-based experiment with N addition and increased precipitation to measure changes in their traits (production, mass, germination). Seedlings germinated from those seeds were grown in a greenhouse to examine the effects of improved N and water availability in maternal and offspring environments on seedling growth. Maternal N-addition stimulated seed production, but it suppressed seed mass, germination rate and seedling biomass of P. tanacetifolia. Maternal N-addition also enhanced responses of seedlings to N and water addition in the offspring environment. Maternal increased-precipitation stimulated seed production, but it had no effect on seed mass and germination rate. Maternal increased-precipitation enhanced seedling growth when grown under similar conditions, whereas seedling responses to offspring N- and water-addition were suppressed by maternal increased-precipitation. Both offspring N-addition and increased-precipitation stimulated growth of seedlings germinated from seeds collected from the maternal control environment without either N or water addition. Our observations indicate that both maternal and offspring environments can influence seedling growth of P. tanacetifolia with consequent impacts on the future population dynamics of this species in the study area. Conclusion/Significance The findings highlight the importance of the maternal effects on seed and seedling production as well as responses of offspring to changing environmental drivers in mechanistic understanding and projecting of plant population dynamics under global change. PMID:22194863

  10. Convergence of Dynamic Vegetation Net Productivity Responses to Precipitation Variability from 10 Years of MODIS EVI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    According to Global Climate Models (GCMs) the occurrence of extreme events of precipitation will be more frequent in the future. Therefore, important challenges arise regarding climate variability, which are mainly related to the understanding of ecosystem responses to changes in precipitation patte...

  11. MODIS EVI as a Surrogate for Net Primary Production across Precipitation Regimes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    According to Global Climate Models (GCMs) the occurrence of extreme events of precipitation will be more frequent in the future. Therefore, important challenges arise regarding climate variability, which are mainly related to the understanding of ecosystem responses to changes in precipitation patte...

  12. An independent assessment of the monthly PRISM gridded precipitation product in central Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of climate-informed decision support tools for agricultural management requires long-duration location-specific climatologies due to the extreme spatiotemporal variability of precipitation. The traditional source of precipitation data (rain gauges) are too sparsely located to fill t...

  13. Drivers of variation in aboveground net primary productivity and plant community composition differe across a broad precipitation gradient

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has long been a goal of ecology to determine what factors drive variation in aboveground net primary production (ANPP). Total annual precipitation has been shown to be a strong predictor of ANPP across broad spatial scales, but a poor predictor at local scales. Here we aim to determine the amount...

  14. A New Approach for Validating Satellite Estimates of Soil Moisture Using Large-Scale Precipitation: Comparing AMSR-E Products

    NASA Astrophysics Data System (ADS)

    Tuttle, S. E.; Salvucci, G.

    2012-12-01

    Soil moisture influences many hydrological processes in the water and energy cycles, such as runoff generation, groundwater recharge, and evapotranspiration, and thus is important for climate modeling, water resources management, agriculture, and civil engineering. Large-scale estimates of soil moisture are produced almost exclusively from remote sensing, while validation of remotely sensed soil moisture has relied heavily on ground truthing, which is at an inherently smaller scale. Here we present a complementary method to determine the information content in different soil moisture products using only large-scale precipitation data (i.e. without modeling). This study builds on the work of Salvucci [2001], Saleem and Salvucci [2002], and Sun et al. [2011], in which precipitation was conditionally averaged according to soil moisture level, resulting in moisture-outflow curves that estimate the dependence of drainage, runoff, and evapotranspiration on soil moisture (i.e. sigmoidal relations that reflect stressed evapotranspiration for dry soils, roughly constant flux equal to potential evaporation minus capillary rise for moderately dry soils, and rapid drainage for very wet soils). We postulate that high quality satellite estimates of soil moisture, using large-scale precipitation data, will yield similar sigmoidal moisture-outflow curves to those that have been observed at field sites, while poor quality estimates will yield flatter, less informative curves that explain less of the precipitation variability. Following this logic, gridded ¼ degree NLDAS precipitation data were compared to three AMSR-E derived soil moisture products (VUA-NASA, or LPRM [Owe et al., 2001], NSIDC [Njoku et al., 2003], and NSIDC-LSP [Jones & Kimball, 2011]) for a period of nine years (2001-2010) across the contiguous United States. Gaps in the daily soil moisture data were filled using a multiple regression model reliant on past and future soil moisture and precipitation, and soil

  15. The effect of isotopic substitution of deuterium for hydrogen on the morphology of products precipitated from synthetic Bayer solutions

    NASA Astrophysics Data System (ADS)

    Loh, J. S. C.; Watling, H. R.; Parkinson, G. M.

    2002-04-01

    In the production of alumina (Al 2O 3), the precipitation of gibbsite (Al(OH) 3) is the slowest step in the Bayer process. Gibbsite growth rates are generally in the vicinity of microns per hour. Thus, research is focussed on increasing productivity (gibbsite precipitation rates) without compromising product quality. Fundamental to this is an improved understanding of gibbsite growth mechanisms. Isotopic substitution of deuterium for hydrogen in synthetic Bayer (sodium aluminate) solutions was used primarily to investigate deprotonation and reprotonation of the surface hydroxyl groups. Gibbsite precipitates in a highly alkaline solution. The hydroxyl groups situated on the surfaces of the growing crystals are likely to be deprotonated because the pH of the Bayer liquor is >14 and the pK a for the surface protons is in the range of 9-10. The rate of gibbsite growth may therefore depend on the deprotonation and reprotonation of the hydroxyl groups, as the gibbsite crystal lattice consists of hydrogen bonded layers of Al(OH) 3. However, the gibbsite precipitation rates from equivalent sodium aluminate solutions (NaAl(OH) 3 and NaAl(OD) 3) were very similar, indicating that the deprotonation and reprotonation of the hydroxyl groups are not rate-limiting. Nonetheless, the isotopic substitution of deuterium for hydrogen in synthetic Bayer solutions did have effects on the gibbsite solubility, crystallization growth process, product phase and morphology. This paper focuses on the changes in product morphology. Isotopic substitution resulted in changes in the orientation of nuclei formed on seed surfaces as well as the nuclei morphology. This is the first time that isotopic substitution has been used to investigate gibbsite precipitation in synthetic Bayer solutions.

  16. Geochemical modeling of the influence of silicate mineral alteration on alkalinity production and carbonate precipitation

    NASA Astrophysics Data System (ADS)

    Herda, Gerhard; Kraemer, Stephan M.; Gier, Susanne; Meister, Patrick

    2016-04-01

    High CO2 partial pressure (pCO2) in deep rock reservoirs causes acidification of the porefluid. Such conditions occur during injection and subsurface storage of CO2 (to prevent the release of greenhouse gas) but also naturally in zones of strong methanogenic microbial activity in organic matter-rich ocean margin sediments. The acidic fluids are corrosive to carbonates and bear the risk of leakage of CO2 gas to the surface. Porefluid acidification may be moderated by processes that increase the alkalinity, i.e. that produce weak acid anions capable of buffering the acidification imposed by the CO2. Often, alkalinity increases as a result of anaerobic microbial activity, such as anaerobic oxidation of methane. However, on a long term the alteration of silicates, in particular, clay minerals, may be a more efficient mechanism of alkalinity production. Under altered temperature, pressure and porefluid composition at depth, clay minerals may change to thermodynamically more stable states, thereby increasing the alkalinity of the porefluid by partial leaching of Mg-(OH)2 and Ca-(OH)2 (e.g. Wallmann et al., 2008; Mavromatis et al., 2014). This alteration may even be enhanced by a high pCO2. Thus, silicate alteration can be essential for a long-term stabilization of volatile CO2 in the form of bicarbonate or may even induce precipitation of carbonate minerals, but these processes are not fully understood yet. The goal of this study is to simulate the alkalinity effect of silicate alteration under diagenetic conditions and high pCO2 by geochemical modeling. We are using the program PHREEQC (Parkhurst and Appelo, 2013) to generate high rock/fluid ratio characteristics for deep subsurface rock reservoirs. Since we are interested in the long-term evolution of diagenetic processes, over millions of years, we do not consider kinetics but calculate the theoretically possible equilibrium conditions. In a first step we are calculating the saturation state of different clay minerals

  17. Validation of satellite precipitation product GSMaP/NRT with ground rain gauges in Cambodia

    NASA Astrophysics Data System (ADS)

    Tsujimoto, Kumiko; Ohta, Tetsu; Koike, Toshio

    2014-05-01

    The Global Satellite Mapping of Precipitation Near Real Time data (GSMaP/NRT) is one of the satellite precipitation datasets which is produced by Japan Aerospace Exploration Agency with time resolution of 1 hour and spatial resolution of 0.1 degrees. Since it is published approximately 4 hours after the observation, it is expected to contribute to the early warning of floods and water resource management in developing countries as well which have poor ground observation network. Our target area, Cambodia in the Indochina Peninsula, is one of such countries. However, there had been few ground rain gauges so that it had been impossible to validate GSMaP/NRT. Thus, the accuracy of GSMaP/NRT in this area had been unclear. One of the major characteristics of this area is that it has a vast lake area with water surface temperature of more than 30 degrees all year round. With this lake surface, it has been relieved that a unique local atmospheric circulation and its associated precipitation occur in this area. In order to validate the rainfall amount in this area, we rehabilitated and newly installed rain gauges. As a result, we have 34 automatic rain-gauges now and data is available from September 2009. Using this data as well as hourly rainfall amount from GSMaP/NRT and brightness temperature (TB) from Multi-functional Transport Satellite Infrared 1 channel (MTSAT/IR1), we analyzed the error tendency of the GSMaP/NRT product. The analysis showed that the relationship between rain gauges and GSMaP/NRT were very poor. Especially, strong rainfall events in full-monsoon season over land with 208K < TB < 253K and those in post-monsoon season over the lake with TB < 208K were very much underestimated by GSMaP/NRT. The results suggest that it is still difficult to use GSMaP/NRT data for hydrological applications to get soil moisture distribution and river discharge in this area, especially at small river basins. In addition, although many rainfall events were produced by GSMa

  18. Examination of the jarosite-alunite precipitate addition in the raw meal for the production of sulfoaluminate cement clinker.

    PubMed

    Katsioti, M; Tsakiridis, P E; Leonardou-Agatzini, S; Oustadakis, P

    2006-04-17

    The aim of the present research work was to investigate the possibility of adding a jarosite-alunite chemical precipitate, a waste product of a new hydrometallurgical process developed to treat economically low-grade nickel oxides ores, in the raw meal for the production of sulfoaluminate cement clinker. For that reason, two samples of raw meals were prepared, one contained 20% gypsum, as a reference sample ((SAC)Ref) and another with 11.31% jarosite-alunite precipitate ((SAC)J/A). Both raw meals were sintered at 1300 degrees C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the jarosite-alunite precipitate did not affect the mineralogical characteristics of the so produced sulfoaluminate cement clinker and there was confirmed the formation of the sulfoaluminate phase (C4A3S), the most typical phase of this cement type. Furthermore, both clinkers were tested by determining the grindability, setting time, compressive strength and expansibility. The hydration products were examined by XRD analysis at 2, 7, 28 and 90 days. The results of the physico-mechanical tests showed that the addition of jarosite-alunite precipitate did not negatively affect the quality of the produced cement. PMID:16223566

  19. Precipitation Analysis at Fine Time Scales using TRMM and Other Satellites: Real-time and Research Products and Applications

    NASA Technical Reports Server (NTRS)

    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.

  20. Precipitation Analysis at Fine Time Scales using TRMM and Other Satellites: Realtime and Research Products and Applications

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Huffman, George; Bolvin, David; Nelkin, Eric; Curtis, Scott; Pierce, Harold; Gu, Guojon

    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 deg latitude-longitude resolution over the latitude range from 50 deg N-50 deg 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, 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.

  1. Precipitation Analysis at Fine Time Scales Using Multiple Satellites: Real-time and Research Products and Applications

    NASA Technical Reports Server (NTRS)

    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.

  2. Convergence and contingency in production-precipitation relationships in North American and South African C4 grasslands.

    PubMed

    Knapp, Alan K; Burns, Catherine E; Fynn, Richard W S; Kirkman, Kevin P; Morris, Craig D; Smith, Melinda D

    2006-09-01

    Mesic grasslands in North America and South Africa share many structural attributes, but less is known of their functional similarities. We assessed the control of a key ecosystem process, aboveground net primary production (ANPP), by interannual variation in precipitation amount and pattern via analysis of data sets (15- and 24-year periods) from long-term research programs on each continent. Both sites were dominated by C(4) grasses and had similar growing season climates; thus, we expected convergence in precipitation-ANPP relationships. Lack of convergence, however, would support an alternative hypothesis-that differences in evolutionary history and purportedly greater climatic variability in South Africa fundamentally alter the functioning of southern versus northern hemisphere grasslands. Neither mean annual precipitation nor mean ANPP differed between the South African and North American sites (838 vs. 857 mm/year, 423.5 vs. 461.4 g/m(2) respectively) and growing season precipitation-ANPP relationships were similar. Despite overall convergence, there were differences between sites in how the seasonal timing of precipitation affected ANPP. In particular, interannual variability in precipitation that fell during the first half of the growing season strongly affected annual ANPP in South Africa (P < 0.01), but was not related to ANPP in North America (P = 0.098). Both sites were affected similarly by late season precipitation. Divergence in the seasonal course of available soil moisture (chronically low in the winter and early spring in the South African site vs. high in the North American site) is proposed as a key contingent factor explaining differential sensitivity in ANPP to early season precipitation in these two grasslands. These long-term data sets provided no support for greater rainfall, temperature or ANPP variability in the South African versus the North American site. However, greater sensitivity of ANPP to early season precipitation in the South

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

    NASA Astrophysics Data System (ADS)

    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

  4. Effect of Co-solutes on the Products and Solubility of Uranium(VI) Precipitated with Phosphate

    SciTech Connect

    Mehta, Vrajesh; Maillot, Fabien; Wang, Zheming; Catalano, Jeffrey G.; Giammar, Daniel E.

    2014-01-22

    Uranyl phosphate solids are often found with uranium ores, and their low solubility makes them promising target phases for in situ remediation of uranium-contaminated subsurface environments. The products and solubility of uranium(VI) precipitated with phosphate can be affected by the pH, dissolved inorganic carbon (DIC) concentration, and co-solute composition (e.g. Na+/Ca2+) of the groundwater. Batch experiments were performed to study the effect of these parameters on the products and extent of uranium precipitation induced by phosphate addition. In the absence of co-solute cations, chernikovite [H3O(UO2)(PO4)•3H2O] precipitated despite uranyl orthophosphate [(UO2)3(PO4)2•4H2O] being thermodynamically more favorable under certain conditions. As determined using X-ray diffraction, electron microscopy, and laser induced fluorescence spectroscopy, the presence of Na+ or Ca2+ as a co-solute led to the precipitation of sodium autunite ([Na2(UO2)2(PO4)2] and autunite [Ca(UO2)2(PO4)2]), which are structurally similar to chernikovite. In the presence of sodium, the dissolved U(VI) concentrations were generally in agreement with equilibrium predictions of sodium autunite solubility. However, in the calcium-containing systems, the observed concentrations were below the predicted solubility of autunite, suggesting the possibility of uranium adsorption to or incorporation in a calcium phosphate precipitate in addition to the precipitation of autunite.

  5. A new Grid Product of Tropical Cyclone Precipitation (TCP) for North America from 1930 to 2013

    NASA Astrophysics Data System (ADS)

    Zhu, L.

    2015-12-01

    We first developed a new method that collects daily TCP by using historical storm tracks and precipitation observation based on daily rain gauges in both U.S. and Mexico and calibrated it with satellite precipitation observation. We used a parametrized wind field to correct the possible under-estimations of precipitation in rain gauges. Grid interpolation parameters were optimized by testing different historical rain gauge densities and comparing our grid estimation of TCP and the observation from TRMM Multi-satellite Precipitation Analysis (3B42) by for the data available period from 1998 to 2013. The calibrated method was then used for the whole 94 years of TCP estimation. The preliminary result shows that the frequency of TCP events does not have significant change but the TCP intensity has significant increasing trends, especially in certain locations in North Carolina and Yucatan Peninsula in Mexico. This new long term TCP climatology can potentially assist model calibration and disaster prevention/mitigation.

  6. Long-Term Historical Rainfall-Runoff Modeling Using High-Resolution Satellite-based Precipitation Products

    NASA Astrophysics Data System (ADS)

    Ashouri, H.; Nguyen, P.; Thorstensen, A. R.; Hsu, K. L.; Sorooshian, S.

    2014-12-01

    This study evaluates the performance of a newly developed long-term high-resolution satellite-based precipitation products, named Precipitation Estimation from Remotely Sensed Information using Artificial Neural Network - Climate Data Record (PERSIANN-CDR), in hydrological modeling. PERSIANN-CDR estimations are biased corrected using GPCP monthly climatology data. PERSIANN-CDR provides daily rainfall estimates at 0.25° x 0.25° grid boxes for 1983-2014 (delayed present). This newly released product makes it feasible to model the streamflow over the past 30 years. Three test basins from the Distributed Hydrologic Model Intercomparison Project - Phase 2 (DMIP 2) are chosen. Comparing with other satellite products, the Version 7 TRMM Multi-satellite Precipitation Analysis (TMPA) product is used. Stage IV radar data is used as a reference data for evaluating the PERSIANN-CDR and TMPA precipitation data. All products are scaled to 0.25° and daily spatiotemporal resolution. The study is performed in two phases. In the first phase, the 2003-2011 period where all the products are available is chosen. Precipitation evaluation results, presented on Taylor Diagrams, show that TMPA and PERSIANN-CDR have close performances. The National Weather Service (NWS) Office of Hydrologic Development (OHD) Hydrology Laboratory-Research Distributed Hydrologic Model (HL-RDHM) is then forced with the PERSIANN-CDR and the TMPA precipitation products, as well as the stage IV radar data. USGS Streamflow observations at the outlet of the basins are used as the reference streamflow data. The results show that in general, in all the three DMIP 2 basins the simulated hydrographs forced with PERSIANN-CDR and TMPA show good agreement, as the statistical measures such as root mean square error, bias, and correlation coefficient are close. In addition, with respect to the streamflow peaks, PERSIANN-CDR shows better performance than Stage IV radar data in capturing the extreme streamflow magnitudes

  7. Development and evaluation of climatologically-downscaled AFWA AGRMET precipitation products over the continental U.S.

    NASA Astrophysics Data System (ADS)

    Garcia, M.; Peters-Lidard, C. D.; Eylander, J. B.; Daly, C.; Gibson, W.; Tian, Y.; Zeng, J.; Kato, H.

    2008-05-01

    Collaborations between the Air Force Weather Agency (AFWA), the Hydrological Sciences Branch at NASA-GSFC, and the PRISM Group at Oregon State University have led to improvements in the processing of meteorological forcing inputs for the NASA-GSFC Land Information System (LIS; Kumar et al. 2006), a sophisticated framework for LSM operation and model coupling experiments. Efforts at AFWA toward the production of surface hydrometeorological products are currently in transition from the legacy Agricultural Meteorology modeling system (AGRMET) to use of the LIS framework and procedures. Recent enhancements to meteorological input processing for application to land surface models in LIS include the assimilation of climate-based information for the spatial interpolation and downscaling of precipitation fields. Climatological information included in the LIS- based downscaling procedure for North America is provided by a monthly high-resolution PRISM (Daly et al. 1994, 2002; Daly 2006) dataset based on a 30-year analysis period. The combination of these sources and methods attempts to address the strengths and weaknesses of available legacy products, objective interpolation methods, and the PRISM knowledge-based methodology. All of these efforts are oriented on an operational need for timely estimation of spatial precipitation fields at adequate spatial resolution for customer dissemination and near-real-time simulations in regions of interest. This work focuses on value added to the AGRMET precipitation product by the inclusion of high-quality climatological information on a monthly time scale. The AGRMET method uses microwave-based satellite precipitation estimates from various polar-orbiting platforms (NOAA POES and DMSP), infrared-based estimates from geostationary platforms (GOES, METEOSAT, etc.), related cloud analysis products, and surface gauge observations in a complex and hierarchical blending process. Results from processing of the legacy AGRMET precipitation

  8. Improving the accuracy of MODIS 8-day snow products with in situ temperature and precipitation data

    NASA Astrophysics Data System (ADS)

    Dong, Chunyu; Menzel, Lucas

    2016-03-01

    MODIS snow data are appropriate for a wide range of eco-hydrological studies and applications in the fields of snow-related hazards, early warning systems and water resources management. However, the high spatio-temporal resolution of the remotely sensed data is often biased by snow misclassifications, and cloud cover frequently limits the availability of the MODIS-based snow cover information. In this study, we applied a four-step methodology that aims to optimize the accuracy of MODIS snow data. To reduce the cloud fraction, 8-day MODIS data from both the Aqua and Terra satellites were combined. Neighborhood analysis was applied as well for this purpose, and it also contributed to the retrieval of some omitted snow. Two meteorological filters were then applied to combine information from station-based measurements of minimum ground temperature, precipitation and air temperature. This procedure helped to reduce the overestimation of snow cover. To test this technique, the methodology was applied to the Rhineland-Palatinate region in southwestern Germany (approximately 20,000 km2), where cloud cover is especially high during winter and surface heterogeneity is complex. The results show that mean annual cloud coverage (reference period 2002-2013) of the 8-day MODIS snow maps could be reduced using this methodology from approximately 14% to 4.5%. During the snow season, obstruction by clouds could be reduced by even a higher degree, but still remains at about 11%. Further, the overall snow overestimation declined from 11.0-11.9% (using the original Aqua-Terra data) to 1.0-1.5%. The method is able to improve the overall accuracy of the 8-day MODIS snow product from originally 78% to 89% and even to 93% during cloud free periods.

  9. Quantifying discharge uncertainty from remotely sensed precipitation data products in Puerto Rico

    NASA Astrophysics Data System (ADS)

    Weerasinghe, H.; Raoufi, R.; Yoon, Y.; Beighley, E., II; Alshawabkeh, A.

    2014-12-01

    Preterm birth is a serious health issue in the United States that contributes to over one-third of all infant deaths. Puerto Rico being one of the hot spots, preliminary research found that the high preterm birth rate can be associated with exposure to some contaminants in water used on daily basis. Puerto Rico has more than 200 contaminated sites including 16 active Superfund sites. Risk of exposure to contaminants is aggravated by unlined landfills lying over the karst regions, highly mobile and dynamic nature of the karst aquifers, and direct contact with surface water through sinkholes and springs. Much of the population in the island is getting water from natural springs or artesian wells that are connected with many of these potentially contaminated karst aquifers. Mobility of contaminants through surface water flows and reservoirs are largely known and are highly correlated with the variations in hydrologic events and conditions. In this study, we quantify the spatial and temporal distribution of Puerto Rico's surface water stores and fluxes to better understand potential impacts on the distribution of groundwater contamination. To quantify and characterize Puerto Rico's surface waters, hydrologic modeling, remote sensing and field measurements are combined. Streamflow measurements are available from 27 U.S. Geological Survey (USGS) gauging stations with drainage areas ranging from 2 to 510 km2. Hillslope River Routing (HRR) model is used to simulate hourly streamflow from watersheds larger than 1 km2 that discharge to ocean. HRR model simulates vertical water balance, lateral surface and subsurface runoff and river discharge. The model consists of 4418 sub-catchments with a mean model unit area (i.e., sub-catchment) of 1.8 km2. Using gauged streamflow measurements for validation, we first assess model results for simulated discharge using three precipitation products: TRMM-3B42 (3 hour temporal resolution, 0.25 degree spatial resolution); NWS stage

  10. Evaluation of atmospheric precipitable water from reanalysis products using homogenized radiosonde observations over China

    NASA Astrophysics Data System (ADS)

    Zhao, Tianbao; Wang, Juanhuai; Dai, Aiguo

    2015-10-01

    Many multidecadal atmospheric reanalysis products are available now, but their consistencies and reliability are far from perfect. In this study, atmospheric precipitable water (PW) from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR), NCEP/Department of Energy (DOE), Modern Era Retrospective-Analysis for Research and Applications (MERRA), Japanese 55 year Reanalysis (JRA-55), JRA-25, ERA-Interim, ERA-40, Climate Forecast System Reanalysis (CFSR), and 20th Century Reanalysis version 2 is evaluated against homogenized radiosonde observations over China during 1979-2012 (1979-2001 for ERA-40). Results suggest that the PW biases in the reanalyses are within ˜20% for most of northern and eastern China, but the reanalyses underestimate the observed PW by 20%-40% over western China and by ˜60% over the southwestern Tibetan Plateau. The newer-generation reanalyses (e.g., JRA25, JRA55, CFSR, and ERA-Interim) have smaller root-mean-square error than the older-generation ones (NCEP/NCAR, NCEP/DOE, and ERA-40). Most of the reanalyses reproduce well the observed PW climatology and interannual variations over China. However, few reanalyses capture the observed long-term PW changes, primarily because they show spurious wet biases before about 2002. This deficiency results mainly from the discontinuities contained in reanalysis relative humidity fields in the middle-lower troposphere due to the wet bias in older radiosonde records that are assimilated into the reanalyses. An empirical orthogonal function (EOF) analysis revealed two leading modes that represent the long-term PW changes and El Niño-Southern Oscillation-related interannual variations with robust spatial patterns. The reanalysis products, especially the MERRA and JRA-25, roughly capture these EOF modes, which account for over 50% of the total variance. The results show that even during the post-1979 satellite era, discontinuities in radiosonde data can still

  11. Precipitation and Topography as Drivers of Tree Water Use and Productivity at Multiple Scales

    NASA Astrophysics Data System (ADS)

    Martin, J. T.; Hu, J.; Looker, N. T.; Jencso, K. G.

    2014-12-01

    Water is commonly the primary limiting factor for tree growth in semi-arid regions of the Western U.S. and tree productivity can vary drastically across landscapes as a function of water availability. The role of topography as a first order control on soil and ground water has been well studied; however, the strategies trees use to cope with water limitation in different landscape positions and across time remain unclear. As growing seasons progress, the availability of water changes temporally, as water inputs transition from snowmelt to rainfall, and spatially, as divergent positions dry more than convergent ones. We seek to understand how the interaction of these processes dictate where trees access water and which strategies most successfully avert water limitation of growth. We take advantage of clear differences in the isotopic signatures of snow and summer rain to track water utilized by Douglas fir, Ponderosa pine, Subalpine fir, Engelmann spruce, and Western larch in both convergent and divergent landscape positions and across time. We couple these data with evidence of growth limitation inferred from reductions in lateral growth rates observed by continuous dendrometer measurements to link tree water use and productivity. Xylem waters reflect both the precipitation type and soil profile distribution of water used by trees for growth and dendrometer measurements reflect the effects of water limitation through changes in the lateral growth curve as soil moistures decline. Isotope signatures from rain, snow and stream water fell predictably along the local meteoric water line with values from xylem samples falling between those of rain and snow. Trees on southern aspects exhibit more growth limitation in divergent than convergent positions while this effect appears muted or non-existent on northern aspects. Trees in convergent hollow positions rely more on snow water while trees on slopes utilize more rain water. Surprisingly, trees at lower elevation rely

  12. Nickel sulfide formation at low temperature: initial precipitates, solubility and transformation products

    EPA Science Inventory

    The formation of nickel sulfides has been examined experimentally over the temperature range from 25 to 60°C. At all conditions studied, hexagonal (α-NiS) was the initial precipitate from solution containing Ni2+ and dissolved sulfide. The formation of millerite (β- NiS, rhombo...

  13. MWRRET Value-Added Product: The Retrieval of Liquid Water Path and Precipitable Water Vapor from Microwave Radiometer (MWR) Datasets

    SciTech Connect

    KL Gaustad; DD Turner

    2007-09-30

    This report provides a short description of the Atmospheric Radiation Measurement (ARM) microwave radiometer (MWR) RETrievel (MWRRET) Value-Added Product (VAP) algorithm. This algorithm utilizes complimentary physical and statistical retrieval methods and applies brightness temperature offsets to reduce spurious liquid water path (LWP) bias in clear skies resulting in significantly improved precipitable water vapor (PWV) and LWP retrievals. We present a general overview of the technique, input parameters, output products, and describe data quality checks. A more complete discussion of the theory and results is given in Turner et al. (2007b).

  14. Effects of Reduced Summer Precipitation on Productivity and Forage Quality of Floodplain Meadows at the Elbe and the Rhine River

    PubMed Central

    Ludewig, Kristin; Donath, Tobias W.; Zelle, Bianka; Eckstein, R. Lutz; Mosner, Eva; Otte, Annette; Jensen, Kai

    2015-01-01

    Background Floodplain meadows along rivers are semi-natural habitats and depend on regular land use. When used non-intensively, they offer suitable habitats for many plant species including rare ones. Floodplains are hydrologically dynamic ecosystems with both periods of flooding and of dry conditions. In German floodplains, dry periods may increase due to reduced summer precipitation as projected by climate change scenarios. Against this background, the question arises, how the forage quantity and quality of these meadows might change in future. Methods We report results of two field trials that investigated effects of experimentally reduced summer precipitation on hay quantity and quality of floodplain meadows at the Rhine River (2011-2012) and at two Elbe tributaries (2009-2011). We measured annual yield, the amount of hay biomass, and contents of crude protein, crude fibre, energy, fructan, nitrogen, phosphorus, and potassium. Results The annual yield decreased under precipitation reduction at the Rhine River. This was due to reduced productivity in the second cut hay at the Rhine River in which, interestingly, the contents of nitrogen and crude protein increased. The first cut at the Rhine River was unaffected by the treatments. At the Elbe tributaries, the annual yield and the hay quantity and quality of both cuts were only marginally affected by the treatments. Conclusion We conclude that the yield of floodplain meadows may become less reliable in future since the annual yield decreased under precipitation reduction at the Rhine River. However, the first and agriculturally more important cut was almost unaffected by the precipitation reduction, which is probably due to sufficient soil moisture from winter/spring. As long as future water levels of the rivers will not decrease during spring, at least the use of the hay from the first cut of floodplain meadows appears reliable under climate change. PMID:25950730

  15. Sensitivity of seasonal weather prediction and extreme precipitation events to soil moisture initialization uncertainty using SMOS soil moisture products

    NASA Astrophysics Data System (ADS)

    Khodayar-Pardo, Samiro; Lopez-Baeza, Ernesto; Coll Pajaron, M. Amparo

    Sensitivity of seasonal weather prediction and extreme precipitation events to soil moisture initialization uncertainty using SMOS soil moisture products (1) S. Khodayar, (2) A. Coll, (2) E. Lopez-Baeza (1) Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology (KIT), Karlsruhe Germany (2) University of Valencia. Earth Physics and Thermodynamics Department. Climatology from Satellites Group Soil moisture is an important variable in agriculture, hydrology, meteorology and related disciplines. Despite its importance, it is complicated to obtain an appropriate representation of this variable, mainly because of its high temporal and spatial variability. SVAT (Soil-Vegetation-Atmosphere-Transfer) models can be used to simulate the temporal behaviour and spatial distribution of soil moisture in a given area and/or state of the art products such as the soil moisture measurements from the SMOS (Soil Moisture and Ocean Salinity) space mission may be also convenient. The potential role of soil moisture initialization and associated uncertainty in numerical weather prediction is illustrated in this study through sensitivity numerical experiments using the SVAT SURFEX model and the non-hydrostatic COSMO model. The aim of this investigation is twofold, (a) to demonstrate the sensitivity of model simulations of convective precipitation to soil moisture initial uncertainty, as well as the impact on the representation of extreme precipitation events, and (b) to assess the usefulness of SMOS soil moisture products to improve the simulation of water cycle components and heavy precipitation events. Simulated soil moisture and precipitation fields are compared with observations and with level-1(~1km), level-2(~15 km) and level-3(~35 km) soil moisture maps generated from SMOS over the Iberian Peninsula, the SMOS validation area (50 km x 50 km, eastern Spain) and selected stations, where in situ measurements are available covering different vegetation cover

  16. Primary Productivity and Precipitation Use Efficiency in Mixed-Grass Prairie: A Comparison of Northern and Southern U.S. Sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precipitation is a primary determinant of terrestrial ecosystem structure and function and as such, precipitation-use efficiency (PUE) is a key determinant of aboveground net primary production (ANPP). We used 76 datasets to contrast ANPP and PUE estimates between northern (southeast Montana) and s...

  17. Identifying false rain in satellite precipitation products using CloudSat and MODIS

    NASA Astrophysics Data System (ADS)

    Nasrollahi, N.; Hsu, K.; Sorooshian, S.

    2012-12-01

    Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on board NASA Earth Observing System Aqua and Terra platform with 36 spectral bands provides valuable information about cloud microphysical characteristics. Additionally, CloudSat, selected as a NASA Earth Sciences Systems Pathfinder (ESSP) satellite mission, is designed to measure vertical structure of clouds. The CloudSat radar flies in formation with Aqua with only an average of 60 second delay. In this study, the application of MODIS multispectral images and CloudSat Level 2-C Precipitation Column Algorithm in false rain identification is investigated. Using a machine learning technique, the presence of precipitation will be assigned to textural and spectral features of clouds observed by the MODIS satellite, whenever CloudSat surface rainfall retrieval is available. This information for different regions and seasons create a training data set. The training database will then be used as a reference to find if any pixel in the MODIS retrieval window is falsely identified as rainy pixel for the times that CloudSat data is not available. The input to the Artificial Neural Networks (ANN) model is a combination of 8 MODIS visible, water vapor and infrared channels. The performance of model with combination of different MODIS channels is estimated. The results of ANN model are used to filter out false rainy pixels from satellite precipitation estimates (e.g. PERSIANN). The outcome of the new corrected precipitation data is compared to ground based radar measurements (Stage IV radar data). The results show a 64 percent reduction in false rain in PERSIANN satellite data for 100 cases investigated in summer 2008 and 24 percent false rain reduction in more than 50 cases studied in winter 2010.

  18. A Rapid Protoyping Approach for the Evaluation of Potential GPM-Era Precipitation Products for Water Resources Management Applications

    NASA Astrophysics Data System (ADS)

    Anantharaj, V. G.; Houser, P. R.; Turk, F. J.; Peterson, C. A.; Hossain, F.; Moorhead, R. J.; Toll, D. L.; Mostovoy, G.

    2009-04-01

    societal benefits related to human health (soil moisture, climate and disease outbreak), homeland security (removal of chemical/biological/nuclear agents), flooding potential and warning, water availability, water quality, and agriculture and food security. In 2006, the NASA ASP sponsored two RPC experiments to evaluate potential GPM-era high resolution satellite precipitation products for water management applications. One of the current uncertainties involved in the GPM missions is the nature of the exact configuration of the constellations of satellites and hence the potential for the dynamic error characteristics over time of the precipitation estimates. For the RPC evaluations, we needed a satellite precipitation product that would be analogous to the GPM-era products. Our solution was to develop a suite of high resolution precipitation products, based on the NRL-Blend algorithm. We created a set of 10 different satellite precipitation estimates (hereafter referred to as the "GPM-proxy data"), using the currently available IR and microwave sensors. However, in each product we systematically left out sets of observations and/or sensors, such as AM orbits. The geographical focus of our study was the operational domain of the Arkansas Basin River Forecast Center (ABRFC) of the U.S. National Weather Service. We have evaluated the GPM-proxy data against the operational product (radar and gauge based) used by ABRFC. Further, we also performed a set of soil water content (SWC) sensitivity experiments using the Noah and Mosaic Land Surface Models (LSM) to quantify the impacts on water management applications involving land surface hydrology. Both the LSMs were forced with the same set of GPM-proxy data. Though the overall spatial patterns for both the models were similar, there were subtle differences in the respective model sensitivities to the different precipitation forcings. These experimental results illustrate the need for comprehensive pre-evaluations of applications

  19. Error analysis of global satellite precipitation products using daily gauged observations over the upper central Blue Nile Basin

    NASA Astrophysics Data System (ADS)

    Sahlu, Dejene; Moges, Semu; Anagnostou, Emmanouil N.; Hailu, Dereje

    2015-04-01

    Water resource assessment, planning and management in Africa are often constrained due to lack of reliable spatio-temporal rainfall data. Satellite and global reanalysis products are steadily growing and offering useful alternative datasets of rainfall globally. Aim of this paper is to examine the error characteristics of the main available global satellite precipitation products with the view to improve the reliability of wet season (June to September) rainfall datasets over the upper Blue Nile Basin in Ethiopia. The study utilized six satellite derived precipitation datasets at 0.25-deg spatial grid size and daily temporal resolution:1) the near real-time (3B42_RT) and gauge adjusted (3B42_V7) products of Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA), 2) gauge adjusted and unadjusted Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) products and 3) the gauge adjusted and un-adjusted product of the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center Morphing technique (CMORPH) over the period of 2000 to 2013. The historical daily rainfall data sets are chosen for the same period from 64 gauging stations which are within a mountainous area of about 45,000 km2. The elevation of gauges used in this error study ranged from 1800 to 3000 meters above sea level. The error analysis utilized statistical techniques of missed rainfall volume fraction (MRV), falsely detected rainfall volume fraction (FRV), mean relative error (MRE), bias ratio (Bias), coefficient of variation of error (CVE) and the trends of the error metrics with respect to elevation. The three error metrics, MRE, Bias and CVE are further examined for five rainfall thresholds associated with different percentile categories (2nd, 20th, 50th, 80th and 98th) . Results show that CMORPH has relatively lower MRV (~1.5 %) than the TRMM and PERSIANN products (10 -13 %.). Non-gauge adjusted

  20. Combined effects of precipitation and nitrogen deposition on native and invasive winter annual production in California deserts.

    PubMed

    Rao, Leela E; Allen, Edith B

    2010-04-01

    Primary production in deserts is limited by soil moisture and N availability, and thus is likely to be influenced by both anthropogenic N deposition and precipitation regimes altered as a consequence of climate change. Invasive annual grasses are particularly responsive to increases in N and water availabilities, which may result in competition with native forb communities. Additionally, conditions favoring increased invasive grass production in arid and semi-arid regions can increase fire risk, negatively impacting woody vegetation that is not adapted to fire. We conducted a seeded garden experiment and a 5-year field fertilization experiment to investigate how winter annual production is altered by increasing N supply under a range of water availabilities. The greatest production of invasive grasses and native forbs in the garden experiment occurred under the highest soil N (inorganic N after fertilization = 2.99 g m(-2)) and highest watering regime, indicating these species are limited by both water and N. A classification and regression tree (CART) analysis on the multi-year field fertilization study showed that winter annual biomass was primarily limited by November-December precipitation. Biomass exceeded the threshold capable of carrying fire when inorganic soil N availability was at least 3.2 g m(-2) in piñon-juniper woodland. Due to water limitation in creosote bush scrub, biomass exceeded the fire threshold only under very wet conditions regardless of soil N status. The CART analyses also revealed that percent cover of invasive grasses and native forbs is primarily dependent on the timing and amount of precipitation and secondarily dependent on soil N and site-specific characteristics. In total, our results indicate that areas of high N deposition will be susceptible to grass invasion, particularly in wet years, potentially reducing native species cover and increasing the risk of fire. PMID:19967416

  1. Production and characterization of poly(3-hydroxybutyrate) generated by Alcaligenes latus using lactose and whey after acid protein precipitation process.

    PubMed

    Berwig, Karina Hammel; Baldasso, Camila; Dettmer, Aline

    2016-10-01

    Whey after acid protein precipitation was used as substrate for PHB production in orbital shaker using Alcaligenes latus. Statistical analysis determined the most appropriate hydroxide for pH neutralization of whey after protein precipitation among NH4OH, KOH and NaOH 10%w/v. The results were compared to those of commercial lactose. A scale-up test in a 4L bioreactor was done at 35°C, 750rpm, 7L/min air flow, and 6.5 pH. The PHB was characterized through Fourier Transform Infrared Spectroscopy, thermogravimetry and differential scanning calorimetry. NH4OH provided the best results for productivity (p), 0.11g/L.h, and for polymer yield, (YP/S), 1.08g/g. The bioreactor experiment resulted in lower p and YP/S. PHB showed maximum degradation temperature (291°C), melting temperature (169°C), and chemical properties similar to those of standard PHB. The use of whey as a substrate for PHB production did not affect significantly the final product quality. PMID:27347795

  2. Global Assessment of Dryland Degradation Using Long-Term Earth Observation Data Sets of Precipitation and Vegetation Productivity

    NASA Astrophysics Data System (ADS)

    Horion, S.; Fensholt, R.; Verbesselt, J.; Tagesson, T.; Rasmussen, K.

    2013-12-01

    Continuous time series of high quality Earth Observation (EO) based estimates of vegetation are key information for the assessment of long-term degradation in ecosystem function and productivity. In arid and semi-arid areas it has been reported that land degradation (LD) affects the well-being of 250 million people worldwide, which places it among today's most pressing environmental issues. However scientifically robust methods for assessing land degradation at global scale are still lacking. Indeed LD processes are complex and driven by multiple factors, either natural (e.g. changes in climate variability) or anthropic (eg. over-/mis- use of land resources), those factors often being region dependent. Traditionally LD assessment methods are based on the postulate that water availability is the major climate determinant for plant growth and production in drylands. Relationships between precipitation and above-ground net primary productivity (ANPP) have been extensively studied to better understand the impact of climate variability on dryland vegetation productivity. Besides it has been claimed that the ratio ANPP to precipitation, known as the Rain-Use Efficiency (RUE), is a conservative property of the vegetation cover in drylands if the vegetation cover is not subject to non-precipitation related LD; and therefore change in RUE could inform on human-induced degradation. However several authors have put forward the many limitations of RUE and gave recommendations for a proper use of this concept (e.g. Fensholt et al. 2013, Prince et al. 2007). Fensholt et al. (2013) notably recommend to restrict its use to areas where a linear relationship between rainfall and the selected EO based proxy for ANPP is found and where the regression offset of this relationship is close to zero. In this study the concept of RUE as indicator of human-induced LD in drylands will be evaluated at global scale. Both long-term trends and abrupt changes in RUE time series will be analyzed

  3. Comparison of products from ERA-40, NCEP-2, and CRU with station data for summer precipitation over China

    NASA Astrophysics Data System (ADS)

    Zhao, T. B.; Fu, C. B.

    2006-07-01

    Summer precipitation products from the 45-Year European Centre for Weather Forecast (ECTMWF) Reanalysis (ERA-40), and NCEP-Department of Energy (DOE) Atmospheric Model Intercomparison Project (ATMIP-II) Reanalysis (NCEP-2), and Climatic Research Unit (CRU) TS 2.1 dataset are compared with the corresponding observations over China in order to understand the quality, and utility of the reanalysis datasets for the period 1979-2001. The results reveal that although the magnitude and location of the rainfall belts differ among the reanalysis, CRU, and station data over South and West China, the spatial distributions show good agreement over most areas of China. In comparison with the observations in most areas of China, CRU best matches the observed summer precipitation, while ERA-40 reports less precipitation and NCEP-2 reports more precipitation than the observations. With regard to the amplitude of the interannual variations, CRU is better than either of the reanalyses in representing the corresponding observations. The amplitude in NCEP-2 is stronger but that of ERA-40 is weaker than the observations in most study domains. NCEP-2 has a more obvious interannual variability than ERA-40 or CRU in most areas of East China. Through an Empirical orthogonal function (EOF) analysis, the main features of the rainfall belts produced by CRU aggree better with the observations than with those produced by the reanalyses in the Yangtze-Huaihe River valley. In East of China, particularly in the Yangtze-Huaihe River valley, CRU can reveal the quasi-biennial oscillation of summer precipitation represented by the observations, but the signal of ERA-40 is comparatively weak and not very obvious, whereas that of NCEP-2 is also weak before 1990 but very strong after 1990. The results also suggest that the magnitude of the precipitation difference between ERA-40 and the observations is smaller than that between NCEP-2 and the observations, but the variations represented by NCEP-2 are

  4. Assessing the performance of satellite-based precipitation products and its dependence on topography over Poyang Lake basin

    NASA Astrophysics Data System (ADS)

    Li, Xianghu; Zhang, Qi; Xu, Chong-Yu

    2014-02-01

    Satellite-based precipitation products (SPPs) have greatly improved their applicability and are expected to offer an alternative to ground-based precipitation estimates in the present and the foreseeable future. There is a strong need for a quantitative evaluation of the usefulness and limitations of SPPs in operational meteorology and hydrology. This study compared two widely used high-resolution SPPs, the Tropical Rainfall Measuring Mission (TRMM) and Precipitation Estimation from Remote Sensing Information using Artificial Neural Network (PERSIANN) in Poyang Lake basin which is located in the middle reach of the Yangtze River in China. The bias of rainfall amount and occurrence frequency under different rainfall intensities and the dependence of SPPs performance on elevation and slope were investigated using different statistical indices. The results revealed that (1) TRMM 3B42 usually underestimates the rainy days and overestimates the average rainfall as well as annual rainfall, while the PERSIANN data were markedly lower than rain gauge data; (2) the rainfall contribution rates were underestimated by TRMM 3B42 in the middle rainfall class but overestimated in the heavy rainfall class, while the opposite trend was observed for PERSIANN; (3) although the temporal distribution characteristics of monthly rainfall were correctly described by both SPPs, PERSIANN tended to suffer a systematic underestimation of rainfall in every month; and (4) the performances of both SPPs had clear dependence on elevation and slope, and their relationships can be fitted using quadratic equations.

  5. No-wash ethanol precipitation of dye-labeled reaction products improves DNA sequencing reads.

    PubMed

    Fujikura, Kohei

    2015-01-01

    The advent of DNA sequencing has significantly accelerated molecular biology and clinical genetic testing. Despite recent increases in next-generation sequencing throughput, the most popular platform for DNA sequencing is still the multi-capillary DNA sequencer, which is ideally suited for small-scale sequencing projects and is highly accurate. However, the methods remain time-consuming and laborious. Here, I describe a modified ethylenediaminetetraacetic acid (EDTA) method that skips the washing step in ethanol precipitation. My improvements to standard methods save labor, time, and cost per run and increase the sequence reads by 5 to 10%. This modified method will provide immediate benefits to many researchers. PMID:25256164

  6. Analysis of the Diurnal Cycle of Precipitation and its Relation to Cloud Radiative Forcing Using TRMM Products

    NASA Technical Reports Server (NTRS)

    Randall, David A.; Fowler, Laura D.; Lin, Xin

    1998-01-01

    In order to improve our understanding of the interactions between clouds, radiation, and the hydrological cycle simulated in the Colorado State University General Circulation Model (CSU GCM), we focused our research on the analysis of the diurnal cycle of precipitation, top-of-the-atmosphere and surface radiation budgets, and cloudiness using 10-year long Atmospheric Model Intercomparison Project (AMIP) simulations. Comparisons the simulated diurnal cycle were made against the diurnal cycle of Earth Radiation Budget Experiment (ERBE) radiation budget and International Satellite Cloud Climatology Project (ISCCP) cloud products. This report summarizes our major findings over the Amazon Basin.

  7. Validation of TRMM-3B42 precipitation product over the tropical Indian Ocean using rain gauge data from the RAMA buoy array

    NASA Astrophysics Data System (ADS)

    Prakash, Satya; Gairola, R. M.

    2014-02-01

    In the present study, an attempt has been made to validate the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA)-3B42 recently released version 7 product over the tropical Indian Ocean using surface rain gauges from the National Oceanic and Atmospheric Administration/Pacific Marine Environmental Laboratory Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction buoy array available since late 2004. The validation exercise is carried out at daily scale for an 8-year period of 2004-2011. Results show statistically significant linear correlation between these two precipitation estimates ranging from 0.40 to 0.89 and the root-mean-square error varies from about 1 to 22 mm day-1. Although systematic overestimation of precipitation by the TMPA product is evident over most of the buoy locations, the TMPA noticeably underestimates higher (more than 100 mm day-1) and light (less than 0.5 mm day-1) precipitation events. The highest correlation is observed during the southwest monsoon season (June-September) even though bias is the maximum possibly due to relatively lower fraction of stratiform precipitation during the monsoon season than other seasons. Furthermore, the TMPA estimates slightly underestimate or misses intermittent warm precipitation events as compared to the precipitation radar derived precipitation rates.

  8. Impact of parameter fluctuations on the performance of ethanol precipitation in production of Re Du Ning Injections, based on HPLC fingerprints and principal component analysis.

    PubMed

    Sun, Li-Qiong; Wang, Shu-Yao; Li, Yan-Jing; Wang, Yong-Xiang; Wang, Zhen-Zhong; Huang, Wen-Zhe; Wang, Yue-Sheng; Bi, Yu-An; Ding, Gang; Xiao, Wei

    2016-01-01

    The present study was designed to determine the relationships between the performance of ethanol precipitation and seven process parameters in the ethanol precipitation process of Re Du Ning Injections, including concentrate density, concentrate temperature, ethanol content, flow rate and stir rate in the addition of ethanol, precipitation time, and precipitation temperature. Under the experimental and simulated production conditions, a series of precipitated resultants were prepared by changing these variables one by one, and then examined by HPLC fingerprint analyses. Different from the traditional evaluation model based on single or a few constituents, the fingerprint data of every parameter fluctuation test was processed with Principal Component Analysis (PCA) to comprehensively assess the performance of ethanol precipitation. Our results showed that concentrate density, ethanol content, and precipitation time were the most important parameters that influence the recovery of active compounds in precipitation resultants. The present study would provide some reference for pharmaceutical scientists engaged in research on pharmaceutical process optimization and help pharmaceutical enterprises adapt a scientific and reasonable cost-effective approach to ensure the batch-to-batch quality consistency of the final products. PMID:26850350

  9. PRODUCTION OF PLUTONIUM FLUORIDE FROM BISMUTH PHOSPHATE PRECIPITATE CONTAINING PLUTONIUM VALUES

    DOEpatents

    Brown, H.S.; Bohlmann, E.G.

    1961-05-01

    A process is given for separating plutonium from fission products present on a bismuth phosphate carrier. The dried carrier is first treated with hydrogen fluoride at between 500 and 600 deg C whereby some fission product fluorides volatilize away from plutonium tetrafluoride, and nonvolatile fission product fluorides are formed then with anhydrous fluorine at between 400 and 500 deg C. Bismuth and plutonium distill in the form of volatile fluorides away from the nonvolatile fission product fluorides. The bismuth and plutonium fluorides are condensed at below 290 deg C.

  10. Updated Gridded Analysis Products provided by the Global Precipitation Climatology Centre (GPCC), its Quality Control, and Interpolation Schemes

    NASA Astrophysics Data System (ADS)

    Ziese, M.; Schneider, U.; Meyer-Christoffer, A.; Finger, P.; Lehner, K.; Rustemeier, E.; Becker, A.; Rudolf, B.

    2012-04-01

    Since its start in 1989 the Global Precipitation Climatology Centre (GPCC) performs global analyses of monthly precipitation for the earth's land-surface on the basis of in-situ measurements. Meanwhile, the data set has continuously grown both in temporal coverage (original start of the evaluation period was 1986), as well as extent and quality of the underlying data base. The high spatio-temporal variability of precipitation requires a high density of measurement data. Data collected from national meteorological and hydrological services are core of the GPCC data base, supported by global and regional data collections. Also the GPCC receives SYNOP and CLIMAT reports via WMO-GTS, which are mainly applied for near-real-time products. Any time new data sets are loaded to the data base the metadata in the input data set are compared to those already available and the data are checked against background statistics. Exceptional values are checked and either confirmed, corrected or excluded from the analyses. A high quality control effort is undertaken to remove miscoded and temporal or spatial dislocated data before interpolation. The product suite of the GPCC contains near-real-time as well as non-real-time products. Near-real-time products are the 'First Guess', which is available 3 - 5 days after the end of each month, based on SYNOP reports and an automatic quality control. The 'Monitoring Product' is available two months later and based on CLIMAT and SYNOP reports, which have passed a manual quality control. Non-real-time products are the 'Climatology' and 'Full Data Reanalysis', both based on stations with climatological normals and a further enhanced quality control. Core data are those from national meteorological and hydrological services and other collections, additionally supported by CLIMAT and SYNOP reports. 'VASClimO' is the currently homogenized product. In 2012 an analysis of daily precipitation is scheduled to start on basis of global SYNOP reports

  11. Design of a continuous process setup for precipitated calcium carbonate production from steel converter slag.

    PubMed

    Mattila, Hannu-Petteri; Zevenhoven, Ron

    2014-03-01

    A mineral carbonation process "slag2PCC" for carbon capture, utilization, and storage is discussed. Ca is extracted from steel slag by an ammonium salt solvent and carbonated with gaseous CO2 after the separation of the residual slag. The solvent is reused after regeneration. The effects of slag properties such as the content of free lime, fractions of Ca, Si, Fe, and V, particle size, and slag storage on the Ca extraction efficiency are studied. Small particles with a high free-lime content and minor fractions of Si and V are the most suitable. To limit the amount of impurities in the process, the slag-to-liquid ratio should remain below a certain value, which depends on the slag composition. Also, the design of a continuous test setup (total volume ∼75 L) is described, which enables quick process variations needed to adapt the system to the varying slag quality. Different precipitated calcium carbonate crystals (calcite and vaterite) are generated in different parts of the setup. PMID:24578147

  12. Detect signals of interdecadal climate variations from an enhanced suite of reconstructed precipitation products since 1850 using the historical station data from Global Historical Climatology Network and the dynamical patterns derived from Global Precipitation Climatology Project

    NASA Astrophysics Data System (ADS)

    Shen, S. S.

