Estimating riparian and agricultural evapotranspiration by reference crop evapotranspiration and MODIS Enhanced Vegetation Index

USGS Publications Warehouse

Nagler, Pamela L.; Glenn, Edward P.; Nguyen, Uyen; Scott, Russell; Doody, Tania

2013-01-01

Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa) based on the Enhanced Vegetation Index (EVI) from the Moderate Resolution Imaging Spectrometer (MODIS) sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo). The algorithm was calibrated with five years of ETa data from three eddy covariance flux towers set in riparian plant associations on the upper San Pedro River, Arizona, supplemented with ETa data for alfalfa and cotton from the literature. The algorithm was based on an equation of the form ETa = ETo [a(1 − e−bEVI) − c], where the term (1 − e−bEVI) is derived from the Beer-Lambert Law to express light absorption by a canopy, with EVI replacing leaf area index as an estimate of the density of light-absorbing units. The resulting algorithm capably predicted ETa across riparian plants and crops (r2 = 0.73). It was then tested against water balance data for five irrigation districts and flux tower data for two riparian zones for which season-long or multi-year ETa data were available. Predictions were within 10% of measured results in each case, with a non-significant (P = 0.89) difference between mean measured and modeled ETa of 5.4% over all validation sites. Validation and calibration data sets were combined to present a final predictive equation for application across crops and riparian plant associations for monitoring individual irrigation districts or for conducting global water use assessments of mixed agricultural and riparian biomes.

[Applicability of established drought index in Huang-Huai-Hai region based on actual evapotranspiration.

PubMed

Wang, Ying; Wu, Rong Jun; Guo, Zhao Bing

2016-05-01

Based on the modeled products of actual evapotranspiration with NOAH land surface model, the temporal and spatial variations of actual evapotranspiration were analyzed for the Huang-Huai-Hai region in 2002-2010. In the meantime, the agricultural drought index, namely, drought severity index (DSI) was constructed, incorporated with products of MOD17 potential evapotranspiration and MOD13 NDVI. Furthermore, the applicability of established DSI in this region in the whole year of 2002 was investigated based on the Palmer drought severity index (PDSI), the yield reduction rate of winter wheat, and drought severity data. The results showed that the annual average actual evapotranspiration within the survey region increased from the northwest to the southeast, with the maximum of 800-900 mm in the southeast and the minimum less than 300 mm in the northwest. The DSI and PDSI had positive correlation (R 2 =0.61) and high concordance in change trend. They all got the low point (-0.61 and -1.33) in 2002 and reached the peak (0.81 and 0.92) in 2003. The correlation between DSI and yield reduction rate of winter wheat (R 2 =0.43) was more significant than that between PDSI and yield reduction rate of winter wheat (R 2 =0.06). So, the DSI reflected a high spatial resolution of drought pattern and could reflect the region agricultural drought severity and intensity more accurately.

Predicting water suppy and actual evapotranspiration of street trees

NASA Astrophysics Data System (ADS)

Wessolek, Gerd; Heiner, Moreen; Trinks, Steffen

2017-04-01

It's well known that street trees cool air temperature in summer-time by transpiration and shading and also reduce runoff. However, it's difficult to analyse if trees have water shortage or not. This contribution focus on predicting water supply, actual evapotranspiration, and runoff by using easily available climate data (precipiation, potential evapotranspiration) and site characteristics (water retention, space, sealing degree, groundwater depth). These parameter were used as input data for Hydro-Pedotransfer-Functions (HPTFs) allowing the estimation of the annual water budget. Results give statements on water supply of trees, drought stress, and additional water demand by irrigation. Procedure also analyse, to which extent the surrounding partly sealed surfaces deliver water to the trees. Four representative street canyons of Berlin City were analysed and evaluated within in training program for M.A. students of „Urban Eco-system Science" at the Technische Universität Berlin.

[Spatiotemporal variation characteristics and related affecting factors of actual evapotranspiration in the Hun-Taizi River Basin, Northeast China].

PubMed

Feng, Xue; Cai, Yan-Cong; Guan, De-Xin; Jin, Chang-Jie; Wang, An-Zhi; Wu, Jia-Bing; Yuan, Feng-Hui

2014-10-01

Based on the meteorological and hydrological data from 1970 to 2006, the advection-aridity (AA) model with calibrated parameters was used to calculate evapotranspiration in the Hun-Taizi River Basin in Northeast China. The original parameter of the AA model was tuned according to the water balance method and then four subbasins were selected to validate. Spatiotemporal variation characteristics of evapotranspiration and related affecting factors were analyzed using the methods of linear trend analysis, moving average, kriging interpolation and sensitivity analysis. The results showed that the empirical parameter value of 0.75 of AA model was suitable for the Hun-Taizi River Basin with an error of 11.4%. In the Hun-Taizi River Basin, the average annual actual evapotranspiration was 347.4 mm, which had a slightly upward trend with a rate of 1.58 mm · (10 a(-1)), but did not change significantly. It also indicated that the annual actual evapotranspiration presented a single-peaked pattern and its peak value occurred in July; the evapotranspiration in summer was higher than in spring and autumn, and it was the smallest in winter. The annual average evapotranspiration showed a decreasing trend from the northwest to the southeast in the Hun-Taizi River Basin from 1970 to 2006 with minor differences. Net radiation was largely responsible for the change of actual evapotranspiration in the Hun-Taizi River Basin.

Testing two temporal upscaling schemes for the estimation of the time variability of the actual evapotranspiration

NASA Astrophysics Data System (ADS)

Maltese, A.; Capodici, F.; Ciraolo, G.; La Loggia, G.

2015-10-01

Temporal availability of grapes actual evapotranspiration is an emerging issue since vineyards farms are more and more converted from rainfed to irrigated agricultural systems. The manuscript aims to verify the accuracy of the actual evapotranspiration retrieval coupling a single source energy balance approach and two different temporal upscaling schemes. The first scheme tests the temporal upscaling of the main input variables, namely the NDVI, albedo and LST; the second scheme tests the temporal upscaling of the energy balance output, the actual evapotranspiration. The temporal upscaling schemes were implemented on: i) airborne remote sensing data acquired monthly during a whole irrigation season over a Sicilian vineyard; ii) low resolution MODIS products released daily or weekly; iii) meteorological data acquired by standard gauge stations. Daily MODIS LST products (MOD11A1) were disaggregated using the DisTrad model, 8-days black and white sky albedo products (MCD43A) allowed modeling the total albedo, and 8-days NDVI products (MOD13Q1) were modeled using the Fisher approach. Results were validated both in time and space. The temporal validation was carried out using the actual evapotranspiration measured in situ using data collected by a flux tower through the eddy covariance technique. The spatial validation involved airborne images acquired at different times from June to September 2008. Results aim to test whether the upscaling of the energy balance input or output data performed better.

Evapotranspiration Calculations for an Alpine Marsh Meadow Site in Three-river Headwater Region

NASA Astrophysics Data System (ADS)

Zhou, B.; Xiao, H.

2016-12-01

Daily radiation and meteorological data were collected at an alpine marsh meadow site in the Three-river Headwater Region(THR). Use them to assess radiation models determined after comparing the performance between Zuo model and the model recommend by FAO56P-M.Four methods, FAO56P-M, Priestley-Taylor, Hargreaves, and Makkink methods were applied to determine daily reference evapotranspiration( ETr) for the growing season and built the empirical models for estimating daily actual evapotranspiration ETa between ETr derived from the four methods and evapotranspiration derived from Bowen Ratio method on alpine marsh meadow in this region. After comparing the performance of four empirical models by RMSE, MAE and AI, it showed these models all can get the better estimated daily ETaon alpine marsh meadow in this region, and the best performance of the FAO56 P-M, Makkink empirical model were better than Priestley-Taylor and Hargreaves model.

A coupled remote sensing and simplified surface energy balance approach to estimate actual evapotranspiration from irrigated fields

USGS Publications Warehouse

Senay, G.B.; Budde, Michael; Verdin, J.P.; Melesse, Assefa M.

2007-01-01

Accurate crop performance monitoring and production estimation are critical for timely assessment of the food balance of several countries in the world. Since 2001, the Famine Early Warning Systems Network (FEWS NET) has been monitoring crop performance and relative production using satellite-derived data and simulation models in Africa, Central America, and Afghanistan where ground-based monitoring is limited because of a scarcity of weather stations. The commonly used crop monitoring models are based on a crop water-balance algorithm with inputs from satellite-derived rainfall estimates. These models are useful to monitor rainfed agriculture, but they are ineffective for irrigated areas. This study focused on Afghanistan, where over 80 percent of agricultural production comes from irrigated lands. We developed and implemented a Simplified Surface Energy Balance (SSEB) model to monitor and assess the performance of irrigated agriculture in Afghanistan using a combination of 1-km thermal data and 250m Normalized Difference Vegetation Index (NDVI) data, both from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. We estimated seasonal actual evapotranspiration (ETa) over a period of six years (2000-2005) for two major irrigated river basins in Afghanistan, the Kabul and the Helmand, by analyzing up to 19 cloud-free thermal and NDVI images from each year. These seasonal ETa estimates were used as relative indicators of year-to-year production magnitude differences. The temporal water-use pattern of the two irrigated basins was indicative of the cropping patterns specific to each region. Our results were comparable to field reports and to estimates based on watershed-wide crop water-balance model results. For example, both methods found that the 2003 seasonal ETa was the highest of all six years. The method also captured water management scenarios where a unique year-to-year variability was identified in addition to water-use differences between

A Coupled Remote Sensing and Simplified Surface Energy Balance Approach to Estimate Actual Evapotranspiration from Irrigated Fields

PubMed Central

Senay, Gabriel B.; Budde, Michael; Verdin, James P.; Melesse, Assefa M.

2007-01-01

Accurate crop performance monitoring and production estimation are critical for timely assessment of the food balance of several countries in the world. Since 2001, the Famine Early Warning Systems Network (FEWS NET) has been monitoring crop performance and relative production using satellite-derived data and simulation models in Africa, Central America, and Afghanistan where ground-based monitoring is limited because of a scarcity of weather stations. The commonly used crop monitoring models are based on a crop water-balance algorithm with inputs from satellite-derived rainfall estimates. These models are useful to monitor rainfed agriculture, but they are ineffective for irrigated areas. This study focused on Afghanistan, where over 80 percent of agricultural production comes from irrigated lands. We developed and implemented a Simplified Surface Energy Balance (SSEB) model to monitor and assess the performance of irrigated agriculture in Afghanistan using a combination of 1-km thermal data and 250-m Normalized Difference Vegetation Index (NDVI) data, both from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. We estimated seasonal actual evapotranspiration (ETa) over a period of six years (2000-2005) for two major irrigated river basins in Afghanistan, the Kabul and the Helmand, by analyzing up to 19 cloud-free thermal and NDVI images from each year. These seasonal ETa estimates were used as relative indicators of year-to-year production magnitude differences. The temporal water-use pattern of the two irrigated basins was indicative of the cropping patterns specific to each region. Our results were comparable to field reports and to estimates based on watershed-wide crop water-balance model results. For example, both methods found that the 2003 seasonal ETa was the highest of all six years. The method also captured water management scenarios where a unique year-to-year variability was identified in addition to water-use differences between

Vegetation index methods for estimating evapotranspiration by remote sensing

USGS Publications Warehouse

Glenn, Edward P.; Nagler, Pamela L.; Huete, Alfredo R.

2010-01-01

Evapotranspiration (ET) is the largest term after precipitation in terrestrial water budgets. Accurate estimates of ET are needed for numerous agricultural and natural resource management tasks and to project changes in hydrological cycles due to potential climate change. We explore recent methods that combine vegetation indices (VI) from satellites with ground measurements of actual ET (ETa) and meteorological data to project ETa over a wide range of biome types and scales of measurement, from local to global estimates. The majority of these use time-series imagery from the Moderate Resolution Imaging Spectrometer on the Terra satellite to project ET over seasons and years. The review explores the theoretical basis for the methods, the types of ancillary data needed, and their accuracy and limitations. Coefficients of determination between modeled ETa and measured ETa are in the range of 0.45–0.95, and root mean square errors are in the range of 10–30% of mean ETa values across biomes, similar to methods that use thermal infrared bands to estimate ETa and within the range of accuracy of the ground measurements by which they are calibrated or validated. The advent of frequent-return satellites such as Terra and planed replacement platforms, and the increasing number of moisture and carbon flux tower sites over the globe, have made these methods feasible. Examples of operational algorithms for ET in agricultural and natural ecosystems are presented. The goal of the review is to enable potential end-users from different disciplines to adapt these methods to new applications that require spatially-distributed ET estimates.

Projection of actual evapotranspiration using the COSMO-CLM regional climate model under global warming scenarios of 1.5 °C and 2.0 °C in the Tarim River basin, China

NASA Astrophysics Data System (ADS)

Su, Buda; Jian, Dongnan; Li, Xiucang; Wang, Yanjun; Wang, Anqian; Wen, Shanshan; Tao, Hui; Hartmann, Heike

2017-11-01

Actual evapotranspiration (ETa) is an important component of the water cycle. The goals for limiting global warming to below 2.0 °C above pre-industrial levels and aspiring to 1.5 °C were negotiated in the Paris Agreement in 2015. In this study, outputs from the regional climate model COSMO-CLM (CCLM) for the Tarim River basin (TRB) were used to calculate ETa with an advection-aridity model, and changes in ETa under global warming scenarios of 1.5 °C (2020 to 2039) and 2.0 °C (2040 to 2059) were analyzed. Comparison of warming at the global and regional scale showed that regional 1.5 °C warming would occur later than the global average, while regional 2.0 °C warming would occur earlier than the global average. For global warming of 1.5 °C, the average ETa in the TRB is about 222.7 mm annually, which represents an increase of 6.9 mm relative to the reference period (1986-2005), with obvious increases projected for spring and summer. The greatest increases in ETa were projected for the northeast and southwest. The increment in the annual ETa across the TRB considering a warming of 1.5 °C was 4.3 mm less than that for a warming of 2.0 °C, and the reduction between the two levels of warming was most pronounced in the summer, when ETa was 3.4 mm smaller. The reduction in the increment of annual ETa for warming of 1.5 °C relative to warming of 2.0 °C was most pronounced in the southwest and northeast, where it was projected to be 8.2 mm and 9.3 mm smaller, respectively. It is suggested that the higher ETa under a warming of 2.0 °C mainly results from an increase in the sunshine duration (net radiation) in the southwestern basin and an increase in precipitation in the northeastern basin. Vapor is removed from the limited surface water supplies by ETa. The results of this study are therefore particularly relevant for water resource planning in the TRB.

Evaluating the role of evapotranspiration remote sensing data in improving hydrological modeling predictability

NASA Astrophysics Data System (ADS)

Herman, Matthew R.; Nejadhashemi, A. Pouyan; Abouali, Mohammad; Hernandez-Suarez, Juan Sebastian; Daneshvar, Fariborz; Zhang, Zhen; Anderson, Martha C.; Sadeghi, Ali M.; Hain, Christopher R.; Sharifi, Amirreza

2018-01-01

As the global demands for the use of freshwater resources continues to rise, it has become increasingly important to insure the sustainability of this resources. This is accomplished through the use of management strategies that often utilize monitoring and the use of hydrological models. However, monitoring at large scales is not feasible and therefore model applications are becoming challenging, especially when spatially distributed datasets, such as evapotranspiration, are needed to understand the model performances. Due to these limitations, most of the hydrological models are only calibrated for data obtained from site/point observations, such as streamflow. Therefore, the main focus of this paper is to examine whether the incorporation of remotely sensed and spatially distributed datasets can improve the overall performance of the model. In this study, actual evapotranspiration (ETa) data was obtained from the two different sets of satellite based remote sensing data. One dataset estimates ETa based on the Simplified Surface Energy Balance (SSEBop) model while the other one estimates ETa based on the Atmosphere-Land Exchange Inverse (ALEXI) model. The hydrological model used in this study is the Soil and Water Assessment Tool (SWAT), which was calibrated against spatially distributed ETa and single point streamflow records for the Honeyoey Creek-Pine Creek Watershed, located in Michigan, USA. Two different techniques, multi-variable and genetic algorithm, were used to calibrate the SWAT model. Using the aforementioned datasets, the performance of the hydrological model in estimating ETa was improved using both calibration techniques by achieving Nash-Sutcliffe efficiency (NSE) values >0.5 (0.73-0.85), percent bias (PBIAS) values within ±25% (±21.73%), and root mean squared error - observations standard deviation ratio (RSR) values <0.7 (0.39-0.52). However, the genetic algorithm technique was more effective with the ETa calibration while significantly

Actual Evapotranspiration (AET) and tree species richness in the eastern U.S.A.

Treesearch

Weihong Fan; Richard H. Waring

2009-01-01

Although many studies confirm that competition and disturbance play important roles in determining tree diversity locally, climatic constraints become increasingly important at broader geographic scales. We evaluate the extent that annual actual evapotranspiration (AET) might account for observed variation in tree diversity across the entire eastern U.S. and within 24...

Evaluation of the relation between evapotranspiration and normalized difference vegetation index for downscaling the simplified surface energy balance model

USGS Publications Warehouse

Haynes, Jonathan V.; Senay, Gabriel B.

2012-01-01

The Simplified Surface Energy Balance (SSEB) model uses satellite imagery to estimate actual evapotranspiration (ETa) at 1-kilometer resolution. SSEB ETa is useful for estimating irrigation water use; however, resolution limitations restrict its use to regional scale applications. The U.S. Geological Survey investigated the downscaling potential of SSEB ETa from 1 kilometer to 250 meters by correlating ETa with the Normalized Difference Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectroradiometer instrument (MODIS). Correlations were studied in three arid to semiarid irrigated landscapes of the Western United States (Escalante Valley near Enterprise, Utah; Palo Verde Valley near Blythe, California; and part of the Columbia Plateau near Quincy, Washington) during several periods from 2002 to 2008. Irrigation season ETa-NDVI correlations were lower than expected, ranging from R2 of 0.20 to 0.61 because of an eastward 2–3 kilometer shift in ETadata. The shift is due to a similar shift identified in the land-surface temperature (LST) data from the MODIS Terra satellite, which is used in the SSEB model. Further study is needed to delineate the Terra LST shift, its effect on SSEB ETa, and the relation between ETa and NDVI.

Feedback Loop of Data Infilling Using Model Result of Actual Evapotranspiration from Satellites and Hydrological Model

NASA Astrophysics Data System (ADS)

Murdi Hartanto, Isnaeni; Alexandridis, Thomas K.; van Andel, Schalk Jan; Solomatine, Dimitri

2014-05-01

Using satellite data in a hydrological model has long been occurring in modelling of hydrological processes, as a source of low cost regular data. The methods range from using satellite products as direct input, model validation, and data assimilation. However, the satellite data frequently face the missing value problem, whether due to the cloud cover or the limited temporal coverage. The problem could seriously affect its usefulness in hydrological model, especially if the model uses it as direct input, so data infilling becomes one of the important parts in the whole modelling exercise. In this research, actual evapotranspiration product from satellite is directly used as input into a spatially distributed hydrological model, and validated by comparing the catchment's end discharge with measured data. The instantaneous actual evapotranspiration is estimated from MODIS satellite images using a variation of the energy balance model for land (SEBAL). The eight-day cumulative actual evapotranspiration is then obtained by a temporal integration that uses the reference evapotranspiration calculated from meteorological data [1]. However, the above method cannot fill in a cell if the cell is constantly having no-data value during the eight-day periods. The hydrological model requires full set of data without no-data cells, hence, the no-data cells in the satellite's evapotranspiration map need to be filled in. In order to fills the no-data cells, an output of hydrological model is used. The hydrological model is firstly run with reference evapotranspiration as input to calculate discharge and actual evapotranspiration. The no-data cells in the eight-day cumulative map from the satellite are then filled in with the output of the first run of hydrological model. The final data is then used as input in a hydrological model to calculate discharge, thus creating a loop. The method is applied in the case study of Rijnland, the Netherlands where in the winter, cloud cover is

Evapotranspiration partitioning, stomatal conductance, and components of the water balance: A special case of a desert ecosystem in China

NASA Astrophysics Data System (ADS)

Zhao, Wenzhi; Liu, Bing; Chang, Xuexiang; Yang, Qiyue; Yang, Yuting; Liu, Zhiling; Cleverly, James; Eamus, Derek

2016-07-01

Partitioning evapotranspiration (ET) into its components reveals details of the processes that underlie ecosystem hydrologic budgets and their feedback to the water cycle. We measured rates of actual evapotranspiration (ETa), canopy transpiration (Tc), soil evaporation (Eg), canopy-intercepted precipitation (EI), and patterns of stomatal conductance of the desert shrub Calligonum mongolicum in northern China to determine the water balance of this ecosystem. The ETa was 251 ± 8 mm during the growing period, while EI, Tc, and Eg accounted for 3.2%, 63.9%, and 31.3%, respectively, of total water use (256 ± 4 mm) during the growing period. In this unique ecosystem, groundwater was the main water source for plant transpiration and soil evaporation, Tc and exceeded 60% of the total annual water used by desert plants. ET was not sensitive to air temperature in this unique desert ecosystem. Partitioning ET into its components improves our understanding of the mechanisms that underlie adaptation of desert shrubs, especially the role of stomatal regulation of Tc as a determinant of ecosystem water balance.

Assessing actual evapotranspiration via surface energy balance aiming to optimize water and energy consumption in large scale pressurized irrigation systems

NASA Astrophysics Data System (ADS)

Awada, H.; Ciraolo, G.; Maltese, A.; Moreno Hidalgo, M. A.; Provenzano, G.; Còrcoles, J. I.

2017-10-01

Satellite imagery provides a dependable basis for computational models that aimed to determine actual evapotranspiration (ET) by surface energy balance. Satellite-based models enables quantifying ET over large areas for a wide range of applications, such as monitoring water distribution, managing irrigation and assessing irrigation systems' performance. With the aim to evaluate the energy and water consumption of a large scale on-turn pressurized irrigation system in the district of Aguas Nuevas, Albacete, Spain, the satellite-based image-processing model SEBAL was used for calculating actual ET. The model has been applied to quantify instantaneous, daily, and seasonal actual ET over high- resolution Landsat images for the peak water demand season (May to September) and for the years 2006 - 2008. The model provided a direct estimation of the distribution of main energy fluxes, at the instant when the satellite overpassed over each field of the district. The image acquisition day Evapotranspiration (ET24) was obtained from instantaneous values by assuming a constant evaporative fraction (Λ) for the entire day of acquisition; then, monthly and seasonal ET were estimated from the daily evapotranspiration (ETdaily) assuming that ET24 varies in proportion to reference ET (ETr) at the meteorological station, thus accounting for day to day variation in meteorological forcing. The comparison between the hydrants water consumption and the actual evapotranspiration, considering an irrigation efficiency of 85%, showed that a considerable amount of water and energy can be saved at district level.

Simple models to predict grassland ecosystem C exchange and actual evapotranspiration using NDVI and environmental variables

USDA-ARS?s Scientific Manuscript database

Semiarid grasslands contribute significantly to net terrestrial carbon flux as plant productivity and heterotrophic respiration in these moisture-limited systems are correlated with metrics related to water availability (e.g., precipitation, Actual EvapoTranspiration or AET). These variables are als...

Bulk canopy resistance: Modeling for the estimation of actual evapotranspiration of maize

NASA Astrophysics Data System (ADS)

Gharsallah, O.; Corbari, C.; Mancini, M.; Rana, G.

2009-04-01

Due to the scarcity of water resources, the correct evaluation of water losses by the crops as evapotranspiration (ET) is very important in irrigation management. This work presents a model for estimating actual evapotranspiration on hourly and daily scales of maize crop grown in well water condition in the Lombardia Region (North Italy). The maize is a difficult crop to model from the soil-canopy-atmosphere point of view, due to its very complex architecture and big height. The present ET model is based on the Penman-Monteith equation using Katerji and Perrier approach for modelling the variable canopy resistance value (rc). In fact rc is a primary factor in the evapotranspiration process and needs to be accurately estimated. Furthermore, ET also has an aerodynamic component, hence it depends on multiple factors such as meteorological variables and crop water condition. The proposed approach appears through a linear model in which rc depends on climate variables and aerodynamic resistance [rc/ra = f(r*/ra)] where ra is the aerodynamic resistance, function of wind speed and crop height, and r* is called "critical" or "climatic" resistance. Here, under humid climate, the model has been applied with good results at both hourly and daily scales. In this study, the reached good accuracy shows that the model worked well and are clearly more accurate than those obtained by using the more diffuse and known standard FAO 56 method for well watered and stressed crops.

Comparison of two recent models for estimating actual evapotranspiration using only regularly recorded data

NASA Astrophysics Data System (ADS)

Ali, M. F.; Mawdsley, J. A.

1987-09-01

An advection-aridity model for estimating actual evapotranspiration ET is tested with over 700 days of lysimeter evapotranspiration and meteorological data from barley, turf and rye-grass from three sites in the U.K. The performance of the model is also compared with the API model . It is observed from the test that the advection-aridity model overestimates nonpotential ET and tends to underestimate potential ET, but when tested with potential and nonpotential data together, the tendencies appear to cancel each other. On a daily basis the performance level of this model is found to be of the same order as the API model: correlation coefficients were obtained between the model estimates and lysimeter data of 0.62 and 0.68 respectively. For periods greater than one day, generally the performance of the models are improved. Proposed by Mawdsley and Ali (1979)

Modeling landscape evapotranspiration by integrating land surface phenology and a water balance algorithm

USGS Publications Warehouse

Senay, Gabriel B.

2008-01-01

The main objective of this study is to present an improved modeling technique called Vegetation ET (VegET) that integrates commonly used water balance algorithms with remotely sensed Land Surface Phenology (LSP) parameter to conduct operational vegetation water balance modeling of rainfed systems at the LSP’s spatial scale using readily available global data sets. Evaluation of the VegET model was conducted using Flux Tower data and two-year simulation for the conterminous US. The VegET model is capable of estimating actual evapotranspiration (ETa) of rainfed crops and other vegetation types at the spatial resolution of the LSP on a daily basis, replacing the need to estimate crop- and region-specific crop coefficients.

Estimation of actual evapotranspiration in the Nagqu river basin of the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Zou, Mijun; Zhong, Lei; Ma, Yaoming; Hu, Yuanyuan; Feng, Lu

2018-05-01

As a critical component of the energy and water cycle, terrestrial actual evapotranspiration (ET) can be influenced by many factors. This study was mainly devoted to providing accurate and continuous estimations of actual ET for the Tibetan Plateau (TP) and analyzing the effects of its impact factors. In this study, summer observational data from the Coordinated Enhanced Observing Period (CEOP) Asia-Australia Monsoon Project (CAMP) on the Tibetan Plateau (CAMP/Tibet) for 2003 to 2004 was selected to determine actual ET and investigate its relationship with energy, hydrological, and dynamical parameters. Multiple-layer air temperature, relative humidity, net radiation flux, wind speed, precipitation, and soil moisture were used to estimate actual ET. The regression model simulation results were validated with independent data retrieved using the combinatory method. The results suggested that significant correlations exist between actual ET and hydro-meteorological parameters in the surface layer of the Nagqu river basin, among which the most important factors are energy-related elements (net radiation flux and air temperature). The results also suggested that how ET is eventually affected by precipitation and two-layer wind speed difference depends on whether their positive or negative feedback processes have a more important role. The multivariate linear regression method provided reliable estimations of actual ET; thus, 6-parameter simplified schemes and 14-parameter regular schemes were established.

Estimation of Actual Evapotranspiration by Remote Sensing: Application in Thessaly Plain, Greece

PubMed Central

Tsouni, Alexia; Kontoes, Charalabos; Koutsoyiannis, Demetris; Elias, Panagiotis; Mamassis, Nikos

2008-01-01

Remote sensing can assist in improving the estimation of the geographical distribution of evapotranspiration, and consequently water demand in large cultivated areas for irrigation purposes and sustainable water resources management. In the direction of these objectives, the daily actual evapotranspiration was calculated in this study during the summer season of 2001 over the Thessaly plain in Greece, a wide irrigated area of great agricultural importance. Three different methods were adapted and applied: the remote-sensing methods by Granger (2000) and Carlson and Buffum (1989) that use satellite data in conjunction with ground meteorological measurements and an adapted FAO (Food and Agriculture Organisation) Penman-Monteith method (Allen at al. 1998), which was selected to be the reference method. The satellite data were used in conjunction with ground data collected on the three closest meteorological stations. All three methods, exploit visible channels 1 and 2 and infrared channels 4 and 5 of NOAA-AVHRR (National Oceanic and Atmospheric Administration - Advanced Very High Resolution Radiometer) sensor images to calculate albedo and NDVI (Normalised Difference Vegetation Index), as well as surface temperatures. The FAO Penman-Monteith and the Granger method have used exclusively NOAA-15 satellite images to obtain mean surface temperatures. For the Carlson-Buffum method a combination of NOAA-14 and NOAA-15 satellite images was used, since the average rate of surface temperature rise during the morning was required. The resulting estimations show that both the Carlson-Buffum and Granger methods follow in general the variations of the reference FAO Penman-Monteith method. Both methods have potential for estimating the spatial distribution of evapotranspiration, whereby the degree of the relative agreement with the reference FAO Penman-Monteith method depends on the crop growth stage. In particular, the Carlson-Buffum method performed better during the first half

Estimation of Actual Evapotranspiration by Remote Sensing: Application in Thessaly Plain, Greece.

PubMed

Tsouni, Alexia; Kontoes, Charalabos; Koutsoyiannis, Demetris; Elias, Panagiotis; Mamassis, Nikos

2008-06-01

Remote sensing can assist in improving the estimation of the geographical distribution of evapotranspiration, and consequently water demand in large cultivated areas for irrigation purposes and sustainable water resources management. In the direction of these objectives, the daily actual evapotranspiration was calculated in this study during the summer season of 2001 over the Thessaly plain in Greece, a wide irrigated area of great agricultural importance. Three different methods were adapted and applied: the remotesensing methods by Granger (2000) and Carlson and Buffum (1989) that use satellite data in conjunction with ground meteorological measurements and an adapted FAO (Food and Agriculture Organisation) Penman-Monteith method (Allen at al. 1998), which was selected to be the reference method. The satellite data were used in conjunction with ground data collected on the three closest meteorological stations. All three methods, exploit visible channels 1 and 2 and infrared channels 4 and 5 of NOAA-AVHRR (National Oceanic and Atmospheric Administration - Advanced Very High Resolution Radiometer) sensor images to calculate albedo and NDVI (Normalised Difference Vegetation Index), as well as surface temperatures. The FAO Penman-Monteith and the Granger method have used exclusively NOAA-15 satellite images to obtain mean surface temperatures. For the Carlson-Buffum method a combination of NOAA-14 and ΝΟΑΑ-15 satellite images was used, since the average rate of surface temperature rise during the morning was required. The resulting estimations show that both the Carlson-Buffum and Granger methods follow in general the variations of the reference FAO Penman-Monteith method. Both methods have potential for estimating the spatial distribution of evapotranspiration, whereby the degree of the relative agreement with the reference FAO Penman-Monteith method depends on the crop growth stage. In particular, the Carlson- Buffum method performed better during the first

Variation of Vegetation Ecological Water Consumption and Its Response to Vegetation Coverage Changes in the Rocky Desertification Areas in South China

PubMed Central

Zhou, Jinxing; Guo, Hongyan; Cui, Ming; Liu, Yuguo; Ning, Like; Tang, Fukai

2016-01-01

Over the past several decades, rocky desertification has led to severe ecological problems in karst areas in South China. After a rocky desertification treatment project was completed, the vegetation coverage changed greatly and, consequently, increased the ecology water consumption (approximately equal to the actual evapotranspiration) of the regional vegetation. Thus, it intensified the regional water stresses. This study explored the changes in the actual evapotranspiration (ETa) response to the vegetation coverage changes in the rocky desertification areas in South China based on the precipitation (P), potential evapotranspiration (ETp) and NDVI (the normalized difference vegetation index) datasets. The revised Bagrov model was used to simulate the actual evapotranspiration changes with the supposed increasing NDVI. The results indicated that the average NDVI value was lower when the rocky desertification was more severe. The ETa, evapotranspiration efficiency (ETa/ETp) and potential humidity (P/ETp) generally increased with the increasing NDVI. The sensitivity of the ETa response to vegetation coverage changes varied due to different precipitation conditions and different rocky desertification severities. The ETa was more sensitive under drought conditions. When a drought occurred, the ETa exhibited an average increase of 40~60 mm with the NDVI increasing of 0.1 in the rocky desertification areas. Among the 5 different severity categories of rocky desertification, the ETa values’ responses to NDVI changes were less sensitive in the severe rocky desertification areas but more sensitive in the extremely and potential rocky desertification areas. For example, with the NDVI increasing of 0.025, 0.05, 0.075, and 0.1, the corresponding ETa changes increased by an average of 2.64 mm, 10.62 mm, 19.19 mm, and 27.58 mm, respectively, in severe rocky desertification areas but by 4.94 mm, 14.99 mm, 26.80, and 37.13 mm, respectively, in extremely severe rocky

Variation of Vegetation Ecological Water Consumption and Its Response to Vegetation Coverage Changes in the Rocky Desertification Areas in South China.

PubMed

Wan, Long; Tong, Jing; Zhou, Jinxing; Guo, Hongyan; Cui, Ming; Liu, Yuguo; Ning, Like; Tang, Fukai

2016-01-01

Over the past several decades, rocky desertification has led to severe ecological problems in karst areas in South China. After a rocky desertification treatment project was completed, the vegetation coverage changed greatly and, consequently, increased the ecology water consumption (approximately equal to the actual evapotranspiration) of the regional vegetation. Thus, it intensified the regional water stresses. This study explored the changes in the actual evapotranspiration (ETa) response to the vegetation coverage changes in the rocky desertification areas in South China based on the precipitation (P), potential evapotranspiration (ETp) and NDVI (the normalized difference vegetation index) datasets. The revised Bagrov model was used to simulate the actual evapotranspiration changes with the supposed increasing NDVI. The results indicated that the average NDVI value was lower when the rocky desertification was more severe. The ETa, evapotranspiration efficiency (ETa/ETp) and potential humidity (P/ETp) generally increased with the increasing NDVI. The sensitivity of the ETa response to vegetation coverage changes varied due to different precipitation conditions and different rocky desertification severities. The ETa was more sensitive under drought conditions. When a drought occurred, the ETa exhibited an average increase of 40~60 mm with the NDVI increasing of 0.1 in the rocky desertification areas. Among the 5 different severity categories of rocky desertification, the ETa values' responses to NDVI changes were less sensitive in the severe rocky desertification areas but more sensitive in the extremely and potential rocky desertification areas. For example, with the NDVI increasing of 0.025, 0.05, 0.075, and 0.1, the corresponding ETa changes increased by an average of 2.64 mm, 10.62 mm, 19.19 mm, and 27.58 mm, respectively, in severe rocky desertification areas but by 4.94 mm, 14.99 mm, 26.80, and 37.13 mm, respectively, in extremely severe rocky

Operational actual wetland evapotranspiration estimation for the Everglades using MODIS imagery

NASA Astrophysics Data System (ADS)

Melesse, Assefa; Cereon, Cristobal

2014-05-01

Wetlands are one of the most important ecosystems with varied functions and structures. Humans have drained wetlands and altered the structure and functions of wetlands for various uses. Wetland restoration efforts require assessment of the level of ecohydrological restoration for the intended functions. Among the various indicators of success in wetland restoration, achieving the desired water level (hydrology) is the most important, faster to achieve and easier to monitor than the establishment of the hydric soils and wetland vegetation. Monitoring wetland hydrology using remote sensing based evapotranspiration (ET) is a useful tool and approach since point measurements for understanding the temporal (before and after restoration) and spatial (impacted and restored) parts of the wetland are not effective for large areas. Evapotranspiration accounts over 80% of the water budget of the wetlands necessitating the need for spatiotemporal monitoring of ET flux. A study employing remotely sensed data from Moderate Resolution Imaging Spectroradiometer (MODIS) and modeling tools was conducted for a weekly spatial estimation of Everglades ET. Weekly surface temperature data were generated from the MODIS thermal band and evaporative fraction was estimated using the simplified surface energy balance (SSEB) approach. Based on the Simple Method, potential ET (PET) was estimated. Actual weekly wetland ET was computed as the (product of the PET and evaporative fraction). The ET product will be useful information for environmental restoration and wetland hydrology managers. The on-going restoration and monitoring work in the Everglades will benefit from this product and assist in evaluating progress and success in the restoration.

On the downscaling of actual evapotranspiration maps based on combination of MODIS and landsat-based actual evapotranspiration estimates

USGS Publications Warehouse

Singh, Ramesh K.; Senay, Gabriel B.; Velpuri, Naga Manohar; Bohms, Stefanie; Verdin, James P.

2014-01-01

 Downscaling is one of the important ways of utilizing the combined benefits of the high temporal resolution of Moderate Resolution Imaging Spectroradiometer (MODIS) images and fine spatial resolution of Landsat images. We have evaluated the output regression with intercept method and developed the Linear with Zero Intercept (LinZI) method for downscaling MODIS-based monthly actual evapotranspiration (AET) maps to the Landsat-scale monthly AET maps for the Colorado River Basin for 2010. We used the 8-day MODIS land surface temperature product (MOD11A2) and 328 cloud-free Landsat images for computing AET maps and downscaling. The regression with intercept method does have limitations in downscaling if the slope and intercept are computed over a large area. A good agreement was obtained between downscaled monthly AET using the LinZI method and the eddy covariance measurements from seven flux sites within the Colorado River Basin. The mean bias ranged from −16 mm (underestimation) to 22 mm (overestimation) per month, and the coefficient of determination varied from 0.52 to 0.88. Some discrepancies between measured and downscaled monthly AET at two flux sites were found to be due to the prevailing flux footprint. A reasonable comparison was also obtained between downscaled monthly AET using LinZI method and the gridded FLUXNET dataset. The downscaled monthly AET nicely captured the temporal variation in sampled land cover classes. The proposed LinZI method can be used at finer temporal resolution (such as 8 days) with further evaluation. The proposed downscaling method will be very useful in advancing the application of remotely sensed images in water resources planning and management.

Feasibility analysis of using inverse modeling for estimating field-scale evapotranspiration in maize and soybean fields from soil water content monitoring networks

NASA Astrophysics Data System (ADS)

Foolad, Foad; Franz, Trenton E.; Wang, Tiejun; Gibson, Justin; Kilic, Ayse; Allen, Richard G.; Suyker, Andrew

2017-03-01

In this study, the feasibility of using inverse vadose zone modeling for estimating field-scale actual evapotranspiration (ETa) was explored at a long-term agricultural monitoring site in eastern Nebraska. Data from both point-scale soil water content (SWC) sensors and the area-average technique of cosmic-ray neutron probes were evaluated against independent ETa estimates from a co-located eddy covariance tower. While this methodology has been successfully used for estimates of groundwater recharge, it was essential to assess the performance of other components of the water balance such as ETa. In light of recent evaluations of land surface models (LSMs), independent estimates of hydrologic state variables and fluxes are critically needed benchmarks. The results here indicate reasonable estimates of daily and annual ETa from the point sensors, but with highly varied soil hydraulic function parameterizations due to local soil texture variability. The results of multiple soil hydraulic parameterizations leading to equally good ETa estimates is consistent with the hydrological principle of equifinality. While this study focused on one particular site, the framework can be easily applied to other SWC monitoring networks across the globe. The value-added products of groundwater recharge and ETa flux from the SWC monitoring networks will provide additional and more robust benchmarks for the validation of LSM that continues to improve their forecast skill. In addition, the value-added products of groundwater recharge and ETa often have more direct impacts on societal decision-making than SWC alone. Water flux impacts human decision-making from policies on the long-term management of groundwater resources (recharge), to yield forecasts (ETa), and to optimal irrigation scheduling (ETa). Illustrating the societal benefits of SWC monitoring is critical to insure the continued operation and expansion of these public datasets.

Estimation of Regional-Scale Actual Evapotranspiration in Okayama prefecture in Japan using Complementary Relationship

NASA Astrophysics Data System (ADS)

Moroizumi, T.; Yamamoto, M.; Miura, T.

2008-12-01

It is important to estimate accurately a water balance in watershed for proposing a reuse of water resources and a proper settlement of water utilization. Evapotranspiration (ET) is an important factor of water balance. Therefore, it is needed to estimate accurately the actual ET. The objective of this study is to estimate accurately monthly actual ET in Yoshii, Asahi, and Takahashi River watersheds in Okayama prefecture from 1999 to 2000. The monthly actual ET was calculated by a Morton and a modified Brutsaert and Stricker (B&S) method, using Automated Meteorological Data Acquisition Systems (AMeDAS) in the basin. The actual ET was estimated using land covers which were classified in 11 categories. The land covers includes the effects of albedo. The actual ET was related to the elevation at each AMeDAS station. Using this relationship, the actual ET at the 1 or 5 km grid-interval mesh in the basin was calculated, and finally, the distribution of actual ET was mapped. The monthly ET estimated by the modified B&S method were smaller than that by Morton method which showed a same tendency as the Penman potential ET (PET). The annual values of Morton"fs ET, modified B&S"fs ET, and PET were estimated as 796, 645, and 800 mm, respectively. The ET by the modified B&S was larger in hilly and mountainous areas than in settlement or city. In general, it was a reasonable result because city or settlement areas were covered with concrete and asphalt and the ET was controlled.

Impacts of phenology on estimation of actual evapotranspiration with VegET model

NASA Astrophysics Data System (ADS)

Kovalskyy, V.; Henebry, G. M.

2009-12-01

The VegET model provides spatially explicit estimation of actual evapotranspiration (AET). Currently, it uses a climatology based on AVHRR NDVI image time series to modulate fluxes during growing seasons (Senay 2008). This step simplifies the model formulation, but it also introduces errors by ignoring the interannual variation in phenology. We report on a study to evaluate the effects of using an NDVI climatology in VegET rather than current season values. Using flux tower data from three sites across the US Corn Belt, we found that currently the model overestimates the duration of season. With the standard deviation of more than one week, the model results in an additional 50 to 70 mm of AET per season, which can account for about 10% of seasonal AET in drier western sites. The model showed only modest sensitivity to variation in growing season weather. This lack of sensitivity greatly decreased model accuracy during drought years: Pearson correlation coefficients between model estimates and observed values dropped from about 0.7 to 0.5, depending on vegetation type. We also evaluated an alternative approach to drive the canopy component of evapotranspiration, the Event Driven Phenology Model (EDPM). The parameterization of VegET with EDPM-simulated canopy dynamics improved the correlation by 0.1 or more and reduced the RMSE on daily AET estimates by 0.3 mm. By accounting for the progress of phenology during a particular growing season, the EDPM improves AET estimation over an NDVI climatology.

Modeling Actual Evapotranspiration From Forested Watersheds Across the Southeastern United States

Treesearch

Jianbiao Lu; Ge Sun; Steven G. McNulty; Devendra M. Amatya

2003-01-01

About 50 to 80 percent of precipitation in the southeastern United States returns to the atmosphere by evapotranspiration. As evapotranspiration is a major component in the forest water balances, accurately quantifying it is critical to predicting the effects of forest management and global change on water, sediment, and nutrient yield from forested watersheds. However...

Evaluation of Modeling Schemes to Estimate Evapotranspiration and Root Zone Soil Water Content over Vineyard using a Scintillometer and Remotely Sensed Surface Energy Balance

NASA Astrophysics Data System (ADS)

Geli, H. M. E.; Gonzalez-Piqueras, J.; Isidro, C., Sr.

2016-12-01

Actual crop evapotranspiration (ETa) and root zone soil water content (SMC) are key operational variable to monitor water consumption and water stress condition for improve vineyard grapes productivity and quality. This analysis, evaluates the estimation of ETa and SMC based on two modeling approaches. The first approach is a hybrid model that couples a thermal-based two source energy balance (TSEB) model (Norman et al. 1995) and water balance model to estimate the two variable (Geli 2012). The second approach is based on Large Aperture Scintillometer (LAS)-based estimates of sensible heat flux. The LAS-based estimates of sensible heat fluxes were used to calculate latent heat flux as the residual of surface energy balance equation on hourly basis which was converted to daily ETa. The calculated ETa from the scintillometer was then couple with the water balance approach to provide updated ETa_LAS and SMC_LAS. Both estimates of ETa and SMC based on LAS (i.e. ETa_LAS and SMC_LAS) and TSEB (ETa_TSEB and SMC_TSEB) were compared with ground-based observation from eddy covariance and soil water content measurements at multiple depths. The study site is an irrigated vineyard located in Central Spain Primary with heterogeneous surface conditions in term of irrigation practices and the ground based observation over the vineyard were collected during the summer of 2007. Preliminary results of the inter-comparison of the two approaches suggests relatively good between both modeling approaches and ground-based observations with RMSE lower than 1.2 mm/day for ETa and lower than 20% for SMC. References Norman, J. M., Kustas, W. P., & Humes, K. S. (1995). A two-source approach for estimating soil and vegetation energy fluxes in observations of directional radiometric surface temperature. Agricultural and Forest Meteorology, 77, 263293. Geli, Hatim M. E. (2012). Modeling spatial surface energy fluxes of agricultural and riparian vegetation using remote sensing, Ph. D. dissertation

Comparison of the effects of symmetric and asymmetric temperature elevation and CO2 enrichment on yield and evapotranspiration of winter wheat (Triticum aestivum L.).

PubMed

Qiao, Yunzhou; Liu, Huiling; Kellomäki, Seppo; Peltola, Heli; Liu, Yueyan; Dong, Baodi; Shi, Changhai; Zhang, Huizhen; Zhang, Chao; Gong, Jinnan; Si, Fuyan; Li, Dongxiao; Zheng, Xin; Liu, Mengyu

2014-05-01

Under the changing climate, asymmetric warming pattern would be more likely during day and night time, instead of symmetric one. Concurrently, the growth responses and water use of plants may be different compared with those estimated based on symmetric warming. In this work, it was compared with the effects of symmetric (ETs) and asymmetric (ETa) elevation of temperature alone, and in interaction with elevated carbon dioxide concentration (EC), on the grain yield (GY) and evapotranspiration in winter wheat (Triticum aestivum L.) based on pot experiment in the North China Plain (NCP). The experiment was carried out in six enclosed-top chambers with following climate treatments: (1) ambient temperature and ambient CO2 (CON), (2) ambient temperature and elevated CO2 (EC), (3) elevated temperature and ambient CO2 (ETs; ETa), and (4) elevated temperature and elevated CO2 (ECETs, ECETa). In symmetric warming, temperature was increased by 3°C and in asymmetric one by 3.5°C during night and 2.5°C during daytime, respectively. As a result, GY was in ETa and ETs 15.6 (P < 0.05) and 10.3% (P < 0.05) lower than that in CON. In ECETs and ECETa treatments, GY was 14.9 (P < 0.05) and 9.1% (P < 0.05) higher than that in CON. Opposite to GY, evapotranspiration was 7.8 (P < 0.05) and 17.9% (P < 0.05) higher in ETa and ETs treatments and 7.2 (P < 0.05) and 2.1% (P > 0.05) lower in ECETs and ECETa treatments compared with CON. Thus, GY of wheat could be expected to increase under the changing climate with concurrent elevation of CO2 and temperature as a result of increased WUE under the elevated CO2. However, the gain would be lower under ETa than that estimated based on ETs due to higher evapotranspiration.

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

USGS Publications Warehouse

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

2015-01-01

Satellite-derived evapotranspiration anomalies and normalized difference vegetation index (NDVI) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data are currently used for African agricultural drought monitoring and food security status assessment. In this study, a process to evaluate satellite-derived evapotranspiration (ETa) products with a geospatial statistical exploratory technique that uses NDVI, satellite-derived rainfall estimate (RFE), and crop yield data has been developed. The main goal of this study was to evaluate the ETa using the NDVI and RFE, and identify a relationship between the ETa and Ethiopia’s cereal crop (i.e., teff, sorghum, corn/maize, barley, and wheat) yields during the main rainy season. Since crop production is one of the main factors affecting food security, the evaluation of remote sensing-based seasonal ETa was done to identify the appropriateness of this tool as a proxy for monitoring vegetation condition in drought vulnerable and food insecure areas to support decision makers. The results of this study showed that the comparison between seasonal ETa and RFE produced strong correlation (R2 > 0.99) for all 41 crop growing zones in Ethiopia. The results of the spatial regression analyses of seasonal ETa and NDVI using Ordinary Least Squares and Geographically Weighted Regression showed relatively weak yearly spatial relationships (R2 < 0.7) for all cropping zones. However, for each individual crop zones, the correlation between NDVI and ETa ranged between 0.3 and 0.84 for about 44% of the cropping zones. Similarly, for each individual crop zones, the correlation (R2) between the seasonal ETa anomaly and de-trended cereal crop yield was between 0.4 and 0.82 for 76% (31 out of 41) of the crop growing zones. The preliminary results indicated that the ETa products have a good predictive potential for these 31 identified zones in Ethiopia. Decision makers may potentially use ETa products for monitoring cereal

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

NASA Astrophysics Data System (ADS)

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

2015-08-01

Satellite-derived evapotranspiration anomalies and normalized difference vegetation index (NDVI) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data are currently used for African agricultural drought monitoring and food security status assessment. In this study, a process to evaluate satellite-derived evapotranspiration (ETa) products with a geospatial statistical exploratory technique that uses NDVI, satellite-derived rainfall estimate (RFE), and crop yield data has been developed. The main goal of this study was to evaluate the ETa using the NDVI and RFE, and identify a relationship between the ETa and Ethiopia's cereal crop (i.e., teff, sorghum, corn/maize, barley, and wheat) yields during the main rainy season. Since crop production is one of the main factors affecting food security, the evaluation of remote sensing-based seasonal ETa was done to identify the appropriateness of this tool as a proxy for monitoring vegetation condition in drought vulnerable and food insecure areas to support decision makers. The results of this study showed that the comparison between seasonal ETa and RFE produced strong correlation (R2 > 0.99) for all 41 crop growing zones in Ethiopia. The results of the spatial regression analyses of seasonal ETa and NDVI using Ordinary Least Squares and Geographically Weighted Regression showed relatively weak yearly spatial relationships (R2 < 0.7) for all cropping zones. However, for each individual crop zones, the correlation between NDVI and ETa ranged between 0.3 and 0.84 for about 44% of the cropping zones. Similarly, for each individual crop zones, the correlation (R2) between the seasonal ETa anomaly and de-trended cereal crop yield was between 0.4 and 0.82 for 76% (31 out of 41) of the crop growing zones. The preliminary results indicated that the ETa products have a good predictive potential for these 31 identified zones in Ethiopia. Decision makers may potentially use ETa products for monitoring cereal crop

Evaluating the SSEBop approach for evapotranspiration mapping with landsat data using lysimetric observations in the semi-arid Texas High Plains

USGS Publications Warehouse

Senay, Gabriel; Gowda, Prasanna H.; Bohms, Stefanie; Howell, T.A.; Friedrichs, Mackenzie; Marek, T.H.; Verdin, James

2014-01-01

The operational Simplified Surface Energy Balance (SSEBop) approach was applied on 14 Landsat 5 thermal infrared images for mapping daily actual evapotranspiration (ETa) fluxes during the spring and summer seasons (March–October) in 2006 and 2007. Data from four large lysimeters, managed by the USDA-ARS Conservation and Production Research Laboratory were used for evaluating the SSEBop estimated ETa. Lysimeter fields are arranged in a 2 × 2 block pattern with two fields each managed under irrigated and dryland cropping systems. The modeled and observed daily ETa values were grouped as "irrigated" and "dryland" at four different aggregation periods (1-day, 2-day, 3 day and "seasonal") for evaluation. There was a strong linear relationship between observed and modeled ETa with R2 values ranging from 0.87 to 0.97. The root mean square error (RMSE), as percent of their respective mean values, were reduced progressively with 28, 24, 16 and 12% at 1-day, 2-day, 3-day, and seasonal aggregation periods, respectively. With a further correction of the underestimation bias (−11%), the seasonal RMSE reduced from 12 to 6%. The random error contribution to the total error was reduced from 86 to 20% while the bias' contribution increased from 14 to 80% when aggregated from daily to seasonal scale, respectively. This study shows the reliable performance of the SSEBop approach on the Landsat data stream with a transferable approach for use with the recently launched LDCM (Landsat Data Continuity Mission) Thermal InfraRed Sensor (TIRS) data. Thus, SSEBop can produce quick, reliable and useful ET estimations at various time scales with higher seasonal accuracy for use in regional water management decisions.

Comparison of the effects of symmetric and asymmetric temperature elevation and CO2 enrichment on yield and evapotranspiration of winter wheat (Triticum aestivum L.)

PubMed Central

Qiao, Yunzhou; Liu, Huiling; Kellomäki, Seppo; Peltola, Heli; Liu, Yueyan; Dong, Baodi; Shi, Changhai; Zhang, Huizhen; Zhang, Chao; Gong, Jinnan; Si, Fuyan; Li, Dongxiao; Zheng, Xin; Liu, Mengyu

2014-01-01

Under the changing climate, asymmetric warming pattern would be more likely during day and night time, instead of symmetric one. Concurrently, the growth responses and water use of plants may be different compared with those estimated based on symmetric warming. In this work, it was compared with the effects of symmetric (ETs) and asymmetric (ETa) elevation of temperature alone, and in interaction with elevated carbon dioxide concentration (EC), on the grain yield (GY) and evapotranspiration in winter wheat (Triticum aestivum L.) based on pot experiment in the North China Plain (NCP). The experiment was carried out in six enclosed-top chambers with following climate treatments: (1) ambient temperature and ambient CO2 (CON), (2) ambient temperature and elevated CO2 (EC), (3) elevated temperature and ambient CO2 (ETs; ETa), and (4) elevated temperature and elevated CO2 (ECETs, ECETa). In symmetric warming, temperature was increased by 3°C and in asymmetric one by 3.5°C during night and 2.5°C during daytime, respectively. As a result, GY was in ETa and ETs 15.6 (P < 0.05) and 10.3% (P < 0.05) lower than that in CON. In ECETs and ECETa treatments, GY was 14.9 (P < 0.05) and 9.1% (P < 0.05) higher than that in CON. Opposite to GY, evapotranspiration was 7.8 (P < 0.05) and 17.9% (P < 0.05) higher in ETa and ETs treatments and 7.2 (P < 0.05) and 2.1% (P > 0.05) lower in ECETs and ECETa treatments compared with CON. Thus, GY of wheat could be expected to increase under the changing climate with concurrent elevation of CO2 and temperature as a result of increased WUE under the elevated CO2. However, the gain would be lower under ETa than that estimated based on ETs due to higher evapotranspiration. PMID:24963392

Timescales of Land Surface Evapotranspiration Response

NASA Technical Reports Server (NTRS)

Scott, Russell; Entekhabi, Dara; Koster, Randal; Suarez, Max

1997-01-01

Soil and vegetation exert strong control over the evapotranspiration rate, which couples the land surface water and energy balances. A method is presented to quantify the timescale of this surface control using daily general circulation model (GCM) simulation values of evapotranspiration and precipitation. By equating the time history of evaporation efficiency (ratio of actual to potential evapotranspiration) to the convolution of precipitation and a unit kernel (temporal weighting function), response functions are generated that can be used to characterize the timescales of evapotranspiration response for the land surface model (LSM) component of GCMS. The technique is applied to the output of two multiyear simulations of a GCM, one using a Surface-Vegetation-Atmosphere-Transfer (SVAT) scheme and the other a Bucket LSM. The derived response functions show that the Bucket LSM's response is significantly slower than that of the SVAT across the globe. The analysis also shows how the timescales of interception reservoir evaporation, bare soil evaporation, and vegetation transpiration differ within the SVAT LSM.

The complementary relationship (CR) approach aids evapotranspiration estimation in the data scarce region of Tibetan Plateau: symmetric and asymmetric perspectives

NASA Astrophysics Data System (ADS)

Ma, N.; Zhang, Y.; Szilagyi, J.; Xu, C. Y.

2015-12-01

While the land surface latent and sensible heat release in the Tibetan Plateau (TP) could greatly influence the Asian monsoon circulation, the actual evapotranspiration (ETa) information in the TP has been largely hindered by its extremely sparse ground observation network. Thus the complementary relationship (CR) theory lends great potential in estimating the ETa since it relies on solely routine meteorological observations. With the in-situ energy/water flux observation over the highest semiarid alpine steppe in the TP, the modifications of specific components within the CR were first implemented. We found that the symmetry of the CR could be achieved for dry regions of TP when (i) the Priestley-Taylor coefficient, (ii) the slope of the saturation vapor pressure curve and (iii) the wind function were locally calibrated by using the ETa observations in wet days, an estimate of the wet surface temperature and the Monin-Obukhov Similarity (MOS) theory, respectively. In this way, the error of the simulated ETa by the symmetric AA model could be decreased to a large extent. Besides, the asymmetric CR was confirmed in TP when the D20 above-ground and/or E601B sunken pan evaporation (Epan) were used as a proxy of the ETp. Thus daily ETa could also be estimated by coupling D20 above-ground and/or E601B sunken pans through CR. Additionally, to overcome the modification of the specific components in the CR, we also evaluated the Nonlinear-CR model and the Morton's CRAE model. The former does not need the pre-determination of the asymmetry of CR, while the latter does not require the wind speed data as input. We found that both models are also able to simulate the daily ETa well provided their parameter values have been locally calibrated. The sensitivity analysis shows that, if the measured ETa data are absence to calibrate the models' parameter values, the Nonlinear-CR model may be a particularly good way for estimating ETabecause of its mild sensitivity to the parameter

Integrating satellite actual evapotranspiration patterns into distributed model parametrization and evaluation for a mesoscale catchment

NASA Astrophysics Data System (ADS)

Demirel, M. C.; Mai, J.; Stisen, S.; Mendiguren González, G.; Koch, J.; Samaniego, L. E.

2016-12-01

Distributed hydrologic models are traditionally calibrated and evaluated against observations of streamflow. Spatially distributed remote sensing observations offer a great opportunity to enhance spatial model calibration schemes. For that it is important to identify the model parameters that can change spatial patterns before the satellite based hydrologic model calibration. Our study is based on two main pillars: first we use spatial sensitivity analysis to identify the key parameters controlling the spatial distribution of actual evapotranspiration (AET). Second, we investigate the potential benefits of incorporating spatial patterns from MODIS data to calibrate the mesoscale Hydrologic Model (mHM). This distributed model is selected as it allows for a change in the spatial distribution of key soil parameters through the calibration of pedo-transfer function parameters and includes options for using fully distributed daily Leaf Area Index (LAI) directly as input. In addition the simulated AET can be estimated at the spatial resolution suitable for comparison to the spatial patterns observed using MODIS data. We introduce a new dynamic scaling function employing remotely sensed vegetation to downscale coarse reference evapotranspiration. In total, 17 parameters of 47 mHM parameters are identified using both sequential screening and Latin hypercube one-at-a-time sampling methods. The spatial patterns are found to be sensitive to the vegetation parameters whereas streamflow dynamics are sensitive to the PTF parameters. The results of multi-objective model calibration show that calibration of mHM against observed streamflow does not reduce the spatial errors in AET while they improve only the streamflow simulations. We will further examine the results of model calibration using only multi spatial objective functions measuring the association between observed AET and simulated AET maps and another case including spatial and streamflow metrics together.

Eta Carinae: Enigmatic Eta Carinae

NASA Astrophysics Data System (ADS)

Pittard, J. M.

2003-02-01

Eta Carinae is perhaps the most massive and luminous star in our galaxy, and is also one of the most enigmatic. Despite over a century and a half of study since an enormous eruption which expelled several solar masses of material into interstellar space, and which guaranteed its infamy, astronomers have struggled to understand its true nature. With a key event in the cycle of this star expected during the summer of 2003, an unprecedented programme of observations has been organized by astronomers around the world. Eta Carinae may at last be about to reveal some of its most fundamental secrets.

Actual evapotranspiration estimation in a Mediterranean mountain region by means of Landsat-5 TM and TERRA/AQUA MODIS imagery and Sap Flow measurements in Pinus sylvestris forest stands.

NASA Astrophysics Data System (ADS)

Cristóbal, J.; Poyatos, R.; Ninyerola, M.; Pons, X.; Llorens, P.

2009-04-01

Evapotranspiration monitoring has important implications on global and regional climate modelling, as well as in the knowledge of the hydrological cycle and in the assessment of environmental stress that affects forest and agricultural ecosystems. An increase of evapotranspiration while precipitation remains constant, or is reduced, could decrease water availability for natural and agricultural systems and human needs. Consequently, water balance methods, as the evapotranspiration modelling, have been widely used to estimate crop and forest water needs, as well as the global change effects. Nowadays, radiometric measurements provided by Remote Sensing and GIS analysis are the technologies used to compute evapotranspiration at regional scales in a feasible way. Currently, the 38% of Catalonia (NE of the Iberian Peninsula) is covered by forests, and one of the most important forest species is Scots Pine (Pinus sylvestris) which represents the 18.4% of the area occupied by forests. The aim of this work is to model actual evapotranspiration in Pinus sylvestris forest stands, in a Mediterranean mountain region, using remote sensing data, and compare it with stand-scale sap flow measurements measured in the Vallcebre research area (42° 12' N, 1° 49' E), in the Eastern Pyrenees. To perform this study a set of 30 cloud-free TERRA-MODIS images and 10 Landsat-5 TM images of path 198 and rows 31 and 32 from June 2003 to January 2005 have been selected to perform evapotranspiration modelling in Pinus sylvestris forest stands. TERRA/AQUA MODIS images have been downloaded by means of the EOS Gateway. We have selected two different types of products which contain the remote sensing data we have used to model daily evapotranspiration, daily LST product and daily calibrated reflectances product. Landsat-5 TM images have been corrected by means of conventional techniques based on first order polynomials taking into account the effect of land surface relief using a Digital

Interannual covariability between actual evapotranspiration and PAL and GIMMS NDVIs of northern Asia

USGS Publications Warehouse

Suzuki, Rikie; Masuda, Kooiti; Dye, Dennis G.

2007-01-01

This study examined the covariability between interannual changes in the normalized difference vegetation index (NDVI) and actual evapotranspiration (ET). To reduce possible uncertainty in the NDVI time series, two NDVI datasets derived from Pathfinder AVHRR Land (PAL) data and the Global Inventory Monitoring and Modeling Studies (GIMMS) group were used. Analyses were conducted using data over northern Asia from 1982 to 2000. Interannual changes over 19 years in the PAL-NDVI and GIMMS-NDVI were compared with interannual changes in ET estimated from model-assimilated atmospheric data and gridded precipitation data. For both NDVI datasets, the annual maximum correlation with ET occurred in June, which is the beginning of the vegetation growing season. The PAL and GIMMS datasets showed a significant, positive correlation between interannual changes in the NDVI and ET over most of the vegetated land area in June. These results suggest that interannual changes in vegetation activity predominantly control interannual changes in ET in June. Based on analyses of interannual changes in temperature, precipitation, and the NDVI in June, the study area can be roughly divided into two regions, the warmth-dominated northernmost region and the wetness-dominated southern region, indicating that interannual changes in vegetation and the resultant interannual changes in ET are controlled by warmth and wetness in these two regions, respectively.

Study of high momentum eta' production in B --> eta'Xs.