    2015-12-01

    This presentation describes the detection of interdecadal climate signals in a newly reconstructed precipitation data from 1850-present. Examples are on precipitation signatures of East Asian Monsoon (EAM), Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillations (AMO). The new reconstruction dataset is an enhanced edition of a suite of global precipitation products reconstructed by Spectral Optimal Gridding of Precipitation Version 1.0 (SOGP 1.0). The maximum temporal coverage is 1850-present and the spatial coverage is quasi-global (75S, 75N). This enhanced version has three different temporal resolutions (5-day, monthly, and annual) and two different spatial resolutions (2.5 deg and 5.0 deg). It also has a friendly Graphical User Interface (GUI). SOGP uses a multivariate regression method using an empirical orthogonal function (EOF) expansion. The Global Precipitation Climatology Project (GPCP) precipitation data from 1981-20010 are used to calculate the EOFs. The Global Historical Climatology Network (GHCN) gridded data are used to calculate the regression coefficients for reconstructions. The sampling errors of the reconstruction are analyzed according to the number of EOF modes used in the reconstruction. Our reconstructed 1900-2011 time series of the global average annual precipitation shows a 0.024 (mm/day)/100a trend, which is very close to the trend derived from the mean of 25 models of the CMIP5 (Coupled Model Intercomparison Project Phase 5). Our reconstruction has been validated by GPCP data after 1979. Our reconstruction successfully displays the 1877 El Nino (see the attached figure), which is considered a validation before 1900. Our precipitation products are publically available online, including digital data, precipitation animations, computer codes, readme files, and the user manual. This work is a joint effort of San Diego State University (Sam Shen, Gregori Clarke, Christian Junjinger, Nancy Tafolla, Barbara Sperberg, and

  13. Biomass and production of amphipods in low alkalinity lakes affected by acid precipitation.

    PubMed

    France, R L

    1996-01-01

    Population biomass and production of the amphipod Hyalella azteca (Saussure) were found to be related to alkalinity (ranging from 0.2 to 58.1 mg liter(-1)) in 10 Canadian Shield lakes in south-central Ontario. Biomass and production of amphipods in the two lakes characterized by spring depressions of pH below 5.0 were found to be lower than those for populations inhabiting lakes that did not experience such acid pulses. The proportional biomass of amphipods in relation to the total littoral zoobenthos community was lower in lakes of low alkalinity than in circumneutral or hardwater lakes. Because production in these amphipod populations is known to depend closely on population abundance, the labour-intensive derivation of production rates yields relatively little information for biomonitoring that cannot be obtained from abundance data alone. PMID:15093505

  14. Evaluation of feed COD/sulfate ratio as a control criterion for the biological hydrogen sulfide production and lead precipitation.

    PubMed

    Velasco, Antonio; Ramírez, Martha; Volke-Sepúlveda, Tania; González-Sánchez, Armando; Revah, Sergio

    2008-03-01

    The ability of sulfate-reducing bacteria to produce hydrogen sulfide and the high affinity of sulfide to react with divalent metallic cations represent an excellent option to remove heavy metals from wastewater. Different parameters have been proposed to control the hydrogen sulfide production by anaerobic bacteria, such as the organic and sulfate loading rates and the feed COD/SO4(2-) ratio. This work relates the feed COD/SO4(2-) ratio with the hydrogen sulfide production and dissolved lead precipitation, using ethanol as carbon and energy source in an up-flow anaerobic sludge blanket reactor. A maximum dissolved sulfide concentration of 470+/-7 mg S/L was obtained at a feed COD/SO4(2-) ratio of 2.5, with sulfate and ethanol conversions of approximately 94 and 87%, respectively. The lowest dissolved sulfide concentration (145+/-10 mg S/L) was observed with a feed COD/SO4(2-) ratio of 0.67. Substantial amounts of acetate (510-1730 mg/L) were produced and accumulated in the bioreactor from ethanol oxidation. Although only incomplete oxidation of ethanol to acetate was observed, the consortium was able to remove 99% of the dissolved lead (200 mg/L) with a feed COD/SO4(2-) ratio of 1.5. It was found that the feed COD/SO4(2-) ratio could be an adequate parameter to control the hydrogen sulfide production and the consequent precipitation of dissolved lead. PMID:17640800

  15. A hybrid Bayesian-SVD based method to detect false alarms in PERSIANN precipitation estimation product using related physical parameters

    NASA Astrophysics Data System (ADS)

    Ghajarnia, Navid; Arasteh, Peyman D.; Araghinejad, Shahab; Liaghat, Majid A.

    2016-07-01

    Incorrect estimation of rainfall occurrence, so called False Alarm (FA) is one of the major sources of bias error of satellite based precipitation estimation products and may even cause lots of problems during the bias reduction and calibration processes. In this paper, a hybrid statistical method is introduced to detect FA events of PERSIANN dataset over Urmia Lake basin in northwest of Iran. The main FA detection model is based on Bayesian theorem at which four predictor parameters including PERSIANN rainfall estimations, brightness temperature (Tb), precipitable water (PW) and near surface air temperature (Tair) is considered as its input dataset. In order to decrease the dimensions of input dataset by summarizing their most important modes of variability and correlations to the reference dataset, a technique named singular value decomposition (SVD) is used. The application of Bayesian-SVD method in FA detection of Urmia Lake basin resulted in a trade-off between FA detection and Hit events loss. The results show success of proposed method in detecting about 30% of FA events in return for loss of about 12% of Hit events while better capability of this method in cold seasons is observed.

  16. The impact of land-use change on the sensitivity of terrestrial productivity to precipitation variability: a modelling approach

    NASA Astrophysics Data System (ADS)

    Batlle-Bayer, L.; van den Hurk, B. J. J. M.; Müller, C.; van Minnen, J.

    2014-05-01

    Larger climate variability and more frequent extreme events (e.g. droughts) are expected to occur. Hence, assessing the sensitivity (response) of terrestrial net primary productivity (NPP) to climate variability is crucial for future estimations of terrestrial carbon sequestration. We hypothesize that land-use change (LUC) can modify this sensitivity, defined here as the anomaly correlation between annual NPP and precipitation in the growing season. To assess this changing sensitivity, we use the LPJmL model driven by observed climate variability and two different land-use sets. We find that the effect of LUC is mostly extended in semi-arid grasslands: sensitivity increases with conversion into rainfed crops, but it does not change for managed pasture expansion. Reforestation in temperate regions generally decreases sensitivity: trees are able to respond later to water deficit due to their deep root system. The expansion of irrigation in northern India reduces sensitivity since water availability is not a limiting factor for crop growth. Although we are able to identify spatial patterns of changes in NPP-precipitation sensitivity, the significance of our results focusing at isolation of the land-use effect is limited.

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

    NASA Technical Reports Server (NTRS)

    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.

  18. Global Net Primary Production Predicted from Vegetation Class, Precipitation, and Temperature.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Net Primary Production (NPP), the difference between CO2 fixed by photosynthesis and CO2 lost to autotrophic respiration, is one of the most important components of the carbon cycle. Our goal was to develop a simple regression model to estimate global NPP using climate and land cover data. Approxima...

  19. Accuracy and application of quantitative X-ray diffraction on the precipitation of struvite product.

    PubMed

    Lu, Xingwen; Shih, Kaimin; Li, Xiao-Yan; Liu, Guoqiang; Zeng, Eddy Y; Wang, Fei

    2016-03-01

    Struvite (MgNH4PO4·6H2O) crystallization from wastewater can gain a great advantage for phosphorus recovery and recycling. Although the recovery process and reaction modeling have been investigated, few studies have been conducted to quantify the different phases in recovered phosphorus products. The quantitative X-ray diffraction (QXRD) technique was employed in the present study to quantitatively determine the crystal phases and amorphous content of recovered struvite-containing products. Substantial mixed phase samples (i.e. struvite, newberyite and amorphous phase) were prepared to perform quantitative analysis to calibrate against known phase composition information by Rietveld refinement on powder X-ray diffraction data. The results showed a high level of accuracy (mean error = ∼3%) in our quantification model and validated the use of the Rietveld method to quantify the amorphous and crystal phases in the struvite-containing products. In addition, the influence of N:P molar ratio on struvite crystallization suggested that the weight percentage of struvite increased from 52% to 93%, when the N:P molar ratio was elevated from 0.2:1 to 1.2:1. This finding suggested the effectiveness of QXRD in facilitating the recovery of quality struvite products from waste streams. PMID:26724434

  20. Extracellular matrix production and calcium carbonate precipitation by coral cells in vitro.

    PubMed

    Helman, Yael; Natale, Frank; Sherrell, Robert M; Lavigne, Michèle; Starovoytov, Valentin; Gorbunov, Maxim Y; Falkowski, Paul G

    2008-01-01

    The evolution of multicellularity in animals required the production of extracellular matrices that serve to spatially organize cells according to function. In corals, three matrices are involved in spatial organization: (i) an organic ECM, which facilitates cell-cell and cell-substrate adhesion; (ii) a skeletal organic matrix (SOM), which facilitates controlled deposition of a calcium carbonate skeleton; and (iii) the calcium carbonate skeleton itself, which provides the structural support for the 3D organization of coral colonies. In this report, we examine the production of these three matrices by using an in vitro culturing system for coral cells. In this system, which significantly facilitates studies of coral cell physiology, we demonstrate in vitro excretion of ECM by primary (nondividing) tissue cultures of both soft (Xenia elongata) and hard (Montipora digitata) corals. There are structural differences between the ECM produced by X. elongata cell cultures and that of M. digitata, and ascorbic acid, a critical cofactor for proline hydroxylation, significantly increased the production of collagen in the ECM of the latter species. We further demonstrate in vitro production of SOM and extracellular mineralized particles in cell cultures of M. digitata. Inductively coupled plasma mass spectrometry analysis of Sr/Ca ratios revealed the particles to be aragonite. De novo calcification was confirmed by following the incorporation of (45)Ca into acid labile macromolecules. Our results demonstrate the ability of isolated, differentiated coral cells to undergo fundamental processes required for multicellular organization. PMID:18162537

  1. Global Potential Net Prmary Production Predicted from Vegetation Class, Precipitation, and Temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Net Primary Production (NPP), the difference between CO2 fixed by photosynthesis and CO2 lost to autotrophic respiration, is one of the most important components of the carbon cycle. Our goal was to develop a simple regression model to estimate global NPP using climate and land cover data. Approxima...

  2. How the Structure of Mesoscale Precipitation Systems Affects their Production of Transient Luminous Events

    NASA Astrophysics Data System (ADS)

    Lang, T. J.; Lyons, W.; Rutledge, S. A.; Cummer, S. A.; MacGorman, D. R.

    2011-12-01

    Recently, Lang et al. (2010) analyzed the parent lightning of transient luminous events (TLEs) in the context of the structure and evolution of two mesoscale convective systems (MCSs). These two MCSs were very different - one a giant symmetric leading-line/trailing stratiform storm, and one a small asymmetric MCS that contained a mesoscale convective vortex. These structural differences were associated with substantially different TLE-parent lightning structure as well as TLE production. The results suggested that TLE (especially sprite) production, and TLE-parent positive charge altitude, depend on MCS morphology. Current work is focused on analyzing the structure, evolution, lightning behavior, and TLE production of additional MCSs over various regions of the United States. Several additional TLE-producing MCS cases already have been identified for the years 2008-2010, featuring a variety of organizational modes (symmetric, asymmetric, and other more exotic varieties) in different meteorological regimes (including some cold-season cases). More cases will be incorporated as they occur and are observed. Data sources include geostationary satellite imagery, Doppler radar, three-dimensional lightning mapping networks, ground-strike detection networks, charge moment change measurements, and low-light video observations. The ultimate goal is to further test the hypothesis that MCS structure affects TLE production, and if so to quantify its impact. Research on two Oklahoma case studies, a multicellular system that occurred on 24 March 2009 and a classic bow-echo MCS that occurred on 19 August 2009, is ongoing. Over a 2.5-h period, the March case produced 23 observed TLEs (all sprites) whose parent flashes occurred within 175 km of the Oklahoma Lightning Mapping Array (OKLMA). The median altitude of LMA sources during the TLEs was 5.9 km above Mean Sea Level (MSL), or -19.2 °C. The August storm produced, in 2.5 hours, 34 TLEs (all sprites) with 32 of those having parent

  3. The utility of satellite precipitation products for hydrologic prediction in topographically complex regions: The Chehalis River Basin, WA as a case study

    NASA Astrophysics Data System (ADS)

    Cao, Q.; Mehran, A.; Lettenmaier, D. P.; Mass, C.; Johnson, N.

    2015-12-01

    Accurate measurements of precipitation are of great importance in hydrologic predictions especially for floods, which are a pervasive natural hazard. One of the primary objectives of Global Precipitation Measurement (GPM) mission is to provide a basis for hydrologic predictions using satellite sensors. A major advance in GPM relative to the Tropical Rainfall Measuring Mission (TRMM) is that it observes atmospheric river (AR) events, most of which have landfall too far north to be tracked by TRMM. These events are responsible for most major floods along the U.S. West Coast. We address the question of whether, for hydrologic modeling purposes, it is better to use precipitation products derived directly from GPM and/or other precipitation fields from weather models that have assimilated satellite data. Our overall strategy is to compare different methods for prediction of flood and/or high flow events by different forcings on the hydrologic model. We examine four different configurations of the Distroibute Hydrology Soil Vegetation Model (DHSVM) over the Chehalis River Basin that use a) precipitation forcings based on gridded station data; b) precipitation forcings based on NWS WSR-88D data, c) forcings based from short-term precipitation forecasts using the Weather Research and Forecasting (WRF) mesoscale atmospheric model, and d) satellite-based precipitation estimates (TMPA and IMERG). We find that in general, biases in the radar and satellite products result in much larger errors than with either gridded station data or WRF forcings, but if these biases are removed, comparable performance in flood predictions can be achieved by Satellite-based precipitation estimates (TMPA and IMERG).

  4. Characterization of condensed tannins purified from legume forages: chromophore production, protein precipitation, and inhibitory effects on cellulose digestion.

    PubMed

    McAllister, Tim A; Martinez, Tomas; Bae, Hee Dong; Muir, Alister D; Yanke, L Jay; Jones, Graham A

    2005-09-01

    To identify simple screening tools for selecting condensed tannin (CT)-containing forages as candidate sources for further study, CT were isolated from nine legumes, and their molecular weights (MW), chromophore production, capacity to precipitate bovine serum albumin (BSA) and Fraction 1 protein (Rubisco) isolated from alfalfa, and inhibition of filter paper digestion were compared. Sources were as follows: leaves of sericea lespedeza (Lespedeza cuneata Dum.-Cours.), crown vetch (Coronilla varia L.), and sainfoin (Onobrychis viciifolia Scop.); stems of hedysarum (Hedysarum alpinum L.); seeds of alfalfa (Medicago sativa L.); and whole plants of birdsfoot trefoil (Lotus corniculatus var. corniculatus L.) and three varieties of big trefoil (Lotus pedunculatus Cav.), viz., Lotus uliginosus Schkuhr, L. uliginosus var. glabriusculus, and L. uliginosus var. villosus. Molecular weights and sizes (degrees of polymerization) of the CT varied considerably within and among plant species. Average MW ranged from 3036 Da (crown vetch) to 7143 Da (lespedeza). All CT exhibited greater capacity (w/w basis) to bind alfalfa Rubisco than BSA. Relative astringencies (microg CT required to precipitate 1 mg protein) against BSA ranged from 262.5 for CT from lespedeza to 435.5 for CT from L. corniculatus, and against Rubisco, from 49.6 (sainfoin) to 108.2 (alfalfa seed). Including CT at 300 microg/ml in cultures of Fibrobacter succinogenes reduced digestion of cellulose filter paper by 19.8% (sainfoin) to 92.4% (crown vetch) and increased the specific activity of cell-associated endoglucanase. There were no correlations between inhibitory effects of CT on filter paper digestion and (1) chromophore formation during CT assay by butanol-HCl, vanillin-HCl, or H2SO4; (2) precipitation of BSA or alfalfa Rubisco; and (3) MW of CT. The most inhibitory CT for cellulose digestion included those with broad and with narrow MW distributions. Sainfoin was the most desirable source of CT, as it had the

  5. An assessment of the precipitation product of the EC-Earth dataset in the period 1981-2000

    NASA Astrophysics Data System (ADS)

    Campo, Lorenzo; Silvestro, Francesco; Rudari, Roberto

    2014-05-01

    The increasing availability of Global Circulation Model (GCM) simulations that span historical periods (part or the whole 20th century) created a number of large meteorological variables datasets, with particular reference to the precipitation. Given the complexity of such models and the incertitude about the forcing or the configuration, with reference, for instance, to the astronomical solar radiation time series, or the presence of data assimilation from different sources or, again, the possible coupling with oceanic dynamics, a validation of such datasets becomes fundamental for assessing either the accuracy of the simulation, the meteorological features that the model can reproduce and the differences between different models/simulations. In this work the rainfall product of the EC-Earth model simulation, based on the ECMWF Seasonal Forecasting System, was compared with a global dataset of observed precipitation, CHIRPS. The simulation taken into consideration in this study was open-loop (without assimilation), the simulated period ranging from 1960 to 2012. For this reason only statistical characteristics of the simulated rainfall were considered in the comparison. The CHIRPS dataset is constituted by a merging of satellite-measured rainfall and ground rain gauges network, it covers the period 1981-2012 and it is spatially limited to the band of the land between 50 degrees South Latitude and 50 degrees of North Latitude. The comparison with the EC-Earth rainfall dataset was then limited to this spatial extent and to the period 1981-2000. The analysis was performed both in terms of spatial patterns and differences in the characteristics of the time series on a pixel-per-pixel basis.

  6. A Validation Study of the NWS/MPE Precipitation Products Using a Dense Rain Gauge Network in South Louisiana

    NASA Astrophysics Data System (ADS)

    Larson, B. F.; Habib, E.; Graschel, J.; Nelson, B. R.

    2007-12-01

    This study focuses on validation of the multi-sensor precipitation products developed by the operational multi- sensor precipitation estimation (MPE) algorithm of the National Weather Service (NWS) River Forecast Centers (RFC). MPE data are acquired through the Stage IV archives at the National Center for Environmental Prediction (NCEP). MPE data, which is based upon the merging of data from WSR-88D radar, surface rain gauge, and occasionally geo-stationary satellite data, is provided at hourly temporal resolution and over a national Hydrologic Rainfall Analysis Project (HRAP) grid which has a nominal size of 4 square kilometers. Operational hydrologic forecasting applications now require higher spatial and temporal resolution which is provided by radar data. To help determine the validity of radar data in south Louisiana, a study was performed on MPE data for a three-year period (2004-2006) using 13 independently operated rain gauges located within an area of ~30 km2. The close proximity of gauge sites to each other allows for multiple gauges to be located within the same HRAP pixel. As a result, two pixels contained four gauges each, and one pixel contained two gauges. This co-location of multiple gauges within an HRAP pixel allows for a reasonably accurate estimation of the MPE errors over different scales such as hourly, daily, and monthly temporal resolution. In this context, the errors are defined as the deviation of MPE estimates from the corresponding average of gauge measurements in each pixel. The self dependence of these errors is assessed by analyzing their temporal and spatial auto-correlations. The MPE products are mainly intended for operational hydrologic forecasting. Therefore, the study will examine the impact of MPE uncertainties on runoff simulations in a mid-size experimental watershed in south Louisiana. The physically- based hydrologic model (Gridded Surface Subsurface Hydrologic Analysis, GSSHA) is driven by two sets of rainfall forcing: MPE

  7. Detection of chlorodifluoroacetic acid in precipitation: A possible product of fluorocarbon degradation

    SciTech Connect

    Martin, J.W.; Franklin, J.; Hanson, M.L.; Solomon, K.R.; Mabury, S.A.; Ellis, D.A.; Scott, B.F.; Muri, D.C.G.

    2000-01-15

    Chlorodiffluoroacetic acid (CDFA) was detected in rain and snow samples from various regions of Canada. Routine quantitative analysis was performed using an in-situ derivatization technique that allowed for the determination of CDFA by GC-MS of the anilide derivative. Validation of environmental CDFA was provided by strong anionic exchange chromatography and detection by {sup 19}F NMR. CDFA concentrations ranges from <7.1 to 170 ng L{sup {minus}1} among all samples analyzed. Monthly volume-weighted CDFA concentrations ranged from <7.1 to 170 ng L{sup {minus}1} among all samples analyzed. Monthly volume-weighted CDFA concentrations in rain event samples showed a seasonal trend between June and November 1998, peaking in late summer and decreasing in the fall for Guelph and Toronto sites. Preliminary toxicity tests with the aquatic macrophytes Myriophyllum sibiricum and Myriophyllum spicatum suggest that CDFA does not represent a risk of acute toxicity to these aquatic macrophytes at current environmental concentrations. A degradation study suggests that CDFA is recalcitrant to biotic and abiotic degradation relative to dichloroacetic acid (DCA) and may accumulate in the aquatic environment. On the basis of existing experimental data, the authors postulate that CDFA is a degradation product of CFC-113 and, to a lesser extent, HCFC-142b. If CFC-113 is a source, its ozone depletion potential may be lower than previously assumed. Further work is required to identify alternative atmospheric and terrestrial sources of CDFA.

  8. Evaluation of the TMPA-3B42 precipitation product using a high-density rain gauge network over complex terrain in northeastern Iberia

    NASA Astrophysics Data System (ADS)

    El Kenawy, Ahmed M.; Lopez-Moreno, Juan I.; McCabe, Matthew F.; Vicente-Serrano, Sergio M.

    2015-10-01

    The performance of the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA)-3B42 version 7 product is assessed over north-eastern Iberia, a region with considerable topographical gradients and complexity. Precipitation characteristics from a dense network of 656 rain gauges, spanning the period from 1998 to 2009, are used to evaluate TMPA-3B42 estimates on a daily scale. A set of accuracy estimators, including the relative bias, mean absolute error (MAE), root mean square error (RMSE) and Spearman coefficient was used to evaluate the results. The assessment indicates that TMPA-3B42 product is capable of describing the seasonal characteristics of the observed precipitation over most of the study domain. In particular, TMPA-3B42 precipitation agrees well with in situ measurements, with MAE less than 2.5 mm.day- 1, RMSE of 6.4 mm.day- 1 and Spearman correlation coefficients generally above 0.6. TMPA-3B42 provides improved accuracies in winter and summer, whereas it performs much worse in spring and autumn. Spatially, the retrieval errors show a consistent trend, with a general overestimation in regions of low altitude and underestimation in regions of heterogeneous terrain. TMPA-3B42 generally performs well over inland areas, while showing less skill in the coastal regions. A set of skill metrics, including a false alarm ratio [FAR], frequency bias index [FBI], the probability of detection [POD] and threat score [TS], is also used to evaluate TMPA performance under different precipitation thresholds (1, 5, 10, 25 and 50 mm.day- 1). The results suggest that TMPA-3B42 retrievals perform well in specifying moderate rain events (5-25 mm.day- 1), but show noticeably less skill in producing both light (< 1 mm.day- 1) and heavy rainfall thresholds (more than 50 mm.day- 1). Given the complexity of the terrain and the associated high spatial variability of precipitation in north-eastern Iberia, the results reveal that TMPA-3B42 data provide

  9. Hydrological Evaluation of Satellite-Based Precipitation Products over the Volta and Baro-Akobo Basin

    NASA Astrophysics Data System (ADS)

    Thiemig, Vera; Zambrano, Mauricio; Rojas, Rodrigo; De Roo, Ad

    2013-04-01

    How useful are satellite-based rainfall estimates (SRFE) as forcing data for hydrological applications? Which SRFE should be favoured for hydrological modelling? What could researchers do to increase the performance of SRFE-driven hydrological simulations? To address these three research questions, four SRFE (CMORPH, RFE 2.0, TRMM-3B42 and PERSIANN) and one reanalysis product (ERA-Interim) are evaluated within a hydrological application for the time period 2003-2008, over two river basins (Volta and Baro-Akobo) which hold distinct physiographic, climatologic and hydrologic conditions. The focus was on the assessment of: a) the individual and combined effect of SRFE-specific calibration and bias-correction on the hydrological performance, b) the level of complexity required regarding bias-correction and interpolation to achieve a good hydrological performance, and c) the hydrological performance of SRFE during high- and low-flow conditions. Results show that 1) the hydrological performance is always higher if the model is calibrated to the respective SRFE rather than to interpolated ground observations; 2) for SRFE that are afflicted with bias, a bias-correction step prior to SRFE-specific calibration is essential, while for SRFE with good intrinsic data quality applying a SRFE-specific model calibration is sufficient; 3) the more sophisticated bias-correction method used in this work (histogram equalization) results generally in a superior hydrological performance, while a more sophisticated interpolation method (Kriging with External Drift) seems to be of added value only over mountainous regions; 4) the bias-correction is not over-proportionally important over mountainous catchments, as it solely depends on where the SRFE show high biases (e.g. for PERSIANN and CMORPH over lowland areas); and 5) the hydrological performance during high-flow conditions is superior thus promoting the use of SRFE for applications focusing on the high-end flow spectrum. These results

  10. Evaluation of TRMM-based Precipitation Products in the Southeast U. S. and Their Impact on Hydrological Modeling

    NASA Astrophysics Data System (ADS)

    Tian, Y.; Peters-Lidard, C. D.; Garcia, M.; Kumar, S. V.

    2006-05-01

    We have evaluated three TRMM-based precipitation datasets against the ground-based Higgins gage dataset (Higgins, et al., 2000) in Southeast US. The three TRMM-based datasets include 3B42RT, 3B42V6 (Huffman et al., 1995, 1997; Huffman, 1997), and CMORPH (Joyce, et al., 2004). We have performed temporal and spatial analysis on these products over the period from winter, 2002 to summer, 2005. Our timescale of analysis spans from seasonal to daily, and includes a case study of hurricane Jeanne, a 5-day event. In addition, we have investigated the impact of these products on land surface modeling, with the Goddard Land Information System (LIS; http://lis.gsfc.nasa.gov; Kumar et al., 2006). Our analysis has revealed that on monthly to seasonal timescales, 3B42V6 has the smallest errors and the best spatial patterns relative to the Higgins data. Both 3B42RT and CMORPH data have much larger errors on these timescales. In particular, they suffered large over-estimation for the 2003 and 2004 summers, mostly in the Florida panhandle and other coastal areas. For shorter timescales (1 to 10 days), 3B42RT and CMORPH also have overall larger errors, and these errors propagated to the longer timescales. For the individual hurricane Jeanne event, however, none of the three datasets reproduced faithfully the rainfall patterns. With LIS, we have demonstrated that the spatial and temporal patterns of the rainfall estimation greatly impacted surface runoff and thus the accuracy of flood prediction. In particular, during hurricane Jeanne's landfall, 3B42RT generated 31% more surface runoff than 3B42V6, and 35% more than CMORPH, with 12% and 8% less rainfall than the latter two products, respectively. The resulting errors in surface runoff had a very short timescale, while the errors in soil moisture had a much longer timescale of 1 to 2 months.

  11. Improving Quantitative Precipitation Estimation via Data Fusion of High-Resolution Ground-based Radar Network and CMORPH Satellite-based Product

    NASA Astrophysics Data System (ADS)

    Cifelli, R.; Chen, H.; Chandrasekar, V.; Xie, P.

    2015-12-01

    A large number of precipitation products at multi-scales have been developed based upon satellite, radar, and/or rain gauge observations. However, how to produce optimal rainfall estimation for a given region is still challenging due to the spatial and temporal sampling difference of different sensors. In this study, we develop a data fusion mechanism to improve regional quantitative precipitation estimation (QPE) by utilizing satellite-based CMORPH product, ground radar measurements, as well as numerical model simulations. The CMORPH global precipitation product is essentially derived based on retrievals from passive microwave measurements and infrared observations onboard satellites (Joyce et al. 2004). The fine spatial-temporal resolution of 0.05o Lat/Lon and 30-min is appropriate for regional hydrologic and climate studies. However, it is inadequate for localized hydrometeorological applications such as urban flash flood forecasting. Via fusion of the Regional CMORPH product and local precipitation sensors, the high-resolution QPE performance can be improved. The area of interest is the Dallas-Fort Worth (DFW) Metroplex, which is the largest land-locked metropolitan area in the U.S. In addition to an NWS dual-polarization S-band WSR-88DP radar (i.e., KFWS radar), DFW hosts the high-resolution dual-polarization X-band radar network developed by the center for Collaborative Adaptive Sensing of the Atmosphere (CASA). This talk will present a general framework of precipitation data fusion based on satellite and ground observations. The detailed prototype architecture of using regional rainfall instruments to improve regional CMORPH precipitation product via multi-scale fusion techniques will also be discussed. Particularly, the temporal and spatial fusion algorithms developed for the DFW Metroplex will be described, which utilizes CMORPH product, S-band WSR-88DP, and X-band CASA radar measurements. In order to investigate the uncertainties associated with each

  12. Calcium carbonate precipitation by heterotrophic bacteria isolated from biofilms formed on deteriorated ignimbrite stones: influence of calcium on EPS production and biofilm formation by these isolates.

    PubMed

    López-Moreno, Angélica; Sepúlveda-Sánchez, José David; Mercedes Alonso Guzmán, Elia Mercedes; Le Borgne, Sylvie

    2014-01-01

    Heterotrophic CaCO3-precipitating bacteria were isolated from biofilms on deteriorated ignimbrites, siliceous acidic rocks, from Morelia Cathedral (Mexico) and identified as Enterobacter cancerogenus (22e), Bacillus sp. (32a) and Bacillus subtilis (52g). In solid medium, 22e and 32a precipitated calcite and vaterite while 52g produced calcite. Urease activity was detected in these isolates and CaCO3 precipitation increased in the presence of urea in the liquid medium. In the presence of calcium, EPS production decreased in 22e and 32a and increased in 52g. Under laboratory conditions, ignimbrite colonization by these isolates only occurred in the presence of calcium and no CaCO3 was precipitated. Calcium may therefore be important for biofilm formation on stones. The importance of the type of stone, here a siliceous stone, on biological colonization is emphasized. This calcium effect has not been reported on calcareous materials. The importance of the effect of calcium on EPS production and biofilm formation is discussed in relation to other applications of CaCO3 precipitation by bacteria. PMID:24689777

  13. Effects of interannual precipitation variability on ecosystem water balance and its consequences for aboveground net primary production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate change will result in an increase in the variability of precipitation within and among years as a result of different atmospheric phenomena. For many locations, there will be larger precipitation events interspersed with longer periods of droughts within a year, and more sequences of extreme...

  14. Sources and fluxes of organic nitrogen in precipitation over the southern East/Japan Sea: potential impacts on marine productivity

    NASA Astrophysics Data System (ADS)

    Yan, G.; Kim, G.

    2014-12-01

    We measured total dissolved reactive nitrogen in precipitation samples collected at Uljin, a Korean coastal site upwind of the southern East/Japan Sea (EJS), selected as a representative study site of atmospheric deposition over the northwestern Pacific margin. NO3- was found to be the most abundant nitrogen species, followed by NH4+ and dissolved organic nitrogen (DON). Air mass back trajectory analysis revealed that a significant fraction of the inorganic nitrogen (NO3- and NH4+) originated from mainland Asia, whereas the DON was primarily derived from Korea. Using varimax-rotated factor analysis in combination with major ions as tracers, agricultural activities in Korea were identified as the primary sources of DON in these samples. In addition, a positive correlation was found at Uljin between the size of organic fraction in total reactive nitrogen and nitrogen to carbon atomic ratio in organic matter. This correlation has also been observed at other locations worldwide, implying the utilization potential of atmospheric organic nitrogen might increase with its proportion in total nitrogen. Combining wet deposition measurements in this study with literature values for dry deposition observed at a remote island in the EJS, the total atmospheric depositional flux of reactive nitrogen was estimated to be 115 mmol N m-2 yr-1 over the southern EJS. Our study sheds new light on the potentially significant contribution to primary productivity of the northwestern Pacific Ocean by atmospheric deposition of nitrogen, especially the organic fraction.

  15. Influence of nonnative and native ungulate biomass and seasonal precipitation on vegetation production in a Great Basin ecosystem

    USGS Publications Warehouse

    Zeigenfuss, Linda C.; Schoenecker, Kathryn A.; Ransom, Jason I.; Ignizio, Drew A.; Mask, Tracy

    2014-01-01

    The negative effects of equid grazers in semiarid ecosystems of the American West have been considered disproportionate to the influence of native ungulates in these systems because of equids' large body size, hoof shape, and short history on the landscape relative to native ungulates. Tools that can analyze the degree of influence of various ungulate herbivores in an ecosystem and separate effects of ungulates from effects of other variables (climate, anthropomorphic disturbances) can be useful to managers in determining the location of nonnative herbivore impacts and assessing the effect of management actions targeted at different ungulate populations. We used remotely sensed data to determine the influence of native and nonnative ungulates and climate on vegetation productivity at wildlife refuges in Oregon and Nevada. Our findings indicate that ungulate biomass density, particularly equid biomass density, and precipitation in winter and spring had the greatest influence on normalized difference vegetation index (NDVI) values. Our results concur with those of other researchers, who found that drought exacerbated the impacts of ungulate herbivores in arid systems.

  16. Production of sulfate aerosols in the plume of a coal-fired power plant under normal and reduced precipitator operation

    SciTech Connect

    Meagher, J.F.; Bailey, E.M.; Stockburger, L. III

    1981-12-01

    A series of field experiments were conducted at TVA's Cumberland Steam Plant to examine the effect of primary aerosol on sulfate aerosol production. Plume measurements were made using an instrumented helicopter and flue gas analyses were performed on each of the two stacks. The plume particle loading was increased during four of the experiments through a reduction in the electrostatic precipitator (ESP) capacity. The average rate of oxidation of SO/sub 2/ to SO/sub 4//sup 2 -/ in the plume was found to be 0.014 +- 0.015 h/sup -1/. The average rate measured for daytime and normal ESP operation was 0.019 +- 0.015 h/sup -1/. The average nighttime rate was also 0.019 +- 0.021 h/sup -1/. The average rate measured during periods of reduced ESP operation was 0.007 +- 0.01 h/sup -1/. The relatively high night-time rates were measured just after sunset and may result from delayed reactions of free radical precursors which were produced during the day-light hours. The difference between extrapolated intercepts from aircraft measurements and flue gas sampling indicates that a region of rapid SO/sub 2/ oxidation must exist for the first few minutes after the flue gas is emitted from the stacks.

  17. Comparison of versions 6 and 7 3-hourly TRMM multi-satellite precipitation analysis (TMPA) research products

    NASA Astrophysics Data System (ADS)

    Liu, Zhong

    2015-09-01

    This paper examines differences between Version 6 (V6) and Version 7 (V7) 3-hourly TRMM (Tropical Rainfall Measuring Mission) Multi-Satellite Precipitation Analysis (TMPA 3B42) research products in JJA (June, July and August) and DJF (December, January and February) over a 13-year period from 1998 to 2010 on a global scale. Different surface types and rain regimes are considered in the comparison. The study finds that more rain events are found in V7 than those in V6 in both JJA and DJF, especially over oceans. Overall, both versions show a good agreement in moderate and heavy rain regimes. High Pearson's correlation coefficients are found in tropical rain band regions. Histograms of both versions are very similar; however higher frequencies of rain events are found in V7 in light rain regime, especially over oceans, than those in V6. For light rain, rainfall estimates in V6 are less than those in V7 over land and oceans in both seasons. For moderate rain, rainfall estimates in V6 are larger than those in V7 over land in most years. Over oceans, it is a mixed situation in which V6 > V7 for some years and V6 < V7 for the other years. For heavy rain, rainfall estimates in V6 are larger than those in V7 throughout all JJA and DJF seasons for both land and oceans, which is also shown in a case study. Large variance in the individual differences is found in light rain and less in heavy rain. No apparent trends are observed. For light rain, all statistics support that there is an uncertainty issue in both versions.

  18. Comparing the skill of precipitation forecasts from high resolution simulations and statistically downscaled products in the Australian Snowy Mountains

    NASA Astrophysics Data System (ADS)

    Dai, J.; Chubb, T.; Manton, M.; Siems, S. T.

    2013-12-01

    Statistically significant improvements to a 'Poor Man's Ensemble' (PME) of coarse-resolution numeral precipitation forecast for the Australian Snowy Mountains can be achieved using a clustering algorithm. Daily upwind soundings are classified according to one of four clusters, which are employed to adjust the precipitation forecasts using a linear regression. This approach is a type of 'statistical downscaling', in that it relies on a historical relationship between observed and forecast precipitation amounts, and is a computationally cheap and fast way to improve forecast skill. For the 'wettest' class, the root-mean-square error for the one-day forecast was reduced from 26.98 to 17.08 mm, and for the second 'wet' class the improvement was from 8.43 to 5.57 mm. Regressions performed for the two 'dry' classes were not shown to significantly improve the forecast. Statistical measures of the probability of precipitation and the quantitative precipitation forecast were evaluated for the whole of the 2011 winter (May-September). With a 'hit rate' (fraction of correctly-forecast rain days) of 0.9, and a 'false alarm rate' (fraction of forecast rain days which did not occur) of 0.16 the PME forecast performs well in identifying rain days. The precipitation amount is, however systematically under-predicted, with a mean bias of -5.76 mm and RMSE of 12.86 mm for rain days during the 2011 winter. To compare the statistically downscaled results with the capabilities of a state of the art numerical prediction system, the WRF model was run at 4 km resolution over the Australian Alpine region for the same period, and precipitation forecasts analysed in a similar manner. It had a hit rate of 0.955 and RMSE of 5.16 mm for rain days. The main reason for the improved performance relative to the PME is that the high resolution of the simulations better captures the orographic forcing due to the terrain, and consequently resolves the precipitation processes more realistically, but

  19. High precipitation rate in a Middle Triassic carbonate platform: Implications on the relationship between seawater saturation state and carbonate production

    NASA Astrophysics Data System (ADS)

    Franceschi, Marco; Preto, Nereo; Marangon, Alessandro; Gattolin, Giovanni; Meda, Marco

    2016-06-01

    Three-dimensional geological modeling of the Middle Triassic Latemar carbonate platform is coupled with facies modal analysis to estimate its carbonate precipitation rate (G). The 3D model, strongly constrained by field data, encompasses a specific stratigraphic interval of the platform, bounded by two isochronous surfaces. Modal analysis of thin sections allows estimating the proportion of syndepositional vs postdepositional carbonate in the facies associations of the platform. This, together with the 3D facies distribution in the model that takes into account lateral and vertical facies variability, permits to calculate the volumes of syndepositional carbonate preserved at Latemar between the two considered isochrones. Given the peculiar characteristics of the platform, that does not show evidences of strong dissolution processes or large carbonate mass loss through export in the nearby basins, results can be used to estimate the average precipitation rate of the platform in the considered time interval. This estimate allows discussion in relation to models of ocean water saturation state (Ω) with respect to carbonates in the geological past, and comparison to the calculated precipitation rates of modern tropical coral reef ecosystems at global and reef scale. A high G value is found at Latemar and represents the first empirical confirmation that, in the Triassic, extremes in Ω may have triggered high carbonate precipitation in shallow water settings; moreover, comparison to modern reefs points to a possible common relationship that may link seawater Ω and precipitation rate in carbonate platform ecosystems through geological time.

  20. Production of Chondroitin Sulphate from Head, Skeleton and Fins of Scyliorhinus canicula By-Products by Combination of Enzymatic, Chemical Precipitation and Ultrafiltration Methodologies.

    PubMed

    Blanco, María; Fraguas, Javier; Sotelo, Carmen G; Pérez-Martín, Ricardo I; Vázquez, José Antonio

    2015-06-01

    This study illustrates the optimisation of the experimental conditions of three sequential steps for chondroitin sulphate (CS) recovery from three cartilaginous materials of Scyliorhinus canicula by-products. Optimum conditions of temperature and pH were first obtained for alcalase proteolysis of head cartilage (58 °C/pH 8.5/0.1% (v/w)/10 h of hydrolysis). Then, similar optimal conditions were observed for skeletons and fin materials. Enzymatic hydrolysates were subsequently treated with a combination of alkaline hydroalcoholic saline solutions in order to improve the protein hydrolysis and the selective precipitation of CS. Ranges of 0.53-0.64 M (NaOH) and 1.14-1.20 volumes (EtOH) were the levels for optimal chemical treatment depending on the cartilage origin. Finally, selective purification and concentration of CS and protein elimination of samples obtained from chemical treatment, was assessed by a combination of ultrafiltration and diafiltration (UF-DF) techniques at 30 kDa. PMID:26023837

  1. Production of Chondroitin Sulphate from Head, Skeleton and Fins of Scyliorhinus canicula By-Products by Combination of Enzymatic, Chemical Precipitation and Ultrafiltration Methodologies

    PubMed Central

    Blanco, María; Fraguas, Javier; Sotelo, Carmen G.; Pérez-Martín, Ricardo I.; Vázquez, José Antonio

    2015-01-01

    This study illustrates the optimisation of the experimental conditions of three sequential steps for chondroitin sulphate (CS) recovery from three cartilaginous materials of Scyliorhinus canicula by-products. Optimum conditions of temperature and pH were first obtained for alcalase proteolysis of head cartilage (58 °C/pH 8.5/0.1% (v/w)/10 h of hydrolysis). Then, similar optimal conditions were observed for skeletons and fin materials. Enzymatic hydrolysates were subsequently treated with a combination of alkaline hydroalcoholic saline solutions in order to improve the protein hydrolysis and the selective precipitation of CS. Ranges of 0.53–0.64 M (NaOH) and 1.14–1.20 volumes (EtOH) were the levels for optimal chemical treatment depending on the cartilage origin. Finally, selective purification and concentration of CS and protein elimination of samples obtained from chemical treatment, was assessed by a combination of ultrafiltration and diafiltration (UF-DF) techniques at 30 kDa. PMID:26023837

  2. Cloud and Precipitation Radar

    NASA Astrophysics Data System (ADS)

    Hagen, Martin; Höller, Hartmut; Schmidt, Kersten

    Precipitation or weather radar is an essential tool for research, diagnosis, and nowcasting of precipitation events like fronts or thunderstorms. Only with weather radar is it possible to gain insights into the three-dimensional structure of thunderstorms and to investigate processes like hail formation or tornado genesis. A number of different radar products are available to analyze the structure, dynamics and microphysics of precipitation systems. Cloud radars use short wavelengths to enable detection of small ice particles or cloud droplets. Their applications differ from weather radar as they are mostly orientated vertically, where different retrieval techniques can be applied.

  3. Relationship between extreme Precipitation and Temperature over Japan: An analysis from Multi-GCMs and Multi-RCMs products

    NASA Astrophysics Data System (ADS)

    Nayak, S.; Dairaku, K.; Takayabu, I.

    2014-12-01

    According to the IPCC reports, the concentration of CO­2 has been increasing and projected to be increased significantly in future (IPCC, 2012). This can have significant impacts on climate. For instance, Dairaku and Emori (2006) examined over south Asia by doubling CO2 and documented an increase in precipitation intensities during Indian summer monsoon. This would increase natural disasters such as floods, landslide, coastal disaster, erosion etc. Recent studies investigated whether the rate of increase of extreme precipitation is related with the rate expected by Clausius-Clapeyron (CC) relationship (approximately 7% per degree temperature rise). In our study, we examine whether this rate can increase or decrease in the future regional climate scenarios over Japan. We have analysed the ensemble experiments by three RCMs(NHRCM, NRAMS, WRF) forced by JRA25 as well as three GCMs (CCSM4, MIROC5, MRI-GCM3) for the current climate (1981-2000) and future scenario (2081-2100, RCP4.5) over Japan. We have stratified the extreme (99th, 95th, 90th, 75th percentile) precipitation of daily sum and daily maximum of hourly precipitation intensities of wet events based on daily mean temperature in bins of 1°C width for annual as well as for each season (DJF, MAM, JJA, SON). The results indicate that precipitation intensity increases when temperature increases roughly up to 22 °C and further increase of temperature decreases the precipitation intensities. The obtained results are consistent and match with the observation (APHRODITE dataset) over Japan. The decrease of precipitation at higher temperature mainly can be found in JJA. It is also noticed that the rate of specific humidity is estimated higher during JJA than other seasons. The rate of increase of extreme precipitation is similar to the rate expected by CC relation except DJF (nearly twice of CC relation) in current climate. This rate becomes to be significantly larger in future scenario for higher temperatures than

  4. The use of high-resolution atmospheric simulations over mountainous terrain for deriving error correction functions of satellite precipitation products

    NASA Astrophysics Data System (ADS)

    Bartsotas, Nikolaos S.; Nikolopoulos, Efthymios I.; Anagnostou, Emmanouil N.; Kallos, George

    2015-04-01

    Mountainous regions account for a significant part of the Earth's surface. Such areas are persistently affected by heavy precipitation episodes, which induce flash floods and landslides. The limitation of inadequate in-situ observations has put remote sensing rainfall estimates on a pedestal concerning the analyses of these events, as in many mountainous regions worldwide they serve as the only available data source. However, well-known issues of remote sensing techniques over mountainous areas, such as the strong underestimation of precipitation associated with low-level orographic enhancement, limit the way these estimates can accommodate operational needs. Even locations that fall within the range of weather radars suffer from strong biases in precipitation estimates due to terrain blockage and vertical rainfall profile issues. A novel approach towards the reduction of error in quantitative precipitation estimates lies upon the utilization of high-resolution numerical simulations in order to derive error correction functions for corresponding satellite precipitation data. The correction functions examined consist of 1) mean field bias adjustment and 2) pdf matching, two procedures that are simple and have been widely used in gauge-based adjustment techniques. For the needs of this study, more than 15 selected storms over the mountainous Upper Adige region of Northern Italy were simulated at 1-km resolution from a state-of-the-art atmospheric model (RAMS/ICLAMS), benefiting from the explicit cloud microphysical scheme, prognostic treatment of natural pollutants such as dust and sea-salt and the detailed SRTM90 topography that are implemented in the model. The proposed error correction approach is applied on three quasi-global and widely used satellite precipitation datasets (CMORPH, TRMM 3B42 V7 and PERSIANN) and the evaluation of the error model is based on independent in situ precipitation measurements from a dense rain gauge network (1 gauge / 70 km2

  5. Quality control, data base and gridded analysis products provided by the Global Precipitation Climatology Centre (GPCC) to serve the hydro-climatology community

    NASA Astrophysics Data System (ADS)

    Ziese, M.; Becker, A.; Schneider, U.; Meyer-Christoffer, A.; Finger, P.; Rudolf, B.

    2011-12-01

    Since its start in 1989 the Global Precipitation Climatology Centre (GPCC) performs global analyses of monthly precipitation for the earth's land-surface on the basis of in-situ measurements. Meanwhile, the data set has continuously grown both in temporal coverage (original start of the evaluation period was 1986), as well as extent and quality of the underlying data base. The high spatio-temporal variability of precipitation requires a high density of measurement data. The GPCC receives the SYNOP and CLIMAT messages in near real-time via the WMO GTS. Core data source of the GPCC analyses are the data from station networks operated by the National Meteorological/Hydrological Services worldwide; data deliveries have been received from ca. 190 countries. The GPCC integrates also other global precipitation data collections (i.e. FAO, CRU and GHCN), as well as regional data sets and has recently started collection and analysis of daily data while keeping its other activities upright. As a result of these efforts the GPCC holds the worldwide largest and most comprehensive collection of precipitation data, which is continuously updated and extended. The acquired data sets are pre-checked and imported into a relational data base, thus allowing a cross-comparison of data from the different sources. Any time new data sets are imported to the data base the metadata in the input data set are compared to those already available. Since the beginning of 2009 the precipitation data to be imported is compared against a background statistic. Exceptional values are checked and either confirmed, corrected or excluded from the analyses. Near-real-time products are the 'First Guess Product' (created for early detection, e.g., drought monitoring) and 'Monitoring Product' (created on WCRP request and for merging to satellite data), both with a spatial resolution of 1°x1°. Only an automatic quality control runs during the generation of the 'First Guess Product', whereas the data base is

  6. SPECIAL SESSION: (H21) on Global Precipitation Mission for Hydrology and Hydrometeorology. Sampling-Error Considerations for GPM-Era Rainfall Products

    NASA Technical Reports Server (NTRS)

    Bell, Thomas L.; Lau, William K. M. (Technical Monitor)

    2002-01-01

    The proposed Global Precipitation Mission (GPM) builds on the success of the Tropical Rainfall Measuring Mission (TRMM), offering a constellation of microwave-sensor-equipped smaller satellites in addition to a larger, multiply-instrumented "mother" satellite that will include an improved precipitation radar system to which the precipitation estimates of the smaller satellites can be tuned. Coverage by the satellites will be nearly global rather than being confined as TRMM was to lower latitudes. It is hoped that the satellite constellation can provide observations at most places on the earth at least once every three hours, though practical considerations may force some compromises. The GPM system offers the possibility of providing precipitation maps with much better time resolution than the monthly averages around which TRMM was planned, and therefore opens up new possibilities for hydrology and data assimilation into models. In this talk, methods that were developed for estimating sampling error in the rainfall averages that TRMM is providing will be used to estimate sampling error levels for GPM-era configurations. Possible impacts on GPM products of compromises in the sampling frequency will be discussed.

  7. Precipitation Recycling

    NASA Technical Reports Server (NTRS)

    Eltahir, Elfatih A. B.; Bras, Rafael L.

    1996-01-01

    The water cycle regulates and reflects natural variability in climate at the regional and global scales. Large-scale human activities that involve changes in land cover, such as tropical deforestation, are likely to modify climate through changes in the water cycle. In order to understand, and hopefully be able to predict, the extent of these potential global and regional changes, we need first to understand how the water cycle works. In the past, most of the research in hydrology focused on the land branch of the water cycle, with little attention given to the atmospheric branch. The study of precipitation recycling which is defined as the contribution of local evaporation to local precipitation, aims at understanding hydrologic processes in the atmospheric branch of the water cycle. Simply stated, any study on precipitation recycling is about how the atmospheric branch of the water cycle works, namely, what happens to water vapor molecules after they evaporate from the surface, and where will they precipitate?

  8. STRONTIUM PRECIPITATION

    DOEpatents

    McKenzie, T.R.

    1960-09-13

    A process is given for improving the precipitation of strontium from an aqueous phosphoric-acid-containing solution with nickel or cobalt ferrocyanide by simultaneously precipitating strontium or calcium phosphate. This is accomplished by adding to the ferrocyanide-containing solution calcium or strontium nitrate in a quantity to yield a concentration of from 0.004 to 0.03 and adjusting the pH of the solution to a value of above 8.

  9. MWRRET Value-Added Product: The Retrieval of Liquid Water Path and Precipitable Water Vapor from Microwave Radiometer (MWR) Datasets May 2009

    SciTech Connect

    Gaustad, KL; Turner, DD

    2009-05-30

    This report provides a short description of the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) microwave radiometer (MWR) RETrievel (MWRRET) value-added product (VAP) algorithm. This algorithm utilizes a complementary physical retrieval method and applies brightness temperature offsets to reduce spurious liquid water path (LWP) bias in clear skies resulting in significantly improved precipitable water vapor (PWV) and LWP retrievals. We present a general overview of the technique, input parameters, output products, and describe data quality checks. A more complete discussion of the theory and results is given in Turner et al. (2007b).

  10. MWRRET Value-Added Product: The Retrieval of Liquid Water Path and Precipitable Water Vapor from Microwave Radiometer (MWR) Data Sets (Revision 2)

    SciTech Connect

    Gaustad, KL; Turner, DD; McFarlane, SA

    2011-07-25

    This report provides a short description of the Atmospheric Radiation Measurement (ARM) Climate Research Facility microwave radiometer (MWR) Retrieval (MWRRET) value-added product (VAP) algorithm. This algorithm utilizes a complementary physical retrieval method and applies brightness temperature offsets to reduce spurious liquid water path (LWP) bias in clear skies resulting in significantly improved precipitable water vapor (PWV) and LWP retrievals. We present a general overview of the technique, input parameters, output products, and describe data quality checks. A more complete discussion of the theory and results is given in Turner et al. (2007b).

  11. Characterization of the Calcination Products of the Precipitates Obtained from the Bio-Oxidation with Thiobacillus Ferrooxidans of Sulphuric Water Pickling Liquors

    NASA Astrophysics Data System (ADS)

    Marco, J. F.; Gancedo, J. R.; López, F. A.

    1998-12-01

    The characterization of the calcination products of the precipitates obtained from the bio-oxidation with Thiobacillus ferrooxidans of sulphuric water pickling liquors has been carried out by means of Mössbauer spectroscopy, x-ray powder diffraction, infrared spectroscopy and transmission electron microscopy. The results show that a full transformation of the precipitates into α-Fe2O3 is achieved at temperatures higher than 850°C. Calcination at 700°C during two hours results in the formation of α-Fe2O3, ζ-Fe2O3 and Fe12O3(SO4)15. The Mössbauer parameters of ζ-Fe2O3 and Fe12O3(SO4)15 at 298 and 17K are reported.

  12. Production and Precipitation Hardening of Beta-Type Ti-35Nb-10Cu Alloy Foam for Implant Applications

    NASA Astrophysics Data System (ADS)

    Mutlu, Ilven; Yeniyol, Sinem; Oktay, Enver

    2016-04-01

    In this study, beta-type Ti-35Nb-10Cu alloy foams were produced by powder metallurgy method for dental implant applications. 35% Nb was added to stabilize the beta-Ti phase with low Young's modulus. Cu addition enhanced sinterability and gave precipitation hardening capacity to the alloy. Sintered specimens were precipitation hardened in order to enhance the mechanical properties. Electrochemical corrosion behavior of the specimens was examined by electrochemical impedance spectroscopy in artificial saliva. Electrochemical impedance spectroscopy results indicated that the oxide film on the surface of foam is a bi-layer structure consisting of outer porous layer and inner barrier layer. Impedance values of barrier layer were higher than porous layer. Corrosion resistance of specimens decreased at high fluoride concentrations and at low pH of artificial saliva. Corrosion resistance of alloys was slightly decreased with aging. Mechanical properties, microstructure, and surface roughness of the specimens were also examined.

  13. Statistical and Hydrological Evaluation of TRMM-Based Multi-Satellite Precipitation Analysis over the Wangchu Basin of Bhutan: Are the Latest Satellite Precipitation Products 3B42V7 Ready for Use in Ungauged Basins?

    NASA Technical Reports Server (NTRS)

    Xue, Xianwu; Hong, Yang; Limaye, Ashutosh S.; Gourley, Jonathan; Huffman, George J.; Khan, Sadiq Ibrahim; Dorji, Chhimi; Chen, Sheng

    2013-01-01

    The objective of this study is to quantitatively evaluate the successive Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) products and further to explore the improvements and error propagation of the latest 3B42V7 algorithm relative to its predecessor 3B42V6 using the Coupled Routing and Excess Storage (CREST) hydrologic model in the mountainous Wangchu Basin of Bhutan. First, the comparison to a decade-long (2001-2010) daily rain gauge dataset reveals that: 1) 3B42V7 generally improves upon 3B42V6s underestimation both for the whole basin (bias from -41.15 to -8.38) and for a 0.250.25 grid cell with high-density gauges (bias from -40.25 to 0.04), though with modest enhancement of correlation coefficients (CC) (from 0.36 to 0.40 for basin-wide and from 0.37 to 0.41 for grid); and 2) 3B42V7 also improves its occurrence frequency across the rain intensity spectrum. Using the CREST model that has been calibrated with rain gauge inputs, the 3B42V6-based simulation shows limited hydrologic prediction NSCE skill (0.23 in daily scale and 0.25 in monthly scale) while 3B42V7 performs fairly well (0.66 in daily scale and 0.77 in monthly scale), a comparable skill score with the gauge rainfall simulations. After recalibrating the model with the respective TMPA data, significant improvements are observed for 3B42V6 across all categories, but not as much enhancement for the already well-performing 3B42V7 except for a reduction in bias (from -26.98 to -4.81). In summary, the latest 3B42V7 algorithm reveals a significant upgrade from 3B42V6 both in precipitation accuracy (i.e., correcting the underestimation) thus improving its potential hydrological utility. Forcing the model with 3B42V7 rainfall yields comparable skill scores with in-situ gauges even without recalibration of the hydrological model by the satellite precipitation, a compensating approach often used but not favored by the hydrology community, particularly in ungauged basins.

  14. Towards stochastically downscaled precipitation in the Tropics based on a robust 1DD combined satellite product and a high resolution IR-based rain mask

    NASA Astrophysics Data System (ADS)

    Guilloteau, Clement; Roca, Rémy; Gosset, Marielle

    2015-04-01

    In the Tropics where the ground-based rain gauges network is very sparse, satellite rainfall estimates are becoming a compulsory source of information for various applications: hydrological modeling, water resources management or vegetation-monitoring. The tropical Tropical Amount of Precipitation with Estimate of Error (TAPEER) algorithm, developed within the framework of Megha-Tropiques satellite mission is a robust estimate of surface rainfall accumulations at the daily, one degree resolution. TAPEER validation in West Africa has proven its accuracy. Nevertheless applications that involve non-linear processes (such as surface runoff) require finer space / time resolution than one degree one day, or at least the statistical characterization of the sub-grid rainfall variability. TAPEER is based on a Universally Adjusted Global Precipitation Index (UAGPI) technique. The one degree, one day estimation relies on the combination of observations from microwave radiometers embarked on the 7 platforms forming the GPM constellation of low earth orbit satellites together with geostationary infra-red (GEO-IR) imagery. TAPEER provides as an intermediate product a high-resolution rain-mask based on the GEO-IR information (2.8 km, 15 min in Africa). The main question of this work is, how to use this high-resolution mask information as a constraint for downscaling ? This work first presents the multi-scale evaluation of TAPEER's rain detection mask against ground X-band polarimetric radar data and TRMM precipitation radar data in West Africa, through wavelet transform. Other algorithms (climate prediction center morphing technique CMORPH, global satellite mapping of precipitation GSMaP, multi-sensor precipitation estimate MPE) detection capabilities are also evaluated. Spatio-temporal wavelet filtering of the detection mask is then used to compute precipitation probability at the GEO-IR resolution. The wavelet tool is finally used to stochastically generate rain / no rain field

  15. Impact of Drought and Precipitation Seasonality on Net Primary Production and Plant Community Composition Across a Grassland Ecotone in New Mexico

    NASA Astrophysics Data System (ADS)

    Collins, S. L.; Thomey, M. L.; Brown, R. F.; Gehres, N.; Petrie, M. D.; Vanderbilt, K.; Pockman, W.

    2014-12-01

    In the southwestern US, climate change will impact the amount, timing and variability of rainfall during the summer monsoon. Changes in amount and seasonality of precipitation are likely to affect plant community dynamics and ecosystem processes, especially along ecotones. In 2012, we established a rainfall manipulation experiment (EDGE-Extreme Drought in Grasslands Experiment) in Chihuahuan Desert grassland (CDG) dominated by black grama and shortgrass steppe (SGS) dominated by blue grama across a grassland ecotone in central New Mexico. EDGE includes two rainfall treatments, chronic drought (~66% reduction in monsoon rainfall) and altered timing of the summer monsoon. Chronic drought is imposed from July through September by rainout shelters with roof panels that cover 66% of the surface area. To alter precipitation seasonality complete rainout shelters are erected in July and August, and all rainfall that occurred during this period is captured, stored, and then reapplied in several large rain events during September and October. Thus, this treatment receives the same amount of precipitation as ambient but differs in seasonality and frequency of rain events. We measured soil moisture, aboveground net primary production (ANPP), and plant species composition in each replicate (n=10) of each treatment at CDG and SGS sites. There were no significant pre-treatment differences in ANPP or plant species richness at either site. In 2013 following an above average monsoon, ambient ANPP was 99.4 g m-2 at CDG and 44.3 g m-2 at SGS. Event size reduction resulted in a 75% reduction in ANPP at CDG but only a 33% reduction in ANPP at SGS. Shifting the monsoon to later in the growing season resulted in a 50% and 43% reduction in ANPP at CDG and SGS, respectively. Thus, ANPP at CDG partially recovered from the mid-summer drought with late season precipitation but SGS did not. Event size reduction also resulted in a decrease in species richness at CDG, but not at SGS. These short

  16. Impact of drought and precipitation seasonality on net primary production and plant community composition across a grassland ecotone in New Mexico

    NASA Astrophysics Data System (ADS)

    Collins, Scott; Thomey, Michell; Brown, Renee; Gehres, Nate; Petrie, Matthew; Vanderbilt, Kristin; Pockman, William

    2015-04-01

    In the southwestern US, climate change will impact the amount, timing and variability of rainfall during the summer monsoon. Changes in amount and seasonality of precipitation are likely to affect plant community dynamics and ecosystem processes, especially along ecotones. In 2012, we established a rainfall manipulation experiment (EDGE-Extreme Drought in Grasslands Experiment) in Chihuahuan Desert grassland (CDG) dominated by black grama and shortgrass steppe (SGS) dominated by blue grama across a grassland ecotone in central New Mexico. EDGE includes two rainfall treatments, chronic drought (~66% reduction in monsoon rainfall) and altered timing of the summer monsoon. Chronic drought is imposed from July through September by rainout shelters with roof panels that cover 66% of the surface area. To alter precipitation seasonality complete rainout shelters are erected in July and August, and all rainfall that occurred during this period is captured, stored, and then reapplied in several large rain events during September and October. Thus, this treatment receives the same amount of precipitation as ambient but differs in seasonality and frequency of rain events. We measured soil moisture, aboveground net primary production (ANPP), and plant species composition in each replicate (n=10) of each treatment at CDG and SGS sites. There were no significant pre-treatment differences in ANPP or plant species richness at either site. In 2013 following an above average monsoon, ambient ANPP was 99.4 g m-2 at CDG and 44.3 g m-2 at SGS. Event size reduction resulted in a 75% reduction in ANPP at CDG but only a 33% reduction in ANPP at SGS. Shifting the monsoon to later in the growing season resulted in a 50% and 43% reduction in ANPP at CDG and SGS, respectively. Thus, ANPP at CDG partially recovered from the mid-summer drought with late season precipitation but SGS did not. Event size reduction also resulted in a decrease in species richness at CDG, but not at SGS. These short

  17. Precipitation Matters

    ERIC Educational Resources Information Center

    McDuffie, Thomas

    2007-01-01

    Although weather, including its role in the water cycle, is included in most elementary science programs, any further examination of raindrops and snowflakes is rare. Together rain and snow make up most of the precipitation that replenishes Earth's life-sustaining fresh water supply. When viewed individually, raindrops and snowflakes are quite…

  18. Validating NEXRAD MPE and Stage III precipitation products for uniform rainfall on the Upper Guadalupe River Basin of the Texas Hill Country

    NASA Astrophysics Data System (ADS)

    Wang, Xianwei; Xie, Hongjie; Sharif, Hatim; Zeitler, Jon

    2008-01-01

    SummaryThis study examines the performance of the Next Generation Weather Radar (NEXRAD) Multisensor Precipitation Estimator (MPE) and Stage III precipitation products, using a high-density rain gauge network located on the Upper Guadalupe River Basin of the Texas Hill Country. As point-area representativeness error of gauge rainfall is a major concern in assessment of radar rainfall estimation, this study develops a new method to automatically select uniform rainfall events based on coefficient of variation criterion of 3 by 3 radar cells. Only gauge observations of those uniform rainfall events are used as ground truth to evaluate radar rainfall estimation. This study proposes a new parameter probability of rain detection (POD) instead of the conditional probability of rain detection (CPOD) commonly used in previous studies to assess the capability that a radar or gauge detects rainfall. Results suggest that: (1) gauge observations of uniform rainfall better represent ground truth of a 4 × 4 km 2 radar cell than non-uniform rainfall; (2) the MPE has higher capability of rain detection than either gauge-only or Stage III; (3) the MPE has much higher linear correlation and lower mean relative difference with gauge measurements than the Stage III does; (4) the Stage III tends to overestimate precipitation (20%), but the MPE tends to underestimate (7%).

  19. Analysis of the Diurnal Cycle of Precipitation and its Relation to Cloud Radiative Forcing using TRMM Products

    NASA Technical Reports Server (NTRS)

    Randall, David A.; Fowler, Laura D.

    2000-01-01

    By incorporating the Tropical Rain Measuring Mission (TRMM) satellite orbital information into the geodesic version of the Colorado State University General Circulation Model (CSU GCM), we are able to fly a satellite in the GCM, and sample the simulated atmosphere in the same way as the TRMM sensors sample the real atmosphere. The TRMM sampling statistics of precipitation and radiative fluxes at annual, intraseasonal, monthly-mean and composited diurnal time scales are evaluated by comparing the satellite-sampled against fully-sampled simulated atmospheres. This information provides a valuable guidance for efficient usage of TRMM data and future satellite mission planning.

  20. Definition and impact of a quality index for radar-based reference measurements in the H-SAF precipitation product validation

    NASA Astrophysics Data System (ADS)

    Rinollo, A.; Vulpiani, G.; Puca, S.; Pagliara, P.; Kaňák, J.; Lábó, E.; Okon, L'.; Roulin, E.; Baguis, P.; Cattani, E.; Laviola, S.; Levizzani, V.

    2013-10-01

    The EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF) provides rainfall estimations based on infrared and microwave satellite sensors on board polar and geostationary satellites. The validation of these satellite estimations is performed by the H-SAF Precipitation Product Validation Group (PPVG). A common validation methodology has been defined inside the PPVG in order to make validation results from several institutes comparable and understandable. The validation of the PR-OBS-3 (blended infrared-microwave (IR-MW) instantaneous rainfall estimation) product using radar-based rainfall estimations as ground reference is described herein. A network of C-band and Ka-band radars throughout Europe ensures a wide area coverage with different orographic configurations and climatological regimes, but the definition of a quality control protocol for obtaining consistent ground precipitation fields across several countries is required. Among the hydro-meteorological community, the evaluation of the data quality is a quite consolidated practice, even though a unique definition of a common evaluation methodology between different countries and institutions has not been set up yet. Inside H-SAF, the first definition of the quality index of the radar rainfall observations has been introduced at the Italian Civil Protection Department (DPC). In the evaluation of the DPC quality index, several parameters are considered, some measured by the radar itself (static clutter map, range distance, radial velocity, texture of differential reflectivity, texture of co-polar correlation coefficient and texture of differential phase shift) and some obtained by external sources (digital elevation model, freezing layer height). In some cases, corrections were applied for clutter and beam blocking. The DPC quality index was calculated and applied to some relevant meteorological events reported by a radar test site in Italy. The precipitation

  1. Intercomparison of Total Atmospheric Precipitable Water Vapor Retrieval Products during the 2009 and 2010 CAPABLE Summer Intensives

    NASA Astrophysics Data System (ADS)

    Pippin, M. R.; Knepp, T. N.; Bedka, S.; Cowen, L.; Murray, J.; Deslover, D.; Feltz, W.; Yesalusky, M. A.; Smith, W.; Cede, A.; Abuhassan, N.; Herman, J. R.; Szykamn, J.

    2011-12-01

    In support of NASA's GEO-CAPE mission and Air Quality Applied Sciences, the Chemistry and Physics Atmospheric Boundary Layer Experiment (CAPABLE) site at NASA Langley Research Center has been established in coordination with Environmental Protection Agency (EPA) and Virginia Department of Environmental Quality (VA DEQ) to assess the relationship between high temporal resolution measurements from space and continuous in situ surface observations. During the 2009 and 2010 CAPABLE summer intensives, three methods for determining total atmospheric precipitable water vapor were utilized. Continuous total column measurements of water vapor were provided using a Pandora spectrometer, the DOE/NSTec Atmospheric Sounder Spectrometer for Infrared Spectral Technology (ASSIST) operated by the Hampton University and the University of Wisconsin Atmospheric Emitted Radiance Interferometer (AERI). Continuous meteorological parameters were measured on a 5m tower and rawinsondes were launched intermittently throughout both measurement periods. We present preliminary results of the intercomparison of total precipitable water vapor from the three instrumental methods and compare with estimated values from dew point temperature and satellite overpass data. Results from this study will have applications to satellite validation and Pandora retrieval algorithm development. Disclaimer: Although this work was reviewed by the U.S. Environmental Protection Agency and National Aeronautics and Space Administration, and approved for publication, it may not necessarily reflect official Agency policy.

  2. Multi-scale hydrologic applications of the latest satellite precipitation products in the Yangtze River basin using a distributed hydrological model

    NASA Astrophysics Data System (ADS)

    Li, Zhe; Yang, Dawen; Gao, Bing; Jiao, Yang; Hong, Yang; Xu, Tao

    2015-04-01

    The current era of satellite remote sensing has provided unprecedented opportunities for the monitoring and prediction of Earth's terrestrial hydrologic cycle. In the present study, we evaluated three global satellite precipitation products (3B42 V7, 3B42 RT and CMORPH) during 2003-2012 for multi-scale hydrological applications, including annual water budgeting, monthly and daily streamflow simulation, and extreme floods modeling, via a distributed hydrological model (GBHM) in the Yangtze River basin. This regional evaluation is first performed at temporal scales ranging from annual to daily, based on a number of diagnostic statistics, providing useful information on the error characteristics associated with the three satellite precipitation products. Then the work, with an application-oriented view, focuses on the modeling-based evaluation of the three products. The results show 3B42 V7 data generally has a better performance in annual water budgeting and monthly streamflow simulation, but this superiority is not guaranteed for daily simulation, especially for floods monitoring. It is also found that, for annual water budgeting, the positive (negative) bias of 3B42 RT (CMORPH) estimates have been mainly propagated into the simulated runoff, while the simulated evapotranspiration tends to be more sensitive to negative bias. Regarding streamflow simulation, both near-real-time products show region-dependent bias: 3B42 RT tends to overestimate streamflow in the upper Yangtze River; in contrast, CMORPH shows serious underestimation in those downstream sub-basins, while it is able to effectively monitor streamflow into the Three Gorges Reservoir. With 394 selected flood events, the results indicate that 3B42 RT and CMORPH have competitive performances for near real-time floods monitoring in the upper Yangtze, but for those downstream sub-basins, 3B42 RT performs better than CMORPH. Furthermore, the inability of all satellite products to capture some key features of the

  3. Global Precipitation Measurement (GPM) Mission Products and Services at the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC)

    NASA Technical Reports Server (NTRS)

    Liu, Zhong; Ostrenga, D.; Vollmer, B.; Deshong, B.; Greene, M.; Teng, W.; Kempler, S. J.

    2015-01-01

    On February 27, 2014, the NASA Global Precipitation Measurement (GPM) mission was launched to provide the next-generation global observations of rain and snow (http:pmm.nasa.govGPM). The GPM mission consists of an international network of satellites in which a GPM Core Observatory satellite carries both active and passive microwave instruments to measure precipitation and serve as a reference standard, to unify precipitation measurements from a constellation of other research and operational satellites. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data within the NASA Earth Observation System Data Information System (EOSDIS). The GES DISC is home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). Over the past 16 years, the GES DISC has served the scientific as well as other communities with TRMM data and user-friendly services. During the GPM era, the GES DISC will continue to provide user-friendly data services and customer support to users around the world. GPM products currently and to-be available include the following: 1. Level-1 GPM Microwave Imager (GMI) and partner radiometer products. 2. Goddard Profiling Algorithm (GPROF) GMI and partner products. 3. Integrated Multi-satellitE Retrievals for GPM (IMERG) products. (early, late, and final)A dedicated Web portal (including user guides, etc.) has been developed for GPM data (http:disc.sci.gsfc.nasa.govgpm). Data services that are currently and to-be available include Google-like Mirador (http:mirador.gsfc.nasa.gov) for data search and access; data access through various Web services (e.g., OPeNDAP, GDS, WMS, WCS); conversion into various formats (e.g., netCDF, HDF, KML (for Google Earth), ASCII); exploration, visualization, and statistical online analysis through Giovanni (http:giovanni.gsfc.nasa.gov); generation of value-added products; parameter and spatial subsetting; time aggregation; regridding; data

  4. Global Precipitation Measurement (GPM) Mission Products and Services at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC)

    NASA Technical Reports Server (NTRS)

    Ostrenga, D.; Liu, Z.; Vollmer, B.; Teng, W.; Kempler, S.

    2014-01-01

    On February 27, 2014, the NASA Global Precipitation Measurement (GPM) mission was launched to provide the next-generation global observations of rain and snow (http:pmm.nasa.govGPM). The GPM mission consists of an international network of satellites in which a GPM Core Observatory satellite carries both active and passive microwave instruments to measure precipitation and serve as a reference standard, to unify precipitation measurements from a constellation of other research and operational satellites. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data within the NASA Earth Observation System Data Information System (EOSDIS). The GES DISC is home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). Over the past 16 years, the GES DISC has served the scientific as well as other communities with TRMM data and user-friendly services. During the GPM era, the GES DISC will continue to provide user-friendly data services and customer support to users around the world. GPM products currently and to-be available include the following:Level-1 GPM Microwave Imager (GMI) and partner radiometer productsLevel-2 Goddard Profiling Algorithm (GPROF) GMI and partner productsLevel-3 daily and monthly productsIntegrated Multi-satellitE Retrievals for GPM (IMERG) products (early, late, and final) A dedicated Web portal (including user guides, etc.) has been developed for GPM data (http:disc.sci.gsfc.nasa.govgpm). Data services that are currently and to-be available include Google-like Mirador (http:mirador.gsfc.nasa.gov) for data search and access; data access through various Web services (e.g., OPeNDAP, GDS, WMS, WCS); conversion into various formats (e.g., netCDF, HDF, KML (for Google Earth), ASCII); exploration, visualization, and statistical online analysis through Giovanni (http:giovanni.gsfc.nasa.gov); generation of value-added products; parameter and spatial subsetting; time

  5. Global Precipitation Measurement (GPM) Mission Products and Services at the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC)

    NASA Astrophysics Data System (ADS)

    Ostrenga, D.; Liu, Z.; Vollmer, B.; Teng, W. L.; Kempler, S. J.

    2014-12-01

    On February 27, 2014, the NASA Global Precipitation Measurement (GPM) mission was launched to provide the next-generation global observations of rain and snow (http://pmm.nasa.gov/GPM). The GPM mission consists of an international network of satellites in which a GPM "Core Observatory" satellite carries both active and passive microwave instruments to measure precipitation and serve as a reference standard, to unify precipitation measurements from a constellation of other research and operational satellites. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data within the NASA Earth Observation System Data Information System (EOSDIS). The GES DISC is home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). Over the past 16 years, the GES DISC has served the scientific as well as other communities with TRMM data and user-friendly services. During the GPM era, the GES DISC will continue to provide user-friendly data services and customer support to users around the world. GPM products currently and to-be available include the following: Level-1 GPM Microwave Imager (GMI) and partner radiometer products Goddard Profiling Algorithm (GPROF) GMI and partner products Integrated Multi-satellitE Retrievals for GPM (IMERG) products (early, late, and final) A dedicated Web portal (including user guides, etc.) has been developed for GPM data (http://disc.sci.gsfc.nasa.gov/gpm). Data services that are currently and to-be available include Google-like Mirador (http://mirador.gsfc.nasa.gov/) for data search and access; data access through various Web services (e.g., OPeNDAP, GDS, WMS, WCS); conversion into various formats (e.g., netCDF, HDF, KML (for Google Earth), ASCII); exploration, visualization, and statistical online analysis through Giovanni (http://giovanni.gsfc.nasa.gov); generation of value-added products; parameter and spatial subsetting; time aggregation; regridding

  6. Modeling the effects of N deposition, precipitation variability, and soil texture on winter annual production and fire risk in Southern California deserts

    NASA Astrophysics Data System (ADS)

    Rao, L. E.; Allen, E. B.; Meixner, T.

    2008-12-01

    Fire risk in deserts is increased by high production of annual grasses and forbs that create a continuous fine fuel bed in the interspaces between shrubs. Interspace production is influenced by many factors including water and N availability and soil texture, and so the DayCent model was used to investigate how production of herbaceous annuals change along gradients of these production-forcing factors. DayCent was calibrated on the interspace vegetation from a creosote bush scrub site in Joshua Tree National Park and validated on a second creosote site within the Park with different soils and climate. The DayCent model was well calibrated on the first site, but validation on the second site showed that the model is sensitive to soil clay content such that soils with low clay contents lose soil C and N during model equilibration. Despite discrepancies between modeled and observed soil C and N pools, relative response of production to N fertilization was well represented by the model. Thus, DayCent can be used to determine conservative estimates of fire risk in the desert under increased precipitation and N deposition. Fire risk simulations indicate that interspace vegetation is strongly limited by water availability when mean annual precipitation is less than 21 cm yr-1. Under simulated N deposition of 8 kg-N ha-1, approximating the most polluted regions in these deserts, fire risk increases to 62-76% under a range of soil textures indicating that under increased N deposition fire risk is high in years of average to above-average rainfall.

  7. Comparison of NEXRAD Stage III and MPE precipitation products with constraints from high quality and density of raingauge networks in the Upper Guadalupe River Basin, Central Texas

    NASA Astrophysics Data System (ADS)

    Xie, H.; Wang, X.

    2006-05-01

    NEXRAD's Multisensor Precipitation Estimator (MPE) product replaced the Stage III product started in October 2003 at the West Gulf River Forecast Center (WGRFC) where includes most of the Texas and New Mexico. The MPE is an integrated product of rain gauge, NEXRAD, and satellite (GOES) precipitation estimates. The main objective of MPE is to reduce both areal-mean bias error and local bias error. The overall improved quality of MPE over Stage 3 is evident at the WGRFC. However, so far, there is no quantitative evaluation in a relative long period (one year or more) of a large area. In this study, high quality and density of 50 raingauge networks (6 minutes temporal resolution) in the Upper Guadalupe River Basin, Central Texas are used to evaluate both the Stage III (years 2001 and 2002) and MPE (year 2004) products. In this study, we propose two types of comparison (1) directly compare collocated radar cell and gauge of all rainfall events and (2) only compare collocated radar cell and gauge of homogeneous/uniform rainfall events. To find uniform rainfall events, 6-mintutes raingauge rainfall were used to calculate the correlation coefficient (CC) and coefficient of variation (CV) of a hour among one central gauge and its surrounding gauges (>= 4). For a particular rainfall hour, when CV is < 0.5 and CC is > 0.5, or CV is <0.1, the rainfall event of this hour is thus selected as a uniform or homogeneous rainfall event. Our preliminary results of CC from all rainfall events and homogeneous rainfall events for year 2004 (MPE) are 0.79 and 0.96, respectively. This indicates an overall good quality of MPE product in comparison with raingauge rainfall, especially for the homogeneous rainfall events. Work is in progress.

  8. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  9. The Global Precipitation Climatology Project (GPCP) Combined Precipitation Dataset

    NASA Technical Reports Server (NTRS)

    Huffman, George J.; Adler, Robert F.; Arkin, Philip; Chang, Alfred; Ferraro, Ralph; Gruber, Arnold; Janowiak, John; McNab, Alan; Rudolf, Bruno; Schneider, Udo

    1997-01-01

    The Global Precipitation Climatology Project (GPCP) has released the GPCP Version 1 Combined Precipitation Data Set, a global, monthly precipitation dataset covering the period July 1987 through December 1995. The primary product in the dataset is a merged analysis incorporating precipitation estimates from low-orbit-satellite microwave data, geosynchronous-orbit -satellite infrared data, and rain gauge observations. The dataset also contains the individual input fields, a combination of the microwave and infrared satellite estimates, and error estimates for each field. The data are provided on 2.5 deg x 2.5 deg latitude-longitude global grids. Preliminary analyses show general agreement with prior studies of global precipitation and extends prior studies of El Nino-Southern Oscillation precipitation patterns. At the regional scale there are systematic differences with standard climatologies.

  10. Trends of temperature and precipitation and their impact on grapewine phenology and production of in a Mediterranean vineyard region of Northeastern Spain

    NASA Astrophysics Data System (ADS)

    Ramos, M. C.; Jones, G. V.; Martínez-Casasnovas, J. A.

    2009-04-01

    The present analysis tries to contribute to the knowledge and impacts of climate change on agriculture, in particular in dryland areas of the Mediterranean NE Spain. The analysis was carried out in the Penedès region, located in Northeastern Spain (Barcelona province). In this area, vineyards have cultivated for centuries and at present represent about 80% of the cultivated area, most of them as rainfed agriculture, without irrigation. In order to analyse climate change impacts on grape development and production, the trends of daily rainfall and temperature were analyzed for the whole year and for the growing season, as well as some bioclimatic indexes (Hugling and Winkler index) using a long data set belonging to Vilafranca del Penedès for the period 1952-2006, and shorter series belonging to the observatories of Sant Sadurní d'Anoia, Sant Martí Sarroca, Els Hostalest de Pierola for the last 12 years (1996-2007). Phenology dates and production for the last 12 years for the main varieties cultivated in the area (Macabeo, Xarello, Parellada and Chardonnay) were analysed in relation to all the climatic analysed parameters. The study revealed warming trends with higher increases in the maximum temperatures (0.04°C/year) than in the minimum temperatures (0.03°C/year), and a significant increase in the number of days with temperatures higher than 30°C (0.43 days/year). Changes were also reproduced during the grape growing season. The increase of temperature has its influence on higher evapotranspiration ratios, which implies less effective water for crop development. Annual rainfall showed high variability from year to year and did not change significantly with time not at annual level either during the growing season. However, the precipitation of the main rainfall periods (spring and autumn) shows opposite trends, decreasing precipitation in spring and increasing in autumn. According to the vine phenological stages a significant decrease of precipitation

  11. Generation of dose-response relationships to assess the effects of acidity in precipitation on growth and productivity of vegetation

    SciTech Connect

    Evans, L.S.

    1981-01-01

    Experiments were performed with several plant species in natural environments as well in a greenhouse and/or tissue culture facilities to establish dose-response functions of plant responses to simulated acidic rain in order to determine environmental risk assessments to ambient levels of acidic rain. Response functions of foliar injury, biomass of leaves and seed of soybean and pinto beans, root yields of radishes and garden beets, and reproduction of bracken fern are considered. The dose-response function of soybean seed yields with the hydrogen ion concentration of simulated acidic rainfalls was expressed by the equation y = 21.06-1.01 log x where y = seed yield in grams per plant and x = the hydrogen concentration if ..mu..eq l/sup -1/. The correlation coefficient of this relationship was -0.90. A similar dose-response function was generated for percent fertilization of ferns in a forest understory. When percent fertilization is plotted on logarithmic scale with hydrogen ion concentration of the simulated rain solution, the Y intercept is 51.18, slope -0.041 with a correlation coefficient of -0.98. Other dose-response functions were generated that assist in a general knowledge as to which plant species and which physiological processes are most impacted by acidic precipitation. Some responses did not produce convenient dose-response relationships. In such cases the responses may be altered by other environmental factors or there may be no differences among treatment means.

  12. An Ecoinformatic Analysis of the Effect of Seasonal and Annual Variation in Temperature, Precipitation, and Solar Irradiance on Pollen Productivity in Two Neotropical Forests

    NASA Astrophysics Data System (ADS)

    Haselhorst, D. S.; Tcheng, D. K.; Moreno, J. E.; Punyasena, S. W.

    2014-12-01

    Observational data provide a powerful source of information for understanding the phenological response of tropical forests to a changing climate. Annual changes in mean temperature, precipitation, and solar irradiance, in part driven by ENSO cycles, provide a natural experiment. However, these time series are often relatively short (several years to several decades), the average climatic variability experienced in that timeframe is relatively small, and the corresponding response is therefore often very weak. As a result, standard statistical approaches may fail in detecting a biological response. We present an alternative ecoinformatic analysis that demonstrates the power of weak models in the discovery and interpretation of statistically significant signals in short, noisy, ecological time series. We developed a simple response prediction model that uses cross-validation to explore a landscape of models that correlate the phenological behavior of individual taxa (pollen production, flowering, fruiting) to seasonal and annual mean temperature, precipitation, and solar irradiance using multivariate linear regression. We use a sign slope sensitivity analysis of each linear model that tallies positive and negative slope counts of a taxon's phenological behavior to our environmental and null variables. We applied this analysis to pollen trap data collected from 1996 to 2006 from two lowland Panamanian forests, Barro Colorado Island and Parque National San Lorenzo. We also tested the performance of our predictive model using published data of annual flowering and fruiting from BCI to corroborate that our approach could reproduce previously published results on tropical phenology. Our results indicate that although the overall variation in temperature was 3.28 °C over the ten year period, pollen productivity at both sites was most consistently affected by changes in temperature. This result was replicated by the published BCI flower and fruit data, which also

  13. NOx production due to energetic particle precipitation in the MLT region - results from an ion-chemistry model

    NASA Astrophysics Data System (ADS)

    Nieder, Holger; Sinnhuber, Miriam

    2013-04-01

    The chemistry in the mesosphere/lower thermosphere (MLT) region is driven by forcing from solar radiation and energetic particles. The resulting ionisation, dissociation and excitation of the constituents lead to production of neutral reactive species such as NOx (N, NO, NO2) and HOx (H, OH, HO2), both directly from dissociation of neutrals and indirectly from subsequent ion-neutral reactions. As NOx is long-lived during polar winter, it can be transported down to the stratosphere and contribute to catalytic ozone depletion. To study the effective NOx production rates during an ionisation event, runs with a one-dimensional state-of-the-art ion chemistry model (UBIC) are carried out and analysed. The model starts with a neutral atmosphere and uses direct ion and neutral production rates from Porter et al. (1976) and Rusch et al. (1981), adapted for the MLT region. Including raw ionisation rates from external sources such as AIMOS is possible. The ion-neutral reactions in the charged atmosphere are computed until equilibrium is reached, resulting in an effective production rate including impact of ion-neutral reactions. The indirect NOx production rate is found to depend on atmospheric parameters such as pressure, temperature and the abundance of NOx, atomic oxygen and H2O. For the MLT region, this leads to an increasing amount of NOx per ionpair created with increasing altitude due to an increasing atomic oxygen VMR. Values of >1.8 NOx per ionpair can be obtained. The results are made available to a 3D Chemistry Transport Model using a database-approach and multilinear interpolation for readout. Efficiency of this approach and first results from a 3D CTM using the ion-chemistry results are discussed.

  14. METHOD FOR REMOVING CONTAMINATION FROM PRECIPITATES

    DOEpatents

    Stahl, G.W.

    1959-01-01

    An improvement in the bismuth phosphate carrier precipitation process is presented for the recovery and purification of plutonium. When plutonium, in the tetravalent state, is carried on a bismuth phosphate precipitate, amounts of centain of the fission products are carried along with the plutonium. The improvement consists in washing such fission product contaminated preeipitates with an aqueous solution of ammonium hydrogen fluoride. since this solution has been found to be uniquely effective in washing fission production contamination from the bismuth phosphate precipitate.

  15. Evaluation of 2B31 TRMM-product rain estimates for single precipitation events over a region with complex topographic features

    NASA Astrophysics Data System (ADS)

    Montero-MartíNez, Guillermo; Zarraluqui-Such, VíCtor; GarcíA-GarcíA, Fernando

    2012-01-01

    An evaluation of precipitation estimations on the ground for individual rainfall events was carried out by comparing the 2B31 Tropical Rainfall Measuring Mission (TRMM) product versus a high-density, rain gauge network deployed at the ground over a small (about 1000 km2) study area in a continental region characterized by complex topography and high altitude. This comparison, using categorical analysis, showed a good agreement for several skill parameters most frequently used in works of this type. In this paper, it is concluded that Odds Ratio Skill Score (ORSS) is a more reliable measure of skill for categorical statistics than other scores because it better reflects the agreement between the two data sets. Furthermore, ORSS allows one to test the significance of the results so it is possible to discriminate whether the resulting skill is due to pure chance (ORSS was significant in 70% of the cases studied). Although variance and mean analyses generally showed differences between data sets for both the amount and the distribution of rainfall rate over the study area, least squares fits indicate a very high and quite linear correlation for both the mean rainfall rate (r2 = 0.90) and the maximum amount of precipitation at a given point (r2 = 0.74). It is concluded that 2B31 TRMM data can be used in weather applications for the area studied here and others with complex orographical characteristics and also as a tool in the diagnosis of individual rain events in other regions where there are no other data sources available.

  16. Production of a novel bioflocculant MNXY1 by Klebsiella pneumoniae strain NY1 and application in precipitation of cyanobacteria and municipal wastewater treatment

    PubMed Central

    Nie, M.; Yin, X.; Jia, J.; Wang, Y.; Liu, S.; Shen, Q.; Li, P.; Wang, Z.

    2015-01-01

    Aims To isolate and characterize the novel bioflocculant-producing bacteria, to optimize the bioflocculant production and evaluate its potential applications. Methods and Results Klebsiella pneumoniae strain NY1, a bacterium that produces a novel bioflocculant (MNXY1), was selected on the chemically defined media. It was classified according to the 16S rRNA gene sequence, morphological and microscopic characteristics. MNXY1 was characterized to contain 26% protein and 66% total sugar. The constituent sugar monomers of MNXY1, revealed by NMR analysis, are glucose, galactose and quinovose. Favorable culture conditions for MNXY1 production were determined. Strain NY1 produces a high level (14.9 g l−1) of MNXY1. MNXY1 is thermostable and tolerant to the extreme pH. It precipitated 54% of cyanobacteria from laboratory culture and 72% of the total suspended solids from raw wastewater. Conclusions Strain NY1 was identified to produce a novel bioflocculant MNXY1. The outstanding performance of MNXY1 in practical applications and its availability in copious amounts make it attractive for further investigation and development for industrial scale applications. PMID:21679283

  17. Observation-Corrected Precipitation Estimates in GEOS-5

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; Liu, Qing

    2014-01-01

    Several GEOS-5 applications, including the GEOS-5 seasonal forecasting system and the MERRA-Land data product, rely on global precipitation data that have been corrected with satellite and or gauge-based precipitation observations. This document describes the methodology used to generate the corrected precipitation estimates and their use in GEOS-5 applications. The corrected precipitation estimates are derived by disaggregating publicly available, observationally based, global precipitation products from daily or pentad totals to hourly accumulations using background precipitation estimates from the GEOS-5 atmospheric data assimilation system. Depending on the specific combination of the observational precipitation product and the GEOS-5 background estimates, the observational product may also be downscaled in space. The resulting corrected precipitation data product is at the finer temporal and spatial resolution of the GEOS-5 background and matches the observed precipitation at the coarser scale of the observational product, separately for each day (or pentad) and each grid cell.

  18. Analysis of Multiple Precipitation Products and Preliminary Assessment of Their Impact on Global Land Data Assimilation System (GLDAS) Land Surface States

    NASA Technical Reports Server (NTRS)

    Gottschalck, Jon; Meng, Jesse; Rodel, Matt; Houser, paul

    2005-01-01

    Land surface models (LSMs) are computer programs, similar to weather and climate prediction models, which simulate the stocks and fluxes of water (including soil moisture, snow, evaporation, and runoff) and energy (including the temperature of and sensible heat released from the soil) after they arrive on the land surface as precipitation and sunlight. It is not currently possible to measure all of the variables of interest everywhere on Earth with sufficient accuracy and space-time resolution. Hence LSMs have been developed to integrate the available observations with our understanding of the physical processes involved, using powerful computers, in order to map these stocks and fluxes as they change in time. The maps are used to improve weather forecasts, support water resources and agricultural applications, and study the Earth's water cycle and climate variability. NASA's Global Land Data Assimilation System (GLDAS) project facilitates testing of several different LSMs with a variety of input datasets (e.g., precipitation, plant type). Precipitation is arguably the most important input to LSMs. Many precipitation datasets have been produced using satellite and rain gauge observations and weather forecast models. In this study, seven different global precipitation datasets were evaluated over the United States, where dense rain gauge networks contribute to reliable precipitation maps. We then used the seven datasets as inputs to GLDAS simulations, so that we could diagnose their impacts on output stocks and fluxes of water. In terms of totals, the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) had the closest agreement with the US rain gauge dataset for all seasons except winter. The CMAP precipitation was also the most closely correlated in time with the rain gauge data during spring, fall, and winter, while the satellitebased estimates performed best in summer. The GLDAS simulations revealed that modeled soil moisture is highly

  19. Experimental Warming and Precipitation Effects on Plant Community Composition, Productivity, Nutrient Availability, and Soil Respiration in Pacific Northwest Prairies along a Natural Climate Gradient

    NASA Astrophysics Data System (ADS)

    Bridgham, S. D.; Pfeifer-Meister, L.; Tomaszewski, T.; Reynolds, L.; Goklany, M.; Wilson, H.; Johnson, B. R.

    2011-12-01

    Climate change effects on soil respiration and carbon stores in grasslands globally may have significant implications for future atmospheric carbon dioxide concentrations. Climate change may also may negatively impact native plant species and favor exotic species. We are experimentally increasing temperature by 3 degrees C and increasing precipitation by 25% above ambient in three upland prairie sites along a natural climate gradient from southwestern Oregon to central-western Washington to determine how future climate change will affect (i) plant community composition and the relative success of native versus introduced plant species and (ii) above- and belowground carbon and nutrient dynamics. Sixty plots (20 at each site) were restored by mowing, raking, and herbicide application followed by the sowing of the same 34 native grass and forb species in each plot. Differences in total cover, net primary productivity, and community composition were much greater among sites than among treatments within sites in both 2010--the establishment year, and 2011-the first full year of treatment. Strong successional dynamics occurred over the two years as competition intensified, but these were dependent on a site-treatment interaction, with lower native plant survival in heated plots because of competitive exclusion by exotic, invasive plants. A strong treatment - season interaction in canopy cover (as determined by canopy reflectance) also occurred, with heating causing greater cover during the wet season and lower cover during the dry season. This effect was strongest in the southernmost site which experiences earlier and more intense drought conditions. There were also strong site, treatment, and season interactions on nutrient availability as determined by cation-anion exchange resins. Heating increased nutrient availability in all but the northernmost site during the growing season, and that site also had much lower nutrient availability, but overall availability and

  20. PRECIPITATION OF PLUTONOUS PEROXIDE

    DOEpatents

    Barrick, J.G.; Manion, J.P.

    1961-08-15

    A precipitation process for recovering plutonium values contained in an aqueous solution is described. In the process for precipitating plutonium as plutonous peroxide, hydroxylamine or hydrazine is added to the plutoniumcontaining solution prior to the addition of peroxide to precipitate plutonium. The addition of hydroxylamine or hydrazine increases the amount of plutonium precipitated as plutonous peroxide. (AEC)

  1. Microbial production of isotopically light iron(II) in a modern chemically precipitated sediment and implications for isotopic variations in ancient rocks

    USGS Publications Warehouse

    Tangalos, G.E.; Beard, B.L.; Johnson, C.M.; Alpers, C.N.; Shelobolina, E.S.; Xu, H.; Konishi, H.; Roden, E.E.

    2012-01-01

    The inventories and Fe isotope composition of aqueous Fe(II) and solid-phase Fe compounds were quantified in neutral-pH, chemically precipitated sediments downstream of the Iron Mountain acid mine drainage site in northern California, USA. The sediments contain high concentrations of amorphous Fe(III) oxyhydroxides [Fe(III)am] that allow dissimilatory iron reduction (DIR) to predominate over Fe–S interactions in Fe redox transformation, as indicated by the very low abundance of Cr(II)-extractable reduced inorganic sulfur compared with dilute HCl-extractable Fe. δ56Fe values for bulk HCl- and HF-extractable Fe were ≈ 0. These near-zero bulk δ56Fe values, together with the very low abundance of dissolved Fe in the overlying water column, suggest that the pyrite Fe source had near-zero δ56Fe values, and that complete oxidation of Fe(II) took place prior to deposition of the Fe(III) oxide-rich sediment. Sediment core analyses and incubation experiments demonstrated the production of millimolar quantities of isotopically light (δ56Fe ≈ -1.5 to -0.5‰) aqueous Fe(II) coupled to partial reduction of Fe(III)am by DIR. Trends in the Fe isotope composition of solid-associated Fe(II) and residual Fe(III)am are consistent with experiments with synthetic Fe(III) oxides, and collectively suggest an equilibrium Fe isotope fractionation between aqueous Fe(II) and Fe(III)am of approximately -2‰. These Fe(III) oxide-rich sediments provide a model for early diagenetic processes that are likely to have taken place in Archean and Paleoproterozoic marine sediments that served as precursors for banded iron formations. Our results suggest pathways whereby DIR could have led to the formation of large quantities of low-δ56Fe minerals during BIF genesis.

  2. DISSOLUTION OF PLUTONIUM CONTAINING CARRIER PRECIPITATE BY CARBONATE METATHESIS AND SEPARATION OF SULFIDE IMPURITIES THEREFROM BY SULFIDE PRECIPITATION

    DOEpatents

    Duffield, R.B.

    1959-07-14

    A process is described for recovering plutonium from foreign products wherein a carrier precipitate of lanthanum fluoride containing plutonium is obtained and includes the steps of dissolving the carrier precipitate in an alkali metal carbonate solution, adding a soluble sulfide, separating the sulfide precipitate, adding an alkali metal hydroxide, separating the resulting precipitate, washing, and dissolving in a strong acid.

  3. Estimating Global Precipitation for Science and Application

    NASA Technical Reports Server (NTRS)

    Huffman, George J.

    2013-01-01

    Over the past two decades there has been vigorous development in the satellite assets and the algorithms necessary to estimate precipitation around the globe. In particular the highly successful joint NASAJAXA Tropical Rainfall Measuring Mission (TRMM) and the upcoming Global Precipitation Measurement (GPM) mission, also joint between NASA and JAXA, have driven these issues. At the same time, the long-running Global Precipitation Climatology Project (GPCP) continues to extend a stable, climate-oriented view of global precipitation. This talk will provide an overview of these projects and the wider international community of precipitation datasets, sketch plans for next-generation products, and provide some examples of the best use for the different products. One key lesson learned is that different data sets are needed to address the variety of issues that need precipitation data, including detailed 3-D views of hurricanes, flash flood forecasting, drought analysis, and global change.

  4. Global Precipitation Measurement (GPM) implementation

    NASA Astrophysics Data System (ADS)

    Neeck, Steven P.; Kakar, Ramesh K.; Azarbarzin, Ardeshir A.; Hou, Arthur Y.

    2010-10-01

    The Global Precipitation Measurement (GPM) mission will provide enhanced space-based precipitation measurements with sufficient coverage, spatial resolution, temporal sampling, retrieval accuracy, and microphysical information to advance the understanding of Earth's water and energy cycle and to improve predictions of its climate, weather, and hydrometeorological processes. Such improvements will in turn improve decision support systems in broad societal applications (e.g. water resource management, agriculture, transportation, etc). GPM is a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA), building upon their highly successful partnership on the Tropical Rainfall Measuring Mission (TRMM). The GPM architecture consists of NASA satellites operating in partnership with other earth-observing satellites and instruments to produce global precipitation science data. The current generation of multi-satellite global precipitation products based on microwave/infrared sensors from uncoordinated satellite missions has for its anchor the TRMM precipitation radar and the TRMM Microwave Imager measurements over the tropics and subtropics (+/- 35 degrees latitude), with a mean sampling time of approximately 17 hours. The GPM mission will deploy a spaceborne Core Observatory as a reference standard to unify a space constellation of research and operational microwave sensors aimed at providing uniformly calibrated precipitation measurements globally every 2-4 hours. The Core Observatory measurements will provide, for the first time, quantitative information on precipitation particle size distribution needed for improving the accuracy of precipitation estimates by microwave radiometers and radars. In addition, the GPM will also include a second microwave radiometer and a Tracking and Data Relay Satellite (TDRS) communications subsystem for near real time data relay for a future partner-provided constellation satellite. This second GPM Microwave Imager (GMI

  5. Electrostatic Precipitator (ESP) TRAINING MANUAL

    EPA Science Inventory

    The manual assists engineers in using a computer program, the ESPVI 4.0W, that models all elements of an electrostatic precipitator (ESP). The program is a product of the Electric Power Research Institute and runs in the Windows environment. Once an ESP is accurately modeled, the...

  6. Precipitation Climate Data Records

    NASA Astrophysics Data System (ADS)

    Nelson, B. R.; Prat, O.; Vasquez, L.

    2015-12-01

    Five precipitation CDRs are now or soon will be transitioned to NOAA's CDR program. These include the PERSIANN data set, which is a 30-year record of daily adjusted global precipitation based on retrievals from satellite microwave data using artificial neural networks. The AMSU-A/B/Hydrobundle is an 11-year record of precipitable water, cloud water, ice water, and other variables. CMORPH (the NOAA Climate Prediction Center Morphing Technique) is a 17-year record of daily and sub-daily adjusted global precipitation measured from passive microwave and infrared data at high spatial and temporal resolution. GPCP (the Global Precipitation Climatology Project) is an approximately 30-year record of monthly and pentad adjusted global precipitation and a 17-year record of daily adjusted global precipitation. The NEXRAD Reanalysis is a 10-year record of high resolution NEXRAD radar based adjusted CONUS-wide hourly and daily precipitation. This study provides an assessment of the existing and transitioned long term precipitation CDRs and includes the verification of the five precipitation CDRs using various methods including comparison with in-situ data sets and trend analysis. As all of the precipitation related CDRs are transitioned, long term analyses can be performed. Comparisons at varying scales (hourly, daily and longer) of the precipitation CDRs with in-situ data sets are provided as well as a first look at what could be an ensemble long term precipitation data record.

  7. Application of quantitative precipitation forecasting and precipitation ensemble prediction for hydrological forecasting

    NASA Astrophysics Data System (ADS)

    Tao, P.; Tie-Yuan, S.; Zhi-Yuan, Y.; Jun-Chao, W.

    2015-05-01

    The precipitation in the forecast period influences flood forecasting precision, due to the uncertainty of the input to the hydrological model. Taking the ZhangHe basin as the example, the research adopts the precipitation forecast and ensemble precipitation forecast product of the AREM model, uses the Xin Anjiang hydrological model, and tests the flood forecasts. The results show that the flood forecast result can be clearly improved when considering precipitation during the forecast period. Hydrological forecast based on Ensemble Precipitation prediction gives better hydrological forecast information, better satisfying the need for risk information for flood prevention and disaster reduction, and has broad development opportunities.

  8. Controlling and engineering precipitation patterns.

    PubMed

    Lagzi, István

    2012-02-21

    Controlling and engineering chemical structures are the most important scientific challenges in material science. Precipitation patterns from ions or nanoparticles are promising candidates for designing bulk structure for catalysis, energy production, storage, and electronics. There are only a few procedures and techniques to control precipitation (Liesegang) patterns in gel media (e.g., using an electric field, varying the initial concentration of the electrolytes). However, those methods provide just a limited degree of freedom. Here, we provide a robust and transparent way to control and engineer Liesegang patterns by varying gel concentration and inducing impurity by addition of gelatin to agarose gel. Using this experimental method, different precipitation structures can be obtained with different width and spatial distribution of the formed bands. A new variant of a sol-coagulation model was developed to describe and understand the effect of the gel concentration and impurities on Liesegang pattern formation. PMID:22283626

  9. Observation of solid precipitation using satellite gravity

    NASA Astrophysics Data System (ADS)

    Seo, K.; Waliser, D. E.; Ryu, D.; Tian, B.; Kim, B.

    2009-12-01

    Understanding hydrological processes in the arctic region and their variation are emerging and important issues in the association with global climate changes. Solid precipitation is particularly important because it plays a major role in controlling the winter hydrological cycle and spring discharge. Nevertheless, observations of winter snowfall in high latitudes is challenging due to sharply decreasing numbers of precipitation gauges and gauge measurement biases. In addition, conventional satellite methods that work well in low-latitudes are unsuitable for the high latitude conditions. In this study, we present a new method of estimating winter snowfall in the arctic region with GRACE time varying gravity measurements. In northern high latitudes, it is very cold in winter, and thus solid precipitation accumulates with very limited melting and evapotranspiration. Therefore, observed gravity increments during winter mainly result from solid precipitation. We estimate amount of solid precipitation during winter (DJF) from four major arctic basins, Mackenzie, Lena, Yenisei and Ob. New estimates using satellite gravity are compared to global satellite and reanalysis precipitation products , which are GPCP, CMAP, NCEP/NCAR, ECMWF and JCDAS. GRACE-based estimates of snowfall are very close to those of CMAP, ECMWF and JCDAS. We extend the methodology to examine spatial distribution of solid precipitation in the pan-arctic land areas, which shows a good agreement with JCDAS. This new measurement of solid precipitation can provide an altogether new form of observations for hydrological cycle research studies, model and precipitation product evaluation and data assimilation efforts.