PubMed

Aubert, B; Barate, R; Boutigny, D; Couderc, F; Gaillard, J-M; Hicheur, A; Karyotakis, Y; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; LeClerc, C; Levi, M E; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Shelkov, V G; Telnov, A V; Wenzel, W A; Ford, K; Harrison, T J; Hawkes, C M; Morgan, S E; Watson, A T; Watson, N K; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schmuecker, H; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Mackay, C; Wilson, F F; Abe, K; Cuhadar-Donszelmann, T; Hearty, C; Mattison, T S; McKenna, J A; Thiessen, D; Kyberd, P; McKemey, A K; Teodorescu, L; Blinov, V E; Bukin, A D; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Gary, J W; Layter, J; Shen, B C; Wang, K; del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, Sh; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Beringer, J; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Walkowiak, W; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Erwin, R J; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Clark, P J; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Roy, J; Smith, J G; van Hoek, W C; Zhang, L; Harton, J L; Hu, T; Soffer, A; Toki, W H; Wilson, R J; Zhang, J; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Schubert, J; Schubert, K R; Schwierz, R; Spaan, B; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Khan, A; Lavin, D; Muheim, F; Playfer, S; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Taylor, G P; Grenier, G J; Lee, S-J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Brigljević, V; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Coleman, J P; Fry, J R; Gabathuler, E; Gamet, R; Kay, M; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Mohanty, G B; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; George, S; Green, M G; Kurup, A; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Cote-Ahern, D; Taras, P; Nicholson, H; Cartaro, C; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Wilden, L; Jessop, C P; LoSecco, J M; Gabriel, T A; Allmendinger, T; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; de la Vaissière, Ch; Del Buono, L; Hamon, O; John, M J J; Leruste, Ph; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Anulli, F; Biasini, M; Peruzzi, I M; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Del Gamba, V; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martinez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Varnes, E W; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Geddes, N I; Gopal, G P; Olaiya, E O; Xella, S M; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Hamel de Monchenault, G; Kozanecki, W; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yeche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Convery, M R; Cristinziani, M; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Elsen, E E; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wright, D H; Young, C C; Burchat, P R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R; Roney, J M; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Johnson, J R; Kutter, P E; Li, H; Liu, R; Di Lodovico, F; Mihalyi, A; Mohapatra, A K; Pan, Y; Prepost, R; Sekula, S J; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Neal, H

2004-08-06

We measure the branching fraction for the charmless semi-inclusive process B --> eta'Xs, where the eta' meson has a momentum in the range 2.0 to 2.7 GeV/c in the upsilon4S center-of-mass frame and Xs represents a system comprising a kaon and zero to four pions. We find B(B --> eta'Xs) = [3.9 +/- 0.8(stat) +/- 0.5(syst) +/- 0.8(model)] x 10(-4). We also obtain the Xs mass spectrum and find that it fits models predicting high masses.

Testing the Bouchet-Morton Complementary Hypothesis at Harvard Forest using Sap Flux Data

NASA Astrophysics Data System (ADS)

Pettijohn, J. C.; Salvucci, G. D.; Phillips, N. G.; Daley, M. J.

2005-12-01

The Bouchet-Morton Complementary Relationship (CR) states that at a given surface moisture availability (MA), changes in actual evapotranspiration (ETa) are reflected in changes in potential evapotranspiration (ETp) such that ETa + ETp = 2ET0, where ET0 is an assumed equilibrium evaporation condition at which ETa = ETp = ET0 at maximum MA. Whereas ETp conceptually includes a potential transpiration component, existing CR model estimates of ET_ {p are based upon the Penman combination equation for open water evaporation (ETp,Pen). Recent CR investigations for a temperate grassland at FIFE suggest, however, that the convergence between ETa and ETp,Pen will only occur if a maximum canopy conductance is included in the estimation of ETp. The purpose of this study was to conduct a field investigation at Harvard Forest to test the hypothesis that a CR-type relationship should occur between red maple ( Acer rubrum L.) actual transpiration and red maple potential transpiration, i.e., transpiration given unlimited root- zone MA via localized irrigation. Just as pan evaporation (ETp,Pen) is a physical gauge of ETp, we therefore question whether a well- irrigated maple is a potential transpirator. Daily averages of whole-tree transpiration for our co- occurring irrigated red maple network and reference network were calculated using high-frequency constant-heat sap flux sensor (i.e., Granier-type) measurements. Soil moisture, temperature and matric potential parameters were measured using Campbell Scientific sensors. Preliminary results suggest that the relationship between potential and actual transpiration differs significantly from ETa and ETp,Pen in the context of CR, adding useful insight into both ETp estimation and the understanding of physiological response to MA variability.

Temporal downscaling of crop coefficients for winter wheat in the North China Plain: A case study at the Gucheng ecological-meteorological experimental station

USDA-ARS?s Scientific Manuscript database

The crop coefficient (Kc) method is widely used for operational estimation of actual evapotranspiration (ETa) and crop water requirements. The standard method for obtaining Kc is via a lookup table from FAO-56 (Food and Agriculture Organization of the United Nations Irrigation and Drainage Paper No....

Eta Squared, Partial Eta Squared, and Misreporting of Effect Size in Communication Research.

ERIC Educational Resources Information Center

Levine, Timothy R.; Hullett, Craig R.

2002-01-01

Alerts communication researchers to potential errors stemming from the use of SPSS (Statistical Package for the Social Sciences) to obtain estimates of eta squared in analysis of variance (ANOVA). Strives to clarify issues concerning the development and appropriate use of eta squared and partial eta squared in ANOVA. Discusses the reporting of…

Actual evapotranspiration for a reference crop within measured and future changing climate periods in the Mediterranean region

NASA Astrophysics Data System (ADS)

Katerji, Nader; Rana, Gianfranco; Ferrara, Rossana Monica

2017-08-01

The study compares two formulas for calculating the daily evapotranspiration ET0 for a reference crop. The first formula was proposed by Allen et al. (AL), while the second one was proposed by Katerji and Perrier with the addition of the carbon dioxide (CO2) effect on evapotranspiration (KP). The study analyses the impact of the calculation by the two formulas on the irrigation requirement (IR). Both formulas are based on the Penman-Monteith equation but adopt different approaches for parameterising the canopy resistance r c . In the AL formula, r c is assumed constant and not sensitive to climate change, whereas in the KP formula, r c is first parameterised as a function of climatic variables, then ET0 is corrected for the air CO2 concentration. The two formulas were compared in two periods. The first period involves data from two sites in the Mediterranean region within a measured climate change period (1981-2006) when all the input climatic variables were measured. The second period (2070-2100) involves data from a future climate change period at one site when the input climatic variables were forecasted for two future climate scenarios (A2 and B2). The annual cumulated values of ET0 calculated by the AL formula are systematically lower than those determined by the KP formula. The differences between the ET0 estimation with the AL and KP formulas have a strong impact on the determination of the IR for the reference crop. In fact, for the two periods, the annual values of IR when ET0 is calculated by the AL formula are systematically lower than those calculated by the KP formula. For the actual measured climate change period, this reduction varied from 26 to 28 %, while for the future climate change period, it varied based on the scenario from 16 % (A2) to 20 % (B2).

Measurement of the eta-meson mass using psi(2S) --> etaJ/psi.

PubMed

Miller, D H; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Ge, J Y; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Ernst, J; Ecklund, K M; Severini, H; Love, W; Savinov, V; Lopez, A; Mehrabyan, S; Mendez, H; Ramirez, J

2007-09-21

We measure the mass of the eta meson using psi(2S) --> etaJ/psi events acquired with the CLEO-c detector operating at the CESR e(+)e(-) collider. Using the four decay modes eta --> gamma gamma, 3pi(0), pi(+)pi(-)pi(0), and pi(+)pi(-)gamma, we find M(eta) = 547.785 +/- 0.017 +/- 0.057 MeV, in which the first uncertainty is statistical and the second systematic. This result has an uncertainty comparable to the two most precise previous measurements and is consistent with that of NA48, but is inconsistent at the level of 6.5 sigma with the much smaller mass obtained by GEM.

Spatial assessment of water use in an environmentally sensitive wetland.

PubMed

Khan, Shahbaz; Hafeez, Mohsin; Abbas, Akhtar; Ahmad, Aftab

2009-05-01

Wetlands are among the most valuable ecosystems in the world and are crucial in supporting biodiversity. They also provide space for storing surface waters, where intense biological processing occurs that helps improve water quality. Human activities, particularly irrigated agriculture and urban developments instigating water diversions from rivers, have altered the hydrology of most wetlands. The Lower Murrumbidgee wetland, located in the Murrumbidgee River Catchment, is an example and is one of the significant wetlands across the Murray Darling Basin of Australia. Historic estimates show the volumes of water ranged from none in dry years to about 300 to 400 GL (1 GL = 10(9) L) in an average and wet year, respectively. The flows reaching the Lower Murrumbidgee wetland have been drastically reduced by at least 60% because of the upstream diversions introduced during the last century. These reductions have adversely affected the health of natural vegetation and agricultural crops in the Lower Murrumbidgee floodplain. This article presents the results of the quantification of total water consumption of various land uses in the Lower Murrumbidgee floodplain using the remote sensing-based Surface Energy Balance Algorithm for Land (SEBAL) modeling approach. The spatial analysis of actual evapotranspiration (ETa) shows that ETa rates are the highest (13-26%) for the red gum (Eucalyptus camaldulensis) forests both in summer and winter days. However, in terms of total ETa volume, lignum (Muehlenbeckia florulenta) constitutes the most significant part, which is around 14-30% of the total ETa volume for the area. Actual evapotranspiration from winter cereal cropping areas following the summer ponding is the third highest consumer of water after the river red gum and lignum. Actual evapotranspiration from the fallow land is also significant, representing 5-28% of total ETa from the region. In view of the extent of the unaccounted flows in the overall water balance of the

Operational Retrievals of Evapotranspiration: Are we there yet?

NASA Astrophysics Data System (ADS)

Neale, C. M. U.; Anderson, M. C.; Hain, C.; Schull, M.; Isidro, C., Sr.; Goncalves, I. Z.

2017-12-01

Remote sensing based retrievals of evapotranspiration (ET) have progressed significantly over the last two decades with the improvement of methods and algorithms and the availability of multiple satellite sensors with shortwave and thermal infrared bands on polar orbiting platforms. The modeling approaches include simpler vegetation index (VI) based methods such as the reflectance-based crop coefficient approach coupled with surface reference evapotranspiration estimates to derive actual evapotranspiration of crops or, direct inputs to the Penman-Monteith equation through VI relationships with certain input variables. Methods that are more complex include one-layer or two-layer energy balance approaches that make use of both shortwave and longwave spectral band information to estimate different inputs to the energy balance equation. These models mostly differ in the estimation of sensible heat fluxes. For continental and global scale applications, other satellite-based products such as solar radiation, vegetation leaf area and cover are used as inputs, along with gridded re-analysis weather information. This presentation will review the state-of-the-art in satellite-based evapotranspiration estimation, giving examples of existing efforts to obtain operational ET retrievals over continental and global scales and discussing difficulties and challenges.

A comparison of six potential evapotranspiration methods for regional use in the Southeastern United States

Treesearch

Jianbiao Lu; Ge Sun; Steven G. McNulty; Devendra Amatya

2005-01-01

Potential evapotranspiration (PET) is an important index of hydrologic budgets at different spatial scales and is a critical variable for understanding regional biological processes. It is often an important variable in estimating actual evapotranspiration (AET) in rainfall-runoff and ecosystem modeling. However, PET is defined in different ways in the literature and...

Observation of D+ --> etae + nue.

PubMed

Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Smith, A; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Ernst, J; Ecklund, K M; Severini, H; Love, W; Savinov, V; Aquines, O; Lopez, A; Mehrabyan, S; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Butt, J; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Potlia, V; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Selen, M; White, E J; Wiss, J

2009-02-27

Using a 281 pb-1 data sample collected at the psi(3770) resonance with the CLEO-c detector at the Cornell Electron Storage Ring, we report the first observation of D+ --> etae + nue. We also set upper limits for D+ --> eta'e + nue and D + --> varphie + nue that are about 2 orders of magnitude more restrictive than those obtained by previous experiments.

Theoretical characterization of stable eta1-N2O-, eta2-N2O-, eta1-N2-, and eta2-N2-bound species: intermediates in the addition reactions of nitrogen hydrides with the pentacyanonitrosylferrate(II) ion.

PubMed

Olabe, José A; Estiú, Guillermina L

2003-08-11

The addition of nitrogen hydrides (hydrazine, hydroxylamine, ammonia, azide) to the pentacyanonitrosylferrate(II) ion has been analyzed by means of density functional calculations, focusing on the identification of stable intermediates along the reaction paths. Initial reversible adduct formation and further decomposition lead to the eta(1)- and eta(2)-linkage isomers of N(2)O and N(2), depending on the nucleophile. The intermediates (adducts and gas-releasing precursors) have been characterized at the B3LYP/6-31G level of theory through the calculation of their structural and spectroscopic properties, modeling the solvent by means of a continuous approach. The eta(2)-N(2)O isomer is formed at an initial stage of adduct decompositions with the hydrazine and azide adducts. Further conversion to the eta(1)-N(2)O isomer is followed by Fe-N(2)O dissociation. Only the eta(1)-N(2)O isomer is predicted for the reaction with hydroxylamine, revealing a kinetically controlled N(2)O formation. eta(1)-N(2) and eta(2)-N(2) isomers are also predicted as stable species.

Using remote sensing to characterize and compare evapotranspiration from different irrigation regimes in the Smith River Watershed of central Montana

USGS Publications Warehouse

Sando, Thomas R.; Caldwell, Rodney R.; Blasch, Kyle W.

2017-01-01

According to the 2005 U.S. Geological Survey national water use compilation, irrigation is the second largest use of fresh water in the United States, accounting for 37%, or 484.48 million cubic meters per day, of total freshwater withdrawal. Accurately estimating the amount of water withdrawals and actual consumptive water use (the difference between water withdrawals and return flow) for irrigation at a regional scale is difficult. Remote sensing methods make it possible to compare actual ET (ETa) rates which can serve as a proxy for consumptive water use from different irrigation regimes at a regional scale in a systematic manner. This study investigates crucial components of water use from irrigation such as the difference of ETa rates from flood- and sprinkler-irrigated fields, spatial variability of ETa within a watershed, and the effect of sprinkler irrigation on the water budget of the study area. The mean accumulated ETa depth for the 1,051 square kilometer study area within the upper Smith River watershed was about 467 mm 30-meter per pixel for the 2007 growing season (April through mid-October). The total accumulated volume of ETa for the study area was about 474.705 million cubic meters. The mean accumulated ETa depth from sprinkler-irrigated land was about 687 mm and from flood-irrigated land was about 621 mm from flood-irrigated land. On average, the ETa rate from sprinkler-irrigated fields was 0.25 mm per day higher than flood-irrigated fields over the growing season. Spatial analysis showed that ETa rates within individual fields of a single crop type that are irrigated with a single method (sprinkler or flood) can vary up to about 8 mm per day. It was estimated that the amount of sprinkler irrigation in 2007 accounted for approximately 3% of the total volume of ETa in the study area. When compared to non-irrigated dryland, sprinkler irrigation increases ETa by about 59 to 82% per unit area.

Some Comments on the Decays of eta (550)

DOE R&D Accomplishments Database

Veltman, M.; Yellin, J.

1966-07-01

Various decay modes of the {eta}(500) are discussed. The relations, through SU{sub 3} and the Gell-Mann, Sharp, Wagner model, between the {eta}-decay modes and the modes {eta} {yields} {pi}{pi}{gamma), {pi}{sup 0} {yields} {gamma}{gamma} are investigated taking into account {eta}-{eta}{sup *} mixing. The present experimental values for the neutral branching ratios plus the shape of the {eta} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} Dalitz plot are shown to require a 25% {vert_bar}{Delta}{rvec I}{vert_bar} = 3 contribution to the {eta} {yields} 3{pi} amplitude. The connection between a possible charge asymmetry in {eta} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} and the branching ratio {Gamma}{sub {eta} {yields} {pi}{sup 0}e{sup +}e{sup {minus}}}/{Gamma}{sub {eta}}{sup all} is investigated in the framework of a model proposed earlier by several authors. It is shown that there is no conflict between the existing data and this model. The Dalitz plot distribution of {eta} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} is discussed under various assumptions about the properties of the interaction responsible for the decay. (auth)

Evaluation of remotely sensed actual evapotranspiration data for modeling small scale irrigation in Ethiopia.

NASA Astrophysics Data System (ADS)

Taddele, Y. D.; Ayana, E.; Worqlul, A. W.; Srinivasan, R.; Gerik, T.; Clarke, N.

2017-12-01

The research presented in this paper is conducted in Ethiopia, which is located in the horn of Africa. Ethiopian economy largely depends on rainfed agriculture, which employs 80% of the labor force. The rainfed agriculture is frequently affected by droughts and dry spells. Small scale irrigation is considered as the lifeline for the livelihoods of smallholder farmers in Ethiopia. Biophysical models are highly used to determine the agricultural production, environmental sustainability, and socio-economic outcomes of small scale irrigation in Ethiopia. However, detailed spatially explicit data is not adequately available to calibrate and validate simulations from biophysical models. The Soil and Water Assessment Tool (SWAT) model was setup using finer resolution spatial and temporal data. The actual evapotranspiration (AET) estimation from the SWAT model was compared with two remotely sensed data, namely the Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectrometer (MODIS). The performance of the monthly satellite data was evaluated with correlation coefficient (R2) over the different land use groups. The result indicated that over the long term and monthly the AVHRR AET captures the pattern of SWAT simulated AET reasonably well, especially on agricultural dominated landscapes. A comparison between SWAT simulated AET and AVHRR AET provided mixed results on grassland dominated landscapes and poor agreement on forest dominated landscapes. Results showed that the AVHRR AET products showed superior agreement with the SWAT simulated AET than MODIS AET. This suggests that remotely sensed products can be used as valuable tool in properly modeling small scale irrigation.

Divergence of actual and reference evapotranspiration observations for irrigated sugarcane with windy tropical conditions

NASA Astrophysics Data System (ADS)

Anderson, R. G.; Wang, D.; Tirado-Corbalá, R.; Zhang, H.; Ayars, J. E.

2015-01-01

Standardized reference evapotranspiration (ET) and ecosystem-specific vegetation coefficients are frequently used to estimate actual ET. However, equations for calculating reference ET have not been well validated in tropical environments. We measured ET (ETEC) using eddy covariance (EC) towers at two irrigated sugarcane fields on the leeward (dry) side of Maui, Hawaii, USA in contrasting climates. We calculated reference ET at the fields using the short (ET0) and tall (ETr) vegetation versions of the American Society for Civil Engineers (ASCE) equation. The ASCE equations were compared to the Priestley-Taylor ET (ETPT) and ETEC. Reference ET from the ASCE approaches exceeded ETEC during the mid-period (when vegetation coefficients suggest ETEC should exceed reference ET). At the windier tower site, cumulative ETr exceeded ETEC by 854 mm over the course of the mid-period (267 days). At the less windy site, mid-period ETr still exceeded ETEC, but the difference was smaller (443 mm). At both sites, ETPT approximated mid-period ETEC more closely than the ASCE equations ((ETPT-ETEC) < 170 mm). Analysis of applied water and precipitation, soil moisture, leaf stomatal resistance, and canopy cover suggest that the lower observed ETEC was not the result of water stress or reduced vegetation cover. Use of a custom-calibrated bulk canopy resistance improved the reference ET estimate and reduced seasonal ET discrepancy relative to ETPT and ETEC in the less windy field and had mixed performance in the windier field. These divergences suggest that modifications to reference ET equations may be warranted in some tropical regions.

ETA: Helping to Improve American Worklife.

ERIC Educational Resources Information Center

Employment and Training Administration (DOL), Washington, DC.

This booklet serves as an introduction to the Employment and Training Administration (ETA) and describes the ETA's development and the services it provides to employers and jobseekers. It details programs, field services, history, prime objectives, and the 1978 legislation concerning ETA and CETA. Special areas discussed in detail are the…

Comment on 'Shang S. 2012. Calculating actual crop evapotranspiration under soil water stress conditions with appropriate numerical methods and time step. Hydrological Processes 26: 3338-3343. DOI: 10.1002/hyp.8405'

NASA Technical Reports Server (NTRS)

Yatheendradas, Soni; Narapusetty, Balachandrudu; Peters-Lidard, Christa; Funk, Christopher; Verdin, James

2014-01-01

A previous study analyzed errors in the numerical calculation of actual crop evapotranspiration (ET(sub a)) under soil water stress. Assuming no irrigation or precipitation, it constructed equations for ET(sub a) over limited soil-water ranges in a root zone drying out due to evapotranspiration. It then used a single crop-soil composite to provide recommendations about the appropriate usage of numerical methods under different values of the time step and the maximum crop evapotranspiration (ET(sub c)). This comment reformulates those ET(sub a) equations for applicability over the full range of soil water values, revealing a dependence of the relative error in numerical ET(sub a) on the initial soil water that was not seen in the previous study. It is shown that the recommendations based on a single crop-soil composite can be invalid for other crop-soil composites. Finally, a consideration of the numerical error in the time-cumulative value of ET(sub a) is discussed besides the existing consideration of that error over individual time steps as done in the previous study. This cumulative ET(sub a) is more relevant to the final crop yield.

Measurements of the mass and width of the eta(c) meson and of an eta(c)(2S) candidate.

PubMed

Aubert, B; Barate, R; Boutigny, D; Gaillard, J-M; Hicheur, A; Karyotakis, Y; Lees, J P; Robbe, P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kral, J F; Kukartsev, G; LeClerc, C; Levi, M E; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Romosan, A; Ronan, M T; Shelkov, V G; Telnov, A V; Wenzel, W A; Ford, K; Harrison, T J; Hawkes, C M; Knowles, D J; Morgan, S E; Penny, R C; Watson, A T; Watson, N K; Deppermann, T; Goetzen, K; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schmuecker, H; Steinke, M; Barlow, N R; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Mackay, C; Wilson, F F; Abe, K; Cuhadar-Donszelmann, T; Hearty, C; Mattison, T S; McKenna, J A; Thiessen, D; Kyberd, P; McKemey, A K; Blinov, V E; Bukin, A D; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Shen, B C; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, Sh; Schwanke, U; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Kuznetsova, N; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Beringer, J; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Turri, M; Walkowiak, W; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Clark, P J; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Roy, J; Smith, J G; Van Hoek, W C; Zhang, L; Harton, J L; Hu, T; Soffer, A; Toki, W H; Wilson, R J; Zhang, J; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Dubitzky, R S; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Schubert, J; Schubert, K R; Schwierz, R; Spaan, B; Wilden, L; Bernard, D; Bonneaud, G R; Brochard, F; Cohen-Tanugi, J; Grenier, P; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Khan, A; Lavin, D; Muheim, F; Playfer, S; Swain, J E; Tinslay, J; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Anulli, F; Baldini-Ferroli, R; Biasini, M; Calcaterra, A; De Sangro, R; Falciai, D; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Pioppi, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Morii, M; Won, E; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Eschrich, I; Gaillard, J R; Morton, G W; Nash, J A; Sanders, P; Taylor, G P; Grenier, G J; Lee, S-J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Brigljević, V; Cheng, C H; Lange, D J; Wright, D M; Bevan, A J; Coleman, J P; Fry, J R; Gabathuler, E; Gamet, R; Kay, M; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Shorthouse, H W; Strother, P; Vidal, P B; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; George, S; Green, M G; Kurup, A; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, R J; Forti, A C; Hart, P A; Jackson, F; Lafferty, G D; Lyon, A J; Weatherall, J H; Williams, J C; Farbin, A; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Milek, M; Patel, P M; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Cote-Ahern, D; Hast, C; Taras, P; Nicholson, H; Cartaro, C; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; LoSecco, J M; Gabriel, T A; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Wong, Q K; Brau, J; Frey, R; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; de la Vaissière, Ch; Del Buono, L; Hamon, O; John, M J J; Leruste, Ph; Ocariz, J; Pivk, M; Roos, L; Stark, J; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martinez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Tanaka, H A; Varnes, E W; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Geddes, N I; Gopal, G P; Olaiya, E O; Xella, S M; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Hamel de Monchenault, G; Kozanecki, W; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yeche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Convery, M R; Coupal, D P; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Grauges-Pous, E; Hadig, T; Halyo, V; Hryn'ova, T; Innes, W R; Jessop, C P; Kelsey, M H; Kim, P; Kocian, M L; Langenegger, U; Leith, D W G S; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Robertson, S H; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wright, D H; Young, C C; Burchat, P R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R; Roney, J M; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Johnson, J R; Kutter, P E; Li, H; Liu, R; Di Lodovico, F; Mihalyi, A; Mohapatra, A K; Pan, Y; Prepost, R; Sekula, S J; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Neal, H

2004-04-09

The mass m(eta(c)) and total width Gamma(eta(c))(tot) of the eta(c) meson have been measured in two-photon interactions at the SLAC e(+)e(-) asymmetric B Factory with the BABAR detector. With a sample of approximately 2500 reconstructed eta(c)-->K(0)(S)K+/-pi(-/+) decays in 88 fb(-1) of data, the results are m(eta(c))=2982.5+/-1.1(stat)+/-0.9(syst) MeV/c(2) and Gamma(eta(c))(tot)=34.3+/-2.3(stat)+/-0.9(syst) MeV/c(2). Using the same decay mode, a second resonance with 112+/-24 events is observed with a mass of 3630.8+/-3.4(stat)+/-1.0(syst) MeV/c(2) and width of 17.0+/-8.3(stat)+/-2.5(syst) MeV/c(2). This observation is consistent with expectations for the eta(c)(2S) state.

Understanding the relationship between actual and potential evapotranspirations from long- term water balance analysis and flux observation

NASA Astrophysics Data System (ADS)

Yang, D.; Yang, H.; Sun, F.

2007-12-01

potential evaporations are plotted against the time (year) during the same period. This means that complementary idea cannot provide universally correct predictions on the trend of actual evaporation only from the potential one. In this research, we examine the coupled water-energy balance based on Budyko hypothesis and proposed a conceptual model for predicting the inter-annual variability of annual water balance, and the change trends of water balances due to climate changes. The wet environment evaporation was defined as the boundary condition in the Bouchet hypothesis and introduced into complementary relationship (CR), which combined the actual evaporation with potential evaporation in an equation. However, the CR was derived in a closed system where no horizontal energy advection existed. The effect of the horizontal advection on the CR in a real open system was also analyzed in this study. Using the long-term water balance analysis in the 108 study catchments and flux observation at 7 sites in Asia monsoon region, the regional and seasonal variability of the complementary relationship was examined. Key Words: climate change, evapotranspiration, water balance, flux observation, Budyko hypothesis, Bouchet hypothesis

A coupled remote sensing and the Surface Energy Balance based algorithms to estimate actual evapotranspiration over the western and southern regions of Saudi Arabia

NASA Astrophysics Data System (ADS)

Mahmoud, Shereif H.; Alazba, A. A.

2016-07-01

In countries with absolute water scarcity such as the Kingdom of Saudi Arabia (KSA), large-scale actual evapotranspiration estimation is of great concern in water use practices. Herein, spatial and temporal distribution of actual evapotranspiration (AET) in the western and southern regions of KSA during 1992-2014 was estimated using the SEBAL model with field observations. Zonal statistics for each land use-cover type were also identified, in order to understand their effects on water consumption. In addition, daily and seasonal water consumption for major crops was computed. Results revealed a gradual increase in monthly AET values from January to April and subsequent decline from May to December. The maximum monthly AET values were observed for irrigated cropland in southwestern, central, and southeastern regions of Asir Province, central and southwestern regions of Al-Baha Province, central and the plains region of Jazan Province, southern portion of Makkah Province, and limited areas in the northern regions of Madinah Province. The annual AET ranged from 418.8 to 3442.3 mm yr-1. The normal distribution of mean annual AET values ranged from 717 to 1020 mm yr-1. Forty-two percent of the study area had an annual AET that ranged from 717 to 1020 mm yr-1. The second highest range of frequencies was concentrated around 1020-1322 mm yr-1, representing the majority of agricultural land. The consumptive water use of the different land cover types in study area indicated that irrigated cropland which occupied 14.6% of the study area had AET rates much higher than other land uses. Water bodies are the next highest, with forest and shrubland and sparse vegetation slightly lower, and very low AET rates from bare soil. Daily and seasonal water consumption of major cropping systems varied spatially depending on cropping practices and climatic conditions.

Actual evapotranspiration and deficit: Biologically meaningful correlates of vegetation distribution across spatial scales

USGS Publications Warehouse

Stephenson, N.L.

1998-01-01

Correlative approaches to understanding the climatic controls of vegetation distribution have exhibited at least two important weaknesses: they have been conceptually divorced across spatial scales, and their climatic parameters have not necessarily represented aspects of climate of broad physiological importance to plants. Using examples from the literature and from the Sierra Nevada of California, I argue that two water balance parameters-actual evapotranspiration (AET) and deficit (D)-are biologically meaningful, are well correlated with the distribution of vegetation types, and exhibit these qualities over several orders of magnitude of spatial scale (continental to local). I reach four additional conclusions. (1) Some pairs of climatic parameters presently in use are functionally similar to AET and D; however, AET and D may be easier to interpret biologically. (2) Several well-known climatic parameters are biologically less meaningful or less important than AET and D, and consequently are poorer correlates of the distribution of vegetation types. Of particular interest, AET is a much better correlate of the distributions of coniferous and deciduous forests than minimum temperature. (3) The effects of evaporative demand and water availability on a site's water balance are intrinsically different. For example, the 'dry' experienced by plants on sunward slopes (high evaporative demand) is not comparable to the 'dry' experienced by plants on soils with low water-holding capacities (low water availability), and these differences are reflected in vegetation patterns. (4) Many traditional topographic moisture scalars-those that additively combine measures related to evaporative demand and water availability are not necessarily meaningful for describing site conditions as sensed by plants; the same holds for measured soil moisture. However, using AET and D in place of moisture scalars and measured soil moisture can solve these problems.

Does dinitrogen hydrogenation follow different mechanisms for [(eta5-C5Me4H)2Zr]2(mu2,eta2,eta2-N2) and {[PhP(CH2SiMe2NSiMe2CH2)PPh]Zr}2(mu2,eta2,eta2-N2) complexes? A computational study.

PubMed

Bobadova-Parvanova, Petia; Wang, Qingfang; Quinonero-Santiago, David; Morokuma, Keiji; Musaev, Djamaladdin G

2006-09-06

The mechanisms of dinitrogen hydrogenation by two different complexes--[(eta(5)-C(5)Me(4)H)(2)Zr](2)(mu(2),eta(2),eta(2)-N(2)), synthesized by Chirik and co-workers [Nature 2004, 427, 527], and {[P(2)N(2)]Zr}(2)(mu(2),eta(2),eta(2)-N(2)), where P(2)N(2) = PhP(CH(2)SiMe(2)NSiMe(2)CH(2))(2)PPh, synthesized by Fryzuk and co-workers [Science 1997, 275, 1445]--are compared with density functional theory calculations. The former complex is experimentally known to be capable of adding more than one H(2) molecule to the side-on coordinated N(2) molecule, while the latter does not add more than one H(2). We have shown that the observed difference in the reactivity of these dizirconium complexes is caused by the fact that the former ligand environment is more rigid than the latter. As a result, the addition of the first H(2) molecule leads to two different products: a non-H-bridged intermediate for the Chirik-type complex and a H-bridged intermediate for the Fryzuk-type complex. The non-H-bridged intermediate requires a smaller energy barrier for the second H(2) addition than the H-bridged intermediate. We have also examined the effect of different numbers of methyl substituents in [(eta(5)-C(5)Me(n)H(5)(-)(n))(2)Zr](2)(mu(2),eta(2),eta(2)-N(2)) for n = 0, 4, and 5 (n = 5 is hypothetical) and [(eta(5)-C(5)H(2)-1,2,4-Me(3))(eta(5)-C(5)Me(5))(2)Zr](2)(mu(2),eta(2),eta(2)-N(2)) and have shown that all complexes of this type would follow a similar H(2) addition mechanism. We have also performed an extensive analysis on the factors (side-on coordination of N(2) to two Zr centers, availability of the frontier orbitals with appropriate symmetry, and inflexibility of the catalyst ligand environment) that are required for successful hydrogenation of the coordinated dinitrogen.

The seismology of eta Bootes

NASA Technical Reports Server (NTRS)

Demarque, Pierre; Guenther, D. B.

1995-01-01

Some p-mode frequencies and other observations were used to determine the mass, the age and the helium abundance of eta Bootes. It is shown how, by direct application, the p-mode frequencies and stellar seismological tools help in constraining the physical parameters of eta Boo. The existence of mode bumping is confirmed and it is discussed how it may be used to refine the estimate of the eta Boo's age. The effect of the OPAL equation of state on the p-mode frequencies is described.

Role of the N*(1535) in {eta}{sup '} production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao Xu; Graduate School, Chinese Academy of Sciences, Beijing 100049; Lee Xiguo

2008-09-15

We study the near-threshold {eta}{sup '} production mechanism in nucleon-nucleon and {pi}N collisions under the assumption that subthreshold resonance N*(1535) is predominant. In an effective Lagrangian approach that gives a reasonable description to the pN{yields}pN{eta} and {pi}{sup -}p{yields}n{eta} reactions, we find that the excitation of N*(1535) resonance from the t-channel {pi} exchange makes the dominate contribution to the pN{yields}pN{eta}{sup '} process, and a value of 6.5 for the ratio of {sigma}(pn{yields}pn{eta}{sup '}) to {sigma}(pp{yields}pp{eta}{sup '}) is predicted. A strongcoupling strength of N*(1535) to {eta}{sup '}N (g{sub {eta}{sup '}}{sub NN*}{sup 2}/4{pi}=1.1) is extracted from a combined analysis to pp{yields}pp{eta}{sup '} andmore » {pi}N{yields}N{eta}{sup '}, and the possible implication to the intrinsic component of N*(1535) is explored.« less

Measurement of the eta'-meson mass using J/psi-->gammaeta'.

PubMed

Libby, J; Martin, L; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; Mendez, H; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Reed, J; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hunt, J M; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Ledoux, J; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A

2008-10-31

We measure the mass of the eta;{'} meson using psi(2S)-->pi;{+}pi;{-}J/psi, J/psi-->gammaeta;{'} events acquired with the CLEO-c detector operating at the CESR e;{+}e;{-} collider. Using three decay modes, eta;{'}-->rho;{0}gamma, eta;{'}-->pi;{+}pi;{-}eta with eta-->gammagamma, and eta;{'}-->pi;{+}pi;{-}eta with eta-->pi;{+}pi;{-}pi;{0}, we find M_{eta;{'}}=957.793+/-0.054+/-0.036 MeV, in which the uncertainties are statistical and systematic, respectively. This result is consistent with but substantially more precise than the current world average.

Annual variability of water productivity components in the watershed of Cabeceira Comprida stream, Santa Fé do Sul, Brazil

NASA Astrophysics Data System (ADS)

Coaguila, Daniel N.; Hernandez, Fernando B. T.; de C. Teixeira, Antônio H.; Neale, Christopher M.; Franco, Renato A. M.; Leivas, Janice F.

2016-10-01

The Cabeceira Comprida stream's watershed, located in Santa Fé do Sul, Brazil, is an agroecosystem with great demand of water for the population and agriculture. During the dry season the water demand exceeds the amount generated by the watershed. It is important to know the dynamics of the water above the ground to improve the water resources management. Ten Landsat 8 images were used combined with Northwestern São Paulo State Weather Network data under different thermohydrological conditions of the year 2014 to quantify actual evapotranspiration (ETa), biomass production (BIO) and water productivity (WP) based on ETa. Using the Simple Algorithm for Retrieving evapotranspiration (SAFER) for calculating ETa, the Monteith's radiation model was applied for estimating the BIO and for calculation of WP the ratio of BIO and ETa. The average pixels for ETa, BIO and WP ranged respectively from 0.38 +/- 0.35 to 2.05 +/- 0.76 mm day-1; 10.15 +/- 12.19 to 71.61 +/- 35.54 kg ha-1 day-1; 1.89 +/- 0.76 to 3.88 +/- 0.86 kg m-3. The lower values of ETa (0.38 mm day-1; DOY 220), BIO (10.15 kg ha-1 day-1; DOY 220) and WP (1.89 kg m-3; DOY 204) were obtained in winter, and highest values of ETa (2.05 mm day-1; DOY 364) and BIO (71.64 kg ha-1 day-1; DOY 364) in the summer and WP (3.88 kg m-3; DOY 92) in the autumn. The water productivity components can subsidize the monitoring of the agro-ecosystems, being a useful tool to quantify the annual variability of ETa and BIO.

Spatial modelling of evapotranspiration in the Luquillo experimental forest of Puerto Rico using remotely-sensed data.

Treesearch

Wei Wu; Charles A.S. Hall; Frederick N. Scatena; Lindi J. Quackenbush

2006-01-01

Summary Actual evapotranspiration (aET) and related processes in tropical forests can explain 70% of the lateral global energy transport through latent heat, and therefore are very important in the redistribution of water on the Earth’s surface [Mauser, M., Scha¨dlich, S., 1998. Modelling the spatial distribution of evapotranspiration on different scales using remote...

Long-term potential and actual evapotranspiration of two different forests on the Atlantic Coastal Plain

Treesearch

Devendra Amatya; S. Tian; Z. Dai; Ge Sun

2016-01-01

A reliable estimate of potential evapotranspiration (PET) for a forest ecosystem is critical in ecohydrologic modeling related with water supply, vegetation dynamics, and climate change and yet is a challenging task due to its complexity. Based on long-term on-site measured hydro-climatic data and predictions from earlier validated hydrologic modeling studies...

ETA-MACRO: A user's guide

NASA Astrophysics Data System (ADS)

Manne, A. S.

1981-02-01

The ETA-MACRO model is designed to estimate the extent of two way linkage between the energy sector and the balance of the economy. It represents a merger between ETA (a process analysis for energy technology assessment) together with a macroeconomic growth model providing for substitution between capital, labor, and energy inputs. The ETA-MACRO allows explicitly for: (1) energy economy interactions; (2) cost effective conservation; (3) interfuel substitution, and (4) new supply technologies, each with its own difficulties and uncertainties on dates and rates of introduction. This user's guide includes an overview of the model, an illustrative application to long term US energy projections, and technical descriptions of the macro and ETA submodels. It also includes an analysis of how market penetration rates may be related to the profitability of new technologies. Finally, the appendices provide a detailed guide to the computer implementation.

Investigation of near-threshold eta-meson production in the reaction {pi}{sup -}p{yields} {eta}n

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bayadilov, D. E.; Beloglazov, Yu. A.; Gridnev, A. B.

2012-08-15

Differential and total cross sections for eta-meson production in the reaction {pi}{sup -}p {yields} {eta}n were measured within the experimental program eta-meson physics implemented in the pion channel of the synchrocyclotron of the Petersburg Nuclear Physics Institute (PNPI, Gatchina). These measurements were performed at incident-pion momenta (700, 710, 720, and 730 MeV/c) in the vicinity of the threshold for the process under study by using the neutral-meson spectrometer designed and created at the Meson Physics Laboratory of PNPI. It is shown that, in the immediate vicinity of the threshold (685 MeV/c), the process of eta-meson production proceeds predominantly via S{submore » 11}(1535)-resonance formation followed by the decay S{sub 11}(1535) {yields} {eta}n (the respective branching fraction is Br Almost-Equal-To 60%), but that, as the momentum of incident pions increases, the role of the D wave becomes ever more important. A detailed analysis of this effect indicates that it is due to the increasing contribution of the D{sub 13}(1520) resonance. Although the branching fraction of the decay of this resonance through the {eta}n channel is assumed to be very small (BR Almost-Equal-To 0.24%), the effect is enhanced owing to the interference between the D wave and the dominant resonance S{sub 11}(1535).« less

Measurement of the Color-Suppressed B0->D(*)0 pi0 /omega/eta/eta Prime Branching Fractions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prudent, X

2008-11-05

The authors report results on the branching fraction (BF) measurement of the color-suppressed decays {bar B}{sup 0} {yields} D{sup 0}{pi}{sup 0}, D*{sup 0}{pi}{sup 0}, D{sup 0}{eta}, D*{sup 0}{eta}, D{sup 0}{omega}, D*{sup 0}{omega}, D{sup 0}{eta}{prime}, and D*{sup 0}{eta}{prime}. They measure the branching fractions BF(D{sup 0}{pi}{sup 0}) = (2.78 {+-} 0.08 {+-} 0.20) x 10{sup -4}, BF(D*{sup 0}{pi}{sup 0}) = (1.78 {+-} 0.13 {+-} 0.23) x 10{sup -4}, BF(D{sup 0}{eta}) = (2.41 {+-} 0.09 {+-} 0.17) x 10{sup -4}, BF(D*{sup 0}{eta}) = (2.32 {+-} 0.13 {+-} 0.22) x 10{sup -4}, BF(D{sup 0}{omega}) = (2.77 {+-} 0.13 {+-} 0.22) x 10{sup -4}, BF(D*{supmore » 0}{omega}) = (4.44 {+-} 0.23 {+-} 0.61) x 10{sup -4}, BF(D{sup 0}{eta}{prime}) = (1.38 {+-} 0.12 {+-} 0.22) x 10{sup -4} and BF(D*{sup 0}{eta}{prime}) = (1.29 {+-} 0.23 {+-} 0.23) x 10{sup -4}, where the first uncertainty is statistical and the second is systematic. The result is based on a sample of (454 {+-} 5) x 10{sup 6} B{bar B} pairs collected at the {Upsilon}(4S) resonance from 1999 to 2007, with the BABAR detector at the PEP-II storage rings at the Stanford Linear Accelerator Center. The measurements are compared to theoretical predictions by factorization, SCET and pQCD. The presence of final state interactions predictions by factorization, SCET and pQCD. The presence of final state interactions is confirmed and the measurements seem to be more in favor of SCET compared to pQCD.« less

Eta Squared and Partial Eta Squared as Measures of Effect Size in Educational Research

ERIC Educational Resources Information Center

Richardson, John T. E.

2011-01-01

Eta squared measures the proportion of the total variance in a dependent variable that is associated with the membership of different groups defined by an independent variable. Partial eta squared is a similar measure in which the effects of other independent variables and interactions are partialled out. The development of these measures is…

A comparison of operational remote sensing-based models for estimating crop evapotranspiration

USDA-ARS?s Scientific Manuscript database

The integration of remotely sensed data into models of actual evapotranspiration has allowed for the estimation of water consumption across agricultural regions. Two modeling approaches have been successfully applied. The first approach computes a surface energy balance using the radiometric surface...

Structure and mechanism of human DNA polymerase [eta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biertümpfel, Christian; Zhao, Ye; Kondo, Yuji

2010-11-03

The variant form of the human syndrome xeroderma pigmentosum (XPV) is caused by a deficiency in DNA polymerase {eta} (Pol{eta}), a DNA polymerase that enables replication through ultraviolet-induced pyrimidine dimers. Here we report high-resolution crystal structures of human Pol{eta} at four consecutive steps during DNA synthesis through cis-syn cyclobutane thymine dimers. Pol{eta} acts like a 'molecular splint' to stabilize damaged DNA in a normal B-form conformation. An enlarged active site accommodates the thymine dimer with excellent stereochemistry for two-metal ion catalysis. Two residues conserved among Pol{eta} orthologues form specific hydrogen bonds with the lesion and the incoming nucleotide to assistmore » translesion synthesis. On the basis of the structures, eight Pol{eta} missense mutations causing XPV can be rationalized as undermining the molecular splint or perturbing the active-site alignment. The structures also provide an insight into the role of Pol{eta} in replicating through D loop and DNA fragile sites.« less

Greenup and evapotranspiration following the Minute 319 pulse flow to Mexico: An analysis using Landsat 8 Normalized Difference Vegetation Index (NDVI) data

USGS Publications Warehouse

Jarchow, Christopher J.; Nagler, Pamela L.; Glenn, Edward P.

2017-01-01

In the southwestern U.S., many riparian ecosystems have been altered by dams, water diversions, and other anthropogenic activities. This is particularly true of the Colorado River, where numerous dams and agricultural diversions have affected this water course, especially south of the U.S.–Mexico border. In the spring of 2014, 130 million cubic meters of water was released to the lower Colorado River Delta in Mexico. To understand the impact of this pulse flow release on vegetation in the delta’s riparian corridor, we analyzed a modified form of Landsat 8 Operational Land Imager (OLI) Normalized Difference Vegetation Index (NDVI*) data. We assessed greenup during the growing period and estimated actual evapotranspiration (ETa) for the period prior to (yr. 2013) and following (i.e., yr. 2014 and 2015) the pulse flow. We found a significant increase in NDVI* from 2013 to 2014 (P < 0.05) and a decrease from 2014 to 2015; however, 2015 levels were still significantly higher than in 2013. ETa was also higher in 2014 vs. 2013, with an estimated 74.5 million cubic meters in 2013 and 88.9 in 2014. The most intense greening occurred in the zone of inundation but also extended into the non-flooded part of the riparian zone, indicating replenishment of groundwater. These findings suggest the peak response by vegetation to the flow lasted about one year, followed by a decrease in NDVI*. As a long term solution to the declining condition of vegetation, additional pulse releases are likely needed for restoration and survival of riparian plant communities in the Colorado River Delta.

Measurement of prominent eta-decay branching fractions.

PubMed

Lopez, A; Mehrabyan, S; Mendez, H; Ramirez, J; Ge, J Y; Miller, D H; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Ernst, J; Ecklund, K M; Severini, H; Love, W; Savinov, V

2007-09-21

The decay psi(2S) --> etaJ/psi is used to measure, for the first time, all prominent eta-meson branching fractions with the same experiment in the same dataset, thereby providing a consistent treatment of systematics across branching fractions. We present results for eta decays to gamma gamma, pi(+)pi(-)pi(0), 3pi(0), pi(+)pi(-)gamma and e(+)e(-)gamma, accounting for 99.9% of all eta decays. The precision of several of the branching fractions and their ratios is improved. Two channels, pi(+)pi(-)gamma and e(+)e(-)gamma, show results that differ at the level of three standard deviations from those previously determined.

Comparison of prognostic and diagnostic approached to modeling evapotranspiration in the Nile river basin

USDA-ARS?s Scientific Manuscript database

Actual evapotranspiration (ET) can be estimated using both prognostic and diagnostic modeling approaches, providing independent yet complementary information for hydrologic applications. Both approaches have advantages and disadvantages. When provided with temporally continuous atmospheric forcing d...

Determination of actual crop evapotranspiration (ETc) and dual crop coefficients (Kc) for cotton, wheat and maize in Fergana Valley: integration of the FAO-56 approach and BUDGET

NASA Astrophysics Data System (ADS)

Kenjabaev, Shavkat; Dernedde, Yvonne; Frede, Hans-Georg; Stulina, Galina

2014-05-01

Determination of the actual crop evapotranspiration (ETc) during the growing period is important for accurate irrigation scheduling in arid and semi-arid regions. Development of a crop coefficient (Kc) can enhance ETc estimations in relation to specific crop phenological development. This research was conducted to determine daily and growth-stage-specific Kc and ETc values for cotton (Gossypium hirsutum L.), winter wheat (Triticum aestivum L.) and maize (Zea mays L.) for silage at fields in Fergana Valley (Uzbekistan). The soil water balance model - Budget with integration of the dual crop procedure of the FAO-56 was used to estimate the ETc and separate it into evaporation (Ec) and transpiration (Tc) components. An empirical equation was developed to determine the daily Kc values based on the estimated Ec and Tc. The ETc, Kc determination and comparison to existing FAO Kc values were performed based on 10, 5 and 6 study cases for cotton, wheat and maize, respectively. Mean seasonal amounts of crop water consumption in terms of ETc were 560±50, 509±27 and 243±39 mm for cotton, wheat and maize, respectively. The growth-stage-specific Kc for cotton, wheat and maize was 0.15, 0.27 and 0.11 at initial; 1.15, 1.03 and 0.56 at mid; and 0.45, 0.89 and 0.53 at late season stages. These values correspond to those reported by the FAO-56. Development of site specific Kc helps tremendously in irrigation management and furthermore provides precise water applications in the region. The developed simple approach to estimate daily Kc for the three main crops grown in the Fergana region was a first attempt to meet this issue. Keywords: Actual crop evapotranspiration, evaporation and transpiration, crop coefficient, model BUDGET, Fergana Valley.

20 CFR 655.1292 - Authority of ETA-OFLC.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Authority of ETA-OFLC. 655.1292 Section 655... Employment in the United States (H-2A Workers) § 655.1292 Authority of ETA-OFLC. Temporary agricultural labor... Department of Labor's (the Department or DOL) Employment & Training Administration (ETA), who, in turn, may...

Eta Carina: What was the Great Eruption in the 19th Century?

NASA Astrophysics Data System (ADS)

Gull, Theodore; Eta Carina Bunch

2018-01-01

In the 1840’s, Eta Carina brightened to rival Sirius in apparent magnitude only to fade to naked-eye visibility for 5 decades, brightened somewhat in the 1890s and faded again until the 1940’s when it began a progressive brightening that continues. Today Eta Carina is a massive binary (100 Mo and 30 Mo) with a 5.54-year period, immersed in a massive (>40Mo) dusty, bipolar nebula. The radiation and kinetic energy of the 1840s event rivals that of a supernova, but the binary survived. While Eta Carina is suggested to be a supernova imposter, most imposters, seen in nearby galaxies, lead to actual supernova events months to years afterwards, yet the binary, Eta Carina, is still with us 170 years after the outburst.With modern observatories we are gaining much insight on the massive binary--followed by many ground-based telescopes, the fossil wind structures--mapped with HST/STIS, the Little Homunculus--discovered with HST/STIS and Homunculus--now being studied with ALMA. 3D models are able to explain much of the structures, but potentially much material remains hidden in the form of molecules on the far side of the Homunculus in the equatorial skirt region, where Herschel observations indicate the bulk of dust-emitting continuum resides.Was there a third star that became a supernova? Did one of the two stars go through a near supernova experience?This poster will summarize observations and modeling of the current system in hopes that theorists will become interested in providing scenarios and models that led to the ejecta and binary we observe today.

Observation of eta'c production in gammagamma fusion at CLEO.

PubMed

Asner, D M; Dytman, S A; Mehrabyan, S; Mueller, J A; Nam, S; Savinov, V; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shibata, E I; Shipsey, I P J; Adams, G S; Chasse, M; Cummings, J P; Danko, I; Napolitano, J; Cronin-Hennessy, D; Park, C S; Park, W; Thayer, J B; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Stroynowski, R; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Haynes, J; Menaa, N; Mountain, R; Muramatsu, H; Nandakumar, R; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, Kevin; Mahmood, A H; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Bornheim, A; Lipeles, E; Pappas, S P; Shapiro, A; Weinstein, A J; Mahapatra, R; Nelson, H N; Briere, R A; Chen, G P; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Adam, N E; Alexander, J P; Berkelman, K; Boisvert, V; Cassel, D G; Duboscq, J E; Ecklund, K M; Ehrlich, R; Galik, R S; Gibbons, L; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Magerkurth, A; Mahlke-Krüger, H; Meyer, T O; Patterson, J R; Pedlar, T K; Peterson, D; Pivarski, J; Riley, D; Sadoff, A J; Schwarthoff, H; Shepherd, M R; Sun, W M; Thayer, J G; Urner, D; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Potlia, V; Stoeck, H; Yelton, J; Eisenstein, B I; Gollin, G D; Karliner, I; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Thaler, J J; Williams, J; Edwards, K W; Besson, D; Gao, K Y; Gong, D T; Kubota, Y; Li, S Z; Poling, R; Scott, A W; Smith, A; Stepaniak, C J; Urheim, J; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Arms, K; Eckhart, E; Gan, K K; Gwon, C; Severini, H; Skubic, P

2004-04-09

We report on the observation of the eta(')(c)(2(1)S0), the radial excitation of the eta(c)(1(1)S0) ground state of charmonium, in the two-photon fusion reaction gammagamma-->eta(')(c)-->K(0)(S)K+/-pi(-/+) in 13.6 fb(-1) of CLEO II/II.V data and 13.1 fb(-1) of CLEO III data. We obtain M(eta(')(c))=3642.9+/-3.1(stat)+/-1.5(syst) MeV and M(eta(c))=2981.8+/-1.3(stat)+/-1.5(syst) MeV. The corresponding values of hyperfine splittings between 1S0 and 3S1 states are DeltaM(hf)(1S)=115.1+/-2.0 MeV and DeltaM(hf)(2S)=43.1+/-3.4 MeV. Assuming that the eta(c) and eta(')(c) have equal branching fractions to K(S)Kpi, we obtain Gamma(gammagamma)(eta(')(c))=1.3+/-0.6 keV.

Influence of potential evapotranspiration on the water balance of sugarcane fields in Maui, Hawaii

USDA-ARS?s Scientific Manuscript database

The year-long warm temperatures and other climatic characteristics of the Pacific Ocean Islands have made Hawaii an optimum place for growing sugarcane; however, irrigation is essential to satisfy the large water demand of sugarcane. Under the Hawaiian tropical weather, actual evapotranspiration (A...

Software Users Manual (SUM): Extended Testability Analysis (ETA) Tool

NASA Technical Reports Server (NTRS)

Maul, William A.; Fulton, Christopher E.

2011-01-01

This software user manual describes the implementation and use the Extended Testability Analysis (ETA) Tool. The ETA Tool is a software program that augments the analysis and reporting capabilities of a commercial-off-the-shelf (COTS) testability analysis software package called the Testability Engineering And Maintenance System (TEAMS) Designer. An initial diagnostic assessment is performed by the TEAMS Designer software using a qualitative, directed-graph model of the system being analyzed. The ETA Tool utilizes system design information captured within the diagnostic model and testability analysis output from the TEAMS Designer software to create a series of six reports for various system engineering needs. The ETA Tool allows the user to perform additional studies on the testability analysis results by determining the detection sensitivity to the loss of certain sensors or tests. The ETA Tool was developed to support design and development of the NASA Ares I Crew Launch Vehicle. The diagnostic analysis provided by the ETA Tool was proven to be valuable system engineering output that provided consistency in the verification of system engineering requirements. This software user manual provides a description of each output report generated by the ETA Tool. The manual also describes the example diagnostic model and supporting documentation - also provided with the ETA Tool software release package - that were used to generate the reports presented in the manual

Measuring Evapotranspiration in Urban Irrigated Lawns in Two Kansas Cities

NASA Astrophysics Data System (ADS)

Shonkwiler, K. B.; Bremer, D.; Ham, J. M.

2011-12-01

Conservation of water is becoming increasingly critical in many metropolitan areas. The use of automated irrigation systems for the maintenance of lawns and landscapes is rising and these systems are typically maladjusted to apply more water than necessary, resulting in water wastage. Provision of accurate estimates of actual lawn water use may assist urbanites in conserving water through better adjustment of automatic irrigation systems. Micrometeorological methods may help determine actual lawn water use by measuring evapotranspiration (ET) from urban lawns. From April - August of 2011, four small tripod-mounted weather stations (tripods, five total) were deployed in twelve residential landscapes in the Kansas cities of Manhattan (MHK) and Wichita (ICT) in the USA (six properties in each city). Each tripod was instrumented to estimate reference crop evapotranspiration (ETo) via the FAO-56 method. During tripod deployment in residential lawns, actual evapotranspiration (ETactual) was measured nearby using a stationary, trailer-mounted eddy covariance (EC) station. The EC station sampled well-watered turf at the K-State Rocky Ford Turfgrass Center within 5 km of the study properties in MHK, and was also deployed at a commercial sod farm 15 - 40 km from the study residences in the greater ICT metro area. The fifth tripod was deployed in the source area of the EC station to estimate ETo in conjunction with tripods in the lawns (i.e., to serve as a reference). Data from EC allowed for computation of a so-called lawn coefficient (Kc) by determining the ratio of ETo from the tripods in residential lawns to ETo from the EC station (ETo,EC); hence, Kc = ETo,tripod / ETo,EC. Using this method, ETactual can be estimated for individual tripods within a lawn. Data suggests that it may be more accurate to quantify ET within individual lawns by microclimate (i.e., determine coefficients for "shaded" and "open/unshaded" portions of a lawn). By finding microclimate coefficients

Detection of a Hot Binary Companion of eta Carinae

NASA Technical Reports Server (NTRS)

Sonnebom, G.; Iping, R. C.; Gull, T. R.; Massa, D. L.; Hillier, D. J.

2006-01-01

A hot companion of eta Carinae has been detected using high resolution spectra (905 - 1180 A) obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. Observations were obtained at two epochs of the 2024-day orbit: 2003 June during ingress to the 2003.5 X-ray eclipse and 2004 April several months after egress. These data show that essentially all the far-UV flux from eta Car shortward of Lyman alpha disappeared at least two days before the start of the X-ray eclipse (2003 June 29), implying that the hot companion, eta Car B, was also eclipsed by the dense wind or extended atmosphere of eta Car A. Analysis of the far-UV spectrum shows that eta Car B is a luminous hot star. N II 1084-1086 emission disappears at the same time as the far-UV continuum, indicating that this feature originates from eta Car B itself or in close proximity to it. The strong N II emission also raises the possibility that the companion star is nitrogen rich. The observed FUV flux levels and spectral features, combined with the timing of their disappearance, is consistent with eta Carinae being a massive binary system

Detection of a Hot Binary Companion of eta Carinae

NASA Technical Reports Server (NTRS)

Sonneborn, G.; Iping, R. C.; Gull, T. R.; Massa, D.; Hillier, D. J.

2006-01-01

A hot companion of eta Carinae has been detected using high resolution spectra (905 - 1 180 Angsroms) obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. Observations were obtained at two epochs of the 2024-day orbit: 2003 June during ingress to the 2003.5 X-ray eclipse and 2004 April several months after egress. These data show that essentially all the far-UV flux from eta Car shortward of Lyman alpha disappeared at least two days before the start of the X-ray eclipse (2003 June 29), implying that the hot companion, eta Car By was also eclipsed by the dense wind or extended atmosphere of eta Car A. Analysis of the far-UV spectrum shows that eta Car B is a luminous hot star. N II 1084-1086 emission disappears at the same time as the far-UV continuum, indicating that this feature originates from eta Car B itself or in close proximity to it. The strong N II emission also raises the possibility that the companion star is nitrogen rich. The observed FUV flux levels and spectral features, combined with the timing of their disappearance, are consistent with eta Carinae being a massive binary system.

Eta Carinae: Orientation of The Orbital Plane

NASA Technical Reports Server (NTRS)

Gull, T. R.; Nielsen, K. E.; Ivarsson, S.; Corcoran, M. F.; Verner, E.; Hillier, J. D.

2006-01-01

Evidence continues to build that Eta Carinae is a massive binary system with a hidden hot companion in a highly elliptical orbit. We present imaging and spectroscopic evidence that provide clues to the orientation of the orbital plane. The circumstellar ejecta, known as the Homunculus and Little Homunculus, are hourglass-shaped structures, one encapsulated within the other, tilted at about 45 degrees from the sky plane. A disk region lies between the bipolar lobes. Based upon their velocities and proper motions, Weigelt blobs B, C and D, very bright emission clumps 0.1 to 0.3" Northwest from Eta Carinae, lie in the disk. UV flux from the hot companion, Eta Car B, photoexcites the Weigelt blobs. Other clumps form a complete chain around the star, but are not significantly photoexcited. The strontium filament, a 'neutral' emission structure, lies in the same general direction as the Weigelt blobs and exhibits peculiar properties indicative that much mid-UV, but no hydrogen-ionizing radiation impinges on this structure. It is shielded by singly-ionized iron. P Cygni absorptions in Fe I I lines, seen directly in line of sight from Eta Carinae, are absent in the stellar light scattered by the Weigelt blobs. Rather than a strong absorption extending to -600 km/s, a low velocity absorption feature extends from -40 to -150 km/s. No absorbing Fe II exists between Eta Carinae and Weigelt D, but the outer reaches of the wind are intercepted in line of sight from Weigelt D to the observer. This indicates that the UV radiation is constrained by the dominating wind of Eta Car A to a small cavity carved out by the weaker wind of Eta Car B. Since the high excitation nebular lines are seen in the Weigelt blobs at most phases, the cavity, and hence the major axis of the highly elliptical orbit, must lie in the general direction of the Weigelt blobs. The evidence is compelling that the orbital major axis of Eta Carinae is projected at -45 degrees position angle on the sky. Moreover

All Pillars Point to Eta

NASA Technical Reports Server (NTRS)

2005-01-01

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Eta Carinae Starforming RegionSimulated Infrared View of Comet Tempel 1 (artist's concept)

These false-color image taken by NASA's Spitzer Space Telescope shows the 'South Pillar' region of the star-forming region called the Carina Nebula. Like cracking open a watermelon and finding its seeds, the infrared telescope 'busted open' this murky cloud to reveal star embryos (yellow or white) tucked inside finger-like pillars of thick dust (pink). Hot gases are green and foreground stars are blue. Not all of the newfound star embryos can be easily spotted.

Though the nebula's most famous and massive star, Eta Carinae, is too bright to be observed by infrared telescopes, the downward-streaming rays hint at its presence above the picture frame. Ultraviolet radiation and stellar winds from Eta Carinae and its siblings have shredded the cloud to pieces, leaving a mess of tendrils and pillars. This shredding process triggered the birth of the new stars uncovered by Spitzer.

The inset visible-light picture (figure 2) of the Carina Nebula shows quite a different view. Dust pillars are fewer and appear dark because the dust is soaking up visible light. Spitzer's infrared detectors cut through this dust, allowing it to see the heat from warm, embedded star embryos, as well as deeper, more buried pillars. The visible-light picture is from the National Optical Astronomy Observatory.

Eta Carina is a behemoth of a star, with more than 100 times the mass of our Sun. It is so massive that it can barely hold itself together. Over the years, it has brightened and faded as material has shot away from its surface. Some astronomers think Eta Carinae might die in a supernova blast within our lifetime.

Eta Carina's home, the Carina Nebula, is located in the southern portion of our Milky Way galaxy, 10,000 light-years from Earth. This colossal cloud of gas and dust

Branching fraction measurements of {chi}{sub c0} and {chi}{sub c2} to {pi}{sup 0{pi}0} and {eta}{eta}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ablikim, M.; An, Z. H.; Bai, J. Z.

2010-03-01

Using a sample of 1.06x10{sup 8} {psi}{sup '} decays collected by the BESIII detector, {chi}{sub c0} and {chi}{sub c2} decays into {pi}{sup 0{pi}0} and {eta}{eta} are studied. The branching fraction results are Br({chi}{sub c0{yields}{pi}}{sup 0{pi}0})=(3.23{+-}0.03{+-}0.23{+-}0.14)x10{sup -3}, Br({chi}{sub c2{yields}{pi}}{sup 0{pi}0})=(8.8{+-}0.2{+-}0.6{+-}0.4)x10{sup -4}, Br({chi}{sub c0{yields}{eta}{eta}})=(3.44{+-}0.10{+-}0.24{+-}0.2)x10{sup -3}, and Br({chi}{sub c2{yields}{eta}{eta}})=(6.5{+-}0.4{+-}0.5{+-}0.3)x10{sup -4}, where the uncertainties are statistical, systematic due to this measurement, and systematic due to the branching fractions of {psi}{sup '{yields}{gamma}{chi}}{sub cJ}. The results provide information on the decay mechanism of {chi}{sub c} states into pseudoscalars.

Blaney-Morin-Nigeria evapotranspiration model

NASA Astrophysics Data System (ADS)

Duru, J. Obiukwu

1984-02-01

An evapotranspiration model which parallels that proposed earlier by Blaney and Morin has been developed for application in Nigeria. The model, designated as the Blaney-Morin-Nigeria evapotranspiration model, predicts potential evapotranspiration with accuracy and consistency that are better than the Penman model, under Nigerian conditions. It is suggested that the Blaney-Morin evapotranspiration concept may have similar potential elsewhere when given specific form with appropriate constants derived to reflect climatic peculiarities.

Ground Observation of Asteroids at Mission ETA

NASA Astrophysics Data System (ADS)

Paganelli, F.; Conrad, A.

2018-04-01

We focused on Lucy's targeted asteroids to derive information for best ground-based observation at mission ETA. We used a workflow for data extraction through JPL Horizons considering the LBT-MODS 1. Results outline opportunities suitable during close approach of Lucy ETA.

NAM - Eta to NMM conversion 20060613

Science.gov Websites

North American Mesoscale (NAM) time slot. Currently the the Eta forecast model is used for the NAM, but Eta and its output will be available at the same time. There will be some minor addition of products MB per file (time step). - The following fields will be added: - omega @ 10, 20, & 30 mb - height

Evapotranspiration Calculator Desktop Tool

EPA Pesticide Factsheets

The Evapotranspiration Calculator estimates evapotranspiration time series data for hydrological and water quality models for the Hydrologic Simulation Program - Fortran (HSPF) and the Stormwater Management Model (SWMM).