  10. On the new GPCC gridded reference data sets of observed (daily) monthly land-surface precipitation since (1988) 1901 published in 2014 including an all seasons open source test product

    NASA Astrophysics Data System (ADS)

    Ziese, Markus; Andreas, Becker; Peter, Finger; Anja, Meyer-Christoffer; Kirstin, Schamm; Udo, Schneider

    2014-05-01

    Since 1989 the Global Precipitation Climatology Centre (GPCC) collects world-wide observational in-situ data from rain gauges in order to provide gridded high quality and resolution land surface precipitation analyses as mandated by WMO's World Climate Research Program and the Global Climate Observing System (GCOS). In doing so a thorough quality control (QC) is performed on the original data prior to its entrance into the ever growing GPCC data archive being the world-wide largest with monthly totals for more than 90000 stations. Since 2012 also daily data is processed and the archive already holds daily data for more than 30000 stations with the aim to reach at least the same scope as for monthly data, ultimately. All archived data stems from various sources, e.g. national meteorological and hydrological services and regional or global data collections and is thus stored in source specific slots, allowing cross-checks on redundant records and subsequent QC at different sophistication levels depending on the timeliness demand on each product. All data products are referenced by digital object identifiers (DOIs all starting with "10.5676/DWD_GPCC/") and thus published in public domain (ftp://ftp-anon.dwd.de/pub/data/gpcc/html/download_gate.html) for minimum 10 years per product and version. In 2014 the monthly Full Data Reanalysis and the Climatology product releases of December 2011 are due for update. As the new Climatology product is also used as background climatology for all other data products, the Monitoring Product shall be re-processed for all years since 1986. Moreover the First Guess Products (daily and monthly) will benefit from the improved climatology. Finally, GPCC will release its first Full Data Daily Reanalysis product comprising the land-surface precipitation for every day since 1 January 1988. It will be extended backward in course of GPCC's participation in the ERA_CLIM2 re-analysis project. The double to triple size of the GPCC data archive

  11. Selective Precipitation of Proteins.

    PubMed

    Matulis, Daumantas

    2016-01-01

    Selective precipitation of proteins can be used as a bulk method to recover the majority of proteins from a crude lysate, as a selective method to fractionate a subset of proteins from a protein solution, or as a very specific method to recover a single protein of interest from a purification step. This unit describes a number of methods suitable for selective precipitation. In each of the protocols that are outlined, the physical or chemical basis of the precipitation process, the parameters that can be varied for optimization, and the basic steps for developing an optimized precipitation are described. PMID:26836410

  12. Global Precipitation Measurement

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.; Skofronick-Jackson, Gail; Kummerow, Christian D.; Shepherd, James Marshall

    2008-01-01

    This chapter begins with a brief history and background of microwave precipitation sensors, with a discussion of the sensitivity of both passive and active instruments, to trace the evolution of satellite-based rainfall techniques from an era of inference to an era of physical measurement. Next, the highly successful Tropical Rainfall Measuring Mission will be described, followed by the goals and plans for the Global Precipitation Measurement (GPM) Mission and the status of precipitation retrieval algorithm development. The chapter concludes with a summary of the need for space-based precipitation measurement, current technological capabilities, near-term algorithm advancements and anticipated new sciences and societal benefits in the GPM era.

  13. IMPROVED PROCESS OF PLUTONIUM CARRIER PRECIPITATION

    DOEpatents

    Faris, B.F.

    1959-06-30

    This patent relates to an improvement in the bismuth phosphate process for separating and recovering plutonium from neutron irradiated uranium, resulting in improved decontamination even without the use of scavenging precipitates in the by-product precipitation step and subsequently more complete recovery of the plutonium in the product precipitation step. This improvement is achieved by addition of fluomolybdic acid, or a water soluble fluomolybdate, such as the ammonium, sodium, or potassium salt thereof, to the aqueous nitric acid solution containing tetravalent plutonium ions and contaminating fission products, so as to establish a fluomolybdate ion concentration of about 0.05 M. The solution is then treated to form the bismuth phosphate plutonium carrying precipitate.

  14. Measurement of precipitation using lysimeters

    NASA Astrophysics Data System (ADS)

    Fank, Johann; Klammler, Gernot

    2013-04-01

    Austria's alpine foothill aquifers contain important drinking water resources, but are also used intensively for agricultural production. These groundwater bodies are generally recharged by infiltrating precipitation. A sustainable water resources management of these aquifers requires quantifying real evapotranspiration (ET), groundwater recharge (GR), precipitation (P) and soil water storage change (ΔS). While GR and ΔS can be directly measured by weighable lysimeters and P by separate precipitation gauges, ET is determined by solving the climatic water balance ET = P GR ± ΔS. According to WMO (2008) measurement of rainfall is strongly influenced by precipitation gauge errors. Most significant errors result from wind loss, wetting loss, evaporation loss, and due to in- and out-splashing of water. Measuring errors can be reduced by a larger area of the measuring gaugés surface and positioning the collecting vessel at ground level. Modern weighable lysimeters commonly have a surface of 1 m², are integrated into their typical surroundings of vegetation cover (to avoid oasis effects) and allow scaling the mass change of monolithic soil columns in high measuring accuracy (0.01 mm water equivalent) and high temporal resolution. Thus, also precipitation can be quantified by measuring the positive mass changes of the lysimeter. According to Meissner et al. (2007) also dew, fog and rime can be determined by means of highly precise weighable lysimeters. Furthermore, measuring precipitation using lysimeters avoid common measuring errors (WMO 2008) at point scale. Though, this method implicates external effects (background noise, influence of vegetation and wind) which affect the mass time series. While the background noise of the weighing is rather well known and can be filtered out of the mass time series, the influence of wind, which blows through the vegetation and affects measured lysimeter mass, cannot be corrected easily since there is no clear relation between

  15. Nutrient removal and energy production in a urine treatment process using magnesium ammonium phosphate precipitation and a microbial fuel cell technique.

    PubMed

    Zang, Guo-Long; Sheng, Guo-Ping; Li, Wen-Wei; Tong, Zhong-Hua; Zeng, Raymond J; Shi, Chen; Yu, Han-Qing

    2012-02-14

    Urine pretreatment has attracted increasing interest as it is able to relieve the nitrogen and phosphorus overloading problems in municipal wastewater treatment plants. In this study, an integrated process, which combines magnesium ammonium phosphate (MAP) precipitation with a microbial fuel cell (MFC), is proposed for the recovery of a slow-release fertilizer and electricity from urine. In such a two-step process, both nitrogen and phosphorus are recovered through the MAP process, and organic matters in the urine are converted into electricity in the MFCs. With this integrated process, when the phosphorus recovery is maximized without a dose of PO(4)(3-)-P in the MAP precipitation process, removal efficiencies for PO(4)(3)-P and NH(4)(+)-N of 94.6% and 28.6%, respectively, were achieved with a chemical oxygen demand (COD) of 64.9% accompanied by a power output of 2.6 W m(-3). Whereas removal efficiencies for PO(4)(3)-P and NH(4)(+)-N of 42.6% and 40%, respectively, and a COD of 62.4% and power density of 0.9 W m(-3) were obtained if simultaneous recovery of phosphorus and nitrogen was required through dosing with 620 mg L(-1) of PO(4)(3-)-P in the MAP process. This work provides a new sustainable approach for the efficient and cost-effective treatment of urine with the recovery of energy and resources. PMID:22234416

  16. Global Precipitation Measurement Poster

    NASA Technical Reports Server (NTRS)

    Azarbarzin, Art

    2010-01-01

    This poster presents an overview of the Global Precipitation Measurement (GPM) constellation of satellites which are designed to measure the Earth's precipitation. It includes the schedule of launches for the various satellites in the constellation, and the coverage of the constellation, It also reviews the mission capabilities, and the mission science objectives.

  17. PRECIPITATION OF PROTACTINIUM

    DOEpatents

    Moore, R.L.

    1958-07-15

    An lmprovement in the separation of protactinium from aqueous nitric acid solutions is described. 1t covers the use of lead dioxide and tin dioxide as carrier precipitates for the protactinium. In carrying out the process, divalent lead or divalent tin is addcd to the solution and oxidized, causing formation of a carrier precipitate of lead dioxide or stannic oxide, respectively.

  18. The Thorbex precipitation experiment

    NASA Astrophysics Data System (ADS)

    Nína Petersen, Guðrún; Ágústsson, Hálfdán; Ólafsson, Haraldur; Arason, Þórður

    2016-04-01

    During the autumn of 2014, precipitation was observed by a dense network of automatic raingauges covering a 243 m high and steep mountain, Þorbjörn, in the Reykjanes peninsula in SW-Iceland. The experiment is backed by continuous radar observations of winds and precipitation, radiosondes every 12 hours at the nearby Keflavik airport and a number of automatic weather stations. Some of the key results are: -The observations indicate that the average maximum rain over or close to the mountain maybe ~1.7 times the background rain. -Although the precipitation is only liquid, there seems to be great observation errors, likely due to strong winds. This calls for revision of the climatology of precipitation in Iceland and in other windy places. -The maximum wind loss and the spatial variability are of a similar magnitude. This complicates mapping of true precipitation.

  19. Precipitation and floodiness

    NASA Astrophysics Data System (ADS)

    Stephens, E.; Day, J. J.; Pappenberger, F.; Cloke, H.

    2015-12-01

    There are a number of factors that lead to nonlinearity between precipitation anomalies and flood hazard; this nonlinearity is a pertinent issue for applications that use a precipitation forecast as a proxy for imminent flood hazard. We assessed the degree of this nonlinearity for the first time using a recently developed global-scale hydrological model driven by the ERA-Interim/Land precipitation reanalysis (1980-2010). We introduced new indices to assess large-scale flood hazard, or floodiness, and quantified the link between monthly precipitation, river discharge, and floodiness anomalies at the global and regional scales. The results show that monthly floodiness is not well correlated with precipitation, therefore demonstrating the value of hydrometeorological systems for providing floodiness forecasts for decision-makers. A method is described for forecasting floodiness using the Global Flood Awareness System, building a climatology of regional floodiness from which to forecast floodiness anomalies out to 2 weeks.

  20. A New Method for Near Real Time Precipitation Estimates Using a Derived Statistical Relationship between Precipitable Water Vapor and Precipitation

    NASA Astrophysics Data System (ADS)

    Roman, J.

    2015-12-01

    The IPCC 5th Assessment found that the predicted warming of 1oC would increase the risk of extreme events such as heat waves, droughts, and floods. Weather extremes, like floods, have shown the vulnerability and susceptibility society has to these extreme weather events, through impacts such as disruption of food production, water supply, health, and damage of infrastructure. This paper examines a new way of near-real time forecasting of precipitation. A 10-year statistical climatological relationship was derived between precipitable water vapor (PWV) and precipitation by using the NASA Atmospheric Infrared Sounder daily gridded PWV product and the NASA Tropical Rainfall Measuring Mission daily gridded precipitation total. Forecasting precipitation estimates in real time is dire for flood monitoring and disaster management. Near real time PWV observations from AIRS on Aqua are available through the Goddard Earth Sciences Data and Information Service Center. In addition, PWV observations are available through direct broadcast from the NASA Suomi-NPP ATMS/CrIS instrument, the operational follow on to AIRS. The derived climatological relationship can be applied to create precipitation estimates in near real time by utilizing the direct broadcasting capabilities currently available in the CONUS region. The application of this relationship will be characterized through case-studies by using near real-time NASA AIRS Science Team v6 PWV products and ground-based SuomiNet GPS to estimate the current precipitation potential; the max amount of precipitation that can occur based on the moisture availability. Furthermore, the potential contribution of using the direct broadcasting of the NUCAPS ATMS/CrIS PWV products will be demonstrated. The analysis will highlight the advantages of applying this relationship in near-real time for flash flood monitoring and risk management. Relevance to the NWS River Forecast Centers will be discussed.

  1. Using total precipitable water anomaly as a forecast aid for heavy precipitation events

    NASA Astrophysics Data System (ADS)

    VandenBoogart, Lance M.

    Heavy precipitation events are of interest to weather forecasters, local government officials, and the Department of Defense. These events can cause flooding which endangers lives and property. Military concerns include decreased trafficability for military vehicles, which hinders both war- and peace-time missions. Even in data-rich areas such as the United States, it is difficult to determine when and where a heavy precipitation event will occur. The challenges are compounded in data-denied regions. The hypothesis that total precipitable water anomaly (TPWA) will be positive and increasing preceding heavy precipitation events is tested in order to establish an understanding of TPWA evolution. Results are then used to create a precipitation forecast aid. The operational, 16 km-gridded, 6-hourly TPWA product developed at the Cooperative Institute for Research in the Atmosphere (CIRA) compares a blended TPW product with a TPW climatology to give a percent of normal TPWA value. TPWA evolution is examined for 84 heavy precipitation events which occurred between August 2010 and November 2011. An algorithm which uses various TPWA thresholds derived from the 84 events is then developed and tested using dichotomous contingency table verification statistics to determine the extent to which satellite-based TPWA might be used to aid in forecasting precipitation over mesoscale domains. The hypothesis of positive and increasing TPWA preceding heavy precipitation events is supported by the analysis. Event-average TPWA rises for 36 hours and peaks at 154% of normal at the event time. The average precipitation event detected by the forecast algorithm is not of sufficient magnitude to be termed a "heavy" precipitation event; however, the algorithm adds skill to a climatological precipitation forecast. Probability of detection is low and false alarm ratios are large, thus qualifying the algorithm's current use as an aid rather than a deterministic forecast tool. The algorithm

  2. Precipitation patterns during channel flow

    NASA Astrophysics Data System (ADS)

    Jamtveit, B.; Hawkins, C.; Benning, L. G.; Meier, D.; Hammer, O.; Angheluta, L.

    2013-12-01

    Mineral precipitation during channelized fluid flow is widespread in a wide variety of geological systems. It is also a common and costly phenomenon in many industrial processes that involve fluid flow in pipelines. It is often referred to as scale formation and encountered in a large number of industries, including paper production, chemical manufacturing, cement operations, food processing, as well as non-renewable (i.e. oil and gas) and renewable (i.e. geothermal) energy production. We have studied the incipient stages of growth of amorphous silica on steel plates emplaced into the central areas of the ca. 1 meter in diameter sized pipelines used at the hydrothermal power plant at Hellisheidi, Iceland (with a capacity of ca 300 MW electricity and 100 MW hot water). Silica precipitation takes place over a period of ca. 2 months at approximately 120°C and a flow rate around 1 m/s. The growth produces asymmetric ca. 1mm high dendritic structures ';leaning' towards the incoming fluid flow. A novel phase-field model combined with the lattice Boltzmann method is introduced to study how the growth morphologies vary under different hydrodynamic conditions, including non-laminar systems with turbulent mixing. The model accurately predicts the observed morphologies and is directly relevant for understanding the more general problem of precipitation influenced by turbulent mixing during flow in channels with rough walls and even for porous flow. Reference: Hawkins, C., Angheluta, L., Hammer, Ø., and Jamtveit, B., Precipitation dendrites in channel flow. Europhysics Letters, 102, 54001

  3. Widespread Occurrence of Glyphosate and its Degradation Product (AMPA) in U.S. Soils, Surface Water, Groundwater, and Precipitation, 2001-2009

    NASA Astrophysics Data System (ADS)

    Brauman, K. A.; Flörke, M.; Mueller, N. D.; Foley, J. A.

    2011-12-01

    Water is integral to agricultural production, and agriculture is by far the largest human use of water, so food security and water sustainability are inexorably linked. When water goes to food production, however, the benefits and costs are not uniformly distributed across the globe. We quantify the magnitude and global range of the multidimensional tradeoffs among food production, water consumption, and water quality impairment. To evaluate the productivity of water consumption in agriculture, we quantified the magnitude and global range of crop water productivity, the amount of food produced per unit of water consumed, for 16 major food crops (Brauman et al., 2013). We now expand on this, contextualizing the impact of high or low water productivity with information about water availability. Using outputs from the WaterGAP3 model (Flörke et al., 2013, Verzano et al. 2012), we map the burden of agricultural water consumption on total water availability. To incorporate impacts of agriculture on water quality, we include areas of excess nutrient application (Mueller et al., 2012). The integrated information about yield, water consumption, water availability, and nutrient application shows that benefits and impacts to water quantity and quality are not evenly distributed. Analogous to previous investigations of 'yield gaps,' which identified areas where biophysical conditions are sufficient for achieving yields higher than those that are attained (Licker et al., 2010), we show that in many places, for the given impacts to water, food production could be increased.

  4. Global Precipitation Measurement (GPM) Mission Products and Services at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC)

    NASA Technical Reports Server (NTRS)

    Liu, Z.; Ostrenga, D.; Vollmer, B.; Kempler, S.; Deshong, B.; Greene, M.

    2015-01-01

    The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data within the NASA Earth Observation System Data Information System (EOSDIS). The GES DISC is also home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). Over the past 17 years, the GES DISC has served the scientific as well as other communities with TRMM data and user-friendly services. During the GPM era, the GES DISC will continue to provide user-friendly data services and customer support to users around the world. GPM products currently and to-be available: -Level-1 GPM Microwave Imager (GMI) and partner radiometer products, DPR products -Level-2 Goddard Profiling Algorithm (GPROF) GMI and partner products, DPR products -Level-3 daily and monthly products, DPR products -Integrated Multi-satellitE Retrievals for GPM (IMERG) products (early, late, and final) A dedicated Web portal (including user guides, etc.) has been developed for GPM data (http://disc.sci.gsfc.nasa.gov/gpm). Data services that are currently and to-be available include Google-like Mirador (http://mirador.gsfc.nasa.gov/) for data search and access; data access through various Web services (e.g., OPeNDAP, GDS, WMS, WCS); conversion into various formats (e.g., netCDF, HDF, KML (for Google Earth), ASCII); exploration, visualization, and statistical online analysis through Giovanni (http://giovanni.gsfc.nasa.gov); generation of value-added products; parameter and spatial subsetting; time aggregation; regridding; data version control and provenance; documentation; science support for proper data usage, FAQ, help desk; monitoring services (e.g. Current Conditions) for applications. The United User Interface (UUI) is the next step in the evolution of the GES DISC web site. It attempts to provide seamless access to data, information and services through a single interface without sending the user to different applications or URLs (e.g., search, access

  5. Chemisorption And Precipitation Reactions

    EPA Science Inventory

    The transport and bioavailability of chemical components within soils is, in part, controlled by partitioning between solids and solution. General terms used to describe these partitioning reactions include chemisorption and precipitation. Chemisorption is inclusive of the suit...

  6. Precipitation Estimates for Hydroelectricity

    NASA Technical Reports Server (NTRS)

    Tapiador, Francisco J.; Hou, Arthur Y.; de Castro, Manuel; Checa, Ramiro; Cuartero, Fernando; Barros, Ana P.

    2011-01-01

    Hydroelectric plants require precise and timely estimates of rain, snow and other hydrometeors for operations. However, it is far from being a trivial task to measure and predict precipitation. This paper presents the linkages between precipitation science and hydroelectricity, and in doing so it provides insight into current research directions that are relevant for this renewable energy. Methods described include radars, disdrometers, satellites and numerical models. Two recent advances that have the potential of being highly beneficial for hydropower operations are featured: the Global Precipitation Measuring (GPM) mission, which represents an important leap forward in precipitation observations from space, and high performance computing (HPC) and grid technology, that allows building ensembles of numerical weather and climate models.

  7. My NASA Data Precipitation

    NASA Video Gallery

    This lesson has two activities that help students develop a basic understanding of the relationship between cloud type and the form of precipitation and the relationship between the amount of water...

  8. IMERG Global Precipitation Rates

    NASA Video Gallery

    NASA's Global Precipitation Measurement mission has produced its first global map of rainfall and snowfall. The GPM Core Observatory launched one year ago on Feb. 27, 2014 as a collaboration betwee...

  9. Hydride precipitation in titanium

    SciTech Connect

    Numakura, H.; Kowia, M.

    1984-10-01

    The crystal structure and morphology of hydride (deuteride) precipitates are investigated on ..cap alpha..-titanium specimens containing 1-3 at.% H or D by transmission electron microscopy. The hydride is found to have a face-centered tetragonal structure (c/a = 1.09) with an ordered arrangement of hydrogen, being isomorphous to ..gamma..-zirconium hydride. Two types of precipitation mode are observed with the habit planes (0110) and near (0225).

  10. Global Precipitation Mission Visualization Tool

    NASA Technical Reports Server (NTRS)

    Schwaller, Mathew

    2011-01-01

    The Global Precipitation Mission (GPM) software provides graphic visualization tools that enable easy comparison of ground- and space-based radar observations. It was initially designed to compare ground radar reflectivity from operational, ground-based, S- and C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite's precipitation radar instrument. This design is also applicable to other groundbased and space-based radars, and allows both ground- and space-based radar data to be compared for validation purposes. The tool creates an operational system that routinely performs several steps. It ingests satellite radar data (precipitation radar data from TRMM) and groundbased meteorological radar data from a number of sources. Principally, the ground radar data comes from national networks of weather radars (see figure). The data ingested by the visualization tool must conform to the data formats used in GPM Validation Network Geometry-matched data product generation. The software also performs match-ups of the radar volume data for the ground- and space-based data, as well as statistical and graphical analysis (including two-dimensional graphical displays) on the match-up data. The visualization tool software is written in IDL, and can be operated either in the IDL development environment or as a stand-alone executable function.

  11. Distribution of soluble and precipitated iron and chromium products generated by anodic dissolution of 316L stainless steel and alloy C-22: final report

    SciTech Connect

    Estill, J; Farmer, J; Gordon, S; King, K; Logotetta, L; Silberman, D

    1999-08-11

    At near neutral pH and at applied potentials above the threshold potential for localized breakdown of the passive film, virtually all of the dissolved chromium appeared to be in the hexavalent oxidation state (Cr(VI)). In acidic environments, such as crevice solutions formed during the crevice corrosion of 316L and C-22 samples in 4 M NaCl, virtually all of the dissolved chromium appeared to be in the trivalent oxidation state (Cr(III)). These general observations appear to be consistent with the Pourbaix diagram for chromium (Pourbaix 1974), pp. 307-321. At high pH and high anodic polarization (pH {approximately} 8 and 800 mV vs. SHE), the predominate species is believed to be the soluble chromate anion (CrO{sub 4}{sup 2{minus}}). At the same pH, but lower polarization (pH {approximately} 8 and 0 mV vs. SHE), the predominate species are believed to be precipitates such as trivalent Cr(OH){sub 3} {center_dot} n(H{sub 2}O) and hexavalent Cr{sub 2}O{sub 3}. In acidified environments such as those found in crevices (pH < 3), soluble Cr{sup 3+} is expected to form over a wide range of potential extending from 400 mV vs. SHE to approximately 1200 mV vs. SHE. Again, this is consistent with the observations from the creviced samples. In earlier studies by the principal investigator, it has been found that low-level chromium contamination in ground water is usually in the hexavalent oxidation state (Farmer et al. 1996). In general, dissolved iron measured during the crevice experiments appears to be Fe(II) in acidic media and Fe(III) in near-neutral and alkaline solutions (table 3). In the case of cyclic polarization measurements, the dissolved iron measured at the end of some cyclic polarization measurements with C-22 appeared to be in the Fe(III) state. This is probably due to the high electrochemical potential at which these species were generated during the potential scan. Note that the reversal potential was approximately 1200 mV vs. Ag/AgCl during these scans. These

  12. Spatiotemporal changes of snow cover and its correlation with temperature and precipitation over the upstream area of Heihe River basin based on MODIS snow cover product from hydrological year 2001 to 2012

    NASA Astrophysics Data System (ADS)

    Bi, Y.; Xie, H.

    2013-12-01

    Snow cover is an important water source of major Asian rivers and greatly influences water availability in the downstream areas. In this study, snow cover dynamics of the upstream areas of Heihe River in the northwestern China during hydrological years 2001-2012 (September through August) are examined using the flexible multiday combined MODIS snow cover products. The time series of multiday, seasonal, and annual snow covered area (SCA), snow covered days (SCD), peaks of maximum SCA, and snow cover index (SCI) for each hydrological year (HY) are examined. Further analysis is also based on the four elevation zones based on the distribution of vegetation. Results show that for high elevation zones (3400 to 3800m, 3800 to 4200 m, and above 4200 m), there are two peaks of snow cover area (SCA) for each hydrological years (Sep to Oct and Mar to Apr). For low elevation zones ( below 2400 m and 2400 m to 3400 m), the large peaks appear in Nov to Dec for each year. Regression analysis is used to assess the role of elevation zone in determining the relative performance of temperature and precipitation as predictors of snow cover area. The results indicate that temperature is the main explanatory variable for snow cover at low elevation zone and precipitation is a better predictor of snow cover area at high elevation zone. Upstream area of Heihe River Basin

  13. The Global Precipitation Measurement (GPM) Project

    NASA Technical Reports Server (NTRS)

    Azarbarzin, Ardeshir; Carlisle, Candace

    2010-01-01

    The Global Precipitation Measurement (GP!v1) mission is an international cooperative effort to advance the understanding of the physics of the Earth's water and energy cycle. Accurate and timely knowledge of global precipitation is essential for understanding the weather/climate/ecological system, for improving our ability to manage freshwater resources, and for predicting high-impact natural hazard events including floods, droughts, extreme weather events, and landslides. The GPM Core Observatory will be a reference standard to uniformly calibrate data from a constellation of spacecraft with passive microwave sensors. GPM is being developed under a partnership between the United States (US) National Aeronautics and Space Administration (NASA) and the Japanese Aerospace and Exploration Agency (JAXA). NASA's Goddard Space Flight Center (GSFC), in Greenbelt, MD is developing the Core Observatory, two GPM Microwave Imager (GMI) instruments, Ground Validation System and Precipitation Processing System for the GPM mission. JAXA will provide a Dual-frequency Precipitation Radar (DPR) for installation on the Core satellite and launch services for the Core Observatory. The second GMI instrument will be flown on a partner-provided spacecraft. Other US agencies and international partners contribute to the GPM mission by providing precipitation measurements obtained from their own spacecraft and/or providing ground-based precipitation measurements to support ground validation activities. The Precipitation Processing System will provide standard data products for the mission.

  14. Multiresolution comparison of precipitation datasets for large-scale models

    NASA Astrophysics Data System (ADS)

    Chun, K. P.; Sapriza Azuri, G.; Davison, B.; DeBeer, C. M.; Wheater, H. S.

    2014-12-01

    Gridded precipitation datasets are crucial for driving large-scale models which are related to weather forecast and climate research. However, the quality of precipitation products is usually validated individually. Comparisons between gridded precipitation products along with ground observations provide another avenue for investigating how the precipitation uncertainty would affect the performance of large-scale models. In this study, using data from a set of precipitation gauges over British Columbia and Alberta, we evaluate several widely used North America gridded products including the Canadian Gridded Precipitation Anomalies (CANGRD), the National Center for Environmental Prediction (NCEP) reanalysis, the Water and Global Change (WATCH) project, the thin plate spline smoothing algorithms (ANUSPLIN) and Canadian Precipitation Analysis (CaPA). Based on verification criteria for various temporal and spatial scales, results provide an assessment of possible applications for various precipitation datasets. For long-term climate variation studies (~100 years), CANGRD, NCEP, WATCH and ANUSPLIN have different comparative advantages in terms of their resolution and accuracy. For synoptic and mesoscale precipitation patterns, CaPA provides appealing performance of spatial coherence. In addition to the products comparison, various downscaling methods are also surveyed to explore new verification and bias-reduction methods for improving gridded precipitation outputs for large-scale models.

  15. Precipitation of metal nitrides from chloride melts

    SciTech Connect

    Slater, S.A.; Miller, W.E.; Willit, J.L.

    1996-12-31

    Precipitation of actinides, lanthanides, and fission products as nitrides from molten chloride melts is being investigated for use as a final cleanup step in treating radioactive salt wastes generated by electrometallurgical processing of spent nuclear fuel. The radioactive components (eg, fission products) need to be removed to reduce the volume of high-level waste that requires disposal. To extract the fission products from the salt, a nitride precipitation process is being developed. The salt waste is first contacted with a molten metal; after equilibrium is reached, a nitride is added to the metal phase. The insoluble nitrides can be recovered and converted to a borosilicate glass after air oxidation. For a bench-scale experimental setup, a crucible was designed to contact the salt and metal phases. Solubility tests were performed with candidate nitrides and metal nitrides for which there are no solubility data. Experiments were performed to assess feasibility of precipitation of metal nitrides from chloride melts.

  16. Importance of snow to global precipitation

    NASA Astrophysics Data System (ADS)

    Field, P. R.; Heymsfield, A. J.

    2015-11-01

    Precipitation controls the availability of drinking water and viability of the land to support agriculture. Failure to accurately predict the location, magnitude, and frequency of precipitation impacts not only numerical weather forecasting but also climate modeling. It has been proposed that most rainfall events originate from ice that has melted to form rain. Here we use remote sensing from spaceborne cloud radar to quantify that idea. A new metric is constructed to quantify the fraction of rain events at the surface that are linked to snow melting at a higher altitude. CloudSat is used to show the global variation of the importance of snow in the precipitation process. In the tropics, subtropics, midlatitude and polar regions 0.3, 0.4, 0.8, and >0.9, respectively, of all precipitation events (>1 mm/d) are linked to the production of snow in clouds.

  17. Precipitating factors of insomnia.

    PubMed

    Bastien, Célyne H; Vallières, Annie; Morin, Charles M

    2004-01-01

    Insomnia is a prevalent health complaint whose onset is precipitated by a variety of factors. There is an important need to identify and describe these factors to improve our understanding of risk factors and the natural history of insomnia. This article is aimed at identifying and describing the types of precipitating factors related to the onset of insomnia. A total of 345 patients evaluated for insomnia at a sleep-disorders clinic completed a sleep survey and underwent a semistructured clinical interview. As part of the evaluation, the specific precipitating events related to the onset of insomnia were identified. Subsequently, these factors were categorized (work-school, family, physical or psychological health, or indeterminate), and their affective valence (negative, positive, or indeterminate) was coded. The most common precipitating factors of insomnia were related to family, health, and work-school events. Sixty-five percent of precipitating events had a negative valence. These events differed with the age of onset of insomnia but not with the gender of participants. These findings are useful to identify potential risk factors for insomnia and improve our understanding of the natural history of insomnia. PMID:15600224

  18. URANIUM PRECIPITATION PROCESS

    DOEpatents

    Thunaes, A.; Brown, E.A.; Smith, H.W.; Simard, R.

    1957-12-01

    A method for the recovery of uranium from sulfuric acid solutions is described. In the present process, sulfuric acid is added to the uranium bearing solution to bring the pH to between 1 and 1.8, preferably to about 1.4, and aluminum metal is then used as a reducing agent to convert hexavalent uranium to the tetravalent state. As the reaction proceeds, the pH rises amd a selective precipitation of uranium occurs resulting in a high grade precipitate. This process is an improvement over the process using metallic iron, in that metallic aluminum reacts less readily than metallic iron with sulfuric acid, thus avoiding consumption of the reducing agent and a raising of the pH without accomplishing the desired reduction of the hexavalent uranium in the solution. Another disadvantage to the use of iron is that positive ferric ions will precipitate with negative phosphate and arsenate ions at the pH range employed.

  19. FORMATION OF URANIUM PRECIPITATES

    DOEpatents

    Googin, J.M. Jr.

    1959-03-17

    A method is described for precipitation of uranium peroxide from uranium- containing solutions so as to obtain larger aggregates which facilitates washings decantations filtrations centrifugations and the like. The desired larger aggregate form is obtained by maintaining the pH of the solution in the approximate range of 1 to 3 and the temperature at about 25 deg C or below while carrytng out the precipitation. Then prior to removal of the precipitate a surface active sulfonated bicarboxyacids such as di-octyl sodium sulfo-succinates is incorporated in an anount of the order of 0.01 to 0.05 percent by weights and the slurry is allowed to ripen for about one-half hour at a temperatare below 10 deg C.

  20. Uncertainty Estimation of Global Precipitation Measurement through Objective Validation Strategy

    NASA Astrophysics Data System (ADS)

    KIM, H.; Utsumi, N.; Seto, S.; Oki, T.

    2014-12-01

    Since Tropical Rainfall Measuring Mission (TRMM) has been launched in 1997 as the first satellite mission dedicated to measuring precipitation, the spatiotemporal gaps of precipitation observation have been filled significantly. On February 27th, 2014, Dual-frequency Precipitation Radar (DPR) satellite has been launched as a core observatory of Global Precipitation Measurement (GPM), an international multi-satellite mission aiming to provide the global three hourly map of rainfall and snowfall. In addition to Ku-band, Ka-band radar is newly equipped, and their combination is expected to introduce higher precision than the precipitation measurement of TRMM/PR. In this study, the GPM level-2 orbit products are evaluated comparing to various precipitation observations which include TRMM/PR, in-situ data, and ground radar. In the preliminary validation over intercross orbits of DPR and TRMM, Ku-band measurements in both satellites shows very close spatial pattern and intensity, and the DPR is capable to capture broader range of precipitation intensity than of the TRMM. Furthermore, we suggest a validation strategy based on 'objective classification' of background atmospheric mechanisms. The Japanese 55-year Reanalysis (JRA-55) and auxiliary datasets (e.g., tropical cyclone best track) is used to objectively determine the types of precipitation. Uncertainty of abovementioned precipitation products is quantified as their relative differences and characterized for different precipitation mechanism. Also, it is discussed how the uncertainty affects the synthesis of TRMM and GPM for a long-term satellite precipitation observation records which is internally consistent.

  1. Precipitation-Regulated Feedback

    NASA Astrophysics Data System (ADS)

    Voit, Mark

    2016-07-01

    Star formation in the central galaxies of galaxy clusters appears to be fueled by precipitation of cold clouds out of hot circumgalactic gas via thermal instability. I will present both observational and theoretical support for the precipitation mode in large galaxies and discuss how it can be implemented in cosmological simulations of galaxy evolution. Galaxy cluster cores are unique laboratories for studying the astrophysics of thermal instability and may be teaching us valuable lessons about how feedback works in galaxies spanning the entire mass spectrum.

  2. Layer Precipitable Water (LPW) Briefing

    NASA Technical Reports Server (NTRS)

    Forsythe, John; Kidder, Stan; Fuell, Kevin; LeRoy, Anita

    2013-01-01

    Microwave Integrated Retrieval System (MIRS) provides soundings of specific humidity from a variety of instruments and is combined with AIRS infrared soundings to create a Layered Precipitable Water (LPW) composite product. The LPW provides vertical moisture information in the column instead of just upper levels via WV imagery, or a single column value via TPW products. LPW is created every 3 hours using the last 12 hours worth of data and has a delivery latency of 40 minutes. Weaknesses include discontinuities in the composite. Strengths include seeing through clouds, over land usage, and greater spatial coverage of vertical moisture profiles. Applications of LPW include analysis of horizontal and vertical moisture gradients, verification of NWP moisture, and analysis of atmospheric rivers and other moisture advection. Operational testbed is ongoing to determine viability of wider distribution.

  3. EFFECTS OF ACID PRECIPITATION

    EPA Science Inventory

    Recent reviews of available data indicate that precipitation in a large region of North America is highly acidic when its pH is compared with the expected pH value of 5.65 for pure rain water in equilibrium with CO2. A growing body of evidence suggests that acid rain is responsib...

  4. Global precipitation measurement (GPM)

    NASA Astrophysics Data System (ADS)

    Neeck, Steven P.; Flaming, Gilbert M.; Adams, W. James; Smith, Eric A.

    2001-12-01

    The National Aeronautics and Space Administration (NASA) is studying options for future space-based missions for the EOS Follow-on Era (post 2003), building upon the measurements made by Pre-EOS and EOS First Series Missions. One mission under consideration is the Global Precipitation Measurement (GPM), a cooperative venture of NASA, Japan, and other international partners. GPM will capitalize on the experience of the highly successful Tropical Rainfall Measurement Mission (TRMM). Its goal is to extend the measurement of rainfall to high latitudes with high temporal frequency, providing a global data set every three hours. A reference concept has been developed consisting of an improved TRMM-like primary satellite with precipitation radar and microwave radiometer to make detailed and accurate estimates of the precipitation structure and a constellation of small satellites flying compact microwave radiometers to provide the required temporal sampling of highly variable precipitation systems. Considering that DMSP spacecraft equipped with SSMIS microwave radiometers, successor NPOESS spacecraft equipped with CMIS microwave radiometers, and other relevant international systems are expected to be in operation during the timeframe of the reference concept, the total number of small satellites required to complete the constellation will be reduced. A nominal plan is to begin implementation in FY'03 with launches in 2007. NASA is presently engaged in advanced mission studies and advanced instrument technology development related to the mission.

  5. The Global Precipitation Mission

    NASA Technical Reports Server (NTRS)

    Braun, Scott; Kummerow, Christian

    2000-01-01

    The Global Precipitation Mission (GPM), expected to begin around 2006, is a follow-up to the Tropical Rainfall Measuring Mission (TRMM). Unlike TRMM, which primarily samples the tropics, GPM will sample both the tropics and mid-latitudes. The primary, or core, satellite will be a single, enhanced TRMM satellite that can quantify the 3-D spatial distributions of precipitation and its associated latent heat release. The core satellite will be complemented by a constellation of very small and inexpensive drones with passive microwave instruments that will sample the rainfall with sufficient frequency to be not only of climate interest, but also have local, short-term impacts by providing global rainfall coverage at approx. 3 h intervals. The data is expected to have substantial impact upon quantitative precipitation estimation/forecasting and data assimilation into global and mesoscale numerical models. Based upon previous studies of rainfall data assimilation, GPM is expected to lead to significant improvements in forecasts of extratropical and tropical cyclones. For example, GPM rainfall data can provide improved initialization of frontal systems over the Pacific and Atlantic Oceans. The purpose of this talk is to provide information about GPM to the USWRP (U.S. Weather Research Program) community and to discuss impacts on quantitative precipitation estimation/forecasting and data assimilation.

  6. Total Precipitable Water

    SciTech Connect

    2012-01-01

    The simulation was performed on 64K cores of Intrepid, running at 0.25 simulated-years-per-day and taking 25 million core-hours. This is the first simulation using both the CAM5 physics and the highly scalable spectral element dynamical core. The animation of Total Precipitable Water clearly shows hurricanes developing in the Atlantic and Pacific.

  7. Precipitation from Space: Advancing Earth System Science

    NASA Technical Reports Server (NTRS)

    Kucera, Paul A.; Ebert, Elizabeth E.; Turk, F. Joseph; Levizzani, Vicenzo; Kirschbaum, Dalia; Tapiador, Francisco J.; Loew, Alexander; Borsche, M.

    2012-01-01

    Of the three primary sources of spatially contiguous precipitation observations (surface networks, ground-based radar, and satellite-based radar/radiometers), only the last is a viable source over ocean and much of the Earth's land. As recently as 15 years ago, users needing quantitative detail of precipitation on anything under a monthly time scale relied upon products derived from geostationary satellite thermal infrared (IR) indices. The Special Sensor Microwave Imager (SSMI) passive microwave (PMW) imagers originated in 1987 and continue today with the SSMI sounder (SSMIS) sensor. The fortunate longevity of the joint National Aeronautics and Space Administration (NASA) and Japan Aerospace Exploration Agency (JAXA) Tropical Rainfall Measuring Mission (TRMM) is providing the environmental science community a nearly unbroken data record (as of April 2012, over 14 years) of tropical and sub-tropical precipitation processes. TRMM was originally conceived in the mid-1980s as a climate mission with relatively modest goals, including monthly averaged precipitation. TRMM data were quickly exploited for model data assimilation and, beginning in 1999 with the availability of near real time data, for tropical cyclone warnings. To overcome the intermittently spaced revisit from these and other low Earth-orbiting satellites, many methods to merge PMW-based precipitation data and geostationary satellite observations have been developed, such as the TRMM Multisatellite Precipitation Product and the Climate Prediction Center (CPC) morphing method (CMORPH. The purpose of this article is not to provide a survey or assessment of these and other satellite-based precipitation datasets, which are well summarized in several recent articles. Rather, the intent is to demonstrate how the availability and continuity of satellite-based precipitation data records is transforming the ways that scientific and societal issues related to precipitation are addressed, in ways that would not be

  8. The TRMM Multi-satellite Precipitation Analysis (TMPA): Quasi-Global Precipitation Estimates at Fine Scales

    NASA Technical Reports Server (NTRS)

    Huffman, George J.; Adler, Robert F.; Bolvin, David T.; Gu, Guojun; Nelkin, Eric J.; Bowman, Kenneth P.; Stocker, Erich; Wolff, David B.

    2006-01-01

    The TRMM Multi-satellite Precipitation Analysis (TMPA) provides a calibration-based sequential scheme for combining multiple precipitation estimates from satellites, as well as gauge analyses where feasible, at fine scales (0.25 degrees x 0.25 degrees and 3-hourly). It is available both after and in real time, based on calibration by the TRMM Combined Instrument and TRMM Microwave Imager precipitation products, respectively. Only the after-real-time product incorporates gauge data at the present. The data set covers the latitude band 50 degrees N-S for the period 1998 to the delayed present. Early validation results are as follows: The TMPA provides reasonable performance at monthly scales, although it is shown to have precipitation rate dependent low bias due to lack of sensitivity to low precipitation rates in one of the input products (based on AMSU-B). At finer scales the TMPA is successful at approximately reproducing the surface-observation-based histogram of precipitation, as well as reasonably detecting large daily events. The TMPA, however, has lower skill in correctly specifying moderate and light event amounts on short time intervals, in common with other fine-scale estimators. Examples are provided of a flood event and diurnal cycle determination.

  9. Illinois Precipitation Research: A Focus on Cloud and Precipitation Modification.

    NASA Astrophysics Data System (ADS)

    Changnon, Stanley A.; Czys, Robert R.; Scott, Robert W.; Westcott, Nancy E.

    1991-05-01

    At the heart of the 40-year atmospheric research endeavors of the Illinois State Water Survey have been studies to understand precipitation processes in order to learn how precipitation is modified purposefully and accidentally, and to measure the physical and socio-economic consequences of cloud and precipitation modification. Major field and laboratory activities of past years or briefly treated as a basis for describing the key findings of the past ten years. Recent studies of inadvertent and purposeful cloud and rain modification and their effects are emphasized, including a 1989 field project conducted in Illinois and key findings from an on-going exploratory experiment addressing cloud and rain modification. Results are encouraging for the use of dynamic seeding on summer cumuliform clouds of the Midwest.Typical in-cloud results at 10°C reveal multiple updrafts that tend to be filled with large amounts of supercooled drizzle and raindrops. Natural ice production is vigorous, and initial concentrations are larger than expected from ice nuclei. However, natural ice production is not so vigorous as to preclude opportunities for seeding. Radar-based studies of such clouds reveal that their echo cores usually can be identified prior to desired seeding times, which is significant for the evaluation of their behavior. Cell characteristics show considerable variance under different types of meteorological conditions. Analysis of cell mergers reveals that under conditions of weak vertical shear, mid-level intercell flow at 4 km occurs as the reflectivity bridge between cells rapidly intensifies. The degree of intensification of single-echo cores after they merge is strongly related to the age and vigor of the cores before they join. Hence, cloud growth may be enhanced if seeding can encourage echo cores to merge at critical times. Forecasting research has developed a technique for objectively distinguishing between operational seeding and nonoperational days and for

  10. Precipitation Indices Low Countries

    NASA Astrophysics Data System (ADS)

    van Engelen, A. F. V.; Ynsen, F.; Buisman, J.; van der Schrier, G.

    2009-09-01

    Since 1995, KNMI published a series of books(1), presenting an annual reconstruction of weather and climate in the Low Countries, covering the period AD 763-present, or roughly, the last millennium. The reconstructions are based on the interpretation of documentary sources predominantly and comparison with other proxies and instrumental observations. The series also comprises a number of classifications. Amongst them annual classifications for winter and summer temperature and for winter and summer dryness-wetness. The classification of temperature have been reworked into peer reviewed (2) series (AD 1000-present) of seasonal temperatures and temperature indices, the so called LCT (Low Countries Temperature) series, now incorporated in the Millennium databases. Recently we started a study to convert the dryness-wetness classifications into a series of precipitation; the so called LCP (Low Countries Precipitation) series. A brief outline is given here of the applied methodology and preliminary results. The WMO definition for meteorological drought has been followed being that a period is called wet respectively dry when the amount of precipitation is considerable more respectively less than usual (normal). To gain a more quantitative insight for four locations, geographically spread over the Low Countries area (De Bilt, Vlissingen, Maastricht and Uccle), we analysed the statistics of daily precipitation series, covering the period 1900-present. This brought us to the following definition, valid for the Low Countries: A period is considered as (very) dry respectively (very) wet if over a continuous period of at least 60 days (~two months) cq 90 days (~three months) on at least two out of the four locations 50% less resp. 50% more than the normal amount for the location (based on the 1961-1990 normal period) has been measured. This results into the following classification into five drought classes hat could be applied to non instrumental observations: Very wet period

  11. Using Satellite Precipitation to Improve Flood Modeling Applications of Global Reanalysis Precipitation Datasets

    NASA Astrophysics Data System (ADS)

    Seyyedi, Hojjat; Anagnostou, Emmanouil; Beighley, Edward; McCollum, Jeffrey

    2015-04-01

    Deriving flood vulnerability maps at basin scale typically requires simulating a long record of annual maximum discharges. To improve this approach, long precipitation records from global reanalysis systems must be downscaled to a spatio-temporal resolution applicable for flood modeling. This study evaluates a combined spatial downscaling and error correction technique based on high-resolution satellite precipitation products applied on NASA's Global Land Data Assimilation System (GLDAS) reanalysis precipitation dataset. The TRMM 3B42 25-km and 3-hourly blended satellite precipitation product is used for driving the GLDAS reanalysis downscaling. The study focuses on 437 flood-inducing storm events that occurred over a period of ten years (2002-2011) in the Susquehanna River basin located in the northeast United States. A validation strategy was devised for assessing error metrics in rainfall and simulated runoff as function of basin area, storm severity and season. The WSR-88D gauge-adjusted radar-rainfall (stage IV) product was used as the reference rainfall dataset, while runoff simulations forced with the stage IV precipitation dataset were considered as the runoff reference. Results show that the generated rainfall ensembles from the downscaled reanalysis products encapsulate the reference rainfall. Frequency analysis of rainfall and runoff and mean relative error and root mean square error statistics exhibited improvements in the precipitation and runoff simulation error statistics of the 3B42-driven downscaled GLDAS reanalysis dataset compared to the original reanalysis precipitation product. Results vary by season and less by basin scale. The proposed downscaling scheme is modular in design and can be applied on different satellite and reanalysis dataset over different regions.

  12. Homogeneous Precipitation of Nickel Hydroxide Powders

    SciTech Connect

    Bora Mavis

    2003-12-12

    Precipitation and characterization of nickel hydroxide powders were investigated. A comprehensive precipitation model incorporating the metal ion hydrolysis, complexation and precipitation reactions was developed for the production of the powders with urea precipitation method. Model predictions on Ni{sup 2+} precipitation rate were confirmed with precipitation experiments carried out at 90 C. Experimental data and model predictions were in remarkable agreement. Uncertainty in the solubility product data of nickel hydroxides was found to be the large contributor to the error. There were demonstrable compositional variations across the particle cross-sections and the growth mechanism was determined to be the aggregation of primary crystallites. This implied that there is a change in the intercalate chemistry of the primary crystallites with digestion time. Predicted changes in the concentrations of simple and complex ions in the solution support the proposed mechanism. The comprehensive set of hydrolysis reactions used in the model described above allows the investigation of other systems provided that accurate reaction constants are available. the fact that transition metal ions like Ni{sup 2+} form strong complexes with ammonia presents a challenge in the full recovery of the Ni{sup 2+}. On the other hand, presence of Al{sup 3+} facilitates the complete precipitation of Ni{sup 2+} in about 3 hours of digestion. A challenge in their predictive modeling studies had been the fact that simultaneous incorporation of more than one metal ion necessitates a different approach than just using the equilibrium constants of hydrolysis, complexation and precipitation reactions. Another limitation of using equilibrium constants is that the nucleation stage of digestion, which is controlled mainly by kinetics, is not fully justified. A new program released by IBM Almaden Research Center (Chemical Kinetics Simulator{trademark}, Version 1.01) lets the user change the order of

  13. Precipitation hardening austenitic superalloys

    DOEpatents

    Korenko, Michael K.

    1985-01-01

    Precipitation hardening, austenitic type superalloys are described. These alloys contain 0.5 to 1.5 weight percent silicon in combination with about 0.05 to 0.5 weight percent of a post irradiation ductility enhancing agent selected from the group of hafnium, yttrium, lanthanum and scandium, alone or in combination with each other. In addition, when hafnium or yttrium are selected, reductions in irradiation induced swelling have been noted.

  14. Precipitation Storage Efficiency During Fallow in Wheat-Fallow Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat-fallow production systems arose in order to stabilize widely ranging wheat yields that resulted from highly variable precipitation in the Great Plains. Historically, precipitation storage efficiency (PSE) over the fallow period increased over time as inversion tillage systems used for weed con...

  15. Effect of Previous Fall Precipitation on Mixed-Grass Prairie

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precipitation accounts for much of the year-to-year variation in forage production. Prediction of forage growth early in the season from readily available information about precipitation would help with choosing stocking rates when drought reduces forage growth. Previously, models were identified t...

  16. Precipitation Indices Low Countries

    NASA Astrophysics Data System (ADS)

    van Engelen, A. F. V.; Ynsen, F.; Buisman, J.; van der Schrier, G.

    2009-09-01

    Since 1995, KNMI published a series of books(1), presenting an annual reconstruction of weather and climate in the Low Countries, covering the period AD 763-present, or roughly, the last millennium. The reconstructions are based on the interpretation of documentary sources predominantly and comparison with other proxies and instrumental observations. The series also comprises a number of classifications. Amongst them annual classifications for winter and summer temperature and for winter and summer dryness-wetness. The classification of temperature have been reworked into peer reviewed (2) series (AD 1000-present) of seasonal temperatures and temperature indices, the so called LCT (Low Countries Temperature) series, now incorporated in the Millennium databases. Recently we started a study to convert the dryness-wetness classifications into a series of precipitation; the so called LCP (Low Countries Precipitation) series. A brief outline is given here of the applied methodology and preliminary results. The WMO definition for meteorological drought has been followed being that a period is called wet respectively dry when the amount of precipitation is considerable more respectively less than usual (normal). To gain a more quantitative insight for four locations, geographically spread over the Low Countries area (De Bilt, Vlissingen, Maastricht and Uccle), we analysed the statistics of daily precipitation series, covering the period 1900-present. This brought us to the following definition, valid for the Low Countries: A period is considered as (very) dry respectively (very) wet if over a continuous period of at least 60 days (~two months) cq 90 days (~three months) on at least two out of the four locations 50% less resp. 50% more than the normal amount for the location (based on the 1961-1990 normal period) has been measured. This results into the following classification into five drought classes hat could be applied to non instrumental observations: Very wet period

  17. A unified approach to asphaltene precipitation: Laboratory measurement and modeling

    SciTech Connect

    MacMillan, D.J.; Tackett, J.E. Jr.; Jessee, M.A.; Monger-McClure, T.G.

    1995-11-01

    A unified approach to evaluating asphaltene precipitation based on laboratory measurement and modeling is presented. This approach used an organic deposition cell for measuring asphaltene drop out onset conditions. Asphaltene precipitation was detected by changes in optical fluorescence, electrical conductance, and visual observation. A series of experiments measured the effects of changing pressure, temperature and composition on asphaltene precipitation. A fully-compositional V-L-S mathematical model completed the analysis by matching the experimental results. The model was then used to forecast asphaltene precipitation under a variety of production scenarios including response to gas-lift operations, and to evaluate the possible location of a tar-mat.

  18. Rain use efficiency across a precipitation gradient on the Tibetan Plateau

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rain use efficiency (RUE), commonly described as the ratio of aboveground net primary production (ANPP) to mean annual precipitation (MAP), is a critical indicator for predicting potential responses of grassland ecosystems to changing precipitation regimes. However, current understanding on patterns...

  19. GIS based Spatial Precipitation Estimation using Next Generation Radar and Raingauge Data

    SciTech Connect

    Zhang, Xuesong; Srinivasan, Ragahvan

    2010-01-01

    Precipitation is one important input variable for land surface hydrologic and ecological models. Next Generation Radar (NEXRAD) can provide precipitation products that cover most of the conterminous United States at high resolution (approximately 4km×4km).

  20. CALCULATION: PRECIPITATION CHARACTERISITICS FOR STORM WATER MANAGEMENT

    SciTech Connect

    D. Ambos

    2000-08-14

    This Calculation is intended to satisfy engineering requirements for maximum 60-minute precipitation amounts for 50 and 100-year return periods at and near Yucca Mountain. This data requirement is documented in the ''Interface Control Document for Support Operations to Surface Facilities Operations Functional and Organizational Interfaces'' (CRWMS M&O 1998a). These developed data will supplement the information on 0.1 hour to 6-hour (in 0.1-hour increments) probable maximum precipitation (PMP) presented in the report, ''Precipitation Design Criteria for Storm Water Management'' (CRWMS M&O 1998b). The Reference Information Base (RIB) item, Precipitation ''Characteristics for Storm Water Management'' (M09902RIB00045 .OOO), was developed based on CRWMS M&O (1998b) and will be supplemented (via revision) with the information developed in this Calculation. The ''Development Plan for the Calculation: Precipitation Characteristics for Storm Water Management'' (CRWMS M&O 2000) was prepared in accordance with AP-2.l3Q, ''Technical Product Development Planning''. This calculation was developed in accordance with AP-3.12Q, Rev. O/ICN 2.

  1. DISSOLUTION OF LANTHANUM FLUORIDE PRECIPITATES

    DOEpatents

    Fries, B.A.

    1959-11-10

    A plutonium separatory ore concentration procedure involving the use of a fluoride type of carrier is presented. An improvement is given in the derivation step in the process for plutonium recovery by carrier precipitation of plutonium values from solution with a lanthanum fluoride carrier precipitate and subsequent derivation from the resulting plutonium bearing carrier precipitate of an aqueous acidic plutonium-containing solution. The carrier precipitate is contacted with a concentrated aqueous solution of potassium carbonate to effect dissolution therein of at least a part of the precipitate, including the plutonium values. Any remaining precipitate is separated from the resulting solution and dissolves in an aqueous solution containing at least 20% by weight of potassium carbonate. The reacting solutions are combined, and an alkali metal hydroxide added to a concentration of at least 2N to precipitate lanthanum hydroxide concomitantly carrying plutonium values.

  2. Successes with the Global Precipitation Measurement (GPM) Mission

    NASA Technical Reports Server (NTRS)

    Skofronick-Jackson, Gail; Huffman, George; Stocker, Erich; Petersen, Walter

    2016-01-01

    Water is essential to our planet Earth. Knowing when, where and how precipitation falls is crucial for understanding the linkages between the Earth's water and energy cycles and is extraordinarily important for sustaining life on our planet during climate change. The Global Precipitation Measurement (GPM) Core Observatory spacecraft launched February 27, 2014, is the anchor to the GPM international satellite mission to unify and advance precipitation measurements from a constellation of research and operational sensors to provide "next-generation" precipitation products. GPM is currently a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA). Status and successes in terms of spacecraft, instruments, retrieval products, validation, and impacts for science and society will be presented. Precipitation, microwave, satellite

  3. Impacts of Light Precipitation Detection with Dual Frequency Radar on Global Precipitation Measurement Core Observatory (GPM/DPR)

    NASA Astrophysics Data System (ADS)

    Takayabu, Y. N.; Hamada, A.; Oki, R.; Kachi, M.; Kubota, T.; Iguchi, T.; Shige, S.; Nakamura, K.

    2014-12-01

    The Dual-frequency Precipitation Radar (DPR) on board the GPM Core Observatory consists of Ku-band (13.6 GHz) and Ka-band (35.5 GHz) radars, with an improved minimum detection sensitivity of precipitation compared to the Tropical Rainfall Measuring Mission Precipitation Radar (TRMM PR). We have studied impacts of improved detection sensitivity with the GPM DPR compared with the TRMM PR. One example of light precipitation is, a scattered rainfall around a trough over the subtropical South Pacific Ocean, which consists of weak but erect precipitation reaching over the melting level of ~2.5 km and trailing precipitation above, which reaches as high as 5km. Another example is a light anvil precipitation spreading from convective cores of a storm in the upper troposphere, overcasting shallow convective precipitation below. The ability of globally detecting such light precipitation will improve our knowledge of precipitation processes. Utilizing an early version of the DPR product, a quick evaluation on statistical impacts of increasing the detection sensitivity from 17dBZ to 12dBZ has been performed. Here, 17dBZ is the value which is mostly accepted as the performed detection sensitivity of the TRMM PR, and 12dBZ is the guaranteed sensitivity for GPM Ka-band radar. For the near surface precipitation, impacts are significant in terms of numbers, but limited to several regions in terms of the rainfall volume. Volume impacts are much larger at the upper troposphere, which is indicated by the detection of the anvil precipitation, for example. The upper level improvements are mostly found where the deep precipitation systems exist. Quantitative discussions utilizing the latest version of the DPR data, which is scheduled to be released to the public in September, will be presented at the session.

  4. Investigation of Neptunium Precipitator Cleanout Options

    SciTech Connect

    Hill, B.C.

    2003-09-08

    Oxalate precipitation followed by filtration is used to prepare plutonium oxalate. Historically, plutonium oxalate has tended to accumulate in the precipitation tanks. These solids are periodically removed by flushing with concentrated (64 percent) nitric acid. The same precipitation tanks will now be used in the processing of neptunium. Literature values indicate that neptunium oxalate may not be as soluble as plutonium oxalate in nitric acid. Although a wide variety of options is available to improve neptunium oxalate solubility for precipitator flushing, most of these options are not practical for use. Many of these options require the use of incompatible or difficult to handle chemicals. Other options would require expensive equipment modifications or are likely to lead to product contamination. Based on review of literature and experimental results, the two best options for flushing the precipitator are (1) 64 percent nitric acid and (2) addition of sodium permanganate follow ed by sodium nitrite. Nitric acid is the easiest option to implement. It is already used in the facility and will not lead to product contamination. Experimental results indicate that neptunium oxalate can be dissolved in concentrated nitric acid (64 percent) at 60 degree C to a concentration of 2.6 to 5.6 grams of Np/liter after at least three hours of heating. A lower concentration (1.1 grams of Np/liter) was measured at 60 degree C after less than two hours of heating. These concentrations are acceptable for flushing if precipitator holdup is low (approximately 100-250 grams), but a second method is required for effective flushing if precipitator holdup is high (approximately 2 kilograms). The most effective method for obtaining higher neptunium concentrations is the use of sodium permanganate followed by the addition of sodium nitrite. There is concern that residual manganese from these flushes could impact product purity. Gas generation during permanganate addition is also a concern

  5. The Version 2 Global Precipitation Climatology Project (GPCP) Monthly Precipitation Analysis (1979-Present)

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Huffman, George J.; Chang, Alfred; Ferraro, Ralph; Xie, Ping-Ping; Janowiak, John; Rudolf, Bruno; Schneider, Udo; Curtis, Scott; Bolvin, David

    2003-01-01

    The Global Precipitation Climatology Project (GPCP) Version 2 Monthly Precipitation Analysis is described. This globally complete, monthly analysis of surface precipitation at 2.5 degrees x 2.5 degrees latitude-longitude resolution is available from January 1979 to the present. It is a merged analysis that incorporates precipitation estimates from low-orbit-satellite microwave data, geosynchronous-orbit-satellite infrared data, and rain gauge observations. The merging approach utilizes the higher accuracy of the low-orbit microwave observations to calibrate, or adjust, the more frequent geosynchronous infrared observations. The data set is extended back into the premicrowave era (before 1987) by using infrared-only observations calibrated to the microwave-based analysis of the later years. The combined satellite-based product is adjusted by the raingauge analysis. This monthly analysis is the foundation for the GPCP suite of products including those at finer temporal resolution, satellite estimate, and error estimates for each field. The 23-year GPCP climatology is characterized, along with time and space variations of precipitation.

  6. PROCESS OF TREATING OR FORMING AN INSOLUBLE PLUTONIUM PRECIPITATE IN THE PRESENCE OF AN ORGANIC ACTIVE AGENT

    DOEpatents

    Balthis, J.H.

    1961-07-18

    Carrier precipitation processes for the separation of plutonium from fission products are described. In a process in which an insoluble precipitate is formed in a solution containing plutonium and fission products under conditions whereby plutonium is carried by the precipitate, and the precipitate is then separated from the remaining solution, an organic surface active agent is added to the mixture of precipitate and solution prior to separation of the precipitate from the supernatant solution, thereby improving the degree of separation of the precipitate from the solution.

  7. Evaluation of Uncertainty in Precipitation Datasets for New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Besha, A. A.; Steele, C. M.; Fernald, A.

    2014-12-01

    Climate change, population growth and other factors are endangering water availability and sustainability in semiarid/arid areas particularly in the southwestern United States. Wide coverage of spatial and temporal measurements of precipitation are key for regional water budget analysis and hydrological operations which themselves are valuable tool for water resource planning and management. Rain gauge measurements are usually reliable and accurate at a point. They measure rainfall continuously, but spatial sampling is limited. Ground based radar and satellite remotely sensed precipitation have wide spatial and temporal coverage. However, these measurements are indirect and subject to errors because of equipment, meteorological variability, the heterogeneity of the land surface itself and lack of regular recording. This study seeks to understand precipitation uncertainty and in doing so, lessen uncertainty propagation into hydrological applications and operations. We reviewed, compared and evaluated the TRMM (Tropical Rainfall Measuring Mission) precipitation products, NOAA's (National Oceanic and Atmospheric Administration) Global Precipitation Climatology Centre (GPCC) monthly precipitation dataset, PRISM (Parameter elevation Regression on Independent Slopes Model) data and data from individual climate stations including Cooperative Observer Program (COOP), Remote Automated Weather Stations (RAWS), Soil Climate Analysis Network (SCAN) and Snowpack Telemetry (SNOTEL) stations. Though not yet finalized, this study finds that the uncertainty within precipitation estimates datasets is influenced by regional topography, season, climate and precipitation rate. Ongoing work aims to further evaluate precipitation datasets based on the relative influence of these phenomena so that we can identify the optimum datasets for input to statewide water budget analysis.

  8. Mixing Zones and Mineral Precipitation Dynamics in Porous Media

    NASA Astrophysics Data System (ADS)

    Gebrehiwet, T.; Henrikson, J.; Guo, L.; Fox, D. T.; Huang, H.; Fujita, Y.; Tu, L.

    2011-12-01

    Precipitation of mineral phases in subsurface environments involves coupling between reactant transport and changes in media properties that control transport. Chemical gradients within mixing zones will determine the rates and products of reactions, which in turn can modify the permeability and flow paths within the porous media. This reaction-transport coupling is being studied using double diffusion experiments and reactive transport modeling, with calcium carbonate and calcium phosphate as the model mineral systems. In particular we are investigating: (1) the interplay between permeability modifications and reactions that can change local chemical conditions, hydrodynamic conditions, and therefore the rate of precipitation, (2) narrowing ("focusing") of the precipitation zone, and (3) migration of the precipitation zone associated with asymmetry across the mixing zone with respect to precipitation rates and/or local chemical conditions. Experiments are being conducted in hydrogel (polyacrylamide) and granular (glass beads and fine-grained sand) media. Gels were used to investigate the role of diffusion alone on the structure of precipitation zones. We observed differences between carbonate and phosphate systems with respect to the induction period for precipitation, and the position and migration of the precipitation zone. One interesting observation was that multiple precipitation bands are produced in the calcium phosphate system, while no clear banding has been observed in the calcium carbonate system. Initial reactive transport simulations that couple precipitation kinetics with reactant transport and mixing appear consistent with the experimental observations. Precipitation band width and position were found to change with time, and precipitation appeared to slow subsequent reactions at the mixing interfaces. The induction time, spacing between the precipitation bands and band width in the calcium phosphate system were influenced by pH, saturation state

  9. Gauge Adjusted Global Satellite Mapping of Precipitation (GSMAP_GAUGE)

    NASA Astrophysics Data System (ADS)

    Mega, T.; Ushio, T.; Yoshida, S.; Kawasaki, Z.; Kubota, T.; Kachi, M.; Aonashi, K.; Shige, S.

    2013-12-01

    Precipitation is one of the most important parameters on the earth system, and the global distribution of precipitation and its change are essential data for modeling the water cycle, maintaining the ecosystem environment, agricultural production, improvements of the weather forecast precision, flood warning and so on. The GPM (Global Precipitation Measurement) project is led mainly by the United States and Japan, and is now being actively promoted in Europe, France, India, and China with international cooperation. In this project, the microwave radiometers observing microwave emission from rain will be placed on many low-orbit satellites, to reduce the interval to about 3 hours in observation time for each location on the earth. However, the problem of sampling error arises if the global precipitation estimates are less than three hours. Therefore, it is necessary to utilize a gap-filling technique to generate precipitation maps with high temporal resolution, which is quite important for operational uses such as flash flood warning systems. Global Satellite Mapping of Precipitation (GSMaP) project was established by the Japan Science and Technology Agency (JST) in 2002 to produce global precipitation products with high resolution and high precision from not only microwave radiometers but also geostationary infrared radiometers. Currently, the GSMaP_MVK product has been successfully producing fairly good pictures in near real time, and the products shows a comparable score compared with other high-resolution precipitation systems (Ushio et al. 2009 and Kubota et al. 2009). However some evaluations particularly of the operational applications show the tendency of underestimation compared to some ground based observations for the cases showing extremely high precipitation rates. This is partly because the spatial and temporal samplings of the satellite estimates are different from that of the ground based estimates. The microwave imager observes signals from

  10. A global satellite-assisted precipitation climatology

    NASA Astrophysics Data System (ADS)

    Funk, C.; Verdin, A.; Michaelsen, J.; Peterson, P.; Pedreros, D.; Husak, G.

    2015-10-01

    Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti) are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high-resolution (0.05°) global precipitation climatologies that perform reasonably well in data-sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology, the Climate

  11. A global satellite assisted precipitation climatology

    USGS Publications Warehouse

    Funk, Christopher C.; Verdin, Andrew P.; Michaelsen, Joel C.; Pedreros, Diego; Husak, Gregory J.; Peterson, P.

    2015-01-01

    Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti) are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high resolution (0.05°) global precipitation climatologies that perform reasonably well in data sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology, the Climate

  12. Precipitation Estimation from Remotely Sensed Data Using Deep Neural Network

    NASA Astrophysics Data System (ADS)

    Tao, Y.; Gao, X.; Hsu, K. L.; Sorooshian, S.; Ihler, A.

    2015-12-01

    This research develops a precipitation estimation system from remote sensed data using state-of-the-art machine learning algorithms. Compared to ground-based precipitation measurements, satellite-based precipitation estimation products have advantages of temporal resolution and spatial coverage. Also, the massive amount of satellite data contains various measures related to precipitation formation and development. On the other hand, deep learning algorithms were newly developed in the area of machine learning, which was a breakthrough to deal with large and complex dataset, especially to image data. Here, we attempt to engage deep learning techniques to provide hourly precipitation estimation from satellite information, such as long wave infrared data. The brightness temperature data from infrared data is considered to contain cloud information. Radar stage IV dataset is used as ground measurement for parameter calibration. Stacked denoising auto-encoders (SDAE) is applied here to build a 4-layer neural network with 1000 hidden nodes for each hidden layer. SDAE involves two major steps: (1) greedily pre-training each layer as a denoising auto-encoder using the outputs of previous trained hidden layer output starting from visible layer to initialize parameters; (2) fine-tuning the whole deep neural network with supervised criteria. The results are compared with satellite precipitation product PERSIANN-CCS (Precipitation Estimation from Remotely Sensed Imagery using an Artificial Neural Network Cloud Classification System). Based on the results, we have several valuable conclusions: By properly training the neural network, it is able to extract useful information for precipitation estimation. For example, it can reduce the mean squared error of the precipitation by 58% for the summer season in the central United States of the validation period. The SDAE method captures the shape of the precipitation from the cloud shape better compared to the CCS product. Design of

  13. Global Precipitation Analysis Using Satellite Observations

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Huffman, George; Curtis, Scott; Bolvin, David; Nelkin, Eric

    2002-01-01

    Global precipitation analysis covering the last few decades and the impact of the new TRMM (Tropical Rainfall Measuring Mission) observations are reviewed in the context of weather and climate applications. All the data sets discussed are the result of mergers of information from multiple satellites and gauges, where available. The focus of the talk is on TRMM-based 3 hr. analyses that use TRMM to calibrate polar-orbit microwave observations from SSM/I (and other satellites) and geosynchronous IR observations and merges the various calibrated observations into a final, 3 hr. resolution map. This TRMM standard product will be available for the entire TRMM period (January 1998-present) at the end of 2002. A real-time version of this merged product is being produced and is available at 0.25 deg latitude-longitude resolution over the latitude range from 50 deg N-50 deg S. Examples will be shown, including its use in monitoring flood conditions and in relating weather-scale patterns to climate-scale patterns. The 3-hourly analysis is placed in the context of two research products of the World Climate Research Program's (WCRP/GEWEX) Global Precipitation Climatology Project (GPCP). The first is the 23 year, monthly, globally complete precipitation analysis that is used to explore global and regional variations and trends and is compared to the much shorter TRMM tropical data set. The GPCP data set shows no significant global trend in precipitation over the twenty years, unlike the positive trend in global surface temperatures over the past century. Regional trends are also analyzed. A trend pattern that is a combination of both El Nino and La Nina precipitation features is evident in the Goodyear data set. This pattern is related to an increase with time in the number of combined months of El Nino and La Nina during the 23 year period. Monthly anomalies of precipitation are related to ENSO variations with clear signals extending into middle and high latitudes of both

  14. Climate-crop relationships: precipitation or temperature?

    NASA Astrophysics Data System (ADS)

    Rowhani, P.; Martin, W.; Iglesias, A.; Hertel, T. W.

    2011-12-01

    Large uncertainties prevail in the estimates of the impacts of climate change on agriculture. Whether agricultural production will suffer from changes in temperature or precipitation is also not well understood. With over 1 billion undernourished people in the world we need to improve our understanding of the climatic controls on crop production since the situation may get worse with the predicted change in climate. To help mitigation and adaptation efforts, we need to be able to better distinguish the various factors influencing crop production. This requires reducing uncertainties related to data and inherent to the models. To this end, a comparison between different models measuring the impacts of precipitation and temperature on maize production in Tanzania is presented here. Results from a statistical analysis will be compared to crop yields estimated by DSSAT (Decision Support System for Agrotechnology Transfer). Currently, agriculture in Tanzania represents around 46% of its GDP, and is mainly rainfed with little chemical input, making crop production very sensitive and vulnerable to climate. The analysis focuses on the six major maize producing regions (Iringa, Mbeya, Rukwa, Ruvuma, Arusha, and Shinyanga) with an average production of 1.1 Mtonnes/year and a yield of 1.55 tonnes/ha over the 1992-2005 time period. Future climate will be based on the results from 22 Global Circulation Models using the A2 scenario. First results show that different climatic factors seem to play a key role in maize yield depending on the method used. Using statistical models, temperature is a major factor impacting crop yields whereas precipitation has a major influence on yields using the process-based model, DSSAT. With the predicted changes in climate by the IPCC, this study will give insight on the potential impacts on crop production, and highlight key uncertainties that need to be reduced.

  15. Evaluation of satellite-retrieved extreme precipitation rates across the central United States

    NASA Astrophysics Data System (ADS)

    Aghakouchak, A.; Behrangi, A.; Sorooshian, S.; Hsu, K.; Amitai, E.

    2011-01-01

    Water resources management, forecasting, and decision making require reliable estimates of precipitation. Extreme precipitation events are of particular importance because of their severe impact on the economy, the environment, and the society. In recent years, the emergence of various satellite-retrieved precipitation products with high spatial resolutions and global coverage have resulted in new sources of uninterrupted precipitation estimates. However, satellite-based estimates are not well integrated into operational and decision-making applications because of a lack of information regarding the associated uncertainties and reliability of these products. In this study, four satellite-derived precipitation products (CMORPH, PERSIANN, TMPA-RT, and TMPA-V6) are evaluated with respect to their performance in capturing precipitation extremes. The Stage IV (radar-based, gauge-adjusted) precipitation estimates are used as reference data. The results show that with respect to the probability of detecting extremes and the volume of correctly identified precipitation, CMORPH and PERSIANN data sets lead to better estimates. However, their false alarm ratio and volume are higher than those of TMPA-RT and TMPA-V6. Overall, no single precipitation product can be considered ideal for detecting extreme events. In fact, all precipitation products tend to miss a significant volume of rainfall. With respect to verification metrics used in this study, the performance of all satellite products tended to worsen as the choice of extreme precipitation threshold increased. The analyses suggest that extensive efforts are necessary to develop algorithms that can capture extremes more reliably.

  16. NASA's Global Precipitation Mission Ground Validation Segment

    NASA Technical Reports Server (NTRS)

    Schwaller, Mathew R

    2005-01-01

    NASA is designing a Ground Validation Segment (GVS) as one of its contributions to the Global Precipitation Measurement (GPM) mission. The GPM GVS provides an independent means for evaluation, diagnosis, and ultimately improvement of the GPM spaceborne measurements and precipitation products. NASA's GPM GVS concept calls for a combination of direct observations executed within a Multidimensional Observing Volume (MOV) and model-based analyses executed by a Satellite Simulator Model (SSM). The MOV consists of ground-based instruments that measure local surface and atmospheric properties required for GPM validation. The SSM utilizes MOV measurements in a forward numerical model. The goal of the SSM forward modeling is calculation of the following properties: top-of-atmosphere microwave radiative quantities to within sensor noise of those measured by the GPM Core Satellite, precipitation quantities identical to those generated by the standard GPM precipitation retrieval algorithms, and quantitative/objective error estimates of both sets of quantities. At present, the GVS is in the early design stage and various scenarios have been generated to assess how it will be used in the GPM era. The GPM GVS will be operational in the year prior to the launch of the GPM core satellite, which has a launch date scheduled for December 2010.

  17. Investigating satellite precipitation uncertainties over a mountainous area in the eastern Italian Alps

    NASA Astrophysics Data System (ADS)

    Maggioni, V.; Nikolopoulos, E. I.; Anagnostou, E. N.; Borga, M., Sr.

    2015-12-01

    Accurate quantitative precipitation estimation over mountainous basins is of great importance because of their susceptibility to hazards such as flash floods, shallow landslides, and debris flows, triggered by heavy precipitation events. In situ observations over mountainous areas are limited, but currently available satellite precipitation products are able to provide precipitation estimates over those areas. However, uncertainties in satellite precipitation estimates still represent the main limitation in utilizing these products in hydrological applications. Therefore, quantifying the uncertainty in satellite precipitation products is necessary for enabling an improved use of those products. The study is conducted on the Trentino Alto-Adige region, located in the eastern Italian Alps. Rainfall observations for a 10-yr period (2000-2009) derived from a dense rain gauge network in the region are used as reference. A number of satellite precipitation error properties, typically used in error modeling, are investigated and include the probability of detection, false alarm rates, missed events, spatial correlation of the error, and hit biases are investigated as a function of seasonality, satellite precipitation algorithm, satellite rainfall rate, gauge density, and temporal resolution. Three widely used satellite-based precipitation products are employed: 1) the Climate Prediction Center morphing (CMORPH) product; 2) the Precipitation Estimation from Remotely Sensed Imagery Using Artificial Neural Networks (PERSIANN); and 3) the TRMM Multisatellite Precipitation Analysis (TMPA) 3B42 near-real time product (3B42-RT). These products are the ones on which the new GPM level-3 precipitation product - IMERG - algorithm is based upon. Therefore, a better understanding of uncertainties associated with each single product is fundamental for improving error modeling of this merged satellite precipitation algorithm over complex terrain regions.

  18. BOTANICAL ASPECTS OF ACIDIC PRECIPITATION

    EPA Science Inventory

    Acidic precipitation can be characterized as wet or frozen atmospheric deposition with a hydrogen ion concentration greater than 2.5 microequivalents liter-1. Acidic precipitation is perceived as a significant air pollution problem derived chiefly from combustion of fossil fuels,...

  19. Improved ethanol precipitation of DNA.

    PubMed

    Fregel, Rosa; González, Ana; Cabrera, Vicente M

    2010-04-01

    In this Short Communication, a shorter version of the standard DNA ethanol precipitation and purification protocol is described. It uses a mixture of 70% ethanol, 75 mM ammonium acetate and different concentrations of different carriers to perform DNA precipitation and washing in only one step. PMID:20336673

  20. Precipitation Process and Apparatus Therefor

    DOEpatents

    Stang, Jr, L C

    1950-12-05

    This invention concerns an apparatus for remotely-controlled precipitation and filtration operations. Liquid within a precipitation chamber is maintained above a porous member by introducing air beneath the member; pressure beneath the porous member is reduced to suck the liquid through the member and effect filtration.

  1. Acid precipitation in historical perspective

    SciTech Connect

    Cowling, E.B.

    1982-02-01

    The history of acid precipitation is traced from the first awareness of the problem in the mid-17th century to the present. An outline of the National Acid Precipitation Assessment program is also given, and the author makes recommendations for future research. (JMT)

  2. Precipitation in the Solar System

    ERIC Educational Resources Information Center

    McIntosh, Gordon

    2007-01-01

    As an astronomy instructor, I am always looking for commonly observed Earthly experiences to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote a short TPT article on frost. This paper is on the related phenomena of precipitation. Precipitation, so common on most of the Earth's…

  3. Resistivity Problems in Electrostatic Precipitation

    ERIC Educational Resources Information Center

    White, Harry J.

    1974-01-01

    The process of electrostatic precipitation has ever-increasing application in more efficient collection of fine particles from industrial air emissions. This article details a large number of new developments in the field. The emphasis is on high resistivity particles which are a common cause of poor precipitator performance. (LS)

  4. Current status of the dual-frequency precipitation radar on the global precipitation measurement core spacecraft

    NASA Astrophysics Data System (ADS)

    Furukawa, K.; Nio, T.; Konishi, T.; Oki, R.; Masaki, T.; Kubota, T.; Iguchi, T.; Hanado, H.

    2015-10-01

    The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. JAXA and NICT developed the DPR through procurement. The configuration of precipitation measurement using active radar and a passive radiometer is similar to TRMM. The major difference is that DPR is used in GPM instead of the precipitation radar (PR) in TRMM. The inclination of the core satellite is 65 degrees, and the nominal flight altitude is 407 km. The non-sun-synchronous circular orbit is necessary for measuring the diurnal change of rainfall similarly to TRMM. The DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). Both KuPR and KaPR have almost the same design as TRMM PR. The DPR system design and performance were verified through the ground test. GPM core observatory was launched at 18:37:00 (UT) on February 27, 2014 successfully. DPR orbital check out was completed in May 2014. The results of orbital checkout show that DPR meets its specification on orbit. After completion of initial checkout, DPR started Normal

  5. The Global Precipitation Climatology Centre (GPCC) - in situ observation based precipitation climatology on regional and global scale

    NASA Astrophysics Data System (ADS)

    Fuchs, T.; Schneider, U.; Rudolf, B.

    2009-04-01

    The Global Precipitation Climatology Centre (GPCC, http://gpcc.dwd.de) provides global monthly precipitation analyses for monitoring and research of the earth's climate. The centre is a German contribution to the World Climate Research Programme (WCRP), to the Global Climate Observing System (GCOS), and to the Global Earth Observation System of Systems (GEOSS). It contributes to water resources assessments, flood and drought monitoring, climate variability and trend analyses. GPCC published in year 2008 a new global precipitation climatology as well as a reanalysis of its full data base for all months of the period 1901-2007. The GPCC data base comprises monthly precipitation totals from more than 70 000 different stations in the world. It produces gridded data sets of monthly precipitation on the earth's land surface derived from raingauge based observation data. Intensive quality control of observation data and station metadata ensures a high analysis quality. The different GPCC products are adjusted to different user needs. It routinely produces 2 near real-time precipitation monitoring products. Its 2 non real-time products are updated at irregular time intervals after significant updates of its observation station database. All GPCC products can be visualised and accessed free of charge via Internet from http://gpcc.dwd.de. The GPCC First Guess Product of the monthly precipitation anomaly is based on synoptic weather reports (SYNOP) from about 6,300 stations worldwide received near real-time via the WMO Global Telecommunication System (GTS). The product is available within 5 days after end of an observation month. Main application purpose is near real-time drought monitoring. The product uses since mid 2008 the new GPCC monthly precipitation climatology as analysis background. Spatial product resolution: 1.0° and 2.5°. The GPCC Monitoring Product of monthly precipitation is based on SYNOP and monthly CLIMAT reports received near real-time via GTS from about

  6. Inter-comparison of precipitation retrievals from the Global Precipitation Measurement mission constellation.

    NASA Astrophysics Data System (ADS)

    Kidd, Chris; Matsui, Toshihisa; Randel, Dave; Stocker, Erich; Kummerow, Chris

    2015-04-01

    The Global Precipitation Measurement mission (GPM) is an international satellite mission that brings together a number of different component satellites and sensors, each contributing observations capable of providing information on precipitation. The joint US-Japan core observatory, launched on 27 February 2014, carries the GPM Microwave Imager (GMI) and the Dual-frequency Precipitation Radar (DPR). The core observatory serves as a standard against which other sensors in the constellation are calibrated, providing a consistent observational dataset to ensure the highest quality precipitation retrievals to be made. Precipitation retrievals from the constellation of partner satellites are generated through the common framework of the Goddard-PROFiling (GPROF) scheme, and is applied to both the conically-scanning sensors and the cross-track sensors; the provision of precipitation estimates from all the constellation sensors contributing to the better-than 3-hour average temporal sampling. This study focuses upon the inter-comparison of the products from the different sensors during the first year of GPM operations; March 2014-February 2015. The two regions chosen for the inter-comparison, are the United States and Western Europe, and utilize the extensive radar networks of these regions. Statistical results were generated for instantaneous precipitation retrievals for each of the constellation sensors. Results show that overall the retrievals from the cross-track observations produce higher correlations with the surface radar data sets than the retrievals from the conically-scanning observations, although they tend to have higher root-mean squared errors. Some variation in performance between the individual types of sensors is also noted, which may be attributed to assumptions within the retrieval scheme (e.g. resolution, background fields, etc); other differences require further investigation.

  7. PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINATING ELEMENTS

    DOEpatents

    Sutton, J.B.

    1958-02-18

    This patent relates to an improved method for the decontamination of plutonium. The process consists broadly in an improvement in a method for recovering plutonium from radioactive uranium fission products in aqueous solutions by decontamination steps including byproduct carrier precipitation comprising the step of introducing a preformed aqueous slurry of a hydroxide of a metal of group IV B into any aqueous acidic solution which contains the plutonium in the hexavalent state, radioactive uranium fission products contaminant and a by-product carrier precipitate and separating the metal hydroxide and by-product precipitate from the solution. The process of this invention is especially useful in the separation of plutonium from radioactive zirconium and columbium fission products.

  8. Quantification of asphaltene precipitation by scaling equation

    NASA Astrophysics Data System (ADS)

    Janier, Josefina Barnachea; Jalil, Mohamad Afzal B. Abd.; Samin, Mohamad Izhar B. Mohd; Karim, Samsul Ariffin B. A.

    2015-02-01

    Asphaltene precipitation from crude oil is one of the issues for the oil industry. The deposition of asphaltene occurs during production, transportation and separating process. The injection of carbon dioxide (CO2) during enhance oil recovery (EOR) is believed to contribute much to the precipitation of asphaltene. Precipitation can be affected by the changes in temperature and pressure on the crude oil however, reduction in pressure contribute much to the instability of asphaltene as compared to temperature. This paper discussed the quantification of precipitated asphaltene in crude oil at different high pressures and at constant temperature. The derived scaling equation was based on the reservoir condition with variation in the amount of carbon dioxide (CO2) mixed with Dulang a light crude oil sample used in the experiment towards the stability of asphaltene. A FluidEval PVT cell with Solid Detection System (SDS) was the instrument used to gain experimental knowledge on the behavior of fluid at reservoir conditions. Two conditions were followed in the conduct of the experiment. Firstly, a 45cc light crude oil was mixed with 18cc (40%) of CO2 and secondly, the same amount of crude oil sample was mixed with 27cc (60%) of CO2. Results showed that for a 45cc crude oil sample combined with 18cc (40%) of CO2 gas indicated a saturation pressure of 1498.37psi and asphaltene onset point was 1620psi. Then for the same amount of crude oil combined with 27cc (60%) of CO2, the saturation pressure was 2046.502psi and asphaltene onset point was 2230psi. The derivation of the scaling equation considered reservoir temperature, pressure, bubble point pressure, mole percent of the precipitant the injected gas CO2, and the gas molecular weight. The scaled equation resulted to a third order polynomial that can be used to quantify the amount of asphaltene in crude oil.

  9. A cluster-optimizing regression-based approach for precipitation spatial downscaling in mountainous terrain

    NASA Astrophysics Data System (ADS)

    Guan, Huade; Wilson, John L.; Xie, Hongjie

    2009-09-01

    SummaryPrecipitation temporal and spatial variability often controls terrestrial hydrological processes and states. Common remote-sensing and modeling precipitation products have a spatial resolution that is often too coarse to reveal hydrologically important spatial variability. A statistical algorithm was developed for downscaling low-resolution spatial precipitation fields. This algorithm auto-searches precipitation spatial structures (rain-pixel clusters), and orographic effects on precipitation distribution without prior knowledge of atmospheric setting. It is composed of three components: rain-pixel clustering, multivariate regression, and random cascade. The only required input data for the downscaling algorithm are coarse-pixel precipitation map and a topographic map. The algorithm was demonstrated with 4 km × 4 km Next Generation Radar (NEXRAD) precipitation fields, and tested by downscaling NEXRAD-aggregated 16 km × 16 km precipitation fields to 4 km × 4 km pixel precipitation, which was then compared to the original NEXRAD data. The demonstration and testing were performed at both daily and hourly temporal resolutions for the northern New Mexico mountainous terrain and the central Texas Hill Country. The algorithm downscaled daily precipitation fields are in good agreement with the original 4 km × 4 km NEXRAD precipitation, as measured by precipitation spatial structures and the statistics between the downscaling and the original NEXRAD precipitation maps. For three daily precipitation events, downscaled precipitation map reproduces precipitation variance of the disaggregation field, and with Pearson correlation coefficients between the downscaled map and the NEXRAD map of 0.65, 0.71, and 0.80. The algorithm does not perform as well on downscaling hourly precipitation fields at the examined scale range (from 16 km to 4 km), which underestimates precipitation variance of the disaggregation field. For a scale range from 4 km to 1 km, the algorithm has

  10. Role of bacteria in marine barite precipitation: a case study using Mediterranean seawater.

    PubMed

    Torres-Crespo, N; Martínez-Ruiz, F; González-Muñoz, M T; Bedmar, E J; De Lange, G J; Jroundi, F

    2015-04-15

    Marine bacteria isolated from natural seawater were used to test their capacity to promote barite precipitation under laboratory conditions. Seawater samples were collected in the western and eastern Mediterranean at 250 m and 200 m depths, respectively, since marine barite formation is thought to occur in the upper water column. The results indicate that Pseudoalteromonas sp., Idiomarina sp. and Alteromonas sp. actually precipitate barite under experimental conditions. Barite precipitates show typical characteristics of microbial precipitation in terms of size, morphology and composition. Initially, a P-rich phase precipitates and subsequently evolves to barite crystals with low P contents. Under laboratory conditions barite formation correlates with extracellular polymeric substances (EPS) production. Barite precipitates are particularly abundant in cultures where EPS production is similarly abundant. Our results further support the idea that bacteria may provide appropriate microenvironments for mineral precipitation in the water column. Therefore, bacterial production in the past ocean should be considered when using Ba proxies for paleoproductivity reconstructions. PMID:25647371

  11. Heavy precipitation events in northern Switzerland

    NASA Astrophysics Data System (ADS)

    Giannakaki, Paraskevi; Martius, Olivia

    2013-04-01

    Heavy precipitation events in the Alpine region often cause floods, rock-falls and mud slides with severe consequences for population and economy. Breaking synoptic Rossby waves located over western Europe, play a central role in triggering such heavy rain events in southern Switzerland (e.g. Massacand et al. 1998). In contrast, synoptic scale structures triggering heavy precipitation on the north side of the Swiss Alps and orographic effects have so far not been studied comprehensively. An observation based high resolution precipitation data set for Switzerland and the Alps (MeteoSwiss) is used to identify heavy precipitation events affecting the north side of the Swiss Alps for the time period 1961-2010. For these events a detailed statistical and dynamical analysis of the upper level flow is conducted using ECMWFs ERA-40 and ERA-Interim reanalysis data sets. For the analysis north side of the Swiss Alps is divided in two investigation areas north-eastern and western Switzerland following the Swiss climate change scenarios (Bey et al. 2011). A subjective classification of upper level structures triggering heavy precipitation events in the areas of interest is presented. Four classes are defined based on the orientation and formation of the dynamical tropopause during extreme events in the northern part of Switzerland and its sub-regions. The analysis is extended by a climatology of breaking waves and cut-offs following the method of Wernli and Sprenger (2007) to examine their presence and location during extreme events. References Bey I., Croci-Maspoli M., Fuhrer J., Kull C, Appenzeller C., Knutti R. and Schär C. Swiss Climate Change Scenarios CH2011, C2SM, MeteoSwiss, ETH, NCCR Climate, OcCC (2011), http://dx.doi.org/10.3929/ethz-a-006720559 Massacand A., H. Wernli, and H.C. Davies, 1998. Heavy precipitation on the Alpine South side: An upper-level precursor. Geophys. Res. Lett., 25, 1435-1438. MeteoSwiss 2011. Documentation of Meteoswiss grid-data products

  12. Stability of Grassland Communities to Altered Precipitation: A Meta-Analysis

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Shi, Z.; Collins, S. L.; Knapp, A.; Pockman, W.; Smith, M.

    2014-12-01

    Species-specific responses to changes in precipitation can alter plant community structure and composition potentially altering ecosystem functioning. The latter will further feed back to climate change. Here, we synthesized results from more than 50 experimental studies that either increased or decreased precipitation in grasslands to assess productivity responses of different species and plant functional types (PFT) as well as changes in community structure. Our results showed that increased precipitation enhanced aboveground net primary production (ANPP) of the dominant PFT but had no effect on ANPP of the subordinate species. Similarly, decreased precipitation reduced ANPP of the dominant species but not that of subordinate species. Individual C3 species were highly responsive to alterations in precipitation, but C4 species were not. Altered precipitation had no effect on species richness, evenness or diversity. Overall, ANPP and belowground net primary productivity (BNPP) responded to both increased and reduced precipitation, but relative responses of ANPP to increased precipitation diminished with increasing mean annual precipitation (MAP) whereas the relative responses to reduced precipitation did not change with MAP. BNPP responses to altered precipitation did not vary with MAP. Our findings suggest that the dominant PFT in grasslands can be used as a proxy for community responses in ecosystem biogeochemical models. Further, grassland community composition and structure appear to be relatively stable in response to alterations in precipitation of the duration and magnitude encompassed by these experiments.

  13. BASIC PEROXIDE PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINANTS

    DOEpatents

    Seaborg, G.T.; Perlman, I.

    1959-02-10

    A process is described for the separation from each other of uranyl values, tetravalent plutonium values and fission products contained in an aqueous acidic solution. First the pH of the solution is adjusted to between 2.5 and 8 and hydrogen peroxide is then added to the solution causing precipitation of uranium peroxide which carries any plutonium values present, while the fission products remain in solution. Separation of the uranium and plutonium values is then effected by dissolving the peroxide precipitate in an acidic solution and incorporating a second carrier precipitate, selective for plutonium. The plutonium values are thus carried from the solution while the uranium remains flissolved. The second carrier precipitate may be selected from among the group consisting of rare earth fluorides, and oxalates, zirconium phosphate, and bismuth lihosphate.

  14. Estimation of continental precipitation recycling

    NASA Technical Reports Server (NTRS)

    Brubaker, Kaye L.; Entekhabi, Dara; Eagleson, P. S.

    1993-01-01

    The total amount of water that precipitates on large continental regions is supplied by two mechanisms: 1) advection from the surrounding areas external to the region and 2) evaporation and transpiration from the land surface within the region. The latter supply mechanism is tantamount to the recycling of precipitation over the continental area. The degree to which regional precipitation is supplied by recycled moisture is a potentially significant climate feedback mechanism and land surface-atmosphere interaction, which may contribute to the persistence and intensification of droughts. Gridded data on observed wind and humidity in the global atmosphere are used to determine the convergence of atmospheric water vapor over continental regions. A simplified model of the atmospheric moisture over continents and simultaneous estimates of regional precipitation are employed to estimate, for several large continental regions, the fraction of precipitation that is locally derived. The results indicate that the contribution of regional evaporation to regional precipitation varies substantially with location and season. For the regions studied, the ratio of locally contributed to total monthly precipitation generally lies between 0. 10 and 0.30 but is as high as 0.40 in several cases.

  15. Guided Self-Assembly of Nano-Precipitates into Mesocrystals

    NASA Astrophysics Data System (ADS)

    Liu, H.; Gao, Y.; Xu, Z.; Zhu, Y. M.; Wang, Y.; Nie, J. F.

    2015-11-01

    We show by a combination of computer simulation and experimental characterization guided self-assembly of coherent nano-precipitates into a mesocrystal having a honeycomb structure in bulk materials. The structure consists of different orientation variants of a product phase precipitated out of the parent phase by heterogeneous nucleation on a hexagonal dislocation network. The predicted honeycomb mesocrystal has been confirmed by experimental observations in an Mg-Y-Nd alloy. The structure and lattice parameters of the mesocrystal and the size of the nano-precipitates are readily tuneable, offering ample opportunities to tailor its properties for a wide range of technological applications.

  16. Guided Self-Assembly of Nano-Precipitates into Mesocrystals

    PubMed Central

    Liu, H.; Gao, Y.; Xu, Z.; Zhu, Y.M.; Wang, Y.; Nie, J.F.

    2015-01-01

    We show by a combination of computer simulation and experimental characterization guided self-assembly of coherent nano-precipitates into a mesocrystal having a honeycomb structure in bulk materials. The structure consists of different orientation variants of a product phase precipitated out of the parent phase by heterogeneous nucleation on a hexagonal dislocation network. The predicted honeycomb mesocrystal has been confirmed by experimental observations in an Mg-Y-Nd alloy. The structure and lattice parameters of the mesocrystal and the size of the nano-precipitates are readily tuneable, offering ample opportunities to tailor its properties for a wide range of technological applications. PMID:26559002

  17. STAMMEX high resolution gridded daily precipitation dataset over Germany: a new potential for regional precipitation climate research

    NASA Astrophysics Data System (ADS)

    Zolina, Olga; Simmer, Clemens; Kapala, Alice; Mächel, Hermann; Gulev, Sergey; Groisman, Pavel

    2014-05-01

    We present new high resolution precipitation daily grids developed at Meteorological Institute, University of Bonn and German Weather Service (DWD) under the STAMMEX project (Spatial and Temporal Scales and Mechanisms of Extreme Precipitation Events over Central Europe). Daily precipitation grids have been developed from the daily-observing precipitation network of DWD, which runs one of the World's densest rain gauge networks comprising more than 7500 stations. Several quality-controlled daily gridded products with homogenized sampling were developed covering the periods 1931-onwards (with 0.5 degree resolution), 1951-onwards (0.25 degree and 0.5 degree), and 1971-2000 (0.1 degree). Different methods were tested to select the best gridding methodology that minimizes errors of integral grid estimates over hilly terrain. Besides daily precipitation values with uncertainty estimates (which include standard estimates of the kriging uncertainty as well as error estimates derived by a bootstrapping algorithm), the STAMMEX data sets include a variety of statistics that characterize temporal and spatial dynamics of the precipitation distribution (quantiles, extremes, wet/dry spells, etc.). Comparisons with existing continental-scale daily precipitation grids (e.g., CRU, ECA E-OBS, GCOS) which include considerably less observations compared to those used in STAMMEX, demonstrate the added value of high-resolution grids for extreme rainfall analyses. These data exhibit spatial variability pattern and trends in precipitation extremes, which are missed or incorrectly reproduced over Central Europe from coarser resolution grids based on sparser networks. The STAMMEX dataset can be used for high-quality climate diagnostics of precipitation variability, as a reference for reanalyses and remotely-sensed precipitation products (including the upcoming Global Precipitation Mission products), and for input into regional climate and operational weather forecast models. We will present

  18. Smoothed Particle Hydrodynamics Model for Reactive Transport and Mineral Precipitation

    SciTech Connect

    Tartakovsky, Alexandre M.; Scheibe, Timothy D.; Redden, George; Meakin, Paul; Fang, Yilin

    2006-06-30

    A new Lagrangian particle model based on smoothed particle hydrodynamics was used to simulate pore scale precipitation reactions. The side-by-side injection of reacting solutions into two halves of a two-dimensional granular porous medium was simulated. Precipitation on grain surfaces occurred along a narrow zone in the middle of the domain, where the reacting solutes mixed to generate a supersaturated reaction product. The numerical simulations qualitatively reproduced the behavior observed in related laboratory experiments.

  19. Precipitation Measurements from Space: The Global Precipitation Measurement Mission

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2007-01-01

    Water is fundamental to the life on Earth and its phase transition between the gaseous, liquid, and solid states dominates the behavior of the weather/climate/ecological system. Precipitation, which converts atmospheric water vapor into rain and snow, is central to the global water cycle. It regulates the global energy balance through interactions with clouds and water vapor (the primary greenhouse gas), and also shapes global winds and dynamic transport through latent heat release. Surface precipitation affects soil moisture, ocean salinity, and land hydrology, thus linking fast atmospheric processes to the slower components of the climate system. Precipitation is also the primary source of freshwater in the world, which is facing an emerging freshwater crisis in many regions. Accurate and timely knowledge of global precipitation is essential for understanding the behavior of the global water cycle, improving freshwater management, and advancing predictive capabilities of high-impact weather events such as hurricanes, floods, droughts, and landslides. With limited rainfall networks on land and the impracticality of making extensive rainfall measurements over oceans, a comprehensive description of the space and time variability of global precipitation can only be achieved from the vantage point of space. This presentation will examine current capabilities in space-borne rainfall measurements, highlight scientific and practical benefits derived from these observations to date, and provide an overview of the multi-national Global Precipitation Measurement (GPM) Mission scheduled to bc launched in the early next decade.

  20. Silica Precipitation and Lithium Sorption

    SciTech Connect

    Jay Renew

    2015-09-20

    This file contains silica precipitation and lithium sorption data from the project. The silica removal data is corrected from the previous submission. The previous submission did not take into account the limit of detection of the ICP-MS procedure.

  1. Electrical precipitation apparatus and method

    SciTech Connect

    Furlong, D.A.

    1984-11-06

    An electrostatic precipitator having improved collection efficiency for suspended particles having either high or low electrical resistivities is provided. The precipitator utilizes porous collecting surfaces which permit passage of gas while retaining suspended particles and means are provided to create an electrostatic field causing the particles to migrate toward the collecting surfaces. According to the invention, only a portion of the inlet gas flow to the precipitator, sufficient to provide aerodynamic forces to facilitate adherence of the particles to the collecting surface, is drawn through the porous collecting surfaces with the remainder of the gas flow being essentially parallel to such surfaces. The two gas streams are separately withdrawn and may be combined to provide a clean gas effluent. The invention also provides an improved method for removing suspended particles from gases by electrical precipitation.

  2. Evaluation of Coupled Precipitator Two

    SciTech Connect

    Stone, M.E.

    1999-11-08

    The offline testing of the Coupled Precipitator Two (CP-2) has been completed. The tests were conducted and are documented. The tests were conducted at an offline test rack near the Drain Tube Test Stand facility in 672-T.

  3. Identifying Anomality in Precipitation Processes

    NASA Astrophysics Data System (ADS)

    Jiang, P.; Zhang, Y.

    2014-12-01

    Safety, risk and economic analyses of engineering constructions such as storm sewer, street and urban drainage, and channel design are sensitive to precipitation storm properties. Whether the precipitation storm properties exhibit normal or anomalous characteristics remains obscure. In this study, we will decompose a precipitation time series as sequences of average storm intensity, storm duration and interstorm period to examine whether these sequences could be treated as a realization of a continuous time random walk with both "waiting times" (interstorm period) and "jump sizes" (average storm intensity and storm duration). Starting from this viewpoint, we will analyze the statistics of storm duration, interstorm period, and average storm intensity in four regions in southwestern United States. We will examine whether the probability distribution is temporal and spatial dependent. Finally, we will use fractional engine to capture the randomness in precipitation storms.

  4. Some Statistics of Instantaneous Precipitation.

    NASA Astrophysics Data System (ADS)

    Jones, Douglas M. A.; Wendland, Wayne M.

    1984-09-01

    Known sources of data from arrays of instantaneous precipitation intensity recorders in southern Germany, east-central Illinois, northeastern Illinois, central Florida, and Hilo, Hawaii are obtained. These data are analyzed for line averages of the percent frequency of occurrence of the exceedance of selected threshold precipitation intensities. The correlation coefficients of the precipitation intensity at sites at varying distances from a reference site are determined. The decay in correlation is found to be a function of climatic region and the type of precipitation: showery or continuous. Showery rains are found to be essentially uncorrelated about 12 km from the reference site while continuous rain exhibits no correlation beyond about 50 km.Single-station intensity data collected at Urbana, Illinois; Paris, France; Inyanga, Zimbabwe; Bogor, Indonesia; Reading, United Kingdom; Island Beach, New Jersey; Miami, Florida; Franklin, North Carolina; and Majuro, Marshall Islands, are compared.

  5. Heavy Precipitation Events in Lithuania

    NASA Astrophysics Data System (ADS)

    Bukantis, A.; Rimkus, E.; Kažys, J.

    2010-09-01

    Analysis of heavy precipitation events in Lithuania is presented in this work. Research was divided into two parts. Spatial distribution and dynamic of heavy precipitation events in Lithuania during observation period (1961-2008) is presented in the first part and climate predictions for XXI century according to outputs of CCLM model are in the second. Daily data from 17 meteorological stations were used for the analysis of heavy precipitation events in Lithuania. Research covers period from 1961 to 2008. Annual and seasonal heavy precipitation values and the recurrence of extreme daily and 3-day precipitation events were analyzed. Spatial distribution of heavy precipitation events in Lithuania was determined; the trends of such precipitation recurrence were identified. Also, daily and 3-day annual maxima probabilities were calculated using the Generalized Extreme Value (GEV) distribution. 10, 30 and 100 years return period was analyzed. Finally, atmospheric circulation processes during heavy precipitation events were described using the adapted Hess & Brezowski macrocirculation form classification Predictions of changes of heavy precipitation recurrence in Lithuania are also presented in this study. Output data of the regional climate model CCLM (COSMO - Climate Limited-area Model) for the period 1971-2100 were used. Predictions were based on A1B and B1 emission scenarios. Despite of relatively small area and quite negligible differences in altitude there are significant unevenness in spatial distribution of heavy precipitation events in Lithuania. The mean annual number of cases when daily precipitation amount exceeded 10 mm fluctuates from 12.4 to 21.9 and from 5.3 to 10.5 when 3-day precipitation exceeded 20 mm. The probability of maximum precipitation amount for 10 year return period appears very familiar to spatial distribution of heavy precipitation recurrence: the highest values can be expected in the western part (55-60 mm daily and 75-85 mm in 3-days

  6. Environmental Radioactivity, Temperature, and Precipitation.

    ERIC Educational Resources Information Center

    Riland, Carson A.

    1996-01-01

    Reports that environmental radioactivity levels vary with temperature and precipitation and these effects are due to radon. Discusses the measurement of this environmental radioactivity and the theory behind it. (JRH)

  7. The 2014 Silba Precipitation Extreme

    NASA Astrophysics Data System (ADS)

    Rasol, Dubravka; Ólafsson, Haraldur

    2015-04-01

    On 30 July 2014 a 24 h precipitation record of 218 mm was set at the island of Silba in the N-Adriatic Sea. The precipitation was of convective nature and significantly less precipitation was recorded only small distances away, at the coast of mainland Croatia. The event is reproduced numerically and discussed in terms of dynamics and predictability. On a large scale, the precipitation extreme was associated with a slow-moving upper tropospheric low that formed over the N-Atlantic several days earlier. At lower levels, there were humid mediterranean airmasses. On a smaller scale, there are indications that the extreme convection may have been triggered by an orographic disturbance.

  8. NASA's Global Precipitation Measurement (GPM) Mission for Science and Society

    NASA Astrophysics Data System (ADS)

    Jackson, Gail

    2016-04-01

    Water is fundamental to life on Earth. Knowing where and how much rain and snow falls globally is vital to understanding how weather and climate impact both our environment and Earth's water and energy cycles, including effects on agriculture, fresh water availability, and responses to natural disasters. The Global Precipitation Measurement (GPM) Mission, launched February 27, 2014, is an international satellite mission to unify and advance precipitation measurements from a constellation of research and operational sensors to provide "next-generation" precipitation products. The joint NASA-JAXA GPM Core Observatory serves as the cornerstone and anchor to unite the constellation radiometers. The GPM Core Observatory carries a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). Furthermore, since light rain and falling snow account for a significant fraction of precipitation occurrence in middle and high latitudes, the GPM instruments extend the capabilities of the TRMM sensors to detect falling snow, measure light rain, and provide, for the first time, quantitative estimates of microphysical properties of precipitation particles. As a science mission with integrated application goals, GPM is designed to (1) advance precipitation measurement capability from space through combined use of active and passive microwave sensors, (2) advance the knowledge of the global water/energy cycle and freshwater availability through better description of the space-time variability of global precipitation, and (3) improve weather, climate, and hydrological prediction capabilities through more accurate and frequent measurements of instantaneous precipitation rates and time-integrated rainfall accumulation. Since launch, the instruments have been collecting outstanding precipitation data. New scientific insights resulting from GPM data, an overview of the GPM mission concept and science activities in the United States

  9. Evaluation of extreme precipitation estimates from TRMM in Angola

    NASA Astrophysics Data System (ADS)

    Pombo, Sandra; de Oliveira, Rodrigo Proença

    2015-04-01

    In situ ground observation measurement of precipitation is difficult in vast and sparsely populated areas, with poor road networks. This paper examines the use of remote sensors installed in satellites and evaluates the accuracy of TRMM 3B42 annual maximum daily precipitation estimates in Angola, in West Africa, a region where ground monitoring networks are generally. TRMM 3B42 estimates of annual maximum daily precipitation are compared to ground observation data from 159 locations. As a direct comparison between the two datasets for a common specific period and sites is not possible, a statistical approach was adopted to test the hypothesis that the TRMM 3B42 estimates and the ground monitoring records exhibit similar statistical characteristics. The study shows that the annual maximum daily precipitation estimates obtained from TRMM 3B42 slightly underestimate the quantiles obtained from the in situ observations. The use of remote sensing products to estimate extreme precipitation values for engineering design purposes is however promising. A maximum daily precipitation map for a return period of 20 years was computed and in the future, as the length of the remote sensing data series increases, it may be possible to estimate annual maximum daily precipitation estimates exclusively from these datasets for larger return periods. The paper also presents maps of the PdT/PDT ratios, where PdT is the annual maximum precipitation for a duration d and a return period of T years, and PDT is the annual maximum daily precipitation for a return period of T years. In conjunction with these maps it is possible to estimate the maximum precipitation for durations between 3 h and 5 days.