Experimental study of pp{eta} dynamics with WASA-at-COSY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, Neha

2011-10-24

To investigate the interaction of {eta}-meson with the nucleons, its production, near the kinematical threshold, in proton-proton collisions has been studied with the WASA detector at COSY storage ring in Juelich, Germany. The data has been taken at beam energy 1400 MeV (corresponding to excess energy (Q = 57 MeV). The {eta}-meson was detected via its 3{pi}{sup 0} decay in nearly 4{pi} detector and two protons were measured in forward direction. The determination of four vectors of both protons and the {eta}-meson in the final state allowed to derive complete kinematical information of the pp{eta}-system. The analysis resulted in 9x10{supmore » 6} events of {eta}{yields}3{pi}{sup 0} giving total production cross-section (8.87{+-}0.03{sub stat}{+-}2.57{sub sys}){mu}b. The angular distribution of {eta}-meson in the center of mass frame is anisotropic and squared invariant mass distributions for proton-proton and proton-{eta} shows deviation from pure phase space.« less

Eta- and Partial Eta-Squared in L2 Research: A Cautionary Review and Guide to More Appropriate Usage

ERIC Educational Resources Information Center

Norouzian, Reza; Plonsky, Luke

2018-01-01

Eta-squared (?[superscript 2]) and partial eta-squared (?[subscript p][superscript 2]) are effect sizes that express the amount of variance accounted for by one or more independent variables. These indices are generally used in conjunction with ANOVA, the most commonly used statistical test in second language (L2) research (Plonsky, 2013).…

Searching for Radial Velocity Variations in eta Carinae

NASA Technical Reports Server (NTRS)

Iping, R. C.; Sonneborn, G.; Gull, T. R.; Ivarsson, S.; Nielsen, K.

2006-01-01

A hot companion of eta Carinae has been detected using high resolution spectra (905 - 1180 A) obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite (see poster by Sonneborn et al.). Analysis of the far-UV spectrum shows that eta Car B is a luminous hot star. The N II 1084-86 emission feature indicates that the star may be nitrogen rich. The FUV continuum and the S IV 1073 P-Cygni wind line suggest that the effective temperature of eta Car B is at least 25,000 K. FUV spectra of eta Carinae were obtained with the FUSE satellite at 9 epochs between 2000 February and 2005 July. The data consists of 12 observations taken with the LWRS aperture (30x30 arcsec), three with the HIRS aperture (1.25x20 arcsec), and one MRDS aperture (4x20 arcsec). In this paper we discuss the analysis of these spectra to search for radial velocity variations associated with the 5.54-year binary orbit of Eta Car AB.

Assessment of actual transpiration rate in olive tree field combining sap-flow, leaf area index and scintillometer measurements

NASA Astrophysics Data System (ADS)

Agnese, C.; Cammalleri, C.; Ciraolo, G.; Minacapilli, M.; Provenzano, G.; Rallo, G.; de Bruin, H. A. R.

2009-09-01

Models to estimate the actual evapotranspiration (ET) in sparse vegetation area can be fundamental for agricultural water managements, especially when water availability is a limiting factor. Models validation must be carried out by considering in situ measurements referred to the field scale, which is the relevant scale of the modelled variables. Moreover, a particular relevance assumes to consider separately the components of plant transpiration (T) and soil evaporation (E), because only the first is actually related to the crop stress conditions. Objective of the paper was to assess a procedure aimed to estimate olive trees actual transpiration by combining sap flow measurements with the scintillometer technique at field scale. The study area, located in Western Sicily (Italy), is mainly cultivated with olive crop and is characterized by typical Mediterranean semi-arid climate. Measurements of sap flow and crop actual evapotranspiration rate were carried out during 2008 irrigation season. Crop transpiration fluxes, measured on some plants by means of sap flow sensors, were upscaled considering the leaf area index (LAI). The comparison between evapotranspiration values, derived by displaced-beam small-aperture scintillometer (DBSAS-SLS20, Scintec AG), with the transpiration fluxes obtained by the sap flow sensors, also allowed to evaluate the contribute of soil evaporation in an area characterized by low vegetation coverage.

REDRAW-Based Evapotranspiration Estimation in Chongli, North China

NASA Astrophysics Data System (ADS)

Zhang, Z.; Wang, Z.

2017-12-01

Evapotranspiration (ET) is the key component of hydrological cycle and spatial estimates of ET are important elements of atmospheric circulation and hydrologic models. Quantifying the ET over large region is significant for water resources planning, hydrologic water balances, water rights management, and water division. In this study, Evapotranspiration (ET) was estimated using REDRAW model in the Chongli on 2014. REDRAW is a satellite-based balance algorithm with reference dry and wet limits model developed to estimate ET. Remote sensing data obtained from MODIS and meteorological data from China Meteorological Data Sharing Service System were used in ET model. In order to analyze the distribution and time variation of ET over the study region, daily, monthly and yearly ET were calculated for the study area, and ET of different land cover types were calculated. In terms of the monthly ET, the figure was low in winter and high in other seasons, and reaches the maximum value in August, showing a high monthly difference. The ET value of water body was the highest and that of barren or sparse vegetation were the lowest, which accorded with local actual condition. Evaluating spatial temporal distribution of actual ET could assist to understand the water consumption regularity in region and figure out the effect from different land cover, which helped to establish links between land use, water allocation, and water use planning in study region. Due to the groundwater recession in north China, the evaluation of regional total water resources become increasingly essential, and the result of this study can be used to plan the water use. As the Chongli will prepare the ski slopes for Winter Olympics on 2022, accuracy estimation of actual ET can efficiently resolve water conflict and relieve water scarcity.

Drought assessment by evapotranspiration mapping in Twente

NASA Astrophysics Data System (ADS)

Eden, U.; Timmermans, J.; van der Velde, R.; Su, Z.

2012-04-01

Drought is a reoccurring worldwide problem with impacts ranging from food production to infrastructure. Droughts are different from other natural hazards (floods, hurricanes, and earthquakes) because the effects can only be witnessed slowly and with a time delay. Effects of droughts are diverse, like famine and migration of people. Droughts are caused by natural causes but also by interaction between the natural events and water demand. Not only typical dry regions, like the Horn of Africa, are affected, but even semi-humid environments, like Europe. Temperature rise and precipitation deficit in the summers of 2003 and 2006 caused substantial crop losses in the agricultural sector in the Netherlands. In addition increased river water temperatures and low water levels caused cooling problems for power plants. Heat waves and prolonged absence of precipitation is expected to increase due to climate change. Therefore assessing and monitoring drought in the Netherlands is thus very important. Various drought indices are available to assess the severity, duration and spatial extend of the drought. Some of the commonly indices used are Standardized precipitation index (SPI) and the Palmer Drought Severity Index (PDSI). However each of these indices do not take into account the actual state of the land surface in respect to the dryness. By analysing drought through actual evapotranspiration (ET) estimations from remote sensing this can be circumvented. The severity of the droughts was quantified by ET-mapping from 2003-2010. The assessment was based on the spatial and temporal distribution of ET using the Evapotranspiration Deficit Index (ETDI) drought index. Surface energy fluxes, like ET, were estimated using WACMOS methodology. The input data consisted of remote sensing products like land surface temperature, LAI, and albedo from MODIS; and meteorological data like air-temperature, humidity and wind speed from the European Centre for Medium weather forecast (ECMWF

Eta Carinae and Its Ejecta, the Homunculus

NASA Technical Reports Server (NTRS)

Gull, Theodore R.

2014-01-01

Eta Carinae (Eta Car), its interacting winds and historical ejecta provide an unique astrophysical laboratory that permits addressing a multitude of questions ranging from stellar evolution, colliding winds, chemical enrichment, nebular excitation to the formation of molecules and dust. Every 5.54 years, Eta Car changes from high excitation to several-months-long low excitation caused by modulation of the massive interacting winds due to a very eccentric binary orbit. The surrounding Homunculus (Figure 1) and Little Homunculus, thrown out in the 1840s Great Eruption and the 1890s Lesser Eruption, respond to the changing flux, providing clues to many physical phenomena of great interest to astrophysicists.

Exploring the use of multi-sensor data fusion for daily evapotranspiration mapping at field scale

USDA-ARS?s Scientific Manuscript database

Modern practices of water management in agriculture can significantly benefit from accurate mapping of crop water consumption at field scale. Assuming that actual evapotranspiration (ET) is the main water loss in land hydrological balance, remote sensing data represent an invaluable tool for water u...

Model Error Estimation for the CPTEC Eta Model

NASA Technical Reports Server (NTRS)

Tippett, Michael K.; daSilva, Arlindo

1999-01-01

Statistical data assimilation systems require the specification of forecast and observation error statistics. Forecast error is due to model imperfections and differences between the initial condition and the actual state of the atmosphere. Practical four-dimensional variational (4D-Var) methods try to fit the forecast state to the observations and assume that the model error is negligible. Here with a number of simplifying assumption, a framework is developed for isolating the model error given the forecast error at two lead-times. Two definitions are proposed for the Talagrand ratio tau, the fraction of the forecast error due to model error rather than initial condition error. Data from the CPTEC Eta Model running operationally over South America are used to calculate forecast error statistics and lower bounds for tau.

Using Remote Sensing to Estimate Crop Water Use to Improve Irrigation Water Management

NASA Astrophysics Data System (ADS)

Reyes-Gonzalez, Arturo

Irrigation water is scarce. Hence, accurate estimation of crop water use is necessary for proper irrigation managements and water conservation. Satellite-based remote sensing is a tool that can estimate crop water use efficiently. Several models have been developed to estimate crop water requirement or actual evapotranspiration (ETa) using remote sensing. One of them is the Mapping EvapoTranspiration at High Resolution using Internalized Calibration (METRIC) model. This model has been compared with other methods for ET estimations including weighing lysimeters, pan evaporation, Bowen Ratio Energy Balance System (BREBS), Eddy Covariance (EC), and sap flow. However, comparison of METRIC model outputs to an atmometer for ETa estimation has not yet been attempted in eastern South Dakota. The results showed a good relationship between ETa estimated by the METRIC model and estimated with atmometer (r2 = 0.87 and RMSE = 0.65 mm day-1). However, ETa values from atmometer were consistently lower than ET a values from METRIC. The verification of remotely sensed estimates of surface variables is essential for any remote-sensing study. The relationships between LAI, Ts, and ETa estimated using the remote sensing-based METRIC model and in-situ measurements were established. The results showed good agreement between the variables measured in situ and estimated by the METRIC model. LAI showed r2 = 0.76, and RMSE = 0.59 m2 m -2, Ts had r2 = 0.87 and RMSE 1.24 °C and ETa presented r2= 0.89 and RMSE = 0.71 mm day -1. Estimation of ETa using energy balance method can be challenging and time consuming. Thus, there is a need to develop a simple and fast method to estimate ETa using minimum input parameters. Two methods were used, namely 1) an energy balance method (EB method) that used input parameters of the Landsat image, weather data, a digital elevation map, and a land cover map and 2) a Kc-NDVI method that use two input parameters: the Landsat image and weather data. A strong

Energy Balance and Evapotranspiration in a High Mountain Area during Summer.

NASA Astrophysics Data System (ADS)

Konzelmann, T.; Calanca, P.; Müller, G.; Menzel, L.; Lang, H.

1997-07-01

A meteorological experiment was carried out in summer 1995 at two representative sites above and below the timberline in the Dischma Valley, near Davos, Switzerland. The study aimed at investigating the characteristics of the surface energy balance and of the evapotranspiration in a high alpine environment during the vegetation period. At both sites, net radiation is the only energy source. It amounts to about 80 W m2 at the lower and 100 W m2 at the upper sites, respectively. Since the albedo and the longwave radiation budget do not differ significantly, net radiation was found to be linearly dependent on global radiation. The latent heat flux associated with evapotranspiration represents the most important energy sink, averaging to 70 W m2 at the lower and 63 W m2 at the upper locations. It is therefore of comparable magnitude, despite a larger energy availability at the upper site. This is due to a significantly larger Bowen ratio at this upper location. On the other hand, the diurnal course of the Bowen ratio is at both sites such that the latent heat flux can be expressed as a linear function of net or global radiation. For a better characterization, the actual evapotranspiration was compared to Penman's parameterization, which represents the potential limit for saturated surface conditions. The comparison shows that, even during wet periods, evapotranspiration is regulated by the moisture conditions in the soil and the physiological behavior of vegetation.

Gravity Chromatic Imaging of the Eta Car's Core

NASA Astrophysics Data System (ADS)

Sanchez-Bermudez, Joel

2018-04-01

Eta Car is one of the most massive, and intriguing, Luminous Blue Variables known. In its core resides a binary with a 5.54 years orbital period. Visible, infrared, and X-raobservations suggest that the primary star exhibits a very dense wind with a terminal velocity of about 420 km/s, while the secondary shows a much faster and less dense wind with a terminal velocity of 3000 km/s. The wind-wind collision zone at the core of Eta Car is thus a complex region that deserves a detailed study to understand the effect of the binary interaction in the evolution of the system. Here, we will present a unique imaging campaign with GRAVITY/VLTI of the Eta Car's core. The superb quality of our interferometric data, together with state-of-the-art image reconstruction techniques, allowed us to obtain, with milliarcsecond resolution, continuum and chromatic images cross the BrG and HeI lines in the Eta Car K-band spectrum (R 4000). These new data together with models of the primary wind of Eta Car has letting us to characterize the spatial distribution of the dust and gas in the inner 40 AU wind-wind collision zone of the target.

Image of the Eta Carinae Nebula Taken by the High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1979-01-01

This image is an x-ray view of Eta Carinae Nebula showing bright stars taken with the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. The Eta Carinae Nebula is a large and complex cloud of gas, crisscrossed with dark lanes of dust, some 6,500 light years from Earth. Buried deep in this cloud are many bright young stars and a very peculiar variable star. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

Application of SEBAL approach and MODIS time-series to map vegetation water use patterns in the data scarce Krishna river basin of India.

PubMed

Ahmad, M D; Biggs, T; Turral, H; Scott, C A

2006-01-01

Evapotranspiration (ET) from irrigated land is one of the most useful indicators to explain whether the water is used as "intended". In this study, the Surface Energy Balance Algorithm for Land (SEBAL) was used to compute actual ET from a Landsat7 image of December 29, 2000 for diverse land use in the Krishna Basin in India. SEBAL ETa varies between 0 to 4.7 mm per day over the image and was quantified for identified land use classes. Seasonal/annual comparison of ETa from different land uses requires time series images, processed by SEBAL. In this study, the Landsat-derived snapshot SEBAL ETa result was interpreted using the cropping calendar and time series analysis of MODIS imagery. The wastewater irrigated area in the basin has the highest ETa in the image, partly due to its advanced growth stage compared to groundwater-irrigated rice. Shrub and forests in the senescence phase have similar ETa to vegetable/cash crops, and ETa from grasslands is a low 0.8 mm per day after the end of the monsoon. The results indicate that wastewater irrigation of fodder and rice is sufficient to meet crop water demand but there appears to be deficit irrigation of rice using groundwater.

Evapotranspiration Cycles in a High Latitude Agroecosystem: Potential Warming Role.

PubMed

Ruairuen, Watcharee; Fochesatto, Gilberto J; Sparrow, Elena B; Schnabel, William; Zhang, Mingchu; Kim, Yongwon

2015-01-01

As the acreages of agricultural lands increase, changes in surface energetics and evapotranspiration (ET) rates may arise consequently affecting regional climate regimes. The objective of this study was to evaluate summertime ET dynamics and surface energy processes in a subarctic agricultural farm in Interior Alaska. The study includes micrometeorological and hydrological data. Results covering the period from June to September 2012 and 2013 indicated consistent energy fractions: LE/Rnet (67%), G/Rnet (6%), H/Rnet (27%) where LE is latent heat flux, Rnet is the surface net radiation, G is ground heat flux and H is the sensible heat flux. Additionally actual surface evapotranspiration from potential evaporation was found to be in the range of 59 to 66%. After comparing these rates with those of most prominent high latitude ecosystems it is argued here that if agroecosystem in high latitudes become an emerging feature in the land-use, the regional surface energy balance will significantly shift in comparison to existing Arctic natural ecosystems.

Application of a CROPWAT Model to Analyze Crop Yields in Nicaragua

NASA Astrophysics Data System (ADS)

Doria, R.; Byrne, J. M.

2013-12-01

ABSTRACT Changes in climate are likely to influence crop yields due to varying evapotranspiration and precipitation over agricultural regions. In Nicaragua, agriculture is extensive, with new areas of land brought into production as the population increases. Nicaraguan staple food items (maize and beans) are produced mostly by small scale farmers with less than 10 hectares, but they are critical for income generation and food security for rural communities. Given that the majority of these farmers are dependent on rain for crop irrigation, and that maize and beans are sensitive to variations in temperature and rainfall patterns, the present study was undertaken to assess the impact of climate change on these crop yields. Climate data were generated per municipio representing the three major climatic zones of the country: the wet Pacific lowland, the cooler Central highland, and the Caribbean lowland. Historical normal climate data from 1970-2000 (baseline period) were used as input to CROPWAT model to analyze the potential and actual evapotranspiration (ETo and ETa, respectively) that affects crop yields. Further, generated local climatic data of future years (2030-2099) under various scenarios were inputted to the CROPWAT to determine changes in ETo and ETa from the baseline period. Spatial variability maps of both ETo and ETa as well as crop yields were created. Results indicated significant variation in seasonal rainfall depth during the baseline period and predicted decreasing trend in the future years that eventually affects yields. These maps enable us to generate appropriate adaptation measures and best management practices for small scale farmers under future climate change scenarios. KEY WORDS: Climate change, evapotranspiration, CROPWAT, yield, Nicaragua

WFPC2 Image of the Variable Star Eta Carinae

NASA Image and Video Library

2016-01-06

The discovery of likely Eta Carinae twins in other galaxies will help scientists better understand this brief phase in the life of a massive star with images such as this from NASA Hubble Space Telescope. Astronomers cannot yet explain what caused the titanic eruption of star Eta Carinae in the 1840s. The discovery of likely Eta Carinae "twins" in other galaxies will help scientists better understand this brief phase in the life of a massive star. http://photojournal.jpl.nasa.gov/catalog/PIA20294

Evapotranspiration and microclimate at a low-level radioactive-waste disposal site in northwestern Illinois

USGS Publications Warehouse

Healy, R.W.; DeVries, M.P.; Sturrock, Alex M.

1989-01-01

From July 1982 through June 1984, a study was made of the evapotranspiration and microclimate at a low-level radioactive-waste disposal site near Sheffield, Bureau County, Illinois. Vegetation at the site consists of mixed pasture grasses, primarily awnless brome (Bromus inermis) and red clover (Trifoleum pratense). Three methods were used to estimate evapotranspiration: (1) an energy budget with the Bowen ratio, (2) an aerodynamic profile, and (3) a soil-based water budget. For the aerodynamic-profile method, sensible-heat flux was estimated by a profile equation and evapotranspiration was then calculated as the residual in the energy-balance equation. Estimates by the energy-budget and aerodynamic-profile methods were computed from hourly data and then summed by days and months. Yearly estimates (for March through November) by these methods were in close agreement: 648 and 626 millimeters, respectively. Daily estimates reach a maximum of about 6 millimeters. The water-budget method produced only monthly estimates based on weekly or biweekly soil-moisture content measurements. The yearly evapotranspiration estimated by this method (which actually included only the months of April through October) was 655 millimeters. The March-through-November average for the three methods of 657 millimeters was equivalent to 70 percent of total precipitation. Continuous measurements were made of incoming and reflected shortwave radiation, incoming and emitted longwave radiation, net radiation, soil-heat flux, soil temperature, horizontal windspeed, and wet- and dry-bulb air temperature. Windspeed and air temperature were measured at heights of 0.5 and 2.0 meters (and also at 1.0 meter after September 1983). Soilmoisture content of the soil zone was measured with a gamma-attenuation gage. Annual precipitation (938 millimeters) and average temperature (10.8 degrees Celsius) at the Sheffield site were virtually identical to long-term averages from nearby National Weather Service

Measurement of the transition form factor of {eta} meson with WASA-at-COSY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhatt, H.

2011-10-24

Reaction {eta}{yields}e{sup +}e{sup -}{gamma} is used to investigate the transition form factor of {eta} meson with WASA detector at COSY. Where the {eta} meson is produced in pp collision at 1.4 GeV. We present the analysis techniques and preliminary results of {eta} Dalitz decays.

Search for {eta}-mesic helium using WASA-at-COSY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moskal, P.; Institut fuer Kernphysik and Juelich Center for Hadron Physics, Forschungszentrum Juelich, Juelich

2010-08-05

The installation of the WASA detector at the cooler synchrotron COSY opened the possibility to search for {eta}-mesic helium with high statistics and high acceptance. A search for the {sup 4}He--{eta} bound state is conducted via an exclusive measurement of the excitation function for the dd{yields}{sup 3}Hep{pi}{sup -} reaction varying continuously the beam momentum around the threshold for the dd{yields}{sup 4}He{eta} reaction. Ramping of the beam momentum and taking advantage of the large acceptance of the WASA detector allows to minimize systematical uncertainities.

Evaluation from 3-Years Time Serie of Daily Actual Evapotranspiration over the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Faivre, R.; Menenti, M.

2016-08-01

The estimation of turbulent uxes is of primary interest for hydrological and climatological studies. Also the use of optical remote sensing data in the VNIR and TIR domain already proved to allow for the parameterization of surface energy balance, leading to many algorithms. Their use over arid high elevation areas require detailed characterisation of key surface physical properties and atmospheric statement at a reference level. Satellite products aquired over the Tibetan Plateau and simulations results delivered in the frame of the CEOP-AEGIS project provide incentives for a regular analysis at medium scale.This work aims at evaluating the use Feng-Yun 2 series and MODIS data (VNIR and TIR) for land surface evapotranspiration (ET) daily mapping based on SEBI algorithm, over the whole Tibetan Plateau (Faivre, 2014). An evaluation is performed over some reference sites set-up through the Tibetan Plateau.

Conversations with Early Leaders of Eta Sigma Gamma

ERIC Educational Resources Information Center

Clark, Jeffrey K.; Seabert, Denise M.; Goldsmith, Mal

2007-01-01

Anniversaries are often a time to reflect on the past. With that in mind, interviews were conducted with early key leaders of Eta Sigma Gamma to explore their perspectives of the organization's growth and development as well as their hopes for the future of ESG. The individuals interviewed included the surviving founders of Eta Sigma Gamma, the…

Dominant effect of increasing forest biomass on evapotranspiration: interpretations of movement in Budyko space

NASA Astrophysics Data System (ADS)

Jaramillo, Fernando; Cory, Neil; Arheimer, Berit; Laudon, Hjalmar; van der Velde, Ype; Hasper, Thomas B.; Teutschbein, Claudia; Uddling, Johan

2018-01-01

During the last 6 decades, forest biomass has increased in Sweden mainly due to forest management, with a possible increasing effect on evapotranspiration. However, increasing global CO2 concentrations may also trigger physiological water-saving responses in broadleaf tree species, and to a lesser degree in some needleleaf conifer species, inducing an opposite effect. Additionally, changes in other forest attributes may also affect evapotranspiration. In this study, we aimed to detect the dominating effect(s) of forest change on evapotranspiration by studying changes in the ratio of actual evapotranspiration to precipitation, known as the evaporative ratio, during the period 1961-2012. We first used the Budyko framework of water and energy availability at the basin scale to study the hydroclimatic movements in Budyko space of 65 temperate and boreal basins during this period. We found that movements in Budyko space could not be explained by climatic changes in precipitation and potential evapotranspiration in 60 % of these basins, suggesting the existence of other dominant drivers of hydroclimatic change. In both the temperate and boreal basin groups studied, a negative climatic effect on the evaporative ratio was counteracted by a positive residual effect. The positive residual effect occurred along with increasing standing forest biomass in the temperate and boreal basin groups, increasing forest cover in the temperate basin group and no apparent changes in forest species composition in any group. From the three forest attributes, standing forest biomass was the one that could explain most of the variance of the residual effect in both basin groups. These results further suggest that the water-saving response to increasing CO2 in these forests is either negligible or overridden by the opposite effect of the increasing forest biomass. Thus, we conclude that increasing standing forest biomass is the dominant driver of long-term and large-scale evapotranspiration

Evidence for B{yields}K{eta}'{gamma} decays at Belle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wedd, R.; Barberio, E.; Limosani, A.

2010-06-01

We present the results of a search for the radiative decay B{yields}K{eta}{sup '{gamma}} and find evidence for B{sup +{yields}}K{sup +{eta}'{gamma}} decays at the 3.3 standard deviation level with a partial branching fraction of (3.6{+-}1.2{+-}0.4)x10{sup -6}, where the first error is statistical and the second systematic. This measurement is restricted to the region of combined K{eta}{sup '} invariant mass less than 3.4 GeV/c{sup 2}. A 90% confidence level upper limit of 6.4x10{sup -6} is obtained for the partial branching fraction of the decay B{sup 0{yields}}K{sup 0{eta}'{gamma}} in the same K{eta}{sup '} invariant mass region. These results are obtained from a 605more » fb{sup -1} data sample containing 657x10{sup 6}BB pairs collected at the {Upsilon}(4S) resonance with the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider.« less

Evapotranspiration from the Lower Walker River Basin, West-Central Nevada, Water Years 2005-07

USGS Publications Warehouse

Allander, Kip K.; Smith, J. LaRue; Johnson, Michael J.

2009-01-01

evapotranspiration station in a saltcedar grove, measurements indicated a possible decrease in evapotranspiration of about 50 percent due to defoliation of the saltcedar by the saltcedar leaf beetle. Total evapotranspiration from the evapotranspiration units identified in the Lower Walker River basin was about 231,000 acre-feet per year (acre-ft/yr). Of this amount, about 45,000 acre-ft/yr originated from direct precipitation, resulting in net evapotranspiration of about 186,000 acre-ft/yr. More than 80 percent of net evapotranspiration in the Lower Walker River basin was through evaporation from Walker Lake. Total evaporation from Walker Lake was about 161,000 acre-ft/yr and net evaporation was about 149,000 acre-ft/yr. Some previous estimates of evaporation from Walker Lake based on water-budget analysis actually represent total evaporation minus ground-water inflow to the lake. Historical evaporation rates determined on the basis of water budget analysis were less than the evaporation rate measured directly during this study. The difference could represent ground-water inflow to Walker Lake of 16,000 to 26,000 acre-ft/yr or could indicate that ground-water inflow to Walker Lake is decreasing over time as the lake perimeter recedes.

Concerning the relationship between evapotranspiration and soil moisture

NASA Technical Reports Server (NTRS)

Wetzel, Peter J.; Chang, Jy-Tai

1987-01-01

The relationship between the evapotranspiration and soil moisture during the drying, supply-limited phase is studied. A second scaling parameter, based on the evapotranspirational supply and demand concept of Federer (1982), is defined; the parameter, referred to as the threshold evapotranspiration, occurs in vegetation-covered surfaces just before leaf stomata close and when surface tension restricts moisture release from bare soil pores. A simple model for evapotranspiration is proposed. The effects of natural soil heterogeneities on evapotranspiration computed from the model are investigated. It is observed that the natural variability in soil moisture, caused by the heterogeneities, alters the relationship between regional evapotranspiration and the area average soil moisture.

Latitude-Dependent Effects in the Stellar Wind of Eta Carinae

NASA Technical Reports Server (NTRS)

Smith, Nathan; Davidson, Kris; Gull, Theodore R.; Ishibashi, Kazunori; Hillier, D. John

2002-01-01

The Homunculus reflection nebula around eta Carinae provides the rare opportunity to observe the spectrum of a star from more than one direction. In the case of eta Car, the nebula's geometry is known well enough to infer how wind profiles vary with latitude. We present STIS spectra of several positions in the Homunculus, showing directly that eta Car has an aspherical and axisymmetric stellar wind. P Cygni absorption in Balmer lines depends on latitude, with relatively high velocities and strong absorption near the polar axis. Stronger absorption at high latitudes is surprising, and it suggests higher mass flux toward the poles, perhaps resulting from equatorial gravity darkening on a rotating star. Reflected profiles of He I lines are more puzzling, and offer clues to eta Car's wind geometry and ionization structure. During eta Car's high-excitation state in March 2000, the wind had a fast, dense polar wind, with higher ionization at low latitudes. Older STIS data obtained since 1998 reveal that this global stellar-wind geometry changes during eta Car's 5.5 year cycle, and may suggest that this star s spectroscopic events are shell ejections. Whether or not a companion star triggers these outbursts remains ambiguous. The most dramatic changes in the wind occur at low latitudes, while the dense polar wind remains relatively undisturbed during an event. The apparent stability of the polar wind also supports the inferred bipolar geometry. The wind geometry and its variability have critical implications for understanding the 5.5 year cycle and long-term variability, but do not provide a clear alternative to the binary hypothesis for generating eta Car s X-rays.

Characteristics and Impact Factors of Parameter Alpha in the Nonlinear Advection-Aridity Method for Estimating Evapotranspiration at Interannual Scale in the Loess Plateau

NASA Astrophysics Data System (ADS)

Zhou, H.; Liu, W.; Ning, T.

2017-12-01

Land surface actual evapotranspiration plays a key role in the global water and energy cycles. Accurate estimation of evapotranspiration is crucial for understanding the interactions between the land surface and the atmosphere, as well as for managing water resources. The nonlinear advection-aridity approach was formulated by Brutsaert to estimate actual evapotranspiration in 2015. Subsequently, this approach has been verified, applied and developed by many scholars. The estimation, impact factors and correlation analysis of the parameter alpha (αe) of this approach has become important aspects of the research. According to the principle of this approach, the potential evapotranspiration (ETpo) (taking αe as 1) and the apparent potential evapotranspiration (ETpm) were calculated using the meteorological data of 123 sites of the Loess Plateau and its surrounding areas. Then the mean spatial values of precipitation (P), ETpm and ETpo for 13 catchments were obtained by a CoKriging interpolation algorithm. Based on the runoff data of the 13 catchments, actual evapotranspiration was calculated using the catchment water balance equation at the hydrological year scale (May to April of the following year) by ignoring the change of catchment water storage. Thus, the parameter was estimated, and its relationships with P, ETpm and aridity index (ETpm/P) were further analyzed. The results showed that the general range of annual parameter value was 0.385-1.085, with an average value of 0.751 and a standard deviation of 0.113. The mean annual parameter αe value showed different spatial characteristics, with lower values in northern and higher values in southern. The annual scale parameter linearly related with annual P (R2=0.89) and ETpm (R2=0.49), while it exhibited a power function relationship with the aridity index (R2=0.83). Considering the ETpm is a variable in the nonlinear advection-aridity approach in which its effect has been incorporated, the relationship of

Evapotranspiration Cycles in a High Latitude Agroecosystem: Potential Warming Role

PubMed Central

Ruairuen, Watcharee

2015-01-01

As the acreages of agricultural lands increase, changes in surface energetics and evapotranspiration (ET) rates may arise consequently affecting regional climate regimes. The objective of this study was to evaluate summertime ET dynamics and surface energy processes in a subarctic agricultural farm in Interior Alaska. The study includes micrometeorological and hydrological data. Results covering the period from June to September 2012 and 2013 indicated consistent energy fractions: LE/R net (67%), G/R net (6%), H/R net (27%) where LE is latent heat flux, R net is the surface net radiation, G is ground heat flux and H is the sensible heat flux. Additionally actual surface evapotranspiration from potential evaporation was found to be in the range of 59 to 66%. After comparing these rates with those of most prominent high latitude ecosystems it is argued here that if agroecosystem in high latitudes become an emerging feature in the land-use, the regional surface energy balance will significantly shift in comparison to existing Arctic natural ecosystems. PMID:26368123

Interaction of eta mesons with nuclei.

PubMed

Kelkar, N G; Khemchandani, K P; Upadhyay, N J; Jain, B K

2013-06-01

Back in the mid-1980s, a new branch of investigation related to the interaction of eta mesons with nuclei came into existence. It started with the theoretical prediction of possible exotic states of eta mesons and nuclei bound by the strong interaction and later developed into an extensive experimental program to search for such unstable states as well as understand the underlying interaction via eta-meson producing reactions. The vast literature of experimental as well as theoretical works that studied various aspects of eta-producing reactions such as the π(+)n → ηp, pd → (3)Heη, p (6)Li → (7)Be η and γ (3)He → η X, to name a few, had but one objective in mind: to understand the eta-nucleon (ηN) and hence the η-nucleus interaction which could explain the production data and confirm the existence of some η-mesic nuclei. In spite of these efforts, there remain uncertainties in the knowledge of the ηN and hence the η-nucleus interaction. Therefore, this review is an attempt to bind together the findings in these works and draw some global and specific conclusions which can be useful for future explorations.The ηN scattering length (which represents the strength of the η-nucleon interaction) using different theoretical models and analyzing the data on η production in pion, photon and proton induced reactions was found to be spread out in a wide range, namely, 0.18 ≤ Re aηN ≤ 1.03 fm and 0.16 ≤ Rm aηN ≤ 0.49 fm. Theoretical searches of heavy η-mesic nuclei based on η-nucleus optical potentials and lighter ones based on Faddeev type few-body approaches predict the existence of several quasibound and resonant states. Although some hints of η-mesic states such as (3)(η)He and (25)(η)Mg do exist from previous experiments, the promise of clearer signals for the existence of η-mesic nuclei lies in the experiments to be performed at the J-PARC, MAMI and COSY facilities in the near future. This review is aimed at giving an overall status

Evapotranspiration and microclimate at a low-level radioactive-waste disposal site in northwestern Illinois

USGS Publications Warehouse

Healy, R.W.; DeVries, M.P.; Sturrock, A.M.

1987-01-01

From July 1982 through June 1984, a study was made of the microclimate and evapotranspiration at a low-level radioactive-waste disposal site near Sheffield, Bureau County, Illinois. Vegetation at the site consists of mixed pasture grasses, primarily brome (Bromus inermis) and red clover (Trifoleum pratense). Three methods were used to estimate evapotranspiration: (1) an energy-budget with the Bowen ratio, (2) an aerodynamic-profile, and (3) a soil-based water-budget. For the aerodynamic-profile method, sensible-heat flux was estimated by a profile equation and evapotranspiration was then calculated as the residual in the energy-balance equation. Estimates by the energy-budget and aerodynamic-profile methods were computed from hourly data, then summed by days and months. Yearly estimates for March through November, by these methods, were quite close--648 and 626 millimeters, respectively. Daily estimates range up to a maximum of about 6 millimeters. The water-budget method produced only monthly estimates based on weekly or biweekly soil-moisture content measurements. The yearly evapotranspiration estimated by this method (which actually included only the months of April through October) was 655 millimeters. The March-through-November average for the three methods of 657 millimeters was equivalent to 70 percent of precipitation. Continuous measurements were made of incoming and reflected shortwave radiation, incoming and emitted longwave radiation, net radiation, soil-heat flux, soil temperature, horizontal windspeed, and wet- and dry-bulb air temperature. Windspeed and air temperature were measured at heights of 0.5 and 2.0 meters (and also at 1.0 meter after September 1983). Soil-moisture content of the soil zone was measured with a gamma-attenuation gage. Annual precipitation (938 millimeters) and average temperature (10.8 degrees Celsius) were virtually identical to long-term averages from nearby National Weather Service stations. Solar radiation averaged 65

The Character and Variability of the Eta Carinae Wind Lines

NASA Technical Reports Server (NTRS)

Nielsen, K. E.; Corcoran, M. F.; Gull, T. R.; Ivarsson, S.; Hillier, J. D.

2006-01-01

The binarity of Eta Carinae has been debated for a long time. We have searched for more evidence for a companion star in a spectroscopic investigation of the Eta Carinae stellar wind lines, using moderate spectral and high angular resolution HST/STIS data. Over Eta Carinae's 5.54 year spectroscopic period many of the observable wind lines in the NUV/Optical spectral region exhibit peculiar line profiles with unusual velocity shifts relative to the system velocity. Some of the lines are exclusively blue-shifted over the entire cycle. Their ionization/excitation imply formation not in the stellar wind but rather in the interface between the two massive stars. We have analyzed velocity and intensity variations over the spectroscopic period and interpreted what the variations tell us about the geometry of the nebular structure close to Eta Carinae.

76 FR 386 - Proposed Information Collection Request for the ETA 586, Interstate Arrangement for Combining...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-04

... DEPARTMENT OF LABOR Proposed Information Collection Request for the ETA 586, Interstate... extension of the report for the Interstate Arrangement for Combining Employment and Wages, Form ETA 586. A... under the CWC arrangement. The ETA 586 report provides the ETA/Office of Workforce Security with...

Scaled-up dual anode/cathode microbial fuel cell stack for actual ethanolamine wastewater treatment.

PubMed

An, Byung-Min; Heo, Yoon; Maitlo, Hubdar-Ali; Park, Joo-Yang

2016-06-01

The aim of this work was to develop the scale-up microbial fuel cell technology for actual ethanolamine wastewater treatment, dual anode/cathode MFC stacks connected in series to achieve any desired current, treatment capacity, and volume capacity. However, after feeding actual wastewater into the MFC, maximum power density decreased while the corresponding internal resistance increased. With continuous electricity production, a stack of eight MFCs in series achieved 96.05% of COD removal and 97.30% of ammonia removal at a flow rate of 15.98L/d (HRT 12h). The scaled-up dual anode/cathode MFC stack system in this research was demonstrated to treat actual ETA wastewater with the added benefit of harvesting electricity energy. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Citizen's Guide to Evapotranspiration Covers

EPA Pesticide Factsheets

This guide explains Evapotranspiration Covers which are Evapotranspiration (ET) covers are a type of cap placed over contaminated material, such as soil, landfill waste, or mining tailings, to prevent water from reaching it.

New ruthenium carboxylate complexes having a 1-5-. eta. sup 5 -cyclooctadienyl ligand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Osakada, Kohtaro; Grohmann, A.; Yamamoto, Akio

1990-07-01

Reaction of 3-butenoic acid with Ru(cod)(cot) (cod) = 1-2-{eta}{sup 2}:5-6-{eta}{sup 2}-cyclooctadiene; cot = 1-6-{eta}{sup 6}-cyclooctatriene in the presence of PMe{sub 3} gives a new ruthenium(II) complex formulated as Ru(1-5-{eta}{sup 5}-C{sub 8}H{sub 11}){eta}{sup 1}(O),{eta}{sup 2}(C,C{prime}-OCOCH{sub 2}CH{double bond}CH{sub 2})(PMe{sub 3}) (1). X-ray crystallography revealed its structure as having a piano-stool coordination around the ruthenium center. Crystals of 1 are tetragonal, space group P4{sub 3}2{sub 1}2, with a = 12.559 (3) {angstrom}, c = 20.455 (4) {angstrom}, and Z = 8. {sup 1}H and {sup 13}C({sup 1}H) NMR spectra of 1 agree well for the structure with the allyl entity of the carboxylatemore » {pi}-bonded through the C{double bond}C double bond to ruthenium.« less

Structural basis for the suppression of skin cancers by DNA polymerase [eta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silverstein, Timothy D.; Johnson, Robert E.; Jain, Rinku

2010-09-13

DNA polymerase {eta} (Pol{eta}) is unique among eukaryotic polymerases in its proficient ability for error-free replication through ultraviolet-induced cyclobutane pyrimidine dimers, and inactivation of Pol{eta} (also known as POLH) in humans causes the variant form of xeroderma pigmentosum (XPV). We present the crystal structures of Saccharomyces cerevisiae Pol{eta} (also known as RAD30) in ternary complex with a cis-syn thymine-thymine (T-T) dimer and with undamaged DNA. The structures reveal that the ability of Pol{eta} to replicate efficiently through the ultraviolet-induced lesion derives from a simple and yet elegant mechanism, wherein the two Ts of the T-T dimer are accommodated in anmore » active site cleft that is much more open than in other polymerases. We also show by structural, biochemical and genetic analysis that the two Ts are maintained in a stable configuration in the active site via interactions with Gln55, Arg73 and Met74. Together, these features define the basis for Pol{eta}'s action on ultraviolet-damaged DNA that is crucial in suppressing the mutagenic and carcinogenic consequences of sun exposure, thereby reducing the incidence of skin cancers in humans.« less

Recurrent X-ray Emission Variations of Eta Carinae and the Binary Hypothesis

NASA Technical Reports Server (NTRS)

Ishibashi, K.; Corcoran, M. F.; Davidson, K.; Swank, J. H.; Petre, R.; Drake, S. A.; Damineki, A.; White, S.

1998-01-01

Recent studies suggest that, the super-massive star eta Carinae may have a massive stellar companion (Damineli, Conti, and Lopes 1997), although the dense ejecta surrounding the star make this claim hard to test using conventional methods. Settling this question is critical for determining the current evolutionary state and future evolution of the star. We address this problem by an unconventional method: If eta Carinae is a binary, X-ray emission should be produced in shock waves generated by wind-wind collisions in the region between eta Carinae and its companion. Detailed X-ray monitoring of eta Carinae for more that) 2 years shows that the observed emission generally resembles colliding-wind X-ray emission, but with some significant discrepancies. Furthermore, periodic X-ray "flaring" may provide an additional clue to determine the presence of a companion star and for atmospheric pulsation in eta Carinae.

NOAA AVHRR and its uses for rainfall and evapotranspiration monitoring

NASA Technical Reports Server (NTRS)

Kerr, Yann H.; Imbernon, J.; Dedieu, G.; Hautecoeur, O.; Lagouarde, J. P.

1989-01-01

NOAA-7 Advanced Very High Resolution Radiometer (AVHRR) Global Vegetation Indices (GVI) were used during the 1986 rainy season (June-September) over Senegal to monitor rainfall. The satellite data were used in conjunction with ground-based measurements so as to derive empirical relationships between rainfall and GVI. The regression obtained was then used to map the total rainfall corresponding to the growing season, yielding good results. Normalized Difference Vegetation Indices (NDVI) derived from High Resolution Picture Transmission (HRPT) data were also compared with actual evapotranspiration (ET) data and proved to be closely correlated with it with a time lapse of 20 days.

Spatially distributed potential evapotranspiration modeling and climate projections.

PubMed

Gharbia, Salem S; Smullen, Trevor; Gill, Laurence; Johnston, Paul; Pilla, Francesco

2018-08-15

Evapotranspiration integrates energy and mass transfer between the Earth's surface and atmosphere and is the most active mechanism linking the atmosphere, hydrosphsophere, lithosphere and biosphere. This study focuses on the fine resolution modeling and projection of spatially distributed potential evapotranspiration on the large catchment scale as response to climate change. Six potential evapotranspiration designed algorithms, systematically selected based on a structured criteria and data availability, have been applied and then validated to long-term mean monthly data for the Shannon River catchment with a 50m 2 cell size. The best validated algorithm was therefore applied to evaluate the possible effect of future climate change on potential evapotranspiration rates. Spatially distributed potential evapotranspiration projections have been modeled based on climate change projections from multi-GCM ensembles for three future time intervals (2020, 2050 and 2080) using a range of different Representative Concentration Pathways producing four scenarios for each time interval. Finally, seasonal results have been compared to baseline results to evaluate the impact of climate change on the potential evapotranspiration and therefor on the catchment dynamical water balance. The results present evidence that the modeled climate change scenarios would have a significant impact on the future potential evapotranspiration rates. All the simulated scenarios predicted an increase in potential evapotranspiration for each modeled future time interval, which would significantly affect the dynamical catchment water balance. This study addresses the gap in the literature of using GIS-based algorithms to model fine-scale spatially distributed potential evapotranspiration on the large catchment systems based on climatological observations and simulations in different climatological zones. Providing fine-scale potential evapotranspiration data is very crucial to assess the dynamical

Start of Eta Car's X-ray Minimum

NASA Technical Reports Server (NTRS)

Corcoran, Michael F.; Liburd, Jamar; Hamaguchi, Kenji; Gull, Theodore; Madura, Thomas; Teodoro, Mairan; Moffat, Anthony; Richardson, Noel; Russell, Chris; Pollock, Andrew;

An Improved Statistical Solution for Global Seismicity by the HIST-ETAS Approach

NASA Astrophysics Data System (ADS)

Chu, A.; Ogata, Y.; Katsura, K.

2010-12-01

For long-term global seismic model fitting, recent work by Chu et al. (2010) applied the spatial-temporal ETAS model (Ogata 1998) and analyzed global data partitioned into tectonic zones based on geophysical characteristics (Bird 2003), and it has shown tremendous improvements of model fitting compared with one overall global model. While the ordinary ETAS model assumes constant parameter values across the complete region analyzed, the hierarchical space-time ETAS model (HIST-ETAS, Ogata 2004) is a newly introduced approach by proposing regional distinctions of the parameters for more accurate seismic prediction. As the HIST-ETAS model has been fit to regional data of Japan (Ogata 2010), our work applies the model to describe global seismicity. Employing the Akaike's Bayesian Information Criterion (ABIC) as an assessment method, we compare the MLE results with zone divisions considered to results obtained by an overall global model. Location dependent parameters of the model and Gutenberg-Richter b-values are optimized, and seismological interpretations are discussed.

Eta photoproduction in a combined analysis of pion- and photon-induced reactions

DOE PAGES

Ronchen, D.; Doring, M.; Haberzettl, H.; ...

2015-06-25

Themore » $$\\eta N$$ final state is isospin-selective and thus provides access to the spectrum of excited nucleons without being affected by excited $$\\Delta$$ states. To this end, the world database on eta photoproduction off the proton up to a center-of-mass energy of $$E\\sim 2.3$$ GeV is analyzed, including data on differential cross sections, and single and double polarization observables. resonance spectrum and its properties are determined in a combined analysis of eta and pion photoproduction off the proton together with the reactions $$\\pi N\\to \\pi N$$, $$\\eta N$$, $$K\\Lambda$$ and $$K\\Sigma$$. For the analysis, the so-called J\\"ulich coupled-channel framework is used, incorporating unitarity, analyticity, and effective three-body channels. Parameters tied to photoproduction and hadronic interactions are varied simultaneously. Furthermore, the influence of recent MAMI $T$ and $F$ asymmetry data on the eta photoproduction amplitude is discussed in detail.« less

Magnetic eta index and the ability to forecast sporadic E layer appearance

NASA Astrophysics Data System (ADS)

Dziak-Jankowska, Beata; Stanislawska, Iwona; Pozoga, Mariusz; Tomasik, Lukasz; Ernst, Tomasz

2012-07-01

We analysed the correlation of the changes of the magnetic vertical component with the ionospheric deviations from monthly median of the E layer characteristics. Promising results indicate that the eta parameter can be used to predict sporadic E layer during magnetically quiet days. Our previous work concern the data from only one year - 2004. During the descending phase of solar cycle in 2004 there was not numerous amount of quiet days. We extend our research to other years starting from 1996 and focusing on 2007 - 2009, years of the prolonged solar minimum. The analysis shows that under magnetically quiet circumstances the magnetic index eta indicates large magnetic disturbance, especially in vertical component when other magnetic indices inform about quiet magnetic conditions. The results indicate that the increase of the magnetic eta index (the ratio of the variations of vertical component of the external magnetic field to the horizontal component) is associated with the emergence of sporadic E layer or with increase of foEs critical frequency of sporadic E layer. The appearance of sporadic E layer followed 1-2 h after growth of magnetic index eta. An important conclusion is that the analysis of the hourly ionospheric data does not give 100% correlation between the increase of eta and the emergence of Es layer, however, studies of dense measurement data show that the correlation is almost 100%. An advantage of the eta index is the fact that after eliminating the effect of currents induced within the Earth, eta index bring independent and meaningful information on the system of current in the ionosphere. Hence, the eta index could be an important element of the ionosphere monitoring and can be used to predict such local phenomenon like the appearance of the sporadic E layer.

Enzyme-Treated Asparagus Extract (ETAS) Facilitates the Turnover of UV-B-Irradiated Keratinocytes.

PubMed

Koda, Tomoko; Shirato, Ken; Takanari, Jun; Imai, Hideki

2018-01-01

Enzyme-treated asparagus extract (ETAS) is prepared from the lower, residual parts of asparagus, and some functionalities, such as anti-oxidative and neuroprotective activities, have been suggested. The purpose of the present study was to investigate the effects of ETAS on photoaging in the epidermal layer of the skin using cultured keratinocytes. Normal human epidermal keratinocytes were irradiated or left unirradiated with UV-B (10 mJ/cm 2 ) and incubated with ETAS (0.5 or 2 mg/mL) or vehicle. After 3 or 13 h, molecular examinations were performed, and after 24 or 48 h, cell viabilities were determined by a CCK-8 assay. ETAS addition may induce keratinocyte migration and proliferation as well as apoptosis under molecular examination. These results suggest that ETAS might accelerate turnover of keratinocytes.

75 FR 53982 - Proposed Information Collection Request of the ETA 207, Nonmonetary Determination Activities...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-02

... of the ETA 207, Nonmonetary Determination Activities Report; Comment Request on Extension Without... ETA 207 Report, Nonmonetary Determination Activities, contains state data on the number and types of... ETA 207, Nonmonetary Determinations Activities Report. Comments are requested to: * Evaluate whether...

78 FR 40194 - Proposed Information Collection Request of the ETA 207, Nonmonetary Determination Activities...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-03

... of the ETA 207, Nonmonetary Determination Activities Report; Comment Request on Extension Without.... Background The ETA 207 Report, Nonmonetary Determination Activities, contains state data on the number and... proposed extension collection of the ETA 207, Nonmonetary Determinations Activities Report. Comments are...

77 FR 2088 - Information Collection Request for the ETA 9128, Reemployment and Eligibility Assessments...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-13

... DEPARTMENT OF LABOR Information Collection Request for the ETA 9128, Reemployment and Eligibility Assessments Workloads Report, and the ETA 9129, Reemployment and Eligibility Assessments Outcomes Report... Training Administration is soliciting comments on extending the collection of the ETA 9128, Reemployment...

Continuous monitoring of evapotranspiration (ET) overview of LSA-SAF evapotranspiration products

NASA Astrophysics Data System (ADS)

Arboleda, A.; Ghilain, N.; Gellens-Meulenberghs, F.

2017-10-01

Evapotranspiration (ET) is the flux of water between the surface (vegetation, soil and water bodies) and the atmosphere. Monitoring this water loss may be of crucial importance for applications in hydrology, agriculture, water use efficiency studies and drought monitoring. We introduce one of the few satellite-based operational evapotranspiration products, generated continuously and in near real-time over Europe, Africa and part of South America. The ET products (30 minutes and daily) are generated at the EUMETSAT's Satellite Application Facility on Land Surface Analysis (LSA-SAF) operations centre (http://landsaf.ipma.pt). Following our commitments to our user's community, we are continuously looking for new ways to improve the product. To accomplish this, the feedback from users and potential users of the products is of great interest. In this contribution we present the ET products characteristics and recent improvements gained thanks to the inclusion in our ET algorithm of new variables derived from Earth observation by MSG SEVIRI. We show examples of the ET products and we highlight their potential in droughts detection and monitoring. Some examples of possible applications are presented to invite users and researchers to explore the possibilities offered by LSA-SAF evapotranspiration products.

Parameter sensitivity analysis and optimization for a satellite-based evapotranspiration model across multiple sites using Moderate Resolution Imaging Spectroradiometer and flux data

NASA Astrophysics Data System (ADS)

Zhang, Kun; Ma, Jinzhu; Zhu, Gaofeng; Ma, Ting; Han, Tuo; Feng, Li Li

2017-01-01

Global and regional estimates of daily evapotranspiration are essential to our understanding of the hydrologic cycle and climate change. In this study, we selected the radiation-based Priestly-Taylor Jet Propulsion Laboratory (PT-JPL) model and assessed it at a daily time scale by using 44 flux towers. These towers distributed in a wide range of ecological systems: croplands, deciduous broadleaf forest, evergreen broadleaf forest, evergreen needleleaf forest, grasslands, mixed forests, savannas, and shrublands. A regional land surface evapotranspiration model with a relatively simple structure, the PT-JPL model largely uses ecophysiologically-based formulation and parameters to relate potential evapotranspiration to actual evapotranspiration. The results using the original model indicate that the model always overestimates evapotranspiration in arid regions. This likely results from the misrepresentation of water limitation and energy partition in the model. By analyzing physiological processes and determining the sensitive parameters, we identified a series of parameter sets that can increase model performance. The model with optimized parameters showed better performance (R2 = 0.2-0.87; Nash-Sutcliffe efficiency (NSE) = 0.1-0.87) at each site than the original model (R2 = 0.19-0.87; NSE = -12.14-0.85). The results of the optimization indicated that the parameter β (water control of soil evaporation) was much lower in arid regions than in relatively humid regions. Furthermore, the optimized value of parameter m1 (plant control of canopy transpiration) was mostly between 1 to 1.3, slightly lower than the original value. Also, the optimized parameter Topt correlated well to the actual environmental temperature at each site. We suggest that using optimized parameters with the PT-JPL model could provide an efficient way to improve the model performance.

77 FR 70833 - Comment Request for Information Collection on the ETA 9048, Worker Profiling and Reemployment...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-27

... Collection on the ETA 9048, Worker Profiling and Reemployment Services Activity, and the ETA 9049, Worker... Administration (ETA), Labor. ACTION: Notice. SUMMARY: The Department of Labor (Department), as part of its... impact of collection requirements on respondents can be properly assessed. Currently, ETA is soliciting...

Imaging Shock Fronts in the Outer Ejecta of Eta Carinae

NASA Astrophysics Data System (ADS)

Smith, Nathan

2017-08-01

Although Eta Car has been imaged many times with HST to monitor the central star and the bright Homunculus Nebula, we propose the first WFC3 imaging of Eta Car to study the more extended Outer Ejecta from previous eruptions. WFC3 has two key filters that have not been used before to image Eta Car, which will provide critical physical information about its eruptive history: (1) F280N with WFC3/UVIS will produce the first Mg II 2800 image of Eta Car, the sharpest image of its complex Outer Ejecta, and will unambiguously trace shock fronts, and (2) F126N with WFC3/IR will sample [Fe II] 12567 arising in the densest post-shock gas. Eta Car is surrounded by a bright, soft X-ray shell seen in Chandra images, which arises from the fastest 1840s ejecta overtaking slower older material. Our recent proper motion measurements show that the outer knots were ejected in two outbursts several hundred years before the 1840s eruption, and spectroscopy of light echoes has recently revealed extremely fast ejecta during the 1840s that indicate an explosive event. Were those previous eruptions explosive as well? If so, were they as energetic, did they also have such fast ejecta, and did they have the same geometry? The structure and excitation of the Outer Ejecta hold unique clues for reconstructing Eta Car's violent mass loss history. The locations of shock fronts in circumstellar material provide critical information, because they identify past discontinuities in the mass loss. This is one of the only ways to investigate the long term (i.e. centuries) evolution and duty cycle of eruptive mass loss in the most massive stars.

Utilisation of an eta(3)-allyl hydride complex, formed by UV irradiation, as a controlled source of 16-electron (eta(5)-C(5)Me(5))Rh(CH(2)[double bond, length as m-dash]CHMe).

PubMed

Sexton, Catherine J; López-Serrano, Joaquín; Lledós, Agustí; Duckett, Simon B

2008-10-21

Low temperature UV irradiation of solutions of (eta(5)-C(5)Me(5))Rh(CH(2)[double bond, length as m-dash]CHMe)(2) yields (eta(5)-C(5)Me(5))Rh(eta(3)-CH(2)CHCH(2))(H), which provides controlled access to the 16-electron fragment (eta(5)-C(5)Me(5))Rh(CH(2)[double bond, length as m-dash]CHMe).

Constraints on Decreases in Eta Carinae's Mass-loss from 3D Hydrodynamic Simulations of Its Binary Colliding Winds

NASA Technical Reports Server (NTRS)

Madura, T. I.; Gull, T. R.; Okazaki, A. T.; Russell, C. M. P.; Owocki, S. P.; Groh, J. H.; Corcoran, M. F.; Hamaguchi, K.; Teodoro, M.

2013-01-01

Recent work suggests that the mass-loss rate of the primary star Eta-A in the massive colliding wind binary Eta Carinae dropped by a factor of 2-3 between 1999 and 2010. We present result from large- (+/- 1545 au) and small- (+/- 155 au) domain, 3D smoothed particle hydrodynamics (SPH) simulations of Eta Car's colliding winds for three Eta-A mass-loss rates ( (dot-M(sub Eta-A) = 2.4, 4.8 and 8.5 × 10(exp -4) M(solar)/ yr), investigating the effects on the dynamics of the binary wind-wind collision (WWC). These simulations include orbital motion, optically thin radiative cooling and radiative forces. We find that dot-M Eta-A greatly affects the time-dependent hydrodynamics at all spatial scales investigated. The simulations also show that the post-shock wind of the companion star Eta-B switches from the adiabatic to the radiative-cooling regime during periastron passage (Phi approx.= 0.985-1.02). This switchover starts later and ends earlier the lower the value of dot-M Eta-A and is caused by the encroachment of the wind of Eta-A into the acceleration zone of Eta-B's wind, plus radiative inhibition of Eta-B's wind by Eta-A. The SPH simulations together with 1D radiative transfer models of Eta-A's spectra reveal that a factor of 2 or more drop in dot-M EtaA should lead to substantial changes in numerous multiwavelength observables. Recent observations are not fully consistent with the model predictions, indicating that any drop in dot- M Eta-A was likely by a factor of approx. < 2 and occurred after 2004. We speculate that most of the recent observed changes in Eta Car are due to a small increase in the WWC opening angle that produces significant effects because our line of sight to the system lies close to the dense walls of the WWC zone. A modest decrease in dot-M Eta-A may be responsible, but changes in the wind/stellar parameter of Eta-B, while less likely, cannot yet be fully ruled out. We suggest observations during Eta-Car's next periastron in 2014 to further

Coupling Evapotranspiration and Watershed Storage to Assess the Impact of Forest Disturbance on Low Flows

NASA Astrophysics Data System (ADS)

Brena Naranjo, J.; Stahl, K.; Weiler, M.

2009-05-01

Low flows are important for water-supply planning and design, and maintenance of quantity and quality of water for irrigation, recreation, and fish and wildlife conservation. There have been concerns recently that climate warming and land cover changes due to an unprecedented pine beetle epidemic in British Columbia, Canada, may cause a deterioration of water quantity during low flow periods and at certain times may become a hazard to ecosystem and to water management schemes. A study to characterize the sensitivity of the low flow regimes was performed for several mainly forested catchments located within the Fraser River basin. Here, summer low flows are maintained through the release of water from groundwater and riparian storage, lakes and wetlands, but are reduced by high evapotranspiration rates in the catchments. Since evapotranspiration in British Columbia accounts around 40% of the precipitation, the first part of this work was focused on the assessment of the relationship between the potential evapotranspiration (PET) and the actual evapotranspiration (AET) for undisturbed and disturbed landscapes which is expected to influence the hydrological behavior during the low-flow season. Through its influence on evapotranspiration, forest age appears to play an important role in the water balance. The second part of the study implemented a forest age dependent calculation of AET into a parsimonious water balance model, which was applied to simulate the sensitivity of the flow regimes of 15 non regulated watersheds to changes after the beginning of the pine beetle epidemic at a large scale. The model input was derived from disaggregated gridded 30-year climate normals. Since the geologic and topographic properties are first order controls on water storage and release of the examined catchments a framework for regionalization of these properties into ungauged catchments was developed. Furthermore, the interaction between forest disturbance and evapotranspiration

Eta-mesic nuclei: Past, present, future

DOE PAGES

Haider, Q.; Liu, Lon -Chang

2015-09-23

Eta-mesic nucleus or the quasibound nuclear state of an eta (η) meson in a nucleus is caused by strong interaction force alone. This new type of nuclear species, which extends the landscape of nuclear physics, has been extensively studied since its prediction in 1986. We review and analyze in great detail the models of the fundamental η–nucleon interaction leading to the formation of an η–mesic nucleus, the methods used in calculating the properties of a bound η, and the approaches employed in the interpretation of the pertinent experimental data. In view of the successful observation of the η–mesic nucleus 25Mgmore » η and other promising experimental results, future direction in searching for more η–mesic nuclei is suggested.« less

Eta Meson Production in Proton-Proton and Nuclear Collisions

NASA Technical Reports Server (NTRS)

Norbury, John W.; Dick, Frank

2008-01-01

Total cross sections for eta meson production in proton - proton collisions are calculated. The eta meson is mainly produced via decay of the excited nucleon resonance at 1535 MeV. A scalar quantum field theory is used to calculate cross sections, which also include resonance decay. Comparison between theory and experiment is problematic near threshold when resonance decay is not included. When the decay is included, the comparison between theory and experiment is much better.

Prediction of the Reference Evapotranspiration Using a Chaotic Approach

PubMed Central

Wang, Wei-guang; Zou, Shan; Luo, Zhao-hui; Zhang, Wei; Kong, Jun

2014-01-01

Evapotranspiration is one of the most important hydrological variables in the context of water resources management. An attempt was made to understand and predict the dynamics of reference evapotranspiration from a nonlinear dynamical perspective in this study. The reference evapotranspiration data was calculated using the FAO Penman-Monteith equation with the observed daily meteorological data for the period 1966–2005 at four meteorological stations (i.e., Baotou, Zhangbei, Kaifeng, and Shaoguan) representing a wide range of climatic conditions of China. The correlation dimension method was employed to investigate the chaotic behavior of the reference evapotranspiration series. The existence of chaos in the reference evapotranspiration series at the four different locations was proved by the finite and low correlation dimension. A local approximation approach was employed to forecast the daily reference evapotranspiration series. Low root mean square error (RSME) and mean absolute error (MAE) (for all locations lower than 0.31 and 0.24, resp.), high correlation coefficient (CC), and modified coefficient of efficiency (for all locations larger than 0.97 and 0.8, resp.) indicate that the predicted reference evapotranspiration agrees well with the observed one. The encouraging results indicate the suitableness of chaotic approach for understanding and predicting the dynamics of the reference evapotranspiration. PMID:25133221

Prediction of the reference evapotranspiration using a chaotic approach.

PubMed

Wang, Wei-guang; Zou, Shan; Luo, Zhao-hui; Zhang, Wei; Chen, Dan; Kong, Jun

2014-01-01

Evapotranspiration is one of the most important hydrological variables in the context of water resources management. An attempt was made to understand and predict the dynamics of reference evapotranspiration from a nonlinear dynamical perspective in this study. The reference evapotranspiration data was calculated using the FAO Penman-Monteith equation with the observed daily meteorological data for the period 1966-2005 at four meteorological stations (i.e., Baotou, Zhangbei, Kaifeng, and Shaoguan) representing a wide range of climatic conditions of China. The correlation dimension method was employed to investigate the chaotic behavior of the reference evapotranspiration series. The existence of chaos in the reference evapotranspiration series at the four different locations was proved by the finite and low correlation dimension. A local approximation approach was employed to forecast the daily reference evapotranspiration series. Low root mean square error (RSME) and mean absolute error (MAE) (for all locations lower than 0.31 and 0.24, resp.), high correlation coefficient (CC), and modified coefficient of efficiency (for all locations larger than 0.97 and 0.8, resp.) indicate that the predicted reference evapotranspiration agrees well with the observed one. The encouraging results indicate the suitableness of chaotic approach for understanding and predicting the dynamics of the reference evapotranspiration.

Comparing SEBAL and METRIC: Evapotranspiration Models Applied to Paramount Farms Almond Orchards

NASA Astrophysics Data System (ADS)

Furey, B. J.; Kefauver, S. C.

2011-12-01

Two evapotranspiration models were applied to almond and pistachio orchards in California. The SEBAL model, developed by W.G.M. Bastiaanssen, was programmed in MatLab for direct comparison to the METRIC model, developed by R.G. Allen and the IDWR. Remote sensing data from the NASA SARP 2011 Airborne Research Program was used in the application of these models. An evaluation of the models showed that they both followed the same pattern in evapotranspiration (ET) rates for different types of ground cover. The models exhibited a slightly different range of values and appeared to be related (non-linearly). The models both underestimated the actual ET at the CIMIS weather station. However, SEBAL overestimated the ET of the almond orchards by 0.16 mm/hr when applying its crop coefficient to the reference ET. This is compared to METRIC, which underestimated the ET of the almond orchards by only 0.10 mm/hr. Other types of ground cover were similarly compared. Temporal variability in ET rates between the morning and afternoon were also observed.

76 FR 12760 - Comment Request for Information Collection for Report ETA 902, Disaster Unemployment Assistance...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-08

... Collection for Report ETA 902, Disaster Unemployment Assistance Activities (OMB Control No. 1205- 0051... soliciting comments concerning the proposed extension of the ETA 902, Disaster Unemployment [email protected] . SUPPLEMENTARY INFORMATION: I. Background The ETA 902 Report, Disaster Unemployment...

Quantifying energy and water fluxes in dry dune ecosystems of the Netherlands

NASA Astrophysics Data System (ADS)

Voortman, B. R.; Bartholomeus, R. P.; van der Zee, S. E. A. T. M.; Bierkens, M. F. P.; Witte, J. P. M.