  10. Oceanic Precipitation Measurement - Surface Validation

    NASA Astrophysics Data System (ADS)

    Klepp, Christian

    2013-04-01

    State-of-the-art satellite derived and reanalysis based precipitation climatologies still show remarkably large differences in frequency, amount, intensity, variability and temporal behavior of precipitation over the oceans. Additionally so far appropriate in-situ validation instruments were not available for shipboard use. The uncertainties are largest for light precipitation within the ITCZ and subtropics and for cold season high-latitude precipitation including mix-phase and snowfall. Hence, a long-term issue on which IPWG and GPM-GV is urging more attention is the provision of high quality surface validation data in oceanic areas using innovative ship-based instruments. Precipitation studies would greatly benefit from systematic dataset collection and analysis as such data could also be used to constrain precipitation retrievals. To achieve this goal, the KlimaCampus and Max Planck Institute for Meteorology in Hamburg, Germany funded this project that uses automated shipboard optical disdrometers, called Eigenbrodt ODM470, that are capable of measuring liquid and solid precipitation using drop size distributions in minute intervals on moving ships with high accuracy even under high wind speeds and rough sea states. Since the project start in 2009 the statistical basis for a conclusive validation has significantly improved with comprehensive data collection of more than 3 million minutes of precipitation measurements onboard six ships. Currently, six ODM470 instrument systems are available of which three are long-term mounted onboard the German research icebreaker R/V Polarstern (Alfred Wegner Institut) since June 2010, on R/V Akademik Ioffe (P.P.Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia) since September 2010 and on R/V Maria S. Merian (Brise Research, University of Hamburg) since December 2011. Three instruments are used for additional short-term shipboard campaigns and intercomparison projects. The core regions for these

  11. Impact on watershed resilience due to variation of precipitation

    NASA Astrophysics Data System (ADS)

    Kaur, H.; Kumar, P.

    2013-12-01

    values of precipitation as a noise. The methodology of this analysis can be used to determine the extent to which current high rates of sediment production in Minnesota River basin are influenced by precipitation variation.

  12. Status of high-latitude precipitation estimates from observations and reanalyses

    NASA Astrophysics Data System (ADS)

    Behrangi, Ali; Christensen, Matthew; Richardson, Mark; Lebsock, Matthew; Stephens, Graeme; Huffman, George J.; Bolvin, David; Adler, Robert F.; Gardner, Alex; Lambrigtsen, Bjorn; Fetzer, Eric

    2016-05-01

    An intercomparison of high-latitude precipitation characteristics from observation-based and reanalysis products is performed. In particular, the precipitation products from CloudSat provide an independent assessment to other widely used products, these being the observationally based Global Precipitation Climatology Project (GPCP), Global Precipitation Climatology Centre, and Climate Prediction Center Merged Analysis of Precipitation (CMAP) products and the ERA-Interim, Modern-Era Retrospective Analysis for Research and Applications (MERRA), and National Centers for Environmental Prediction-Department of Energy Reanalysis 2 (NCEP-DOE R2) reanalyses. Seasonal and annual total precipitation in both hemispheres poleward of 55° latitude are considered in all products, and CloudSat is used to assess intensity and frequency of precipitation occurrence by phase, defined as rain, snow, or mixed phase. Furthermore, an independent estimate of snow accumulation during the cold season was calculated from the Gravity Recovery and Climate Experiment. The intercomparison is performed for the 2007-2010 period when CloudSat was fully operational. It is found that ERA-Interim and MERRA are broadly similar, agreeing more closely with CloudSat over oceans. ERA-Interim also agrees well with CloudSat estimates of snowfall over Antarctica where total snowfall from GPCP and CloudSat is almost identical. A number of disagreements on regional or seasonal scales are identified: CMAP reports much lower ocean precipitation relative to other products, NCEP-DOE R2 reports much higher summer precipitation over Northern Hemisphere land, GPCP reports much higher snowfall over Eurasia, and CloudSat overestimates precipitation over Greenland, likely due to mischaracterization of rain and mixed-phase precipitation. These outliers are likely unrealistic for these specific regions and time periods. These estimates from observations and reanalyses provide useful insights for diagnostic assessment of

  13. Extreme Precipitation and High-Impact Landslides

    NASA Technical Reports Server (NTRS)

    Kirschbaum, Dalia; Adler, Robert; Huffman, George; Peters-Lidard, Christa

    2012-01-01

    It is well known that extreme or prolonged rainfall is the dominant trigger of landslides; however, there remain large uncertainties in characterizing the distribution of these hazards and meteorological triggers at the global scale. Researchers have evaluated the spatiotemporal distribution of extreme rainfall and landslides at local and regional scale primarily using in situ data, yet few studies have mapped rainfall-triggered landslide distribution globally due to the dearth of landslide data and consistent precipitation information. This research uses a newly developed Global Landslide Catalog (GLC) and a 13-year satellite-based precipitation record from Tropical Rainfall Measuring Mission (TRMM) data. For the first time, these two unique products provide the foundation to quantitatively evaluate the co-occurence of precipitation and rainfall-triggered landslides globally. The GLC, available from 2007 to the present, contains information on reported rainfall-triggered landslide events around the world using online media reports, disaster databases, etc. When evaluating this database, we observed that 2010 had a large number of high-impact landslide events relative to previous years. This study considers how variations in extreme and prolonged satellite-based rainfall are related to the distribution of landslides over the same time scales for three active landslide areas: Central America, the Himalayan Arc, and central-eastern China. Several test statistics confirm that TRMM rainfall generally scales with the observed increase in landslide reports and fatal events for 2010 and previous years over each region. These findings suggest that the co-occurrence of satellite precipitation and landslide reports may serve as a valuable indicator for characterizing the spatiotemporal distribution of landslide-prone areas in order to establish a global rainfall-triggered landslide climatology. This research also considers the sources for this extreme rainfall, citing

  14. NASA Dual Precipitation Radar Arrives at Goddard

    NASA Video Gallery

    The Dual-frequency Precipitation Radar (DPR) built by the Japan Aerospace Exploration Agency (JAXA) for the Global Precipitation Measurement (GPM) mission's Core Observatory arrived on Friday, Marc...

  15. Discontinuous precipitation in cobalt-tungsten alloys

    SciTech Connect

    Zieba, P.; Cliff, G.; Lorimer, G.W.

    1997-05-01

    Discontinuous precipitation in a Co32 wt% W alloy aged in the temperature range from 875 K to 1025 K has been investigated. Philips EM 430 STEM has been used to characterize the microstructure and to measure the composition profiles across individual lamellae of {epsilon}{sub Co} and Co{sub 3} W phases in partially transformed specimens. Two kinds of cellular precipitates have been found in the alloy. The initial transformation product, identified as primary lamellae with spacing of a few nanometers is replaced during prolonged ageing by secondary lamellae with a much larger interlamellar spacing, typically a few tens of nm. Line scans across cell boundaries of the primary lamellae revealed that, just behind the advancing cell boundary, the solute content is far from the equilibrium state. This solute excess within the cells is quickly removed at the ageing temperature. Calculations show that the diffusion process was too rapid to be identified as ordinary volume diffusion. Investigation of the kinetics showed that discontinuous precipitation is controlled by diffusion processes at the advancing cell boundary. This proposal has been confirmed by STEM analysis of tungsten profiles in the depleted {epsilon}{sub Co} lamellae.

  16. What does CloudSat reveal about global land precipitation detection by other spaceborne sensors?

    NASA Astrophysics Data System (ADS)

    Behrangi, Ali; Tian, Yudong; Lambrigtsen, Bjorn H.; Stephens, Graeme L.

    2014-06-01

    Current orbital land precipitation products have serious shortcomings in detecting light rain and snowfall, the most frequent types of global precipitation. The missed precipitation is then propagated into the merged precipitation products that are widely used. Precipitation characteristics such as frequency and intensity and their regional distribution are expected to change in a warming climate. It is important to accurately capture those characteristics to understand and model the current state of the Earth's climate and predict future changes. In this work, the precipitation detection performance of a suite of precipitation sensors, commonly used in generating the merged precipitation products, are investigated. The high sensitivity of CloudSat Cloud Profiling Radar (CPR) to liquid and frozen hydrometeors enables superior estimates of light rainfall and snowfall within 80°S-80°N. Three years (2007-2009) of CloudSat precipitation data were collected to construct a climatology reference for guiding our analysis. In addition, auxiliary data such as infrared brightness temperature, surface air temperature, and cloud types were used for a more detailed assessment. The analysis shows that no more than 50% of the tropical (40°S-40°N) precipitation occurrence is captured by the current suite of precipitation measuring sensors. Poleward of 50° latitude, a combination of various factors such as an abundance of light rainfall, snowfall, shallow precipitation-bearing clouds, and frozen surfaces reduces the space-based precipitation detection rate to less than 20%. This shows that for a better understanding of precipitation from space, especially at higher latitudes, there is a critical need to improve current precipitation retrieval techniques and sensors.

  17. Advanced Microwave Precipitation Radiometer (AMPR) for remote observation of precipitation

    NASA Technical Reports Server (NTRS)

    Galliano, J. A.; Platt, R. H.

    1990-01-01

    The design, development, and tests of the Advanced Microwave Precipitation Radiometer (AMPR) operating in the 10 to 85 GHz range specifically for precipitation retrieval and mesoscale storm system studies from a high altitude aircraft platform (i.e., ER-2) are described. The primary goals of AMPR are the exploitation of the scattering signal of precipitation at frequencies near 10, 19, 37, and 85 GHz together to unambiguously retrieve precipitation and storm structure and intensity information in support of proposed and planned space sensors in geostationary and low earth orbit, as well as storm-related field experiments. The development of AMPR will have an important impact on the interpretation of microwave radiances for rain retrievals over both land and ocean for the following reasons: (1) A scanning instrument, such as AMPR, will allow the unambiguous detection and analysis of features in two dimensional space, allowing an improved interpretation of signals in terms of cloud features, and microphysical and radiative processes; (2) AMPR will offer more accurate comparisons with ground-based radar data by feature matching since the navigation of the ER-2 platform can be expected to drift 3 to 4 km per hour of flight time; and (3) AMPR will allow underflights of the SSM/I satellite instrument with enough spatial coverage at the same frequencies to make meaningful comparisons of the data for precipitation studies.

  18. Degradable starch nanoparticle assisted ethanol precipitation of DNA.

    PubMed

    Ip, Alexander C-F; Tsai, Tsung Hao; Khimji, Imran; Huang, Po-Jung Jimmy; Liu, Juewen

    2014-09-22

    Precipitation of DNA from a large volume of aqueous solution is an important step in many molecular biology and analytical chemistry experiments. Currently, this is mainly achieved by ethanol precipitation, where a long-term incubation (usually overnight) at low temperature of -20 to -80°C with high salt concentration is required. This method also requires a large quantity of DNA to form a visible pellet and was tested mainly for double-stranded DNA. To improve DNA precipitation, co-precipitating polymers such as linear polyacrylamide has been used. In this work, we report that starch nanoparticles (SNPs) can achieve convenient DNA precipitation at room temperature with a low salt concentration and short incubation time. This method requires as low as 0.01-0.1% SNPs and can precipitate both single- and double-stranded DNA of various lengths. The effect of salt concentration, pH and the crosslinking density of SNPs has been systematically studied. Compared to other types of precipitating agents, SNPs are highly biocompatible and can be degraded by a common enzyme (amylase). This work suggests a novel application of a bio-based material that is prepared in mass production. PMID:24906766

  19. Precipitation in topographically diverse regions

    NASA Astrophysics Data System (ADS)

    Tarboton, David

    A 1991 AGU Fall Meeting session, Precipitation in Topographically Diverse Regions, focused on the understanding and modeling of precipitation in regions with significant topography, concentrating on the effect of topography on precipitation. Contributions ranged from detailed mesoscale atmospheric models to statistical approaches.Two papers presented detailed physical modeling. A. P. Barros and D. P. Lettenmaier described their work, consisting of a threedimensional finite element model based on the measurement of moist static energy. Application of the model in the Olympic and Cascades mountains demonstrated its potential to model monthly precipitation totals to within 15%. F. Giorgi described some of the work being done at NCAR that is focusing on the regional impacts of global climate change. This work uses a mesoscale meteorological model (Penn State/NCAR MM4) embedded within a general circulation model. There were three papers from the USGS/Colorado State group that described work involving the RHEA-CSU orographic precipitation model that has been coupled with the USGS/s distributed parameter Precipitation Runoff Modeling System (PRMS). The orographic precipitation model has been integrated into a geographic information system to facilitate the use of digital elevation data. The PRMS is based on the concept of hydrologic response units, and the results presented illustrated the scale's sensitivity to these. When rectangular boxes were used instead of the usual response units defined by streams and drainage divides, there was no appreciable degradation in the quality of the simulation. The size and number of response units appears to be more crucial than whether they are demarcated by drainage divides and streams or simply arbitrary.

  20. Chemical Data for Precipitate Samples

    USGS Publications Warehouse

    Foster, Andrea L.; Koski, Randolph A.

    2008-01-01

    During studies of sulfide oxidation in coastal areas of Prince William Sound in 2005, precipitate samples were collected from onshore and intertidal locations near the Ellamar, Threeman, and Beatson mine sites (chapter A, fig. 1; table 7). The precipitates include jarosite and amorphous Fe oxyhydroxide from Ellamar, amorphous Fe oxyhydroxide from Threeman, and amorphous Fe oxyhydroxide, ferrihydrite, and schwertmannite from Beatson. Precipitates occurring in the form of loose, flocculant coatings were harvested using a syringe and concentrated in the field by repetitive decanting. Thicker accumulations were either scraped gently from rocks using a stainless steel spatula or were scooped directly into receptacles (polyethylene jars or plastic heavy-duty zippered bags). Most precipitate samples contain small amounts of sedimentary detritus. With three jarosite-bearing samples from Ellamar, an attempt was made to separate the precipitate from the heavy-mineral fraction of the sediment. In this procedure, the sample was stirred in a graduated cylinder containing deionized water. The jarosite-rich suspension was decanted onto analytical filter paper and air dried before analysis. Eleven precipitate samples from the three mine sites were analyzed in laboratories of the U.S. Geological Survey (USGS) in Denver, Colorado (table 8). Major and trace elements were determined by inductively coupled plasma-mass spectrometry following multiacid (HCl-HNO3-HClO4-HF) digestion (Briggs and Meier, 2002), except for mercury, which was analyzed by cold-vapor atomic absorption spectroscopy (Brown and others, 2002a). X-ray diffraction (XRD) analyses were performed on powdered samples (<200 mesh) by S. Sutley of the USGS. Additional details regarding sample preparation and detection limits are found in Taggert (2002). Discussions of the precipitate chemistry and associated microbial communities are presented in Koski and others (2008) and Foster and others (2008), respectively.

  1. Molecular thermodynamics for prevention of asphaltene precipitation

    SciTech Connect

    Wu, Jianzhong; Prausnitz, J.M.

    1996-06-01

    Crude petroleum is a complex mixture of compounds with different chemical structures and molecular weights. Asphaltenes, the heaviest and most polar fraction of crude oil, are insoluble in normal alkanes such as n-heptane, but they are soluble in aromatic solvents such as toluene. The molecular nature of asphaltenes and their role in production and processing of crude oils have been the topic of numerous studies. Under some conditions, asphaltenes precipitate from a petroleum fluid, causing severe problems in production and transportation Our research objective is to develop a theoretically based, but engineering-oriented, molecular-thermodynamic model which can describe the phase behavior of asphaltene precipitation in petroleum fluids, to provide guidance for petroleum-engineering design and production. In this progress report, particular attention is given to the potential of mean force between asphaltene molecules in a medium of asphaltene-free solvent. This potential of mean force is derived using the principles of colloid science. It depends on the properties of asphaltene and those of the solvent as well as on temperature and pressure. The effect of a solvent on interactions between asphaltenes is taken into account through its density and through its molecular dispersion properties.

  2. Canadian Precipitation Analysis (CaPA): Integration of satellite precipitation data

    NASA Astrophysics Data System (ADS)

    Friesen, B.; Rasmussen, P. F.; Fortin, V.

    2013-12-01

    CaPA (Canadian Precipitation Analysis) is a system developed by Environment Canada to produce gridded real-time precipitation estimates on a sub-daily basis. This is accomplished through the use of statistical interpolation to combine gridded precipitation from Environment Canada's Global Environmental Multiscale model (GEM) with synoptic weather stations. The goal of CaPA is to produce an accurate representation of precipitation, spatially and temporally, benefitting many hydrological applications including the forecasting of floods, agriculture, climatic studies, and use as a resource. In areas across Canada the network density of weather stations can be quite low, limiting the accuracy of any interpolation method. This is especially concerning where the area between stations is large enough to contain entire events, such as convective storms which contribute large amounts of precipitation over small areas. The project investigates the inclusion of satellite data from Precipitation Estimation from Remote Sensing Information using Artificial Neural Networks (PERSIANN) and the Climate Prediction Center morphing (CMORPH) technique into CaPA in an attempt to capture events that would otherwise go unnoticed. Prior to an assimilation into CaPA, a comparison of the satellite products to the Second Generation of Daily Adjusted Precipitation for Canada (APC2) is performed. Measures of correlation and bias ratio show seasonal and spatial trends in performance, warranting some pre-processing of the satellite data before its use. Semi-variogram analysis of station data gives insight into the extent of which a correction can be applied. The focus of pre-processing is on both the adjustment of the magnitudes of the satellite data and the detection of events. The final part of the project is an analysis of the effects on the CaPA output, being a combination of the GEM model, synoptic weather stations and satellite data. The evaluation is a comparison of the change in skill

  3. Making Satellite Precipitation Data Work for the Developing World

    NASA Astrophysics Data System (ADS)

    Gebregiorgis, A. S.; Hossain, F.

    2013-12-01

    The traditional approach to measuring precipitation by placing a probe on the ground will likely never be adequate or affordable in most parts of the world. Fortunately, satellites today provide a continuous global bird's-eye view (above ground) at any given location.However, the usefulness of such precipitation products for hydrological applications depends on their error characteristics and how intelligently we can harness the implications of uncertainty for surface hydrology. Satellite precipitation data is most useful where there exists little to none conventional measurements. As a result, the conventional method of comparing satellite estimate against in-situ records to 'harness' the uncertainty is unrealistic and impractical. As a community tasked with the job of making satellite precipitation 'work' for applications in most parts of the world, there is now a need think outside the box. The manuscript aims to describe a method that will 'truly' work in the developing world. The proposed manuscript aims to provide a broad view summary of our work on making hydrologically merged precipitation data work in the Middle East, Europe, Asia and Mediterranean regions. The aim will be to appeal to a broad range of water managers, climate decision makers and policy and planners in the developing world. The merged precipitation data has already been created for 2002-2010 and will be made freely available to BAMS readers through our ftp site. Globally selected study regions for developing and validating error variance regression model and satellite rainfall products merging scheme

  4. Growing season precipitation in Finland under recent and projected climate

    NASA Astrophysics Data System (ADS)

    Ylhäisi, J. S.; Tietäväinen, , H.; Peltonen-Sainio, P.; Venäläinen, A.; Eklund, J.; Räisänen, J.; Jylhä, K.

    2010-07-01

    The past and projected future precipitation sum in May-September for two areas in Finland, one located in the south-west (SW) and the other in the north-east (NE), is studied using 13 regional climate simulations and three observational datasets. The conditions in the present-day climate for agricultural crop production are far more favourable in the south-western part of the country than the more continental north-eastern Finland. Based on a new high-resolution observational precipitation dataset for Finland (FMI_grid), with a resolution of 10×10 km, the only statistically significant past long-term (1908-2008) precipitation tendencies in the two study regions are positive. Differences between FMI_grid and two other observational datasets during 1961-2000 are rather large in the NE, whereas in the SW the datasets agree better. Observational uncertainties stem from the interpolation and sampling errors. The projected increases in precipitation in the early stage of the growing season would be most favourable for agricultural productivity, but the projected increases in August and September might be harmful. Model projections for the future indicate a statistically significant increase in precipitation for most of the growing season by 2100, but the distribution of precipitation within the growing season is not necessarily the most optimal.

  5. Recombinant protein production technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recombinant protein production is an important technology for antibody production, biochemical activity study, and structural determination during the post-genomic era. Limiting factors in recombinant protein production include low-level protein expression, protein precipitation, and loss of protein...

  6. ANPP-precipitation relationships in multi-year drought experiments in natural ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background/Question/Methods Predicting the effects of a reduction in precipitations on ecosystem productivity confronts an uncertainty: the relationship between aboveground net primary productivity (ANPP) and precipitation differs if the focus is spatial, driven by the climatic mean annual precipi...

  7. Economic impacts of increasing seasonal precipitation variation on cow-calf enterprises

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Economic impacts of predicted increases in precipitation variability on cow-calf enterprises, through influences of precipitation on both forage and cattle productivity, are needed by land managers for risk management strategies. Here we utilize existing forage production and cattle performance data...

  8. Are hourly precipitation extremes increasing faster than daily precipitation extremes?

    NASA Astrophysics Data System (ADS)

    Barbero, Renaud; Fowler, Hayley; Blenkinsop, Stephen; Lenderink, Geert

    2016-04-01

    Extreme precipitation events appear to be increasing with climate change in many regions of the world, including the United States. These extreme events have large societal impacts, as seen during the recent Texas-Oklahoma flooding in May 2015 which caused several billion in damages and left 47 deaths in its path. Better understanding of past changes in the characteristics of extreme rainfall events is thus critical for reliable projections of future changes. Although it has been documented in several studies that daily precipitation extremes are increasing across parts of the contiguous United States, very few studies have looked at hourly extremes. However, this is of primary importance as recent studies on the temperature scaling of extreme precipitation have shown that increases above the Clausius-Clapeyron (~ 7% °C‑1) are possible for hourly precipitation. In this study, we used hourly precipitation data (HPD) from the National Climatic Data Center and extracted more than 1,000 stations across the US with more than 40 years of data spanning the period 1950-2010. As hourly measurements are often associated with a range of issues, the data underwent multiple quality control processes to exclude erroneous data. While no significant changes were found in annual maximum precipitation using both hourly and daily resolution datasets, significant increasing trends in terms of frequency of episodes exceeding present-day 95th percentiles of wet hourly/daily precipitation were observed across a significant portion of the US. The fraction of stations with significant increasing trends falls outside the confidence interval range during all seasons but the summer. While less than 12% of stations exhibit significant trends at the daily scale in the wintertime, more than 45% of stations, mostly clustered in central and Northern United States, show significant increasing trends at the hourly scale. This suggests that short-duration storms have increased faster than daily

  9. Dust particles precipitation in AC/DC electrostatic precipitator

    NASA Astrophysics Data System (ADS)

    Jaworek, A.; Marchewicz, A.; Krupa, A.; Sobczyk, A. T.; Czech, T.; Antes, T.; Śliwiński, Ł.; Kurz, M.; Szudyga, M.; Rożnowski, W.

    2015-10-01

    Submicron and nanoparticles removal from flue or exhaust gases remain still a challenge for engineers. The most effective device used for gas cleaning in power plants or industry is electrostatic precipitator, but its collection efficiency steeply decreases for particles smaller than 1 micron. In this paper, fractional collection efficiency of two-stage electrostatic precipitator comprising of alternating electric field charger and DC supplied parallel-plate collection stage has been investigated. The total number collection efficiency for PM2.5 particles was higher than 95% and mass collection efficiency >99%. Fractional collection efficiency for particles between 300 nm and 1 μm was >95%.

  10. The Global Precipitation Measurement Mission

    NASA Astrophysics Data System (ADS)

    Jackson, Gail

    2014-05-01

    The Global Precipitation Measurement (GPM) mission's Core satellite, scheduled for launch at the end of February 2014, is well designed estimate precipitation from 0.2 to 110 mm/hr and to detect falling snow. Knowing where and how much rain and snow falls globally is vital to understanding how weather and climate impact both our environment and Earth's water and energy cycles, including effects on agriculture, fresh water availability, and responses to natural disasters. The design of the GPM Core Observatory is an advancement of the Tropical Rainfall Measuring Mission (TRMM)'s highly successful rain-sensing package [3]. The cornerstone of the GPM mission is the deployment of a Core Observatory in a unique 65o non-Sun-synchronous orbit to serve as a physics observatory and a calibration reference to improve precipitation measurements by a constellation of 8 or more dedicated and operational, U.S. and international passive microwave sensors. The Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will provide measurements of 3-D precipitation structures and microphysical properties, which are key to achieving a better understanding of precipitation processes and improving retrieval algorithms for passive microwave radiometers. The combined use of DPR and GMI measurements will place greater constraints on possible solutions to radiometer retrievals to improve the accuracy and consistency of precipitation retrievals from all constellation radiometers. Furthermore, since light rain and falling snow account for a significant fraction of precipitation occurrence in middle and high latitudes, the GPM instruments extend the capabilities of the TRMM sensors to detect falling snow, measure light rain, and provide, for the first time, quantitative estimates of microphysical properties of precipitation particles. The GPM Core Observatory was developed and tested at NASA

  11. Eocene precipitation: a global monsoon?

    NASA Astrophysics Data System (ADS)

    Greenwood, D. R.; Huber, M.

    2011-12-01

    The Eocene was the warmest part of the Cenozoic, with warm climates extending across all continents including Antarctica, and extending into the Arctic. Substantive paleobotanical evidence (leaf floras and palynofloras) has demonstrated the existence of broadleaf and coniferous polar forests - a circumpolar rain forest - at both poles. North and South America, Australia, and China in the Eocene were well-forested and humid continents, in contrast to today where 2/3 of these continental areas are arid or semi-arid and lack forests. Each of these regions reflect past climate states - mesothermal moist climates with low thermal seasonality at high latitudes - that have no analog in the modern world. Recent modelling and paleontological proxy data, however, is revealing a high degree of seasonality to precipitation for these continental areas, indicating a monsoon-type precipitation regime may have characterized Eocene 'greenhouse climates'. Paleobotanical proxies offer 2 methods for estimated paleo-precipitation; leaf physiognomy (including both CLAMP and leaf area analysis), and quantitative analysis of nearest living relatives ('NLRs') of macrofloras. Presented here are 1) an updated leaf area analysis calibration with smaller errors of the estimate than previously provided, and 2) analyses of fossil floras from North America, Canada, the Arctic, and Australia. Analysis of the Canadian floras indicate moist climates (MAP >100cm/a) in the early and middle Eocene at middle and high paleolatitudes. Precipitation for western North America at mid-latitudes is also estimated as high, but a seasonally dry interior and south-east is indicated. For Australia, precipitation in the south-east is estimated >120 cm/a, but the macrofloras indicate a drier interior (MAP ~60 cm/a) and seasonal drought, contradicting estimates of ~120 cm/a based on NLR analysis of pollen floras. Recently published data show that north-eastern China in the Eocene had a monsoonal-type seasonality for

  12. A unified approach to asphaltene precipitation: Laboratory measurement and modeling

    SciTech Connect

    MacMillan, D.J.; Tackett, J.E. Jr.; Jessee, M.A.; Monger-McClure, T.G.

    1995-09-01

    A unified approach to evaluation of asphaltene precipitation based on laboratory measurement and modeling is presented. This approach uses an organic deposition cell (ODC) for measuring asphaltene-dropout onset conditions. Asphaltene precipitation was detected by changes in optical fluorescence, electrical conductance, and visual observation. A series of experiments measured the effects of changing pressure,m temperature, and composition on asphaltene precipitation. A fully compositional vapor/liquid/solid (V/L/S) mathematical model completed by analysis by matching the experimental results. The authors then used the model to forecast asphaltene precipitation under a variety of production scenarios, including response to gas-lift operations,and to evaluate the possible location of a tar mat.

  13. Statistical study of precipitating electrons

    NASA Technical Reports Server (NTRS)

    Fontheim, E. G.; Stasiewicz, K.; Chandler, M. O.; Ong, R. S. B.; Hoffman, R. A.

    1981-01-01

    Energy spectra of precipitating electrons are fitted to the sum of three distributions: a power law, a Maxwellian and a Gaussian. This fitting procedure determines seven parameters which characterize the essential features of each spectrum. These characteristic parameters are used to carry out various studies involving precipitating electrons. It is shown that the absence of the power-law population from a particular spectrum is related to the softness of the precipitating primary flux, that the Maxwellian temperature and the Gaussian peak energy have a positive correlation the strength of which varies with local time, that the upward moving Gaussian population has a loss cone distribution, and that the one dimensional velocity distribution parallel to the magnetic field occasionally displays a plateau or a hump on the tail.

  14. Portable liquid collection electrostatic precipitator

    DOEpatents

    Carlson, Duane C.; DeGange, John J.; Halverson, Justin E.

    2005-10-18

    A portable liquid collection electrostatic collection precipitator for analyzing air is provided which is a relatively small, self-contained device. The device has a tubular collection electrode, a reservoir for a liquid, and a pump. The pump pumps the liquid into the collection electrode such that the liquid flows down the exterior of the collection electrode and is recirculated to the reservoir. An air intake is provided such that air to be analyzed flows through an ionization section to ionize analytes in the air, and then flows near the collection electrode where ionized analytes are collected. A portable power source is connected to the air intake and the collection electrode. Ionizable constituents in the air are ionized, attracted to the collection electrode, and precipitated in the liquid. The precipitator may also have an analyzer for the liquid and may have a transceiver allowing remote operation and data collection.

  15. Timber Mountain Precipitation Monitoring Station

    SciTech Connect

    Lyles, Brad; McCurdy, Greg; Chapman, Jenny; Miller, Julianne

    2012-01-01

    A precipitation monitoring station was placed on the west flank of Timber Mountain during the year 2010. It is located in an isolated highland area near the western border of the Nevada National Security Site (NNSS), south of Pahute Mesa. The cost of the equipment, permitting, and installation was provided by the Environmental Monitoring Systems Initiative (EMSI) project. Data collection, analysis, and maintenance of the station during fiscal year 2011 was funded by the U.S. Department of Energy, National Nuclear Security Administration, Nevada Site Office Environmental Restoration, Soils Activity. The station is located near the western headwaters of Forty Mile Wash on the Nevada Test and Training Range (NTTR). Overland flows from precipitation events that occur in the Timber Mountain high elevation area cross several of the contaminated Soils project CAU (Corrective Action Unit) sites located in the Forty Mile Wash watershed. Rain-on-snow events in the early winter and spring around Timber Mountain have contributed to several significant flow events in Forty Mile Wash. The data from the new precipitation gauge at Timber Mountain will provide important information for determining runoff response to precipitation events in this area of the NNSS. Timber Mountain is also a groundwater recharge area, and estimation of recharge from precipitation was important for the EMSI project in determining groundwater flowpaths and designing effective groundwater monitoring for Yucca Mountain. Recharge estimation additionally provides benefit to the Underground Test Area Sub-project analysis of groundwater flow direction and velocity from nuclear test areas on Pahute Mesa. Additionally, this site provides data that has been used during wild fire events and provided a singular monitoring location of the extreme precipitation events during December 2010 (see data section for more details). This letter report provides a summary of the site location, equipment, and data collected in

  16. Measurement and modeling of asphaltene precipitation

    SciTech Connect

    Burke, N.E.; Hobbs, R.E.; Kashou, S.F. )

    1990-11-01

    This paper reports on experimental asphaltene precipitation data on several live-oil/solvent mixtures at reservoir conditions measured to study the effects of temperature, pressure, and composition on precipitate formation and the relationships between critical properties, PVT phase behavior, and precipitate formation. Data generated by the model can be used to identify operating conditions conducive to precipitate formation.

  17. Electron precipitation pattern and substorm morphology

    NASA Technical Reports Server (NTRS)

    Hoffman, R. A.; Burch, J. L.

    1972-01-01

    Patterns of the precipitation of low energy electrons observed by polar satellites were examined as functions of substorm phase. Precipitation boundaries are generally identifiable at the low latitude edge of polar cusp electron precipitation and at the poleward edge of precipitation in the premidnight sector. Both of these boundaries move equatorward when the interplanetary magnetic field turns southward.

  18. Neptunium_Oxide_Precipitation_Kinetics_AJohnsen

    SciTech Connect

    Johnsen, A M; Roberts, K E; Prussin, S G

    2012-06-08

    We evaluate the proposed NpO{sub 2}{sup +}(aq)-NpO{sub 2}(cr) reduction-precipitation system at elevated temperatures to obtain primary information on the effects of temperature, ionic strength, O{sub 2} and CO{sub 2}. Experiments conducted on unfiltered solutions at 10{sup -4} M NpO{sub 2}{sup +}(aq), neutral pH, and 200 C indicated that solution colloids strongly affect precipitation kinetics. Subsequent experiments on filtered solutions at 200, 212, and 225 C showed consistent and distinctive temperature-dependent behavior at reaction times {le} 800 hours. At longer times, the 200 C experiments showed unexpected dissolution of neptunium solids, but experiments at 212 C and 225 C demonstrated quasi steady-state neptunium concentrations of 3 x 10{sup -6} M and 6 x 10{sup -6} M, respectively. Solids from a representative experiment analyzed by X-ray diffraction were consistent with NpO{sub 2}(cr). A 200 C experiment with a NaCl concentration of 0.05 M showed a dramatic increase in the rate of neptunium loss. A 200 C experiment in an argon atmosphere resulted in nearly complete loss of aqueous neptunium. Previously proposed NpO{sub 2}{sup +}(aq)-NpO{sub 2}(cr) reduction-precipitation mechanisms in the literature specified a 1:1 ratio of neptunium loss and H{sup +} production in solution over time. However, all experiments demonstrated ratios of approximately 0.4 to 0.5. Carbonate equilibria can account for only about 40% of this discrepancy, leaving an unexpected deficit in H+ production that suggests that additional chemical processes are occurring.

  19. Declining streamflows reveal nonstationary orographic precipitation enhancement driven by reduced westerly flows

    NASA Astrophysics Data System (ADS)

    Luce, Charles; Abatzoglou, John; Holden, Zachary

    2016-04-01

    Although orographic enhancement of precipitation lends mountains an important role in water resources, they are dramatically undersampled by long-term precipitation gages. This has led to the widespread practice of extrapolating trends in low-elevation precipitation gage networks to high elevations via simple climatological precipitation ratios developed from isohyetal maps. An implicit assumption in such a process is non-stationarity in orographic precipitation enhancement, an assumption that can lead to large errors in trend detection and attribution of climate change effects. We show an example from the Northwestern United States where streamflows from mountain watersheds show substantial declines over the last 60 years, even while long-term precipitation gage networks in the region show no trend. We demonstrate that these observed streamflow declines are driven by previously unexplored differential trends in precipitation. November to March westerly winds are strongly correlated with high-elevation precipitation but weakly correlated with low-elevation precipitation. Decreases in winter westerlies across the region from 1950 to 2012 are hypothesized to have reduced orographic precipitation enhancement, yielding differential trends in precipitation across elevations leading to the apparent paradox. Climate projections show continued weakening meridional pressure gradients and westerly flow across the region under greenhouse forcing, highlighting an additional stressor that is relevant for climate change impacts on water resources. This study also reveals the potential of wind speed data from circulation reanalysis products to better inform historical precipitation reconstructions.

  20. A Physically-Based Multivariate-Regression Approach for Downscaling NEXRAD Precipitation in Mountainous Terrain

    NASA Astrophysics Data System (ADS)

    Guan, H.; Xie, H.; Wilson, J. L.

    2006-05-01

    Precipitation temporal and spatial variability often controls terrestrial hydrologic processes and states. Common remotely-sensed precipitation products have a spatial resolution that is often too coarse to reveal hydrologically important spatial variability. A parsimonious physically-based multivariate-regression algorithm, referred to as multi-level cluster-optimizing ASOADeK regression, is developed for downscaling low-resolution spatial precipitation fields. This algorithm auto-searches precipitation spatial structures (e.g., rain cells), and atmospheric and orographic effects, to estimate precipitation distribution without prior knowledge of the atmospheric setting. The only required input data for the downscaling algorithm are a large-pixel precipitation map and the DEM map of the area of interest. We tested the algorithm on NEXRAD precipitation fields with 4km x 4km large pixels. The algorithm generated 1km x 1km downscaled daily precipitation maps, which we judge successful for the mountainous terrain in terms of precipitation spatial statistics and pair comparisons of pixel values and rain gauges. It produced acceptable downscaled hourly precipitation maps in terms of precipitation spatial statistics, but not in regard of pixel-gauge comparison. The algorithm also successfully retrieves the overall moisture flux direction for the precipitation field. These promising results suggest that the algorithm is worthy of further exploration and development.

  1. Creating synergy between ground and space-based precipitation measurements

    NASA Astrophysics Data System (ADS)

    Gourley, J. J.; Hong, Y.; Petersen, W. A.; Howard, K.; Flamig, Z.; Wen, Y.

    2010-12-01

    As the successor of the Tropical Rainfall Measuring Mission (TRMM) satellite launched in 1997, the multi-national Global Precipitation Measurement (GPM) Mission, to be launched in 2013, will provide next-generation global precipitation estimates from space within a unified framework. On the ground, several countries worldwide are in the throes of expanding their weather radar networks with gap-filling radars and upgrading them to include polarimetric capabilities. While significant improvements in precipitation estimation capabilities have been realized from space- and ground-based platforms separately, little effort has been focused on aligning these communities for synergistic, joint development of algorithms. In this study, we demonstrate the integration of real-time rainfall products from the Tropical Rainfall Measurement Mission (TRMM) into the National Severe Storms Laboratory’s (NSSL) National Mosaic and QPE (NMQ/Q2; http://nmq.ou.edu) system. The NMQ system enables a CONUS-wide comparison of TRMM products to NEXRAD-based Q2 rainfall products. Moreover, NMQ’s ground validation software ingests and quality controls data from all automatic-reporting rain gauge networks throughout the US and provides robust graphical and statistical validation tools, accessible by anyone with internet access. This system will readily incorporate future products from GPM as well as those from the dual-polarization upgrade to the NEXRAD network. While initial efforts are on the intercomparison of rainfall products, we envision this system will ultimately promote the development of precipitation algorithms that capitalize on the strengths of spatiotemporal and error characteristics of space and ground remote-sensing data. An example algorithm is presented where the vertical structure of precipitating systems over complex terrain is more completely resolved using combined information from NMQ and TRMM precipitation radar (PR), leading to more accurate surface rainfall estimates.

  2. Microbially induced and microbially catalysed precipitation: two different carbonate factories

    NASA Astrophysics Data System (ADS)

    Meister, Patrick

    2016-04-01

    The landmark paper by Schlager (2003) has revealed three types of benthic carbonate production referred to as "carbonate factories", operative at different locations at different times in Earth history. The tropical or T-factory comprises the classical platforms and fringing reefs and is dominated by carbonate precipitation by autotrophic calcifying metazoans ("biotically controlled" precipitation). The cool or C-factory is also biotically controlled but via heterotrophic, calcifying metazoans in cold and deep waters at the continental margins. A further type is the mud-mound or M-factory, where carbonate precipitation is supported by microorganisms but not controlled by a specific enzymatic pathway ("biotically induced" precipitation). How exactly the microbes influence precipitation is still poorly understood. Based on recent experimental and field studies, the microbial influence on modern mud mound and microbialite growth includes two fundamentally different processes: (1) Metabolic activity of microbes may increase the saturation state with respect to a particular mineral phase, thereby indirectly driving the precipitation of the mineral phase: microbially induced precipitation. (2) In a situation, where a solution is already supersaturated but precipitation of the mineral is inhibited by a kinetic barrier, microbes may act as a catalyser, i.e. they lower the kinetic barrier: microbially catalysed precipitation. Such a catalytic effect can occur e.g. via secreted polymeric substances or specific chemical groups on the cell surface, at which the minerals nucleate or which facilitate mechanistically the bonding of new ions to the mineral surface. Based on these latest developments in microbialite formation, I propose to extend the scheme of benthic carbonate factories of Schlager et al. (2003) by introducing an additional branch distinguishing microbially induced from microbially catalysed precipitation. Although both mechanisms could be operative in a M

  3. Fusing precipitation for NOAA's AWIPS DSS through a hydro-information system

    NASA Astrophysics Data System (ADS)

    Liang, X.; Wang, S.; Nan, Z.; Adams, T.; Teng, W.; Chiu, L. S.; Liang, Y.

    2008-12-01

    Accurate precipitation estimation is essential to hydrologic modeling for flood and drought forecasts. With advancements in technology, precipitation can now be measured by a range of sensors, including the NOAA/National Weather Service NEXRAD radar network, satellites, and rain gauges. Each measurement platform and the data product(s) associated with it have their own strengths and weaknesses. There are different precipitation products derived from different data sources and from combinations of them. These data products vary in their spatial and temporal resolutions. In this study, we illustrate the integration of our MKF-based (Multiscale Kalman Filter) framework with our hydro-information system to fuse Stage III/Multi- sensor Precipitation Estimator (MPE) hourly NEXRAD precipitation data at approximately 4 by 4 square kilometer resolution with the precipitation data from LDAS (Land Data Assimilation Systems) at 1/8 degree resolution. Two data products from LDAS are investigated. One is the EDAS (NCEP's Eta-based 4-D Data Assimilation System) precipitation product, and the other is the combo precipitation product which is derived from the ?degree CPC (Climate Precipitation Center) daily precipitation data from rain gauges. The combo product is interpolated to 1/8 degree resolution based on the budget bilinear interpolation method. The daily time step of the combo product is disaggregated into hourly data based on either the weight of the hourly Stage II NEXRAD radar or EDAS hourly precipitation or uniformly, if there is no information from either Stage II NEXRAD radar or EDAS hourly precipitation. Our hydro-information system facilitates heterogeneous data retrieval from different data sources into the MKF-based data fusion framework, and then to the hydrological modeling system through an extension of the Hydrological Integrated Data Environment (HIDE) system. Initial results show significant differences in spatial coverage and magnitudes between the original

  4. Current Status of Japanese Global Precipitation Measurement (GPM) Research Project

    NASA Astrophysics Data System (ADS)

    Kachi, Misako; Oki, Riko; Kubota, Takuji; Masaki, Takeshi; Kida, Satoshi; Iguchi, Toshio; Nakamura, Kenji; Takayabu, Yukari N.

    2013-04-01

    The Global Precipitation Measurement (GPM) mission is a mission led by the Japan Aerospace Exploration Agency (JAXA) and the National Aeronautics and Space Administration (NASA) under collaboration with many international partners, who will provide constellation of satellites carrying microwave radiometer instruments. The GPM Core Observatory, which carries the Dual-frequency Precipitation Radar (DPR) developed by JAXA and the National Institute of Information and Communications Technology (NICT), and the GPM Microwave Imager (GMI) developed by NASA. The GPM Core Observatory is scheduled to be launched in early 2014. JAXA also provides the Global Change Observation Mission (GCOM) 1st - Water (GCOM-W1) named "SHIZUKU," as one of constellation satellites. The SHIZUKU satellite was launched in 18 May, 2012 from JAXA's Tanegashima Space Center, and public data release of the Advanced Microwave Scanning Radiometer 2 (AMSR2) on board the SHIZUKU satellite was planned that Level 1 products in January 2013, and Level 2 products including precipitation in May 2013. The Japanese GPM research project conducts scientific activities on algorithm development, ground validation, application research including production of research products. In addition, we promote collaboration studies in Japan and Asian countries, and public relations activities to extend potential users of satellite precipitation products. In pre-launch phase, most of our activities are focused on the algorithm development and the ground validation related to the algorithm development. As the GPM standard products, JAXA develops the DPR Level 1 algorithm, and the NASA-JAXA Joint Algorithm Team develops the DPR Level 2 and the DPR-GMI combined Level2 algorithms. JAXA also develops the Global Rainfall Map product as national product to distribute hourly and 0.1-degree horizontal resolution rainfall map. All standard algorithms including Japan-US joint algorithm will be reviewed by the Japan-US Joint

  5. Acid Precipitation: Causes and Consequences.

    ERIC Educational Resources Information Center

    Babich, Harvey; And Others

    1980-01-01

    This article is the first of three articles in a series on the acid rain problem in recent years. Discussed are the causes of acid precipitation and its consequences for the abiotic and biotic components of the terrestrial and aquatic ecosystems, and for man-made materials. (Author/SA)

  6. SULFIDE PRECIPITATION OF HEAVY METALS

    EPA Science Inventory

    The research program was initiated with the objective of evaluating a new process, the sulfide precipitation of heavy metals from industrial wastewaters. The process was expected to effect a more complete removal of heavy metals than conventional lime processing because of the mu...

  7. Extreme precipitation: Increases all round

    NASA Astrophysics Data System (ADS)

    Ingram, William

    2016-05-01

    Globally, extreme rainfall is expected to increase with warming, but regional changes over land have been less certain. Now research shows that this intense precipitation has increased across both the wetter and the drier parts of the continents, and will continue to do so as global warming continues.

  8. Waste and Simulant Precipitation Issues

    SciTech Connect

    Steele, W.V.

    2000-11-29

    As Savannah River Site (SRS) personnel have studied methods of preparing high-level waste for vitrification in the Defense Waste Processing Facility (DWPF), questions have arisen with regard to the formation of insoluble waste precipitates at inopportune times. One option for decontamination of the SRS waste streams employs the use of an engineered form of crystalline silicotitanate (CST). Testing of the process during FY 1999 identified problems associated with the formation of precipitates during cesium sorption tests using CST. These precipitates may, under some circumstances, obstruct the pores of the CST particles and, hence, interfere with the sorption process. In addition, earlier results from the DWPF recycle stream compatibility testing have shown that leaching occurs from the CST when it is stored at 80 C in a high-pH environment. Evidence was established that some level of components of the CST, such as silica, was leached from the CST. This report describes the results of equilibrium modeling and precipitation studies associated with the overall stability of the waste streams, CST component leaching, and the presence of minor components in the waste streams.

  9. Classroom Exercises Utilizing Precipitation Data.

    ERIC Educational Resources Information Center

    Kohler, Fred

    Precipitation data for Macomb (Illinois) for the period 1912-1981 were the bases for developing classroom exercises that offered college students experience in collecting such data. After students collected the data, they reduced them to manageable proportions, and then examined average long-term relations which may have emerged among yearly,…

  10. Conditional Generation of Monthly Precipitation

    NASA Astrophysics Data System (ADS)

    Kim, U.; Kaluarachchi, J. J.

    2006-12-01

    Monthly precipitation models can be used in basin-wide modeling to develop long-term strategies for water resources planning and management and to estimate the change of water yield due to climate change. Such precipitation models are especially important for effective management of river basins in developing countries such as the upper Blue Nile River basin of Ethiopia where the water resource utilization is limited. Many studies have been previously performed to preserve historical temporal and spatial structures when generating precipitation series. The main focus of those studies was to preserve the historical statistics. Other important factors to be considered are transition and spatial correlations. A few recent studies attempted to preserve transition as well as the statistics of historical record. These studies provided satisfactory results while showing the difficulty and complexity of computations in their methods. The conditional generation method (CGM) that can preserve both historical temporal and spatial structures is presented in this study. Because the CGM is driven from the historical conditional probabilities occurring given amounts of precipitation between two successive months or two stations, it is computationally simple and reliable, i.e., parameterization, inverse matrix, or optimum band width is not required. The CGM was applied to reproducing the precipitation pattern of the upper Blue Nile River basin in Ethiopia using monthly precipitation data of 10 stations to demonstrate its applicability. Comparing to the method of inverse transformation of cumulative distribution functions of the gamma distribution and nonparametric kernel estimator with variable band width selected from the goodness-of-fit tests, the CGM showed improved performance, especially in representing the transition characteristics. The CGM also generated the historical spatial correlations between the stations with acceptable accuracy. The results suggested that the CGM

  11. Using satellite precipitation data for hydrological modeling

    NASA Astrophysics Data System (ADS)

    Commandeur, Tom

    2013-04-01

    The growing demand for precipitation data covering larger areas of the globe as lead to the need of innovative approaches to the operationalization of data streams. One possible classical solution is combining and calibrating various ground radar stations, however the availability and cost of these data streams work against its use for global coverage . The alternative is to use Earth Observation data from satellites. There is a wide range of weather data available from polar orbital satellites with sensors for measurements. The biggest advantage is that the spatial coverage is wide, however the temporal resolution for the covered area is more limited. To take advantage of the better of two worlds, geostationary satellites can be used to give the temporal resolution for the same covered area at a regular interval. EUMETSAT's Multi-Sensor Precipitation Estimate (MPE) is based on a classical blending algorithm. This algorithm combines SSM/I instruments on DMSP satellites with the 10.8 micron IR window channel on Meteosat satellites. The result is precipitation estimates with a spatial coverage on most of Europe and Africa and a temporal resolution of 15 minutes. To be able to receive the latest MPE data from EUMETSAT in near real-time a reception station for EUMETCast needs to be set up. With this reception station all data received from Meteosat satellites can be acquired as well as third-party products. The data is post-processed by Meteorological Products Extraction Facility of EUMETSAT, mostly for correction of image distortion and quality assurance. Due to this the data is received with a delay of about 15 minutes. MPE data is stored, by default, in Geostationary Satellite View projection and needs to be transformed into a usable projection system. Projections are translated into WGS84 after which they can be interpolated onto a regular spaced latitude/longitude grid. This paper handles the description of the process of transformation and interpolation

  12. Spatio-temporal patterns of precipitation in Serbia

    NASA Astrophysics Data System (ADS)

    Gocic, Milan; Trajkovic, Slavisa

    2014-08-01

    The monthly precipitation data from 29 synoptic stations for the period 1946-2012 were analyzed using a number of different multivariate statistical analysis methods to investigate the spatial variability and temporal patterns of precipitation across Serbia. R-mode principal component analysis was used to study the spatial variability of the precipitation. Three distinct sub-regions were identified by applying the agglomerative hierarchical cluster analysis to the two component scores: C1 includes the north and the northeast part of Serbia, while C2 includes the western part of Central Serbia and southwestern part of Serbia and C3 includes central, east, south and southeast part of Serbia. The analysis of the identified sub-regions indicated that the monthly and seasonal precipitation in sub-region C2 had the values above average, while C1 and C3 had the precipitation values under average. The analysis of the linear trend of the mean annual precipitation showed an increasing trend for the stations located in Serbia and three sub-regions. From the result of this analysis, one can plan land use, water resources and agricultural production in the region.

  13. Application of an Object-Oriented Connectivity Algorithm to Remotely Sensed Precipitation Data

    NASA Astrophysics Data System (ADS)

    Sellars, S.; Nguyen, P.; Chu, W.; Gao, X.; Sorooshian, S.

    2012-12-01

    A new object-oriented precipitation database was developed. This dataset treats each precipitation event as four-dimensional objects and describes the spatial-temporal characteristics of the precipitation objects. The purpose of this dataset is to perform precipitation observational product comparison, observation/model verification, climate studies and engineering applications. Engineering applications would include extreme event(s) emulation and simulation for infrastructure planning and impact assessment. The data used for populating the object-oriented data set was the hourly, .25 Degree resolutions Precipitation Estimation using Remote Sensing Information and the Artificial Neural Network (PERSIANN) product, which covers 60N to 60S from March 1st, 2000 to September 30th, 2009. This product was bias corrected to match monthly precipitation values from the Global Precipitation Climate Project (GPCP). PERSIANN uses neural network techniques to estimate precipitation rates from geostationary infrared imagery, while calibrating it according to microwave imagery. The neural network is calibrated using both infrared and passive microwave data from the different available satellites. Instead of developing a traditional data set, which organizes precipitation at each data point within a defined grid, this poster will demonstrate the application of a connectivity algorithm developed by Dr. Wei Chu (CHRS Researcher), which organizes high resolution (.25 degree) near global precipitation data into four-dimensional objects (latitude, longitude, time, and intensity) and stores the information in a database. This algorithm is designed to ensure that all pixels of precipitation estimates are connected in both space and time (connected pixels), allowing for the feature to be analyzed as a four-dimensional object. Two main criteria are set before the connectivity algorithm is applied to the PERSIANN dataset; 1st) all precipitation pixels must have at least 1mm/hr, and 2nd) the

  14. Dissolved Organic Carbon In Precipitation At A Coastal Rural Site

    NASA Astrophysics Data System (ADS)

    Liptzin, D.; Daley, M.; Sive, B. C.; Talbot, R. W.; McDowell, W. H.