2015-09-01

Coastal and inland dunes provide various ecosystem services that are related to groundwater, such as drinking water production and biodiversity. To manage groundwater in a sustainable manner, knowledge of actual evapotranspiration (ETa) for the various land covers in dunes is essential. Aiming at improving the parameterization of dune vegetation in hydrometeorological models, this study explores the magnitude of energy and water fluxes in an inland dune ecosystem in the Netherlands. Hydrometeorological measurements were used to parameterize the Penman-Monteith evapotranspiration model for four different surfaces: bare sand, moss, grass and heather. We found that the net longwave radiation (Rnl) was the largest energy flux for most surfaces during daytime. However, modeling this flux by a calibrated FAO-56 Rnl model for each surface and for hourly time steps was unsuccessful. Our Rnl model, with a novel submodel using solar elevation angle and air temperature to describe the diurnal pattern in radiative surface temperature, improved Rnl simulations considerably. Model simulations of evaporation from moss surfaces showed that the modulating effect of mosses on the water balance is species-dependent. We demonstrate that dense moss carpets (Campylopus introflexus) evaporate more (5 %, +14 mm) than bare sand (total of 258 mm in 2013), while more open-structured mosses (Hypnum cupressiforme) evaporate less (-30 %, -76 mm) than bare sand. Additionally, we found that a drought event in the summer of 2013 showed a pronounced delayed signal on lysimeter measurements of ETa for the grass and heather surfaces, respectively. Due to the desiccation of leaves after the drought event, and their feedback on the surface resistance, the potential evapotranspiration in the year 2013 dropped by 9 % (-37 mm) and 10 % (-61 mm) for the grass and heather surfaces, respectively, which subsequently led to lowered ETa of 8 % (-29 mm) and 7 % (-29 mm). These feedbacks are of importance for

Quantifying energy and water fluxes in dry dune ecosystems of the Netherlands

NASA Astrophysics Data System (ADS)

Voortman, B. R.; Bartholomeus, R. P.; van der Zee, S. E. A. T. M.; Bierkens, M. F. P.; Witte, J. P. M.

2015-04-01

Coastal and inland dunes provide various ecosystem services that are related to groundwater, such as drinking water production and biodiversity. To manage groundwater in a sustainable manner, knowledge of actual evapotranspiration (ETa) for the various land covers in dunes is essential. Aiming at improving the parameterization of dune vegetation in hydro-meteorological models, this study explores the magnitude of energy and water fluxes in an inland dune ecosystem in the Netherlands. Hydro-meteorological measurements were used to parameterize the Penman-Monteith evapotranspiration model for four different surfaces: bare sand, moss, grass and heather. We found that the net longwave radiation (Rnl) was the largest energy flux for most surfaces during daytime. However, modelling this flux by a calibrated FAO-56 Rnl model for each surface and for hourly time steps was unsuccessful. Our Rnl model, with a novel sub-model using solar elevation angle and air temperature to describe the diurnal pattern in radiative surface temperature, improved Rnl simulations considerably. Model simulations of evaporation from moss surfaces showed that the modulating effect of mosses on the water balance is species dependent. We demonstrate that dense moss carpets (Campylopus introflexus) evaporate more (5%, +14 mm) than bare sand (total of 258 mm in 2013), while more open structured mosses (Hypnum cupressiforme) evaporate less (-30%, -76 mm) than bare sand. Additionally, we found that a drought event in the summer of 2013 showed a pronounced delayed signal on lysimeter measurements of ETa for the grass and heather surfaces respectively. Due to the desiccation of leaves after the drought event, and their feedback on the parameters of the Penman-Monteith equation, the potential evapotranspiration in the year 2013 dropped with 9% (-37mm) and 10% (-61 mm) for the grass and heather surfaces respectively, which subsequently led to lowered ETa of 8% (-29 mm) and 7% (-29 mm). These feedbacks are

77 FR 69503 - Comment Request for Information Collection on the ETA 218, Benefit Rights and Experience Report...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-19

... Collection on the ETA 218, Benefit Rights and Experience Report, Extension Without Revisions AGENCY: Employment and Training Administration (ETA), Labor. ACTION: Notice. SUMMARY: The Department of Labor.... Currently, ETA is soliciting comments concerning the collection of data on the ETA 218, Benefit Rights and...

Environmental controls on seasonal ecosystem evapotranspiration/potential evapotranspiration ratio as determined by the global eddy flux measurements

Treesearch

Chunwei Liu; Ge Sun; Steve McNulty; Asko Noormets; Yuan Fang

2017-01-01

The evapotranspiration / potential evapotranspiration (AET / PET) ratio is traditionally termed as the crop coefficient (Kc) and has been generally used as ecosystem evaporative stress index. In the current hydrology literature, Kc has been widely used as a parameter to estimate crop water demand by water managers but has...

Cautionary Note on Reporting Eta-Squared Values from Multifactor ANOVA Designs

ERIC Educational Resources Information Center

Pierce, Charles A.; Block, Richard A.; Aguinis, Herman

2004-01-01

The authors provide a cautionary note on reporting accurate eta-squared values from multifactor analysis of variance (ANOVA) designs. They reinforce the distinction between classical and partial eta-squared as measures of strength of association. They provide examples from articles published in premier psychology journals in which the authors…

78 FR 30336 - Comment Request for Information Collection: ETA-5130 Benefit Appeals Report; Extension Without...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-22

... Collection: ETA-5130 Benefit Appeals Report; Extension Without Change AGENCY: Employment and Training... ETA-5130, Benefit Appeals Report, contains information on the number of unemployment insurance appeals... proposed extension collection of the ETA-5130 Benefit Appeals Report, which expires January 31, 2014...

Is the Ejecta of ETA Carinae Overabundant or Overexcited

NASA Technical Reports Server (NTRS)

Gull, Theodore; Davidson, Kris; Johansson, Sveneric; Damineli, Augusto; Ishibashi, Kaxunori; Corcoran, Michael; Hartman, Henrick; Viera, Gladys; Nielsen, Krister

2003-01-01

The ejecta of Eta Carinae, revealed by HST/STIS, are in a large range of physical conditions. As Eta Carinae undergoes a 5.52 period, changes occur in nebular emission and nebular absorption. "Warm" neutral regions, partially ionized regions, and fully ionized regions undergo significant changes. Over 2000 emission lines, most of Fe-like elements, have been indentified in the Weigelt blobs B and D. Over 500 emission lines have been indentified in the Strontium Filament. An ionized Little Homunculus is nestled within the neutral-shelled Homunculus. In line of sight, over 500 nebular absorption lines have been identified with up to twenty velocity components. STIS is following changes in many nebular emission and absorption lines as Eta Carinae approaches the minimum, predicted to be in June/July 2003, during the General Assembly. Coordinated observations with HST, CHANDRA, RXTE, FUSE, UVES/VLT, Gemini and other observatories are following this minimum.

PKC{eta} is a negative regulator of AKT inhibiting the IGF-I induced proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shahaf, Galit; Rotem-Dai, Noa; Koifman, Gabriela

2012-04-15

The PI3K-AKT pathway is frequently activated in human cancers, including breast cancer, and its activation appears to be critical for tumor maintenance. Some malignant cells are dependent on activated AKT for their survival; tumors exhibiting elevated AKT activity show sensitivity to its inhibition, providing an Achilles heel for their treatment. Here we show that the PKC{eta} isoform is a negative regulator of the AKT signaling pathway. The IGF-I induced phosphorylation on Ser473 of AKT was inhibited by the PKC{eta}-induced expression in MCF-7 breast adenocarcinoma cancer cells. This was further confirmed in shRNA PKC{eta}-knocked-down MCF-7 cells, demonstrating elevated phosphorylation on AKTmore » Ser473. While PKC{eta} exhibited negative regulation on AKT phosphorylation it did not alter the IGF-I induced ERK phosphorylation. However, it enhanced ERK phosphorylation when stimulated by PDGF. Moreover, its effects on IGF-I/AKT and PDGF/ERK pathways were in correlation with cell proliferation. We further show that both PKC{eta} and IGF-I confer protection against UV-induced apoptosis and cell death having additive effects. Although the protective effect of IGF-I involved activation of AKT, it was not affected by PKC{eta} expression, suggesting that PKC{eta} acts through a different route to increase cell survival. Hence, our studies show that PKC{eta} provides negative control on AKT pathway leading to reduced cell proliferation, and further suggest that its presence/absence in breast cancer cells will affect cell death, which could be of therapeutic value.« less

The X-ray Lightcurve of Eta Carinae, 1996-2014

NASA Astrophysics Data System (ADS)

Corcoran, Michael F.; Hamaguchi, Kenji; Liburd, Jamar; Gull, Theodore R.; Madura, Thomas; Teodoro, Mairan; Moffat, Anthony F. J.; Richardson, Noel; Russell, Christopher Michael Post; Pollock, A.; Owocki, Stanley P.

2015-01-01

Eta Carinae is the nearest example of a supermassive, superluminous, unstable star. Mass loss from the system is important in shaping its circumstellar medium and in determining the ultimate fate of the star. Eta Car loses mass via a dense, slow stellar wind and possesses one of the largest mass loss rates known. It is prone to episodes of extreme mass ejection via eruptions from some as-yet unspecified cause; the best examples of this are the large-scale eruptions which occurred in the mid-19th century, and then again about 50 years later. Eta Car is a colliding wind binary in which strong variations in X-ray emission and in other wavebands are driven by the violent collision of the wind of Eta Car and the fast, less dense wind of an otherwise hidden companion star. X-ray variations are the simplest diagnostic we have to study the wind-wind collision and allow us to measure the state of the stellar mass loss from both stars. We present the X-ray lightcurve over the last 20 years from monitoring observations with the Rossi X-ray Timing Explorer and the X-ray Telescope on the Swift satellite, and compare and contrast the behavior of the X-ray emission from the system over that timespan, including surprising variations during the 2014 X-ray minimum.

Recruitment of DNA polymerase eta by FANCD2 in the early response to DNA damage.

PubMed

Fu, Dechen; Dudimah, Fred Duafalia; Zhang, Jun; Pickering, Anna; Paneerselvam, Jayabal; Palrasu, Manikandan; Wang, Hong; Fei, Peiwen

2013-03-01

How Fanconi anemia (FA) protein D2 (FANCD2) performs DNA damage repair remains largely elusive. We report here that translesion synthesis DNA polymerase (pol) eta is a novel mediator of FANCD2 function. We found that wild type (wt) FANCD2, not K561R (mt) FANCD2, can interact with pol eta. Upon DNA damage, the interaction of pol eta with FANCD2 occurs earlier than that with PCNA, which is in concert with our finding that FANCD2 monoubiquitination peaks at an earlier time point than that of PCNA monoubiquitination. FANCD2-null FA patient cells (PD20) carrying histone H2B-fused pol eta and wtFANCD2, respectively, show a similar tendency of low Mitomycin C (MMC) sensitivity, while cells transfected with empty vector control or pol eta alone demonstrate a similar high level of MMC sensitivity. It therefore appears that FANCD2 monoubiquitination plays a similar anchor role as histone to bind DNA in regulating pol eta. Collectively, our study indicates that, in the early phase of DNA damage response, FANCD2 plays crucial roles in recruiting pol eta to the sites of DNA damage for repair.

Recruitment of DNA polymerase eta by FANCD2 in the early response to DNA damage

PubMed Central

Fu, Dechen; Dudimah, Fred Duafalia; Zhang, Jun; Pickering, Anna; Paneerselvam, Jayabal; Palrasu, Manikandan; Wang, Hong; Fei, Peiwen

2013-01-01

How Fanconi anemia (FA) protein D2 (FANCD2) performs DNA damage repair remains largely elusive. We report here that translesion synthesis DNA polymerase (pol) eta is a novel mediator of FANCD2 function. We found that wild type (wt) FANCD2, not K561R (mt) FANCD2, can interact with pol eta. Upon DNA damage, the interaction of pol eta with FANCD2 occurs earlier than that with PCNA, which is in concert with our finding that FANCD2 monoubiquitination peaks at an earlier time point than that of PCNA monoubiquitination. FANCD2-null FA patient cells (PD20) carrying histone H2B-fused pol eta and wtFANCD2, respectively, show a similar tendency of low Mitomycin C (MMC) sensitivity, while cells transfected with empty vector control or pol eta alone demonstrate a similar high level of MMC sensitivity. It therefore appears that FANCD2 monoubiquitination plays a similar anchor role as histone to bind DNA in regulating pol eta. Collectively, our study indicates that, in the early phase of DNA damage response, FANCD2 plays crucial roles in recruiting pol eta to the sites of DNA damage for repair. PMID:23388460

Measurements of B --> {pi,eta,eta;{'}}lnu_{l} branching fractions and determination of |V_{ub}| with semileptonically tagged B mesons.

PubMed

Aubert, B; Bona, M; Karyotakis, Y; Lees, J P; Poireau, V; Prencipe, E; Prudent, X; Tisserand, V; Garra Tico, J; Grauges, E; Lopez, L; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Cahn, R N; Jacobsen, R G; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Osipenkov, I L; Ronan, M T; Tackmann, K; Tanabe, T; Hawkes, C M; Soni, N; Watson, A T; Koch, H; Schroeder, T; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Barrett, M; Khan, A; Teodorescu, L; Blinov, V E; Bukin, A D; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Gary, J W; Liu, F; Long, O; Shen, B C; Vitug, G M; Yasin, Z; Zhang, L; Sharma, V; Campagnari, C; Hong, T M; Kovalskyi, D; Mazur, M A; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Wang, L; Wilson, M G; Winstrom, L O; Cheng, C H; Doll, D A; Echenard, B; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Ford, W T; Gaz, A; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Smith, J G; Ulmer, K A; Wagner, S R; Ayad, R; Soffer, A; Toki, W H; Wilson, R J; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Karbach, M; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Kobel, M J; Mader, W F; Nogowski, R; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Playfer, S; Watson, J E; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Santoro, V; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Klose, V; Lacker, H M; De Nardo, G; Lista, L; Monorchio, D; Onorato, G; Sciacca, C; Bard, D J; Dauncey, P D; Nash, J A; Panduro Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Cochran, J; Crawley, H B; Dong, L; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Béquilleux, J; D'Orazio, A; Davier, M; Firmino da Costa, J; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Burke, J P; Chavez, C A; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Sacco, R; Sigamani, M; Cowan, G; Flaecher, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Alwyn, K E; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Dallapiccola, C; Hertzbach, S S; Li, X; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Knoepfel, K J; Losecco, J M; Wang, W F; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Sekula, S J; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Castelli, G; Gagliardi, N; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Del Amo Sanchez, P; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; Hamon, O; Leruste, Ph; Ocariz, J; Perez, A; Prendki, J; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Biesiada, J; Lopes Pegna, D; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Anulli, F; Baracchini, E; Cavoto, G; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Franek, B; Olaiya, E O; Roethel, W; Wilson, F F; Emery, S; Escalier, M; Esteve, L; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; White, R M; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Benitez, J F; Cenci, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Gabareen, A M; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Lindquist, B; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; Neal, H; Nelson, S; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; Wagner, A P; Weaver, M; West, C A; Wisniewski, W J; Wittgen, M; Wright, D H; Wulsin, H W; Yarritu, A K; Yi, K; Young, C C; Ziegler, V; Burchat, P R; Edwards, A J; Majewski, S A; Miyashita, T S; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Pan, B; Saeed, M A; Zain, S B; Spanier, S M; Wogsland, B J; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Drummond, B W; Izen, J M; Lou, X C; Bianchi, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Choi, H H F; Hamano, K; Kowalewski, R; Lewczuk, M J; Nugent, I M; Roney, J M; Sobie, R J; Gershon, T J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Dasu, S; Flood, K T; Pan, Y; Pierini, M; Prepost, R; Vuosalo, C O; Wu, S L

2008-08-22

We report measurements of branching fractions for the decays B-->Plnu_{l}, where P are the pseudoscalar charmless mesons pi;{-}, pi;{0}, eta and eta;{'}, based on 348 fb;{-1} of data collected with the BABAR detector, using B0 and B+ mesons found in the recoil of a second B meson decaying as B-->D;{(*)}lnu_{l}. Assuming isospin symmetry, we combine pionic branching fractions to obtain B(B;{0}-->pi;{-}l;{+}nu_{l})=(1.54+/-0.17_{(stat)}+/-0.09_{(syst)})x10;{-4}; we find 3.2sigma evidence of the decay B;{+}-->etal;{+}nu_{l} and measure its branching fraction to be (0.64+/-0.20_{(stat)}+/-0.03_{(syst)})x10;{-4}, and determine B(B;{+}-->eta;{'}l;{+}nu_{l})<0.47x10;{-4} to 90% confidence level. Using partial branching fractions for the pionic decays in ranges of the momentum transfer and a variety of form factor calculation, we obtain values of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V_{ub}| in ranging from 3.6x10;{-3} to 4.1x10;{-3}.

Know your community: evapotranspiration measurement and modeling

USDA-ARS?s Scientific Manuscript database

This publication discusses the Evapotranspiration Measurement and Modeling Community in the Agronomy Society of America. The importance of Evapotranspiration (ET) for agricultural studies is discussed along with research tools and methodologies for measuring and modeling ET. We discuss the communi...

Excited Ejecta in Light of Sight from Eta Car

NASA Technical Reports Server (NTRS)

Vieira, G.; Gull, T. R.; Danks, A.

2003-01-01

In the NUV spectrum of Eta Car, we have resolved many narrow absorption lines of neutral and singly-ionized elements with the Space Telescope Imaging Spectrograph. We report for the first time the detection of interstellar vanadium in absorption, and many highly-excited absorption lines of Fe, Cr, Ti, Ni, Co, Mn, and Mg. These elements, normally tied up in dust grains in the ISM, are located within wall of the Homunculus within 20,000 A.U. of Eta Car. Stellar radiation and stellar wind are interacting with the wall. Dust is likely being modified and/or destroyed. Previous Homunculus studies have demonstrated that nitrogen is overabundant and that carbon and oxygen emission lines are weak, or non-existent. Are the large column densities of these heavy elements due to abundance effects, excitation mechanisms, or modified grains? We may gain insight as Eta Car goes through its spectroscopic minimum in the summer of 2003.

Spatially distributed evapotranspiration and recharge estimation for sand regions of Hungary in the context of climate change

NASA Astrophysics Data System (ADS)

Csáki, Péter; Kalicz, Péter; Gribovszki, Zoltán

2016-04-01

Water balance of sand regions of Hungary was analysed using remote-sensing based evapotranspiration (ET) maps (1*1 km spatial resolution) by CREMAP model over the 2000-2008 period. The mean annual (2000-2008) net groundwater recharge (R) estimated as the difference in mean annual precipitation (P) and ET, taking advantage that for sand regions the surface runoff is commonly negligible. For the examined nine-year period (2000-2008) the ET and R were about 90 percent and 10 percent of the P. The mean annual ET and R were analysed in the context of land cover types. A Budyko-model was used in spatially-distributed mode for the climate change impact analysis. The parameters of the Budyko-model (α) was calculated for pixels without surplus water. For the extra-water affected pixels a linear model with β-parameters (actual evapotranspiration / pan-evapotranspiration) was used. These parameter maps can be used for evaluating future ET and R in spatially-distributed mode (1*1 km resolution). By using the two parameter maps (α and β) and data of regional climate models (mean annual temperature and precipitation) evapotranspiration and net groundwater recharge projections have been done for three future periods (2011-2040, 2041-2070, 2071-2100). The expected ET and R changes have been determined relative to a reference period (1981-2010). According to the projections, by the end of the 21th century, ET may increase while in case of R a heavy decrease can be detected for the sand regions of Hungary. This research has been supported by Agroclimate.2 VKSZ_12-1-2013-0034 project. Keywords: evapotranspiration, net groundwater recharge, climate change, Budyko-model

Impact of Atmospheric Albedo on Amazon Evapotranspiration

NASA Astrophysics Data System (ADS)

Lopes, A. V.; Thompson, S. E.; Dracup, J. A.

2013-12-01

The vulnerability of the Amazon region to climate and anthropogenic driven disturbances has been the subject of extensive research efforts, given its importance in the global and regional climate and ecologic systems. The evaluation of such vulnerabilities requires the proper understanding of physical mechanisms controlling water and energy balances and how the disturbances change them. Among those mechanisms, the effects of atmospheric albedo on evapotranspiration have not been fully explored yet and are explored in this study. Evapotranspiration in the Amazon is sustained at high levels across all seasons and represents a large fraction of water and energy surface budgets. In this study, statistical analysis of data from four flux towers installed at Amazon primary forest sites was employed to quantify the impact of atmospheric albedo, mostly resulted from cloudiness, on evapotranspiration and to compare it to the effect of water limitation. Firstly, the difference in eddy-flux derived evapotranspiration at the flux towers under rainy and non-rainy antecedent conditions was tested for significance. Secondly, the same statistical comparison was performed under cloudy and clear sky conditions at hourly and daily time scales, using the reduction in incoming solar radiation as an indicator of cloudiness. Finally, the sensitivity of seasonal evapotranspiration totals to atmospheric albedo resulted from rainfall patterns is evaluated. That was done by sampling daily evapotranspiration estimates from empirical probability distribution functions conditioned to rainfall occurrence and then varying the number of dry days in each season. It was found that light limitation is much more important than water limitation in the Amazon, resulting in up to 43% reduction in daily evapotranspiration. Also, this effect varies by location and by season, the largest impact being in wet season, from December do January. Moreover, seasonal evapotranspiration totals were found to be

Which hadronic decay modes are good for {eta}{sub b} searching: Double J/{psi} or something else?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jia Yu

2008-09-01

It has been controversial whether {eta}{sub b} can be discovered in Tevatron Run 2 through the decay {eta}{sub b}{yields}J/{psi}J/{psi} followed by J/{psi}{yields}{mu}{sup +}{mu}{sup -}. I clear this controversy by an explicit calculation which predicts Br[{eta}{sub b}{yields}J/{psi}J/{psi}] to be of order 10{sup -8}. It is concluded that observing {eta}{sub b} through this decay mode in Tevatron Run 2 may be rather unrealistic. The {eta}{sub b} may be observed in the forthcoming CERN LHC experiments through the 4-lepton channel, if the background events can be significantly reduced by imposing some kinematical cuts. By some rough but plausible considerations, I find that themore » analogous decay processes {eta}{sub b}{yields}VV, D*D* also have very suppressed branching ratios; nevertheless it may be worth looking for {eta}{sub b} at LHC and Super B factory through the decay modes {eta}{sub b}{yields}K{sub S}K{sup {+-}}{pi}{sup {+-}}, D*D.« less

Mapping and Modeling the Extended Winds of the Massive Interacting Binary, Eta Carinae

NASA Technical Reports Server (NTRS)

Gull, Ted

2010-01-01

The combination HST/STIS high spatial and moderate spectral resolutions have revealed the massive interacting wind structure of Eta Carinae by forbidden lines of singly and doubly ionized elements. Throughout the 5.54-year period, lines of Fe++, Ne++, Ar++, S++ and N+ reveal the interacting wind structures, near critical electron densities of 10(exp 5) to 3 x 10(exp 7)cu cm, photoionized by the hot secondary, Eta Car B, Lines of Fe+ and Ni+ trace the denser (>10(exp 7)cu cm. less-ionized (< 8 eV) primary wind of Eta Car A as it wraps around the interacting binary stars. For 5 years of the 5.54 year period, the FUV radiation from Eta Car B escapes the orbital region, ionizing the boundaries of the expanding wind structures. But for three to six months, Eta Car B plunges into the primary wind approaching to within 1 to 2 AU, leading to cutoff of FUV and X-ray fluxes. The interacting wind structure, resolved out to 0.8", drops io ionization and then rebuilds as Eta Car B emerges from the primary wind envelope. Solid Particle Hydrodynamical(SPH) models have been developed extending out to 2000 AU and adapted to include FUV radiation effects of the winds. In turn, synthetic spectroimages of selected forbidden lines have been constructed and compared to the spectroimages recorded by the HST/STIS throughout 1998.0 to 2004.3, extending across the 1998 and 2003.5 minima. By this method, we show that the orbital axis of the binary system must bc within 15 degrees of the Homunculus axis of symmetry and that periastron occurs with Eta Car B passing on the far side of Eta Car B. This result ties the current binary orbit with the bipolar ejection with intervening skirt and leads to implications that the binary system influenced the mass ejection of the l840s and the lesser ejection of the 1890s.

77 FR 48174 - Comment Request for Information Collection for the ETA 203, Characteristics of the Insured...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-13

... Collection for the ETA 203, Characteristics of the Insured Unemployed, Extension Without Revisions AGENCY: Employment and Training Administration (ETA), Labor. ACTION: Notice. SUMMARY: The Department of Labor.... Currently, ETA is soliciting comments concerning the continuation of the collection of data on...

78 FR 75948 - Comment Request for Information Collection for the ETA 586, Interstate Arrangement for Combining...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-13

... Collection for the ETA 586, Interstate Arrangement for Combining Employment and Wages; Extension Without Change AGENCY: Employment and Training Administration (ETA), Labor. ACTION: Notice. SUMMARY: The... assessed. Currently, ETA is soliciting comments concerning the proposed extension, without change, of the...

Heterogeneous terrain: a challenge to derive evapotranspiration with remote sensing and scintillometry

NASA Astrophysics Data System (ADS)

Thiem, Christina; Sun, Liya; Müller, Benjamin; Bernhardt, Matthias; Schulz, Karsten

2014-05-01

Despite the importance of evapotranspiration for Meteorology, Hydrology and Agronomy, obtaining area-averaged evapotranspiration estimates is cost as well as maintenance intensive: usually area-averaged evapotranspiration estimates are obtained by distributed sensor networks or remotely sensed with a scintillometer. A low cost alternative for evapotranspiration estimates are satellite images, as many of them are freely available. This approach has been proven to be worthwhile above homogeneous terrain, and typically evapotranspiration data obtained with scintillometry are applied for validation. We will extend this approach to heterogeneous terrain: evapotranspiration estimates from ASTER 2013 images will be compared to scintillometer derived evapotranspiration estimates. The goodness of the correlation will be presented as well as an uncertainty estimation for both the ASTER derived and the scintillometer derived evapotranspiration.

75 FR 53983 - Proposed Information Collection Request of the ETA-5130 Benefit Appeals Report; Comment Request...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-02

... of the ETA-5130 Benefit Appeals Report; Comment Request on Extension Without Change (OMB Control [email protected] . SUPPLEMENTARY INFORMATION: I. Background The ETA-5130, Benefit Appeals Report, contains... Training Administration is soliciting comments concerning the proposed extension collection of the ETA-5130...

Formation of {eta}-mesic nuclei by the ({pi},N) reaction and properties of N*(1535) in medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagahiro, Hideko; Jido, Daisuke; Hirenzaki, Satoru

2009-08-15

We calculate formation spectra of the {eta}-nucleus systems in the ({pi},N) reactions with nuclear targets, which can be performed at existing and/or forthcoming facilities, including the Japan Proton Accelerator Research Complex, to investigate the {eta}-nucleus interaction. Based on the N*(1535) dominance in the {eta}N system, the {eta}-mesic nuclei are suitable systems for the study of in-medium properties of the N*(1535) baryon resonance, such as reduction of the mass difference of N and N* in the nuclear medium, which affects the level structure of the {eta} and N*-hole modes. We find that clear information on the in-medium N*- and {eta}-nucleus interactionsmore » can be obtained through the formation spectra of the {eta}-mesic nuclei. We also discuss the experimental feasibilities by showing several spectra of the ({pi},N) reactions calculated with possible experimental settings. Coincident measurements of the N{pi} pairs from the N* decays in nuclei help us to reduce backgrounds.« less

Remote sensing of evapotranspiration using automated calibration: Development and testing in the state of Florida

NASA Astrophysics Data System (ADS)

Evans, Aaron H.

Thermal remote sensing is a powerful tool for measuring the spatial variability of evapotranspiration due to the cooling effect of vaporization. The residual method is a popular technique which calculates evapotranspiration by subtracting sensible heat from available energy. Estimating sensible heat requires aerodynamic surface temperature which is difficult to retrieve accurately. Methods such as SEBAL/METRIC correct for this problem by calibrating the relationship between sensible heat and retrieved surface temperature. Disadvantage of these calibrations are 1) user must manually identify extremely dry and wet pixels in image 2) each calibration is only applicable over limited spatial extent. Producing larger maps is operationally limited due to time required to manually calibrate multiple spatial extents over multiple days. This dissertation develops techniques which automatically detect dry and wet pixels. LANDSAT imagery is used because it resolves dry pixels. Calibrations using 1) only dry pixels and 2) including wet pixels are developed. Snapshots of retrieved evaporative fraction and actual evapotranspiration are compared to eddy covariance measurements for five study areas in Florida: 1) Big Cypress 2) Disney Wilderness 3) Everglades 4) near Gainesville, FL. 5) Kennedy Space Center. The sensitivity of evaporative fraction to temperature, available energy, roughness length and wind speed is tested. A technique for temporally interpolating evapotranspiration by fusing LANDSAT and MODIS is developed and tested. The automated algorithm is successful at detecting wet and dry pixels (if they exist). Including wet pixels in calibration and assuming constant atmospheric conductance significantly improved results for all but Big Cypress and Gainesville. Evaporative fraction is not very sensitive to instantaneous available energy but it is sensitive to temperature when wet pixels are included because temperature is required for estimating wet pixel

77 FR 2089 - Proposed Information Collection Request of the ETA 204, Experience Rating Report; Comment Request...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-13

... DEPARTMENT OF LABOR Proposed Information Collection Request of the ETA 204, Experience Rating.... Background: The data submitted annually on the ETA-204 report enables the Employment and Training... systems. Used in conjunction with other data, the ETA-204 assists in determining the effects of certain...

75 FR 3927 - Proposed Information Collection Request for the ETA 218, Benefit Rights and Experience Report...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-25

... DEPARTMENT OF LABOR Proposed Information Collection Request for the ETA 218, Benefit Rights and... programs. The data in the ETA 218, Benefit Rights and Experience Report, includes numbers of individuals... collection of the ETA 218, Benefit Rights and Experience report. Comments are requested that: Evaluate...

Effects of water salinity on the correlation scale of Root density and Evapotranspiration fluxes

NASA Astrophysics Data System (ADS)

Ajeel, Ali; Saeed, Ali; Dragonetti, Giovanna; Comegna, Alessandro; Lamaddalena, Nicola; Coppola, Antonio

2015-04-01

Spatial pattern and the correlation of different soil and plant parameters were examined in a green bean field experiment carried out at the Mediterranean Agronomic Institute of Bari, Italy. The experiment aimed to evaluate the role of local processes of salt accumulation and transport which mainly influences the evapotranspiration (and thus the root uptake) processes under different water salinity levels. The experiment consisted of three transects of 30m length and 4.2 m width, irrigated with three different salinity levels (1dSm-1, 3dSm-1, 6dSm-1). Soil measurements (electrical conductivity and soil water content) were monitored along transects in 24 sites, 1 m apart by using TDR probes and Diviner 2000. Water storage measured by TDR and Diviner sensor were coupled for calculating directly the evapotranspiration fluxes along the whole soil profile under the different salinity levels imposed during the experiment. In the same sites, crop monitoring involved measurements of Leaf Area Index (LAI), Osmotic Potential (OP), Leaf Water Potential (LWP), and Root length Density (RlD). Soil and plant properties were analyzed by classical statistics, geostatistics methods and spectral analysis. Results indicated moderate to large spatial variability across the field for soil and plant parameters under all salinity treatments. Furthermore, cross-semivariograms exhibited a strong positive spatial interdependence between electrical conductivity of soil solution ECw with ET and RlD in transect treated with 3dSm-1 as well as with LAI in transect treated with 6dSm-1 at all 24 monitoring sites. Spectral analysis enabled to identify the observation window to sample the soil salinity information responsible for a given plant response (ET, OP, RlD). It is also allowed a clear identification of the spatial scale at which the soil water salinity level and distribution and the crop response in terms of actual evapotranspiration ET, RlD and OP, are actually correlated. Additionally

Evapotranspiration from areas of native vegetation in west-central Florida

USGS Publications Warehouse

Bidlake, W.R.; Woodham, W.M.; Lopez, Miguel Angel

1996-01-01

The micrometeorological methods of energy-balance Bowen ratio and eddy correlation probably are suitable for determining evapotranspiration from unforested sites, but the aerodynamic effects of tall tree canopies need to be considered when the methods are used for forested sites. Potential evapotranspiration methods might not yield reliable estimates of evapotranspiration for all areas of native vegetation. Estimates of annual evapotranspiration ranged from 970 millimeters for a cypress swamp site to 1,060 millimeters for a pine flatwood site.

78 FR 48463 - Comment Request for Information Collection for Form ETA 9033, Attestation by Employers Using...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-08

... Collection for Form ETA 9033, Attestation by Employers Using Alien Crewmembers for Longshore Activities in U.S. Ports and Form ETA 9033-A, Attestation by Employers Using Alien Crewmembers for Longshore... comments concerning the collection of data about Form ETA 9033 Attestation by Employers Using Alien...

[Spatiotemporal changes of potential evapotranspiration in Songnen Plain of Northeast China].

PubMed

Zhang, Yong-fang; Deng, Jun-li; Guan, De-xin; Jin, Chang-jie; Wang, An-zhi; Wu, Jia-bing; Yuan, Feng-hui

2011-07-01

Based on the daily meteorological data from 72 weather stations from 1961-2003, a quantitative analysis was conducted on the spatiotemporal changes of the potential evapotranspiration in the Plain. The Penman-Monteith model was applied to calculate the potential evapotranspiration; the Mann-Kendall test, accumulative departure curve, and climatic change rate were adopted to analyze the change trend of the evapotranspiration; and the spatial analysis function of ArcGIS was used to detect the spatial distribution of the evapotranspiration. In 1961-2003, the mean annual potential evapotranspiration in the Plain was 330 - 860 mm, and presented an overall decreasing trend, with the high value appeared in southwest region, low value in surrounding areas of southwest region, and a ring-belt increasing southwestward. The climatic change rate of the annual potential evapotranspiration was -0.21 mm x a(-1). The annual potential evapotranspiration was the highest in 1982, the lowest in 1995, and increased thereafter. Seasonally, the climatic change rate of the potential evapotranspiration in spring, summer, autumn, and winter was -0.19, 0.01, -0.05, and 0.03 mm x a(-1), respectively, suggesting that the potential evapotranspiration had a weak increase in winter and summer and a slight decrease in spring and autumn.

Origin of the Central Constant Emission Component of Eta Carinae

NASA Technical Reports Server (NTRS)

Hamaguchi, Kenji; Corocoran, M. F.; Gull, T.; Ishibashi, K.; Pittard, J. M.; Hillier, D. J.; Damineli, A.; Davidson, K.; Nielsen, K. E.; Owocki, S.;

Characteristics of precipitation recycling ratio with two evapotranspiration methods in Afro-Asian arid regions

NASA Astrophysics Data System (ADS)

Li, R.; Wang, C.

2016-12-01

The increasing precipitation in different arid regions has been observed in recent decades. While, the vapor sources, which can be classified into advective vapor and local vapor from evapotranspiration, are still uncertain in arid regions. To investigate the characteristics of local vapor in arid regions, precipitation recycling ratio (PRR) with two different evapotranspiration (ET) estimations, Penman-Monteith ET and a new approach which combined Penman-Monteith ET and surface soil moisture was calculated in arid regions of Afro-Asian continent, North Africa, West Asia and China-Mongolia, during 1980-2010. The results suggested that Penman-Monteith ET, which can be treated as regional potential ET, increased and showed an enhanced ET ability in arid regions. However, the ET calculated from the new approach, which can be treated as a reliable actual ET estimation, decreased, which means the local vapor has supplied less to total rainfall in target regions. Using the new approach ET data, PRR is calculated and analyzed. PRR in target regions ranges from 0.5% to 1.0%, which is less than the PRR calculated with Penman-Monteith ET, ranging from 3.7% to 5.6%. Meanwhile PRR decreased in China-Mongolia and North Africa while in West Asia increased in recent 30 years. Considering that a wetting trend existed in China-Mongolia and North Africa, and a drying trend occurred in West Asia, it can be concluded that PRR is a negative monitoring for Afro-Asian arid regions, where the decreasing PRR means that the more advective vapor enhanced the total precipitation, while the increasing PRR trend corresponds with less advective vapor and more local evapotranspiration contributes to increasing of total rainfall. Keywords: Afro-Asian Arid region, precipitation recycling, evapotranspiration, soil moisture.

Implications of non-sustainable agricultural water policies for the water-food nexus in large-scale irrigation systems: A remote sensing approach

NASA Astrophysics Data System (ADS)

Al Zayed, Islam Sabry; Elagib, Nadir Ahmed

2017-12-01

This study proposes a novel monitoring tool based on Satellite Remote Sensing (SRS) data to examine the status of water distribution and Water Use Efficiency (WUE) under changing water policies in large-scale and complex irrigation schemes. The aim is to improve our understanding of the water-food nexus in such schemes. With a special reference to the Gezira Irrigation Scheme (GeIS) in Sudan during the period 2000-2014, the tool devised herein is well suited for cases where validation data are absent. First, it introduces an index, referred to as the Crop Water Consumption Index (CWCI), to assess the efficiency of water policies. The index is defined as the ratio of actual evapotranspiration (ETa) over agricultural areas to total ETa for the whole scheme where ETa is estimated using the Simplified Surface Energy Balance model (SSEB). Second, the tool uses integrated Normalized Difference Vegetation Index (iNDVI), as a proxy for crop productivity, and ETa to assess the WUE. Third, the tool uses SSEB ETa and NDVI in an attempt to detect wastage of water. Four key results emerged from this research as follows: 1) the WUE has not improved despite the changing agricultural and water policies, 2) the seasonal ETa can be used to detect the drier areas of GeIS, i.e. areas with poor irrigation water supply, 3) the decreasing trends of CWCI, slope of iNDVI-ETa linear regression and iNDVI are indicative of inefficient utilization of irrigation water in the scheme, and 4) it is possible to use SSEB ETa and NDVI to identify channels with spillover problems and detect wastage of rainwater that is not used as a source for irrigation. In conclusion, the innovative tool developed herein has provided important information on the efficiency of a large-scale irrigation scheme to help rationalize laborious water management processes and increase productivity.

Turbidity of a binary fluid mixture: Determining eta

NASA Technical Reports Server (NTRS)

Jacobs, Donald T.

1994-01-01

A ground based (1-g) experiment is in progress that will measure the turbidity of a density-matched, binary fluid mixture extremely close to the critical point. By covering the range of reduced temperatures t is equivalent to (T-T(sub c))/T(sub c) from 10(exp -8) to 10(exp -2), the turbidity measurements will allow the critical exponent eta to be determined. No experiment has determined a value of the critical exponent eta, yet its value is significant to theorists in critical phenomena. Interpreting the turbidity correctly is important if future NASA flight experiments use turbidity as an indirect measurement of relative temperature in shuttle experiments on critical phenomena in fluids.

Turbidity of a Binary Fluid Mixture: Determining Eta

NASA Technical Reports Server (NTRS)

Jacobs, Donald T.

1996-01-01

A ground based (1-g) experiment is in progress that will measure the turbidity of a density-matched, binary fluid mixture extremely close to its liquid-liquid critical point. By covering the range of reduced temperatures t equivalent to (T-T(sub c)) / T(sub c) from 10(exp -8) to 10(exp -2), the turbidity measurements will allow the critical exponent eta to be determined. No experiment has precisely determined a value of the critical exponent eta, yet its value is significant to theorists in critical phenomena. Relatively simple critical phenomena, as in the liquid-liquid system studied here, serve as model systems for more complex systems near a critical point.

An Updated Decision Support Interface: A Tool for Remote Monitoring of Crop Growing Conditions

NASA Astrophysics Data System (ADS)

Husak, G. J.; Budde, M. E.; Rowland, J.; Verdin, J. P.; Funk, C. C.; Landsfeld, M. F.

2014-12-01

Remote sensing of agroclimatological variables to monitor food production conditions is a critical component of the Famine Early Warning Systems Network portfolio of tools for assessing food security in the developing world. The Decision Support Interface (DSI) seeks to integrate a number of remotely sensed and modeled variables to create a single, simplified portal for analysis of crop growing conditions. The DSI has been reformulated to incorporate more variables and give the user more freedom in exploring the available data. This refinement seeks to transition the DSI from a "first glance" agroclimatic indicator to one better suited for the differentiation of drought events. The DSI performs analysis of variables over primary agricultural zones at the first sub-national administrative level. It uses the spatially averaged rainfall, normalized difference vegetation index (NDVI), water requirement satisfaction index (WRSI), and actual evapotranspiration (ETa) to identify potential hazards to food security. Presenting this information in a web-based client gives food security analysts and decision makers a lightweight portal for information on crop growing conditions in the region. The crop zones used for the aggregation contain timing information which is critical to the DSI presentation. Rainfall and ETa are accumulated from different points in the crop phenology to identify season-long deficits in rainfall or transpiration that adversely affect the crop-growing conditions. Furthermore, the NDVI and WRSI serve as their own seasonal accumulated measures of growing conditions by capturing vegetation vigor or actual evapotranspiration deficits. The DSI is currently active for major growing regions of sub-Saharan Africa, with intention of expanding to other areas over the coming years.

Water Footprint of a Super-intensive Olive Grove Under Mediterranean Climate using Ground-based Evapotranspiration Measurements and Remote Sensing

NASA Astrophysics Data System (ADS)

Nogueira, A. M.; Paço, T. A.; Silvestre, J. C.; Gonzalez, L. F.; Santos, F. L.; Pereira, L. S.

2012-04-01

measurements were used to calculate water footprint instead of the common procedure (using evapotranspiration estimates), this might have also introduced some differences. The potential of using remote sensing techniques for the assessment of water footprint of crops has been discussed in recent literature. It can provide estimates of actual evapotranspiration, of precipitation, of surface runoff and of irrigation needs when associated with modelling. In this study we further compare the water footprint estimates using in situ evapotranspiration measurements and water footprint estimates using remote sensing techniques. A comparison with the irrigation records for this particular olive orchard will be used to validate the approaches.

NUV Spectroscopic Studies of Eta Car's Weigelt D across the 2003.5 Minimum

NASA Technical Reports Server (NTRS)

Ivarsson, S.; Nielsen, K. E.; Gull, T. R.; Hillier, J. D.

2006-01-01

HST/STIS high dispersion, high spatial resolution spectra in the near UV (2424-2705A) were recorded of Weigelt D, located 0.25" from Eta Carinae, before, during and after the star's 2003.5 minimum. Most nebular emission, including Lyman-alpha pumped Fe II and [Fe III] lines show phase dependent variations with disappearance at the minimum and reappearance a few months later. Circumstellar absorptions increase at minimum, especially in the Fe II resonance lines originating not only from ground levels but also meta stable levels well above the ground levels. These ionization/excitation effects can be explained by a sudden change in UV flux reaching the blobs, likely due to a line-of-sight obscuration of the hotter companion star, Eta Car B, recently discovered by Iping et al. (poster, this meeting). The scattered starlight seen towards Weigelt D display noticeable different line profiles than the direct starlight from Eta Carinae. P-Cygni absorption profiles in Fe II stellar lines observed directly towards Eta Carinae, show terminal velocities up to -550 km/s. However, scattered starlight of Weigelt D display significant lower velocities ranging from -40 to -150 km/s.We interpret this result to be indicative that no absorbing Fe II wind structure exists between the Central source and Weigelt D. The lower velocity absorption appears to be connected to the outer Fe II wind structure of Eta Car A extending beyond Weigelt D intersecting the observer's line of sight. This result is consistent with the highly extended wind of Eta Car A.

Evapotranspiration from areas of native vegetation in west-central Florida

USGS Publications Warehouse

Bidlake, W.R.; Woodham, W.M.; Lopez, M.A.

1993-01-01

A study was made to examine the suitability of three different micrometeorological methods for estimating evapotranspiration from selected areas of native vegetation in west-central Florida and to estimate annual evapotranspiration from those areas. Evapotranspiration was estimated using the energy- balance Bowen ratio and eddy correlation methods. Potential evapotranspiration was computed using the Penman equation. The energy-balance Bowen ratio method was used to estimate diurnal evapotrans- piration at unforested sites and yielded reasonable results; however, measurements indicated that the magnitudes of air temperature and vapor-pressure gradients above the forested sites were too small to obtain reliable evapotranspiration measurements with the energy balance Bowen ratio system. Analysis of the surface energy-balance indicated that sensible and latent heat fluxes computed using standard eddy correlation computation methods did not adequately account for available energy. Eddy correlation data were combined with the equation for the surface energy balance to yield two additional estimates of evapotranspiration. Daily potential evapotranspiration and evapotranspira- tion estimated using the energy-balance Bowen ratio method were not correlated at a unforested, dry prairie site, but they were correlated at a marsh site. Estimates of annual evapotranspiration for sites within the four vegetation types, which were based on energy-balance Bowen ratio and eddy correlation measurements, were 1,010 millimeters for dry prairie sites, 990 millimeters for marsh sites, 1,060 millimeters for pine flatwood sites, and 970 millimeters for a cypress swamp site.

Multi-Wavelength Implications of the Companion Star in eta Carinae

NASA Technical Reports Server (NTRS)

Madura, Thomas I.; Gull, Theodore R.; Groh, Jose H.; Owocki, Stanley P.; Okazaki, Atsuo; Hillier, D. John; Russell, Christopher

2012-01-01

Eta-Carinae is considered to be a massive colliding wind binary system with a highly eccentric (e approximately 0.9), 5.54-yr orbit. However, the companion star continues to evade direct detection as the primary dwarfs its emission at most wavelengths. Using three-dimensional (3-D) SPH simulations of eta-Car's colliding winds and radiative transfer codes, we are able to compute synthetic observables across multiple wavebands for comparison to the observations. The models show that the presence of a companion star has a profound influence on the observed HST/STIS UV spectrum and H-alpha line profiles, as well as the ground-based photometric monitoring. Here, we focus on the Bore Hole effect, wherein the fast wind from the hot secondary star carves a cavity in the dense primary wind, allowing increased escape of radiation from the hotter/deeper layers of the primary's extended wind photosphere. The results have important implications for interpretations of eta-Car's observables at multiple wavelengths.

Religion, evolution, and mental health: attachment theory and ETAS theory.

PubMed

Flannelly, Kevin J; Galek, Kathleen

2010-09-01

This article reviews the historical origins of Attachment Theory and Evolutionary Threat Assessment Systems Theory (ETAS Theory), their evolutionary basis and their application in research on religion and mental health. Attachment Theory has been most commonly applied to religion and mental health in research on God as an attachment figure, which has shown that secure attachment to God is positively associated with psychological well-being. Its broader application to religion and mental health is comprehensively discussed by Kirkpatrick (2005). ETAS Theory explains why certain religious beliefs--including beliefs about God and life-after-death--should have an adverse association, an advantageous association, or no association at all with mental health. Moreover, it makes specific predictions to this effect, which have been confirmed, in part. The authors advocate the application of ETAS Theory in research on religion and mental health because it explains how religious and other beliefs related to the dangerousness of the world can directly affect psychiatric symptoms through their affects on specific brain structures.

The Role of Evapotranspiration on Soil Moisture Depletion in a Small Alaskan Subarctic Farm

NASA Astrophysics Data System (ADS)

Ruairuen, W.; Fochesatto, G. J.; Sparrow, E. B.; Schnabel, W.; Zhang, M.

2013-12-01

At high latitudes the period for agriculture production is very short (110 frost-free days) and strongly depends on the availability of soil water content for vegetables to grow. In this context the evapotranspiration (ET) cycle is key variable underpinning mass and energy balance modulating therefore moisture gradients and soil dryness. Evapotranspiration (ET) from field-grown crops water stress is virtually unknown in the subarctic region. Understanding ET cycles in high latitude agricultural ecosystem is essential in terms of water management and sustainability and projection of agricultural activity. To investigate the ET cycle in farming soils a field experiment was conducted in the summer of 2012 and 2013 at the University of Alaska Fairbanks Agricultural and Forestry Experiment Station combining micrometeorological and hydrological measurements. In this case experimental plots of lettuce (Lactuca sativa) plants were grown. The experiment evaluated several components of the ET cycle such as actual evapotranspiration, reference evaporation, pan evaporation as well as soil water content and temperature profiles to link them to the vegetable growing functions. We investigated the relationship of soil moisture content and crop water use across the growing season as a function of the ET cycle. Soil water depletion was compared to daily estimates of water loss by ET during dry and wet periods. We also investigated the dependence of ET on the atmospheric boundary layer flow patterns set by the synoptic large scale weather patterns.

pi-eta mixing and charge symmetry violating NN potential in matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biswas, Subhrajyoti; Roy, Pradip; Dutt-Mazumder, Abhee K.

2010-06-15

We construct density-dependent class III charge symmetry violating (CSV) potential caused by the mixing of pi-eta mesons with off-shell corrections. The density dependence enters through the nonvanishing pi-eta mixing driven by both the neutron-proton mass difference and their asymmetric density distribution. The contribution of density-dependent mixing to the CSV potential is found to be appreciably larger than that of the vacuum part.

Method for automatic determination of soybean actual evapotranspiration under open top chambers (OTC) subjected to effects of water stress and air ozone concentration.

PubMed

Rana, Gianfranco; Katerji, Nader; Mastrorilli, Marcello

2012-10-01

The present study describes an operational method, based on the Katerji et al. (Eur J Agron 33:218-230, 2010) model, for determining the daily evapotranspiration (ET) for soybean inside open top chambers (OTCs). It includes two functions, calculated day par day, making it possible to separately take into account the effects of concentrations of air ozone and plant water stress. This last function was calibrated in function of the daily values of actual water reserve in the soil. The input variables of the method are (a) the diurnal values of global radiation and temperature, usually measured routinely in a standard weather station; (b) the daily values of the AOT40 index accumulated (accumulated ozone over a threshold of 40 ppb during daylight hours, when global radiation exceeds 50 Wm(-2)) determined inside the OTC; and (c) the actual water reserve in the soil, at the beginning of the trial. The ensemble of these input variables can be automatable; thus, the proposed method could be applied in routine. The ability of the method to take into account contrasting conditions of ozone air concentration and water stress was evaluated over three successive years, for 513 days, in ten crop growth cycles, excluding the days employed to calibrate the method. Tests were carried out in several chambers for each year and take into account the intra- and inter-year variability of ET measured inside the OTCs. On the daily scale, the slope of the linear regression between the ET measured by the soil water balance and that calculated by the proposed method, under different water conditions, are 0.98 and 1.05 for the filtered and unfiltered (or enriched) OTCs with root mean square error (RMSE) equal to 0.77 and 1.07 mm, respectively. On the seasonal scale, the mean difference between measured and calculated ET is equal to +5% and +11% for the filtered and unfiltered OTCs, respectively. The ability of the proposed method to estimate the daily and seasonal ET inside the OTCs is

Satellite retrieval of actual evapotranspiration in the Tibetan Plateau: Components partitioning, multidecadal trends and dominated factors identifying

NASA Astrophysics Data System (ADS)

Wang, Weiguang; Li, Jinxing; Yu, Zhongbo; Ding, Yimin; Xing, Wanqiu; Lu, Wenjun

2018-04-01

As the only connecting term between water balance and energy budget in the earth-atmospheric system, evapotranspiration (ET) is considered the most excellent indicator for the activity for the water and energy cycle. Under the background of global change, regional ET estimates, components partitioning as well as their spatial and temporal patterns recognition are of great importance in understanding the hydrological processes and improving water management practices. This is particularly true for the Tibetan Plateau (TP), one of most sensitive and vulnerable region in response to the environment change in the earth. In this study, with flux site observation data and monthly ET data from the monthly water balance method incorporating the terrestrial water storage changes from the Gravity Recovery and Climate Experiment satellite (GRACE) production as the multiple validations, the long-term daily ET in the TP was retrieved by a modified Penman-Monteith-Leuning (PML) model with considering evapotranspiration over snow covered area during 1982-2012. The spatial and temporal changes of partitioned three components of ET, i.e., soil evaporation (Es), transpiration through the stomata of plant (Ec) and canopy interception (Ei), were investigated in the TP. Meanwhile, how the ET components contribute to ET changes and respond to the change in environmental factors in the TP was revealed and discussed. The results indicate that Es dominates ET in most areas of the TP with the mean annual ratio of 65.7%, except southeastern regions where the vegetation coverage is high. Although regional average ET and three main components all present obvious increase trends during the past decades, high spatial heterogeneity for their trends are identified in the TP. Moreover, a mixed changing pattern can be apparently found for Es in southeastern area, Ec and Ei in northwestern and southeastern area. Spatially, the ET variation are mainly attributed to change in Es, followed by Ec and Ei

Catchments' hedging strategy on evapotranspiration for climatic variability

NASA Astrophysics Data System (ADS)

Ding, W.; Zhang, C.; Li, Y.; Tang, Y.; Wang, D.; Xu, B.

2017-12-01

Hydrologic responses to climate variability and change are important for human society. Here we test the hypothesis that natural catchments utilize hedging strategies for evapotranspiration and water storage carryover with uncertain future precipitation. The hedging strategy for evapotranspiration in catchments under different levels of water availability is analytically derived from the economic perspective. It is found that there exists hedging between evapotranspiration for current and future only with a portion of water availability. Observation data sets of 160 catchments in the United States covering the period from 1983 to 2003 demonstrate the existence of hedging in catchment hydrology and validate the proposed hedging strategies. We also find that more water is allocated to carryover storage for hedging against the future evapotranspiration risk in the catchments with larger aridity indexes or with larger uncertainty in future precipitation, i.e., long-term climate and precipitation variability control the degree of hedging.

Driving Factors of Understory Evapotranspiration within a Siberian Larch Forest

NASA Astrophysics Data System (ADS)

Tobio, A.; Loranty, M. M.; Kropp, H.; Pena, H., III; Alexander, H. D.; Natali, S.; Kholodov, A. L.; Spawn, S.; Farmer, S.

2017-12-01

Amplified rates of climate change are causing alterations in vegetation productivity, hydrologic cycling, and wildfire severity and intensity in arctic ecosystems. Boreal larch forests in northeastern Siberia are a critical but understudied ecosystem that are affected by these modifications. These forests cover 2.5 million km2 with densities ranging from spare to thick. The current average canopy cover is at around 17% and is expected to increase with the observed increases in vegetation productivity and wildfire. These projected changes in forest density can alter the proportional contributions of over- and understory vegetation to whole ecosystem evapotranspiration. Low density boreal forests have much higher rates of understory evapotranspiration and can contribute as much as 80% to total ecosystem evapotranspiration, while the understory in high density forests is responsible for only around 15% of total ecosystem evapotranspiration. The objective of this research is to understand why there are changes in understory evapotranspiration with varying overstory density by looking at light levels, biomass, vegetation, and air and soil differences. To better learn about these differences in understory evapotranspiration in boreal larch forests the driving factors of evapotranspiration were measured within a burn scar with varying densities of high, medium, and low. Water fluxes were conducted using the static chamber technique under different environmental conditions. Furthermore, controlling factors of evapotranspiration such as photosynethically active radiation, vapor pressure deficit, soil moisture, moss cover, biomass, and leaf area index were measured or derived. In general, we found that low density areas have highest rates of evapotranspiration due to larger amount of biomass, and increased access to light, despite low levels of soil moisture. These results can help us understand how and why total ecosystem water exchange will change in boreal larch forests

J/psi and psi(2S) Radiative Transitions to eta_{c}.

PubMed

Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Libby, J; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; Lopez, A; Mendez, H; Ramirez, J; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Reed, J; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hunt, J M; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Ledoux, J; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J

2009-01-09

Using 2.45x10;{7} psi(2S) decays collected with the CLEO-c detector at the Cornell Electron Storage Ring we present the most precise measurements of magnetic dipole transitions in the charmonium system. We measure B(psi(2S)-->gammaeta_{c})=(4.32+/-0.16+/-0.60)x10;{-3}, B(J/psi-->gammaeta_{c})/B(psi(2S)-->gammaeta_{c})=4.59+/-0.23+/-0.64, and B(J/psi-->gammaeta_{c})=(1.98+/-0.09+/-0.30)%. We observe a distortion in the eta_{c} line shape due to the photon-energy dependence of the magnetic dipole transition rate. We find that measurements of the eta_{c} mass are sensitive to the line shape, suggesting an explanation for the discrepancy between measurements of the eta_{c} mass in radiative transitions and other production mechanisms.

High Velocity Absorption during Eta Car B's Periastron Passage

NASA Technical Reports Server (NTRS)

Nielsen, Krister E.; Groh, J. H.; Hillier, J.; Gull, Theodore R.; Owocki, S. P.; Okazaki, A. T.; Damineli, A.; Teodoro, M.; Weigelt, G.; Hartman, H.

2010-01-01

Eta Car is one of the most luminous massive stars in the Galaxy, with repeated eruptions with a 5.5 year periodicity. These events are caused by the periastron passage of a massive companion in an eccentric orbit. We report the VLT/CRIRES detection of a strong high-velocity, (<1900 km/s) , broad absorption wing in He I at 10833 A during the 2009.0 periastron passage. Previous observations during the 2003.5 event have shown evidence of such high-velocity absorption in the He I 10833 transition, allowing us to conclude that the high-velocity gas is crossing the line-of-sight toward Eta Car over a time period of approximately 2 months. Our analysis of HST/STlS archival data with observations of high velocity absorption in the ultraviolet Si IV and C IV resonance lines, confirm the presence of a high-velocity material during the spectroscopic low state. The observations provide direct detection of high-velocity material flowing from the wind-wind collision zone around the binary system, and we discuss the implications of the presence of high-velocity gas in Eta Car during periastron

20 CFR 655.1055 - Notice to the Employment and Training Administration (ETA) and the Attorney General (AG).

Code of Federal Regulations, 2010 CFR

2010-04-01

... Administration (ETA) and the Attorney General (AG). 655.1055 Section 655.1055 Employees' Benefits EMPLOYMENT AND...-Campus Work § 655.1055 Notice to the Employment and Training Administration (ETA) and the Attorney General (AG). (a) The Administrator shall notify the Attorney General and ETA of the final determination...

The Spatially-resolved Interacting Winds of Eta Carinae: Implications on the Orbit Orientation

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Nielsen, K.E.; Corcoran, M.; Hamaguchi, K.; Madura, T.; Russell, C.; Hillier, D.J.; Owocki. S.; Okazaki, A.T.

2010-01-01

Medium-dispersion long slit spectra, recorded by HST/STIS (R=8000, Theta=0.l"), resolve the extended wind-wind interaction region of the massive binary, Eta Carinae. During the high state, extending for about five years of the 5.54-year binary period, lines of [N II], [Fe III], [S III], [Ar III] and [Ne III] extend outwards to 0.4" with a velocity range of -500 to +200 km/s. By comparison, lines of [Fe II] and [Ni II] extend to 0.7" with a velocity range of -500 to +500 km/s. During the high state, driven by the lesser wind of Eta Car B and photo-ionized by the FUV of Eta Car B, the high excitation lines originate in or near the outer ballistic portions of the wind-wind interaction region. The lower excitation lines ([Fe II] and [Ni II D originate from the boundary regions of the dominating wind of Eta Car A. As the binary system has an eccentricity exceeding 0.9, the two stars approach quite close across the periastron, estimated to be within 1 to 2 AU. As a result, Eta Car B moves into the primary wind structure, cutting off the FUV supporting the ionization of the high state lines. Forbidden emission lines of the doubly-ionized species disappear, He II 4686 drops along with the collapse of the X-ray flux. This behavior is understood through the 3-D models of A. Okazaki and of E. R. Parkin and Pittard. Discussion will address the orbit orientation relative to the geometry of the Homunculus, ejected by Eta Carinae in the 1840s.

The Spatially-resolved Interacting Winds of Eta Carinae: Implications on the Orbit Orientation

NASA Astrophysics Data System (ADS)

Gull, Theodore R.; Nielsen, K. E.; Corcoran, M.; Hamaguchi, K.; Madura, T.; Russell, C.; Hillier, D. J.; Owocki, S.; Okazaki, A. T.

2010-01-01

Medium-dispersion long slit spectra, recorded by HST/STIS (R=8000, Theta=0.1"), resolve the extended wind-wind interaction region of the massive binary, Eta Carinae. During the high state, extending for about five years of the 5.54-year binary period, lines of [N II], [Fe III], [S III], [Ar III] and [Ne III] extend outwards to 0.4" with a velocity range of -500 to +200 km/s. By comparison, lines of [Fe II] and [Ni II] extend to 0.7" with a velocity range of -500 to +500 km/s. During the high state, driven by the lesser wind of Eta Car B and photo-ionized by the FUV of Eta Car B, the high excitation lines originate in or near the outer ballistic portions of the wind-wind interaction region. The lower excitation lines ([Fe II] and [Ni II]) originate from the boundary regions of the dominating wind of Eta Car A. As the binary system has an eccentricity exceeding 0.9, the two stars approach quite close across the periastron, estimated to be within 1 to 2 AU. As a result, Eta Car B moves into the primary wind structure, cutting off the FUV supporting the ionization of the high state lines. Forbidden emission lines of the doubly-ionized species disappear, He II 4686 drops along with the collapse of the X-ray flux. This behavior is understood through the 3-D models of A. Okazaki and of E. R. Parkin and Pittard. Discussion will address the orbit orientation relative to the geometry of the Homunculus, ejected by Eta Carinae in the 1840s.

Evaluation of different methods to estimate daily reference evapotranspiration in ungauged basins in Southern Brazil

NASA Astrophysics Data System (ADS)

Ribeiro Fontoura, Jessica; Allasia, Daniel; Herbstrith Froemming, Gabriel; Freitas Ferreira, Pedro; Tassi, Rutineia

2016-04-01

Evapotranspiration is a key process of hydrological cycle and a sole term that links land surface water balance and land surface energy balance. Due to the higher information requirements of the Penman-Monteith method and the existing data uncertainty, simplified empirical methods for calculating potential and actual evapotranspiration are widely used in hydrological models. This is especially important in Brazil, where the monitoring of meteorological data is precarious. In this study were compared different methods for estimating evapotranspiration for Rio Grande do Sul, the Southernmost State of Brazil, aiming to suggest alternatives to the recommended method (Penman-Monteith-FAO 56) for estimate daily reference evapotranspiration (ETo) when meteorological data is missing or not available. The input dataset included daily and hourly-observed data from conventional and automatic weather stations respectively maintained by the National Weather Institute of Brazil (INMET) from the period of 1 January 2007 to 31 January 2010. Dataset included maximum temperature (Tmax, °C), minimum temperature (Tmin, °C), mean relative humidity (%), wind speed at 2 m height (u2, m s-1), daily solar radiation (Rs, MJ m- 2) and atmospheric pressure (kPa) that were grouped at daily time-step. Was tested the Food and Agriculture Organization of the United Nations (FAO) Penman-Monteith method (PM) at its full form, against PM assuming missing several variables not normally available in Brazil in order to calculate daily reference ETo. Missing variables were estimated as suggested in FAO56 publication or from climatological means. Furthermore, PM was also compared against the following simplified empirical methods: Hargreaves-Samani, Priestley-Taylor, Mccloud, McGuiness-Bordne, Romanenko, Radiation-Temperature, Tanner-Pelton. The statistical analysis indicates that even if just Tmin and Tmax are available, it is better to use PM estimating missing variables from syntetic data than

Evapotranspiration and remote sensing

NASA Technical Reports Server (NTRS)

Schmugge, T. J.; Gurney, R.

1982-01-01

There are three things required for evapotranspiration to occur: (1) energy (580 cal/gm) for the change of phase of the water; (2) a source of the water, i.e., adequate soil moisture in the surface layer or in the root zone of the plant; and (3) a sink for the water, i.e., a moisture deficit in the air above the ground. Remote sensing can contribute information to the first two of these conditions by providing estimates of solar insolation, surface albedo, surface temperature, vegetation cover, and soil moisture content. In addition there have been attempts to estimate precipitation and shelter air temperature from remotely sensed data. The problem remains to develop methods for effectively using these sources of information to make large area estimates of evapotranspiration.

Use of eddy-covariance methods to "calibrate" simple estimators of evapotranspiration

USGS Publications Warehouse

Sumner, David M.; Geurink, Jeffrey S.; Swancar, Amy

2017-01-01

Direct measurement of actual evapotranspiration (ET) provides quantification of this large component of the hydrologic budget, but typically requires long periods of record and large instrumentation and labor costs. Simple surrogate methods of estimating ET, if “calibrated” to direct measurements of ET, provide a reliable means to quantify ET. Eddy-covariance measurements of ET were made for 12 years (2004-2015) at an unimproved bahiagrass (Paspalum notatum) pasture in Florida. These measurements were compared to annual rainfall derived from rain gage data and monthly potential ET (PET) obtained from a long-term (since 1995) U.S. Geological Survey (USGS) statewide, 2-kilometer, daily PET product. The annual proportion of ET to rainfall indicates a strong correlation (r2=0.86) to annual rainfall; the ratio increases linearly with decreasing rainfall. Monthly ET rates correlated closely (r2=0.84) to the USGS PET product. The results indicate that simple surrogate methods of estimating actual ET show positive potential in the humid Florida climate given the ready availability of historical rainfall and PET.