    2013-12-01

    Dissolved organic carbon (DOC) is a ubiquitous component of precipitation. This DOC is a complex mixture of compounds from biogenic and anthropogenic sources. The amount and chemistry of the DOC in precipitation has been studied for a variety of reasons: as a source of acidity, as a source of C to marine and terrestrial ecosystems, or to track the fate of individual compounds or pollutants. In most cases, past studies have focused on particular compounds or a limited number of precipitation events. Very little is known about the temporal trends in DOC or the relationship between DOC and other constituents of precipitation. We collected precipitation events for more than five years at a rural coastal site in New Hampshire. We evaluated the seasonal patterns and compared the DOC concentrations to other typical measures of the wet atmospheric deposition (ammonium, nitrate, sulfate, and chloride). In addition, we compared the DOC in precipitation to the concentrations of various organic constituents of the atmosphere. The volume weighted mean C concentration was 0.75 mg C/L with concentrations in the summer significantly higher than in the other three seasons. The DOC concentration was most strongly associated with ammonium concentrations (r=0.81), but was also significantly related to nitrate (r=0.50) and sulfate (r=0.63) concentrations. There was no significant association between DOC and chloride concentrations. Preliminary regression tree analysis suggests that the DOC concentration in precipitation was best predicted by the atmospheric concentration of methyl vinyl ketone, an oxidation product of isoprene. These results suggest that both terrestrial biogenic and anthropogenic sources may be important precursors to the C removed from the atmosphere during precipitation events.

  15. The Use of Multi-Sensor Quantitative Precipitation Estimates for Deriving Extreme Precipitation Frequencies with Application in Louisiana

    NASA Astrophysics Data System (ADS)

    El-Dardiry, Hisham Abd El-Kareem

    The Radar-based Quantitative Precipitation Estimates (QPE) is one of the NEXRAD products that are available in a high temporal and spatial resolution compared with gauges. Radar-based QPEs have been widely used in many hydrological and meteorological applications; however, a few studies have focused on using radar QPE products in deriving of Precipitation Frequency Estimates (PFE). Accurate and regionally specific information on PFE is critically needed for various water resources engineering planning and design purposes. This study focused first on examining the data quality of two main radar products, the near real-time Stage IV QPE product, and the post real-time RFC/MPE product. Assessment of the Stage IV product showed some alarming data artifacts that contaminate the identification of rainfall maxima. Based on the inter-comparison analysis of the two products, Stage IV and RFC/MPE, the latter was selected for the frequency analysis carried out throughout the study. The precipitation frequency analysis approach used in this study is based on fitting Generalized Extreme Value (GEV) distribution as a statistical model for the hydrologic extreme rainfall data that based on Annual Maximum Series (AMS) extracted from 11 years (2002-2012) over a domain covering Louisiana. The parameters of the GEV model are estimated using method of linear moments (L-moments). Two different approaches are suggested for estimating the precipitation frequencies; Pixel-Based approach, in which PFEs are estimated at each individual pixel and Region-Based approach in which a synthetic sample is generated at each pixel by using observations from surrounding pixels. The region-based technique outperforms the pixel based estimation when compared with results obtained by NOAA Atlas 14; however, the availability of only short record of observations and the underestimation of radar QPE for some extremes causes considerable reduction in precipitation frequencies in pixel-based and region

  16. Global Precipitation Analyses at Monthly to 3-HR Time Scales

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Huffman, George; Curtis, Scott; Bolvin, David; Nelkin, Eric

    2002-01-01

    Global precipitation analysis covering the last few decades and the impact of the new TRMM precipitation observations are discussed. The 20+ year, monthly, globally complete precipitation analysis of the World Climate Research Program's (WCRP/GEWEX) Global Precipitation Climatology Project (GPCP) is used to explore global and regional variations and trends and is compared to the much shorter TRMM(Tropica1 Rainfall Measuring Mission) tropical data set. A trend pattern that is a combination of both El Nino and La Nina precipitation features is evident in the 20-year data set. This pattern is related to an increase with time in the number of combined months of El Nino and La Nina during the 20 year period. Monthly anomalies of precipitation are related to ENSO variations with clear signals extending into middle and high latitudes of both hemispheres. The GPCP daily, 1deg latitude-longitude analysis, which is available from January 1997 to the present is described and the evolution of precipitation patterns on this time scale related to El Nino and La Nina is described. Finally, a TRMM-based 3-hr analysis is described that uses TRMM to calibrate polar-orbit microwave observations from SSM/I and geosynchronous IR observations and merges the various calibrated observations into a final, 3-hr resolution map. This TRMM standard product will soon be available for the entire TRMM period (January 1998- present). A real-time version of this merged product is being produced and is available at 0.25deg latitude-longitude resolution over the latitude range from 50degN-50degS. Images from this data set can be seen at the U.S. TRMM web site (trmm.gsfc.nasa.gov). Examples will be shown, including its use in monitoring flood conditions and relating weather-scale events to climate variations.

  17. Evaluation of NWP Precipitation Forecasts for Global Flood Warning

    NASA Astrophysics Data System (ADS)

    Tian, Y.; Adler, R. F.; Peters-Lidard, C. D.

    2008-12-01

    Precipitation forecasts from numerical weather prediction (NWP) models can potentially improve our ability for global flood and landslide warning. In this study, the skills and errors of three NWP precipitation forecast products were analyzed. These forecast products include GEOS5, GDAS and ECMWF, with lead time ranging from 12 hours to 5 days. They were evaluated against the satellite-based, gauge-corrected precipitation estimates, TMPA 3B42, over the land surface as well as the globe. To gain a better perspective, we also evaluated several other satellite-based precipitation products, including GPCP, TMPA 3B42RT, CMORPH and PERSIANN, against TMPA 3B42. Our analysis shows the three NWP forecasts tend to systematically over-estimate global precipitation by approximately 50%. This positive bias does not change much with lead time. In contrast, the satellite-based estimates (GPCP, TMPA, 3B42RT, CMORPH and PERSIANN) have biases mostly less than 20%. In addition, the RMS errors increase with the lead time in NWP forecasts, and in particular for GEOS5, the most increase in RMS errors takes place when the lead time goes from 1 day to 2 days. The RMS errors in the NWP products are also about twice as much as those of the satellite-based products. Further analysis indicates false alarms dominate the errors in the NWP forecasts. Among the NWP products, GEOS5 has slightly better performance than the other two. The implication of these error characteristics on global flood and landslide warning will be discussed.

  18. Fingering dynamics driven by a precipitation reaction: Nonlinear simulations

    NASA Astrophysics Data System (ADS)

    Shukla, Priyanka; De Wit, A.

    2016-02-01

    A fingering instability can develop at the interface between two fluids when the more mobile fluid is injected into the less-mobile one. For example, viscous fingering appears when a less viscous (i.e., more mobile) fluid displaces a more viscous (and hence less mobile) one in a porous medium. Fingering can also be due to a local change in mobility arising when a precipitation reaction locally decreases the permeability. We numerically analyze the properties of the related precipitation fingering patterns occurring when an A +B →C chemical reaction takes place, where A and B are reactants in solution and C is a solid product. We show that, similarly to reactive viscous fingering patterns, the precipitation fingering structures differ depending on whether A invades B or vice versa. This asymmetry can be related to underlying asymmetric concentration profiles developing when diffusion coefficients or initial concentrations of the reactants differ. In contrast to reactive viscous fingering, however, precipitation fingering patterns appear at shorter time scales than viscous fingers because the solid product C has a diffusivity tending to zero which destabilizes the displacement. Moreover, contrary to reactive viscous fingering, the system is more unstable with regard to precipitation fingering when the high-concentrated solution is injected into the low-concentrated one or when the faster diffusing reactant displaces the slower diffusing one.

  19. Stoichiometric hydroxyapatite obtained by precipitation and sol gel processes

    NASA Astrophysics Data System (ADS)

    Vazquez, C. G.; Barba, C. P.; Munguia, N.

    2005-06-01

    Three methods for obtaining hydroxiapatite (HA) are described. HA is a very interesting ceramic because of its many medical applications. The first two precipitation methods start from calcium and phosphorous compounds, whereas the third method is a sol-gel process that uses alcoxides. The products were characterized and compared. The observed differences are important for practical applications.

  20. Residue management to improve precipitation storage and water use efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Successful dryland crop production in semiarid environments is dependent upon efficient storage of precipitation and use of stored soil water supplies. The objectives of this presentation are to: 1. Summarize information regarding the effects of time of year; environmental parameters; residue orient...

  1. CONCENTRATION OF Pu USING AN IODATE PRECIPITATE

    DOEpatents

    Fries, B.A.

    1960-02-23

    A method is given for separating plutonium from lanthanum in a lanthanum fluoride carrier precipitation process for the recovery of plutonium values from an aqueous solution. The carrier precipitation process includes the steps of forming a lanthanum fluoride precipi- . tate, thereby carrying plutonium out of solution, metathesizing the fluoride precipitate to a hydroxide precipitate, and then dissolving the hydroxide precipitate in nitric acid. In accordance with the invention, the nitric acid solution, which contains plutonium and lanthanum, is made 0.05 to 0.15 molar in potassium iodate. thereby precipitating plutonium as plutonous iodate and the plutonous iodate is separated from the lanthanum- containing supernatant solution.

  2. Global Precipitation Measurement (GPM) Mission: Overview and Status

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2012-01-01

    The Global Precipitation Measurement (GPM) Mission is an international satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. NASA and JAXA will deploy a Core Observatory in 2014 to serve as a reference satellite to unify precipitation measurements from the constellation of sensors. The GPM Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will be the first dual-frequency radar in space to provide not only measurements of 3-D precipitation structures but also quantitative information on microphysical properties of precipitating particles. The DPR and GMI measurements will together provide a database that relates vertical hydrometeor profiles to multi-frequency microwave radiances over a variety of environmental conditions across the globe. This combined database will be used as a common transfer standard for improving the accuracy and consistency of precipitation retrievals from all constellation radiometers. For global coverage, GPM relies on existing satellite programs and new mission opportunities from a consortium of partners through bilateral agreements with either NASA or JAXA. Each constellation member may have its unique scientific or operational objectives but contributes microwave observations to GPM for the generation and dissemination of unified global precipitation data products. In addition to the DPR and GMI on the Core Observatory, the baseline GPM constellation consists of the following sensors: (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer-2 (AMSR-2) on the GCOM-W1 satellite of JAXA, (3) the Multi-Frequency Microwave Scanning Radiometer (MADRAS) and the multi-channel microwave humidity sounder

  3. High-resolution spatiotemporal distribution of precipitation in Iran: a comparative study with three global-precipitation datasets

    NASA Astrophysics Data System (ADS)

    Khalili, Ali; Rahimi, Jaber

    2014-10-01

    High-resolution precipitation datasets are used for numerous applications. However, depending on the procedures for obtaining these products, such as number of observations, quality checking, error-correction procedures, and interpolation techniques, they include many uncertainties. Therefore, the accuracy of these products needs to be evaluated over different regions. In this study, the Iranian National Dataset (INDS), a new 1 × 1 km precipitation dataset based on precipitation data of 1,441 quality-controlled stations for the climatic period from 1961 to 2005, was constructed using the digital elevation model, correlation method, and Kriging interpolation procedure. Iran's annual precipitation values at grids and stations were extracted from Climatic Research Unit (CRU) CL 2.0, CRU TS 3.10.01, and WorldClim datasets, and differences between corresponding values in each of the three datasets and INDS were calculated and analyzed. The coefficient of determination ( R 2) between the national network stations' data and the CRU CL 2.0, CRU TS 3.10.01, and WorldClim datasets were 0.50, 0.13, and 0.62, respectively. Moreover, R 2 values between the grids of each dataset and INDS were 0.51, 0.40, and 0.60, respectively. To determine the global datasets' efficiency for displaying temporal patterns of precipitation, the monthly values gathered from them at 11 stations (as representative of Iran's various precipitation regimes) were compared with the real values at these stations. The results showed that in term of temporal patterns, the concurrences among the three global datasets and the INDS was more acceptable, especially in the case of CRU CL 2.0. In general, it is concluded that the global datasets could be deployed for the primary assessment of the annual precipitation distribution; however, for more precise studies, use of local data is highly recommended.

  4. Acid precipitation; an annotated bibliography

    USGS Publications Warehouse

    Wiltshire, Denise A.; Evans, Margaret L.

    1984-01-01

    This collection of 1660 bibliographies references on the causes and environmental effects of acidic atmospheric deposition was compiled from computerized literature searches of earth-science and chemistry data bases. Categories of information are (1) atmospheric chemistry (gases and aerosols), (2) precipitation chemistry, (3) transport and deposition (wet and dry), (4) aquatic environments (biological and hydrological), (5) terrestrial environments, (6) effects on materials and structures, (7) air and precipitation monitoring and data collection, and (8) modeling studies. References date from the late 1800 's through December 1981. The bibliography includes short summaries of most documents. Omitted are unpublished manuscripts, publications in press, master 's theses and doctoral dissertations, newspaper articles, and book reviews. Coauthors and subject indexes are included. (USGS)

  5. Protein recovery from surfactant precipitation.

    PubMed

    Cheng, Shu Ian; Stuckey, David C

    2011-01-01

    The recovery of lysozyme from an aqueous solution containing precipitated lysozyme-AOT complexes formed by the direct addition of sodium bis-(2-ethylhexyl) sulfosuccinate (AOT) to a lysozyme solution was studied using both solvents, and a counterionic surfactant. Ethanol,methanol and solvent mixtures dissolved the surfactant precipitate and recovered lysozyme as a solid. Recovery efficiency and protein stability varied with the type of solvent used. An entirely different method of recovery was also evaluated using a counterionic surfactant: tri-octylmethylammonium chloride (TOMAC) which bound to AOT releasing lysozyme into solution.Complete recovery (100%) of lysozyme was achieved at a molar ratio of 2:1(TOMAC:AOT), and the original protein activity was maintained in the final aqueous phase.The recovered lysozyme retained its secondary structure as observed in circular dichroism(CD) spectra. Specific activity studies show that counterionic surfactant extraction does not alter the biological activity of the enzyme. PMID:22235487

  6. Assimilation of radar quantitative precipitation estimations in the Canadian Precipitation Analysis (CaPA)

    NASA Astrophysics Data System (ADS)

    Fortin, Vincent; Roy, Guy; Donaldson, Norman; Mahidjiba, Ahmed

    2015-12-01

    The Canadian Precipitation Analysis (CaPA) is a data analysis system used operationally at the Canadian Meteorological Center (CMC) since April 2011 to produce gridded 6-h and 24-h precipitation accumulations in near real-time on a regular grid covering all of North America. The current resolution of the product is 10-km. Due to the low density of the observational network in most of Canada, the system relies on a background field provided by the Regional Deterministic Prediction System (RDPS) of Environment Canada, which is a short-term weather forecasting system for North America. For this reason, the North American configuration of CaPA is known as the Regional Deterministic Precipitation Analysis (RDPA). Early in the development of the CaPA system, weather radar reflectivity was identified as a very promising additional data source for the precipitation analysis, but necessary quality control procedures and bias-correction algorithms were lacking for the radar data. After three years of development and testing, a new version of CaPA-RDPA system was implemented in November 2014 at CMC. This version is able to assimilate radar quantitative precipitation estimates (QPEs) from all 31 operational Canadian weather radars. The radar QPE is used as an observation source and not as a background field, and is subject to a strict quality control procedure, like any other observation source. The November 2014 upgrade to CaPA-RDPA was implemented at the same time as an upgrade to the RDPS system, which brought minor changes to the skill and bias of CaPA-RDPA. This paper uses the frequency bias indicator (FBI), the equitable threat score (ETS) and the departure from the partial mean (DPM) in order to assess the improvements to CaPA-RDPA brought by the assimilation of radar QPE. Verification focuses on the 6-h accumulations, and is done against a network of 65 synoptic stations (approximately two stations per radar) that were withheld from the station data assimilated by Ca

  7. The Global Precipitation Climatology Centre (GPCC) - in situ observation based precipitation climatology on regional and global scale

    NASA Astrophysics Data System (ADS)

    Fuchs, T.; Schneider, U.; Rudolf, B.

    2009-04-01

    The Global Precipitation Climatology Centre (GPCC, http://gpcc.dwd.de) provides global monthly precipitation analyses for monitoring and research of the earth's climate. The centre is a German contribution to the World Climate Research Programme (WCRP), to the Global Climate Observing System (GCOS), and to the Global Earth Observation System of Systems (GEOSS). It contributes to water resources assessments, flood and drought monitoring, climate variability and trend analyses. GPCC published in year 2008 a new global precipitation climatology as well as a reanalysis of its full data base for all months of the period 1901-2007. The GPCC data base comprises monthly precipitation totals from more than 70 000 different stations in the world. It produces gridded data sets of monthly precipitation on the earth's land surface derived from raingauge based observation data. Intensive quality control of observation data and station metadata ensures a high analysis quality. The different GPCC products are adjusted to different user needs. It routinely produces 2 near real-time precipitation monitoring products. Its 2 non real-time products are updated at irregular time intervals after significant updates of its observation station database. All GPCC products can be visualised and accessed free of charge via Internet from http://gpcc.dwd.de. The GPCC First Guess Product of the monthly precipitation anomaly is based on synoptic weather reports (SYNOP) from about 6,300 stations worldwide received near real-time via the WMO Global Telecommunication System (GTS). The product is available within 5 days after end of an observation month. Main application purpose is near real-time drought monitoring. The product uses since mid 2008 the new GPCC monthly precipitation climatology as analysis background. Spatial product resolution: 1.0° and 2.5°. The GPCC Monitoring Product of monthly precipitation is based on SYNOP and monthly CLIMAT reports received near real-time via GTS from about

  8. Hydrologic evaluation of satellite and reanalysis precipitation datasets over a mid-latitude basin

    NASA Astrophysics Data System (ADS)

    Seyyedi, Hojjat; Anagnostou, Emmanouil N.; Beighley, Edward; McCollum, Jeffrey

    2015-10-01

    Using precipitation data from satellite or global reanalysis products to force hydrologic models exhibits complex rainfall error and resolution effects in the simulation of streamflows. This study assesses the error propagation of two global (or near-global) precipitation datasets in terms of flood modeling for a range of basin scales (300-70,000 km2) focusing on multi-year (2002-2011) simulations over a mid-latitude basin (Susquehanna River Basin) in the Northeastern United States. These datasets are the TRMM Multi-satellite Precipitation Analysis 3B42V7 (TRMM3B42V7) research product and the Global Land Data Assimilation (GLDAS) reanalysis system precipitation dataset, which represent 3-hourly rainfall time series at 25-km and hourly time series at 100-km spatial grid resolutions, respectively. The precipitation products, aggregated to a common 3-hourly time resolution, are used to force a distributed hydrologic model (Hillslope River Routing - HRR) for moderate and heavy precipitation events over the basin. The NCEP multi-sensor precipitation analysis (Stage IV) is used as the reference rainfall field for the evaluation of the precipitation and hydrologic simulation errors. Results show that the satellite product exhibits significantly better error statistics compared to the GLDAS. Particularly for the simulated streamflow, GLDAS is shown to have up to 7 (3) times higher mean relative error compared to the corresponding TRMM3B42V7 error metric for moderate (extreme) streamflow values. This significant divergence in the runoff simulation error statistics is attributed to differences between the two precipitation products in terms of the propagation of their error properties from precipitation to simulated streamflow. Significant improvement of the statistical scores (up to 50%) with increasing basin size is shown for the satellite product; this basin scale effect is marginal for the GLDAS product.

  9. Microwave radiative transfer studies of precipitation

    NASA Technical Reports Server (NTRS)

    Bringi, V. N.; Vivekanandan, J.; Turk, F. Joseph

    1993-01-01

    Since the deployment of the DMSP SSM/I microwave imagers in 1987, increased utilization of passive microwave radiometry throughout the 10 - 100 GHz spectrum has occurred for measurement of atmospheric constituents and terrestrial surfaces. Our efforts have focused on observations and analysis of the microwave radiative transfer behavior of precipitating clouds. We have focused particular attention on combining both aircraft and SSM/I radiometer imagery with ground-based multiparameter radar observations. As part of this and the past NASA contract, we have developed a multi-stream, polarized radiative transfer model which incorporates scattering. The model has the capability to be initialized with cloud model output or multiparameter radar products. This model provides the necessary 'link' between the passive microwave radiometer and active microwave radar observations. This unique arrangement has allowed the brightness temperatures (TB) to be compared against quantities such as rainfall, liquid/ice water paths, and the vertical structure of the cloud. Quantification of the amounts of ice and water in precipitating clouds is required for understanding of the global energy balance.

  10. Predictibility in Nowcasting of Precipitation

    NASA Astrophysics Data System (ADS)

    Zawadzki, I.; Sourcel, M.; Berenguer, M.

    2009-05-01

    Present short term precipitation forecasting is based on two methods: Lagrangian persistence (nowcasting) and numerical weather prediction (NWP). An improvement over these methods is obtained by the combination of the two. The obvious shortcoming of nowcasting is its severe limitation in capturing new development or dissipation of precipitation. NWP has the ability to predict both but very imprecisely. An attempt to correct model errors by post-processing leads to some improvement in the skill of NWP, but the improvement, although significative, is not very impressive. The goal of our effort is to take a step back and to describe, in a quantitative manner, a) the nature of the uncertainties affecting Lagrangian persistence and NWP forecasts, as well as to determineb) the physical causes of the uncertainties. We quantify the uncertainties in short term forecasting due to limitation of nowcasting algorithms and NWP to capture correctly some of the physical phenomena that determine the predictability of precipitation. The first factor considered is the diurnal cycle that appears as the one physically determined factors that limit the precision of short term prediction. We study the cycle in radar mosaics over US and compare this to nowcasts and model outputs. The seasonal and geographical dependence of the diurnal cycle is quantitatively evaluated.

  11. Status of the Japanese Global Precipitation Measurement (GPM) Research Project

    NASA Astrophysics Data System (ADS)

    Kachi, Misako; Kubota, Takuji; Masaki, Takeshi; Kaneko, Yuki; Oki, Riko; Iguchi, Toshio; Nakamura, Kenji; Takayabu, Yukari N.

    2014-05-01

    The Global Precipitation Measurement (GPM) mission is a mission led by the Japan Aerospace Exploration Agency (JAXA) and the National Aeronautics and Space Administration (NASA) under collaboration with many international partners, who will provide constellation of satellites carrying microwave radiometer instruments. The GPM Core Observatory, which carries the Dual-frequency Precipitation Radar (DPR) developed by JAXA and the National Institute of Information and Communications Technology (NICT), and the GPM Microwave Imager (GMI) developed by NASA. JAXA also provides the Global Change Observation Mission (GCOM) 1st - Water (GCOM-W1) named "SHIZUKU," as one of constellation satellites. The SHIZUKU satellite was launched on May 18, 2012, and all products, including the precipitation product, have been available to general users since May 2013. The Japanese GPM research project conducts scientific activities on algorithm development, ground validation, application research including production of research products. In addition to those activities, we promote collaboration studies in Japan and Asian countries, and seek potential users of satellite precipitation products. JAXA develops the DPR Level 1 algorithm, and the NASA-JAXA Joint Algorithm Team develops the DPR Level 2 and DPR-GMI combined Level2 algorithms. JAXA also develops the Global Rainfall Map algorithm, which is anew version of the Global Satellite Mapping of Precipitation (GSMaP,) as national product to distribute hourly and 0.1-degree horizontal resolution rainfall map. In the GPM era, the GSMaP algorithm will be improved by refining rainfall retrievals over land, considered the orographic rainfall effects, added the rain gauge corrected rainfall product. In the future, information from the Dual-frequency Precipitation Radar (DPR) will be compiled as a database to improve the retrieval accuracy of weak rainfall in mid-to-high latitudes. The GPM Core Observatory is scheduled to be launched from the JAXA

  12. An Electrostatic Precipitator System for the Martian Environment

    NASA Technical Reports Server (NTRS)

    Calle, C. I.; Mackey, P. J.; Hogue, M. D.; Johansen, M. R.; Phillips, J. R., III; Clements, J. S.

    2012-01-01

    Human exploration missions to Mars will require the development of technologies for the utilization of the planet's own resources for the production of commodities. However, the Martian atmosphere contains large amounts of dust. The extraction of commodities from this atmosphere requires prior removal of this dust. We report on our development of an electrostatic precipitator able to collect Martian simulated dust particles in atmospheric conditions approaching those of Mars. Extensive experiments with an initial prototype in a simulated Martian atmosphere showed efficiencies of 99%. The design of a second prototype with aerosolized Martian simulated dust in a flow-through is described. Keywords: Space applications, electrostatic precipitator, particle control, particle charging

  13. Prototype of NASA's Global Precipitation Measurement Mission Ground Validation System

    NASA Technical Reports Server (NTRS)

    Schwaller, M. R.; Morris, K. R.; Petersen, W. A.

    2007-01-01

    NASA is developing a Ground Validation System (GVS) as one of its contributions to the Global Precipitation Mission (GPM). The GPM GVS provides an independent means for evaluation, diagnosis, and ultimately improvement of GPM spaceborne measurements and precipitation products. NASA's GPM GVS consists of three elements: field campaigns/physical validation, direct network validation, and modeling and simulation. The GVS prototype of direct network validation compares Tropical Rainfall Measuring Mission (TRMM) satellite-borne radar data to similar measurements from the U.S. national network of operational weather radars. A prototype field campaign has also been conducted; modeling and simulation prototypes are under consideration.

  14. Electron precipitation patterns and substorm morphology.

    NASA Technical Reports Server (NTRS)

    Hoffman, R. A.; Burch, J. L.

    1973-01-01

    Statistical analysis of data from the auroral particles experiment aboard OGO 4, performed in a statistical framework interpretable in terms of magnetospheric substorm morphology, both spatial and temporal. Patterns of low-energy electron precipitation observed by polar satellites are examined as functions of substorm phase. The implications of the precipitation boundaries identifiable at the low-latitude edge of polar cusp electron precipitation and at the poleward edge of precipitation in the premidnight sector are discussed.

  15. Precipitation legacy effects on dryland ecosystem carbon fluxes: direction, magnitude and biogeochemical carryovers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The precipitation legacy effect, defined as the impact of historical precipitation (PPT) on extant ecosystem dynamics, has been recognized as an important driver in shaping the temporal variability of dryland aboveground net primary production (ANPP) and soil respiration. How the PPT legacy influenc...

  16. Multiyear precipitation variations and runoff response in a mixed agricultural grassland watershed in central Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate varies seasonally, from year to year, and also from decade to decade and over longer periods of time. One key climate variable that has great impact on land productivity, runoff, soil erosion and water quality is precipitation. Precipitation drives soil moisture, evapotranspiration, biomass...

  17. Do we have to correct winter precipitation for nowcast applications?

    NASA Astrophysics Data System (ADS)

    Helfricht, Kay; Koch, Roland; Olefs, Marc

    2016-04-01

    In mountain regions like the Alps, a significant fraction of the annual precipitation falls as snow. There is an increasing demand for high-quality analysis, nowcast and short-range forecasts of snowfall. Operational services, such as traffic maintenance, real-time flood-warning systems of hydrological services and avalanche warning products, but also hydropower companies and ski resorts need reliable information on precipitation, snow depth and the corresponding snow water equivalent. However, producing accurate precipitation maps in complex terrain using only remote sensing techniques and uncorrected rain gauge data is a difficult task. In cold and windy conditions, conventional rain gauge measurements are prone to large errors when snow passes the rain gauge and sublimation occurs at heated devices. Empirical correction formulas are given by the WMO to compensate the potential undercatch (Goodison, 2008). The project pluSnow aims to combine snow depth measurements and precipitation data to minimize the error of gauge undercatch on the basis of snow depth data from 63 automatic weather stations (TAWES), operated by the Austrian Central Institute for Meteorology and Geodynamics (ZAMG). These TAWES are equipped with SHM30 laser sensors to measure snow depth with high accuracy and temporal resolution of 0.01 m and 10 minutes, respectively. The pluSnow project will contribute to existing research efforts around the globe which focus on improving the precision of solid precipitation measurements. Here we present a first study based on the original TAWES data between 2006 and 2015. The fraction of solid precipitation to total winter precipitation between November and April (NDJFMA) and the potential undercatch of measured precipitation following Goodison (2008) for all TAWES sorted by altitude are analysed. Examples of the TAWES data in the original high temporal resolution of 10 min are given. The two main parameters used for the correction of precipitation

  18. Acid Precipitation and the Forest Ecosystem

    ERIC Educational Resources Information Center

    Dochinger, Leon S.; Seliga, Thomas A.

    1975-01-01

    The First International Symposium on Acid Precipitation and the Forest Ecosystem dealt with the potential magnitude of the global effects of acid precipitation on aquatic ecosystems, forest soils, and forest vegetation. The problem is discussed in the light of atmospheric chemistry, transport, and precipitation. (Author/BT)

  19. Photoinduced tellurium precipitation in CdTe

    NASA Astrophysics Data System (ADS)

    Sugai, Shunji

    1991-06-01

    Tellurium precipitation in CdTe is found to be induced by photoirradiation with energy higher than the energy gap at 240 W/sq cm. It is suggested that this photoinduced precipitation is related with the strong electron-phonon interactions, possibly self-trapped excitons. This irreducible tellurium precipitation may cause a serious problem for the life of semiconductor devices.

  20. Climate change projections for precipitation in Portugal

    NASA Astrophysics Data System (ADS)

    Andrade, C.; Santos, J. A.

    2013-10-01

    The strong irregularity of precipitation in Portugal, which may e.g. trigger severe/extreme droughts and floods, results in a high vulnerability of the country to precipitation inter-annual variability and to its extremes. Furthermore, dryer future climates are projected for Portugal, though there has also been some growing evidence for a strengthening of precipitation extremes. Due to the central role played byprecipitation on many socio-economic sectors and environmental systems, regional climate change assessments for precipitation in Portugal are necessary. This study is focused on analyzing climate change projections for seasonal (3-month) precipitation totals and their corresponding extremes over mainland Portugal. Taking into account the strong seasonality of the precipitation regimes in Portugal, winter (DJF) and summer (JJA) are considered separately. Precipitation datasets generated by a 16-member ensemble of regional climate model experiments from the ENSEMBLES project are used. Percentile-based indices of precipitation are computed and analyzed for a recent past period (1961-2000) and for a near future period (2041-2070). Results for the R5p, R50p and R95p indices highlight significant projected changes in precipitation, with a clear distinction between northwestern Portugal and the rest of the country in both seasons. Overall, precipitation is projected to decrease in both seasons, particularly over northwestern Portugal in winter, despite some significant regional differences. Although precipitation is projected to decrease in most cases, extremely high seasonal precipitations (above the 95th percentile)areexpected to increase in winter.

  1. [Acute heart failure: precipitating factors and prevention].

    PubMed

    Aramburu Bodas, Oscar; Conde Martel, Alicia; Salamanca Bautista, Prado

    2014-03-01

    Acute heart failure episodes, whether onset or decompensation of a chronic form, are most often precipitated by a concurrent process or disease, described as precipitating factors of heart failure. In this article, we review these precipitating factors, their proportions and clinical relevance in general and in subgroups of patients, their relationship with prognosis, and their possible prevention. PMID:24930077

  2. Microbially Induced Calcite Precipitation for Subsurface Immobilization of Contaminants

    NASA Astrophysics Data System (ADS)

    Smith, R. W.; Fujita, Y.; Ginn, T. R.; Hubbard, S. S.; Dafflon, B.; Delwiche, M.; Gebrehiwet, T.; Henriksen, J. R.; Peterson, J.; Taylor, J. L.

    2011-12-01

    Subsurface radionuclide and metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of the greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent trace ions, such as the short-lived radionuclide 90Sr, is co-precipitation in calcite. We have found that calcite precipitation and co-precipitation of Sr can be accelerated by the activity of urea hydrolyzing microorganisms, that higher calcite precipitation rates can result in increased Sr partitioning, and that nutrient additions can stimulate ureolytic activity. To extend our understanding of microbially induced calcite precipitation (MICP) in an aquifer setting a continuous recirculation field experiment evaluating MICP was conducted at the Integrated Field Research Challenge (IFRC) site located at Rifle, CO. In this experiment, groundwater extracted from an onsite well was amended with urea (total mass of 42.5 kg) and molasses (a carbon and electron donor) and re-injected into a well approximately 4 meters up-gradient for a period of 12 days followed by 10 months of groundwater sampling and monitoring. Crosshole radar and electrical tomographic data were collected prior, during, and after the MICP treatment. The urea and molasses treatment resulted in an enhanced population of sediment associated urea hydrolyzing organisms as evidenced by increases in the number of ureC gene copies, increases in 14C urea hydrolysis rates, and long-term observations of ammonium (a urea hydrolysis product) in the injection, extraction and down gradient monitoring wells. Permeability changes and increases in the calcite saturation indexes in the well field suggest that mineral precipitation has occurred; ongoing analysis of field samples seeks to confirm this. Changes in dielectric constant and electrical conductivity were used to interpret the spatiotemporal distribution of the injectate and subsequent calcite precipitation. Modeling activities are underway to

  3. Precipitation Estimation from Remotely Sensed Data Using Deep Neural Networks

    NASA Astrophysics Data System (ADS)

    Tao, Y.; Gao, X.; Sorooshian, S.

    2014-12-01

    This research develops a precipitation estimation system from remotely-sensed observations using state-of-the-art machine learning algorithms. Compared to ground-based precipitation measurements, satellite-based precipitation estimation products have advantages of temporal resolution and spatial coverage. Also, the massive amount of satellite data contains various measures related to precipitation formation and development. On the other hand, deep learning algorithms were newly developed in the area of machine learning, which was a breakthrough to deal with large and complex dataset, especially to image data. Here, we attempts to engage deep learning techniques to provide hourly precipitation estimation from long wave infrared data from operational geostationary weather satellites. The brightness temperature data from infrared data is considered to contain cloud information. Radar stage IV dataset is used as ground measurement for parameter calibration. Denoising stacked auto-encoders (DSAE) is applied here to build a 4-layer neural network with 1000 hidden nodes for each layer. DSAE involves two major steps: (1) greedily pre-training each layer as an auto-encoder using the outputs of previous trained hidden layer output starting from visible layer to initialize parameters; (2) fine-tuning the whole deep neural network with supervised criteria. Rain/No-rain classification is dealt as the first step of precipitation estimation in this research. Our experiments show that deep neural networks outperform the classic approach originally used in developing the PERSIANN-CCS (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks Cloud Classification System). In an experiment over a 3-month summer period focusing on the central U.S with hourly data, the proposed approach's Probability of Detection (POD) increased to 0.433 as compared to PERSIANN-CCS value of 0.403 and decreased the False Alarm Ratio (FAR) to 0.606 as compared to 0

  4. Effects of ice-phase cloud microphysics in simulating wintertime precipitation

    SciTech Connect

    Kim, Jinwon; Cho, Han-Ru; Soong, Sy-Tzai

    1995-11-01

    We compare two numerical experiments to investigate the effects of ice-phase cloud microphysical processes on simulations of wintertime precipitation in the southwestern United States. Results of these simulations, one with and the other without ice-phase microphysics, suggest that an inclusion of ice-phase microphysics plays a crucial role in simulating wintertime precipitation. The simulation that employs both the ice and water-phase microphysics better reproduced the observed spatial distribution of precipitation compared to the one without ice-phase microphysics. The most significant effect of ice-phase microphysics appeared in local production of precipitating particles by collection processes, rather than in local condensation.

  5. The importance of energetic particle precipitation on the chemical composition of the middle atmosphere

    NASA Technical Reports Server (NTRS)

    Thorne, R. M.

    1980-01-01

    The present review deals with the importance of three distinct classes of precipitation which directly deposit energy into the middle atmosphere, viz. galactic cosmic radiation, energetic solar protons and relativistic electron precipitation from the earth's radiation belts. Chemical considerations during particle precipitation are discussed, with special emphasis on the relative production rate of odd nitrogen and odd hydrogen species during ionizing particle precipitation. The long residence time of NO in the upper stratosphere, where catalytic interaction with O3 is most effective, requires that this mechanism be included in future modeling of global distribution of O3. Other situations causing O3 depletion are also identified.

  6. Precipitation uncertainty propagation in hydrologic simulations: evaluation over the Iberian Peninsula.

    NASA Astrophysics Data System (ADS)

    Nikolopoulos, Efthymios I.; Polcher, Jan; Anagnostou, Emmanouil N.; Eisner, Stephanie; Fink, Gabriel; Kallos, George

    2016-04-01

    Precipitation is arguably one of the most important forcing variables that drive terrestrial water cycle processes. The process of precipitation exhibits significant variability in space and time, is associated with different water phases (liquid or solid) and depends on several other factors (aerosols, orography etc), which make estimation and modeling of this process a particularly challenging task. As such, precipitation information from different sensors/products is associated with uncertainty. Propagation of this uncertainty into hydrologic simulations can have a considerable impact on the accuracy of the simulated hydrologic variables. Therefore, to make hydrologic predictions more useful, it is important to investigate and assess the impact of precipitation uncertainty in hydrologic simulations in order to be able to quantify it and identify ways to minimize it. In this work we investigate the impact of precipitation uncertainty in hydrologic simulations using land surface models (e.g. ORCHIDEE) and global hydrologic models (e.g. WaterGAP3) for the simulation of several hydrologic variables (soil moisture, ET, runoff) over the Iberian Peninsula. Uncertainty in precipitation is assessed by utilizing various sources of precipitation input that include one reference precipitation dataset (SAFRAN), three widely-used satellite precipitation products (TRMM 3B42v7, CMORPH, PERSIANN) and a state-of-the-art reanalysis product (WFDEI) based on the ECMWF ERA-Interim reanalysis. Comparative analysis is based on using the SAFRAN-simulations as reference and it is carried out at different space (0.5deg or regional average) and time (daily or seasonal) scales. Furthermore, as an independent verification, simulated discharge is compared against available discharge observations for selected major rivers of Iberian region. Results allow us to draw conclusions regarding the impact of precipitation uncertainty with respect to i) hydrologic variable of interest, ii

  7. Mesoscale modeling of solute precipitation and radiation damage

    SciTech Connect

    Zhang, Yongfeng; Schwen, Daniel; Ke, Huibin; Bai, Xianming; Hales, Jason

    2015-09-01

    This report summarizes the low length scale effort during FY 2014 in developing mesoscale capabilities for microstructure evolution in reactor pressure vessels. During operation, reactor pressure vessels are subject to hardening and embrittlement caused by irradiation-induced defect accumulation and irradiation-enhanced solute precipitation. Both defect production and solute precipitation start from the atomic scale, and manifest their eventual effects as degradation in engineering-scale properties. To predict the property degradation, multiscale modeling and simulation are needed to deal with the microstructure evolution, and to link the microstructure feature to material properties. In this report, the development of mesoscale capabilities for defect accumulation and solute precipitation are summarized. Atomic-scale efforts that supply information for the mesoscale capabilities are also included.

  8. Evaluating the use of different precipitation datasets in flood modelling

    NASA Astrophysics Data System (ADS)

    Akyurek, Zuhal; Soytekin, Arzu

    2016-04-01

    Satellite based precipitation products, numerical weather prediction model precipitation forecasts and weather radar precipitation estimates can be a remedy for gauge sparse regions especially in flood forecasting studies. However, there is a strong need for evaluation of the performance and limitations of these estimates in hydrology. This study compares the Hydro-Estimator precipitation product, Weather Research and Forecasting (WRF) model precipitation and weather radar values with gauge data in Samsun-Terme region located in the eastern Black Sea region of Turkey, which generally receives high rainfall from north-facing slopes of mountains. Using different statistical factors, performance of the precipitation estimates are compared in point and areal based manner. In point based comparisons, three matching methods; direct matching method (DM), probability matching method (PMM) and window correlation matching method (WCMM) are used to make comparisons for the flood event (22.11.2014) lasted 40 hours. Hourly rainfall data from 13 ground observation stations were used in the analyses. This flood event created 541 m3/sec peak discharge at the 22-45 discharge observation station and flooding at the downstream of the basin. It is seen that, general trend of the rainfall is captured by the radar rainfall estimation well but radar underestimates the peaks. Moreover, it is observed that the assessment factor (gauge rainfall/ radar rainfall estimation) does not depend on the distance between radar and gauge station. In WCMM calculation it is found out that change of space window from 1x1 type to 5x5 type does not improve the results dramatically. In areal based comparisons, it is found out that the distribution of the HE product in time series does not show similarity for other datasets. Furthermore, the geometry of the subbasins, size of the area in 2D and 3D and average elevation do not have an impact on the mean statistics, RMSE, r and bias calculation for both radar

  9. Precipitation intensity and vegetation controls on geomorphology of the central Andes

    NASA Astrophysics Data System (ADS)

    Jeffery, M. L.; Poulsen, C. J.; Ehlers, T. A.; Yanites, B. J.

    2012-12-01

    Field observations and landscape evolution models indicate that landscape processes in active mountain belts are strongly dependent on vegetation and climate. In fluvial landscapes, erosional efficiency is commonly thought to depend on the intensity, frequency, and duration of precipitation events. We use Tropical Rainfall Measuring Mission (TRMM) observations to test the importance of precipitation intensity in determining geomorphology at the mountain belt scale. Precipitation metrics, including mean annual precipitation, and the mean intensity, duration, and frequency of precipitation events, are derived from the TRMM 3B42v7 product. The new precipitation datasets are then compared with different topographic metrics of the central Andes. Statistical analyses, including multiple linear regression, are used to quantify the importance of different precipitation metrics in controlling the regional topographic characteristics. In addition to climate properties, spatial variations in tectonic regime, bedrock lithology, and the amount and type of vegetation cover are accounted for in the statistical analyses. Our analysis indicates that in regions with high vegetation cover (>80%), mean precipitation intensity and mean interval correlate most strongly with mean hillslope (r = -0.51 and r = -0.66 respectively). In these regions, mean hillslope decreases from ~25° to ~ 10° with increasing mean event precipitation intensity (from 10 to 40 mm/day). In contrast, in sparsely vegetated (<40%) or shrub-dominated landscapes, precipitation intensity does not correlate with mean hillslope (r < 0.1). In regions with high vegetation cover, mean annual precipitation is weakly correlated with mean hillslope (r = 0.24). However, mean hillslope increases with increasing mean annual precipitation (r = 0.52) when all vegetation cover is considered. We interpret the results as evidence that vegetation is a key control on critical erosion thresholds at the landscape scale. Furthermore

  10. Skill assessment of precipitation nowcasting in Mediterranean Heavy Precipitation Events

    NASA Astrophysics Data System (ADS)

    Bech, Joan; Berenguer, Marc

    2013-04-01

    Very short-term precipitation forecasting (i.e nowcasting) systems may provide valuable support in the weather surveillance process as they allow to issue automated early warnings for heavy precipitation events (HPE) as reviewed recently by Pierce et al. (2012). The need for warnings is essential in densely populated regions of small catchments, such as those typically found in Mediterranean coastal areas, prone to flash-floods. Several HPEs that occurred in NE Spain are analyzed using a nowcasting system based on the extrapolation of rainfall fields observed with weather radar following a Lagrangian approach developed and tested successfully in previous studies (Berenguer et al. 2005, 2011). Radar-based nowcasts, with lead times up to 3 h, are verified here against quality-controlled weather radar quantitative precipitation estimates and also against a dense network of raingauges. The basic questions studied are the dependence of forecast quality with lead time and rainfall amounts in several high-impact HPEs such as the 7 September 2005 Llobregat Delta river tornado outbreak (Bech et al. 2007) or the 2 November 2008 supercell tornadic thunderstorms (Bech et al. 2011) - both cases had intense rainfall rates (30' amounts exceeding 38.2 and 12.3 mm respectively) and daily values above 100 mm. Verification scores indicated that forecasts of 30' precipitation amounts provided useful guidance for lead times up to 60' for moderate intensities (up to 1 mm in 30') and up to 2.5h for lower rates (above 0.1 mm). On the other hand correlations of radar estimates and forecasts exceeded Eulerian persistence of precipitation estimates for lead times of 1.5 h for moderate intensities (up to 0.8 mm/h). We complete the analysis with a discussion on the reliability of threshold to lead time dependence based on the event-to-event variability found. This work has been done in the framework of the ProFEWS project (CGL2010-15892). References Bech J, N Pineda, T Rigo, M Aran, J Amaro, M

  11. Microbiologically Induced Calcite Precipitation Mediated by Sporosarcina pasteurii.

    PubMed

    Bhaduri, Swayamdipta; Debnath, Nandini; Mitra, Sushanta; Liu, Yang; Kumar, Aloke

    2016-01-01

    The particular bacterium under investigation here (S. pasteurii) is unique in its ability, under the right conditions, to induce the hydrolysis of urea (ureolysis) in naturally occurring environments through secretion of an enzyme urease. This process of ureolysis, through a chain of chemical reactions, leads to the formation of calcium carbonate precipitates. This is known as Microbiologically Induced Calcite Precipitation (MICP). The proper culture protocols for MICP are detailed here. Finally, visualization experiments under different modes of microscopy were performed to understand various aspects of the precipitation process. Techniques like optical microscopy, Scanning Electron Microscopy (SEM) and X-Ray Photo-electron Spectroscopy (XPS) were employed to chemically characterize the end-product. Further, the ability of these precipitates to clog pores inside a natural porous medium was demonstrated through a qualitative experiment where sponge bars were used to mimic a pore-network with a range of length scales. A sponge bar dipped in the culture medium containing the bacterial cells hardens due to the clogging of its pores resulting from the continuous process of chemical precipitation. This hardened sponge bar exhibits superior strength when compared to a control sponge bar which becomes compressed and squeezed under the action of an applied external load, while the hardened bar is able to support the same weight with little deformation. PMID:27167458

  12. Hydrologically-Aided Interpolation (HAI) of Precipitation in Complex Alpine Terrain

    NASA Astrophysics Data System (ADS)

    Riboust, P.; Le Moine, N.; Gailhard, J.; Hendrickx, F.; Garcon, R.; Gottardi, F.

    2015-12-01

    Hydrological modeling in mountainous regions requires unbiaised precipitation estimates at scales of a few hundreds to a few thousands square-kilometers (meso-scale). At these scales, precipitation patterns are complex and exhibit orographic enhancement, a phenomenon which is often poorly captured by scarce gage networks. Usually, the estimation of areal precipitation is performed independently of the hydrological modeling step (e.g. using precipitation reanalysis datasets or gage interpolation products). In this approach, it is not possible to easily correct precipitation biases in the case of discrepancies between observed and simulated discharges. In this study, we introduce the concept of Hydrologically-Aided Interpolation (HAI): a gage-based interpolation scheme, producing gridded daily precipitation estimates, is coupled to a semi-distributed hydrological model running at the daily time-step. The parameters of the interpolation scheme (precipitation gradients with elevation) are estimated jointly with the parameters of the hydrological model (snow scheme, soil moisture accounting scheme, and routing scheme). The whole hydrometeorological model is evaluated against cross-validation precipitation gages, point-scale snow water equivalent (SWE) measurements, and catchment-scale discharge estimates at several streamflow gaging sites in a 3,500 square-kilometer Alpine catchment in the French Southern Alps. Results show that adding hydrological constraints leads to much more robust estimates of precipitation gradients, which in turn produce improved precipitation estimates in temporal cross-validation both at point-scale and catchment-scale.

  13. Isotopic characteristics of Indian precipitation

    NASA Astrophysics Data System (ADS)

    Kumar, Bhishm; Rai, S. P.; Kumar, U. Saravana; Verma, S. K.; Garg, Pankaj; Kumar, S. V. Vijaya; Jaiswal, Rahul; Purendra, B. K.; Kumar, S. R.; Pande, N. G.

    2010-12-01

    Hydrogen (2H/1H) and oxygen (18O/16O) isotopic ratios were measured in precipitation (900 samples) collected from several locations in India during the period 2003-2006 (12 locations in 2003 and 18 locations in 2004-2006). The amount of rainfall along with air temperature and humidity were also measured. The meteoric water line developed for India using isotopic data of precipitation samples, namely, δ2H = 7.93(±0.06) × δ18O + 9.94(±0.51) (n = 272, r2 = 0.98), differs slightly from the global meteoric water line. Regional meteoric water lines were developed for several Indian regions (i.e., northern and southern regions of India, western Himalayas) and found to be different from each other (southern Indian meteoric water line, slope is 7.82, intercept or D excess is 10.23; northern Indian meteoric water line, slope is 8.15, intercept is 9.55) which is attributed to differences in their geographic and meteorological conditions and their associated atmospheric processes (i.e., ambient temperature, humidity, organ, and source of vapor masses). The local meteoric water lines developed for a number of locations show wide variations in the slope and intercept. These variations are due to different vapor sources such as the northeast (NE) monsoon that originates in the Bay of Bengal; the southwest monsoon (SW) that originates in the Arabian Sea; a mixture of NE and SW monsoons; retreat of NE and SW monsoons and western disturbances that originate in the Mediterranean Sea. The altitude effect in the isotopic composition of precipitation estimated for western Himalayan region also varies from month to month.

  14. Precipitation interpolation in mountainous areas

    NASA Astrophysics Data System (ADS)

    Kolberg, Sjur

    2015-04-01

    Different precipitation interpolation techniques as well as external drift covariates are tested and compared in a 26000 km2 mountainous area in Norway, using daily data from 60 stations. The main method of assessment is cross-validation. Annual precipitation in the area varies from below 500 mm to more than 2000 mm. The data were corrected for wind-driven undercatch according to operational standards. While temporal evaluation produce seemingly acceptable at-station correlation values (on average around 0.6), the average daily spatial correlation is less than 0.1. Penalising also bias, Nash-Sutcliffe R2 values are negative for spatial correspondence, and around 0.15 for temporal. Despite largely violated assumptions, plain Kriging produces better results than simple inverse distance weighting. More surprisingly, the presumably 'worst-case' benchmark of no interpolation at all, simply averaging all 60 stations for each day, actually outperformed the standard interpolation techniques. For logistic reasons, high altitudes are under-represented in the gauge network. The possible effect of this was investigated by a) fitting a precipitation lapse rate as an external drift, and b) applying a linear model of orographic enhancement (Smith and Barstad, 2004). These techniques improved the results only marginally. The gauge density in the region is one for each 433 km2; higher than the overall density of the Norwegian national network. Admittedly the cross-validation technique reduces the gauge density, still the results suggest that we are far from able to provide hydrological models with adequate data for the main driving force.

  15. Spatial and altitudinal variation of precipitation and the correction of gridded precipitation datasets for the Upper Indus Basin and the Hindukush-Karakoram-Himalaya

    NASA Astrophysics Data System (ADS)

    Khan, Asif; Richards, Keith S.; Parker, Geoffrey T.; McRobie, Allan; Booij, Martijn J.; Duan, Zheng; Naz, Bibi S.; Lee, Junhak; Khan, Mujahid

    2015-04-01

    have measured and or modelled precipitation for various altitudes and watersheds. For the entire UIB (at Tarbela Dam), the revised annual average precipitation is 794±79 mm/yr compared to the sum of flow and ETact of 877±77 mm/yr, and a glacier melt contribution of about 20-40 mm/yr (6 ± 2% of annual average flows). This provides the best precipitation estimate currently available. This study therefore cautions against use of the gridded data products listed above without substantial effort in bias correction; and argues that previous hydro-climatic studies for the UIB and its region, based on these datasets, need significant re-evaluation,. The precipitation distribution estimated here can, however, be used in the future to correct existing gridded data products and to improve hydro-climatic studies in the Himalayan region.

  16. Hydrocarbonates in precipitation of Moscow

    NASA Astrophysics Data System (ADS)

    Larin, Igor; Eremina, Iren; Aloyan, Artash; Arutunan, Vardan; Chubarova, Natalia; Yermakov, Alexandr

    2016-04-01

    According to monitoring of the atmospheric precipitation of Moscow a number of episodes is revealed, the content of hydrocarbonates in which repeatedly surpasses equilibrium level. Facts of their registration are linked to complex structure of precipitation which is caused by a different chemical composition of condensation nucleus. As a result on the underlying surface two groups of drops with acidity of the different nature are transferred. The acidity of the first, "metal" group of droplets, is determined by a carbonate equilibrium with atmospheric CO2 and with dissolved carbonates of alkali and alkaline earth metals. The acidity of the second, "ammonium" group droplets, is characterized by the balance between an ammonia absorbed from the air and atmospheric acids. Regulation of acidity of the deposits measured in a course of monitoring, occurs for this reason not only in the air, but also in the condensate receiver. A mixing "metal" and "ammonium" groups precipitation accompanied by only a partial transfer of hydrocarbonates in the dissolved CO2. The process is braked as a result of a practical stop of exit of CO2 into the atmosphere because of a mass transfer deceleration. In turn it leads to excess of equilibrium level of hydrocarbonates in the receiver. Estimates show that the acidity of "ammonia" component of precipitation should be much higher than the reported monitoring data. In other words, real acidity of rain drops can essentially exceed that is measured by standard procedures of monitoring of deposits, that it is necessary to take into consideration at calculations of so-called critical levels of acid loading on people and environment. In other words, the actual acidity of raindrops could greatly exceed that is measured by the standard procedures for monitoring rainfall, which should be taken into account when calculating the so-called critical levels of acid loads on people and the environment. It follows that the true level of hazard of acid rain

  17. On the use of radar-based quantitative precipitation estimates for precipitation frequency analysis

    NASA Astrophysics Data System (ADS)

    Eldardiry, Hisham; Habib, Emad; Zhang, Yu

    2015-12-01

    The high spatio-temporal resolutions of radar-based multi-sensor Quantitative Precipitation Estimates (QPEs) makes them a potential complement to the gauge records for engineering design purposes, such as precipitation frequency analysis. The current study investigates three fundamental issues that arise when radar-based QPE products are used in frequency analysis: (a) Effect of sample size due to the typically short records of radar products; (b) Effect of uncertainties present in radar-rainfall estimation algorithms; and (c) Effect of the frequency estimation approach adopted. The study uses a 13-year dataset of hourly, 4 × 4 km2 radar-based over a domain that covers Louisiana, USA. Data-based investigations, as well as synthetic simulations, are performed to quantify the uncertainties associated with the radar-based derived frequencies, and to gain insight into the relative contributions of short record lengths and those from conditional biases in the radar product. Three regional estimation procedures were tested and the results indicate the sensitivity of the radar frequency estimates to the selection of the estimation approach and the impact on the uncertainties of the derived extreme quantiles. The simulation experiments revealed that the relatively short radar records explained the majority of the uncertainty associated with the radar-based quantiles; however, they did not account for any tangible contribution to the systematic underestimation observed between radar- and gauge-based frequency estimates. This underestimation was mostly attributable to the conditional bias inherent in the radar product. Addressing such key outstanding problems in radar-rainfall products is necessary before they can be fully and reliably used for frequency analysis applications.

  18. Comparing peasants' perceptions of precipitation change with precipitation records in the tropical Callejón de Huaylas, Peru

    NASA Astrophysics Data System (ADS)

    Gurgiser, W.; Juen, I.; Singer, K.; Neuburger, M.; Schauwecker, S.; Hofer, M.; Kaser, G.

    2015-10-01

    Pronounced hygric seasonality determines the regional climate and, thus, the characteristics of rain-fed agriculture in the Peruvian Callejón de Huaylas (Cordillera Blanca). Peasants in the Cuenca Auqui on the eastern slopes above the city of Huaraz attribute recently experienced challenges in agricultural production mainly to perceived changes in precipitation patterns. Statistical analyses of daily precipitation records at nearby Recuay (1964 to 2013) and Huaraz (1996 to 2013) stations do not corroborate the perceived changes. Either insufficient temporal resolution of available precipitation records or other environmental and sociopolitical factors impacting traditional farming methods may be the reason for the lack of concordance between the two information sources investigated in this study.

  19. Comparing peasants' perceptions of precipitation change with precipitation records in the tropical Callejón de Huaylas, Peru

    NASA Astrophysics Data System (ADS)

    Gurgiser, Wolfgang; Juen, Irmgard; Singer, Katrin; Neuburger, Martina; Schauwecker, Simone; Hofer, Marlis; Kaser, Georg

    2016-05-01

    Pronounced hygric seasonality determines the regional climate and, thus, the characteristics of rain-fed agriculture in the Peruvian Callejón de Huaylas (Cordillera Blanca). Peasants in the Cuenca Auqui on the eastern slopes above the city of Huaraz attribute recently experienced challenges in agricultural production mainly to perceived changes in precipitation patterns. Statistical analyses of daily precipitation records at nearby Recuay (1964 to 2013) and Huaraz (1996 to 2013) stations do not corroborate the perceived changes. Either insufficient temporal resolution of available precipitation records or other environmental and sociopolitical factors impacting traditional farming methods may be the reason for the lack of concordance between the two information sources investigated in this study.

  20. Complementary information from TRMM and CloudSat to improve our global estimate of precipitation

    NASA Astrophysics Data System (ADS)

    Behrangi, A.; Stephens, G. L.; Adler, R. F.; Huffman, G. J.; Lambrigtsen, B.; Lebsock, M. D.

    2013-12-01

    Complementary information from CloudSat Cloud Profiling Radar (CPR), TRMM PR, and AMSR-E are used to investigate the precipitation detection and estimation performance of a suite of precipitation measuring sensors, commonly used in the production of the merged precipitation products. CPR has high sensitivity to liquid and frozen hydrometeors and can provide added information with respect to the measurement of light rain and snowfall within 80oS-80oN. PR has also enabled significant advancement in quantification of moderate to intense rainfall. The study requires careful consideration of the scale issues among different sensors that will be discussed. Furthermore, we expand the sensor-level analysis to investigate the performance of the global precipitation climatology products: GPCP and CMAP. CloudSat together with TRMM and AMSR-E are used to calculate the mean global precipitation rate and its zonal distribution through a merging process constrained by precipitation occurrence from CloudSat. The three sensors have not been used in GPCP and CMAP thus give us an independent estimate of global precipitation and can be used to understand and assess the strengths and potential weaknesses of the two products. The insights gained from the analysis are found extremely useful to guide our future updates of the products as well as to design future precipitation measuring sensors. The study highlights the important role of GPM to better detect and quantify global precipitation using its Ka/Ku band dual frequency precipitation radar (DPR) and multichannel passive microwave imager (GMI).

  1. Analysis of precipitation appearance in time

    NASA Astrophysics Data System (ADS)

    Bonacci, O.; Matean, D.

    1999-08-01

    This paper analyses precipitation occurrence in time. The calculations were made with the data from continuous precipitation measurements by two automatic float-type rainfall recorders (Hellmann type) during the 10-year period 1984-1993. The measurement increment was 5 minutes with 0.1 mm resolution. The effect of different time increments on precipitation duration in a year has been researched. Calculations show that a smaller time increment diminishes the duration of precipitation in a year. If a 5-minute time increment is used for calculation, the precipitation duration is about 3% of the year. If a 24-hour time increment is used, the precipitation duration is 33% of the year. The real mean duration of yearly precipitation has been evaluated as 216 hours, that is 2.47% of the year. The appearance of a precipitation intensity higher than 0·2 mm/min has been researched during the year and over 24 hours. Analyses show that intensive precipitation appears during the warmer part of the year, from June to August. The precipitation distribution is not uniform over a day. In the city of Zagreb, where both rain gauge stations are situated, in 90% of the cases, the precipitation intensity higher than 1·2 mm/min falls during the night, from 9 p.m. to 1 a.m., at the same time causing floods.

  2. Temperature-precipitation relationships for Canadian stations

    SciTech Connect

    Isaac, G.A. ); Stuart, R.A. )

    1992-08-01

    The dependence of daily precipitation upon average daily temperature has been examined for all seasons using climatological data from 56 stations across Canada. For east and west coast sites, and the north, more precipitation occurs with warm and cold temperatures during January and July, respectively. In the middle of the country, the temperature dependence tends to increase toward the Arctic, with strong dependencies in the Northwest Territories and weaker dependencies on the Prairies. Southern Ontario and Quebec show almost no dependence of precipitation upon temperature during July, but more precipitation falls during warm weather during the winter. For stations within and immediately downwind of the Rockies, for all seasons, more precipitation occurs when the temperature is colder. These temperature-precipitation relationships can provide information on precipitation formation processes, as well as assistance in weather and climate forecasting.

  3. The oceanic shipboard precipitation measurement network for surface validation - OceanRAIN

    NASA Astrophysics Data System (ADS)

    Klepp, Christian

    2015-09-01

    Systematic high quality oceanic in-situ precipitation measurements are requested on an international science level and are essential for improved understanding and validation of hydrological processes in satellite, re-analysis and model data. OceanRAIN, the shipboard "Ocean Rainfall And Ice-phase precipitation measurement Network" for surface validation is, to date, the only systematic long-term disdrometer-based oceanic shipboard precipitation data collection effort to establish a comprehensive statistical basis of precipitation for all climate related hotspots over the global oceans. OceanRAIN utilizes automated disdrometer systems (ODM470) capable of measuring precipitation occurrence, intensity and accumulation and discriminates for rain, snow and mixed-phase precipitation through minute-based particle size distributions. The ODM470 was especially designed for shipboard operation under high and frequently varying wind speeds and rough sea states. This paper provides an overview on the OceanRAIN project, the instrumentation, algorithms, methodology, and data products. The procedure of the data processing chain is outlined, including calibration, shipboard operation, data ingest and quality control. The selected research ships do not circumvent high impact weather, allowing for a collection of the full precipitation spectrum including extremes. By October 2014 the fast growing OceanRAIN database comprised more than 3.7 million minutes of precipitation measurements (including true zeros) since its start in 2010. OceanRAIN aims at increasing knowledge about oceanic precipitation, improving error characterization of GPM (Global Precipitation Measurement) era precipitation retrievals, adding to the continual improvement of the satellite retrieval algorithms, as well as benchmarking existing satellite-based climatologies, re-analysis and model data. The accumulating data volume can be utilized for statistical and process study applications on different temporal and

  4. Analysis of long term trends of precipitation estimates acquired using radar network in Turkey

    NASA Astrophysics Data System (ADS)

    Tugrul Yilmaz, M.; Yucel, Ismail; Kamil Yilmaz, Koray

    2016-04-01

    Precipitation estimates, a vital input in many hydrological and agricultural studies, can be obtained using many different platforms (ground station-, radar-, model-, satellite-based). Satellite- and model-based estimates are spatially continuous datasets, however they lack the high resolution information many applications often require. Station-based values are actual precipitation observations, however they suffer from their nature that they are point data. These datasets may be interpolated however such end-products may have large errors over remote locations with different climate/topography/etc than the areas stations are installed. Radars have the particular advantage of having high spatial resolution information over land even though accuracy of radar-based precipitation estimates depends on the Z-R relationship, mountain blockage, target distance from the radar, spurious echoes resulting from anomalous propagation of the radar beam, bright band contamination and ground clutter. A viable method to obtain spatially and temporally high resolution consistent precipitation information is merging radar and station data to take advantage of each retrieval platform. An optimally merged product is particularly important in Turkey where complex topography exerts strong controls on the precipitation regime and in turn hampers observation efforts. There are currently 10 (additional 7 are planned) weather radars over Turkey obtaining precipitation information since 2007. This study aims to optimally merge radar precipitation data with station based observations to introduce a station-radar blended precipitation product. This study was supported by TUBITAK fund # 114Y676.

  5. Precipitation chemistry in central Amazonia

    NASA Technical Reports Server (NTRS)

    Andreae, M. O.; Talbot, R. W.; Berresheim, H.; Beecher, K. M.

    1990-01-01

    Rain samples from three sites in central Amazonia were collected over a period of 6 weeks during the 1987 wet season and analyzed for ionic species and dissolved organic carbon. A continuous record of precipitation chemistry and amount was obtained at two of these sites, which were free from local or regional pollution, for a time period of over 1 month. The volume-weighted mean concentrations of most species were found to be about a factor of 5 lower during the wet season compared with previous results from the dry season. Only sodium, potassium, and chloride showed similar concentrations in both seasons. When the seasonal difference in rainfall amount is taken into consideration, the deposition fluxes are only slightly lower for most species during the wet season than during the dry season, again with the exception of chloride, potassium, and sodium. Sodium and chloride are present in the same ratio as in sea salt; rapid advection of air masses of marine origin to the central Amazon Basin during the wet season may be responsible for the observed higher deposition flux of these species. Statistical analysis suggests that sulfate is, to a large extent, of marine (sea salt and biogenic) origin, but that long-range transport of combustion-derived aerosols also makes a significant contribution to sulfate and nitrate levels in Amazonian rain. Organic acid concentrations in rain were responsible for a large fraction of the observed precipitation acidity; their concentration was strongly influenced by gas/liquid interactions.

  6. Hemispheric Assymeries in Auroral Precipitation

    NASA Astrophysics Data System (ADS)

    Mende, S. B.

    2014-12-01

    It is widely accepted that the space weather related electrodynamic forcing of the geospace environment acts through the high geomagnetic latitude regions. At high latitudes inter-hemispheric asymmetries are largely due to the differences in solar illumination, the direction of the solar wind and interplanetary magnetic field components and to a lesser extent, due to differences between the two hemispheric internal fields. So far most research regarding interhemispheric differences concentrated on learning about the basic magnetosphere-ionosphere coupling mechanisms. It has been well established that sunlit conditions affect the energy flux of auroral precipitation resulting from the reduction in the mean energy of the auroral electrons in the sunlit summer hemisphere. This can be explained by the partial shorting out of the particle accelerating fields by the sunlight induced conductivity. It has also been found that sunlit conditions reduce the particle fluxes and therefore the associated field aligned currents. Unless the precipitation-induced conductivities overwhelm the sunlit component of conductivity, this would imply that the magnetospheric current generator responds to the ionospheric load in a highly non-linear manner. Interhemispheric currents may also play an important role that has not been fully explored. Interhemispheric asymmetries in substorm morphology have been explored critically because conjugacy implies that substorms have a common source at equatorial latitudes. In some cases the lack of conjugacy of substorms could be explained by considering the magnitude and direction of the IMF.

  7. How well can we estimate error variance of satellite precipitation data around the world?

    NASA Astrophysics Data System (ADS)

    Gebregiorgis, Abebe S.; Hossain, Faisal

    2015-03-01

    Providing error information associated with existing satellite precipitation estimates is crucial to advancing applications in hydrologic modeling. In this study, we present a method of estimating the square difference prediction of satellite precipitation (hereafter used synonymously with "error variance") using regression model for three satellite precipitation products (3B42RT, CMORPH, and PERSIANN-CCS) using easily available geophysical features and satellite precipitation rate. Building on a suite of recent studies that have developed the error variance models, the goal of this work is to explore how well the method works around the world in diverse geophysical settings. Topography, climate, and seasons are considered as the governing factors to segregate the satellite precipitation uncertainty and fit a nonlinear regression equation as a function of satellite precipitation rate. The error variance models were tested on USA, Asia, Middle East, and Mediterranean region. Rain-gauge based precipitation product was used to validate the error variance of satellite precipitation products. The regression approach yielded good performance skill with high correlation between simulated and observed error variances. The correlation ranged from 0.46 to 0.98 during the independent validation period. In most cases (~ 85% of the scenarios), the correlation was higher than 0.72. The error variance models also captured the spatial distribution of observed error variance adequately for all study regions while producing unbiased residual error. The approach is promising for regions where missed precipitation is not a common occurrence in satellite precipitation estimation. Our study attests that transferability of model estimators (which help to estimate the error variance) from one region to another is practically possible by leveraging the similarity in geophysical features. Therefore, the quantitative picture of satellite precipitation error over ungauged regions can be

  8. Global scale precipitation from monthly to centennial scales: empirical space-time scaling analysis, anthropogenic effects

    NASA Astrophysics Data System (ADS)

    de Lima, Isabel; Lovejoy, Shaun

    2016-04-01

    The characterization of precipitation scaling regimes represents a key contribution to the improved understanding of space-time precipitation variability, which is the focus here. We conduct space-time scaling analyses of spectra and Haar fluctuations in precipitation, using three global scale precipitation products (one instrument based, one reanalysis based, one satellite and gauge based), from monthly to centennial scales and planetary down to several hundred kilometers in spatial scale. Results show the presence - similarly to other atmospheric fields - of an intermediate "macroweather" regime between the familiar weather and climate regimes: we characterize systematically the macroweather precipitation temporal and spatial, and joint space-time statistics and variability, and the outer scale limit of temporal scaling. These regimes qualitatively and quantitatively alternate in the way fluctuations vary with scale. In the macroweather regime, the fluctuations diminish with time scale (this is important for seasonal, annual, and decadal forecasts) while anthropogenic effects increase with time scale. Our approach determines the time scale at which the anthropogenic signal can be detected above the natural variability noise: the critical scale is about 20 - 40 yrs (depending on the product, on the spatial scale). This explains for example why studies that use data covering only a few decades do not easily give evidence of anthropogenic changes in precipitation, as a consequence of warming: the period is too short. Overall, while showing that precipitation can be modeled with space-time scaling processes, our results clarify the different precipitation scaling regimes and further allow us to quantify the agreement (and lack of agreement) of the precipitation products as a function of space and time scales. Moreover, this work contributes to clarify a basic problem in hydro-climatology, which is to measure precipitation trends at decadal and longer scales and to

  9. Challenges in precipitation observation and analysis over the cold/mountain regions

    NASA Astrophysics Data System (ADS)

    Yang, D.; Zhang, Y.; Ma, Y.

    2012-12-01

    Precipitation is one of the most important variables for climate, hydrology, glacier, and ecosystem research at local, regional, and global scales. It is a great challenge to compile regional precipitation datasets and to develop reliable products for various research activities over the cold regions, i.e. the high altitudes and high latitudes. The TPE program has recognized the urgent need and critical importance for accurate regional precipitation datasets and products. This presentation will show new results from regional analyses of surface and remote sensing precipitation datasets for the TPE. It will also discuss key issues in cold region precipitation research, such as compatibility of data/observations over the national borders, bias-correction methods and results, and common challenges and linkages between high-latitude and high-altitude regions.

  10. Precipitate hydrolysis experimental facility (PHEF): Run 64 report

    SciTech Connect

    Lambert, D.P.; Edwards, R.E.; Shah, H.B.; Young, S.R.

    1994-07-29

    The significant findings of Run 64 are: (a) Carbon dioxide was demonstrated to be an acceptable inertant for the actual hydrolysis process. However, based on the severe degradation of the tetraphenylborate (TPB) precipitate slurry stored in the Precipitate Hold Tank (PHT) at PHEF following Run 65, further evaluation of the suitability of carbon dioxide as an inertant for the long term storage of precipitate slurries is warranted. (b) Phenylboronic acid (PBA) reaction kinetics were excellent with no detectable PBA in Precipitate Hydrolysis Aqueous (PHA) product. (c) PHA product was low in biphenyl (6 mg/l), diphenylamine (13 mg/l), and total high boiling organics (22 mg/l). (d) Reproduced vacuum collapse problems encountered in DWPF (Defense Waste Processing Facility) water runs and demonstrated that the high vacuums experience during water runs could not be reproduced under normal operating conditions. (e) High benzene losses through stack and fugitive emissions were noted during Run 64. This may lead to poor decanter extraction performance long term and may be problem in DWPF, especially during long lay-ups or at low attainments. Approximately 69% of the benzene produced during Run 64 was released as benzene emissions.

  11. Early assessment of Integrated Multi-satellite Retrievals for Global Precipitation Measurement over China

    NASA Astrophysics Data System (ADS)

    Guo, Hao; Chen, Sheng; Bao, Anming; Behrangi, Ali; Hong, Yang; Ndayisaba, Felix; Hu, Junjun; Stepanian, Phillip M.

    2016-07-01

    Two post-real time precipitation products from the Integrated Multi-satellite Retrievals for Global Precipitation Measurement Mission (IMERG) are systematically evaluated over China with China daily Precipitation Analysis Product (CPAP) as reference. The IMERG products include the gauge-corrected IMERG product (IMERG_Cal) and the version of IMERG without direct gauge correction (IMERG_Uncal). The post-research TRMM Multisatellite Precipitation Analysis version 7 (TMPA-3B42V7) is also evaluated concurrently with IMERG for better perspective. In order to be consistent with CPAP, the evaluation and comparison of selected products are performed at 0.25° and daily resolutions from 12 March 2014 through 28 February 2015. The results show that: Both IMERG and 3B42V7 show similar performances. Compared to IMERG_Uncal, IMERG_Cal shows significant improvement in overall and conditional bias and in the correlation coefficient. Both IMERG_Cal and IMERG_Uncal perform relatively poor in winter and over-detect slight precipitation events in northwestern China. As an early validation of the GPM-era IMERG products that inherit the TRMM-era global satellite precipitation products, these findings will provide useful feedbacks and insights for algorithm developers and data users over China and beyond.

  12. Status of High Latitude Precipitation Estimates: The Role of GPM in Advancing our Current Understanding

    NASA Astrophysics Data System (ADS)

    Behrangi, A.; Richardson, M.; Christensen, M.; Huffman, G. J.; Adler, R. F.; Stephens, G. L.; Lambrigtsen, B.

    2015-12-01

    This presentation reviews the current status of precipitation estimation from observation and reanalysis at high latitudes and discusses new insights gained by GPM. An intercomparison of high-latitude precipitation characteristics from observation-based and reanalysis products is performed. Precipitation products from GPM and the cloud profiling radar on the CloudSat satellite provide an independent assessment to other products which have already been widely used, these being the observationally-based GPCP, GPCC and CMAP and the reanalyses ERA-Interim, MERRA and NCEP-DOE. Seasonal and annual total precipitation in both hemispheres poleward of 55° latitude is considered in all products, and GPM and CloudSat products are used to assess frequency of precipitation occurrence by phase, defined as rain, snow or mixed phase. Estimates of snowfall over Antarctica and Greenland are compared from various products. A number of disagreements on regional or seasonal scales are identified which will be reported and discussed. These estimates from observations and reanalyses provide useful insights for diagnostic assessment of precipitation products in high latitudes, quantifying the current uncertainties among observations and reanalyses, and establishing a benchmark for assessment of climate models.

  13. Niobium carbide and tin precipitation in continuously cast microalloyed steels

    NASA Astrophysics Data System (ADS)

    Stock, Julian

    With high yield strength, toughness and good weldability, microalloyed steels are widely used in the automotive, pipeline and transportation industries. Microalloying elements such as niobium (Nb), titanium (Ti) and vanadium (V) in concentrations of less than 0.1 wt. pct. are typical. For optimal benefits in the final product, it is usually desired for Ti to form fine precipitates during and after solidification and for Nb to be in solution prior to hot-rolling. Vanadium precipitates at lower temperatures and is less involved in the solidification/casting process. In one aspect of the investigation, the effects of cooling rate on the titanium nitride (TiN) precipitation size distribution were investigated in a Ti-added low-carbon steel. Prior research reported an inverse relationship between the average TiN precipitation size and the post-solidification cooling rate and the present work was undertaken to examine this behavior over a wider range of cooling rates. Using the GleebleRTM 3500's casting simulation capabilities along with controlled cooling rates, the TiN precipitation behavior in thick-slab, thin-slab and thin-strip material was simulated using a commercially produced 0.04C, 1.23Mn steel with near-stoichiometric Ti and N levels. Transmission electron microscopy (TEM) investigation of carbon extraction replicas was carried out to characterize the influence of cooling rates on precipitate size distributions. Decreasing particle sizes with increasing cooling rates were found. Average particle sizes as low as 6.7 nm were present in thin-strip simulations and might be of interest, as fine particles could contribute to strengthening of rapidly cooled steels. In a second aspect of the investigation, niobium carbide (NbC) precipitation during the compact strip production (CSP) process was investigated in two Nb-added low-carbon steels. Instead of industrial sampling, the GleebleRTM was used for casting simulations using two CMn(Nb) steels with high and low- Nb

  14. Wide Band Power and Harmonic Amplitude of Five Precipitation Sets

    NASA Astrophysics Data System (ADS)

    Ruane, A. C.; Roads, J. O.

    2006-12-01

    Time series of precipitation from three high resolution precipitation products (TRMM 3B-42, CMORPH, and PERSIANN) and two reanalysis models (the NCEP/NCAR Reanalysis-2 and an ECPC Seasonal Forecast Model reanalysis) are examined for their frequency characteristics using both harmonic and Fourier approaches. Power spectra generated by fast-Fourier transforms are divided into wide bands comprising the low-frequency (period greater than 30 days), synoptic (period between 2 30 days), and high-frequency (period less than 2 days) components. Low-frequency variability is generally the weakest component, but is amplified over the Inter-Tropical Convergence Zone and monsoonal regions. Land areas feature enhanced high- frequency variability and reduced synoptic variability in comparison to the surrounding oceans. The diurnal and semidiurnal harmonics explain very little of the variance, suggesting that the harmonic approach does a poor job of capturing the high-frequency variability of the datasets. Inter-product and inter-model differences also indicate biases of the precipitation product algorithms and convective parameterizations, including a strong bias toward low-frequency variability in the Relaxed Arakawa-Schubert parameterization employed by the ECPC Seasonal Forecast Model, as well as increased high-frequency power in the TRMM 3B-42 product.

  15. Orbital checkout result of the dual-frequency precipitation radar on the global precipitation measurement core spacecraft

    NASA Astrophysics Data System (ADS)

    Furukawa, K.; Kojima, M.; Miura, T.; Hyakusoku, Y.; Kai, H.; Ishikiri, T.; Iguchi, T.; Hanado, H.; Nakagawa, K.; Okumura, M.

    2014-10-01

    The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. JAXA and NICT developed the DPR through procurement. The contract for DPR was awarded to NEC TOSHIBA Space Systems, Ltd. The configuration of precipitation measurement using active radar and a passive radiometer is similar to TRMM. The major difference is that DPR is used in GPM instead of the precipitation radar (PR) in TRMM. The inclination of the core satellite is 65 degrees, and the flight altitude is about 407 km. The non-sun-synchronous circular orbit is necessary for measuring the diurnal change of rainfall similarly to TRMM. The DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). Both KuPR and KaPR have almost the same design as TRMM PR. The DPR system design and performance were verified through the development test and the proto flight test. DPR had handed over to NASA and integration of the DPR to the GPM core spacecraft had completed in May 2012. GPM core spacecraft satellite system test had completed in November 2013

  16. The Status of NASA's Global Precipitation Measurement (GPM) Mission 26 Months After Launch

    NASA Astrophysics Data System (ADS)

    Jackson, Gail; Huffman, George

    2016-04-01

    Water is essential to our planet Earth. Knowing when, where and how precipitation falls is crucial for understanding the linkages between the Earth's water and energy cycles and is extraordinarily important for sustaining life on our planet during climate change. The Global Precipitation Measurement (GPM) Core Observatory spacecraft launched February 27, 2014, is the anchor to the GPM international satellite mission to unify and advance precipitation measurements from a constellation of research and operational sensors to provide "next-generation" precipitation products [1-2]. GPM is currently a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA). The unique 65o non-Sun-synchronous orbit at an altitude of 407 km for the GPM Core Observatory allows for highly sophisticated observations of precipitation in the mid-latitudes where a majority of the population lives. Indeed, the GOM Core Observatory serves as the cornerstone, as a physics observatory and a calibration reference to improve precipitation measurements by a constellation of 8 or more dedicated and operational, U.S. and international passive microwave sensors. GPM's requirements are to measure rain rates from 0.2 to 110 mm/hr and to detect and estimate falling snow. GPM has several retrieval product levels ranging from raw instrument data to Core and partner swath precipitation estimates to gridded and accumulated products and finally to multi-satellite merged products. The latter merged product, called IMERG, is available with a 5-hour latency with temporal resolution of 30 minutes and spatial resolution of 0.1o x 0.1o (~10km x 10km) grid box. Some products have a 1-hour latency for societal applications such as floods, landslides, hurricanes, blizzards, and typhoons and all have late-latency high-quality science products. The GPM mission is well on its way to providing essential data on precipitation (rain and snow) from micro to local to global scales via providing precipitation

  17. Precipitation climate maps of Belgium

    NASA Astrophysics Data System (ADS)

    Journée, M.; Delvaux, C.; Bertrand, C.

    2015-04-01

    Investigations are conducted to best estimate precipitation climate maps over Belgium from daily observations available for the period 1981-2010. Several mapping approaches are compared in a cross-validation exercise. These approaches differ by several aspects and in particular by the order in which the temporal aggregation (i.e. computation of climate mean values from daily data) and spatial interpolation steps are performed, and by the integration of ancillary information in the spatial interpolation method. The selected approach is used to derive a large panel of climate maps. In particular, the main spatio-temporal features of the annual cycle of rainfall in Belgium are extracted by principal component analysis (PCA).

  18. Approaches and Data Quality for Global Precipitation Estimation

    NASA Astrophysics Data System (ADS)

    Huffman, G. J.; Bolvin, D. T.; Nelkin, E. J.

    2015-12-01

    The space and time scales on which precipitation varies are small compared to the satellite coverage that we have, so it is necessary to merge "all" of the available satellite estimates. Differing retrieval capabilities from the various satellites require inter-calibration for the satellite estimates, while "morphing", i.e., Lagrangian time interpolation, is used to lengthen the period over which time interpolation is valid. Additionally, estimates from geostationary-Earth-orbit infrared data are plentiful, but of sufficiently lower quality compared to low-Earth-orbit passive microwave estimates that they are only used when needed. Finally, monthly surface precipitation gauge data can be used to reduce bias and improve patterns of occurrence for monthly satellite data, and short-interval satellite estimates can be improved with a simple scaling such that they sum to the monthly satellite-gauge combination. The presentation will briefly consider some of the design decisions for practical computation of the Global Precipitation Measurement (GPM) mission product Integrated Multi-satellitE Retrievals for GPM (IMERG), then examine design choices that maximize value for end users. For example, data fields are provided in the output file that provide insight into the basis for the estimated precipitation, including error, sensor providing the estimate, precipitation phase (solid/liquid), and intermediate precipitation estimates. Another important initiative is successive computations for the same data date/time at longer latencies as additional data are received, which for IMERG is currently done at 6 hours, 16 hours, and 3 months after observation time. Importantly, users require long records for each latency, which runs counter to the data archiving practices at most archive sites. As well, the assignment of Digital Object Identifiers (DOI's) for near-real-time data sets (at 6 and 16 hours for IMERG) is not a settled issue.

  19. Manganese Influences Carbonate Precipitation in a Laminated Microbial Mat

    NASA Astrophysics Data System (ADS)

    Krusor, M.; Grim, S. L.; Wilmeth, D.; Johnson, H.; Berelson, W.; Stevenson, B. S.; Stamps, B. W.; Corsetti, F. A.; Spear, J. R.

    2015-12-01

    Investigating mineralization within modern microbial mats informs our interpretation of ancient microbialites and the mineralization process. Microbial mats in Little Hot Creek (LHC), California contain 4 distinct layers with different microbiota. Each layer of the mat is supersaturated with regard to calcium carbonate (CaCO3), which increases with depth. Total organic carbon decreases with depth through the mat. We used 13C-labeled bicarbonate incubations of each mat layer to calculate growth rates of organic carbon and CaCO3 within the mat. Incubations were also amended with Mn or Mg to test their effect on rates of CaCO3 and organic carbon formation. The Mn-amended top layer increased CaCO3 precipitation and organic carbon growth. Mn increased organic carbon production in the lowest layer to a lesser extent, but not growth of CaCO3. Mn addition had no effect on growth rates in the two intervening layers. Mg amendment stimulated only organic carbon formation in the top layer, with little to no effect on the lower layers or overall CaCO3 formation. We attribute the elevated CaCO3 precipitation noted after Mn addition to increased oxygenic photosynthetic activity. Oxygenic photosynthesis requires Mn as an enzyme cofactor and promotes carbonate precipitation. We propose that the phototrophic community was responsible for most of the CaCO3 precipitation in the upper layer. Phototrophs gradually moved upwards for optimal access to sunlight, and as the mat grew, "tenant" microorganisms inhabited the lower carbonate layers while the "builders" remained on top. The relatively constant percentages of inorganic carbon below the top layer combined with observed minimal CaCO3 precipitation under laboratory conditions suggest that additional research into potential metabolisms that impact carbonate formation would be informative. These results improve our understanding of the linkages between microbial metabolisms, carbonate precipitation in microbial mats, and the potential

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

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  1. Improving Access to Precipitation Data for GIS Users: Designing for Ease of Use

    NASA Technical Reports Server (NTRS)

    Stocker, Erich F.; Kelley, Owen A.

    2007-01-01

    The Global Precipitation Measurement Mission (GPM) is a NASA/JAXA led international mission to configure a constellation of space-based radiometers to monitor precipitation over the globe. The GPM goal of making global 3-hour precipitation products available in near real-time will make such global products more useful to a broader community of modelers and Geographic Information Systems (GIS) users than is currently the case with remote sensed precipitation products. Based on the existing interest to make Tropical Rainfall Measuring Mission (TRMM) data available to a growing community of GIS users as well as what will certainly be an expanded community during the GPM era, it is clear that data systems must make a greater effort to provide data in formats easily used by GIS. We describe precipitation GIS products being developed for TRMM data. These products will serve as prototypes for production efforts during the GPM era. We describe efforts to convert TRMM precipitation data to GeoTIFF, Shapefile, and ASCII grid. Clearly, our goal is to format GPM data so that it can be easily used within GIS applications. We desire feedback on these efforts and any additions or direction changes that should be undertaken by the data system.

  2. Physiology-based prognostic modeling of the influence of changes in precipitation on a keystone dryland plant species.

    PubMed

    Coe, Kirsten K; Sparks, Jed P

    2014-12-01

    Fluctuations in mean annual precipitation (MAP) will strongly influence the ecology of dryland ecosystems in the future, yet, because individual precipitation events drive growth and resource availability for many dryland organisms, changes in intra-annual precipitation may disproportionately influence future dryland processes. This work examines the hypothesis that intra-annual precipitation changes will drive dryland productivity to a greater extent than changes to MAP. To test this hypothesis, we created a physiology-based model to predict the effects of precipitation change on a widespread biocrust moss that regulates soil structure, water retention, and nutrient cycling in drylands. First, we used the model to examine moss productivity over the next 100 years driven by alterations in MAP by ± 10, 20 and 30%, and changes in intra-annual precipitation (event size and frequency). Productivity increased as a function of MAP, but differed among simulations where intra-annual precipitation was manipulated under constant MAP. Supporting our hypothesis, this demonstrates that, even if MAP does not change, changes in the features of individual precipitation events can strongly influence long-term performance. Second, we used the model to examine 100-year productivity based on projected dryland precipitation from published global and regional models. These simulations predicted 25-63% reductions in productivity and increased moss mortality rates, declines that will likely alter water and nutrient cycling in dryland ecosystems. Intra-annual precipitation in model-based simulations was a stronger predictor of productivity compared to MAP, further supporting our hypothesis, and illustrating that intra-annual precipitation patterns may dominate dryland responses to altered precipitation in a future climate. PMID:25193314

  3. Mechanisms affecting swelling in alloys with precipitates

    SciTech Connect

    Mansur, L.K.; Haynes, M.R.; Lee, E.H.

    1980-01-01

    In alloys under irradiation many mechanisms exist that couple phase instability to cavity swelling. These are compounded with the more familiar mechanisms associated with point defect behavior and the evolution of microstructure. The mechanisms may be classified according to three modes of operation. Some affect cavity swelling directly by cavity-precipitate particle association, others operate indirectly by precipitate-induced changes in sinks other than cavities and finally there are mechanisms that are mediated by precipitate-induced changes in the host matrix. The physics of one mechanism of each type is developed in detail and the results compared where possible to experimental measurements. In particular, we develop the theory necessary to treat the effects on swelling of precipitation-induced changes in overall sink density; precipitation-induced changes in point defect trapping by solute depletion and creation of precipitate particle-matrix interfacial trap sites.

  4. Mesospheric Odd Nitrogen Enhancements During Relativistic Electron Precipitation Events

    NASA Technical Reports Server (NTRS)

    Aikin, A. C.; Smith, H. J. P.

    1999-01-01

    The behavior of mesospheric odd nitrogen species during and following relativistic and diffuse auroral precipitation events is simulated, Below 75 km nitric oxide is enhanced in proportion to the ion pair production function associated with the electron precipitation and the length of the event. Nitrogen dioxide and nitric acid are also enhanced. At 65 km the percentage of odd nitrogen for N is 0.1%, HNO3 is 1.6%, NO2 is 15%, and NO is 83.3%. Between 75 and 85 km NO is depleted during particle events due to the faster destruction of NO by N relative to the production of NO by N reacting with O2. Recovery of NO depends on transport from the lower thermosphere, where NO is produced in abundant amounts during particle events.

  5. Precipitation-strengthening effects in iron-aluminides

    SciTech Connect

    Maziasz, P.J.; McKamey, C.G.; Goodwin, G.M.

    1995-05-01

    The purpose of this work is to produce precipitation to improve both high-temperature strength and room-temperature ductibility in FeAl-type(B2 phase) iron-aluminides. Previous work has focused on primarily wrought products, but stable precipitates can also refine the grain size and affect the properties of as-cast and/or welded material as well. New work began in FY 1994 on the properties of these weldable, strong FeAl alloys in the as-cast condition. Because the end product of this project is components for industry testing, simpler and better (cheaper, near-net-shape) processing methods must be developed for industrial applications of FeAl alloys.

  6. Comparison of Eight Different Precipitation Datasets for South America

    NASA Astrophysics Data System (ADS)

    Pinto, L. C.; Costa, M. H.; Diniz, L. F.

    2007-05-01

    Long and continuous meteorological data series for large areas are hard to obtain, so several groups have developed climate datasets generated through the combination of models and observed and remote sensing data, including reanalysis products. This study compares eight different precipitation datasets for South America (NCEP/NCAR-2, ERA-40, CMAP, GPCP, CRU, CPTEC, TRMM, Legates and Willmott, Leemans and Cramer). For each dataset, we analyze the four moments of the data distribution (mean, variance, skewness, kurtosis), for latitudinal variation, for the major river basins and for the major vegetation types in the continent, allowing to identify the geographical variations in each dataset. We verified that significant differences exist among the precipitation products.

  7. Use of polyaspartate as inhibitor of tartaric precipitations in wines.

    PubMed

    Bosso, Antonella; Panero, Loretta; Petrozziello, Maurizio; Sollazzo, Marco; Asproudi, Andriani; Motta, Silvia; Guaita, Massimo

    2015-10-15

    All additives used to stabilize wines against the precipitations of potassium bitartrate have some limits: metatartaric acid (MTA) is effective but very unstable, carboxymethylcellulose is stable and effective in white wines but affects color stability in red wines, mannoproteins have a variable effectiveness depending on wine composition. This work was aimed at testing the effect of new stabilizing products on tartaric precipitations, focusing on the use of Na and K polyaspartate salts (PASPs). The effectiveness of 4 different PASPs and 1 MTA added to red and white wines was compared using the mini-contact test and cold test. The dose effect and the stability of the products over time were also studied. The PASPs showed a similar stabilizing effect and a longer stability over time compared to MTA. PASPs can be considered interesting as additives for wine tartaric stabilization. Further work is in progress to better characterize their enological properties. PMID:25952834

  8. The Value of Real-time High Resolution Satellite Precipitation in Capturing Extreme Rainfall Event

    NASA Astrophysics Data System (ADS)

    Imam, B.; Kuranjekar, P.; Behrangi, A.; Hsu, K.; Sorooshian, S.

    2008-05-01

    In many parts of the world, operational real-time flood and hydrologic forecasting are hindered by the lack of reliable real-time precipitation observations. The insufficient ground observations have made satellite-based precipitation estimates the only available source for wide coverage data. As the spatial and temporal resolution of satellite-based rainfall estimates continue to improve, assessing the usefulness of these products, particularly in capturing extreme precipitation events becomes an important issue. This presentation demonstrates and discusses a framework for evaluating real-time high resolution precipitation products in terms of their operational utility. As an example of operational high resolution precipitation products, the 3 hourly near real-time, 0.04°x0.04° Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS) (Hong et. al., 2004) product is compared against gauge and NEXRAD observations of several heavy precipitation events including tropical storm Erin, which affected Texas and Oklahoma during the period of August 10-20, 2007. For each storm, a swath of precipitation along the storm track is analyzed using both real-time and quality controlled versions of the products. Traditional as well as threshold- based (e.g. verification) performance measures are used to describe differences between NEXRAD and Satellite observations' ability to capture severe storm characteristics within the target area and to assess possible shifts in rainfall amount spectrum. While not fully conclusive, the results indicate that for operational purposes, high resolution satellite-based precipitation estimates can fill in a much needed observational gap during severe storm events.

  9. An appraisal of precipitation distribution in the high-altitude catchments of the Indus basin.

    PubMed

    Dahri, Zakir Hussain; Ludwig, Fulco; Moors, Eddy; Ahmad, Bashir; Khan, Asif; Kabat, Pavel

    2016-04-01

    Scarcity of in-situ observations coupled with high orographic influences has prevented a comprehensive assessment of precipitation distribution in the high-altitude catchments of Indus basin. Available data are generally fragmented and scattered with different organizations and mostly cover the valleys. Here, we combine most of the available station data with the indirect precipitation estimates at the accumulation zones of major glaciers to analyse altitudinal dependency of precipitation in the high-altitude Indus basin. The available observations signified the importance of orography in each sub-hydrological basin but could not infer an accurate distribution of precipitation with altitude. We used Kriging with External Drift (KED) interpolation scheme with elevation as a predictor to appraise spatiotemporal distribution of mean monthly, seasonal and annual precipitation for the period of 1998-2012. The KED-based annual precipitation estimates are verified by the corresponding basin-wide observed specific runoffs, which show good agreement. In contrast to earlier studies, our estimates reveal substantially higher precipitation in most of the sub-basins indicating two distinct rainfall maxima; 1st along southern and lower most slopes of Chenab, Jhelum, Indus main and Swat basins, and 2nd around north-west corner of Shyok basin in the central Karakoram. The study demonstrated that the selected gridded precipitation products covering this region are prone to significant errors. In terms of quantitative estimates, ERA-Interim is relatively close to the observations followed by WFDEI and TRMM, while APHRODITE gives highly underestimated precipitation estimates in the study area. Basin-wide seasonal and annual correction factors introduced for each gridded dataset can be useful for lumped hydrological modelling studies, while the estimated precipitation distribution can serve as a basis for bias correction of any gridded precipitation products for the study area. PMID

  10. Error Analysis of Satellite Precipitation-Driven Modeling of Complex Terrain Flood Events

    NASA Astrophysics Data System (ADS)

    Mei, Y.; Nikolopoulos, E. I.; Anagnostou, E. N.; Zoccatelli, D.; Borga, M., Sr.

    2015-12-01

    The error characteristics of satellite precipitation driven flood event simulations over mountainous basins are evaluated in this study for eight different global satellite products. A methodology is devised to match the observed records of the flood events with the corresponding satellite and reference rainfall and runoff simulations. The flood events are sorted according to flood type (i.e. rain flood and flash flood) and basin's antecedent conditions represented by the event's runoff-to-precipitation ratio. The satellite precipitation products and runoff simulations are evaluated based on systematic and random error metrics applied on the matched event pairs and basin scale event properties (i.e. cumulative volume, timing and shape). Overall satellite-driven event runoff exhibits better error metrics than the satellite precipitation. Better error metrics are also shown for the rain flood events relative to the flash flood events. The event timing and shape from satellite-derived precipitation agreed well with the reference; the cumulative volume is mostly underestimated. In terms of error propagation, the study shows dampening effect in both systematic and random error components of the satellite-driven runoff time series relative to the satellite-retrieved event precipitation. This error dampening effect is less pronounced for the flash flood events and the rain flood events with high runoff coefficients. This study provides for a first time flood event characteristics of the satellite precipitation error propagation in flood modeling, which has implications on the Global Precipitation Measurement application in mountain flood hydrology.

  11. Comparison of precipitation datasets over the tropical South American and African Continents.

    NASA Astrophysics Data System (ADS)

    Negron-Juarez, R. I.; Li, W.; Fu, R.; Fernandes, K.; Cardoso, A.

    2007-12-01

    Six rainfall datasets are compared over the Amazon basin, the Northeast Brazil and the Congo basin. These datasets include three gauge-only precipitation products from the Climatic Prediction Center (CPC), Global Precipitation Climatology Center (GPCC) and Brazilian Weather Forecast and Climate Studies Center (CLMNLS), and three combined gauge and satellite precipitation datasets from the CPC Merged Analysis of Precipitation (CMAP), Global Precipitation Climatology Project (GPCP) precipitation, and Tropical Rainfall Measuring Mission (TRMM) product. The spatial pattern of the annual precipitation is consistently represented by these data, despite of the differences in methods and periods of averaging. Quantitatively, the differences in annual precipitation among these datasets are 3% over our Amazon domain (0-15S, 50-70W), 17% over the Northeast Brazil (5-10S, 35-45W) and 12% the Congo domain (5N-10S, 15-30E). However the seasonal differences were. Over the Amazon domain, the rainfall variations are well correlated between CPC, GPCC, TRMM, GPCP and GPCC (>0.9) except for the northwestern Amazon. Over the Congo basin, the correlation between these rainfall datasets is generally below 0.7. The Empirical Orthogonal Functions analysis suggests large discrepancies in interannual and decadal variations of rainfall among these datasets, especially for the Congo basin and for the South American region after 1998.

  12. Thermodynamics of wax precipitation in petroleum mixtures

    SciTech Connect

    Firoozabadi, A.; Lira-Galeana, C.L.; Prausnitz, J.M.

    1995-12-01

    A thermodynamic framework is developed for calculating wax precipitation in petroleum mixtures over a wide temperature range. The framework assumes that the precipitated wax consists of several solid phases; each solid-phase is described as a pure component or pseudocomponent which does not mix with other solid phases. Liquid-phase properties are obtained from an equation of state. Calculated wax precipitation data are in excellent agreement with experimental results for binary and multicomponent hydrocarbon mixtures, including petroleum.

  13. Thermodynamics of wax precipitation in petroleum mixtures

    SciTech Connect

    Lira-Galeana, C.; Firoozabadi, A.; Prausnitz, J.M. |

    1996-01-01

    A thermodynamic framework is developed for calculating wax precipitation in petroleum mixtures over a wide temperature range. The framework uses the experimentally supported assumption that precipitated wax consists of several solid phases; each solid phase is described as a pure component or pseudocomponent that does not mix with other solid phases. Liquid-phase properties are obtained from an equation of state. Calculated wax-precipitation data are in excellent agreement with experimental results for binary and multicomponent hydrocarbon mixtures, including petroleum.

  14. High-resolution satellite-gauge merged precipitation climatologies of the Tropical Andes

    NASA Astrophysics Data System (ADS)

    Manz, Bastian; Buytaert, Wouter; Zulkafli, Zed; Lavado, Waldo; Willems, Bram; Robles, Luis Alberto; Rodríguez-Sánchez, Juan-Pablo

    2016-02-01

    Satellite precipitation products are becoming increasingly useful to complement rain gauge networks in regions where these are too sparse to capture spatial precipitation patterns, such as in the Tropical Andes. The Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (TPR) was active for 17 years (1998-2014) and has generated one of the longest single-sensor, high-resolution, and high-accuracy rainfall records. In this study, high-resolution (5 km) gridded mean monthly climatological precipitation is derived from the raw orbital TPR data (TRMM 2A25) and merged with 723 rain gauges using multiple satellite-gauge (S-G) merging approaches. The resulting precipitation products are evaluated by cross validation and catchment water balances (runoff ratios) for 50 catchments across the Tropical Andes. Results show that the TPR captures major synoptic and seasonal precipitation patterns and also accurately defines orographic gradients but underestimates absolute monthly rainfall rates. The S-G merged products presented in this study constitute an improved source of climatological rainfall data, outperforming the gridded TPR product as well as a rain gauge-only product based on ordinary Kriging. Among the S-G merging methods, performance of inverse distance interpolation of satellite-gauge residuals was similar to that of geostatistical methods, which were more sensitive to gauge network density. High uncertainty and low performance of the merged precipitation products predominantly affected regions with low and intermittent precipitation regimes (e.g., Peruvian Pacific coast) and is likely linked to the low TPR sampling frequency. All S-G merged products presented in this study are available in the public domain.

  15. Synthesis of high surface area ZnO powder by continuous precipitation

    SciTech Connect

    Boz, Ismail; Kaluza, Stefan; Boroglu, Mehtap Safak; Muhler, Martin

    2012-05-15

    Graphical abstract: High surface area ZnO powders are synthesized by a low temperature continuous precipitation under ultrasonication. Urea is used as precipitating agent so that no contamination of ZnO powder emanating from precipitating agent, such as, alkalis, is observed. pH and type of precursor greatly affects the surface area and other properties. In this manuscript, we report a very simple and effective continuous precipitation to synthesize high surface area ZnO powder. Highlights: Black-Right-Pointing-Pointer The synthesis of high surface area ZnO powder was achieved at 90 Degree-Sign C in a continuous precipitation unit. Black-Right-Pointing-Pointer Continuous precipitation unit was ultrasonicated to improve final product homogeneity. Black-Right-Pointing-Pointer Precipitation intermediate, hydrozincite, was led to high surface area ZnO powder. Black-Right-Pointing-Pointer The synthesized ZnO nanoparticles had a rather uniform mesoporous structure. -- Abstract: Synthesis of high surface area ZnO powder was achieved by continuous precipitation using zinc ions and urea at low temperature of 90 Degree-Sign C. The powder precipitated resulted in high-purity single-phase ZnO powder when calcined at 280 Degree-Sign C for 3 h in air. The solution pH and the precipitation duration strongly affected the surface area of the calcined ZnO powder. Detailed structural characterizations demonstrated that the synthesized ZnO powder were single crystalline with wurtzite hexagonal phase. The powdered samples precipitated by homogeneous precipitation crystallized directly to hydrozincite without any intermediate phase formation. The phase structures, morphologies and properties of the final ZnO powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering particle size analysis (DLS), and nitrogen physisorption in order to determine the specific surface area (BET) and the pore size distribution (BJH).

  16. Global Precipitation Measurement (GPM) Mission Data and Data Access

    NASA Astrophysics Data System (ADS)

    Stocker, Erich Franz

    2014-05-01

    If all goes as plans, the core satellite of the GPM mission will have launched on February 28, 2014 from the Tanegashima Space Center in Japan. The core satellite is the center of the GPM mission as it carries both an imagining radiometer with high frequency channels and a dual-frequency precipitation radar. In addition, the core satellite is at a 65 degree inclination so that it affords many opportunities of coincident measurements with the polar orbiting radiometers that form the GPM constellation. This allows the science team to intercalibrate the brightness temperature data retrieved from the constellation satellites by using the core satellite data as the reference satellite. This will ensure that GPM produces consistent mission brightness temperatures that should lead to consistent precipitation retrievals. The paper will also present the data production status as of the week before the conference. The precipitation community will, of course, be very interested in the data generated by the core satellite instruments as well as the intercalibrated brightness temperatures and precipitation retrievals from the partner constellation satellites. This paper will present the various data products, from the instrument count data through the monthly precipitation retrievals, produced as part of the mission. It will present the key parameters available in the products; provide information of the purpose of the various products; and provide some preliminary information about the weaknesses of the new products when compared to Tropical Rainfall Measuring Mission (TRMM) products. If the official public release of the first image has taken place before the conference, then the paper will provide some early examples of the data products. Near realtime (NRT) products from the core satellite radiometer and radar are available in both near-realtime and research mode. NRT precipitation retrievals will also be made from each of the partner radiometers. All these retrievals

  17. Propagating precipitation waves: experiments and modeling.

    PubMed

    Tinsley, Mark R; Collison, Darrell; Showalter, Kenneth

    2013-12-01

    Traveling precipitation waves, including counterrotating spiral waves, are observed in the precipitation reaction of AlCl3 with NaOH [Volford, A.; et al. Langmuir 2007, 23, 961 - 964]. Experimental and computational studies are carried out to characterize the wave behavior in cross-section configurations. A modified sol-coagulation model is developed that is based on models of Liesegang band and redissolution systems. The dynamics of the propagating waves is characterized in terms of growth and redissolution of a precipitation feature that travels through a migrating band of colloidal precipitate. PMID:24191642

  18. Global Precipitation Measurement (GPM) Mission Development Status

    NASA Technical Reports Server (NTRS)

    Azarbarzin, Ardeshir Art

    2011-01-01

    Mission Objective: (1) Improve scientific understanding of the global water cycle and fresh water availability (2) Improve the accuracy of precipitation forecasts (3) Provide frequent and complete sampling of the Earth s precipitation Mission Description (Class B, Category I): (1) Constellation of spacecraft provide global precipitation measurement coverage (2) NASA/JAXA Core spacecraft: Provides a microwave radiometer (GMI) and dual-frequency precipitation radar (DPR) to cross-calibrate entire constellation (3) 65 deg inclination, 400 km altitude (4) Launch July 2013 on HII-A (5) 3 year mission (5 year propellant) (6) Partner constellation spacecraft.

  19. Precipitation Across India's Ghats Mountains (IMERG)

    NASA Video Gallery

    Animation of precipitation rates across India and surrounding countries. Notice the heavy rains throughout the Ghats Mountain range which resulted in devastating landslides along India's west coast...

  20. Monitoring Precipitation from Space: targeting Hydrology Community?

    NASA Astrophysics Data System (ADS)

    Hong, Y.; Turk, J.

    2005-12-01

    During the past decades, advances in space, sensor and computer technology have made it possible to estimate precipitation nearly globally from a variety of observations in a relatively direct manner. The success of Tropical Precipitation Measuring Mission (TRMM) has been a significant advance for modern precipitation estimation algorithms to move toward daily quarter degree measurements, while the need for precipitation data at temporal-spatial resolutions compatible with hydrologic modeling has been emphasized by the end user: hydrology community. Can the future deployment of Global Precipitation Measurement constellation of low-altitude orbiting satellites (covering 90% of the global with a sampling interval of less than 3-hours), in conjunction with the existing suite of geostationary satellites, results in significant improvements in scale and accuracy of precipitation estimates suitable for hydrology applications? This presentation will review the current state of satellite-derived precipitation estimation and demonstrate the early results and primary barriers to full global high-resolution precipitation coverage. An attempt to facilitate the communication between data producers and users will be discussed by developing an 'end-to-end' uncertainty propagation analysis framework to quantify both the precipitation estimation error structure and the error influence on hydrological modeling.