[Prediction of ETA oligopeptides antagonists from Glycine max based on in silico proteolysis].

PubMed

Qiao, Lian-Sheng; Jiang, Lu-di; Luo, Gang-Gang; Lu, Fang; Chen, Yan-Kun; Wang, Ling-Zhi; Li, Gong-Yu; Zhang, Yan-Ling

2017-02-01

Oligopeptides are one of the the key pharmaceutical effective constituents of traditional Chinese medicine(TCM). Systematic study on composition and efficacy of TCM oligopeptides is essential for the analysis of material basis and mechanism of TCM. In this study, the potential anti-hypertensive oligopeptides from Glycine max and their endothelin receptor A (ETA) antagonistic activity were discovered and predicted based on in silico technologies.Main protein sequences of G. max were collected and oligopeptides were obtained using in silico gastrointestinal tract proteolysis. Then, the pharmacophore of ETA antagonistic peptides was constructed and included one hydrophobic feature, one ionizable negative feature, one ring aromatic feature and five excluded volumes. Meanwhile, three-dimensional structure of ETA was developed by homology modeling methods for further docking studies. According to docking analysis and consensus score, the key amino acid of GLN165 was identified for ETA antagonistic activity. And 27 oligopeptides from G. max were predicted as the potential ETA antagonists by pharmacophore and docking studies.In silico proteolysis could be used to analyze the protein sequences from TCM. According to combination of in silico proteolysis and molecular simulation, the biological activities of oligopeptides could be predicted rapidly based on the known TCM protein sequence. It might provide the methodology basis for rapidly and efficiently implementing the mechanism analysis of TCM oligopeptides. Copyright© by the Chinese Pharmaceutical Association.

Regional ground-water evapotranspiration and ground-water budgets, Great Basin, Nevada

USGS Publications Warehouse

Nichols, William D.

2000-01-01

PART A: Ground-water evapotranspiration data from five sites in Nevada and seven sites in Owens Valley, California, were used to develop equations for estimating ground-water evapotranspiration as a function of phreatophyte plant cover or as a function of the depth to ground water. Equations are given for estimating mean daily seasonal and annual ground-water evapotranspiration. The equations that estimate ground-water evapotranspiration as a function of plant cover can be used to estimate regional-scale ground-water evapotranspiration using vegetation indices derived from satellite data for areas where the depth to ground water is poorly known. Equations that estimate ground-water evapotranspiration as a function of the depth to ground water can be used where the depth to ground water is known, but for which information on plant cover is lacking. PART B: Previous ground-water studies estimated groundwater evapotranspiration by phreatophytes and bare soil in Nevada on the basis of results of field studies published in 1912 and 1932. More recent studies of evapotranspiration by rangeland phreatophytes, using micrometeorological methods as discussed in Chapter A of this report, provide new data on which to base estimates of ground-water evapotranspiration. An approach correlating ground-water evapotranspiration with plant cover is used in conjunction with a modified soil-adjusted vegetation index derived from Landsat data to develop a method for estimating the magnitude and distribution of ground-water evapotranspiration at a regional scale. Large areas of phreatophytes near Duckwater and Lockes in Railroad Valley are believed to subsist on ground water discharged from nearby regional springs. Ground-water evapotranspiration by the Duckwater phreatophytes of about 11,500 acre-feet estimated by the method described in this report compares well with measured discharge of about 13,500 acre-feet from the springs near Duckwater. Measured discharge from springs near Lockes

Cardiac-Specific Knockout of ETA Receptor Mitigates Paraquat-Induced Cardiac Contractile Dysfunction.

PubMed

Wang, Jiaxing; Lu, Songhe; Zheng, Qijun; Hu, Nan; Yu, Wenjun; Li, Na; Liu, Min; Gao, Beilei; Zhang, Guoyong; Zhang, Yingmei; Wang, Haichang

2016-07-01

Paraquat (1,1'-dim ethyl-4-4'-bipyridinium dichloride), a highly toxic quaternary ammonium herbicide widely used in agriculture, exerts potent toxic prooxidant effects resulting in multi-organ failure including the lung and heart although the underlying mechanism remains elusive. Recent evidence suggests possible involvement of endothelin system in paraquat-induced acute lung injury. This study was designed to examine the role of endothelin receptor A (ETA) in paraquat-induced cardiac contractile and mitochondrial injury. Wild-type (WT) and cardiac-specific ETA receptor knockout mice were challenged to paraquat (45 mg/kg, i.p.) for 48 h prior to the assessment of echocardiographic, cardiomyocyte contractile and intracellular Ca(2+) properties, as well as apoptosis and mitochondrial damage. Levels of the mitochondrial proteins for biogenesis and oxidative phosphorylation including UCP2, HSP90 and PGC1α were evaluated. Our results revealed that paraquat elicited cardiac enlargement, mechanical anomalies including compromised echocardiographic parameters (elevated left ventricular end-systolic and end-diastolic diameters as well as reduced factional shortening), suppressed cardiomyocyte contractile function, intracellular Ca(2+) handling, overt apoptosis and mitochondrial damage. ETA receptor knockout itself failed to affect myocardial function, apoptosis, mitochondrial integrity and mitochondrial protein expression. However, ETA receptor knockout ablated or significantly attenuated paraquat-induced cardiac contractile and intracellular Ca(2+) defect, apoptosis and mitochondrial damage. Taken together, these findings revealed that endothelin system in particular the ETA receptor may be involved in paraquat-induced toxic myocardial contractile anomalies possibly related to apoptosis and mitochondrial damage.

A convenient synthetic route to benz[cd]azulenes: versatile ligands with the potential to bind metals in an eta5, eta6, or eta7 fashion.

PubMed

Balduzzi, Sonya; Müller-Bunz, Helge; McGlinchey, Michael J

2004-10-25

A facile method for preparing the 2H-benz[cd]azulene system, based upon an elaboration of the guaiazulene framework, is presented. Aerial oxidation to the corresponding 8-(2-propylidene)-benz[cd]azulene, and also cycloaddition reactions with tetracyanoethylene (TCNE), are described. The first X-ray crystal structure of a 2H-benz[cd]azulene, as an eta6-coordinated Cr(CO)3 complex, is reported.

Basin Scale Estimates of Evapotranspiration Using GRACE and other Observations

NASA Technical Reports Server (NTRS)

Rodell, M.; Famiglietti, J. S.; Chen, J.; Seneviratne, S. I.; Viterbo, P.; Holl, S.; Wilson, C. R.

2004-01-01

Evapotranspiration is integral to studies of the Earth system, yet it is difficult to measure on regional scales. One estimation technique is a terrestrial water budget, i.e., total precipitation minus the sum of evapotranspiration and net runoff equals the change in water storage. Gravity Recovery and Climate Experiment (GRACE) satellite gravity observations are now enabling closure of this equation by providing the terrestrial water storage change. Equations are presented here for estimating evapotranspiration using observation based information, taking into account the unique nature of GRACE observations. GRACE water storage changes are first substantiated by comparing with results from a land surface model and a combined atmospheric-terrestrial water budget approach. Evapotranspiration is then estimated for 14 time periods over the Mississippi River basin and compared with output from three modeling systems. The GRACE estimates generally lay in the middle of the models and may provide skill in evaluating modeled evapotranspiration.

Effects of spatial variability and scale on areal -average evapotranspiration

NASA Technical Reports Server (NTRS)

Famiglietti, J. S.; Wood, Eric F.

1993-01-01

This paper explores the effect of spatial variability and scale on areally-averaged evapotranspiration. A spatially-distributed water and energy balance model is employed to determine the effect of explicit patterns of model parameters and atmospheric forcing on modeled areally-averaged evapotranspiration over a range of increasing spatial scales. The analysis is performed from the local scale to the catchment scale. The study area is King's Creek catchment, an 11.7 sq km watershed located on the native tallgrass prairie of Kansas. The dominant controls on the scaling behavior of catchment-average evapotranspiration are investigated by simulation, as is the existence of a threshold scale for evapotranspiration modeling, with implications for explicit versus statistical representation of important process controls. It appears that some of our findings are fairly general, and will therefore provide a framework for understanding the scaling behavior of areally-averaged evapotranspiration at the catchment and larger scales.

Prospective Validation of ATA and ETA Sonographic Pattern Risk of Thyroid Nodules Selected for FNAC.

PubMed

Maino, Fabio; Forleo, Raffaella; Martinelli, Martina; Fralassi, Noemi; Barbato, Filomena; Pilli, Tania; Capezzone, Marco; Brilli, Lucia; Ciuoli, Cristina; Di Cairano, Giovanni; Nigi, Laura; Pacini, Furio; Castagna, Maria Grazia

2018-06-01

Recently, the American Thyroid Association (ATA) and the European Thyroid Association (ETA) have proposed that thyroid ultrasound (US) should be used to stratify the risk of malignancy in thyroid nodules and to aid decision-making about whether fine-needle aspiration cytology (FNAC) is indicated. To validate and to compare the ATA and ETA US risk stratification systems of thyroid nodules in a prospective series of thyroid nodules submitted to FNAC. We prospectively evaluated 432 thyroid nodules selected for FNAC from 340 patients. Cytology reports were based on the five categories according to the criteria of the British Thyroid Association. The proportion of Thy2 nodules decreased significantly, whereas the proportion of Thy4/Thy5 nodules significantly increased with increasing US risk class (P < 0.0001). The ability to identify benign and malignant nodules was similar between ATA and ETA systems. According to ATA and ETA US risk stratification systems, 23.7% and 56.0% nodules did not meet the criteria for FNAC, respectively. Considering only categories at lower risk of malignancy, the cumulative malignancy rate in these nodules was 1.2% for ATA and 1.7% for ETA US risk stratification systems. ETA and ATA US risk stratification systems provide effective malignancy risk stratification for thyroid nodules. In clinical practice, using this approach, we should be able to reduce the number of unnecessary FNAC without losing clinically relevant thyroid cancer.

Synthesis and characterization of lead sulphide thin films from ethanolamine (ETA) complexing agent chemical bath

NASA Astrophysics Data System (ADS)

Gashaw Hone, Fekadu; Dejene, F. B.

2018-02-01

Polycrystalline lead sulphide (PbS) thin films were grown on glass substrates by chemical bath deposition route using ethanolamine (ETA) as a complexing agent. The effects of ETA molar concentration on the structural, morphological, electrical and optical properties of lead sulphide thin films were thoroughly studied. The XRD analyses revealed that all the deposited thin films were face center cubic crystal structure and their preferred orientations were varied along the (111) and (200) planes. The XRD results further confirmed that ETA concentration had a significant effects on the strain, average crystalline size and dislocation density of the deposited thin films. The SEM studies illustrated the evolution and transformation of surface morphology as ETA molar concentration increased from 0.41 M to 1.64 M. The energy dispersive x-ray analysis was used to verify the compositional elements of the deposited thin films. Optical spectroscopy investigation established that the band gap of the PbS thin films were reduced from 0.98 eV to 0.68 eV as ETA concentration increased. The photoluminescence spectra showed a well defined peak at 428 nm and shoulder around 468 nm for all PbS thin films. The electrical resistivity of the thin films found in the order of 103 Ω cm at room temperature and decreased as the ETA molar concentration was increased.

Investigation of Climate Change Impact on Water Resources for an Alpine Basin in Northern Italy: Implications for Evapotranspiration Modeling Complexity

PubMed Central

Ravazzani, Giovanni; Ghilardi, Matteo; Mendlik, Thomas; Gobiet, Andreas; Corbari, Chiara; Mancini, Marco

2014-01-01

Assessing the future effects of climate change on water availability requires an understanding of how precipitation and evapotranspiration rates will respond to changes in atmospheric forcing. Use of simplified hydrological models is required beacause of lack of meteorological forcings with the high space and time resolutions required to model hydrological processes in mountains river basins, and the necessity of reducing the computational costs. The main objective of this study was to quantify the differences between a simplified hydrological model, which uses only precipitation and temperature to compute the hydrological balance when simulating the impact of climate change, and an enhanced version of the model, which solves the energy balance to compute the actual evapotranspiration. For the meteorological forcing of future scenario, at-site bias-corrected time series based on two regional climate models were used. A quantile-based error-correction approach was used to downscale the regional climate model simulations to a point scale and to reduce its error characteristics. The study shows that a simple temperature-based approach for computing the evapotranspiration is sufficiently accurate for performing hydrological impact investigations of climate change for the Alpine river basin which was studied. PMID:25285917

Investigation of climate change impact on water resources for an Alpine basin in northern Italy: implications for evapotranspiration modeling complexity.

PubMed

Ravazzani, Giovanni; Ghilardi, Matteo; Mendlik, Thomas; Gobiet, Andreas; Corbari, Chiara; Mancini, Marco

2014-01-01

Assessing the future effects of climate change on water availability requires an understanding of how precipitation and evapotranspiration rates will respond to changes in atmospheric forcing. Use of simplified hydrological models is required because of lack of meteorological forcings with the high space and time resolutions required to model hydrological processes in mountains river basins, and the necessity of reducing the computational costs. The main objective of this study was to quantify the differences between a simplified hydrological model, which uses only precipitation and temperature to compute the hydrological balance when simulating the impact of climate change, and an enhanced version of the model, which solves the energy balance to compute the actual evapotranspiration. For the meteorological forcing of future scenario, at-site bias-corrected time series based on two regional climate models were used. A quantile-based error-correction approach was used to downscale the regional climate model simulations to a point scale and to reduce its error characteristics. The study shows that a simple temperature-based approach for computing the evapotranspiration is sufficiently accurate for performing hydrological impact investigations of climate change for the Alpine river basin which was studied.

HUBBLE SHOWS EXPANSION OF ETA CARINAE DEBRIS

NASA Technical Reports Server (NTRS)

2002-01-01

The furious expansion of a huge, billowing pair of gas and dust clouds are captured in this NASA Hubble Space Telescope comparison image of the supermassive star Eta Carinae. To create the picture, astronomers aligned and subtracted two images of Eta Carinae taken 17 months apart (April 1994, September 1995). Black represents where the material was located in the older image, and white represents the more recent location. (The light and dark streaks that make an 'X' pattern are instrumental artifacts caused by the extreme brightness of the central star. The bright white region at the center of the image results from the star and its immediate surroundings being 'saturated' in one of the images.)Photo Credit: Jon Morse (University of Colorado), Kris Davidson (University of Minnesota), and NASA Image files in GIF and JPEG format and captions may be accessed on Internet via anonymous ftp from oposite.stsci.edu in /pubinfo.

Monitoring cropland evapotranspiration using MODIS products in Southern Brazil

NASA Astrophysics Data System (ADS)

Ruhoff, Anderson; Aparecida Moreira, Adriana; de Arruda Souza, Vanessa; Roberti, Debora Regina

2017-04-01

Evapotranspiration (ET), including water loss from plant transpiration and land evaporation, is of vital importance for understanding hydrological processes and climate dynamics. In this context, remote sensing is considered as the most important tool for estimate ET over large areas. The Moderate Resolution Imaging Spectroradiometer (MODIS) offers an interesting opportunity to evaluate ET with spatial resolution of 1 km. The MODIS global evapotranspiration algorithm (MOD16) considers both surface energy fluxes and climatic constraints on ET (water or temperature stress) to estimate plant transpiration and soil evaporation based on Penman-Monteith equation. The algorithm is driven by remotely sensed and reanalysis meteorological data. In this study, MOD16 algorithm was applied to the State of Rio Grande do Sul (in Southern Brazil) to analyse cropland and natural vegetation evapotranspiration and its impacts during drought events. We validated MOD16 estimations using eddy correlation measurements and water balance closure at monthly and annual time scales. We used observed discharge data from three large rivers in Southern Brazil (Jacuí, Taquari and Ibicuí), precipitation data from TRMM Multi-satellite Precipitation Analysis (3B43 version 7) and terrestrial water storage estimations from the Gravity Recovery and climate Experiment (GRACE). MOD16 algorithm detected evapotranspiration in different land use and land cover conditions. In cropland areas, the average evapotranspiration was 705 mm/y, while in pasture/grassland was 750 mm/y and in forest areas was 1099 mm/y. Compared to the annual water balance, evapotranspiration was underestimated, with mean relative errors between 8 and 30% and coefficients of correlation between 0.42 to 0.53. The water storage change (dS/dt) computed from the water balance closure at monthly time scales showed a significant correlation with the terrestrial water storage obtained from GRACE data, with a coefficient of correlation of 0

Adequacy of selected evapotranspiration approximations for hydrologic simulation

USGS Publications Warehouse

Sumner, D.M.

2006-01-01

Evapotranspiration (ET) approximations, usually based on computed potential ET (PET) and diverse PET-to-ET conceptualizations, are routinely used in hydrologic analyses. This study presents an approach to incorporate measured (actual) ET data, increasingly available using micrometeorological methods, to define the adequacy of ET approximations for hydrologic simulation. The approach is demonstrated at a site where eddy correlation-measured ET values were available. A baseline hydrologic model incorporating measured ET values was used to evaluate the sensitivity of simulated water levels, subsurface recharge, and surface runoff to error in four ET approximations. An annually invariant pattern of mean monthly vegetation coefficients was shown to be most effective, despite the substantial year-to-year variation in measured vegetation coefficients. The temporal variability of available water (precipitation minus ET) at the humid, subtropical site was largely controlled by the relatively high temporal variability of precipitation, benefiting the effectiveness of coarse ET approximations, a result that is likely to prevail at other humid sites.

Endothelin ETA receptor expression in human cerebrovascular smooth muscle cells.

PubMed

Yu, J C; Pickard, J D; Davenport, A P

1995-11-01

1. Endothelin (ET) has been implicated in cerebrovasospasm for example, following subarachnoid haemorrhage, and blocking the interaction of ET with its receptors on cerebral vessels, may be of therapeutic benefit. The aim of our study was to characterize endothelin receptor sub-types on medial smooth muscle cells of human cerebral vessels. Cultures of vascular smooth muscle cells were explanted from human cerebral resistance vessels and characterized as human brain smooth muscle cells (HBSMCs). 2. Over a 48 h incubation period, HBSMC cultures secreted comparable levels of immunoreactive (IR) big endothelin-1 (big ET-1) and IR endothelin (ET): 12.7 +/- 10.3 and 8.3 +/- 5.6 pmol/10(6) cells, respectively (mean +/- s.e. mean from three different individuals), into the culture medium. 3. Total RNA was extracted from cultures of human brain smooth muscle cells. Reverse-transcriptase polymerase chain reaction (RI-PCR) assays and subsequent product separation by agarose gel electrophoresis revealed single bands corresponding to the expected product sizes encoding cDNA for ETA (299 base pairs) and ETB (428 base pairs) (n = 3 different cultures). 4. Autoradiography demonstrated the presence of specific binding sites for [125I]-ET-1 which labels all ET receptors, and [125I]-PD151242, an ETA subtype-selective antagonist which exclusively labels ETA receptors, but no specific-binding was detected using ETB subtype-selective [125I]-BQ3020 (n = 3 different cultures, in duplicate). 5. In saturation binding assays, [123I]-ET-1 bound with high affinity: KD = 0.8 +/- 0.1 nM and Bmax = 690 +/- 108 fmol mg-1. A one-site fit was preferred and Hill slopes were close to unity over the concentration range (10(-12) to 10(-8) M). [125I]-PD151242 also bound with similar affinity: KD = 0.4 +/- 0.1 nM and Bmax = 388 +/- 68 fmol mg-1 (mean +/- s.e. mean, n = 3 different cultures). Again, a one-site fit was preferred and Hill slopes were close to unity over the concentration range. Unlabelled PD

Chaperonin containing T-complex polypeptide subunit eta is a potential marker of joint contracture: an experimental study in the rat.

PubMed

He, Ronghan; Wang, Zhe; Lu, Yunxiang; Huang, Junqi; Ren, Jianhua; Wang, Kun

2015-11-01

Joint contracture is a fibroproliferative disorder that restricts joint mobility, resulting in tissue degeneration and deformity. However, the etiology of joint contracture is still unknown. Chaperonin containing T-complex polypeptide subunit eta (CCT-eta) is reported to increase in fibrotic diseases. The purpose of this study was to investigate whether CCT-eta is implicated in joint contracture and to determine the role of CCT-eta in the progression of joint contracture by analyzing a rat model. We immobilized the left knee joint of rat by internal fixation for 8 weeks. The non-immobilized right leg served as a control. The range of motion (ROM) of the knee was investigated. Fibroblasts were obtained from the posterior joint capsule of the joints. The outcome was followed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, fibroblast migration assay, and collagen assay. The effect of CCT-eta on the functions of fibroblasts was observed by utilizing a short inhibitory RNA (siRNA) targeting CCT-eta. The ROM of the immobilized joints was significantly limited compared to the contralateral joints (p < 0.05). Fibroblasts derived from the contractive joints showed higher mRNA and protein expressions of CCT-eta in parallel with alpha-smooth muscle actin (α-SMA) compared to the cells from the contralateral knees (p < 0.05). siRNA-mediated downregulation of CCT-eta inhibited the expressions of both CCT-eta and α-SMA. Moreover, the reduction of CCT-eta also significantly decreased fibroblast functions such as cell mobility and collagen synthesis (all p < 0.05). Our findings indicate that CCT-eta appears to be a potential marker of joint contracture disease.

Examining the sensitivity of modelled evapotranspiration to vegetation structural characteristics within boreal peatlands, riparian ecosystems and upland mixedwood forest

NASA Astrophysics Data System (ADS)

Petrone, R. M.; Chasmer, L. E.; Brown, S. M.; Mendoza, C. A.; Diiwu, J.; Quinton, W. L.; Hopkinson, C.; Devito, K. J.

2010-12-01

The Western Boreal Plain (WBP) of northern Alberta is comprised of a complex mosaic of small ponds, riparian buffer zones, and upland aspen dominated mixedwood forests surrounded by low-lying peatlands. The hydrology of the WBP is strongly influenced by climatic drivers and geology, whereby water budgets are often controlled by vertical fluxes. During most years, potential evapotranspiration (PET) exceeds precipitation (P), and changes in P as a result of climatic change will likely alter actual evapotranspiration (AET) and regional water balances. In recent years, the WBP has also undergone intense anthropogenic disturbance via oil and gas exploration and extraction, and silvicultural and forest harvesting activities. The extent to which changes in land cover types/characteristics affect estimates of PET and AET is currently unknown. This study examines the sensitivity of PET using a simple estimate of equilibrium ET (Priestley-Taylor) and AET (Penman-Monteith variant) to variability in canopy structural and ground surface characteristics at 12 sites throughout the 2008 growing season (June, July, August). Energy balance meteorological stations are deployed within four peatland ecosystems, four riparian buffer zones, two regenerating upland mixedwood forests and two mature upland mixedwood forests. Airborne Light Detection and Ranging (LiDAR) is used to derive metrics of canopy height, leaf area index (LAI), uplands and lowlands, elevation, zero plane displacement, roughness length governing momentum, roughness length governing heat and vapour, and understory vegetation characteristics. LiDAR land surface metrics and energy balance measurements are used to model evapotranspiration for classified land cover types throughout the larger basin. Sensitivity of potential and actual estimates to changes in land cover characteristics within each of the three land cover types (peatland, riparian and upland) is quantified.

Chandra X-Ray Observatory Image of Eta Carinae

NASA Technical Reports Server (NTRS)

1999-01-01

This Chandra X-Ray Observatory image of the mysterious superstar Eta Carinae reveals a surprising hot irner core, creating more questions than answers for astronomers. The image shows three distinct structures: An outer, horseshoe shaped ring about 2 light-years in diameter, a hot inner core about 3 light-months in diameter, and a hot central source less than a light-month in diameter which may contain the superstar. In 1 month, light travels a distance of approximately 489 billion miles (about 788 billion kilometers). All three structures are thought to represent shock waves produced by matter rushing away from the superstar at supersonic speeds. The temperature of the shock-heated gas ranges from 60 million degrees Kelvin in the central regions to 7 million degrees Kelvin on the outer structure. Eta Carinae is one of the most enigmatic and intriguing objects in our galaxy. Between 1837 and 1856, it increased dramatically in brightness to become the most prominent star in the sky except for Sirius, even through it is 7,500 light-years away, more than 80 times the distance to Sirius. This 'Great Eruption,' as it is called, had an energy comparable to a supernova, yet did not destroy the star, which faded to become a dim star, invisible to the naked eye. Since 1940, Eta Carinae has begun to brighten again, becoming visible to the naked eye. Photo credit: NASA/CXC/SAO

Encounter risk analysis of rainfall and reference crop evapotranspiration in the irrigation district

NASA Astrophysics Data System (ADS)

Zhang, Jinping; Lin, Xiaomin; Zhao, Yong; Hong, Yang

2017-09-01

Rainfall and reference crop evapotranspiration are random but mutually affected variables in the irrigation district, and their encounter situation can determine water shortage risks under the contexts of natural water supply and demand. However, in reality, the rainfall and reference crop evapotranspiration may have different marginal distributions and their relations are nonlinear. In this study, based on the annual rainfall and reference crop evapotranspiration data series from 1970 to 2013 in the Luhun irrigation district of China, the joint probability distribution of rainfall and reference crop evapotranspiration are developed with the Frank copula function. Using the joint probability distribution, the synchronous-asynchronous encounter risk, conditional joint probability, and conditional return period of different combinations of rainfall and reference crop evapotranspiration are analyzed. The results show that the copula-based joint probability distributions of rainfall and reference crop evapotranspiration are reasonable. The asynchronous encounter probability of rainfall and reference crop evapotranspiration is greater than their synchronous encounter probability, and the water shortage risk associated with meteorological drought (i.e. rainfall variability) is more prone to appear. Compared with other states, there are higher conditional joint probability and lower conditional return period in either low rainfall or high reference crop evapotranspiration. For a specifically high reference crop evapotranspiration with a certain frequency, the encounter risk of low rainfall and high reference crop evapotranspiration is increased with the decrease in frequency. For a specifically low rainfall with a certain frequency, the encounter risk of low rainfall and high reference crop evapotranspiration is decreased with the decrease in frequency. When either the high reference crop evapotranspiration exceeds a certain frequency or low rainfall does not exceed a

Measurement of {pi}{sup -}p{yields}{eta}n from threshold to p{sub {pi}}{sub {sup -}}=747 MeV/c

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prakhov, S.; Nefkens, B.M.K.; Clajus, M.

2005-07-01

The differential cross section for {eta} production in reaction {pi}{sup -}p{yields}{eta}n has been measured over the full angular range at seven incident {pi}{sup -} beam momenta from threshold to p{sub {pi}}{sub {sup -}}=747 MeV/c using the Crystal Ball multiphoton spectrometer. The angular distributions are S wave dominated. At 10 MeV/c above threshold, a small D-wave contribution appears that interferes with the main S wave. The total {eta} production cross section {sigma}{sup tot} is obtained by integration of d{sigma}/d{omega}. Starting at threshold, {sigma}{sup tot} rises rapidly, as expected for S-wave-dominated production. The features of the {pi}{sup -}p{yields}{eta}n cross section are strikinglymore » similar to those of the SU(3) flavor-related process K{sup -}p{yields}{eta}{lambda}. Comparison of the {pi}{sup -}p{yields}{eta}n reaction is made with {eta} photoproduction.« less

Eta Carinae: An Astrophysical Laboratory to Study Conditions During the Transition Between a Pseudo-Supernova and a Supernova

NASA Astrophysics Data System (ADS)

McKinnon, Darren; Gull, T. R.; Madura, T.

2014-01-01

A major puzzle in the studies of supernovae is the pseudo-supernova, or the near-supernovae state. It has been found to precede, in timespans ranging from months to years, a number of recently-detected distant supernovae. One explanation of these systems is that a member of a massive binary underwent a near-supernova event shortly before the actual supernova phenomenon. Luckily, we have a nearby massive binary, Eta Carinae, that provides an astrophysical laboratory of a near-analog. The massive, highly-eccentric, colliding-wind binary star system survived a non-terminal stellar explosion in the 1800's, leaving behind the incredible bipolar, 10"x20" Homunculus nebula. Today, the interaction of the binary stellar winds 1") is resolvable by the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). Using HST/STIS, several three-dimensional (3D) data cubes (2D spatial, 1D velocity) have been obtained at selected phases during Eta Carinae's 5.54-year orbital cycle. The data cubes were collected by mapping the central 1-2" at 0.05" intervals with a 52"x0.1" aperture. Selected forbidden lines, that form in the colliding wind regions, provide information on electron density of the shocked regions, the ionization by the hot secondary companion of the primary wind and how these regions change with orbital phase. By applying various analysis techniques to these data cubes, we can compare and measure temporal changes due to the interactions between the two massive winds. The observations, when compared to current 3D hydrodynamic models, provide insight on Eta Carinae's recent mass-loss history, important for determining the current and future states of this likely nearby supernova progenitor.

Estimation of Regional Evapotranspiration Using Remotely Sensed Land Surface Temperature. Part 1: Measurement of Evapotranspiration at the Environmental Research Center and Determination of Priestley-taylor Parameter

NASA Technical Reports Server (NTRS)

Kotada, K.; Nakagawa, S.; Kai, K.; Yoshino, M. M.; Takeda, K.; Seki, K.

1985-01-01

In order to study the distribution of evapotranspiration in the humid region using remote sensing technology, the parameter (alpha) in the Priestley-Taylor model was determined. The daily means of the parameter alpha = 1.14 can be available from summer to autumn and alpha = to approximately 2.0 in winter. The results of the satellite and the airborne sensing done on 21st and 22nd January, 1983, are described. Using the vegetation distribution in the Tsukuba Academic New Town, as well as the radiation temperature obtained by remote sensing and the radiation data observed at the ground surface, the evapotranspiration was calculated for each vegetation type by the Priestley-Taylor method. The daily mean evapotranspiration on 22nd January, 1983, was approximately 0.4 mm/day. The differences in evapotranspiration between the vegetation types were not detectable, because the magnitude of evapotranspiration is very little in winter.

The novel multispecies Fc-specific Pseudomonas exotoxin A fusion protein α-Fc-ETA' enables screening of antibodies for immunotoxin development.

PubMed

Klausz, Katja; Kellner, Christian; Derer, Stefanie; Valerius, Thomas; Staudinger, Matthias; Burger, Renate; Gramatzki, Martin; Peipp, Matthias

2015-03-01

Immunoconjugates that deliver cytotoxic payloads to cancer cells represent a promising class of therapeutic agents which are intensively investigated in various clinical applications. Prerequisites for the generation of effective immunoconjugates are antibodies which efficiently deliver the respective cytotoxic payload. To facilitate the selection of human or mouse antibodies that display favorable characteristics as immunotoxins, we developed a novel Pseudomonas exotoxin A (ETA)-based screening protein. The α-Fc-ETA' consists of a multispecies-specific Fc-binding domain antibody genetically fused to a truncated ETA version (ETA'). α-Fc-ETA' non-covalently bound to human and mouse antibodies but did not form immune complexes with bovine immunoglobulins. In combination with antibodies harboring human or mouse Fc domains α-Fc-ETA' inhibited proliferation of antigen-expressing tumor cells. The cytotoxic effects were strictly antibody dependent and were observed with low α-Fc-ETA' concentrations. Mouse antibodies directed against CD7 and CD317/HM1.24 that previously had been used for the generation of functional recombinant immunotoxins, also showed activity in combination with α-Fc-ETA' by inhibiting growth of antigen-positive myeloma and leukemia cell lines. In contrast, α-kappa-ETA', a similarly designed human kappa light chain-specific fusion protein, was only specifically active in combination with antibodies containing a human kappa light chain. Thus, the novel α-Fc-ETA' fusion protein is broadly applicable in screening antibodies and Fc-containing antibody derivatives from different species to select for candidates with favorable characteristics for immunotoxin development. Copyright © 2015 Elsevier B.V. All rights reserved.

A spatiotemporal clustering model for the Third Uniform California Earthquake Rupture Forecast (UCERF3‐ETAS): Toward an operational earthquake forecast

USGS Publications Warehouse

Field, Edward; Milner, Kevin R.; Hardebeck, Jeanne L.; Page, Morgan T.; van der Elst, Nicholas; Jordan, Thomas H.; Michael, Andrew J.; Shaw, Bruce E.; Werner, Maximillan J.

2017-01-01

We, the ongoing Working Group on California Earthquake Probabilities, present a spatiotemporal clustering model for the Third Uniform California Earthquake Rupture Forecast (UCERF3), with the goal being to represent aftershocks, induced seismicity, and otherwise triggered events as a potential basis for operational earthquake forecasting (OEF). Specifically, we add an epidemic‐type aftershock sequence (ETAS) component to the previously published time‐independent and long‐term time‐dependent forecasts. This combined model, referred to as UCERF3‐ETAS, collectively represents a relaxation of segmentation assumptions, the inclusion of multifault ruptures, an elastic‐rebound model for fault‐based ruptures, and a state‐of‐the‐art spatiotemporal clustering component. It also represents an attempt to merge fault‐based forecasts with statistical seismology models, such that information on fault proximity, activity rate, and time since last event are considered in OEF. We describe several unanticipated challenges that were encountered, including a need for elastic rebound and characteristic magnitude–frequency distributions (MFDs) on faults, both of which are required to get realistic triggering behavior. UCERF3‐ETAS produces synthetic catalogs of M≥2.5 events, conditioned on any prior M≥2.5 events that are input to the model. We evaluate results with respect to both long‐term (1000 year) simulations as well as for 10‐year time periods following a variety of hypothetical scenario mainshocks. Although the results are very plausible, they are not always consistent with the simple notion that triggering probabilities should be greater if a mainshock is located near a fault. Important factors include whether the MFD near faults includes a significant characteristic earthquake component, as well as whether large triggered events can nucleate from within the rupture zone of the mainshock. Because UCERF3‐ETAS has many sources of uncertainty, as

Eta Car: The Good, the Bad and the Ugly of Nebular and Stellar Confusion

NASA Technical Reports Server (NTRS)

Gull, T.R.; Sonneborn, G.; Jensen, A.G.; Nielsen, K.E.; Vieira Kover, G.; Hillier, D.J.

2008-01-01

Observations in the far-UV provide a unique opportunity to investigate the very massive star Eta Car and its hot binary companion, Eta Car B. Eta Car was observed with FUSE over a large portion of the 5.54 year spectroscopic period before and after the 2003.5 minimum. The observed spectrum is defined by strong stellar wind signatures, primarily from Eta Car A, complicated by the strong absorptions of the ejecta surrounding Eta Car plus interstellar absorption. The Homunculus and Little Homunculus are massive bipolar ejecta historically associable with LBV outbursts in the 1840s and the 1890s and are linked to absorptions at -513 and -146 km/s, respectively. The FUSE spectra are confused by the extended nebulosity and thermal drifting of the FUSE co-pointed instruments. Interpretation is further complicated by two B-stars sufficiently close to h Car to be included most of the time in the large FUSE aperture. Followup observations partially succeeded in obtaining spectra of at least one of these B-stars through the smaller apertures, allowing potential separation of the B-star contributions and h Car. A complete analysis of all available spectra is currently underway. Our ultimate goals are to directly detect the hot secondary star if possible with FUSE and to identify the absorption contributions to the overall spectrum especially of the stellar members and the massive ejecta.

Search for bound states of the eta-meson in light nuclei

NASA Technical Reports Server (NTRS)

Chrien, R. E.; Bart, S.; Pile, P.; Sutter, R.; Tsoupas, N.; Funsten, H. O.; Finn, J. M.; Lyndon, C.; Punjabi, V.; Perdrisat, C. F.

1988-01-01

A search for nuclear-bound states of the eta meson was carried out. Targets of lithium, carbon, oxygen, and aluminum were placed in a pion(+) beam at 800 MeV/c. A predicted eta bound state in O-15* (E sub x approx. = 540 MeV) with a width of approx. 9 MeV was not observed. A bound state of a size 1/3 of the predicted cross section would have been seen in this experiment at a confidence level of 3sigma (P is greater than 0.9987).

Validating HYLARSMET: a Hydrologically Consistent Land Surface Model for Soil Moisture and Evapotranspiration Modelling over Southern Africa using Remote Sensing and Meteorological Data

NASA Astrophysics Data System (ADS)

Sinclair, Scott; Pegram, Geoff; Mengitsu, Michael; Everson, Colin

2015-04-01

Timeous knowledge of the spatial distribution of soil moisture and evapotranspiration over a large region in fine detail has great value for coping with two weather extremes: flash floods and droughts, since the state of the wetness of the land surface has a major impact on runoff response. Also, the ability to monitor the wetness of the soil and the actual evapotranspiration over large regions, without having to laboriously take expensive samples, is a bonus for agricultural managers who need to predict crop yields. We present samples of the daily national Soil Moisture and Evapotranspiration estimates on a grid of 7300 locations centred in 12 km squares, then move on to the results of a validation study for soil moisture and evapotranspiration estimated using the PyTOPKAPI hydrological model in Land Surface Modelling mode, a system called HYLARSMET. The HYLARSMET estimates are compared with detailed evapotranspiration and soil moisture measurements made at the Baynesfield experimental farm in the KwaZulu-Natal province of South Africa, run by the University of KZN. The HYLARSMET evapotranspiration estimates compared very well with the measured estimates for the two chosen crop types, in spite of the fact that the HYLARSMET estimates were not designed to explicitly account for the crop types at each site. The same seasonality effects were evident in all 3 estimates, and there was a stronger ET relationship between HYLARSMET and the Soybean site (Pearson r = 0.81) than for Maize, (r = 0.59). The soil moisture relationship was stronger between the two in situ measured estimates (r = 0.98 at 0.5 m depth) than it was between HYLARSMET and the field estimates (r about 0.52 in both cases). Overall there was a reasonably good relationship between HYLARSMET and the in situ measurements of ET and SM at each site, indicating the value of the modelling procedure.

Search for Planetary-mass Companions of the LHB Star eta Corvi

NASA Astrophysics Data System (ADS)

Marengo, Massimo; Lisse, Carey; Stapelfeldt, Karl; Hulsebus, Alan; Sitko, Michael

2016-08-01

The nearby sun-like star eta Corvi (F2V, d = 18 pc, age = 1.2 Gyr) has long been known to possess a bright, dusty Kuiper belt that has been recently resolved with Herschel/PACS. In addition to this structure, eta Corvi is one of the rare mature planetary systems to possess also an inner warm belt (~ 3 AU radius), located within the Terrestrial Habitable Zone (TLZ) of this star. Our characterization of this structure, based on Spitzer/IRS and NASA/IRTF SpeX spectral observations, reveals the signature of ice, organics and silicate dust in this warm belt. This supports the hypothesis that eta Corvi is undergoing a Late Heavy Bombardment (LHB), delivering life-bearing water- and organic-rich material from the Kuiper belt to the TLZ, at roughly the same age as the Solar System?s LHB. For the past four years we have monitored the brightness of eta Corvi?s warm belt with Spitzer/IRAC, finding that its infrared emission has been stable over a multi-year timescale. In 2012 we have also conducted a search for widely separated substellar-mass companions of this star, whose presence as been suggested as a possible trigger for the LHB currently undergoing in the system. This search has led to the identification of three sources with colors and magnitudes consistent with being late-T and Y dwarf companions of this star. We here propose to acquire a new deep roll-subtracted image of the system, 5 years after our first visit, to test for common proper motion of these candidate companions, and determine if any of this sources is physically associated with eta Corvi. A positive identification of a substellar-mass companions (one of which could be a 3-5 MJ planet at ~360 AU from the star) would be a significant step in understanding the processes leading to LHB-like events in a system analogous to the Solar System.

Energy balance in the watershed of Ipê, Northwestern São Paulo State, Brazil

NASA Astrophysics Data System (ADS)

Feitosa, Diego G.; T. Hernandez, Fernando B.; Franco, Renato A. M.; Teixeira, Antonio H. C.; Neale, Christopher M.

2016-10-01

The region of Ilha Solteira, in the Northwestern of São Paulo State, has been undergoing significant changes in agricultural land use and cover since 2006, as pasture fields have been replaced by sugarcane crop. This drastic change can lead to a disturbance in the energy balance, affecting the local climate. The aim of this paper was to assess some parameters related to the energy balance of Ipê's watershed, that changed since no sugarcane cultivation in 2006 to 2,164 hectares in 2011, occupying 31% of the catchment area with this important energy crop for the economy and the environment of Brazil. This study was carried out using remote sensing combined with weather data and using the SAFER (Simple Algorithm for Retrieving Evapotranspiration) model applied in 9 Landsat images collected between 2003 and 2011. The results showed a wide variation between the components of energy balance and when considering only the sugarcane crop were verified the increase values of ETa (Actual Evapotranspiration), H/Rn (Sensible Heat Flux/Net Radiation), TS (Surface Temperature), Rl↑ (Emitted longwave), Rl↓ (Incidente longwave) and surface albedo after the sugarcane production over these years. On the other hand, the NDVI, λE/Rn (Latent Heat Flux/Net Radiation) and Rn values (data) decreased in the same period. Also there was satisfactory correlation between NDVI and ETa. The SAFER model showed satisfactory results for studies of energy balance applied in the Northwestern of São Paulo State.

FINDING {eta} CAR ANALOGS IN NEARBY GALAXIES USING SPITZER. I. CANDIDATE SELECTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Rubab; Stanek, K. Z.; Kochanek, C. S., E-mail: khan@astronomy.ohio-state.edu, E-mail: kstanek@astronomy.ohio-state.edu, E-mail: ckochanek@astronomy.ohio-state.edu

The late-stage evolution of the most massive stars such as {eta} Carinae is controlled by the effects of mass loss, which may be dominated by poorly understood eruptive mass ejections. Understanding this population is challenging because no true analogs of {eta} Car have been clearly identified in the Milky Way or other galaxies. We utilize Spitzer IRAC images of seven nearby ({approx}< 4 Mpc) galaxies to search for such analogs. We find 34 candidates with a flat or rising mid-IR spectral energy distributions toward longer mid-infrared wavelengths that emit >10{sup 5} L{sub Sun} in the IRAC bands (3.6 to 8.0more » {mu}m) and are not known to be background sources. Based on our estimates for the expected number of background sources, we expect that follow-up observations will show that most of these candidates are not dust enshrouded massive stars, with an expectation of only 6 {+-} 6 surviving candidates. Since we would detect true analogs of {eta} Car for roughly 200 years post-eruption, this implies that the rate of eruptions like {eta} Car is less than the core-collapse supernova rate. It is possible, however, that every M > 40 M{sub Sun} star undergoes such eruptions given our initial results. In Paper II we will characterize the candidates through further analysis and follow-up observations, and there is no barrier to increasing the galaxy sample by an order of magnitude. The primary limitation of the present search is that Spitzer's resolution limits us to the shorter wavelength IRAC bands. With the James Webb Space Telescope, such surveys can be carried out at the far more optimal wavelengths of 10-30 {mu}m, allowing identification of {eta} Car analogs for millennia rather than centuries post-eruption.« less

Assessment of actual evapotranspiration over a semiarid heterogeneous land surface by means of coupled low-resolution remote sensing data with an energy balance model: comparison to extra-large aperture scintillometer measurements

NASA Astrophysics Data System (ADS)

Saadi, Sameh; Boulet, Gilles; Bahir, Malik; Brut, Aurore; Delogu, Émilie; Fanise, Pascal; Mougenot, Bernard; Simonneaux, Vincent; Lili Chabaane, Zohra

2018-04-01

In semiarid areas, agricultural production is restricted by water availability; hence, efficient agricultural water management is a major issue. The design of tools providing regional estimates of evapotranspiration (ET), one of the most relevant water balance fluxes, may help the sustainable management of water resources. Remote sensing provides periodic data about actual vegetation temporal dynamics (through the normalized difference vegetation index, NDVI) and water availability under water stress (through the surface temperature Tsurf), which are crucial factors controlling ET. In this study, spatially distributed estimates of ET (or its energy equivalent, the latent heat flux LE) in the Kairouan plain (central Tunisia) were computed by applying the Soil Plant Atmosphere and Remote Sensing Evapotranspiration (SPARSE) model fed by low-resolution remote sensing data (Terra and Aqua MODIS). The work's goal was to assess the operational use of the SPARSE model and the accuracy of the modeled (i) sensible heat flux (H) and (ii) daily ET over a heterogeneous semiarid landscape with complex land cover (i.e., trees, winter cereals, summer vegetables). SPARSE was run to compute instantaneous estimates of H and LE fluxes at the satellite overpass times. The good correspondence (R2 = 0.60 and 0.63 and RMSE = 57.89 and 53.85 W m-2 for Terra and Aqua, respectively) between instantaneous H estimates and large aperture scintillometer (XLAS) H measurements along a path length of 4 km over the study area showed that the SPARSE model presents satisfactory accuracy. Results showed that, despite the fairly large scatter, the instantaneous LE can be suitably estimated at large scales (RMSE = 47.20 and 43.20 W m-2 for Terra and Aqua, respectively, and R2 = 0.55 for both satellites). Additionally, water stress was investigated by comparing modeled (SPARSE) and observed (XLAS) water stress values; we found that most points were located within a 0.2 confidence interval, thus the

A project summary: Water and energy budget assessment for a non-tidal wetland in the Sacramento-San Joaquin delta

USGS Publications Warehouse

Anderson, Frank E.; Snyder, R.L.; Paw, U.K.T.; Drexler, Judith Z.

2004-01-01

The methods used to obtain universal cover coefficient (Kc) values for a non-tidal restored wetland in the Sacramento-San Joaquin river delta, US, during the summer of the year 2002 and to investigate possible differences during changing wind patterns are described. A micrometeorological tower over the wetland was established to quantify actual evapotranspiration (ETa) rates and surface energy fluxes for water and energy budget analysis. The eddy-covariance (EC) system was used to measure the surface energy budget data in the period from May 23 to November 6, 2002. The results show that K c values should be lower during westerly than northerly wind events during the midseason period due to the reduced vapor pressure deficit.

Water balance dynamics in the Nile Basin

USGS Publications Warehouse

Senay, Gabriel B.; Asante, Kwabena; Artan, Guleid A.

2009-01-01

Understanding the temporal and spatial dynamics of key water balance components of the Nile River will provide important information for the management of its water resources. This study used satellite-derived rainfall and other key weather variables derived from the Global Data Assimilation System to estimate and map the distribution of rainfall, actual evapotranspiration (ETa), and runoff. Daily water balance components were modelled in a grid-cell environment at 0·1 degree (∼10 km) spatial resolution for 7 years from 2001 through 2007. Annual maps of the key water balance components and derived variables such as runoff and ETa as a percent of rainfall were produced. Generally, the spatial patterns of rainfall and ETa indicate high values in the upstream watersheds (Uganda, southern Sudan, and southwestern Ethiopia) and low values in the downstream watersheds. However, runoff as a percent of rainfall is much higher in the Ethiopian highlands around the Blue Nile subwatershed. The analysis also showed the possible impact of land degradation in the Ethiopian highlands in reducing ETa magnitudes despite the availability of sufficient rainfall. Although the model estimates require field validation for the different subwatersheds, the runoff volume estimate for the Blue Nile subwatershed is within 7·0% of a figure reported from an earlier study. Further research is required for a thorough validation of the results and their integration with ecohydrologic models for better management of water and land resources in the various Nile Basin ecosystems.

Synthesis and reactivity of bis(tetramethylcyclopentadienyl) yttrium metallocenes including the reduction of Me(3)SiN(3) to [(Me(3)Si)(2)N](-) with [(C(5)Me(4)H)(2)Y(THF)](2)(mu-eta(2):eta(2)-N(2)).

PubMed

Lorenz, Sara E; Schmiege, Benjamin M; Lee, David S; Ziller, Joseph W; Evans, William J

2010-07-19

The metallocene precursors needed to provide the tetramethylcyclopentadienyl yttrium complexes (C(5)Me(4)H)(3)Y, [(C(5)Me(4)H)(2)Y(THF)](2)(mu-eta(2):eta(2)-N(2)), and [(C(5)Me(4)H)(2)Y(mu-H)](2) for reactivity studies have been synthesized and fully characterized, and their reaction chemistry has led to an unexpected conversion of an azide to an amide. (C(5)Me(4)H)(2)Y(mu-Cl)(2)K(THF)(x), 1, synthesized from YCl(3) and KC(5)Me(4)H reacts with allylmagnesium chloride to make (C(5)Me(4)H)(2)Y(eta(3)-C(3)H(5)), 2, which is converted to [(C(5)Me(4)H)(2)Y][(mu-Ph)(2)BPh(2)], 3, with [Et(3)NH][BPh(4)]. Complex 3 reacts with KC(5)Me(4)H to form (C(5)Me(4)H)(3)Y, 4. The reduced dinitrogen complex, [(C(5)Me(4)H)(2)Y(THF)](2)(mu-eta(2):eta(2)-N(2)), 5, can be synthesized from either [(C(5)Me(4)H)(2)Y](2)[(mu-Ph)(2)BPh(2)], 3, or (C(5)Me(4)H)(3)Y, 4, with potassium graphite under a dinitrogen atmosphere. The (15)N labeled analogue, [(C(5)Me(4)H)(2)Y(THF)](2)(mu-eta(2):eta(2)-(15)N(2)), 5-(15)N, has also been prepared, and the (15)N NMR data have been compared to previously characterized reduced dinitrogen complexes. Complex 2 reacts with H(2) to form the corresponding hydride, [(C(5)Me(4)H)(2)Y(mu-H)](2), 6. Complex 5 displays similar reactivity to that of the analogous [(C(5)Me(4)H)(2)Ln(THF)](2)(mu-eta(2):eta(2)-N(2)) complexes (Ln = La, Lu), with substrates such as phenazine, anthracene, and CO(2). In addition, 5 reduces Me(3)SiN(3) to form (C(5)Me(4)H)(2)Y[N(SiMe(3))(2)], 7.

The X-ray Variability of Eta Car, 1996-2010

NASA Technical Reports Server (NTRS)

Corcoran, Michael F.; Hamaguchi, K.; Gull, T.; Owocki, S.; Pittard, J.

2010-01-01

X-ray photometry in the 2-10 keY band of the the supermassive binary star Eta Car has been measured with the Rossi X-ray Timing Explorer from 1996-2010. The ingress to X-ray minimum is consistent with a period of 2024 days. The 2009 X-ray minimum began on January 162009 and showed an unexpectedly abrupt recovery starting after 12 Feb 2009. The X-ray colors become harder about half-way through all three minima and continue until flux recovery. The behavior of the fluxes and X-ray colors for the most recent X-ray minimum, along with Chandra high resolution grating spectra at key phases suggests a significant change in the inner wind of Eta Car, a possible indicator that the star is entering a new unstable phase of mass loss.

Eta Carinae, the Integral Nebula and the Homunculus Observations

NASA Astrophysics Data System (ADS)

Gull, Theodore

2000-07-01

In the past two years, observations of Eta Carina have revealed much new and very exciting information. Augusto Damineli noted a 5.5 year period in the visible and near infrared spectroscopy. Michael Corcoran and Bish Ishibashi noticed modulation of the x-ray fluxes with various periodicities around 90 days before and after the xray and radio minimum in December 1997. Observations, done in March 1998 under proposal 7302 {Davidson et al} from 1640A to 10400A using STIS in GXXXM mode and the 50x0.1 arcsecond slit, revealed much new information in the immediate regions of Eta Carina. The slit orientation was slightly off the major axis of the Homunculus, but passed through Weigelt components B and D. Bish Ishibashi and Ted Gull have reduced the data and provided it to various team members. Torgil Zethson has identified well over 90 percent of the emission lines in the March 1998 spectrum and finds most to be FeII emission lines. Based upon the past ground-based history of Eta Carina, we expected that FeIII and other high ionization states would return within the year. STIS GTO observations {Ted Gull, PI program 8036} characterized a bright internal emission nebula by turning the slit 90 degrees for visit 1 and studying the changes in spectrum as the FeIII lines appear by using visit 2 with the identical slit orientation from March 19, 1998. Data from the four visits of STIS to Eta Carinae between December 1997 and February 1999 demonstrate that the star has brightened by a factor of two during that interval and that the immediate nebulosity has tripled in surface brightness. Moreover a small circular nebular shell, seen in multiple [Fe II] lines has disappeared and the opacity in the 2000 to 3000A region obscuring the star has lifted considerable as the Fe II is converting to Fe III. Given the strong changes in the spectrum, we have chosen to use the six orbits in two visits. Visit 1 will be a precise repeat of the March 1998 and February 1999 observations, adjusted

Simple analytical model of evapotranspiration in the presence of roots.

PubMed

Cejas, Cesare M; Hough, L A; Castaing, Jean-Christophe; Frétigny, Christian; Dreyfus, Rémi

2014-10-01

Evaporation of water out of a soil involves complicated and well-debated mechanisms. When plant roots are added into the soil, water transfer between the soil and the outside environment is even more complicated. Indeed, plants provide an additional process of water transfer. Water is pumped by the roots, channeled to the leaf surface, and released into the surrounding air by a process called transpiration. Prediction of the evapotranspiration of water over time in the presence of roots helps keep track of the amount of water that remains in the soil. Using a controlled visual setup of a two-dimensional model soil consisting of monodisperse glass beads, we perform experiments on actual roots grown under different relative humidity conditions. We record the total water mass loss in the medium and the position of the evaporating front that forms within the medium. We then develop a simple analytical model that predicts the position of the evaporating front as a function of time as well as the total amount of water that is lost from the medium due to the combined effects of evaporation and transpiration. The model is based on fundamental principles of evaporation fluxes and includes empirical assumptions on the quantity of open stomata in the leaves, where water transpiration occurs. Comparison between the model and experimental results shows excellent prediction of the position of the evaporating front as well as the total mass loss from evapotranspiration in the presence of roots. The model also provides a way to predict the lifetime of a plant.

An Aboriginal Australian Record of the Great Eruption of Eta Carinae

NASA Astrophysics Data System (ADS)

Hamacher, Duane W.; Frew, David J.

2010-11-01

We present evidence that the Boorong Aboriginal people of northwestern Victoria observed the Great Eruption of Eta Carinae in the nineteenth century and incorporated this event into their oral traditions. We identify this star, as well as others not specifically identified by name, using descriptive material presented in the 1858 paper by William Edward Stanbridge in conjunction with early southern star catalogues. This identification of a transient astronomical event supports the assertion that Aboriginal oral traditions are dynamic and evolving, and not static. This is the only definitive indigenous record of Eta Carinae's outburst identified in the literature to date.

Measurement of the branching ratio of a rare decay {eta}{yields}{pi}{sup 0}{gamma}{gamma} with WASA-at-COSY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lalwani, Kavita

2011-10-24

In this paper we present the preliminary results on the measurement of the branching ratio of a rare decay {eta}{yields}{pi}{sup 0}{gamma}{gamma} with the WASA Detector at COSY. We have used a sample of 10{sup 7}{eta} mesons produced at the COSY ring using the pd{yields}{sup 3}He{eta} reaction close to threshold. We detail the intricate extraction of the signal, which has about 360{+-}70(stat){eta}{yields}{pi}{sup 0}{gamma}{gamma} events, from the overwhelming background channels for example {eta}{yields}3{pi}{sup 0}, pd{yields}{sup 3}He 3{pi}{sup 0} and pd{yields}{sup 3}He 2{pi}{sup 0}.

Testing an Energy Balance Model for Estimating Actual Evapotranspiration Using Remotely Sensed Data. [Hannover, West Germany barley and wheat fields

NASA Technical Reports Server (NTRS)

Gurney, R. J.; Camillo, P. J.

1985-01-01

An energy-balance model is used to estimate daily evapotranspiration for 3 days for a barley field and a wheat field near Hannover, Federal Republic of Germany. The model was calibrated using once-daily estimates of surface temperatures, which may be remotely sensed. The evaporation estimates were within the 95% error bounds of independent eddy correlation estimates for the daytime periods for all three days for both sites, but the energy-balance estimates are generally higher; it is unclear which estimate is biassed. Soil moisture in the top 2 cm of soil, which may be remotely sensed, may be used to improve these evaporation estimates under partial ground cover. Sensitivity studies indicate the amount of ground data required is not excessive.

Estimation of land surface evapotranspiration with A satellite remote sensing procedure

USGS Publications Warehouse

Irmak, A.; Ratcliffe, I.; Ranade, P.; Hubbard, K.G.; Singh, Ramesh K.; Kamble, B.; Kjaersgaard, J.

2011-01-01

There are various methods available for estimating magnitude and trends of evapotranspiration. Bowen ratio energy balance system and eddy correlation techniques offer powerful alternatives for measuring land surface evapotranspiration. In spite of the elegance, high accuracy, and theoretical attractions of these techniques for measuring evapotranspiration, their practical use over large areas can be limited due to the number of sites needed and the related expense. Application of evapotranspiration mapping from satellite measurements can overcome the limitations. The objective of this study was to utilize the METRICTM (Mapping Evapotranspiration at High Resolution using Internalized Calibration) model in Great Plains environmental settings to understand water use in managed ecosystems on a regional scale. We investigated spatiotemporal distribution of a fraction of reference evapotranspiration (ETrF) using eight Landsat 5 images during the 2005 and 2006 growing season for path 29, row 32. The ETrF maps generated by METRICTM allowed us to follow the magnitude and trend in ETrF for major land-use classes during the growing season. The ETrF was lower early in the growing season for agricultural crops and gradually increased as the normalized difference vegetation index of crops increased, thus presenting more surface area over which water could transpire toward the midseason. Comparison of predictions with Bowen ratio energy balance system measurements at Clay Center, NE, showed that METRICTM performed well at the field scale for predicting evapotranspiration from a cornfield. If calibrated properly, the model could be a viable tool to estimate water use in managed ecosystems in subhumid climates at a large scale.

Experimental and molecular dynamics simulation study of the sublimation and vaporization energetics of iron metalocenes. crystal structures of Fe(eta5-C5H4CH3)2 and Fe[(eta5-(C5H5)(eta5-C5H4CHO)].

PubMed

Lousada, Claudio M; Pinto, Susana S; Lopes, José N Canongia; da Piedade, M Fatima Minas; Diogo, Hermínio P; da Piedade, Manuel E Minas

2008-04-03

The standard molar enthalpies of sublimation of ferrocene, 1,1'-dimethylferrocene, decamethylferrocene, ferrocenecarboxaldehyde and alpha-methylferrocenemethanol, and the enthalpy of vaporization of N,N-dimethyl(aminomethyl)ferrocene, at 298.15 K, were determined by Calvet-drop microcalorimetry and/or the Knudsen effusion method. The obtained values were used to assess and refine our previously developed force field for metallocenes. The modified force field was able to reproduce the deltasubHdegreesm and deltavapHdegreesm values of the test-set with an accuracy better than 5 kJ.mol-1, except for decamethylferrocene, in which case the deviation between the calculated and experimental deltasubHdegreesm values was 16.1 kJ.mol-1. The origin of the larger error found in the prediction of the sublimation energetics of decamethylferrocene, and which was also observed in the estimation of structural properties (e.g., density and unit cell dimensions), is discussed. Finally, the crystal structures of Fe(eta5-C5H4CH3)2 and Fe[(eta5-(C5H5)(eta5-C5H4CHO)] at 293 and 150 K, respectively, are reported.

Low Evapotranspiration Enhances the Resilience of Peatland Carbon Stocks to Fire

NASA Astrophysics Data System (ADS)

Kettridge, N.; Lukenbach, M. C.; Hokanson, K. J.; Hopkinson, C.; Devito, K. J.; Petrone, R. M.; Mendoza, C. A.; Waddington, J. M.

2017-09-01

Boreal peatlands may be vulnerable to projected changes in the wildfire regime under future climates. Extreme drying during the sensitive postfire period may exceed peatland ecohydrological resilience, triggering long-term degradation of these globally significant carbon stocks. Despite these concerns, we show low peatland evapotranspiration at both the plot- and landscape-scale postfire, in water-limited peatlands dominated by feather moss that are ubiquitous across continental western Canada. Low postfire evapotranspiration enhances the resilience of carbon stocks in such peatlands to wildfire disturbance and reinforces their function as a regional source of water. Near-surface water repellency may provide an important, previously unexplored, regulator of peatland evapotranspiration that can induce low evapotranspiration in the initial postfire years by restricting the supply of water to the peat surface.

Realization of daily evapotranspiration in arid ecosystems based on remote sensing techniques

NASA Astrophysics Data System (ADS)

Elhag, Mohamed; Bahrawi, Jarbou A.

2017-03-01

Daily evapotranspiration is a major component of water resources management plans. In arid ecosystems, the quest for an efficient water budget is always hard to achieve due to insufficient irrigational water and high evapotranspiration rates. Therefore, monitoring of daily evapotranspiration is a key practice for sustainable water resources management, especially in arid environments. Remote sensing techniques offered a great help to estimate the daily evapotranspiration on a regional scale. Existing open-source algorithms proved to estimate daily evapotranspiration comprehensively in arid environments. The only deficiency of these algorithms is the course scale of the used remote sensing data. Consequently, the adequate downscaling algorithm is a compulsory step to rationalize an effective water resources management plan. Daily evapotranspiration was estimated fairly well using an Advance Along-Track Scanner Radiometer (AATSR) in conjunction with (MEdium Resolution Imaging Spectrometer) MERIS data acquired in July 2013 with 1 km spatial resolution and 3 days of temporal resolution under a surface energy balance system (SEBS) model. Results were validated against reference evapotranspiration ground truth values using standardized Penman-Monteith method with R2 of 0.879. The findings of the current research successfully monitor turbulent heat fluxes values estimated from AATSR and MERIS data with a temporal resolution of 3 days only in conjunction with reliable meteorological data. Research verdicts are necessary inputs for a well-informed decision-making processes regarding sustainable water resource management.

USING MM5V3 WITH ETA ANALYSES FOR AIR-QUALITY MODELING AT THE EPA

EPA Science Inventory

Efforts have been underway since MM5v3 was released in July 1999 to set up air-quality simulations using Eta analyses as background fields. Our previous simulations used a one-way quadruple-nested set of domains with horizontal grid spacing of 108, 36, 12 and 4 km. With Eta a...

Expected Increase of Activity of Eta Aquariids Meteor Shower

NASA Astrophysics Data System (ADS)

Kulikova, N. V.; Chepurova, V. M.

2018-04-01

Analysis of the results of modeling disintegration of Comet 1P/Halley after its flare in 1991 has allowed us to predict an increase of the activity of the associated Eta Aquariids meteor shower in April-May 2018.

Drought impacts and resilience on crops via evapotranspiration estimations

NASA Astrophysics Data System (ADS)

Timmermans, Joris; Asadollahi Dolatabad, Saeid

2015-04-01

Currently, the global needs for food and water is at a critical level. It has been estimated that 12.5 % of the global population suffers from malnutrition and 768 million people still do not have access to clean drinking water. This need is increasing because of population growth but also by climate change. Changes in precipitation patterns will result either in flooding or droughts. Consequently availability, usability and affordability of water is becoming challenge and efficient use of water and water management is becoming more important, particularly during severe drought events. Drought monitoring for agricultural purposes is very hard. While meteorological drought can accurately be monitored using precipitation only, estimating agricultural drought is more difficult. This is because agricultural drought is dependent on the meteorological drought, the impacts on the vegetation, and the resilience of the crops. As such not only precipitation estimates are required but also evapotranspiration at plant/plot scale. Evapotranspiration (ET) describes the amount of water evaporated from soil and vegetation. As 65% of precipitation is lost by ET, drought severity is highly linked with this variable. In drought research, the precise quantification of ET and its spatio-temporal variability is therefore essential. In this view, remote sensing based models to estimate ET, such as SEBAL and SEBS, are of high value. However the resolution of current evapotranspiration products are not good enough for monitoring the impact of the droughts on the specific crops. This limitation originates because plot scales are in general smaller than the resolution of the available satellite ET products. As such remote sensing estimates of evapotranspiration are always a combination of different land surface types and cannot be used for plant health and drought resilience studies. The goal of this research is therefore to enable adequate resolutions of daily evapotranspiration estimates

$eta$ production at high Q^2

DOE Office of Scientific and Technical Information (OSTI.GOV)

M.K. Jones

2012-04-01

The differential cross-sections for the p(e,e'p){eta} reaction have been measured in Hall C at Jefferson Lab at Q{sup 2} = 5.7 and 7.0 (GeV/c){sup 2} for center-of-mass energies from threshold to 1.8 GeV, encompassing the S{sub 11}(1535) resonance, which dominates the reaction. From fits to the data, the S{sub 11}(1535) helicity conserving photo-coupling amplitude, A{sub 1/2}, was extracted.

Increased CCT-eta expression is a marker of latent and active disease and a modulator of fibroblast contractility in Dupuytren's contracture.

PubMed

Satish, Latha; O'Gorman, David B; Johnson, Sandra; Raykha, Christina; Gan, Bing Siang; Wang, James H-C; Kathju, Sandeep

2013-07-01

Dupuytren's contracture (DC) is a fibroproliferative disorder of unknown etiology characterized by a scar-like contracture that develops in the palm and/or digits. We have previously reported that the eta subunit of the chaperonin containing T-complex polypeptide (CCT-eta) is increased in fibrotic wound healing, and is essential for the accumulation of α-smooth muscle actin (α-SMA) in fibroblasts. The purpose of this study was to determine if CCT-eta is similarly implicated in the aberrant fibrosis seen in DC and to investigate the role of CCT-eta in the behavior of myo/fibroblasts in DC. Fibroblasts were obtained from DC-affected palmar fascia, from adjacent phenotypically normal palmar fascia in the same DC patients (PF), and from non-DC palmar fascial tissues in patients undergoing carpal tunnel (CT) release. Inherent contractility in these three populations was examined using fibroblast-populated collagen lattices (FPCLs) and by cell traction force microscopy. Expression of CCT-eta and α-SMA protein was determined by Western blot. The effect of CCT-eta inhibition on the contractility of DC cells was determined by deploying an siRNA versus CCT-eta. DC cells were significantly more contractile than both matching palmar fascial (PF) cells and CT cells in both assays, with PF cells demonstrating an intermediate contractility in the FPCL assay. Whereas α-SMA protein was significantly increased only in DC cells compared to PF and CT cells, CCT-eta protein was significantly increased in both PF and DC cells compared to CT cells. siRNA-mediated depletion of CCT-eta inhibited the accumulation of both CCT-eta and α-SMA protein in DC cells, and also significantly decreased the contractility of treated DC cells. These observations suggest that increased expression of CCT-eta appears to be a marker for latent and active disease in these patients and to be essential for the increased contractility exhibited by these fibroblasts.

Observations of Orionids and eta-Aquariids in 2006 from Bulgaria

NASA Astrophysics Data System (ADS)

Bozhurova, Eva; Zhivkova, Desislava

2010-12-01

We present observations of the eta-Aquariid and Orionid meteor showers collected during observing expeditions. The 2006 May 4-6 expedition with two observers yielded 63 meteors in 4.14 h of total effective observing time. A radiant was derived from 34 eta-Aquariids. The October campaign surprised all observers with the unusually high Orionid activity about twice as high as the average. In our analysis we include observing data of Boris Stoilov (STOBO), Natasha Ivanova (IVANA) and Ivan Gradinarov (GRAIV). Based on 107 recorded meteors from which 47 were Orionids seen in 9.8 total effective time for the night of 21/22 October, we obtained a mean ZHR equal to 41.5 assuming a population index r = 2.0.

Neutral decays of {eta}{sup '} at WASA-at-COSY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duniec, David; Jany, Benedykt R.; IKP-2 Forschungszentrum Juelich, 52428 Juelich

2007-11-07

The status and some of the goals of the {eta}{sup '} physics program at WASA-at-COSY with regards to neutral hadronic decays are presented. Very preliminary results of a test run from WASA-at-COSY in May 2007 are presented.

Recent decline in the global land evapotranspiration trend due to limited moisture supply.

PubMed

Jung, Martin; Reichstein, Markus; Ciais, Philippe; Seneviratne, Sonia I; Sheffield, Justin; Goulden, Michael L; Bonan, Gordon; Cescatti, Alessandro; Chen, Jiquan; de Jeu, Richard; Dolman, A Johannes; Eugster, Werner; Gerten, Dieter; Gianelle, Damiano; Gobron, Nadine; Heinke, Jens; Kimball, John; Law, Beverly E; Montagnani, Leonardo; Mu, Qiaozhen; Mueller, Brigitte; Oleson, Keith; Papale, Dario; Richardson, Andrew D; Roupsard, Olivier; Running, Steve; Tomelleri, Enrico; Viovy, Nicolas; Weber, Ulrich; Williams, Christopher; Wood, Eric; Zaehle, Sönke; Zhang, Ke

2010-10-21

More than half of the solar energy absorbed by land surfaces is currently used to evaporate water. Climate change is expected to intensify the hydrological cycle and to alter evapotranspiration, with implications for ecosystem services and feedback to regional and global climate. Evapotranspiration changes may already be under way, but direct observational constraints are lacking at the global scale. Until such evidence is available, changes in the water cycle on land−a key diagnostic criterion of the effects of climate change and variability−remain uncertain. Here we provide a data-driven estimate of global land evapotranspiration from 1982 to 2008, compiled using a global monitoring network, meteorological and remote-sensing observations, and a machine-learning algorithm. In addition, we have assessed evapotranspiration variations over the same time period using an ensemble of process-based land-surface models. Our results suggest that global annual evapotranspiration increased on average by 7.1 ± 1.0 millimetres per year per decade from 1982 to 1997. After that, coincident with the last major El Niño event in 1998, the global evapotranspiration increase seems to have ceased until 2008. This change was driven primarily by moisture limitation in the Southern Hemisphere, particularly Africa and Australia. In these regions, microwave satellite observations indicate that soil moisture decreased from 1998 to 2008. Hence, increasing soil-moisture limitations on evapotranspiration largely explain the recent decline of the global land-evapotranspiration trend. Whether the changing behaviour of evapotranspiration is representative of natural climate variability or reflects a more permanent reorganization of the land water cycle is a key question for earth system science.

Accuracy assessment of NOAA gridded daily reference evapotranspiration for the Texas High Plains

USGS Publications Warehouse

Moorhead, Jerry; Gowda, Prasanna H.; Hobbins, Michael; Senay, Gabriel; Paul, George; Marek, Thomas; Porter, Dana

2015-01-01

The National Oceanic and Atmospheric Administration (NOAA) provides daily reference evapotranspiration (ETref) maps for the contiguous United States using climatic data from North American Land Data Assimilation System (NLDAS). This data provides large-scale spatial representation of ETref, which is essential for regional scale water resources management. Data used in the development of NOAA daily ETref maps are derived from observations over surfaces that are different from short (grass — ETos) or tall (alfalfa — ETrs) reference crops, often in nonagricultural settings, which carries an unknown discrepancy between assumed and actual conditions. In this study, NOAA daily ETos and ETrs maps were evaluated for accuracy, using observed data from the Texas High Plains Evapotranspiration (TXHPET) network. Daily ETos, ETrs and the climatic data (air temperature, wind speed, and solar radiation) used for calculating ETref were extracted from the NOAA maps for TXHPET locations and compared against ground measurements on reference grass surfaces. NOAA ETrefmaps generally overestimated the TXHPET observations (1.4 and 2.2 mm/day ETos and ETrs, respectively), which may be attributed to errors in the NLDAS modeled air temperature and wind speed, to which reference ETref is most sensitive. Therefore, a bias correction to NLDAS modeled air temperature and wind speed data, or adjustment to the resulting NOAA ETref, may be needed to improve the accuracy of NOAA ETref maps.

Daily reference crop evapotranspiration with reduced data sets in the humid environments of Azores islands using estimates of actual vapor pressure, solar radiation, and wind speed

NASA Astrophysics Data System (ADS)

Paredes, P.; Fontes, J. C.; Azevedo, E. B.; Pereira, L. S.

2017-11-01

Reference crop evapotranspiration (ETo) estimations using the FAO Penman-Monteith equation (PM-ETo) require a set of weather data including maximum and minimum air temperatures (T max, T min), actual vapor pressure (e a), solar radiation (R s), and wind speed (u 2). However, those data are often not available, or data sets are incomplete due to missing values. A set of procedures were proposed in FAO56 (Allen et al. 1998) to overcome these limitations, and which accuracy for estimating daily ETo in the humid climate of Azores islands is assessed in this study. Results show that after locally and seasonally calibrating the temperature adjustment factor a d used for dew point temperature (T dew) computation from mean temperature, ETo estimations shown small bias and small RMSE ranging from 0.15 to 0.53 mm day-1. When R s data are missing, their estimation from the temperature difference (T max-T min), using a locally and seasonal calibrated radiation adjustment coefficient (k Rs), yielded highly accurate ETo estimates, with RMSE averaging 0.41 mm day-1 and ranging from 0.33 to 0.58 mm day-1. If wind speed observations are missing, the use of the default u 2 = 2 m s-1, or 3 m s-1 in case of weather measurements over clipped grass in airports, revealed appropriated even for the windy locations (u 2 > 4 m s-1), with RMSE < 0.36 mm day-1. The appropriateness of procedure to estimating the missing values of e a, R s, and u 2 was confirmed.

Eta Carinae and Other Luminous Blue Variables

NASA Technical Reports Server (NTRS)

Corcoran, M. F.

2006-01-01

Luminous Blue Variables (LBVs) are believed to be evolved, extremely massive stars close to the Eddington Limit and hence prone to bouts of large-scale, unstable mass loss. I discuss current understanding of the evolutionary state of these objects, the role duplicity may play and known physical characteristics of these stars using the X-ray luminous LBVs Eta Carinae and HD 5980 as test cases.

Observation of {eta}{sup '} Decays to {pi}{sup +}{pi}{sup -}{pi}{sup 0} and {pi}{sup +}{pi}{sup -}e{sup +}e{sup -}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naik, P.; Rademacker, J.; Asner, D. M.

Using {psi}(2S){yields}{pi}{sup +}{pi}{sup -}J/{psi}, J/{psi}{yields}{gamma}{eta}{sup '} events acquired with the CLEO-c detector at the CESR e{sup +}e{sup -} collider, we make the first observations of the decays {eta}{sup '}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup 0} and {eta}{sup '}{yields}{pi}{sup +}{pi}{sup -}e{sup +}e{sup -}, measuring absolute branching fractions (37{sub -9}{sup +11}{+-}4)x10{sup -4} and (25{sub -9}{sup +12}{+-}5)x10{sup -4}, respectively. For {eta}{sup '}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup 0}, this result probes the mechanism of isospin violation and the roles of {pi}{sup 0}/{eta}/{eta}{sup '}-mixing and final state rescattering in strong decays. We also set upper limits on branching fractions for {eta}{sup '} decays to {pi}{sup +}{pi}{sup -}{mu}{sup +}{mu}{sup -}, 2({pi}{supmore » +}{pi}{sup -}), {pi}{sup +}{pi}{sup -}2{pi}{sup 0}, 2({pi}{sup +}{pi}{sup -}){pi}{sup 0}, 3({pi}{sup +}{pi}{sup -}), and invisible final states.« less

Selective endothelin ETA and dual ET(A)/ET(B) receptor blockade improve endothelium-dependent vasodilatation in patients with type 2 diabetes and coronary artery disease.

PubMed

Rafnsson, Arnar; Shemyakin, Alexey; Pernow, John

2014-11-24

Endothelin-1 contributes to endothelial dysfunction in patients with atherosclerosis and type 2 diabetes. In healthy arteries the ETA receptor mediates the main part of the vasoconstriction induced by endothelin-1 whilst the ETB receptor mediates vasodilatation. The ETB receptor expression is upregulated on vascular smooth muscle cells in atherosclerosis and may contribute to the increased vasoconstrictor tone and endothelial dysfunction observed in this condition. Due to these opposing effects of the ETB receptor it remains unclear whether ETB blockade together with ETA blockade may be detrimental or beneficial. The aim was therefore to compare the effects of selective ETA and dual ETA/ETB blockade on endothelial function in patients with type 2 diabetes and coronary artery disease. Forearm endothelium-dependent and endothelium-independent vasodilatation was assessed by venous occlusion plethysmography in 12 patients before and after selective ETA or dual ETA/ETB receptor blockade. Dual ETA/ETB receptor blockade increased baseline forearm blood flow by 30±14% (P<0.01) whereas selective ETA blockade did not (14±8%). Both selective ETA blockade and dual ETA/ETB blockade significantly improved endothelium-dependent vasodilatation. The improvement did not differ between the two treatments. There was also an increase in endothelium-independent vasodilatation with both treatments. Dual ETA/ETB blockade did not significantly increase microvascular flow but improved transcutaneous pO2. Both selective ETA and dual ETA/ETB improve endothelium-dependent vasodilatation in patients with type 2 diabetes and coronary artery disease. ETB blockade increases basal blood flow but does not additionally improve endothelium-dependent vasodilatation. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

4-D Imaging and Modeling of Eta Carinae's Inner Fossil Wind Structures

NASA Astrophysics Data System (ADS)

Madura, Thomas I.; Gull, Theodore; Teodoro, Mairan; Clementel, Nicola; Corcoran, Michael; Damineli, Augusto; Groh, Jose; Hamaguchi, Kenji; Hillier, D. John; Moffat, Anthony; Richardson, Noel; Weigelt, Gerd; Lindler, Don; Feggans, Keith

2017-11-01

Eta Carinae is the most massive active binary within 10,000 light-years and is famous for the largest non-terminal stellar explosion ever recorded. Observations reveal that the supermassive (~120 M⊙) binary, consisting of an LBV and either a WR or extreme O star, undergoes dramatic changes every 5.54 years due to the stars' very eccentric orbits (e ~ 0.9). Many of these changes are caused by a dynamic wind-wind collision region (WWCR) between the stars, plus expanding fossil WWCRs formed one, two, and three 5.54-year cycles ago. The fossil WWCRs can be spatially and spectrally resolved by the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). Starting in June 2009, we used the HST/STIS to spatially map Eta Carinae's fossil WWCRs across one full orbit, following temporal changes in several forbidden emission lines (e.g. [Feiii] 4659 Å, [Feii] 4815 Å), creating detailed data cubes at multiple epochs. Multiple wind structures were imaged, revealing details about the binary's orbital motion, photoionization properties, and recent (~5 - 15 year) mass-loss history. These observations allow us to test 3-D hydrodynamical and radiative-transfer models of the interacting winds. Our observations and models strongly suggest that the wind and photoionization properties of Eta Carinae's binary have not changed substantially over the past several orbital cycles. They also provide a baseline for following future changes in Eta Carinae, essential for understanding the late-stage evolution of this nearby supernova progenitor. For more details, see Gull et al. (2016) and references therein.

TDR Technique for Estimating the Intensity of Evapotranspiration of Turfgrasses.

PubMed

Janik, Grzegorz; Wolski, Karol; Daniel, Anna; Albert, Małgorzata; Skierucha, Wojciech; Wilczek, Andrzej; Szyszkowski, Paweł; Walczak, Amadeusz

2015-01-01

The paper presents a method for precise estimation of evapotranspiration of selected turfgrass species. The evapotranspiration functions, whose domains are only two relatively easy to measure parameters, were developed separately for each of the grass species. Those parameters are the temperature and the volumetric moisture of soil at the depth of 2.5 cm. Evapotranspiration has the character of a modified logistic function with empirical parameters. It assumes the form ETR(θ (2.5 cm), T (2.5 cm)) = A/(1 + B · e (-C · (θ (2.5 cm) · T (2.5 cm)), where: ETR(θ (2.5 cm), T (2.5 cm)) is evapotranspiration [mm · h(-1)], θ (2.5 cm) is volumetric moisture of soil at the depth of 2.5 cm [m(3) · m(-3)], T (2.5 cm) is soil temperature at the depth of 2.5 cm [°C], and A, B, and C are empirical coefficients calculated individually for each of the grass species [mm · h(1)], and [-], [(m(3) · m(-3) · °C)(-1)]. The values of evapotranspiration calculated on the basis of the presented function can be used as input data for the design of systems for the automatic control of irrigation systems ensuring optimum moisture conditions in the active layer of lawn swards.

Urban heat island-induced increases in evapotranspirative demand

NASA Astrophysics Data System (ADS)

Zipper, Samuel C.; Schatz, Jason; Kucharik, Christopher J.; Loheide, Steven P.

2017-01-01

Although the importance of vegetation in mitigating the urban heat island (UHI) is known, the impacts of UHI-induced changes in micrometeorological conditions on vegetation are not well understood. Here we show that plant water requirements are significantly higher in urban areas compared to rural areas surrounding Madison, WI, driven by increased air temperature with minimal effects of decreased air moisture content. Local increases in impervious cover are strongly associated with increased evapotranspirative demand in a consistent manner across years, with most increases caused by elevated temperatures during the growing season rather than changes in changes in growing season length. Potential evapotranspiration is up to 10% higher due to the UHI, potentially mitigating changes to the water and energy balances caused by urbanization. Our results indicate that local-scale land cover decisions (increases in impervious cover) can significantly impact evapotranspirative demand, with likely implications for water and carbon cycling in urban ecosystems.

Non-discharging evapotranspiration bed system for wastewater disposal at Lincoln.

PubMed

Balley, P; Dakers, A J

1996-10-01

A non-discharging evapotranspiration bed system installed on a dairy farm at Lincoln University was studied to evaluate actual evapotranspiration rate, ET a , to develop and validate a water balance model for the system, and to assess the feasible application of the vaporative concept for wastewater disposal in the immediate geographic area. Observations, measurements, and calculations indicate that ET a was slightly higher than the meteorologically estimated Penman potential ET (ET p ) for the study period, and a ratio λ=ET a /ET p =1.21 was obtained. A water-balance equation of the system which can be used in different climatic conditions was obtained and can be written as ΔW=Q+PPTN-Et a ; where ΔW is the variation of storage water in the bed (in mm), Q is the effluent wastewater (in mm), and PPTN is the total precipitation. It was also observed that a truly non-discharging ET bed system's feasible application in the study location may be highly questionable. This is due to the fact that the precipitation rate for the location generally exceeds the ET p during critical Winter months. However, two possibilities of improving the performance of the system were found and suggested for further studies. The suggestions were (1) to design the system with its surface adequately crowned to shed large amounts of rain water falling on it, and (2) to design a winter-sheltered-non-discharging ET bed which would consist of an ET bed with a removable transparent plastic roof to shed the total amount of rain water and act as a 'green house'

Decline of the 2-10 keV Emission from Eta Carinae

NASA Technical Reports Server (NTRS)

Liburd, Jamar; Corcoran, Michael F.; Hamaguchi, Kenji; Gull, Theodore R.; Madura, Thomas; Teodoro, Mairan; Moffat, Anthony; Richardson, Noel; Russell, Chris; Pollock, Andrew;

Acyclic High-Energy Variability in Eta Carinae and WR 140

NASA Technical Reports Server (NTRS)

Corcoran, Michael F.

2012-01-01

Eta Carinae and WR 140 are similar long-period colliding wind binaries in which X-ray emission is produced by a strong shock due to the collision of the powerful stellar winds. The change in the orientation and density of this shock as the stars revolve in their orbits influences the X-ray flux and spectrum in a phase dependent way. Monitoring observations with RXTE and other X-ray satellite observatories since the 1990s have detailed this variability but have also shown significant deviations from strict phase dependence (short-term brightness changes or "flares", and cyc1e-to-cyc1e average flux differences). We examine these acylic variations in Eta Car and WR 140 and discuss what they tell us about the stability of the wind-wind collision shock.

Effects of climate change on evapotranspiration over the Okavango Delta water resources

NASA Astrophysics Data System (ADS)

Moses, Oliver; Hambira, Wame L.

2018-06-01

In semi-arid developing countries, most poor people depend on contaminated surface or groundwater resources since they do not have access to safe and centrally supplied water. These water resources are threatened by several factors that include high evapotranspiration rates. In the Okavango Delta region in the north-western Botswana, communities facing insufficient centrally supplied water rely mainly on the surface water resources of the Delta. The Delta loses about 98% of its water through evapotranspiration. However, the 2% remaining water rescues the communities facing insufficient water from the main stream water supply. To understand the effects of climate change on evapotranspiration over the Okavango Delta water resources, this study analysed trends in the main climatic parameters needed as input variables in evapotranspiration models. The Mann Kendall test was used in the analysis. Trend analysis is crucial since it reveals the direction of trends in the climatic parameters, which is helpful in determining the effects of climate change on evapotranspiration. The main climatic parameters required as input variables in evapotranspiration models that were of interest in this study were wind speeds, solar radiation and relative humidity. Very little research has been conducted on these climatic parameters in the Okavango Delta region. The conducted trend analysis was more on wind speeds, which had relatively longer data records than the other two climatic parameters of interest. Generally, statistically significant increasing trends have been found, which suggests that climate change is likely to further increase evapotranspiration over the Okavango Delta water resources.

Stable isotope measurements of evapotranspiration partitioning in a maize field

NASA Astrophysics Data System (ADS)

Hogan, Patrick; Parajka, Juraj; Oismüller, Markus; Strauss, Peter; Heng, Lee; Blöschl, Günter

2017-04-01

Evapotranspiration (ET) is one of the most important processes in describing land surface - atmosphere interactions as it connects the energy and water balances. Furthermore knowledge of the individual components of evapotranspiration is important for ecohydrological modelling and agriculture, particularly for irrigation efficiency and crop productivity. In this study, we tested the application of the stable isotope method for evapotranspiration partitioning to a maize crop during the vegetative stage, using sap flow sensors as a comparison technique. Field scale ET was measured using an eddy covariance device and then partitioned using high frequency in-situ measurements of the isotopic signal of the canopy water vapor. The fraction of transpiration (Ft) calculated with the stable isotope method showed good agreement with the sap flow method. High correlation coefficient values were found between the two techniques, indicating the stable isotope method can successfully be applied in maize. The results show the changes in transpiration as a fraction of evapotranspiration after rain events and during the subsequent drying conditions as well as the relationship between transpiration and solar radiation and vapor pressure deficit.

31 CFR 208.5 - Availability of the ETA SM.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Availability of the ETA SM. 208.5 Section 208.5 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE MANAGEMENT OF FEDERAL AGENCY...

Methods to estimate irrigated reference crop evapotranspiration - a review.

PubMed

Kumar, R; Jat, M K; Shankar, V

2012-01-01

Efficient water management of crops requires accurate irrigation scheduling which, in turn, requires the accurate measurement of crop water requirement. Irrigation is applied to replenish depleted moisture for optimum plant growth. Reference evapotranspiration plays an important role for the determination of water requirements for crops and irrigation scheduling. Various models/approaches varying from empirical to physically base distributed are available for the estimation of reference evapotranspiration. Mathematical models are useful tools to estimate the evapotranspiration and water requirement of crops, which is essential information required to design or choose best water management practices. In this paper the most commonly used models/approaches, which are suitable for the estimation of daily water requirement for agricultural crops grown in different agro-climatic regions, are reviewed. Further, an effort has been made to compare the accuracy of various widely used methods under different climatic conditions.

Hubble Space Telescope imaging of Eta Carinae

NASA Technical Reports Server (NTRS)

Hester, J. J.; Westphal, James A.; Light, Robert M.; Currie, Douglas G.; Groth, Edward J.

1991-01-01

New high spatial resolution observations of the material around Eta Carinae, obtained with the Hubble Space Telescope Wide Field/Planetary Camera, are presented. The star Eta Carinae is one of the most massive and luminous stars in the Galaxy, and has been episodically expelling significant quantities of gas over the last few centuries. The morphology of the bright central nebulosity (the homunculus) indicates that it is a thin shell with very well defined edges, and is clumpy on 0.2 arcsec (about 10 to the 16th cm) scales. An extension to the northeast of the star (NN/NS using Walborn's 1976 nomenclature) appears to be a stellar jet and its associated bow shock. The bow shock is notable for an intriguing series of parallel linear features across its face. The S ridge and the W arc appear to be part of a 'cap' of emission located to the SW and behind the star. Together, the NE jet and the SW cap suggest that the symmetry axis for the system runs NE-SW rather than SE-NW, as previously supposed. Overall, the data indicate that the material around the star may represent an oblate shell with polar blowouts, rather than a bipolar flow.

Massive stars near Eta Carinae - The stellar content of TR 14 and TR 16

NASA Astrophysics Data System (ADS)

Massey, Philip; Johnson, Jennifer

1993-03-01

The stellar content of the region around the star Eta Carinae, including the two Galactic OB clusters Tr 14 and Tr 16, are investigated using CCD photometry and spectroscopy. A physical H-R diagram is constructed which shows that several stars are located above the 85-solar mass track, as well as that the location of Eta Carinae is consistent with the interpretation that it is a very massive star undergoing a normal evolutionary stage. The W-R star which is present in this region is lower in luminosity than expected. The initial mass function derived, which is similar to two other young Galactic clusters studied, has a slope flatter than some regions in the Magellanic Clouds that are also rich in massive stars. The most luminous and massive stars near Eta Carinae are not significantly more than the most luminous and massive stars found in the Magellanic Clouds.

Brightness Variations in the Central Star of Eta Carinae From 1998 to the Present

NASA Technical Reports Server (NTRS)

Martin, J. C.; Koppelman, M. D.

2004-01-01

Recently, Eta Carinae has varied suprisingly in brightness combining a long term brightening trend with a 5.5-year cycle and unpredictable sporadic jumps. Only the Hubble Space Telescope had been able to provide reliable photometry of the central star resolved separately from its bright ejecta. We present data from the Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) and the Advanced Camera for Surveys High Resolution Camera (ACS/HRC) which chronicle the dramatic brightening of the central star of Eta Carinae from the 1998 "event" through 2000 and show that is has continued to slowly brighten. More frequent photometry during its recent "event" and a continued rise afterward. These data are compared to the more long term data compiled by the American Association of Variable Star Observers (AAVSO) which also shows substantial brightening between events and other intervening fluctuations in the brightness of Eta Carinae at visual wavelengths.

A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nefkens, B M; Prakhov, S; Aguar-Bartolom��, P

2014-08-01

A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> etamore » p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence.« less

Branching Fraction Measurements of the Color-Suppressed Decays B0bar to D(*)0 pi0, D(*)0 eta, D(*)0 omega, and D(*)0 eta_prime and Measurement of the Polarization in the Decay B0bar to D*0 omega

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lees, J.P.; Poireau, V.; Tisserand, V.

2012-02-14

We report updated branching fraction measurements of the color-suppressed decays {bar B}{sup 0} {yields} D{sup 0}{pi}{sup 0}, D*{sup 0}{pi}{sup 0}, D{sup 0}{eta}, D*{sup 0}{eta}, D{sup 0}{omega}, D*{sup 0}{omega}, D{sup 0}{eta}', and D*{sup 0}{eta}'. We measure the branching fractions (x10{sup -4}): {Beta}({bar B}{sup 0} {yields} D{sup 0}{pi}{sup 0}) = 2.69 {+-} 0.09 {+-} 0.13, {Beta}({bar B}{sup 0} {yields} D*{sup 0}{pi}{sup 0}) = 3.05 {+-} 0.14 {+-} 0.28, {Beta}({bar B}{sup 0} {yields} D{sup 0}{eta}) = 2.53 {+-} 0.09 {+-} 0.11, {Beta}({bar B}{sup 0} {yields} D*{sup 0}{eta}) = 2.69 {+-} 0.14 {+-} 0.23, {Beta}({bar B}{sup 0} {yields} D{sup 0}{omega}) = 2.57 {+-} 0.11more » {+-} 0.14, {Beta}({bar B}{sup 0} {yields} D*{sup 0}{omega}) = 4.55 {+-} 0.24 {+-} 0.39, {Beta}({bar B}{sup 0} {yields} D{sup 0}{eta}') = 1.48 {+-} 0.13 {+-} 0.07, and {Beta}({bar B}{sup 0} {yields} D*{sup 0}{eta}') = 1.49 {+-} 0.22 {+-} 0.15. We also present the first measurement of the longitudinal polarization fraction of the decay channel D*{sup 0}{omega}, f{sub L} = (66.5 {+-} 4.7 {+-} 1.5)%. In the above, the first uncertainty is statistical and the second is systematic. The results are based on a sample of (454 {+-} 5) x 10{sup 6} B{bar B} pairs collected at the {Upsilon}(4S) resonance, with the BABAR detector at the PEP-II storage rings at SLAC. The measurements are the most precise determinations of these quantities from a single experiment. They are compared to theoretical predictions obtained by factorization, Soft Collinear Effective Theory (SCET) and perturbative QCD (pQCD). We find that the presence of final state interactions is favored and the measurements are in better agreement with SCET than with pQCD.« less

TDR Technique for Estimating the Intensity of Evapotranspiration of Turfgrasses

PubMed Central

Janik, Grzegorz; Wolski, Karol; Daniel, Anna; Albert, Małgorzata; Wilczek, Andrzej; Szyszkowski, Paweł; Walczak, Amadeusz

2015-01-01

The paper presents a method for precise estimation of evapotranspiration of selected turfgrass species. The evapotranspiration functions, whose domains are only two relatively easy to measure parameters, were developed separately for each of the grass species. Those parameters are the temperature and the volumetric moisture of soil at the depth of 2.5 cm. Evapotranspiration has the character of a modified logistic function with empirical parameters. It assumes the form ETR(θ 2.5 cm, T 2.5 cm) = A/(1 + B · e −C·(θ2.5 cm · T2.5 cm)), where: ETR(θ 2.5 cm, T 2.5 cm) is evapotranspiration [mm·h−1], θ 2.5 cm is volumetric moisture of soil at the depth of 2.5 cm [m3·m−3], T 2.5 cm is soil temperature at the depth of 2.5 cm [°C], and A, B, and C are empirical coefficients calculated individually for each of the grass species [mm·h1], and [—], [(m3·m−3·°C)−1]. The values of evapotranspiration calculated on the basis of the presented function can be used as input data for the design of systems for the automatic control of irrigation systems ensuring optimum moisture conditions in the active layer of lawn swards. PMID:26448964

Assessing reference evapotranspiration in a subhumid climate in NE Austria

NASA Astrophysics Data System (ADS)

Nolz, Reinhard; Eitzinger, Josef; Cepuder, Peter

2015-04-01

Computing reference evapotranspiration and multiplying it with a specific crop coefficient as recommended by the Food and Agriculture Organization of the United Nations (FAO) is the most widely accepted approach to estimate plant water requirements. The standardized form of the well-known FAO Penman-Monteith equation, published by the Environmental and Water Resources Institute of the American Society of Civil Engineers (ASCE-EWRI), is recommended as a standard procedure for calculating reference evapotranspiration. Applied and validated under different climatic conditions it generally achieved good results compared to other methods. However, several studies documented deviations between measured and calculated reference evapotranspiration depending on local environmental conditions. Consequently, it seems advisable to evaluate the model under local environmental conditions. Evapotranspiration was determined at a subhumid site in Austria (48°12'N, 16°34'E; 157 m asl) using a large weighing lysimeter operated at (limited) reference conditions and compared with calculations according to ASCE-EWRI. The lysimeter had an inner diameter of 1.9 m and a hemispherical bottom with a maximum depth of 2.5 m. Seepage water was measured at a free draining outlet using a tipping bucket. Lysimeter mass changes were sensed by a weighing facility with an accuracy of ±0.1 mm. Both rainfall and evapotranspiration were determined directly from lysimeter data using a simple water balance equation. Meteorological data for the ASCE-EWRI model were obtained from a weather station of the Central Institute for Meteorology and Geodynamics, Austria (ZAMG). The study period was from 2005 to 2010, analyses were based upon daily time steps. Daily calculated reference evapotranspiration was generally overestimated at small values, whereas it was rather underestimated when evapotranspiration was large, which is supported also by other studies. In the given case, advection of sensible heat proved

Evapotranspiration information reporting: II. Recommended documentation

USDA-ARS?s Scientific Manuscript database

Researchers and journal authors, reviewers, and readers can benefit from more complete documentation of published evapotranspiration (ET) information, including a description of field procedures, instrumentation, data filtering, model parameterization, and site review. This information is important ...

Remote Sensing of Snow and Evapotranspiration

NASA Technical Reports Server (NTRS)

Schmugge, T. (Editor)

1985-01-01

The use of snowmelt runoff models from both the U.S. and Japan for simulating discharge on basins in both countries is discussed as well as research in snowpack properties and evapotranspiration using remotely sensed data.

77 FR 37713 - Comment Request for Information Collection for ETA 9162, Random Audit of EUC 2008 Claimants...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-22

... Collection for ETA 9162, Random Audit of EUC 2008 Claimants, Comment Request for Extension Without Change... assessed. Currently, ETA is soliciting comments concerning the collection of data about Random Audit of... describing random audits of the work search provision of Public Law 112-96 (see Section 2141(b)). Random...

The steady-state level and stability of TLS polymerase eta are cell cycle dependent in the yeast S. cerevisiae.

PubMed

Plachta, Michal; Halas, Agnieszka; McIntyre, Justyna; Sledziewska-Gojska, Ewa

2015-05-01

Polymerase eta (Pol eta) is a ubiquitous translesion DNA polymerase that is capable of bypassing UV-induced pyrimidine dimers in an error-free manner. However, this specialized polymerase is error prone when synthesizing through an undamaged DNA template. In Saccharomyces cerevisiae, both depletion and overproduction of Pol eta result in mutator phenotypes. Therefore, regulation of the cellular abundance of this enzyme is of particular interest. However, based on the investigation of variously tagged forms of Pol eta, mutually contradictory conclusions have been reached regarding the stability of this polymerase in yeast. Here, we optimized a protocol for the detection of untagged yeast Pol eta and established that the half-life of the native enzyme is 80 ± 14 min in asynchronously growing cultures. Experiments with synchronized cells indicated that the cellular abundance of this translesion polymerase changes throughout the cell cycle. Accordingly, we show that the stability of Pol eta, but not its mRNA level, is cell cycle stage dependent. The half-life of the polymerase is more than fourfold shorter in G1-arrested cells than in those at G2/M. Our results, in concert with previous data for Rev1, indicate that cell cycle regulation is a general property of Y family TLS polymerases in S. cerevisiae. Copyright © 2015 Elsevier B.V. All rights reserved.

Evapotranspiration response to multi-year dry periods in the semi-arid western United States

NASA Astrophysics Data System (ADS)

Rungee, J. P., II; Bales, R. C.

2017-12-01

Analysis of measured evapotranspiration shows multi-year regolith water storage can support evapotranspiration for years into a multi-year dry period. Measurements at 25 flux-tower sites in the semi-arid western United States, distributed across five primary land-cover types, show both resilience and vulnerability to multi-year dry periods. Average evapotranspiration ranged from about 700+200 mm per water year (October-September) in evergreen needleleaf forests to 350+150 mm per water year in grasslands and open shrublands. On average, in California's Mediterranean climate almost half of the water-year evapotranspiration is supported by seasonal and/or multi-year regolith water storage, compared to a characteristic 20 to 30 percent value of energy-limited and inland sites. Below 35oN latitude, water-year evapotranspiration exceeded estimated precipitation in over half of the years on record. For non-energy-limited sites, water-year evapotranspiration increased with precipitation up to a maximum water-year evapotranspiration value of about 900, 750, 600, 425 and 300 mm per water year for evergreen needleleaf forests, mixed forests, woody savannas, grasslands and open shrublands, respectively. There were 15 multi-year dry periods on record that exhibited either an attenuation in evapotranspiration, defined as an annual value below 80% of the wet-year average, or withdrawal from multi-year storage. A multi-year dry period was defined as three or more consecutive water years in which all water-year precipitation values and the mean period value were in the lower 50 and 35 percent of the historical record, respectively. For sites exhibiting evapotranspiration attenuation, resistance to multi-year dry periods ranged from 9 to 49 months, drafting as much as 444 mm of regolith storage. At some mountain sites regolith storage provided up to 678 mm, almost the equivalent of the average water-year evapotranspiration for these sites, over the extent of the multi-year dry

RIP-ET: A riparian evapotranspiration package for MODFLOW-2005

USGS Publications Warehouse

Maddock, Thomas; Baird, Kathryn J.; Hanson, R.T.; Schmid, Wolfgang; Ajami, Hoori

2012-01-01

A new evapotranspiration package for the U.S. Geological Survey's groundwater-flow model, MODFLOW, is documented. The Riparian Evapotranspiration Package (RIP-ET) provides flexibility in simulating riparian and wetland transpiration not provided by the Evapotranspiration (EVT) or Segmented Function Evapotranspiration (ETS1) Packages for MODFLOW 2005. This report describes how the RIP-ET package was conceptualized and provides input instructions, listings and explanations of the source code, and an example. Traditional approaches to modeling evapotranspiration (ET) processes assume a piecewise linear relationship between ET flux and hydraulic head. The RIP-ET replaces this traditional relationship with a segmented, nonlinear dimensionless curve that reflects the eco-physiology of riparian and wetland ecosystems. Evapotranspiration losses from these ecosystems are dependent not only on hydraulic head, but on the plant types present. User-defined plant functional groups (PFGs) are used to elucidate the interaction between plant transpiration and groundwater conditions. Five generalized plant functional groups based on transpiration rates, plant rooting depth, and water tolerance ranges are presented: obligate wetland, shallow-rooted riparian, deep-rooted riparian, transitional riparian and bare ground/open water. Plant functional groups can be further divided into subgroups (PFSGs) based on plant size, density or other characteristics. The RIP-ET allows for partial habitat coverage and mixtures of plant functional subgroups to be present in a single model cell. RIP-ET also distinguishes between plant transpiration and bare-ground evaporation. Habitat areas are designated by polygons; each polygon can contain a mixture of PFSGs and bare ground, and is assigned a surface elevation. This process requires a determination of fractional coverage for each of the plant functional subgroups present in a polygon to account for the mixture of coverage types and resulting

Eta Lyrids (ELY-145)

NASA Astrophysics Data System (ADS)

Roggemans, Paul; Cambell-Burns, Peter

2018-03-01

Two years in a row the eta Lyrids (#145-ELY) caught the attention of the CAMS BeNeLux camera network with surprisingly large numbers of orbits collected for this stream. An independent search was made on the data of 686000 public available video meteor orbits. The results confirm earlier studies with a clear activity profile between solar longitude 45° and 53° with a sharp peak at 49.5±0.2°. No mention of this shower could be found before the passage of the parent comet C/1983 H1 (IRAS-Araki-Alcock) in 1983. In recent years the shower tends to surprise observers with some low but distinct activity. Outbursts are not excluded in the future, observers are recommended to keep an eye on this shower.

Rainfall and evapotranspiration data for southwest Medina County, Texas, August 2006-December 2009

USGS Publications Warehouse

Slattery, Richard N.; Asquith, William H.; Ockerman, Darwin J.

2011-01-01

During August 2006-December 2009, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers, Fort Worth District, collected rainfall and evapotranspiration data to help characterize the hydrology of the Nueces River Basin, Texas. The USGS installed and operated a station to collect continuous (30-minute interval) rainfall and evapotranspiration data in southwest Medina County approximately 14 miles southwest of D'Hanis, Texas, and 23 miles northwest of Pearsall, Texas. Rainfall data were collected by using an 8-inch tipping bucket raingage. Meteorological and surface-energy flux data used to calculate evapotranspiration were collected by using an extended Open Path Eddy Covariance system from Campbell Scientific, Inc. Data recorded by the system were used to calculate evapotranspiration by using the eddy covariance and Bowen ratio closure methods and to analyze the surface energy budget closure. During August 2006-December 2009 (excluding days of missing record), measured rainfall totaled 86.85 inches. In 2007, 2008, and 2009, annual rainfall totaled 40.98, 12.35, and 27.15 inches, respectively. The largest monthly rainfall total, 12.30 inches, occurred in July 2007. During August 2006-December 2009, evapotranspiration calculated by using the eddy covariance method totaled 69.91 inches. Annual evapotranspiration calculated by using the eddy covariance method totaled 34.62 inches in 2007, 15.24 inches in 2008, and 15.57 inches in 2009. During August 2006-December 2009, evapotranspiration calculated by using the Bowen ratio closure method (the more refined of the two datasets) totaled 68.33 inches. Annual evapotranspiration calculated by using the Bowen ratio closure method totaled 32.49, 15.54, and 15.80 inches in 2007, 2008, and 2009, respectively (excluding days of missing record).

Progress in ETA-II magnetic field alignment using stretched wire and low energy electron beam techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deadrick, F.J.; Griffith, L.V.

1990-08-17

Flux line alignment of the solenoidal focus magnets used on the ETA-II linear induction accelerator is a key element leading to a reduction of beam corkscrew motion. Two techniques have been used on the ETA-II accelerator to measure and establish magnet alignment. A low energy electron beam has been used to directly map magnetic field lines, and recent work has utilized a pulsed stretched wire technique to measure magnet tilts and offsets with respect to a reference axis. This paper reports on the techniques used in the ETA-II accelerator alignment, and presents results from those measurements which show that acceleratormore » is magnetically aligned to within {approximately}{plus minus}200 microns. 3 refs., 8 figs.« less

Assessment of Evapotranspiration and Soil Moisture Content Across Different Scales of Observation

PubMed Central

Verstraeten, Willem W.; Veroustraete, Frank; Feyen, Jan

2008-01-01

The proper assessment of evapotranspiration and soil moisture content are fundamental in food security research, land management, pollution detection, nutrient flows, (wild-) fire detection, (desert) locust, carbon balance as well as hydrological modelling; etc. This paper takes an extensive, though not exhaustive sample of international scientific literature to discuss different approaches to estimate land surface and ecosystem related evapotranspiration and soil moisture content. This review presents: (i)a summary of the generally accepted cohesion theory of plant water uptake and transport including a shortlist of meteorological and plant factors influencing plant transpiration;(ii)a summary on evapotranspiration assessment at different scales of observation (sap-flow, porometer, lysimeter, field and catchment water balance, Bowen ratio, scintillometer, eddy correlation, Penman-Monteith and related approaches);(iii)a summary on data assimilation schemes conceived to estimate evapotranspiration using optical and thermal remote sensing; and(iv)for soil moisture content, a summary on soil moisture retrieval techniques at different spatial and temporal scales is presented. Concluding remarks on the best available approaches to assess evapotranspiration and soil moisture content with and emphasis on remote sensing data assimilation, are provided. PMID:27879697

Analytical solutions of travel time to a pumping well with variable evapotranspiration.

PubMed

Chen, Tian-Fei; Wang, Xu-Sheng; Wan, Li; Li, Hailong

2014-01-01

Analytical solutions of groundwater travel time to a pumping well in an unconfined aquifer have been developed in previous studies, however, the change in evapotranspiration was not considered. Here, we develop a mathematical model of unconfined flow toward a discharge well with redistribution of groundwater evapotranspiration for travel time analysis. Dependency of groundwater evapotranspiration on the depth to water table is described using a linear formula with an extinction depth. Analytical solutions of groundwater level and travel time are obtained. For a typical hypothetical example, these solutions perfectly agree with the numerical simulation results based on MODFLOW and MODPATH. As indicated in a dimensionless framework, a lumped parameter which is proportional to the pumping rate controls the distributions of groundwater evapotranspiration rate and the travel time along the radial direction. © 2013, National Ground Water Association.

Upregulation of 14-3-3 eta in chronic liver fluke infection is a potential diagnostic marker of cholangiocarcinoma.

PubMed

Haonon, Ornuma; Rucksaken, Rucksak; Pinlaor, Porntip; Pairojkul, Chawalit; Chamgramol, Yaovalux; Intuyod, Kitti; Onsurathum, Sudarat; Khuntikeo, Narong; Pinlaor, Somchai

2016-03-01

To discover protein markers in chronic/advanced opisthorchiasis for the early detection of Opisthorchis viverrini (OV)-associated cholangiocarcinoma (CCA). Liver tissues derived from normal hamsters and those with chronic/advanced opisthorchiasis (n = 5 per group) were subjected to 2DE and LC-MS/MS. Candidate protein expression was confirmed in hamster models and human CCA tissue microarray (TMA) using immunohistochemistry and Western blot. Proteomics analysis detected 14-3-3 eta only in infected hamsters, not in uninfected controls. Immunohistochemistry and Western blot analysis confirmed low expression of 14-3-3 eta in normal hamster livers and demonstrated increased expression through time in infected livers. This protein was also observed in parasite organs, especially during the chronic phase of opisthorchiasis. Moreover, increased expression of 14-3-3 eta, relative to normal hamster livers, was observed during the early stage of CCA induced by OV infection and administration of N-nitrosodimethylamine. Immunohistochemical analysis of human TMA revealed that 14-3-3 eta was highly expressed in CCA (84.23%, 187/222 cases) but was not found in hepatocellular carcinoma or healthy liver tissues. 14-3-3 eta protein has potential as a screening and early diagnostic marker for CCA. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Estimating wheat and maize daily evapotranspiration using artificial neural network

NASA Astrophysics Data System (ADS)

Abrishami, Nazanin; Sepaskhah, Ali Reza; Shahrokhnia, Mohammad Hossein

2018-02-01

In this research, artificial neural network (ANN) is used for estimating wheat and maize daily standard evapotranspiration. Ten ANN models with different structures were designed for each crop. Daily climatic data [maximum temperature (T max), minimum temperature (T min), average temperature (T ave), maximum relative humidity (RHmax), minimum relative humidity (RHmin), average relative humidity (RHave), wind speed (U 2), sunshine hours (n), net radiation (Rn)], leaf area index (LAI), and plant height (h) were used as inputs. For five structures of ten, the evapotranspiration (ETC) values calculated by ETC = ET0 × K C equation (ET0 from Penman-Monteith equation and K C from FAO-56, ANNC) were used as outputs, and for the other five structures, the ETC values measured by weighing lysimeter (ANNM) were used as outputs. In all structures, a feed forward multiple-layer network with one or two hidden layers and sigmoid transfer function and BR or LM training algorithm was used. Favorite network was selected based on various statistical criteria. The results showed the suitable capability and acceptable accuracy of ANNs, particularly those having two hidden layers in their structure in estimating the daily evapotranspiration. Best model for estimation of maize daily evapotranspiration is «M»ANN1 C (8-4-2-1), with T max, T min, RHmax, RHmin, U 2, n, LAI, and h as input data and LM training rule and its statistical parameters (NRMSE, d, and R2) are 0.178, 0.980, and 0.982, respectively. Best model for estimation of wheat daily evapotranspiration is «W»ANN5 C (5-2-3-1), with T max, T min, Rn, LAI, and h as input data and LM training rule, its statistical parameters (NRMSE, d, and R 2) are 0.108, 0.987, and 0.981 respectively. In addition, if the calculated ETC used as the output of the network for both wheat and maize, higher accurate estimation was obtained. Therefore, ANN is suitable method for estimating evapotranspiration of wheat and maize.

A prototype operational earthquake loss model for California based on UCERF3-ETAS – A first look at valuation

USGS Publications Warehouse

Field, Edward; Porter, Keith; Milner, Kevn

2017-01-01

We present a prototype operational loss model based on UCERF3-ETAS, which is the third Uniform California Earthquake Rupture Forecast with an Epidemic Type Aftershock Sequence (ETAS) component. As such, UCERF3-ETAS represents the first earthquake forecast to relax fault segmentation assumptions and to include multi-fault ruptures, elastic-rebound, and spatiotemporal clustering, all of which seem important for generating realistic and useful aftershock statistics. UCERF3-ETAS is nevertheless an approximation of the system, however, so usefulness will vary and potential value needs to be ascertained in the context of each application. We examine this question with respect to statewide loss estimates, exemplifying how risk can be elevated by orders of magnitude due to triggered events following various scenario earthquakes. Two important considerations are the probability gains, relative to loss likelihoods in the absence of main shocks, and the rapid decay of gains with time. Significant uncertainties and model limitations remain, so we hope this paper will inspire similar analyses with respect to other risk metrics to help ascertain whether operationalization of UCERF3-ETAS would be worth the considerable resources required.

Evapotranspiration from a cypress and pine forest subjected to natural fires, Volusia County, Florida, 1998-99

USGS Publications Warehouse

Sumner, D.M.

2001-01-01

Daily values of evapotranspiration from a watershed in Volusia County, Florida, were estimated for a 2-year period (January 1998 through December 1999) by using an energy-budget variant of the eddy correlation method and a Priestley-Taylor model. The watershed consisted primarily of pine flatwood uplands interspersed within cypress wetlands. A drought-induced fire in spring 1998 burned about 40 percent of the watershed, most of which was subsequently logged. The model reproduced the 449 measured values of evapotranspiration reasonably well (r2=0.90) over a wide range of seasonal and surface-cover conditions. Annual evapotranspiration from the watershed was estimated to be 916 millimeters (36 inches) for 1998 and 1,070 millimeters (42 inches) for 1999. Evapotranspiration declined from near potential rates in the wet conditions of January 1998 to less than 50 percent of potential evapotranspiration after the fire and at the peak of the drought in June 1998. After the drought ended in early July 1998 and water levels returned to near land-surface, evapotranspiration increased sharply; however, the evapotranspiration rate was only about 60 percent of the potential rate in the burned areas, compared to about 90 percent of the potential rate in the unburned areas. This discrepancy can be explained as a result of fire damage to vegetation. Beginning in spring 1999, evapotranspiration from burned areas increased sharply relative to unburned areas, sometimes exceeding unburned evapotranspiration by almost 100 percent. Possible explanations for the dramatic increase in evapotranspiration from burned areas could include phenological changes associated with maturation or seasonality of plants that emerged after the fire or successional changes in composition of plant community within burned areas. Variations in daily evapotranspiration are primarily the result of variations in surface cover, net radiation, photosynthetically active radiation, air temperature, and water

Electrothermal Annealing (ETA) Method to Enhance the Electrical Performance of Amorphous-Oxide-Semiconductor (AOS) Thin-Film Transistors (TFTs).

PubMed

Kim, Choong-Ki; Kim, Eungtaek; Lee, Myung Keun; Park, Jun-Young; Seol, Myeong-Lok; Bae, Hagyoul; Bang, Tewook; Jeon, Seung-Bae; Jun, Sungwoo; Park, Sang-Hee K; Choi, Kyung Cheol; Choi, Yang-Kyu

2016-09-14

An electro-thermal annealing (ETA) method, which uses an electrical pulse of less than 100 ns, was developed to improve the electrical performance of array-level amorphous-oxide-semiconductor (AOS) thin-film transistors (TFTs). The practicality of the ETA method was experimentally demonstrated with transparent amorphous In-Ga-Zn-O (a-IGZO) TFTs. The overall electrical performance metrics were boosted by the proposed method: up to 205% for the trans-conductance (gm), 158% for the linear current (Ilinear), and 206% for the subthreshold swing (SS). The performance enhancement were interpreted by X-ray photoelectron microscopy (XPS), showing a reduction of oxygen vacancies in a-IGZO after the ETA. Furthermore, by virtue of the extremely short operation time (80 ns) of ETA, which neither provokes a delay of the mandatory TFTs operation such as addressing operation for the display refresh nor demands extra physical treatment, the semipermanent use of displays can be realized.

Evaluating ET estimates from the Simplified Surface Energy Balance (SSEB) model using METRIC model output

NASA Astrophysics Data System (ADS)

Senay, G. B.; Budde, M. E.; Allen, R. G.; Verdin, J. P.

2008-12-01

Evapotranspiration (ET) is an important component of the hydrologic budget because it expresses the exchange of mass and energy between the soil-water-vegetation system and the atmosphere. Since direct measurement of ET is difficult, various modeling methods are used to estimate actual ET (ETa). Generally, the choice of method for ET estimation depends on the objective of the study and is further limited by the availability of data and desired accuracy of the ET estimate. Operational monitoring of crop performance requires processing large data sets and a quick response time. A Simplified Surface Energy Balance (SSEB) model was developed by the U.S. Geological Survey's Famine Early Warning Systems Network to estimate irrigation water use in remote places of the world. In this study, we evaluated the performance of the SSEB model with the METRIC (Mapping Evapotranspiration at high Resolution and with Internalized Calibration) model that has been evaluated by several researchers using the Lysimeter data. The METRIC model has been proven to provide reliable ET estimates in different regions of the world. Reference ET fractions of both models (ETrF of METRIC vs. ETf of SSEB) were generated and compared using individual Landsat thermal images collected from 2000 though 2005 in Idaho, New Mexico, and California. In addition, the models were compared using monthly and seasonal total ETa estimates. The SSEB model reproduced both the spatial and temporal variability exhibited by METRIC on land surfaces, explaining up to 80 percent of the spatial variability. However, the ETa estimates over water bodies were systematically higher in the SSEB output, which could be improved by using a correction coefficient to take into account the absorption of solar energy by deeper water layers that has little contribution to the ET process. This study demonstrated the usefulness of the SSEB method for large-scale agro-hydrologic applications for operational monitoring and assessing of

Spatial and temporal variation in evapotranspiration

USDA-ARS?s Scientific Manuscript database

Spatial and temporal variation in evapotranspiration occurs at multiple scales as the result of several different spatial and temporal patterns in precipitation, soil water holding capacity, cloudiness (available energy), types of crops, and residue and tillage management practices. We have often as...

Synthesis of phospholyl-bridged heterobimetallic ruthenium hydrides in combination with zirconium and ytterbium and the crystal structure of (THF){sub 2}Yb[{mu}({eta}{sup 5}, {eta}{sup 1})-C{sub 4}Me{sub 4}P]{sub 2 }Ru(H){sub 2}(Ph{sub 3}P){sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Desmurs, P.; Visseaux, M.; Baudry, D.

1996-10-01

Heterobimetallic zirconium-ruthenium and ytterbium-ruthenium dihydrides, having bridging phospholyl ligands, have been obtained for the first time. Reaction of bis({eta}{sup 5}-tetramethylphospholyl)dichlorozirconium [(TMP){sub 2}ZrCl{sub 2}] with RuH{sub 4}(PPh{sub 3}){sub 3} gave the zirconium-ruthenium heterobimetallic Cl{sub 2}Zr[{mu}({eta}{sup 5},{eta}{sup 1})-TMP]{sub 2}Ru(H){sub 2} (PPh{sub 3}){sub 2}. This compound was transformed into the hydridochloride Cl{sub 2}Zr[{mu}({eta}{sup 5},{eta}{sup 1})-TMP]{sub 2}Ru(H)(Cl)( PPh{sub 3}){sub 2} by the action of CCl{sub 4}. Similarly, reaction of [(TMP){sub 2}Yb] with RuH{sub 4}(PPh{sub 3}){sub 3} afforded (THF){sub 2}Yb[{mu}({eta}{sup 5}, meta{sup 1})-TMP]{sub 2}Ru(H){sub 2}(PPh{sub 3}){sub 2}. The structure of this compound, which has been determined by X-ray crystallography, confirms the trans configuration of themore » dihydride deduced previously from NMR data. Attempts to isolate products from the reaction of [(TMP){sub 2}UCl{sub 2}] or [(TMP){sub 2}U(BH{sub 4}){sub 2}] with RuH{sub 4}(PPh{sub 3}){sub 3} were unsuccessful, but NMR data show the formation of both heterobimetallic trans- and cis-ruthenium dihydride-uranium compounds X{sub 2}U[{mu}({eta}{sup 5},{eta}{sup 1})-TMP]{sub 2}Ru(H){sub 2}(P Ph{sub 3}){sub 2} (X = BH{sub 4}, Cl) in solution. 19 refs., 1 fig., 2 tabs.« less

EMISSIONS PROCESSING FOR THE ETA/ CMAQ AIR QUALITY FORECAST SYSTEM

EPA Science Inventory

NOAA and EPA have created an Air Quality Forecast (AQF) system. This AQF system links an adaptation of the EPA's Community Multiscale Air Quality Model with the 12 kilometer ETA model running operationally at NOAA's National Center for Environmental Predication (NCEP). One of the...

An overview of the Central Queensland University self-contained evapotranspiration beds.

PubMed

Kele, B; Midmore, D J; Harrower, K; McKennariey, B J; Hood, B

2005-01-01

The Central Queensland University (CQU) has championed a self-contained concrete lined evapotranspiration channel. Any non-transpired effluent returns to a holding tank and is recirculated through the evapotranspiration channel until it is used. This paper examines the results from the Rockhampton trial site. Nutrient ions in the effluent were quantified over time and found not to accumulate in solution. Microbial analysis of the treated effluent was performed and was found to be within the ranges required by the relevant legislative codes. Citrus fruit grown in the evapotranspiration channel were sampled and no elevated levels of faecal coliforms were recorded. Macronutrients and micronutrients of the soil in the channels were measured over a 5-year period. No toxic accumulations or nutrient deficiencies in the soil occurred. Levels of salinity and sodicity in the evapotranspiration channel soil were quantified. Salinity rose slightly, as did sodium. Concentrations of salts and sodium did not reach unsustainable levels. The aim of the trial was to develop an on-site treatment and reuse system that is sustainable and protects public and environmental health.

Evapotranspiration from two peatland watersheds

Treesearch

Roger R. Bay

1968-01-01

Measurements of precipitation, runoff, and bog water table levels have provided data for the calculation of evapotranspiration from two forested peatland watersheds near Grand Rapids, Minnesota (ca. 47? 32'N, 93? 28'W). Continuous hydrologie records were collected on one experimental bog for 6 years (1961-1966) and on the other for the past 2 years (1965-1966...

The ``Ghost Shell'': Discovery of the Forward Shock from Colliding Winds about Eta Carinae

NASA Astrophysics Data System (ADS)

Dorland, B. N.; Currie, D. G.; Kaufer, A.; Bacciotti, F.

2003-01-01

We report on the newly discovered ``Ghost Shell'' around eta Carinae. We have detected a high-velocity ( ~ - 850 km /s), spatially extended, narrow emission feature lying in front of the southeast lobe of eta Carinae's homunculus. This feature has the speed of a high-velocity shock but the spectrum of a low-velocity shock. We propose that the Ghost Shell is the forward shock between the fast stellar wind of the great eruption of 1842 and the older, slow, massive wind. This discovery is described in more detail in Currie, Dorland, & Kaufer (2002).

Winter wheat water productivity evaluated by the developed remote sensing evapotranspiration model in Hebei Plain, China.

PubMed

Zhang, Shengwei; Zhao, Hongbin; Lei, Huimin; Shao, Hongbo; Liu, Tingxi

2015-01-01

Agricultural water is the main reason for the rapid decline of the NCP groundwater levels. It is of vital importance for the NCP sustainable agricultural development to master the ETa and its CWP. In this paper, the EBEM model was developed according to the theory of energy balance. From 2001 to 2006, the winter wheat ETa and CWP were estimated, and the spatial and temporal variations and their influencing factors were studied in the Hebei Plain. The results indicate that the EBEM model performed well by applying MODIS data to estimate the daily net radiation and ETa. For the daytime net radiation, the relative error between the estimation and the measurement amounted to 8.2% and the SEE was 0.82 MJ m(-2)/day. The average ETa deviation between the estimates and the measures amounted to 0.86 mm daily, and the SE was 1.2 mm. The spatial variations indicated that the major distribution of ETa ranged from 350 to 450 mm, which trended downward within the study area from west to east. In the study period, the winter wheat CWP was mainly distributed between 0.29 and 1.67 kg/m(3). In space, the CWP was higher in the west than in the east.

Winter Wheat Water Productivity Evaluated by the Developed Remote Sensing Evapotranspiration Model in Hebei Plain, China

PubMed Central

Zhang, Shengwei; Zhao, Hongbin; Lei, Huimin; Shao, Hongbo; Liu, Tingxi

2015-01-01

Agricultural water is the main reason for the rapid decline of the NCP groundwater levels. It is of vital importance for the NCP sustainable agricultural development to master the ETa and its CWP. In this paper, the EBEM model was developed according to the theory of energy balance. From 2001 to 2006, the winter wheat ETa and CWP were estimated, and the spatial and temporal variations and their influencing factors were studied in the Hebei Plain. The results indicate that the EBEM model performed well by applying MODIS data to estimate the daily net radiation and ETa. For the daytime net radiation, the relative error between the estimation and the measurement amounted to 8.2% and the SEE was 0.82 MJ m−2/day. The average ETa deviation between the estimates and the measures amounted to 0.86 mm daily, and the SEE was 1.2 mm. The spatial variations indicated that the major distribution of ETa ranged from 350 to 450 mm, which trended downward within the study area from west to east. In the study period, the winter wheat CWP was mainly distributed between 0.29 and 1.67 kg/m3. In space, the CWP was higher in the west than in the east. PMID:25642451

Ecological restoration of groundwater-dependent vegetation in the arid Ejina Delta: evidences from satellite evapotranspiration

NASA Astrophysics Data System (ADS)

Kai, Lu; Garcia, Monica; Yu, Jingjie; Zhang, Yichi; Wang, Ping; Wang, Sheng; Liu, Xiao

2017-04-01

The ecological water conveyance project (EWCP) in the Ejina delta, a typical hyper-arid area of China, aimed to restore degraded phreatophytic ecosystems. We assessed the degree of ecosystem recovery using as an ecohydrological indicator a ratio between actual and potential evapotranspiration derived from MODIS since the beginning of the project in 2001. The selected indicator was the Temperature Vegetation Dryness Index (TVDI) which was validated with Eddy covariance (EC) data confirming its applicability to monitor groundwater dependent vegetation. The spatial analyses of the evapotranspiration ratio show drying trends (2000-2015) which are stronger and also cover larger extensions than the wetting trends. Thus, the condition of key riparian areas relying mostly on surface water improved since the project began. However, groundwater dependent ecosystems located in lower river Xihe reaches present drying trends. It seems that despite of the runoff supplemented by the EWCP project, there is nowadays more inequality in the access to water by groundwater dependent ecosystems in the Ejina Delta. The study shows that energy-evaporation indices, relying on radiometric satellite temperature like the TVDI, can detect degradation signals that otherwise might go undetected by NDVI analyses especially in arid regions, where vegetation indices are greatly affected by the soil background signals. Additionally, they can provide timely information to water managers on how much water to allocate for a sustainable restoration program.

Assessment of CTAS ETA prediction capabilities

NASA Astrophysics Data System (ADS)

Bolender, Michael A.

1994-11-01

This report summarizes the work done to date in assessing the trajectory fidelity and estimated time of arrival (ETA) prediction capability of the NASA Ames Center TRACON Automation System (CTAS) software. The CTAS software suite is a series of computer programs designed to aid air traffic controllers in their tasks of safely scheduling the landing sequence of approaching aircraft. in particular, this report concerns the accuracy of the available measurements (e.g., position, altitude, etc.) that are input to the software, as well as the accuracy of the final data that is made available to the air traffic controllers.

Emulation of recharge and evapotranspiration processes in shallow groundwater systems

NASA Astrophysics Data System (ADS)

Doble, Rebecca C.; Pickett, Trevor; Crosbie, Russell S.; Morgan, Leanne K.; Turnadge, Chris; Davies, Phil J.

2017-12-01

In shallow groundwater systems, recharge and evapotranspiration are highly sensitive to changes in the depth to water table. To effectively model these fluxes, complex functions that include soil and vegetation properties are often required. Model emulation (surrogate modelling or meta-modelling) can provide a means of incorporating detailed conceptualisation of recharge and evapotranspiration processes, while maintaining the numerical tractability and computational performance required for regional scale groundwater models and uncertainty analysis. A method for emulating recharge and evapotranspiration processes in groundwater flow models was developed, and applied to the South East region of South Australia and western Victoria, which is characterised by shallow groundwater, wetlands and coastal lakes. The soil-vegetation-atmosphere transfer (SVAT) model WAVES was used to generate relationships between net recharge (diffuse recharge minus evapotranspiration from groundwater) and depth to water table for different combinations of climate, soil and land cover types. These relationships, which mimicked previously described soil, vegetation and groundwater behaviour, were combined into a net recharge lookup table. The segmented evapotranspiration package in MODFLOW was adapted to select values of net recharge from the lookup table depending on groundwater depth, and the climate, soil and land use characteristics of each cell. The model was found to be numerically robust in steady state testing, had no major increase in run time, and would be more efficient than tightly-coupled modelling approaches. It made reasonable predictions of net recharge and groundwater head compared with remotely sensed estimates of net recharge and a standard MODFLOW comparison model. In particular, the method was better able to predict net recharge and groundwater head in areas with steep hydraulic gradients.

Effects of daily precipitation and evapotranspiration patterns on flow and VOC transport to groundwater along a watershed flow path

USGS Publications Warehouse

Johnson, Richard L.; Thoms, R.B.; Zogorski, J.S.

2003-01-01

MTBE and other volatile organic compounds (VOCs) are widely observed in shallow groundwater in the United States, especially in urban areas. Previous studies suggest that the atmosphere and/or nonpoint surficial sources could be responsible for some of those VOCs, especially in areas where there is net recharge to groundwater. However, in semi-arid locations where annual potential evapotranspiration can exceed annual precipitation, VOC detections in groundwater can be frequent. VOC transport to groundwater under net discharge conditions has not previously been examined. A numerical model is used here to demonstrate that daily precipitation and evapotranspiration (ET) patterns can have a significant effect on recharge to groundwater, water table elevations, and VOC transport. Ten-year precipitation/ET scenarios from six sites in the United States are examined using both actual daily observed values and “average” pulsed precipitation. MTBE and tetrachloroethylene transport, including gas-phase diffusion, are considered. The effects of the precipitation/ET scenarios on net recharge and groundwater flow are significant and complicated, especially under low-precipitation conditions when pulsed precipitation can significantly underestimate transport to groundwater. In addition to precipitation and evapotranspiration effects, location of VOC entry into the subsurface within the watershed is important for transport in groundwater. This is caused by groundwater hydraulics at the watershed scale as well as variations in ET within the watershed. The model results indicate that it is important to consider both daily precipitation/ET patterns and location within the watershed in order to interpret VOC occurrence in groundwater, especially in low-precipitation settings.

Comparing different methods for determining forest evapotranspiration and its components at multiple temporal scales.

PubMed

Tie, Qiang; Hu, Hongchang; Tian, Fuqiang; Holbrook, N Michele

2018-08-15

Accurately estimating forest evapotranspiration and its components is of great importance for hydrology, ecology, and meteorology. In this study, a comparison of methods for determining forest evapotranspiration and its components at annual, monthly, daily, and diurnal scales was conducted based on in situ measurements in the subhumid mountainous forest of North China. The goal of the study was to evaluate the accuracies and reliabilities of the different methods. The results indicate the following: (1) The sap flow upscaling procedure, taking into account diversities in forest types and tree species, produced component-based forest evapotranspiration estimate that agreed with eddy covariance-based estimate at the temporal scales of year, month, and day, while soil water budget-based forest evapotranspiration estimate was also qualitatively consistent with eddy covariance-based estimate at the daily scale; (2) At the annual scale, catchment water balance-based forest evapotranspiration estimate was significantly higher than eddy covariance-based estimate, which might probably result from non-negligible subsurface runoff caused by the widely distributed regolith and fractured bedrock under the ground; (3) At the sub-daily scale, the diurnal course of sap flow based-canopy transpiration estimate lagged significantly behind eddy covariance-based forest evapotranspiration estimate, which might physiologically be due to stem water storage and stem hydraulic conductivity. The results in this region may have much referential significance for forest evapotranspiration estimation and method evaluation in regions with similar environmental conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

Eta Sigma Gamma: Preparing Leaders Today for Tomorrow's Challenges

ERIC Educational Resources Information Center

Brown, Kelli McCormack

2007-01-01

There is no one definition for a leader or for leadership, but most people can identify a leader and can provide qualities of a good leader or good leadership. The founders of Eta Gamma Gamma--William Bock, Warren Schaller, and Robert Synovitz--all displayed a critical characteristic of leadership by having and acting on a vision. Leadership has…

Minute Temperature Fluctuations Detected in Eta Bootis

NASA Astrophysics Data System (ADS)

1994-11-01

, even in the very brightest stars. Faced with this problem, the Danish/ESO group came up with an entirely new method. It relies on the fact that the oscillations are sound waves which deposit energy in the various stellar layers and therefore intermittently heat the star very slightly. For example, each mode changes the temperature on the surface of the Sun by about 0.005 degrees during the oscillation. But how to measure such small temperature changes? It turns out that this is possible by recording the strengths of the spectral lines, specifically, the absorption lines due to hydrogen. Their strengths change slightly with the changes in temperature (see Appendix). Although this is still a very small effect, it should be easier to measure than the velocity shifts. Yes, Eta Bootis does! To test their method, the astronomers used the ESO 3.5-metre New Technology Telescope (NTT) with the ESO Multi-Mode Instrument (EMMI) to observe a bright star for a few hours. This was too short to detect actual oscillations, but it did show that the technique works: it was in principle possible to measure the temperature accurately enough. The target for the real observations was the 2.68-magnitude, naked-eye star Eta Bootis (Greek letter "eta"). It has the common name of Muphrid and is located just north of the celestial equator in Bootes, one of the oldest constellation names still in use (it was mentioned already in the Odyssey). This particular star is somewhat more evolved and bigger than the Sun and, according to stellar theory, should have stronger oscillations than the Sun, hence increasing the chance that they could be detected. The observations were performed with the 2.5-metre Nordic Optical Telescope (NOT) during six, mostly clear nights in April 1994. A careful data analysis has now shown that the temperature of Eta Bootis is indeed changing periodically, around a mean value of about 6000 K. It seems to be oscillating in at least ten different modes simultaneously, with

Much NICER Monitoring of the X-ray Spectrum of Eta Carinae

NASA Astrophysics Data System (ADS)

Corcoran, Michael Francis; Hamaguchi, Kenji; Drake, Stephen; Pasham, Dheeraj; Gendreau, Keith C.; Arzoumanian, Zaven

2018-01-01

Eta Carinae is the most massive and luminous stellar system within 3 kpc. It is a known binary system with an orbital period of 5.52 years in which bright, thermal, X-ray emission is produced by a strong shock driven by the collisions of the wind of the visible primary star with the thin, fast wind of an otherwise unseen companion. Variations of the X-ray spectrum are produced by intrinsic changes in the density of the hot shocked gas and by intervening changes in wind absorption as the two stars revolve in a long-period, highly eccentric orbit. Previous X-ray monitoring studies since 1996 have detailed these variations, but have been either restricted to the E>3 keV band or have been affected by optical loading which limited measurement of X-ray absorption changes which can be used to determine the overlying density profile of the primary's wind around the orbit. The Neutron Star Interior Composition Explorer (NICER) is an excellent general-purpose observatory for X-ray astronomy, and in particular, its soft response and large effective area facilitate monitoring of X-ray spectral variations for bright sources like Eta Car without any bias due to photon pileup. We present the first observations of the X-ray spectrum of Eta Car obtained by NICER, and discuss limits on changes in column density, emission measure and temperature we derive from the NICER spectra.

Evaluation of the 29-km Eta Model for Weather Support to the United States Space Program

NASA Technical Reports Server (NTRS)

Manobianco, John; Nutter, Paul

1997-01-01

The Applied Meteorology Unit (AMU) conducted a year-long evaluation of NCEP's 29-km mesoscale Eta (meso-eta) weather prediction model in order to identify added value to forecast operations in support of the United States space program. The evaluation was stratified over warm and cool seasons and considered both objective and subjective verification methodologies. Objective verification results generally indicate that meso-eta model point forecasts at selected stations exhibit minimal error growth in terms of RMS errors and are reasonably unbiased. Conversely, results from the subjective verification demonstrate that model forecasts of developing weather events such as thunderstorms, sea breezes, and cold fronts, are not always as accurate as implied by the seasonal error statistics. Sea-breeze case studies reveal that the model generates a dynamically-consistent thermally direct circulation over the Florida peninsula, although at a larger scale than observed. Thunderstorm verification reveals that the meso-eta model is capable of predicting areas of organized convection, particularly during the late afternoon hours but is not capable of forecasting individual thunderstorms. Verification of cold fronts during the cool season reveals that the model is capable of forecasting a majority of cold frontal passages through east central Florida to within +1-h of observed frontal passage.

Estimation of Regional Evapotranspiration Using Remotely Sensed Land Surface Temperature. Part 2: Application of Equilibrium Evaporation Model to Estimate Evapotranspiration by Remote Sensing Technique. [Japan

NASA Technical Reports Server (NTRS)

Kotoda, K.; Nakagawa, S.; Kai, K.; Yoshino, M. M.; Takeda, K.; Seki, K.

1985-01-01

In a humid region like Japan, it seems that the radiation term in the energy balance equation plays a more important role for evapotranspiration then does the vapor pressure difference between the surface and lower atmospheric boundary layer. A Priestley-Taylor type equation (equilibrium evaporation model) is used to estimate evapotranspiration. Net radiation, soil heat flux, and surface temperature data are obtained. Only temperature data obtained by remotely sensed techniques are used.

Geohydrology and evapotranspiration at Franklin Lake playa, Inyo County, California; with a section on estimating evapotranspiration using the energy-budget eddy-correlation technique

USGS Publications Warehouse

Czarnecki, John B.; Stannard, David I.

1997-01-01

Franklin Lake playa is one of the principal discharge areas of the ground-water-flow system associated with Yucca Mountain, Nevada, the potential site of a high-level nuclear-waste repository. By using the energy-budget eddy-correlation technique, measurements made between June 1983 and April 1984 to estimate evapotranspiration were found to range from 0.1 centimeter per day during winter months to about 0.3 centimeter per day during summer months; the annual average was 0.16 centimeter per day. These estimates were compared with evapotranspiration estimates calculated from six other methods.

The epistemic and aleatory uncertainties of the ETAS-type models: an application to the Central Italy seismicity.

PubMed

Lombardi, A M

2017-09-18

Stochastic models provide quantitative evaluations about the occurrence of earthquakes. A basic component of this type of models are the uncertainties in defining main features of an intrinsically random process. Even if, at a very basic level, any attempting to distinguish between types of uncertainty is questionable, an usual way to deal with this topic is to separate epistemic uncertainty, due to lack of knowledge, from aleatory variability, due to randomness. In the present study this problem is addressed in the narrow context of short-term modeling of earthquakes and, specifically, of ETAS modeling. By mean of an application of a specific version of the ETAS model to seismicity of Central Italy, recently struck by a sequence with a main event of Mw6.5, the aleatory and epistemic (parametric) uncertainty are separated and quantified. The main result of the paper is that the parametric uncertainty of the ETAS-type model, adopted here, is much lower than the aleatory variability in the process. This result points out two main aspects: an analyst has good chances to set the ETAS-type models, but he may retrospectively describe and forecast the earthquake occurrences with still limited precision and accuracy.

[Effects of marshland reclamation on evapotranspiration in the Sanjiang Plain].

PubMed

Jia, Zhi-jun; Zhang, Wen; Huang, Yao; Zhao, Xiao-song; Song, Chang-chun

2010-04-01

Extensive reclamation of marshland into cropland has had tremendous effects on the ecological environment in the Sanjiang Plain. Observations over marshland, rice paddy and soybean field were made with eddy covariance measuring systems from May to October in 2005, 2006 and 2007. The objective of this study was to identify the effects of the conversion of marshland to cropland on evapotranspiration in the Sanjiang Plain. The results showed that the diurnal variation curves of latent heat flux were single peaked in marshland, rice paddy and soybean field. The daily maximum latent heat flux increased by 14%-130% in rice paddy in the three measuring years, however, in soybean field, it increased by 3%-77% in 2006 but decreased by 25%-40% in 2005 and 2007 by comparison with that in marshland. This difference was due to the change of leaf area index when marshland was reclaimed into cropland. Seasonal change of latent heat flux was identical for the three land use types. Daily averaged latent heat flux of rice paddy, from May to October, showed 38%-53% increase compared with that of marshland, which resulted from the increase in net radiation and leaf area index. When marshland was reclaimed into soybean field, the variation of daily averaged latent heat flux depended primarily on precipitation. Precipitation was the main factor that controlled evapotranspiration over soybean field which was usually in condition of soil water deficit. Drought caused 11%-17% decrease of daily averaged latent heat flux over soybean field in 2005 and 2007, while sufficient precipitation caused 22% increase in 2006, comparing to marshland. Similarly, during the growing season from June to September, total evapotranspiration of rice paddy increased by 24%-51% compared with that of marshland, and the total evapotranspiration of soybean field decreased by 19%-23% in 2005 and 2007 and increased by 19% in 2006. It is concluded that the evapotranspiration changes significantly when the marshland

Improved ETA-II accelerator performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul, A C; Boyd, J K; Chen, Y J

1999-03-22

Improvements have been made in the performance of the ETA-II accelerator that allow a nominal 2 kA, 6 MeV beam to be focused to a spot size less that 1 mm in diameter. The improvements include reducing the energy sweep to less than +/- 0.5 & over 40 ns of the pulse using a real time energy diagnostic and improving the magnetic tune of the accelerator to reduce the emittance to 8 cm-mrad. Finally, an automated tuning system (MAESTRO) was run to minimize the time dependent centroid motion (corkscrew) by adjusting the steering dipoles over the focusing solenoids. The corkscrewmore » motion was reduced to less than +/- 0.5 mm at the output of the accelerator.« less

PERFORMANCE AND DIAGNOSTIC EVALUATION OF OZONE PREDICTIONS BY THE ETA-COMMUNITY MULTISCALE AIR QUALITY FORECAST SYSTEM DURING THE 2002 NEW ENGLAND AIR QUALITY STUDY

EPA Science Inventory

A real-time air quality forecasting system (Eta-CMAQ model suite) has been developed by linking the NCEP Eta model to the U.S. EPA CMAQ model. This work presents results from the application of the Eta-CMAQ modeling system for forecasting O₃ over the northeastern U.S d...

Eta Carinae in the Context of the Most Massive Stars

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Damineli, Augusto

2009-01-01

Eta Car, with its historical outbursts, visible ejecta and massive, variable winds, continues to challenge both observers and modelers. In just the past five years over 100 papers have been published on this fascinating object. We now know it to be a massive binary system with a 5.54-year period. In January 2009, Car underwent one of its periodic low-states, associated with periastron passage of the two massive stars. This event was monitored by an intensive multi-wavelength campaign ranging from -rays to radio. A large amount of data was collected to test a number of evolving models including 3-D models of the massive interacting winds. August 2009 was an excellent time for observers and theorists to come together and review the accumulated studies, as have occurred in four meetings since 1998 devoted to Eta Car. Indeed, Car behaved both predictably and unpredictably during this most recent periastron, spurring timely discussions. Coincidently, WR140 also passed through periastron in early 2009. It, too, is a intensively studied massive interacting binary. Comparison of its properties, as well as the properties of other massive stars, with those of Eta Car is very instructive. These well-known examples of evolved massive binary systems provide many clues as to the fate of the most massive stars. What are the effects of the interacting winds, of individual stellar rotation, and of the circumstellar material on what we see as hypernovae/supernovae? We hope to learn. Topics discussed in this 1.5 day Joint Discussion were: Car: the 2009.0 event: Monitoring campaigns in X-rays, optical, radio, interferometry WR140 and HD5980: similarities and differences to Car LBVs and Eta Carinae: What is the relationship? Massive binary systems, wind interactions and 3-D modeling Shapes of the Homunculus & Little Homunculus: what do we learn about mass ejection? Massive stars: the connection to supernovae, hypernovae and gamma ray bursters Where do we go from here? (future

Potential evapotranspiration and continental drying

USGS Publications Warehouse

Milly, Paul C.D.; Dunne, Krista A.

2016-01-01

By various measures (drought area and intensity, climatic aridity index, and climatic water deficits), some observational analyses have suggested that much of the Earth’s land has been drying during recent decades, but such drying seems inconsistent with observations of dryland greening and decreasing pan evaporation. ‘Offline’ analyses of climate-model outputs from anthropogenic climate change (ACC) experiments portend continuation of putative drying through the twenty-first century, despite an expected increase in global land precipitation. A ubiquitous increase in estimates of potential evapotranspiration (PET), driven by atmospheric warming, underlies the drying trends, but may be a methodological artefact. Here we show that the PET estimator commonly used (the Penman–Monteith PET for either an open-water surface or a reference crop) severely overpredicts the changes in non-water-stressed evapotranspiration computed in the climate models themselves in ACC experiments. This overprediction is partially due to neglect of stomatal conductance reductions commonly induced by increasing atmospheric CO2 concentrations in climate models. Our findings imply that historical and future tendencies towards continental drying, as characterized by offline-computed runoff, as well as other PET-dependent metrics, may be considerably weaker and less extensive than previously thought.

The ETA-II induction linac as a high-average-power FEL driver

NASA Astrophysics Data System (ADS)

Nexsen, W. E.; Atkinson, D. P.; Barrett, D. M.; Chen, Y.-J.; Clark, J. C.; Griffith, L. V.; Kirbie, H. C.; Newton, M. A.; Paul, A. C.; Sampayan, S.; Throop, A. L.; Turner, W. C.

1990-10-01

The Experimental Test Accelerator II (ETA-II) is the first induction linac designed specifically to FEL requirements. It is primarily intended to demonstrate induction accelerator technology for high-average-power, high-brightness electron beams, and will be used to drive a 140 and 250 GHz microwave FEL for plasma heating experiments in the Microwave Tokamak Experiment (MTX) at LLNL. Its features include high-vacuum design which allows the use of an intrinsically bright dispenser cathode, induction cells designed to minimize BBU growth rate, and careful attention to magnetic alignment to minimize radial sweep due to beam corkscrew. The use of magnetic switches allows high-average-power operation. At present ETA-II is being used to drive 140 GHz plasma heating experiments. These experiments require nominal beam parameters of 6 MeV energy, 2 kA current, 20 ns pulse width and a brightness of 1 × 108 A/(m rad)2 at the wiggler with a pulse repetition frequency (prf) of 0.5 Hz. Future 250 GHz experiments require beam parameters of 10 MeV energy, 3 kA current, 50 ns pulse width and a brightness of 1 × 108 A/(m rad)2 with a 5 kHz prf for 0.5 s. In this paper we discuss the present status of ETA-II parameters and the phased development program necessary to satisfy these future requirements.

Sub-canopy evapotranspiration from floating vegetation and open water in a swamp forest

USDA-ARS?s Scientific Manuscript database

Among previous studies, there are large discrepancies in the difference between evapotranspiration from wetland vegetation and evaporation from open water. In this study, we investigate evapotranspiration differences between water and vegetation in a scenario that has otherwise not been extensively ...

Estimation of evapotranspiration rate in irrigated lands using stable isotopes

NASA Astrophysics Data System (ADS)

Umirzakov, Gulomjon; Windhorst, David; Forkutsa, Irina; Brauer, Lutz; Frede, Hans-Georg

2013-04-01

Agriculture in the Aral Sea basin is the main consumer of water resources and due to the current agricultural management practices inefficient water usage causes huge losses of freshwater resources. There is huge potential to save water resources in order to reach a more efficient water use in irrigated areas. Therefore, research is required to reveal the mechanisms of hydrological fluxes in irrigated areas. This paper focuses on estimation of evapotranspiration which is one of the crucial components in the water balance of irrigated lands. Our main objective is to estimate the rate of evapotranspiration on irrigated lands and partitioning of evaporation into transpiration using stable isotopes measurements. Experiments has done in 2 different soil types (sandy and sandy loam) irrigated areas in Ferghana Valley (Uzbekistan). Soil samples were collected during the vegetation period. The soil water from these samples was extracted via a cryogenic extraction method and analyzed for the isotopic ratio of the water isotopes (2H and 18O) based on a laser spectroscopy method (DLT 100, Los Gatos USA). Evapotranspiration rates were estimated with Isotope Mass Balance method. The results of evapotranspiration obtained using isotope mass balance method is compared with the results of Catchment Modeling Framework -1D model results which has done in the same area and the same time.

Validating Remotely Sensed Land Surface Evapotranspiration Based on Multi-scale Field Measurements

NASA Astrophysics Data System (ADS)

Jia, Z.; Liu, S.; Ziwei, X.; Liang, S.

2012-12-01

The land surface evapotranspiration plays an important role in the surface energy balance and the water cycle. There have been significant technical and theoretical advances in our knowledge of evapotranspiration over the past two decades. Acquisition of the temporally and spatially continuous distribution of evapotranspiration using remote sensing technology has attracted the widespread attention of researchers and managers. However, remote sensing technology still has many uncertainties coming from model mechanism, model inputs, parameterization schemes, and scaling issue in the regional estimation. Achieving remotely sensed evapotranspiration (RS_ET) with confident certainty is required but difficult. As a result, it is indispensable to develop the validation methods to quantitatively assess the accuracy and error sources of the regional RS_ET estimations. This study proposes an innovative validation method based on multi-scale evapotranspiration acquired from field measurements, with the validation results including the accuracy assessment, error source analysis, and uncertainty analysis of the validation process. It is a potentially useful approach to evaluate the accuracy and analyze the spatio-temporal properties of RS_ET at both the basin and local scales, and is appropriate to validate RS_ET in diverse resolutions at different time-scales. An independent RS_ET validation using this method was presented over the Hai River Basin, China in 2002-2009 as a case study. Validation at the basin scale showed good agreements between the 1 km annual RS_ET and the validation data such as the water balanced evapotranspiration, MODIS evapotranspiration products, precipitation, and landuse types. Validation at the local scale also had good results for monthly, daily RS_ET at 30 m and 1 km resolutions, comparing to the multi-scale evapotranspiration measurements from the EC and LAS, respectively, with the footprint model over three typical landscapes. Although some

Field demonstration of the combined effects of absorption and evapotranspiration on septic system drainfield capacity.

PubMed

Rainwater, Ken; Jackson, Andrew; Ingram, Wesley; Lee, Chang Yong; Thompson, David; Mollhagen, Tony; Ramsey, Heyward; Urban, Lloyd

2005-01-01

Drainfields for disposal of septic tank effluents are typically designed by considering the loss of water by either upward evapotranspiration into the atmosphere or lateral and downward absorption into the adjacent soil. While this approach is appropriate for evapotranspiration systems, absorption systems allow water loss by both mechanisms. It was proposed that, in areas where high evapotranspiration rates coincide with permeable soils, drainfield sizes could be substantially reduced by accounting for both mechanisms. A two-year field demonstration was conducted to determine appropriate design criteria for areas typical of the Texas High Plains. The study consisted of evaluating the long-term acceptance rates for three different drainfield configurations: evapotranspiration only, absorption only, and combined conditions. A second field demonstration repeated the experiments for additional observation of the combined evapotranspiration and absorption and achieved similar results as the first study. The field tests indicated that the current design loading criteria may be increased by at least a factor of two for the Texas High Plains region and other Texas areas with similar soil composition and evapotranspiration rates, while still retaining a factor of safety of two.

Improving Evapotranspiration Estimates Using Multi-Platform Remote Sensing

NASA Astrophysics Data System (ADS)

Knipper, Kyle; Hogue, Terri; Franz, Kristie; Scott, Russell

2016-04-01

Understanding the linkages between energy and water cycles through evapotranspiration (ET) is uniquely challenging given its dependence on a range of climatological parameters and surface/atmospheric heterogeneity. A number of methods have been developed to estimate ET either from primarily remote-sensing observations, in-situ measurements, or a combination of the two. However, the scale of many of these methods may be too large to provide needed information about the spatial and temporal variability of ET that can occur over regions with acute or chronic land cover change and precipitation driven fluxes. The current study aims to improve the spatial and temporal variability of ET utilizing only satellite-based observations by incorporating a potential evapotranspiration (PET) methodology with satellite-based down-scaled soil moisture estimates in southern Arizona, USA. Initially, soil moisture estimates from AMSR2 and SMOS are downscaled to 1km through a triangular relationship between MODIS land surface temperature (MYD11A1), vegetation indices (MOD13Q1/MYD13Q1), and brightness temperature. Downscaled soil moisture values are then used to scale PET to actual ET (AET) at a daily, 1km resolution. Derived AET estimates are compared to observed flux tower estimates, the North American Land Data Assimilation System (NLDAS) model output (i.e. Variable Infiltration Capacity (VIC) Macroscale Hydrologic Model, Mosiac Model, and Noah Model simulations), the Operational Simplified Surface Energy Balance Model (SSEBop), and a calibrated empirical ET model created specifically for the region. Preliminary results indicate a strong increase in correlation when incorporating the downscaling technique to original AMSR2 and SMOS soil moisture values, with the added benefit of being able to decipher small scale heterogeneity in soil moisture (riparian versus desert grassland). AET results show strong correlations with relatively low error and bias when compared to flux tower

Modeling seasonal water balance based on catchments' hedging strategy on evapotranspiration for climate seasonality

NASA Astrophysics Data System (ADS)

Wu, S.; Zhao, J.; Wang, H.

2017-12-01

This paper develops a seasonal water balance model based on the hypothesis that natural catchments utilize hedging strategy on evapotranspiration for climate seasonality. According to the monthly aridity index, one year is split into wet season and dry season. A seasonal water balance model is developed by analogy to a two-stage reservoir operation model, in which seasonal rainfall infiltration, evapotranspiration and saturation-excess runoff is corresponding to the inflow, release and surplus of the catchment system. Then the optimal hedging between wet season and dry season evapotranspiration is analytically derived with marginal benefit principle. Water budget data sets of 320 catchments in the United States covering the period from 1980 to 2010 are used to evaluate the performance of this model. The Nash-Sutcliffe Efficiency coefficient for evapotranspiration is higher than 0.5 in 84% of the study catchments; while the runoff is 87%. This paper validates catchments' hedging strategy on evapotranspiration for climate seasonality and shows its potential application for seasonal water balance, which is valuable for water resources planning and management.

Recent X-ray Variability of Eta Car Approaching The X-ray Eclipse

NASA Technical Reports Server (NTRS)

Corcoran, M.; Swank, J. H.; Ishibashi, K.; Gull, T.; Humphreys, R.; Damineli, A.; Walborn, N.; Hillier, D. J.; Davidson, K.; White, S. M.

2002-01-01

We discuss recent X-ray spectral variability of the supermassive star Eta Car in the interval since the last X-ray eclipse in 1998. We concentrate on the interval just prior to the next X-ray eclipse which is expected to occur in June 2003. We compare the X-ray behavior during the 2001-2003 cycle with the previous cycle (1996-1998) and note similarities and differences in the temporal X-ray behavior. We also compare a recent X-ray observation of Eta Car obtained with the Chandra high energy transmission grating in October 2002 with an earlier observation from Nov 2002, and interpret these results in terms of the proposed colliding wind binary model for the star. In addition we discuss planned observations for the upcoming X-ray eclipse.

Targeting Inaccurate Atomic Data in the Eta Car Ejecta Absorption

NASA Technical Reports Server (NTRS)

Nielsen, K. E.; Kober, G. Vieira; Gull, T. R.; Blackwell-Whitehead, R.; Nilsson, H.

2006-01-01

The input from the laboratory spectroscopist community has on many occasions helped the analysis of the eta Car spectrum. Our analysis has targeted spectra where improved wavelengths and oscillator strengths are needed. We will demonstrate how experimentally derived atomic data have improved our spectral analysis, and illuminate where more work still is needed.

Looking for a relevant potential evapotranspiration model at the watershed scale

NASA Astrophysics Data System (ADS)

Oudin, L.; Hervieu, F.; Michel, C.; Perrin, C.; Anctil, F.; Andréassian, V.

2003-04-01

In this paper, we try to identify the most relevant approach to calculate Potential Evapotranspiration (PET) for use in a daily watershed model, to try to bring an answer to the following question: "how can we use commonly available atmospheric parameters to represent the evaporative demand at the catchment scale?". Hydrologists generally see the Penman model as the ideal model regarding to its good adequacy with lysimeter measurements and its physically-based formulation. However, in real-world engineering situations, where meteorological stations are scarce, hydrologists are often constrained to use other PET formulae with less data requirements or/and long-term average of PET values (the rationale being that PET is an inherently conservative variable). We chose to test 28 commonly used PET models coupled with 4 different daily watershed models. For each test, we compare both PET input options: actual data and long-term average data. The comparison is made in terms of streamflow simulation efficiency, over a large sample of 308 watersheds. The watersheds are located in France, Australia and the United States of America and represent varied climates. Strikingly, we find no systematic improvements of the watershed model efficiencies when using actual PET series instead of long-term averages. This suggests either that watershed models may not conveniently use the climatic information contained in PET values or that formulae are only awkward indicators of the real PET which watershed models need.

Endothelin ETA receptor/lipid peroxides/COX-2/TGF-β1 signalling underlies aggravated nephrotoxicity caused by cyclosporine plus indomethacin in rats.

PubMed

Helmy, Maged W; El-Gowelli, Hanan M; Ali, Rabab M; El-Mas, Mahmoud M

2015-09-01

Cyclosporine (CSA) and non-steroidal anti-inflammatory drugs (NSAIDs) are co-prescribed for some arthritic conditions. We tested the hypothesis that this combined regimen elicits exaggerated nephrotoxicity in rats via the up-regulation of endothelin (ET) receptor signalling. The effects of a 10 day treatment with CSA (20 mg · kg(-1) · day(-1)), indomethacin (5 mg · kg(-1) · day(-1)) or their combination on renal biochemical, inflammatory, oxidative and structural profiles were assessed. The roles of ETA receptor and COX-2 pathways in the interaction were evaluated. Oral treatment with CSA or indomethacin elevated serum urea and creatinine, caused renal tubular atrophy and interstitial fibrosis, increased renal TGF-β1, and reduced immunohistochemical expressions of ETA receptors and COX-2. CSA, but not indomethacin, increased renal ET-1, the lipid peroxidation product malondialdehyde (MDA) and GSH activity. Compared with individual treatments, simultaneous CSA/indomethacin exposure caused: (i) greater elevations in serum creatinine and renal MDA; (ii) loss of the compensatory increase in GSH; (iii) renal infiltration of inflammatory cells and worsening of fibrotic and necrotic profiles; and (iv) increased renal ET-1 and decreased ETA receptor and COX-2 expressions. Blockade of ETA receptors by atrasentan ameliorated the biochemical, structural, inflammatory and oxidative abnormalities caused by the CSA/indomethacin regimen. Furthermore, atrasentan partly reversed the CSA/indomethacin-evoked reductions in the expression of ETA receptor and COX-2 protein. The exaggerated oxidative insult and associated dysregulation of the ETA receptor/COX-2/TGF-β1 signalling might account for the aggravated nephrotoxicity caused by the CSA/indomethacin regimen. The potential renoprotective effect of ETA receptor antagonism might be exploited therapeutically. © 2015 The British Pharmacological Society.

X-rays from Eta Carinae

NASA Technical Reports Server (NTRS)

Chlebowski, T.; Seward, F. D.; Swank, J.; Szymkowiak, A.

1984-01-01

X-ray observations of Eta Car obtained with the high-resolution imager and solid-state spectrometer of the Einstein observatory are reported and interpreted in terms of a two-shell model. A soft component with temperature 5 million K is located in the expanding outer shell, and the hard core component with temperature 80 million K is attributed to the interaction of a high-velocity stellar wind from the massive central object with the inner edge of a dust shell. Model calculations based on comparison with optical and IR data permit estimation of the mass of the outer shell (0.004 solar mass), the mass of the dust shell (3 solar mass), and the total shell expansion energy (less than 2 x 10 to the 49th ergs).

Downscaling Coarse Actual ET Data Using Land Surface Resistance

NASA Astrophysics Data System (ADS)

Shen, T.

2017-12-01

This study proposed a new approach of downscaling ETWATCH 1km actual evapotranspiration (ET) product to a spatial resolution of 30m using land surface resistance that simulated mainly from monthly Landsat8 data and Jarvis method, which combined the benefits of both high temporal resolution of ETWATCH product and fine spatial resolution of Landsat8. The driving factor, surface resistance (Rs), was chosen for the reason that could reflect the transfer ability of vapor flow over canopy. Combined resistance Rs both upon canopy conditions, atmospheric factors and available water content of soil, which remains stable inside one ETWATCH pixel (1km). In this research, we used ETWATCH 1km ten-day actual ET product from April to October in a total of twenty-one images and monthly 30 meters cloud-free NDVI of 2013 (two images from HJ as a substitute due to cloud contamination) combined meteorological indicators for downscaling. A good agreement and correlation were obtained between the downscaled data and three flux sites observation in the middle reach of Heihe basin. The downscaling results show good consistency with the original ETWATCH 1km data both temporal and spatial scale over different land cover types with R2 ranged from 0.8 to 0.98. Besides, downscaled result captured the progression of vegetation transpiration well. This study proved the practicability of new downscaling method in the water resource management.

Eta Carinae: A Box of Puzzles...Some Solved, Others Await

NASA Technical Reports Server (NTRS)

Gull, Theodore

2010-01-01

In the l840's, Eta Carinae brightened to rival Sirius, then faded. Today we see a marginally naked-eye binary with an expanding, very dusty bipolar Homunculus. The energetics of the ejected mass (>l2 to 40 solar masses at 500-700 km/s plus outer bullets/strings up to 3000 km/s} approach that of a supernova. Extragalactic SN surveys detect near-supernovae thought to be like the Great Eruption of the 1840's. Eta Carinae presents an abundance of puzzles: rich in N, but 1/100th the solar C and O abundances; Ti, V, Sr, Sc persist in atomic states.... yet an abundance of molecules and dust exists in the Homunculus. How did molecules and dust form with low C and O? A near supernova occurred in the l840m, yet both binary companions, with total mass > 120 solar masses, survive in a very eccentric orbit. What is the near future of this system: a GRB? a SN? or just two WR stars that ultimately become two SNs? These and other puzzles will be presented

Soil moisture and evapotranspiration predictions using Skylab data

NASA Technical Reports Server (NTRS)

Myers, V. I. (Principal Investigator); Moore, D. G.; Horton, M. L.; Russell, M. J.

1975-01-01

The author has identified the following significant results. Multispectral reflectance and emittance data from the Skylab workshop were evaluated for prediction of evapotranspiration and soil moisture for an irrigated region of southern Texas. Wavelengths greater than 2.1 microns were required to spectrally distinguish between wet and dry fallow surfaces. Thermal data provided a better estimate of soil moisture than did data from the reflective bands. Thermal data were dependent on soil moisture but not on the type of agricultural land use. The emittance map, when used in conjunction with existing models, did provide an estimate of evapotranspiration rates. Surveys of areas of high soil moisture can be accomplished with space altitude thermal data. Thermal data will provide a reliable input into irrigation scheduling.

A scaling approach to Budyko's framework and the complementary relationship of evapotranspiration in humid environments: case study of the Amazon River basin

NASA Astrophysics Data System (ADS)

Carmona, A. M.; Poveda, G.; Sivapalan, M.; Vallejo-Bernal, S. M.; Bustamante, E.

2016-02-01

This paper studies a 3-D state space representation of Budyko's framework designed to capture the mutual interdependence among long-term mean actual evapotranspiration (E), potential evapotranspiration (Ep) and precipitation (P). For this purpose we use three dimensionless and dependent quantities: Ψ = E ⁄ P, Φ = Ep ⁄ P and Ω = E ⁄ Ep. This 3-D space and its 2-D projections provide an interesting setting to test the physical soundness of Budyko's hypothesis. We demonstrate analytically that Budyko-type equations are unable to capture the physical limit of the relation between Ω and Φ in humid environments, owing to the unfeasibility of Ep ⁄ P = 0 when E ⁄ Ep → 1. Using data from 146 sub-catchments in the Amazon River basin we overcome this inconsistency by proposing a physically consistent power law: Ψ = kΦe, with k = 0.66, and e = 0.83 (R2 = 0.93). This power law is compared with two other Budyko-type equations. Taking into account the goodness of fits and the ability to comply with the physical limits of the 3-D space, our results show that the power law is better suited to model the coupled water and energy balances within the Amazon River basin. Moreover, k is found to be related to the partitioning of energy via evapotranspiration in terms of Ω. This suggests that our power law implicitly incorporates the complementary relationship of evapotranspiration into the Budyko curve, which is a consequence of the dependent nature of the studied variables within our 3-D space. This scaling approach is also consistent with the asymmetrical nature of the complementary relationship of evapotranspiration. Looking for a physical explanation for the parameters k and e, the inter-annual variability of individual catchments is studied. Evidence of space-time symmetry in Amazonia emerges, since both between-catchment and between-year variability follow the same Budyko curves. Finally, signs of co-evolution of catchments are explored by

A scaling approach to Budyko's framework and the complementary relationship of evapotranspiration in humid environments: case study of the Amazon River basin

NASA Astrophysics Data System (ADS)

Carmona, A. M.; Poveda, G.; Sivapalan, M.; Vallejo-Bernal, S. M.; Bustamante, E.

2015-10-01

This paper studies a 3-D generalization of Budyko's framework designed to capture the mutual interdependence among long-term mean actual evapotranspiration (E), potential evapotranspiration (Ep) and precipitation (P). For this purpose we use three dimensionless and dependent quantities: Ψ = E/P, Φ = Ep/P and Ω = E/Ep. This 3-D space and its 2-D projections provide an interesting setting to test the physical soundness of Budyko's hypothesis. We demonstrate analytically that Budyko-type equations are unable to capture the physical limit of the relation between Ω and Φ in humid environments, owing to the unfeasibility of Ep/P → 0 at E/Ep = 1. Using data from 146 sub-catchments in the Amazon River basin we overcome this inconsistency by proposing a physically consistent power law: Ψ = k Φe, with k = 0.66, and e = 0.83 (R2 = 0.93). This power law is compared with two other Budyko-type equations. Taking into account the goodness of fits and the ability to comply with the physical limits of the 3-D space, our results show that the power law is better suited to model the coupled water and energy balances within the Amazon River basin. Moreover, k is found to be related to the partitioning of energy via evapotranspiration in terms of Ω. This suggests that our power law implicitly incorporates the complementary relationship of evapotranspiration into the Budyko curve, which is a consequence of the dependent nature of the studied variables within our 3-D space. This scaling approach is also consistent with the asymmetrical nature of the complementary relationship of evapotranspiration. Looking for a physical explanation for the parameters k and e, the inter-annual variability of individual catchments is studied. Evidence of space-time symmetry in Amazonia emerges, since both between-catchment and between-year variability follow the same Budyko curves. Finally, signs of co-evolution of catchments are explored by linking spatial patterns of the power law parameters

SECULAR CHANGES IN ETA CARINAE'S WIND 1998-2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehner, Andrea; Davidson, Kris; Humphreys, Roberta M.

2012-05-20

Stellar wind-emission features in the spectrum of eta Carinae have decreased by factors of 1.5-3 relative to the continuum within the last 10 years. We investigate a large data set from several instruments (STIS, GMOS, UVES) obtained between 1998 and 2011 and analyze the progression of spectral changes in direct view of the star, in the reflected polar-on spectra at FOS4, and at the Weigelt knots. We find that the spectral changes occurred gradually on a timescale of about 10 years and that they are dependent on the viewing angle. The line strengths declined most in our direct view ofmore » the star. About a decade ago, broad stellar wind-emission features were much stronger in our line-of-sight view of the star than at FOS4. After the 2009 event, the wind-emission line strengths are now very similar at both locations. High-excitation He I and N II absorption lines in direct view of the star strengthened gradually. The terminal velocity of Balmer P Cyg absorption lines now appears to be less latitude dependent, and the absorption strength may have weakened at FOS4. Latitude-dependent alterations in the mass-loss rate and the ionization structure of eta Carinae's wind are likely explanations for the observed spectral changes.« less

Vascular Effects of Endothelin Receptor Antagonists Depends on Their Selectivity for ETA Versus ETB Receptors and on the Functionality of Endothelial ETB Receptors.

PubMed

Iglarz, Marc; Steiner, Pauline; Wanner, Daniel; Rey, Markus; Hess, Patrick; Clozel, Martine

2015-10-01

The goal of this study was to characterize the role of Endothelin (ET) type B receptors (ETB) on vascular function in healthy and diseased conditions and demonstrate how it affects the pharmacological activity of ET receptor antagonists (ERAs). The contribution of the ETB receptor to vascular relaxation or constriction was characterized in isolated arteries from healthy and diseased rats with systemic (Dahl-S) or pulmonary hypertension (monocrotaline). Because the role of ETB receptors is different in pathological vis-à-vis normal conditions, we compared the efficacy of ETA-selective and dual ETA/ETB ERAs on blood pressure in hypertensive rats equipped with telemetry. In healthy vessels, ETB receptors stimulation with sarafotoxin S6c induced vasorelaxation and no vasoconstriction. In contrast, in arteries of rats with systemic or pulmonary hypertension, endothelial ETB-mediated relaxation was lost while vasoconstriction on stimulation by sarafotoxin S6c was observed. In hypertensive rats, administration of the dual ETA/ETB ERA macitentan on top of a maximal effective dose of the ETA-selective ERA ambrisentan further reduced blood pressure, indicating that ETB receptors blockade provides additional benefit. Taken together, these data suggest that in pathology, dual ETA/ETB receptor antagonism can provide superior vascular effects compared with ETA-selective receptor blockade.

14-3-3 eta isoform colocalizes TDP-43 on the coarse granules in the anterior horn cells of patients with sporadic amyotrophic lateral sclerosis.

PubMed

Umahara, Takahiko; Uchihara, Toshiki; Shibata, Noriyuki; Nakamura, Ayako; Hanyu, Haruo

2016-09-01

The immunolocalization of the 14-3-3 eta isoform in the anterior horn cells (AHCs) of patients with sporadic amyotrophic lateral sclerosis (ALS) and controls was examined. Compared with the immunolocalization of other 14-3-3 isoforms, the immunolocalization of the 14-3-3 eta isoform was either synaptic at the periphery of AHCs, spindle-shaped in neurites, or granular in the cytoplasm. By double labeling with phosphorylated (p-)TDP-43, the transactivation response DNA binding protein of 43kDa (TDP-43) demonstrated frequent colocalization of the 14-3-3 eta isoform in granular structures (90%) and spindle-shaped structures (85.4%), but not in p-TDP-43-positive round inclusions. It is speculated that the 14-3-3 eta isoform is associated with not only a synaptic pathology of ALS but also TDP-positive small lesions in the cytoplasm and neurites. The absence of eta-like immunoreactivity in p-TDP-43-positive large inclusions suggests the restricted relevance of the 14-3-3 eta isoform during ALS pathogenesis to some phases of the p-TDP pathology. Copyright © 2016 Elsevier B.V. All rights reserved.

Recent X-ray Variability of eta Carinae: the Quick Road to Recovery

NASA Technical Reports Server (NTRS)

Corcoran, M. Francis; Hamaguchi, K.; Pittard, J. M.; Russell, C. M. P.; Owocki, S. P.; Parkin, E. R.; Okazaki, A.

2010-01-01

We report continued monitoring of the superluminous binary system eta Car by the Proportional Counter Array on the Rossi X-ray Timing Observatory (RXTE) through the 2009 X-ray minimum. The RXTE campaign shows that the minimum began on 2009 January 16, consistent with the phasings of the two previous minima, and overall, the temporal behavior of the X-ray emission was similar to that observed by RXTE in the previous two cycles. However, important differences did occur. The 2-10 keV X-ray flux and X-ray hardness decreased in the 2.5-year interval leading up to the 2009 minimum compared to the previous cycle. Most intriguingly, the 2009 X-ray minimum was about one month shorter than either of the previous two minima. During the egress from the 2009 minimum the X-ray hardness increased markedly as it had during egress from the previous two minima, although the maximum X-ray hardness achieved was less than the maximum observed after the two previous recoveries. We suggest that the cycle-to-cycle variations, especially the unexpectedly early recovery from the 2009 X-ray minimum, might have been the result of a decline in eta Car's wind momentum flux produced by a drop in eta Car's mass loss rate or wind terminal velocity (or some combination), though if so the change in wind momentum flux required to match the X-ray variation is surprisingly large.

The ETA-2 induction linac as a high average power FEL driver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nexsen, W.E.; Atkinson, D.P.; Barrett, D.M.

1989-10-16

The Experimental Test Accelerator-II (ETA-II) is the first induction linac designed specifically to FEL requirements. It primarily is intended to demonstrate induction accelerator technology for high average power, high brightness electron beams, and will be used to drive a 140 and 250 GHz microwave FEL for plasma heating experiments in the Microwave Tokamak Experiment (MTX) at LLNL. Its features include high vacuum design which allows the use of an intrinsically bright dispenser cathode, induction cells designed to minimize BBU growth rate, and careful attention to magnetic alignment to minimize radial sweep due to beam corkscrew. The use of magnetic switchesmore » allows high average power operation. At present ETA-II is being used to drive 140 GHz plasma heating experiments. These experiments require nominal beam parameters of 6 Mev energy, 2kA current, 20ns pulse width and a brightness of 1 {times} 10{sup 8} A/(m-rad){sup 2} at the wiggler with a pulse repetition frequency (PRF) of 0.5 Hz. Future 250 GHz experiments require beam parameters of 10 Mev energy, 3kA current, 50ns pulse width and a brightness of 1 {times} 10{sup 8} A/(m-rad){sup 2} with a 5 kHz PRF for 0.5 sec. In this paper we discuss the present status of ETA-II parameters and the phased development program necessary to satisfy these future requirements. 13 refs., 9 figs., 1 tab.« less

Detection of the Compressed Primary Stellar Wind in eta Carinae

NASA Technical Reports Server (NTRS)

Teodoro, Mairan Macedo; Madura, Thomas I.; Gull, Theodore R.; Corcoran, Michael F.; Hamaguchi, K.

2014-01-01

A series of three HST/STIS spectroscopic mappings, spaced approximately one year apart, reveal three partial arcs in [Fe II] and [Ni II] emissions moving outward from eta Carinae. We identify these arcs with the shell-like structures, seen in the 3D hydrodynamical simulations, formed by compression of the primary wind by the secondary wind during periastron passages.

Influence of land-surface evapotranspiration on the earth's climate

NASA Technical Reports Server (NTRS)

Shukla, J.; Mintz, Y.

1982-01-01

Land-surface evapotranspiration is shown to strongly influence global fields of rainfall, temperature and motion by calculations using a numerical model of the atmosphere, confirming the general belief in the importance of evapotranspiration-producing surface vegetation for the earth's climate. The current version of the Goddard Laboratory atmospheric general circulation model is used in the present experiment, in which conservation equations for mass, momentum, moisture and energy are expressed in finite-difference form for a spherical grid to calculate (1) surface pressure field evolution, and (2) the wind, temperature, and water vapor fields at nine levels between the surface and a 20 km height.

Annual regression-based estimates of evapotranspiration for the contiguous United States based on climate, remote sensing, and stream gage data

NASA Astrophysics Data System (ADS)

Reitz, M. D.; Sanford, W. E.; Senay, G. B.; Cazenas, J.

2015-12-01

Evapotranspiration (ET) is a key quantity in the hydrologic cycle, accounting for ~70% of precipitation across the contiguous United States (CONUS). However, it is a challenge to estimate, due to difficulty in making direct measurements and gaps in our theoretical understanding. Here we present a new data-driven, ~1km2 resolution map of long-term average actual evapotranspiration rates across the CONUS. The new ET map is a function of the USGS Landsat-derived National Land Cover Database (NLCD), precipitation, temperature, and daily average temperature range (from the PRISM climate dataset), and is calibrated to long-term water balance data from 679 watersheds. It is unique from previously presented ET maps in that (1) it was co-developed with estimates of runoff and recharge; (2) the regression equation was chosen from among many tested, previously published and newly proposed functional forms for its optimal description of long-term water balance ET data; (3) it has values over open-water areas that are derived from separate mass-transfer and humidity equations; and (4) the data include additional precipitation representing amounts converted from 2005 USGS water-use census irrigation data. The regression equation is calibrated using data from 2000-2013, but can also be applied to individual years with their corresponding input datasets. Comparisons among this new map, the more detailed remote-sensing-based estimates of MOD16 and SSEBop, and AmeriFlux ET tower measurements shows encouraging consistency, and indicates that the empirical ET estimate approach presented here produces closer agreement with independent flux tower data for annual average actual ET than other more complex remote sensing approaches.

The Pattern Across the Continental United States of Evapotranspiration Variability Associated with Water Availability

NASA Technical Reports Server (NTRS)

Koster, Randal D.; Salvucci, Guido D.; Rigden, Angela J.; Jung, Martin; Collatz, G. James; Schubert, Siegfried D.

2015-01-01

The spatial pattern across the continental United States of the interannual variance of warm season water-dependent evapotranspiration, a pattern of relevance to land-atmosphere feedback, cannot be measured directly. Alternative and indirect approaches to estimating the pattern, however, do exist, and given the uncertainty of each, we use several such approaches here. We first quantify the water dependent evapotranspiration variance pattern inherent in two derived evapotranspiration datasets available from the literature. We then search for the pattern in proxy geophysical variables (air temperature, stream flow, and NDVI) known to have strong ties to evapotranspiration. The variances inherent in all of the different (and mostly independent) data sources show some differences but are generally strongly consistent they all show a large variance signal down the center of the U.S., with lower variances toward the east and (for the most part) toward the west. The robustness of the pattern across the datasets suggests that it indeed represents the pattern operating in nature. Using Budykos hydroclimatic framework, we show that the pattern can largely be explained by the relative strength of water and energy controls on evapotranspiration across the continent.

Spatially Distributed Assimilation of Remotely Sensed Leaf Area Index and Potential Evapotranspiration for Hydrologic Modeling in Wetland Landscapes

NASA Astrophysics Data System (ADS)

Rajib, A.; Evenson, G. R.; Golden, H. E.; Lane, C.

2017-12-01

Evapotranspiration (ET), a highly dynamic flux in wetland landscapes, regulates the accuracy of surface/sub-surface runoff simulation in a hydrologic model. Accordingly, considerable uncertainty in simulating ET-related processes remains, including our limited ability to incorporate realistic ground conditions, particularly those involved with complex land-atmosphere feedbacks, vegetation growth, and energy balances. Uncertainty persists despite using high resolution topography and/or detailed land use data. Thus, a good hydrologic model can produce right answers for wrong reasons. In this study, we develop an efficient approach for multi-variable assimilation of remotely sensed earth observations (EOs) into a hydrologic model and apply it in the 1700 km2 Pipestem Creek watershed in the Prairie Pothole Region of North Dakota, USA. Our goal is to employ EOs, specifically Leaf Area Index (LAI) and Potential Evapotranspiration (PET), as surrogates for the aforementioned processes without overruling the model's built-in physical/semi-empirical process conceptualizations. To do this, we modified the source code of an already-improved version of the Soil and Water Assessment Tool (SWAT) for wetland hydrology (Evenson et al. 2016 HP 30(22):4168) to directly assimilate remotely-sensed LAI and PET (obtained from the 500 m and 1 km Moderate Resolution Imaging Spectroradiometer (MODIS) gridded products, respectively) into each model Hydrologic Response Unit (HRU). Two configurations of the model, one with and one without EO assimilation, are calibrated against streamflow observations at the watershed outlet. Spatio-temporal changes in the HRU-level water balance, based on calibrated outputs, are evaluated using MODIS Actual Evapotranspiration (AET) as a reference. It is expected that the model configuration having remotely sensed LAI and PET, will simulate more realistic land-atmosphere feedbacks, vegetation growth and energy balance. As a result, this will decrease simulated

Measurements of reduced corkscrew motion on the ETA-II linear induction accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, S.L.; Brand, H.R.; Chambers, F.W.

1991-05-01

The ETA-II linear induction accelerator is used to drive a microwave free electron laser (FEL). Corkscrew motion, which previously limited performance, has been reduced by: (1) an improved pulse distribution system which reduces energy sweep, (2) improved magnetic alignment achieved with a stretched wire alignment technique (SWAT) and (3) a unique magnetic tuning algorithm. Experiments have been carried out on a 20-cell version of ETA-II operating at 1500 A and 2.7 MeV. The measured transverse beam motion is less than 0.5 mm for 40 ns of the pulse, an improvement of a factor of 2 to 3 over previous results.more » Details of the computerized tuning procedure, estimates of the corkscrew phase, and relevance of these results to future FEL experiments are presented. 11 refs.« less

Measuring forest evapotranspiration--theory and problems

Treesearch

Anthony C. Federer; Anthony C. Federer

1970-01-01

A satisfactory general method of measuring forest evapotranspiration has yet to be developed. Many procedures have been tried, but only the soil-water budget method and the micrometeorological methods offer any degree of success. This paper is a discussion of these procedures and the problems that arise in applying them. It is designed as a reference for scientists and...

Measurements of J/{psi} and {psi}(2S) decays into {lambda}{lambda}{pi}{sup 0} and {lambda}{lambda}{eta}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ablikim, M.; Bai, J. Z.; Cai, X.

2007-11-01

Using 58x10{sup 6} J/{psi} and 14x10{sup 6} {psi}(2S) events collected by the BESII detector at the BEPC, branching fractions or upper limits for the decays J/{psi} and {psi}(2S){yields}{lambda}{lambda}{pi}{sup 0} and {lambda}{lambda}{eta} are measured. For the isospin violating decays, the upper limits are determined to be B(J/{psi}{yields}{lambda}{lambda}{pi}{sup 0})<6.4x10{sup -5} and B[{psi}(2S){yields}{lambda}{lambda}{pi}{sup 0}]<4.9x10{sup -5} at the 90% confidence level. The isospin conserving process J/{psi}{yields}{lambda}{lambda}{eta} is observed for the first time, and its branching fraction is measured to be B(J/{psi}{yields}{lambda}{lambda}{eta})=(2.62{+-}0.60{+-}0.44)x10{sup -4}, where the first error is statistical and the second one is systematic. No {lambda}{lambda}{eta} signal is observed in {psi}(2S) decays, and B[{psi}(2S){yields}{lambda}{lambda}{eta}]<1.2x10{supmore » -4} is set at the 90% confidence level. Branching fractions of J/{psi} decays into {sigma}{sup +}{pi}{sup -}{lambda} and {sigma}{sup -}{pi}{sup +}{lambda} are also reported, and the sum of these branching fractions is determined to be B(J/{psi}{yields}{sigma}{sup +}{pi}{sup -}{lambda}+c.c.)=(1.52{+-}0.08{+-}0.16)x10{sup -3}.« less

A review of approaches for evapotranspiration partitioning

USDA-ARS?s Scientific Manuscript database

Partitioning of evapotranspiration (ET) into evaporation from the soil surface (E) and transpiration (T) is challenging but important in order to assess biomass production and the allocation of increasingly scarce water resources. Generally T is the desired component with the water being used to enh...

Calculation of evapotranspiration: Recursive and explicit methods

USDA-ARS?s Scientific Manuscript database

Crop yield is proportional to crop evapotranspiration (ETc) and it is important to calculate ETc correctly. Methods to calculate ETc have combined empirical and theoretical approaches. The combination method was used to calculate potential ETp. It is a combination method because it combined the ener...

Evapotranspiration from selected fallowed agricultural fields on the Tule Lake National Wildlife Refuge, California, during May to October 2000

USGS Publications Warehouse

Bidlake, W.R.

2002-01-01

An investigation of evapotranspiration, vegetation quantity and composition, and depth to the water table below the land surface was made at three sites in two fallowed agricultural lots on the 15,800-hectare Tule Lake National Wildlife Refuge in northern California during the 2000 growing season. All three sites had been farmed during 1999, but were not irrigated since the 1999 growing season. Vegetation at the lot C1B and lot 6 stubble sites included weedy species and small grain plants. The lot 6 cover crop site supported a crop of cereal rye that had been planted during the previous winter. Percentage of coverage by live vegetation ranged from 0 to 43.2 percent at the lot C1B site, from approximately 0 to 63.2 percent at the lot 6 stubble site, and it was estimated to range from 0 to greater than 90 percent at the lot 6 cover crop site. Evapotranspiration was measured using the Bowen ratio energy balance technique and it was estimated using a model that was based on the Priestley-Taylor equation and a model that was based on reference evapotranspiration with grass as the reference crop. Total evapotranspiration during May to October varied little among the three evapotranspiration measurement sites, although the timing of evapotranspiration losses did vary among the sites. Total evapotranspiration from the lot C1B site was 426 millimeters, total evapotranspiration from the lot 6 stubble site was 444 millimeters, and total evapotranspiration from the lot 6 cover crop site was 435 millimeters. The months of May to July accounted for approximately 78 percent of the total evapotranspiration from the lot C1B site, approximately 63 percent of the evapotranspiration from the lot 6 stubble site, and approximately 86 percent of the total evapotranspiration from the lot 6 cover crop site. Estimated growing season precipitation accounted for 16 percent of the growing-season evapotranspiration at the lot C1B site and for 17 percent of the growing-season evapotranspiration

Evapotranspiration and canopy resistance at an undeveloped prairie in a humid subtropical climate

USGS Publications Warehouse

Bidlake, W.R.

2002-01-01

Reliable estimates of evapotranspiration from areas of wildland vegetation are needed for many types of water-resource investigations. However, little is known about surface fluxes from many areally important vegetation types, and relatively few comparisons have been made to examine how well evapotranspiration models can predict evapotranspiration for soil-, climate-, or vegetation-types that differ from those under which the models have been calibrated. In this investigation at a prairie site in west-central Florida, latent heat flux (??E) computed from the energy balance and alternatively by eddy covariance during a 15-month period differed by 4 percent and 7 percent on hourly and daily time scales, respectively. Annual evapotranspiration computed from the energy balance and by eddy covariance were 978 and 944 mm, respectively. An hourly Penman-Monteith (PM) evapotranspiration model with stomatal control predicated on water-vapor-pressure deficit at canopy level, incoming solar radiation intensity, and soil water deficit was developed and calibrated using surface fluxes from eddy covariance. Model-predicted ??E agreed closely with ??E computed from the energy balance except when moisture from dew or precipitation covered vegetation surfaces. Finally, an hourly PM model developed for an Amazonian pasture predicted ??E for the Florida prairie with unexpected reliability. Additional comparisons of PM-type models that have been developed for differing types of short vegetation could aid in assessing interchangeability of such models.

A parabolic function to modify Thornthwaite estimates of potential evapotranspiration for the eastern United States

USGS Publications Warehouse

McCabe, G.J.

1989-01-01

Errors of the Thornthwaite model can be analyzed using adjusted pan evaporation as an index of potential evapotranspiration. An examination of ratios of adjusted pan evaporation to Thornthwaite potential evapotranspiration indicates that the ratios are highest in the winter and lowest during summer months. This trend suggests a parabolic pattern. In this study a parabolic function is used to adjust Thornthwaite estimates of potential evapotranspiration. Forty locations east of the Rocky Mountains are analyzed. -from Author

Predominant role of DNA polymerase eta and p53-dependent translesion synthesis in the survival of ultraviolet-irradiated human cells.

PubMed

Lerner, Leticia K; Francisco, Guilherme; Soltys, Daniela T; Rocha, Clarissa R R; Quinet, Annabel; Vessoni, Alexandre T; Castro, Ligia P; David, Taynah I P; Bustos, Silvina O; Strauss, Bryan E; Gottifredi, Vanesa; Stary, Anne; Sarasin, Alain; Chammas, Roger; Menck, Carlos F M

2017-02-17

Genome lesions trigger biological responses that help cells manage damaged DNA, improving cell survival. Pol eta is a translesion synthesis (TLS) polymerase that bypasses lesions that block replicative polymerases, avoiding continued stalling of replication forks, which could lead to cell death. p53 also plays an important role in preventing cell death after ultraviolet (UV) light exposure. Intriguingly, we show that p53 does so by favoring translesion DNA synthesis by pol eta. In fact, the p53-dependent induction of pol eta in normal and DNA repair-deficient XP-C human cells after UV exposure has a protective effect on cell survival after challenging UV exposures, which was absent in p53- and Pol H-silenced cells. Viability increase was associated with improved elongation of nascent DNA, indicating the protective effect was due to more efficient lesion bypass by pol eta. This protection was observed in cells proficient or deficient in nucleotide excision repair, suggesting that, from a cell survival perspective, proper bypass of DNA damage can be as relevant as removal. These results indicate p53 controls the induction of pol eta in DNA damaged human cells, resulting in improved TLS and enhancing cell tolerance to DNA damage, which parallels SOS responses in bacteria. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Variability in understory evapotranspiration with overstory density in Siberian larch forests

NASA Astrophysics Data System (ADS)

Tobio, A.; Loranty, M. M.; Kropp, H.; Pena, H., III; Alexander, H. D.; Natali, S.; Kholodov, A. L.

2016-12-01

Arctic ecosystems are changing rapidly in response to amplified rates of climate change. Increased vegetation productivity, altered ecosystem carbon and hydrologic cycling, and increased wildfire severity are among the key responses to changing permafrost and climate conditions. Boreal larch forests in northeastern Siberia are a critical but understudied ecosystem affected by these modifications. Understory vegetation in these ecosystems, which typically have low canopy cover, may account for half of all water fluxes. Despite the potential importance of the understory for ecosystem water exchange, there has been relatively little research examining variability in understory evapotranspiration in boreal larch forests. In particular, the water balance of understory shrubs and mosses is largely undefined and could provide insight on how understory vegetation and our changing climate interact. This is especially important because both observed increases in vegetation productivity and wildfire severity could lead to increases in forests density, altering the proportional contributions of over- and understory vegetation to whole ecosystem evapotranspiration. In order to better understand variability in understory evapotranspiration we measured in larch forests with differing overstory density and permafrost conditions that likely vary as a consequence of fire severity. We used the static chamber technique to measure fluxes across a range of understory vegetation types and environmental conditions. In general, we found that the understory vegetation in low density stands transpires more than that in high density stands. This tends to be correlated with a larger amount of aboveground biomass in the low density stands, and an increase in solar radiation, due to less shading by overstory trees. These results will help us to better understand water balances, evapotranspiration variability, and productivity changes associated with climate on understory vegetation. Additionally

Global fields of soil moisture and land surface evapotranspiration derived from observed precipitation and surface air temperature

NASA Technical Reports Server (NTRS)

Mintz, Y.; Walker, G. K.

1993-01-01

The global fields of normal monthly soil moisture and land surface evapotranspiration are derived with a simple water budget model that has precipitation and potential evapotranspiration as inputs. The precipitation is observed and the potential evapotranspiration is derived from the observed surface air temperature with the empirical regression equation of Thornthwaite (1954). It is shown that at locations where the net surface radiation flux has been measured, the potential evapotranspiration given by the Thornthwaite equation is in good agreement with those obtained with the radiation-based formulations of Priestley and Taylor (1972), Penman (1948), and Budyko (1956-1974), and this provides the justification for the use of the Thornthwaite equation. After deriving the global fields of soil moisture and evapotranspiration, the assumption is made that the potential evapotranspiration given by the Thornthwaite equation and by the Priestley-Taylor equation will everywhere be about the same; the inverse of the Priestley-Taylor equation is used to obtain the normal monthly global fields of net surface radiation flux minus ground heat storage. This and the derived evapotranspiration are then used in the equation for energy conservation at the surface of the earth to obtain the global fields of normal monthly sensible heat flux from the land surface to the atmosphere.

Evapotranspiration and water balance in a hot pepper (Capsicum frutescens L.) field during a dry season in the tropics

NASA Astrophysics Data System (ADS)

Laban, S.; Oue, H.; Rampisela, D. A.

2018-05-01

Evapotranspiration and water balance in a hot pepper (Capsicum frutescens L.) field during the 2nd dry season were analyzed in this study. Actual evapotranspiration (ET) was estimated by Bowen Ratio Energy Budget (BREB) method, potential evaporation (EP) was calculated by Penman method, and irrigation volume of water was measured manually. Meteorological instruments were installed in the experimental field during hot pepper cultivation. Leaf area index increased during the growing stages where the highest LAI of 1.65 in the generative stage. The daily average of ET was 1.94 and EP was 6.71 mm resulting in low Kc. The Kc values were significantly different between stage to stage under T-test analysis (α = 0.05). Moreover, Kc in every stage could be related to soil water content (SWC) in logarithmic function. Totally, ET during hot pepper cultivation was 179.19 mm, while rainfall was 180.0 mm and irrigation water was 27.42 mm. However, there was a water shortages during vegetative and generative stages. This study suggested that consumptive water of hot pepper was complimented by soil and groundwater under the condition of water shortages in the vegetative and generative stages during the 2nd dry season.

Can the complementary relationship between actual and potential evaporation be used to quantify heatwaves?

NASA Astrophysics Data System (ADS)

Aminzadeh, Milad; Or, Dani

2017-04-01

Extreme climate events such as heatwaves with prolonged periods of high air temperatures have large environmental, social, and economic impacts ranging from crop failure to health and desiccation damages. Periods of low precipitation with high temperatures decrease soil moisture storage and thus affect surface energy partitioning. The heuristic concepts in the basis of the Complementary Relationship (CR) suggest that a fraction of radiative energy not used for evaporation contributes to increased sensible heat flux thus heats near-surface atmosphere. We have recently generalized the CR framework for spatially heterogeneous landscapes thereby enable prediction of actual evapotranspiration (ET) from routine atmospheric measurements. Capitalizing on the coupling between moisture availability, actual ET and sensible heat flux we propose using the CR to predict conditions conducive to rapid increase in regional sensible heat flux associated with the onset of extreme heatwaves. The proposed framework is evaluated using satellite surface temperature and FLUXNET data with newly derived metrics for the onset of heatwaves. The concepts could be extended to obtain new insights into the dynamics of more persistent climate extremes such as regional droughts.

Androgens influence microvascular dilation in PCOS through ET-A and ET-B receptors

PubMed Central

Wenner, Megan M.; Taylor, Hugh S.

2013-01-01

Hyperandrogenism and vascular dysfunction often coexist in women with polycystic ovary syndrome (PCOS). We hypothesized that testosterone compromises cutaneous microvascular dilation in women with PCOS via the endothelin-1 ET-B subtype receptor. To control and isolate testosterone's effects on microvascular dilation, we administered a gonadotropin-releasing hormone antagonist (GnRHant) for 11 days in obese, otherwise healthy women [controls, 22.0 (4) yr, 36.0 (3.2) kg/m2] or women with PCOS [23 (4) yr, 35.4 (1.3) kg/m2], adding testosterone (T; 2.5 mg/day) on days 8–11. Using laser Doppler flowmetry and cutaneous microdialysis, we measured changes in skin microcirculatory responsiveness (ΔCVC) to local heating while perfusing ET-A (BQ-123) and ET-B (BQ-788) receptor antagonists under three experimental conditions: baseline (BL; prehormone intervention), GnRHant (day 4 of administration), and T administration. At BL, ET-A receptor inhibition enhanced heat-induced vasodilation in both groups [ΔCVC control 2.03 (0.65), PCOS 2.10 (0.25), AU/mmHg, P < 0.05]; ET-B receptor inhibition reduced vasodilation in controls only [ΔCVC 0.98 (0.39), 1.41 (0.45) AU/mmHg for controls, PCOS] compared with saline [ΔCVC controls 1.27 (0.48), PCOS 1.31 (0.13) AU/mmHg]. GnRHant enhanced vasodilation in PCOS [saline ΔCVC 1.69 (0.23) AU/mmHg vs. BL, P < 0.05] and abolished the ET-A effect in both groups, a response reasserted with T in controls. ET-B receptor inhibition reduced heat-induced vasodilation in both groups during GnRHant and T [ΔCVC, controls: 0.95 (0.21) vs. 0.51 (13); PCOS: 1.27 (0.23) vs. 0.84 (0.27); for GnRHant vs. T, P < 0.05]. These data demonstrate that androgen suppression improves microvascular dilation in PCOS via ET-A and ET-B receptors. PMID:23921139

Statistical Analysis and ETAS Modeling of Seismicity Induced by Production of Geothermal Energy from Hydrothermal Systems

NASA Astrophysics Data System (ADS)

Dinske, C.; Langenbruch, C.; Shapiro, S. A.

2017-12-01

We investigate seismicity related to hydrothermal systems in Germany and Italy, focussing on temporal changes of seismicity rates. Our analysis was motivated by numerical simulations The modeling of stress changes caused by the injection and production of fluid revealed that seismicity rates decrease on a long-term perspective which is not observed in the considered case studies. We analyze the waiting time distributions of the seismic events in both time domain (inter event times) and fluid volume domain (inter event volume). We find clear indications that the observed seismicity comprises two components: (1) seismicity that is directly triggered by production and re-injection of fluid, i.e. induced events, and (2) seismicity that is triggered by earthquake interactions, i.e. aftershock triggering. In order to better constrain our numerical simulations using the observed induced seismicity we apply catalog declustering to seperate the two components. We use the magnitude-dependent space-time windowing approach introduced by Gardner and Knopoff (1974) and test several published algorithms to calculate the space-time windows. After declustering, we conclude that the different hydrothermal reservoirs show a comparable seismic response to the circulation of fluid and additional triggering by earthquake interactions. The declustered catalogs contain approximately 50 per cent of the number of events in the original catalogs. We then perform ETAS (Epidemic Type Aftershock; Ogata, 1986, 1988) modeling for two reasons. First, we want to know whether the different reservoirs are also comparable regarding earthquake interaction patterns. Second, if we identify systematic patterns, ETAS modeling can contribute to forecast seismicity during production of geothermal energy. We find that stationary ETAS models cannot accurately capture real seismicity rate changes. One reason for this finding is given by the rate of observed induced events which is not constant over time. Hence

Amazon river basin evapotranspiration and its influence on the rainfall in southern Brazil

NASA Astrophysics Data System (ADS)

Folegatti, M. V.; Wolff, W.

2017-12-01

Amazon river basin (ARB) presents a positive water balance, i.e. the precipitation is higher than evapotranspiration. Regarding the regional circulation, ARB evapotranspiration represents an important source of humidity for the South of Brazil. Thus, the aim of this work is to answer the question: how much is the correlation between ARB evapotranspiration and rainfall in South of Brazil? The shapefiles data of ARB and countries/states boundary were obtained through the Oak Ridge National Laboratory (ORNL) and Instituto Brasileiro de Geografia e Estatística (IBGE), respectively. According to rasters data, the precipitation was obtained from study of Numerical Terradynamic Simulation Group (NTSG) for images of Moderate Resolution Imaging Spectroradiometer (MODIS), under code MOD16A2, whereas rasters data for evapotranspiration were obtained from National Aeronautics and Space Administration (NASA) by Tropical Rainfall Measuring Mission Multi-Satellite Precipitation Analysis (TMPA), under code 3B43_V7. The products MOD16A2 and 3B43_V7 have a respective spatial resolution of 0.5º and 0.25º, and a monthly temporal resolution from January/2000 to December/2014. For ARB and South region of Brazil was calculated the mean evapotranspiration and mean precipitation through the pixels within of the respective polygons. To answer the question of this work was performed the cross-correlation analysis between these time series. We observed the highest value for the lag that corresponds the begin of spring (October), being 0.3 approximately. As a result, the mean precipitation on South region of Brazil during spring and summer was in the order of 15% to 30 %, explained by ARB evapotranspiration. For this reason, the maintenance of ARB is extremely important for water resource grant in South of Brazil.

Harmonizing multiple methods for reconstructing historical potential and reference evapotranspiration

USGS Publications Warehouse

Belaineh, Getachew; Sumner, David; Carter, Edward; Clapp, David

2013-01-01

Potential evapotranspiration (PET) and reference evapotranspiration (RET) data are usually critical components of hydrologic analysis. Many different equations are available to estimate PET and RET. Most of these equations, such as the Priestley-Taylor and Penman- Monteith methods, rely on detailed meteorological data collected at ground-based weather stations. Few weather stations collect enough data to estimate PET or RET using one of the more complex evapotranspiration equations. Currently, satellite data integrated with ground meteorological data are used with one of these evapotranspiration equations to accurately estimate PET and RET. However, earlier than the last few decades, historical reconstructions of PET and RET needed for many hydrologic analyses are limited by the paucity of satellite data and of some types of ground data. Air temperature stands out as the most generally available meteorological ground data type over the last century. Temperature-based approaches used with readily available historical temperature data offer the potential for long period-of-record PET and RET historical reconstructions. A challenge is the inconsistency between the more accurate, but more data intensive, methods appropriate for more recent periods and the less accurate, but less data intensive, methods appropriate to the more distant past. In this study, multiple methods are harmonized in a seamless reconstruction of historical PET and RET by quantifying and eliminating the biases of the simple Hargreaves-Samani method relative to the more complex and accurate Priestley-Taylor and Penman-Monteith methods. This harmonization process is used to generate long-term, internally consistent, spatiotemporal databases of PET and RET.

[Energy balance and evapotranspiration in broad-leaved Korean pine forest in Changbai Mountains].

PubMed

Zhang, Xin-jian; Yuan, Feng-hui; Chen, Ni-na; Deng, Jun-li; Yu, Xiao-zhou; Sheng, Xue-jiao

2011-03-01

Based on the continuous measurements of an open-path eddy covariance system, this paper analyzed the characteristics of energy balance components and evapotranspiration in a broad-leaved Korean pine forest in Changbai Mountains in 2008, as well as the differences of energy balance components and evapotranspiration between growth season and dormant season. For the test forest, the year-round energy balance closure was 72%, being at a medium level, compared to the other studies in the Fluxnet community. The energy balance components had significant differences in their diurnal and seasonal variations. In growth season, turbulent energy exchange was dominated by upward latent heat flux, accounting for 66% of available energy; while in dormant season, the turbulent energy exchange was dominated by upward sensible heat flux, accounting for 63% of available energy. The accumulated annual evapotranspiration in the study site in 2008 was 484.7 mm, occupying 87% of the precipitation at the same time period (558.9 mm), which demonstrated that evapotranspiration was the main water loss item in temperate forests of northern China.

Evapotranspiration-based irrigation scheduling of lettuce and broccoli

USDA-ARS?s Scientific Manuscript database

Estimation of crop evapotranspiration supports efficient irrigation water management, which in turn supports water conservation, mitigation of groundwater depletion/degradation, energy savings, and crop quality maintenance. Past research in California has revealed strong relationships between fract...

The Eta Carinae Homunculus in Full 3D with X-Shooter and Shape

NASA Technical Reports Server (NTRS)

Steffen, Wolfgang; Teodoro, Mairan; Madura, Thomas I.; Groh, Jose H.; Gull, Theodore R.; Mehner, Andrea; Corcoran, Michael F.; Damineli, Augusto; Hamaguchi, Kenji

2014-01-01

Massive stars like Eta Carinae are extremely rare in comparison to stars such as the Sun, and currently we know of only a handful of stars with masses of more than 100 solar mass in the Milky Way. Such massive stars were much more frequent in the early history of the Universe and had a huge impact on its evolution. Even among this elite club, Eta Car is outstanding, in particular because of its giant eruption around 1840 that produced the beautiful bipolar nebula now known as the Homunculus. In this study, we used detailed spatio-kinematic information obtained from X-shooter spectra to reconstruct the 3D structure of the Homunculus. The small-scale features suggest that the central massive binary played a significant role in shaping the Homunculus.

The eta Carinae Treasury Project and the HST/STIS

NASA Technical Reports Server (NTRS)

Martin, John C.; Davidson, Kris

2006-01-01

The HST Eta Carinae Treasury Project made extensive use of the HST/STIS from 1998 to the time of its failure in 2004. As one of the most prolific users of that instrument, the Treasury Project used the cross-dispersed spatial resolution of the STIS as few projects did. We present several enhancements to the existing STIS data reduction methods that are applicable to non-Treasury Project data in the STIS archive.

Selective up-regulation of protein kinase C eta in phorbol ester-sensitive versus -resistant EL4 mouse thymoma cells.

PubMed

Resnick, M S; Luo, X; Vinton, E G; Sando, J J

1997-06-01

Stimulation of sensitive EL4 mouse thymoma cells (s-EL4) with phorbol esters results in production of interleukin 2 (IL-2), adherence to a plastic substrate, and growth inhibition, whereas a phorbol ester-resistant variant (r-EL4) fails to respond. Previous studies revealed substantially decreased expression of protein kinase C (PKC) epsilon in the r-EL4 versus s-EL4 cells. This work has been extended to examine the more recently described PKC isozymes. Western and Northern analyses revealed a marked decrease in PKC eta and theta in r-EL4 as compared to s-EL4 cells. Treatment of these lines with phorbol ester for 24 h resulted in down-regulation of all PKC isozymes examined except PKC eta, which was up-regulated in the s-EL4 cells at the time of maximal IL-2 production. Two newly isolated EL4 clones, resistant to phorbol ester-induced growth inhibition but still exhibiting the phorbol ester-induced adherence and IL-2 production, both expressed PKC eta and theta. Collectively, these observations suggest a dissociation of growth inhibition from adherence and IL-2 production pathways and a potential role for PKC eta in the latter.

FIELD EVALUATION OF EVAPO-TRANSPIRATION (ET) CAPS

EPA Science Inventory

A field study was conducted to assess the ability of landfill covers to control percolation into the waste. Performance of one conventional cover was compared to that of two evapotranspiration (ET) tree covers, using large (7 x 14 m) lined lysimeters at the Leon County Solid W...

The complementary relationship in estimation of regional evapotranspiration: An enhanced Advection-Aridity model

Treesearch

Michael T. Hobbins; Jorge A. Ramirez; Thomas C. Brown

2001-01-01

Long-term monthly evapotranspiration estimates from Brutsaert and Stricker’s Advection-Aridity model were compared with independent estimates of evapotranspiration derived from long-term water balances for 139 undisturbed basins across the conterminous United States. On an average annual basis for the period 1962-1988 the original model, which uses a Penman wind...

Partitioning Evapotranspiration into Green and Blue Water Sources: Understanding Temporal Dynamics (2001-2015) and Spatial Variability in the Conterminous United States

NASA Astrophysics Data System (ADS)

Velpuri, N. M.; Senay, G. B.

2017-12-01

Information on how much of direct rain water (green water) and/or non-rain water (blue water) are being productively used by the crops/vegetation is critical for efficient water resources management. In this study, we developed a simple but robust methodology to partition actual evapotranspiration (ET) into green (rainfall-based) and blue (surface water/groundwater) sources. We combined two 1 km MODIS-based actual evapotranspiration datasets, one obtained from a root zone water balance model and another from an energy balance model, to partition annual ET into green water ET (GWET) and blue water ET (BWET). Time series maps of GWET and BWET were produced for the conterminous United States (CONUS) over 2001-2015 and spatial variability and dynamics of blue and green water ET were analyzed. Our results indicate that average green and blue water sources for all land cover types in CONUS account for nearly 70% and 30% of the total ET, respectively. The ET in the eastern US arises mostly from green water, and in the western US, it is mostly from blue water sources. Analysis of the BWET in the 16 selected irrigated areas in CONUS revealed interesting results. While the magnitude of the BWET showed a gradual decline from west to east, the increase in coefficient of variation from west to east confirmed greater use of supplemental irrigation in the central and eastern US. We also established relationships between hydro-climatic regions and their blue water requirements. This study provides insights into the relative contributions and the spatiotemporal dynamics of GWET and BWET, which could lead to improved water resources management.

78 FR 32460 - Comment Request for Information Collection for ETA Form 232, Domestic Agricultural In-Season Wage...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-30

...The Department of Labor (Department), as part of its continuing effort to reduce paperwork and respondent burden, conducts a preclearance consultation program to provide the public and Federal agencies with an opportunity to comment on proposed and/or continuing collections of information in accordance with the Paperwork Reduction Act of 1995 [44 U.S.C. 3506(c)(2)(A)]. This program helps ensure that requested data can be provided in the desired format, reporting burden (time and financial resources) is minimized, collection instruments are clearly understood, and the impact of collection requirements on respondents can be properly assessed. Currently, ETA is soliciting comments concerning the collection of data about ETA Form 232, Domestic Agricultural In-Season Wage Report and ETA Form 232-A, Wage Survey Interview Record, OMB Control No. 1205- 0017, both of which expire July 31, 2013. These forms are used by the State Workforce Agencies to collect wage information from agricultural employers.

The Time Evolution of Eta Carinae's Colliding Winds

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Madura, T. I.; Grobe, J. H.; Corcoran, M. F.

2011-01-01

We report new HST/STIS observations that map the high-ionization forbidden line emission in the inner arc second of Eta Car, the first that fully image the extended wind-wind interaction region of the massive colliding wind binary. These observations were obtained after the 2009.0 periastron at orbital phases 0.084, 0.163, and 0.323 of the 5.54-year spectroscopic cycle. We analyze the variations in brightness and morphology of the emission, and find that blue-shifted emission (-400 to -200 km/s is symmetric and elongated along the northeast-southwest axis, while the red-shifted emission (+ 100 to +200 km/s) is asymmetric and extends to the north-northwest. Comparison to synthetic images generated from a 3-D dynamical model strengthens the 3-D orbital orientation found by Madura et al. (2011), with an inclination i = 138 deg, argument of periapsis w = 270 deg, and an orbital axis that is aligned at the same P A on the sky as the symmetry axis of the Homunculus, 312 deg. We discuss the potential that these and future mappings have for constraining the stellar parameters of the companion star and the long-term variability of the system. Plain-Language Abstract: With HST, we resolved the interacting winds of the binary, Eta Carinae. With a 3-D model, we find the binary orbit axis is aligned to the Homunculus axis. This suggests a connection between the binary and Homunculus ejection mechanism.

The ep -->e'p eta reaction at and above the S11(1535) baryon resonance.

PubMed

Thompson, R; Dytman, S; Kim, K Y; Mueller, J; Adams, G S; Amaryan, M J; Anciant, E; Anghinolfi, M; Asavapibhop, B; Auger, T; Audit, G; Avakian, H; Barrow, S; Battaglieri, M; Beard, K; Bektasoglu, M; Bertozzi, W; Bianchi, N; Biselli, A; Boiarinov, S; Bonner, B E; Briscoe, W J; Brooks, W; Burkert, V D; Calarco, J R; Capitani, G; Carman, D S; Carnahan, B; Cole, P L; Coleman, A; Connelly, J; Cords, D; Corvisiero, P; Crabb, D; Crannell, H; Cummings, J; Day, D; Degtyarenko, P V; Demirchyan, R A; Dennis, L C; Deppman, A; De Sanctis, E; De Vita, R; Dhuga, K S; Djalali, C; Dodge, G E; Doughty, D; Dragovitsch, P; Dugger, M; Eckhause, M; Efremenko, Y V; Egiyan, H; Egiyan, K S; Elouadrhiri, L; Farhi, L; Feuerbach, R J; Ficenec, J; Fissum, K; Freyberger, A; Funsten, H; Gai, M; Gavrilov, V B; Gilfoyle, G P; Giovanetti, K; Gilad, S; Girard, P; Griffioen, K A; Guidal, M; Guillo, M; Gyurjyan, V; Hancock, D; Hardie, J; Heddle, D; Heisenberg, J; Hersman, F W; Hicks, K; Hicks, R S; Holtrop, M; Hyde-Wright, C E; Ito, M M; Jenkins, D; Joo, K; Kane, J; Khandaker, M; Kim, W; Klein, A; Klein, F J; Klusman, M; Kossov, M; Kuhn, S E; Kuang, Y; Laget, J M; Lawrence, D; Leskin, G A; Longhi, A; Loukachine, K; Lucas, M; Magahiz, R; Major, R W; Manak, J J; Marchand, C; Matthews, S K; McAleer, S; McCarthy, J; McNabb, J W; Mecking, B A; Mestayer, M D; Meyer, C A; Minehart, R; Mirazita, M; Miskimen, R; Muccifora, V; Mutchler, G S; Napolitano, J; Niyazov, R A; Ohandjanyan, M S; O'Brien, J T; Opper, A; Patois, Y; Peterson, G A; Philips, S; Pivnyuk, N; Pocanic, D; Pogorelko, O; Polli, E; Preedom, B M; Price, J W; Qin, L M; Raue, B A; Reolon, A R; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rossi, P; Roudot, F; Rowntree, D; Rubin, P D; Salgado, C W; Sanzone, M; Sapunenko, V; Sarty, A; Sargsyan, M; Schumacher, R A; Shafi, A; Sharabian, Y G; Shaw, J; Shuvalov, S M; Skabelin, A; Smith, T; Smith, C; Smith, E S; Sober, D I; Spraker, M; Stepanyan, S; Stoler, P; Taiuti, M; Taylor, S; Tedeschi, D; Tung, T Y; Vineyard, M F; Vlassov, A; Weller, H; Weinstein, L B; Welsh, R; Weygand, D P; Whisnant, S; Witkowski, M; Wolin, E; Yegneswaran, A; Yun, J; Zhou, Z; Zhao, J

2001-02-26

New cross sections for the reaction e p-->e p eta are reported for total center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q2 = 0.25--1.5 (GeV/c)(2). This large kinematic range allows extraction of important new information about response functions, photocouplings, and eta N coupling strengths of baryon resonances. Newly observed structure at W approximately 1.65 GeV is shown to come from interference between S and P waves and can be interpreted with known resonances. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance.

Satellite-based monitoring of cotton evapotranspiration

NASA Astrophysics Data System (ADS)

Dalezios, Nicolas; Dercas, Nicholas; Tarquis, Ana Maria

2016-04-01

Water for agricultural use represents the largest share among all water uses. Vulnerability in agriculture is influenced, among others, by extended periods of water shortage in regions exposed to droughts. Advanced technological approaches and methodologies, including remote sensing, are increasingly incorporated for the assessment of irrigation water requirements. In this paper, remote sensing techniques are integrated for the estimation and monitoring of crop evapotranspiration ETc. The study area is Thessaly central Greece, which is a drought-prone agricultural region. Cotton fields in a small agricultural sub-catchment in Thessaly are used as an experimental site. Daily meteorological data and weekly field data are recorded throughout seven (2004-2010) growing seasons for the computation of reference evapotranspiration ETo, crop coefficient Kc and cotton crop ETc based on conventional data. Satellite data (Landsat TM) for the corresponding period are processed to estimate cotton crop coefficient Kc and cotton crop ETc and delineate its spatiotemporal variability. The methodology is applied for monitoring Kc and ETc during the growing season in the selected sub-catchment. Several error statistics are used showing very good agreement with ground-truth observations.

THE EMISSION PROCESSING SYSTEM FOR THE ETA/CMAQ AIR QUALITY FORECAST SYSTEM

EPA Science Inventory

NOAA and EPA have created an Air Quality Forecast (AQF) system. This AQF system links an adaptation of the EPA's Community Multiscale Air Quality Model with the 12 kilometer ETA model running operationally at NOAA's National Center for Environmental Predication (NCEP). One of th...

A comparison of methods for determining field evapotranspiration: photosynthesis system, sap flow, and eddy covariance

NASA Astrophysics Data System (ADS)

Zhang, Z.; Tian, F.; Hu, H.; Yang, P.

2014-03-01

A multi-scale, multi-technique study was conducted to measure evapotranspiration and its components in a cotton field under mulched drip irrigation conditions in northwestern China. Three measurement techniques at different scales were used: a photosynthesis system (leaf scale), sap flow (plant scale), and eddy covariance (field scale). The experiment was conducted from July to September 2012. To upscale the evapotranspiration from the leaf to plant scale, an approach that incorporated the canopy structure and the relationships between sunlit and shaded leaves was proposed. To upscale the evapotranspiration from the plant to field scale, an approach based on the transpiration per unit leaf area was adopted and modified to incorporate the temporal variability in the relationship between leaf areas and stem diameter. At the plant scale, the estimate of the transpiration based on the photosynthesis system with upscaling was slightly higher (18%) than that obtained by sap flow. At the field scale, the estimates of transpiration derived from sap flow with upscaling and eddy covariance showed reasonable consistency during the cotton's open-boll growth stage, during which soil evaporation can be neglected. The results indicate that the proposed upscaling approaches are reasonable and valid. Based on the measurements and upscaling approaches, evapotranspiration components were analyzed for a cotton field under mulched drip irrigation. During the two analyzed sub-periods in July and August, evapotranspiration rates were 3.94 and 4.53 m day-1, respectively. The fraction of transpiration to evapotranspiration reached 87.1% before drip irrigation and 82.3% after irrigation. The high fraction of transpiration over evapotranspiration was principally due to the mulched film above the drip pipe, low soil water content in the inter-film zone, well-closed canopy, and high water requirement of the crop.

A comparison of methods for determining field evapotranspiration: photosynthesis system, sap flow, and eddy covariance

NASA Astrophysics Data System (ADS)

Zhang, Z.; Tian, F.; Hu, H. C.; Hu, H. P.

2013-11-01

A multi-scale, multi-technique study was conducted to measure evapotranspiration and its components in a cotton field under mulched drip irrigation conditions in northwestern China. Three measurement techniques at different scales were used: photosynthesis system (leaf scale), sap flow (plant scale), and eddy covariance (field scale). The experiment was conducted from July to September 2012. To upscale the evapotranspiration from the leaf to the plant scale, an approach that incorporated the canopy structure and the relationships between sunlit and shaded leaves was proposed. To upscale the evapotranspiration from the plant to the field scale, an approach based on the transpiration per unit leaf area was adopted and modified to incorporate the temporal variability in the relationships between leaf area and stem diameter. At the plant scale, the estimate of the transpiration based on the photosynthesis system with upscaling was slightly higher (18%) than that obtained by sap flow. At the field scale, the estimates of transpiration derived from sap flow with upscaling and eddy covariance shown reasonable consistency during the cotton open boll growth stage when soil evaporation can be neglected. The results indicate that the upscaling approaches are reasonable and valid. Based on the measurements and upscaling approaches, evapotranspiration components were analyzed under mulched drip irrigation. During the two analysis sub-periods in July and August, evapotranspiration rates were 3.94 and 4.53 mm day-1, respectively. The fraction of transpiration to evapotranspiration reached 87.1% before drip irrigation and 82.3% after irrigation. The high fraction of transpiration over evapotranspiration was principally due to the mulched film above drip pipe, low soil water content in the inter-film zone, well-closed canopy, and high water requirement of the crop.

Student Measurements of the Double Star Eta Cassiopeiae

NASA Astrophysics Data System (ADS)

Brewer, Mark; Cacace, Gabriel; Do, Vivian; Griffith, Nicholas; Malan, Alexandria; Paredes, Hanna; Peticolas, Brian; Stasiak, Kathryne

2016-10-01

The double star Eta Cassiopeiae was measured at Vanguard Preparatory School. Digital measurements were made with a 14-inch telescope equipped with a CCD camera. The plate scale was determined to be 0.50 arcseconds per pixel. The separations and position angles were determined to be 13.3 arcseconds and 340.4 degrees, by the use of astronomy software. Previous observations reported in the Washington Double Star Catalog were used as a comparison. The camera angle was found to be the ultimate issue in the skewed data gathered for the double star.

Eta Carinae: A Demanding Mistress

NASA Technical Reports Server (NTRS)

Gull, Theodore

2012-01-01

In the 1840's a southern star, Eta Argus, brightened to rival Sirius for nearly a decade, then faded. Today, we see the Homunculus, an hourglass figure with tutu, a dusty shell exceeding 12 solar masses expanding outward at 500 km/s. Many observers have systematically studied the massive binary total shrouded by interacting winds and its ejecta. More recently 3-D wind-wind collision models have begun to explain the extended structures resolved by Hubble Space Telescope. Now Herschel Space Observatory infrared scans are revealing wind interaction emissions and complex molecules left over from the dust that formed out of gas originally overabundant in nitrogen and greatly-depleted in oxygen and carbon. Many questions remain to be answered: What is the dust that formed in the 1840s event? What are the end states of the two massive companions ... SN, GRB, Hypernova? and When

Observation of Upsilon(2S)-->etaUpsilon(1S) and search for related transitions.

PubMed

He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Reed, J; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hunt, J M; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Ledoux, J; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Xavier, J V; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Libby, J; Martin, L; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; Mendez, H; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J

2008-11-07

We report the first observation of Upsilon(2S)-->etaUpsilon(1S), with a branching fraction B=(2.1(-0.6)+0.7(stat)+/-0.3(syst)) x 10(-4) and a statistical significance 5.3sigma. Data were acquired with the CLEO III detector at the CESR e+e(-) symmetric collider. This is the first process observed involving a b-quark spin flip. For related transitions, 90% confidence limits in units of 10(-4) are B(Upsilon(2S)-->pi0Upsilon(1S)) < 1.8, B(Upsilon(3S)-->etaUpsilon(1S)) < 1.8, B(Upsilon(3S)-->pi0Upsilon(1S)) < 0.7, and B(Upsilon(3S)-->pi0Upsilon(2S)) < 5.1.

Simple process-led algorithms for simulating habitats (SPLASH v.1.0): robust indices of radiation, evapotranspiration and plant-available moisture

NASA Astrophysics Data System (ADS)

Davis, Tyler W.; Prentice, I. Colin; Stocker, Benjamin D.; Thomas, Rebecca T.; Whitley, Rhys J.; Wang, Han; Evans, Bradley J.; Gallego-Sala, Angela V.; Sykes, Martin T.; Cramer, Wolfgang

2017-02-01

Bioclimatic indices for use in studies of ecosystem function, species distribution, and vegetation dynamics under changing climate scenarios depend on estimates of surface fluxes and other quantities, such as radiation, evapotranspiration and soil moisture, for which direct observations are sparse. These quantities can be derived indirectly from meteorological variables, such as near-surface air temperature, precipitation and cloudiness. Here we present a consolidated set of simple process-led algorithms for simulating habitats (SPLASH) allowing robust approximations of key quantities at ecologically relevant timescales. We specify equations, derivations, simplifications, and assumptions for the estimation of daily and monthly quantities of top-of-the-atmosphere solar radiation, net surface radiation, photosynthetic photon flux density, evapotranspiration (potential, equilibrium, and actual), condensation, soil moisture, and runoff, based on analysis of their relationship to fundamental climatic drivers. The climatic drivers include a minimum of three meteorological inputs: precipitation, air temperature, and fraction of bright sunshine hours. Indices, such as the moisture index, the climatic water deficit, and the Priestley-Taylor coefficient, are also defined. The SPLASH code is transcribed in C++, FORTRAN, Python, and R. A total of 1 year of results are presented at the local and global scales to exemplify the spatiotemporal patterns of daily and monthly model outputs along with comparisons to other model results.

RIPGIS-NET: a GIS tool for riparian groundwater evapotranspiration in MODFLOW.

PubMed

Ajami, Hoori; Maddock, Thomas; Meixner, Thomas; Hogan, James F; Guertin, D Phillip

2012-01-01

RIPGIS-NET, an Environmental System Research Institute (ESRI's) ArcGIS 9.2/9.3 custom application, was developed to derive parameters and visualize results of spatially explicit riparian groundwater evapotranspiration (ETg), evapotranspiration from saturated zone, in groundwater flow models for ecohydrology, riparian ecosystem management, and stream restoration. Specifically RIPGIS-NET works with riparian evapotranspiration (RIP-ET), a modeling package that works with the MODFLOW groundwater flow model. RIP-ET improves ETg simulations by using a set of eco-physiologically based ETg curves for plant functional subgroups (PFSGs), and separates ground evaporation and plant transpiration processes from the water table. The RIPGIS-NET program was developed in Visual Basic 2005, .NET framework 2.0, and runs in ArcMap 9.2 and 9.3 applications. RIPGIS-NET, a pre- and post-processor for RIP-ET, incorporates spatial variability of riparian vegetation and land surface elevation into ETg estimation in MODFLOW groundwater models. RIPGIS-NET derives RIP-ET input parameters including PFSG evapotranspiration curve parameters, fractional coverage areas of each PFSG in a MODFLOW cell, and average surface elevation per riparian vegetation polygon using a digital elevation model. RIPGIS-NET also provides visualization tools for modelers to create head maps, depth to water table (DTWT) maps, and plot DTWT for a PFSG in a polygon in the Geographic Information System based on MODFLOW simulation results. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

Linking precipitation, evapotranspiration and soil moisture content for the improvement of predictability over land

NASA Astrophysics Data System (ADS)

Catalano, Franco; Alessandri, Andrea; De Felice, Matteo

2013-04-01

Climate change scenarios are expected to show an intensification of the hydrological cycle together with modifications of evapotranspiration and soil moisture content. Evapotranspiration changes have been already evidenced for the end of the 20th century. The variance of evapotranspiration has been shown to be strongly related to the variance of precipitation over land. Nevertheless, the feedbacks between evapotranspiration, soil moisture and precipitation have not yet been completely understood at present-day. Furthermore, soil moisture reservoirs are associated to a memory and thus their proper initialization may have a strong influence on predictability. In particular, the linkage between precipitation and soil moisture is modulated by the effects on evapotranspiration. Therefore, the investigation of the coupling between these variables appear to be of primary importance for the improvement of predictability over the continents. The coupled manifold (CM) technique (Navarra and Tribbia 2005) is a method designed to separate the effects of the variability of two variables which are connected. This method has proved to be successful for the analysis of different climate fields, like precipitation, vegetation and sea surface temperature. In particular, the coupled variables reveal patterns that may be connected with specific phenomena, thus providing hints regarding potential predictability. In this study we applied the CM to recent observational datasets of precipitation (from CRU), evapotranspiration (from GIMMS and MODIS satellite-based estimates) and soil moisture content (from ESA) spanning a time period of 23 years (1984-2006) with a monthly frequency. Different data stratification (monthly, seasonal, summer JJA) have been employed to analyze the persistence of the patterns and their characteristical time scales and seasonality. The three variables considered show a significant coupling among each other. Interestingly, most of the signal of the

Spectrophotometric, colorimetric and visually detection of Pseudomonas aeruginosa ETA gene based gold nanoparticles DNA probe and endonuclease enzyme

NASA Astrophysics Data System (ADS)

Amini, Bahram; Kamali, Mehdi; Salouti, Mojtaba; Yaghmaei, Parichehreh

2018-06-01

Colorimetric DNA detection is preferred over other methods for clinical molecular diagnosis because it does not require expensive equipment. In the present study, the colorimetric method based on gold nanoparticles (GNPs) and endonuclease enzyme was used for the detection of P. aeruginosa ETA gene. Firstly, the primers and probe for P. aeruginosa exotoxin A (ETA) gene were designed and checked for specificity by the PCR method. Then, GNPs were synthesized using the citrate reduction method and conjugated with the prepared probe to develop the new nano-biosensor. Next, the extracted target DNA of the bacteria was added to GNP-probe complex to check its efficacy for P. aeruginosa ETA gene diagnosis. A decrease in absorbance was seen when GNP-probe-target DNA cleaved into the small fragments of BamHI endonuclease due to the weakened electrostatic interaction between GNPs and the shortened DNA. The right shift of the absorbance peak from 530 to 562 nm occurred after adding the endonuclease. It was measured using a UV-VIS absorption spectroscopy that indicates the existence of the P. aeruginosa ETA gene. Sensitivity was determined in the presence of different concentrations of target DNA of P. aeruginosa. The results obtained from the optimized conditions showed that the absorbance value has linear correlation with concentration of target DNA (R: 0.9850) in the range of 10-50 ng mL-1 with the limit detection of 9.899 ng mL-1. Thus, the specificity of the new method for detection of P. aeruginosa was established in comparison with other bacteria. Additionally, the designed assay was quantitatively applied to detect the P. aeruginosa ETA gene from 103 to 108 CFU mL-1 in real samples with a detection limit of 320 CFU mL-1.

Spectrophotometric, colorimetric and visually detection of Pseudomonas aeruginosa ETA gene based gold nanoparticles DNA probe and endonuclease enzyme.

PubMed

Amini, Bahram; Kamali, Mehdi; Salouti, Mojtaba; Yaghmaei, Parichehreh

2018-06-15

Colorimetric DNA detection is preferred over other methods for clinical molecular diagnosis because it does not require expensive equipment. In the present study, the colorimetric method based on gold nanoparticles (GNPs) and endonuclease enzyme was used for the detection of P. aeruginosa ETA gene. Firstly, the primers and probe for P. aeruginosa exotoxin A (ETA) gene were designed and checked for specificity by the PCR method. Then, GNPs were synthesized using the citrate reduction method and conjugated with the prepared probe to develop the new nano-biosensor. Next, the extracted target DNA of the bacteria was added to GNP-probe complex to check its efficacy for P. aeruginosa ETA gene diagnosis. A decrease in absorbance was seen when GNP-probe-target DNA cleaved into the small fragments of BamHI endonuclease due to the weakened electrostatic interaction between GNPs and the shortened DNA. The right shift of the absorbance peak from 530 to 562nm occurred after adding the endonuclease. It was measured using a UV-VIS absorption spectroscopy that indicates the existence of the P. aeruginosa ETA gene. Sensitivity was determined in the presence of different concentrations of target DNA of P. aeruginosa. The results obtained from the optimized conditions showed that the absorbance value has linear correlation with concentration of target DNA (R: 0.9850) in the range of 10-50ngmL -1 with the limit detection of 9.899ngmL -1 . Thus, the specificity of the new method for detection of P. aeruginosa was established in comparison with other bacteria. Additionally, the designed assay was quantitatively applied to detect the P. aeruginosa ETA gene from 10 3 to 10 8 CFUmL -1 in real samples with a detection limit of 320CFUmL -1 . Copyright © 2018 Elsevier B.V. All rights reserved.

Landsat based historical (1984-2014) crop water use estimates and trends in the Southwestern United States

NASA Astrophysics Data System (ADS)

Senay, G. B.; Schauer, M.; Friedrichs, M.; Velpuri, N. M.; Singh, R. K.

2016-12-01

Remote sensing-based field scale evapotranspiration (ET) maps are useful for characterizing water use patterns and assessing crop performance. Historical (1984-2014) Landsat-based ET maps were generated for major irrigation districts in the southwestern US. A total of 3,396 Landsat images were processed using the Operational Simplified Surface Energy balance (SSEBop) model that integrates weather and remotely sensed images to estimate monthly and annual ET within the study areas over the 31 years. Model output evaluation and validation using point-based eddy covariance flux tower, gridded-flux data and water balance ET approaches indicated relatively strong association between SSEBop ET and validation datasets. Historical trend analysis of seven agro-hydrologic variables using the Seasonal Mann-Kendall test showed interesting results. In a pair wise comparison, management influenced variables such as actual evapotranspiration (ETa), land surface temperature (Ts) and runoff (Q) were found to be more variable than their corresponding climate counterparts of atmospheric water demand (ETo), air temperature (Ta) and precipitation, responding to the impacts of management decisions. Our results indicated that only air temperature showed a consistent increase (up to 1.2 K) across all 9 irrigation sub-basins during the 31 years. District-wide ETa estimates were used to compute historical crop water use volumes and monetary savings for the Palo Verde Irrigation district (PVID). During the peak crop fallowing program in PVID, the water savings reached a maximum of 85,000 ac-ft per year which is equivalent to a dollar amount of $ 600 million. This study has many applications in planning water resource allocation, monitoring and assessing water usage and performance, and quantifying impacts of climate and land use/land cover changes on water resources. With increased computational efficiency and model development, similar studies can be conducted in other parts of the world.

A coupled stochastic rainfall-evapotranspiration model for hydrological impact analysis

NASA Astrophysics Data System (ADS)

Pham, Minh Tu; Vernieuwe, Hilde; De Baets, Bernard; Verhoest, Niko E. C.

2018-02-01

A hydrological impact analysis concerns the study of the consequences of certain scenarios on one or more variables or fluxes in the hydrological cycle. In such an exercise, discharge is often considered, as floods originating from extremely high discharges often cause damage. Investigating the impact of extreme discharges generally requires long time series of precipitation and evapotranspiration to be used to force a rainfall-runoff model. However, such kinds of data may not be available and one should resort to stochastically generated time series, even though the impact of using such data on the overall discharge, and especially on the extreme discharge events, is not well studied. In this paper, stochastically generated rainfall and corresponding evapotranspiration time series, generated by means of vine copulas, are used to force a simple conceptual hydrological model. The results obtained are comparable to the modelled discharge using observed forcing data. Yet, uncertainties in the modelled discharge increase with an increasing number of stochastically generated time series used. Notwithstanding this finding, it can be concluded that using a coupled stochastic rainfall-evapotranspiration model has great potential for hydrological impact analysis.

Quantifying water and energy budgets and the impacts of climatic and human factors in the Haihe River Basin, China: 1. Model and validation

NASA Astrophysics Data System (ADS)

Guo, Ying; Shen, Yanjun

2015-09-01

We have developed an operational model to simulate water and energy fluxes in the Haihe River Basin (231,800 km2 in size) for the past 28 years. This model is capable of estimating water and energy fluxes of irrigated croplands and heterogeneous grids. The model was validated using actual evapotranspiration (ETa) measured by an eddy covariance system, measured soil moisture in croplands, groundwater level measurements over the piedmont plain and runoff observations in a mountainous catchment. A long-term time series of water and energy balance components were then simulated at a daily time step by integrating remotely sensed information and meteorological data to examine the spatial and temporal distribution and changes in water and energy fluxes in the basin over the past 28 years. The results show that net radiation (Rn) in the mountainous regions is generally higher than that in the plain regions. ETa in the plain regions is higher than that in the mountainous regions mostly because of higher air temperature and larger areas of irrigated farmland. Higher sensible heat flux (H) and lower ETa in the urban areas are possibly due to less vegetation cover, an impervious surface, rapid drainage, and the heat island effect of cities. During the study period, a water deficit continuously occurred in the plain regions because of extensive pumping of groundwater for irrigation to meet the crop water requirements. Irrigation has led to significant groundwater depletion, which poses a substantial challenge to the sustainability of water resources in this basin.

Differential roles of endothelin-1 ETA and ETB receptors and vasoactive intestinal polypeptide in regulation of the airways and the pulmonary vasculature in isolated rat lung.

PubMed

Janosi, Tibor; Peták, Ferenc; Fontao, Fabienne; Morel, Denis R; Beghetti, Maurice; Habre, Walid

2008-11-01

The available treatment strategies against pulmonary hypertension include the administration of endothelin-1 (ET-1) receptor subtype blockers (ET(A) and ET(B) antagonists); vasoactive intestinal polypeptide (VIP) has recently been suggested as a potential new therapeutic agent. We set out to investigate the ability of these agents to protect against the vasoconstriction and impairment of lung function commonly observed in patients with pulmonary hypertension. An ET(A) blocker (BQ123), ET(B) blocker (BQ788), a combination of these selective blockers (ET(A) + ET(B) blockers) or VIP (V6130) was administered into the pulmonary circulation in four groups of perfused normal rat lungs. Pulmonary vascular resistance (PVR) and forced oscillatory lung input impedance (Z(L)) were measured in all groups under baseline conditions and at 1 min intervals following ET-1 administrations. The airway resistance, inertance, tissue damping and elastance were extracted from the Z(L) spectra. While VIP, ET(A) blocker and combined ET(A) and ET(B) blockers significantly prevented the pulmonary vasoconstriction induced by ET-1, ET(B) blockade enhanced the ET-1-induced increases in PVR. In contrast, the ET(A) and ET(B) blockers markedly elevated the ET-1-induced increases in airway resistance, while VIP blunted this constrictor response. Our results suggest that VIP potently acts against the airway and pulmonary vascular constriction mediated by endothelin-1, while the ET(A) and ET(B) blockers exert a differential effect between airway resistance and PVR.

Global X-ray Spectral Variation of Eta Carinae through the 2003 X-ray Minimum

NASA Technical Reports Server (NTRS)

Hamaguchi, K.; Corcoran, M. F.; White, N. E.; Gull, T.; Damineli, A.; Davidson, K.

2006-01-01

We report on the results of the X-ray observing campaign of the massive, evolved star Eta Carinae in 2003 around its recent X-ray Minimum, mainly using data from the XMM-Newton observatory. These imaging observations show that the hard X-ray source associated with the Eta Carinae system does not completely disappear in any of the observations during the Minimum. The variation of the spectral shape revealed two emission components. One newly discovered component did not exhibit any variation on kilo-second to year-long timescales, in a combined analysis with earlier ASCA and ROSAT data, and might represent the collision of a high speed outflow from Eta Carinae with ambient gas clouds. The other emission component was strongly variable in flux but the temperature of the hottest plasma did not vary significantly at any orbital phase. Absorption to the hard emission, was about a factor of three larger than the absorption determined from the cutoff of the soft emission, and reached a maximum of approx.4 x 10(exp 23)/sq cm before the Minimum. The thermal Fe\\rm XXV emission line showed significant excesses on both the red and blue sides of the line outside the Minimum and exhibited a large redward excess during the Minimum. This variation in the line profile probably requires an abrupt change in ionization balance in the shocked gas.

Ecosystem evapotranspiration: Challenges in measurements, estimates, and modeling

USDA-ARS?s Scientific Manuscript database

Evapotranspiration (ET) processes at the leaf-to-landscape scales in multiple land uses have important controls and feedbacks for the local, regional and global climate and water resource systems. Innovative methods, tools, and technologies for improved understanding and quantification of ET and cro...

Comparison of estimates of evapotranspiration and consumptive use in Palo Verde Valley, California

USGS Publications Warehouse

Raymond, Lee H.; Owen-Joyce, Sandra J.

1987-01-01

Estimates of evapotranspiration and consumptive use by vegetation in Palo Verde Valley, California, were compared for calendar years 1981 to 1984. Vegetation types were classified, and the areas covered by each type were computed from Landsat satellite digital-image analysis. Evapotranspiration was calculated by multiplying the area of each vegetation type by a corresponding water use rate adjusted for year-to-year variations in climate. The vegetation classification slightly underestimates the total vegetated area when compared to crop reports, because not all multiple cropping could be identified. The accuracy of evapotranspiration calculated from vegetation classification depends primarily on the correct classification of alfalfa and cotton because alfalfa and cotton have larger acreages and use more water/acre than the other crops in the valley. Consumptive use was calculated using a water budget for each of the 4 years. Estimates of evapotranspiration and consumptive use by vegetation, respectively, were: (1) 439,400 and 483,500 acre-ft in 1981, (2) 430,700 and 452,700 acre-ft in 1982, (3) 402,000 and 364,400 acre-ft in 1983, and (4) 406,700 and 373,800 acre-ft in 1984. Evapotranspiration estimates were lower than consumptive use estimates in 1981 and 1982 and higher in 1983 and 1984. Both estimates were lower in 1983 and 1984 than in 1981 and 1982. Yearly differences in estimates correspond most closely to significant changes in stage of the lower Colorado River caused by flood control releases in 1983 and 1984 and to changes in cropping practices. (Author 's abstract)

APPLICATION OF BIAS AND ADJUSTMENT TECHNIQUES TO THE ETA-CMAQ AIR QUALITY FORECAST

EPA Science Inventory

The current air quality forecast system, based on linking NOAA's Eta meteorological model with EPA's Community Multiscale Air Quality (CMAQ) model, consistently overpredicts surface ozone concentrations, but simulates its day-to-day variability quite well. The ability of bias cor...

Improving evapotranspiration processes in distrubing hydrological models using Remote Sensing derived ET products.

NASA Astrophysics Data System (ADS)

Abitew, T. A.; van Griensven, A.; Bauwens, W.

2015-12-01

Evapotranspiration is the main process in hydrology (on average around 60%), though has not received as much attention in the evaluation and calibration of hydrological models. In this study, Remote Sensing (RS) derived Evapotranspiration (ET) is used to improve the spatially distributed processes of ET of SWAT model application in the upper Mara basin (Kenya) and the Blue Nile basin (Ethiopia). The RS derived ET data is obtained from recently compiled global datasets (continuously monthly data at 1 km resolution from MOD16NBI,SSEBop,ALEXI,CMRSET models) and from regionally applied Energy Balance Models (for several cloud free days). The RS-RT data is used in different forms: Method 1) to evaluate spatially distributed evapotransiration model resultsMethod 2) to calibrate the evotranspiration processes in hydrological modelMethod 3) to bias-correct the evapotranpiration in hydrological model during simulation after changing the SWAT codesAn inter-comparison of the RS-ET products shows that at present there is a significant bias, but at the same time an agreement on the spatial variability of ET. The ensemble mean of different ET products seems the most realistic estimation and was further used in this study.The results show that:Method 1) the spatially mapped evapotranspiration of hydrological models shows clear differences when compared to RS derived evapotranspiration (low correlations). Especially evapotranspiration in forested areas is strongly underestimated compared to other land covers.Method 2) Calibration allows to improve the correlations between the RS and hydrological model results to some extent.Method 3) Bias-corrections are efficient in producing (sesonal or annual) evapotranspiration maps from hydrological models which are very similar to the patterns obtained from RS data.Though the bias-correction is very efficient, it is advised to improve the model results by better representing the ET processes by improved plant/crop computations, improved

Reconstructing the outburst history of Eta Carinae from WFPC2 proper motions

NASA Astrophysics Data System (ADS)

Smith, Nathan

2011-10-01

The HST archive contains several epochs of WFPC2 images of the nebula around Eta Carinae taken over a 15-year timespan, although only the earliest few years of data have been analyzed and published. The fact that all these images were taken with the same instrument, with the same pixel sampling and field distortion, makes them an invaluable resource for accurately measuring the expanding ejecta. So far, analysis of a subset of the data {with only a few year baseline} has shown that Eta Car's nebula was ejected around the time of the Great Eruption in the 1840s, but the full 15-yr dataset has much greater untapped potential. Historical data show multiple peaks in the light curve during the 1840s eruption, possibly the result of violent stellar collisions in the eccentric binary system. Proper motions with the full 15-yr dataset will definitively show if one of these is associated with the main mass ejection. Older material outside the main bipolar nebula traces previous major outbursts of the star with no recorded historical observations. We propose an ambitious reduction and analysis of the complete WFPC2 imaging dataset of Eta Car. These data can reconstruct its violent mass-loss history over the past several thousand years. This will constrain the behavior and timescale of eruptive mass loss in pre-SN evolution. The existence of several epochs over a long timespan will date older parts of the nebula that have not yet been measured, and can even measure the deceleration of the ejecta for the first time, essential for understanding their shaping and shock excitation during the nebula's continuing hydrodynamic evolution.

Lifecycle of South America Monsoon System Simulated by the Regional Eta Model

NASA Astrophysics Data System (ADS)

Cavalcanti, I. F.; Raia, A.; Chou, S. C.; Silveira, V. P.

2017-12-01

The SAMS comprises a set of features over South America that includes the rainy season over large areas of the continent, typical atmospheric circulation and humidity fluxes characteristics and occurrences of the South Atlantic Convergence Zone. The onset and duration of these characteristics are important to several economic sectors, such as Agriculture and Hydropower. Droughts during the summer season, as the 2014 and 2015 cases, or onset delays can affect these sectors. Predictions of the SAMS onset and duration can contribute to management actions. The Eta Regional model represents well the precipitation difference between summer and winter and the related atmospheric circulation differences over South America. Therefore the objective of this study is to analyze the lifecycle of the SAMS simulated by the Eta model to evaluate first the behaviour compared to observations and to further use as a tool to prediction of onset and duration. There are several methods to analyze the lifecycle of the monsoon and here the criterion is based on vertical integrated zonal moisture flux in the monsoon core, which is located at southern Amazonia. The climate simulation was performed with the Eta model using the HadGEM2_ES model, from CMIP5, as lateral boundary condition. The period of analyses is 1980 to 2005. The model results are compared to ERA-Interim reanalysis and GPCP precipitation dataset. The results show the interannual lifecycles and the average for the whole period, as well as the annual cycle of zonal wind, precipitation, temperature and specific humidity. Spatial maps of humidity convergence, atmospheric circulation at low and high levels indicate the changes during the onset and demise.

The role of evapotranspiration in the groundwater hydrochemistry of an arid coastal wetland (Península Valdés, Argentina).

PubMed

Alvarez, María Del Pilar; Carol, Eleonora; Dapeña, Cristina

2015-02-15

Coastal wetlands are complex hydrogeological systems, in which saline groundwater usually occurs. Salinity can be attributed to many origins, such as dissolution of minerals in the sediments, marine contribution and evapotranspiration, among others. The aim of this paper is to evaluate the processes that condition the hydrochemistry of an arid marsh, Playa Fracasso, located in Patagonia, Argentina. A study of the dynamics and geochemistry of the groundwater was carried out in each hydrogeomorphological unit, using major ion and isotope ((18)O and (2)H) data, soil profiles descriptions and measurements, and recording of water tables in relation to the tidal flow. Water balances and analytical models based on isotope data were used to quantify the evaporation processes and to define the role of evaporation in the chemical composition of water. The results obtained show that the groundwater salinity of the marsh comes mainly from the tidal inflow, to which the halite and gypsum dissolution is added. These mineral facies are the result of the total evaporation of the marine water flooding that occurs mostly at the spring high tides. The isotope relationships in the fan and bajada samples show the occurrence of evaporation processes. Such processes, however, are not mainly responsible for the saline content of groundwater, which is actually generated by the dissolution of the typical evaporite facies of the arid environment sediments. It is concluded that the evapotranspiration processes condition groundwater quality. This is not only due to the saline enrichment caused by the evapotranspiration of shallow water, but also because such processes are the main drivers of the formation of soluble salts, which are then incorporated into the water by groundwater or tidal flow. Copyright © 2014 Elsevier B.V. All rights reserved.

Decreasing reference evapotranspiration in a warming climate - A case of Changjiang (Yangtze) River catchment during 1970-2000

NASA Astrophysics Data System (ADS)

Xu, C. Y.; Gong, L. B.; Tong, J.; Chen, D. L.

2006-07-01

This study deals with temporal trends in the Penman-Monteith reference evapotranspiration estimated from standard meteorological observations, observed pan evaporation, and four related meteorological variables during 1970-2000 in the Yangtze River catchment. Relative contributions of the four meteorological variables to changes in the reference evapotranspiration are quantified. The results show that both the reference evapotranspiration and the pan evaporation have significant. decreasing trends in the upper, the middle as well as in the whole Changjiang (Yangtze) River catchment at the 5% significance level, while the air temperature shows a significant increasing trend. The decreasing trend detected in the reference evapotranspiration can be attributed to the significant decreasing trends in the net radiation and the wind speed.

Intercomparison and Uncertainty Assessment of Nine Evapotranspiration Estimates Over South America

NASA Astrophysics Data System (ADS)

Sörensson, Anna A.; Ruscica, Romina C.

2018-04-01

This study examines the uncertainties and the representations of anomalies of a set of evapotranspiration products over climatologically distinct regions of South America. The products, coming from land surface models, reanalysis, and remote sensing, are chosen from sources that are readily available to the community of users. The results show that the spatial patterns of maximum uncertainty differ among metrics, with dry regions showing maximum relative uncertainties of annual mean evapotranspiration, while energy-limited regions present maximum uncertainties in the representation of the annual cycle and monsoon regions in the representation of anomalous conditions. Furthermore, it is found that land surface models driven by observed atmospheric fields detect meteorological and agricultural droughts in dry regions unequivocally. The remote sensing products employed do not distinguish all agricultural droughts and this could be attributed to the forcing net radiation. The study also highlights important characteristics of individual data sets and recommends users to include assessments of sensitivity to evapotranspiration data sets in their studies, depending on region and nature of study to be conducted.

Eta Carinae's Change of State: The End Game

NASA Astrophysics Data System (ADS)

Davidson, Kris

2017-08-01

Eta Car is the only giant-eruption survivor that can be observed well. Hence it is genuinely unique for testing instability theories which are crucial for very massive stars. Fortuitously, a rapid change of state began about 1998. This represents an unexpected stage in the recovery following the Great Eruption (supernova impostor event) seen 170 years ago. Now there are reasons to think that the change of state is nearly complete. HST/STIS has been the main source of information on this phenomenon, and is the only instrument that can show the final (or nearly final) state. Therefore we propose to complete this record in Cy 25. The archival value is very high, because similar observations will later be impossible; the star is changing irreversibly. HST is needed, because UV is essential and because all ground-based spectroscopy of eta Car is heavily contaminated by emission lines formed about 0.3 arcsec away. For this object each HST orbit produces many high-quality spectra. The same data apply to other problems, e.g. exotic emission processes in the ejecta, bipolar structures, and the nature of the companion star.We propose STIS observations: (1) A final update of the central star's wind spectrum at selected NUV-to-red wavelengths. (2) Brief UV spectroscopy with the MAMA echelle. This will be the only such data obtained at a time when the companion star is near apoastron. (3) Special sampling of the Homunculus ejecta-nebula using STIS/CCD with long exposure times. This was done once before, in 2000, and major changes have occurred since then.

Nucleotide sequences of immunoglobulin eta genes of chimpanzee and orangutan: DNA molecular clock and hominoid evolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakoyama, Y.; Hong, K.J.; Byun, S.M.

To determine the phylogenetic relationships among hominoids and the dates of their divergence, the complete nucleotide sequences of the constant region of the immunoglobulin eta-chain (C/sub eta1/) genes from chimpanzee and orangutan have been determined. These sequences were compared with the human eta-chain constant-region sequence. A molecular clock (silent molecular clock), measured by the degree of sequence divergence at the synonymous (silent) positions of protein-encoding regions, was introduced for the present study. From the comparison of nucleotide sequences of ..cap alpha../sub 1/-antitrypsin and ..beta..- and delta-globulin genes between humans and Old World monkeys, the silent molecular clock was calibrated: themore » mean evolutionary rate of silent substitution was determined to be 1.56 x 10/sup -9/ substitutions per site per year. Using the silent molecular clock, the mean divergence dates of chimpanzee and orangutan from the human lineage were estimated as 6.4 +/- 2.6 million years and 17.3 +/- 4.5 million years, respectively. It was also shown that the evolutionary rate of primate genes is considerably slower than those of other mammalian genes.« less

The Abundance of Iron-Peak Elements and the Dust Composition in eta Carinae: Manganese

NASA Technical Reports Server (NTRS)

Bautista, M. A.; Melendez, M.; Hartman, H.; Gull, T. R.; Lodders, K.

2010-01-01

We study the chemical abundances of the Strontium Filament found in the ejecta of (eta) Carinae. In particular, we derive the abundances of iron-peak elements front spectra of their singly ionized ions present in the optical/IR spectra. In this paper we analyze the spectrum of Mn II using a new non-LTE model for this system. In constructing this models we carried out theoretical calculations of radiative transition rates and electron impact excitation rate coefficients. We find that relative to Ni the gas phase abundance ratio of Mn is roughly solar, similar to the Cr abundance but in contrast to the large enhancements in the abundances of Sc and Ti. NVe interpret this result as an indication of non-equilibrium condensation in the ejecta of (eta) Carinae.

Dynamics and Predictability of The Eta Regional Model: The Role of Domain Size

NASA Astrophysics Data System (ADS)

Vannitsem, S.; Chomé, F.; Nicolis, C.

This paper investigates the dynamical properties of the Eta model, a state-of-the- art nested limited-area model, following the approach previously developed by the present authors. It is first shown that the intrinsic dynamics of the model depends crucially on the size of the domain, with a non-chaotic behavior for small domains, supporting earlier findings on the absence of sensitivity to the initial conditions in these models. The quality of the predictions of several Eta model versions differing by their domain size is next evaluated and compared with the Avn analyses on a targeted region, centered on France. Contrary to what is usually taken for granted, a non-trivial relation between predictability and domain size is found, the best model versions be- ing the ones integrated on the smallest and the largest domain sizes. An explanation in connection with the intrinsic dynamics of the model is advanced.

Intercomparison of Evapotranspiration Over the Savannah Volta Basin in West Africa Using Remote Sensing Data

PubMed Central

Opoku-Duah, S.; Donoghue, D.N.M.; Burt, T. P.

2008-01-01

This paper compares evapotranspiration estimates from two complementary satellite sensors – NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) and ESA's ENVISAT Advanced Along-Track Scanning Radiometer (AATSR) over the savannah area of the Volta basin in West Africa. This was achieved through solving for evapotranspiration on the basis of the regional energy balance equation, which was computationally-driven by the Surface Energy Balance Algorithm for Land algorithm (SEBAL). The results showed that both sensors are potentially good sources of evapotranspiration estimates over large heterogeneous landscapes. The MODIS sensor measured daily evapotranspiration reasonably well with a strong spatial correlation (R2=0.71) with Landsat ETM+ but underperformed with deviations up to ∼2.0 mm day-1, when compared with local eddy correlation observations and the Penman-Monteith method mainly because of scale mismatch. The AATSR sensor produced much poorer correlations (R2=0.13) with Landsat ETM+ and conventional ET methods also because of differences in atmospheric correction and sensor calibration over land. PMID:27879847

Actividad actual y resultados de las observaciones en Base Belgrano Antártida

NASA Astrophysics Data System (ADS)

Recabarren, P.; Mosconi, M.; Ferreiro, D.; Lazarte, G.; Hutka, J.; García Lambas, D.; Ozu, R.

Several aspects of the experience acquired in ``J. L. Sérsic'' Antarctic Astronomical Station, at 78 degrees South, during the period 1995-1997 are analysed. We show results of 'seeing' measurements, extinction coeficients, monitoring of Eta Carinae, meteorogical conditions and logistic support. Seeing measurements show average values of 4.02" ('95), 5.25" ('96) y 4.43" (till July '97). We have found photometrical variations of Eta Car with a particular behaviour near June 5.

Estimation of evapotranspiration in an arid region by remote sensing—A case study in the middle reaches of the Heihe River Basin

NASA Astrophysics Data System (ADS)

Li, Xingmin; Lu, Ling; Yang, Wenfeng; Cheng, Guodong

2012-07-01

Estimating surface evapotranspiration is extremely important for the study of water resources in arid regions. Data from the National Oceanic and Atmospheric Administration's Advanced Very High Resolution Radiometer (NOAA/AVHRR), meteorological observations and data obtained from the Watershed Allied Telemetry Experimental Research (WATER) project in 2008 are applied to the evaporative fraction model to estimate evapotranspiration over the Heihe River Basin. The calculation method for the parameters used in the model and the evapotranspiration estimation results are analyzed and evaluated. The results observed within the oasis and the banks of the river suggest that more evapotranspiration occurs in the inland river basin in the arid region from May to September. Evapotranspiration values for the oasis, where the land surface types and vegetations are highly variable, are relatively small and heterogeneous. In the Gobi desert and other deserts with little vegetation, evapotranspiration remains at its lowest level during this period. These results reinforce the conclusion that rational utilization of water resources in the oasis is essential to manage the water resources in the inland river basin. In the remote sensing-based evapotranspiration model, the accuracy of the parameter estimate directly affects the accuracy of the evapotranspiration results; more accurate parameter values yield more precise values for evapotranspiration. However, when using the evaporative fraction to estimate regional evapotranspiration, better calculation results can be achieved only if evaporative fraction is constant in the daytime.

On estimating total daily evapotranspiration from remote surface temperature measurements

NASA Technical Reports Server (NTRS)

Carlson, Toby N.; Buffum, Martha J.

1989-01-01

A method for calculating daily evapotranspiration from the daily surface energy budget using remotely sensed surface temperature and several meteorological variables is presented. Vaules of the coefficients are determined from simulations with a one-dimensional boundary layer model with vegetation cover. Model constants are obtained for vegetation and bare soil at two air temperature and wind speed levels over a range of surface roughness and wind speeds. A different means of estimating the daily evapotranspiration based on the time rate of increase of surface temperature during the morning is also considered. Both the equations using our model-derived constants and field measurements are evaluated, and a discussion of sources of error in the use of the formulation is given.

Sensitivity of the projected hydroclimatic environment of the Delaware River basin to formulation of potential evapotranspiration

USGS Publications Warehouse

Williamson, Tanja N.; Nystrom, Elizabeth A.; Milly, Paul C.D.

2016-01-01

The Delaware River Basin (DRB) encompasses approximately 0.4 % of the area of the United States (U.S.), but supplies water to 5 % of the population. We studied three forested tributaries to quantify the potential climate-driven change in hydrologic budget for two 25-year time periods centered on 2030 and 2060, focusing on sensitivity to the method of estimating potential evapotranspiration (PET) change. Hydrology was simulated using the Water Availability Tool for Environmental Resources (Williamson et al. 2015). Climate-change scenarios for four Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate models (GCMs) and two Representative Concentration Pathways (RCPs) were used to derive monthly change factors for temperature (T), precipitation (PPT), and PET according to the energy-based method of Priestley and Taylor (1972). Hydrologic simulations indicate a general increase in annual (especially winter) streamflow (Q) as early as 2030 across the DRB, with a larger increase by 2060. This increase in Q is the result of (1) higher winter PPT, which outweighs an annual actual evapotranspiration (AET) increase and (2) (for winter) a major shift away from storage of PPT as snow pack. However, when PET change is evaluated instead using the simpler T-based method of Hamon (1963), the increases in Q are small or even negative. In fact, the change of Q depends as much on PET method as on time period or RCP. This large sensitivity and associated uncertainty underscore the importance of exercising caution in the selection of a PET method for use in climate-change analyses.

Should Bouchet's hypothesis be taken into account in rainfall-runoff modelling? An assessment over 308 catchments

NASA Astrophysics Data System (ADS)

Oudin, Ludovic; Michel, Claude; Andréassian, Vazken; Anctil, François; Loumagne, Cécile

2005-12-01

An implementation of the complementary relationship hypothesis (Bouchet's hypothesis) for estimating regional evapotranspiration within two rainfall-runoff models is proposed and evaluated in terms of streamflow simulation efficiency over a large sample of 308 catchments located in Australia, France and the USA. Complementary relationship models are attractive approaches to estimating actual evapotranspiration because they rely solely on climatic variables. They are even more interesting since they are supported by a conceptual description underlying the interactions between the evapotranspirating surface and the atmospheric boundary layer, which was highlighted by Bouchet (1963). However, these approaches appear to be in contradiction with the methods prevailing in rainfall-runoff models, which compute actual evapotranspiration using soil moisture accounting procedures. The approach adopted in this article is to introduce the estimation of actual evapotranspiration provided by complementary relationship models (complementary relationship for areal evapotranspiration and advection aridity) into two rainfall-runoff models. Results show that directly using the complementary relationship approach to estimate actual evapotranspiration does not give better results than the soil moisture accounting procedures. Finally, we discuss feedback mechanisms between potential evapotranspiration and soil water availability, and their possible impact on rainfall-runoff modelling. Copyright

Combining surface reanalysis and remote sensing data for monitoring evapotranspiration

USGS Publications Warehouse

Marshall, M.; Tu, K.; Funk, C.; Michaelsen, J.; Williams, Pat; Williams, C.; Ardö, J.; Marie, B.; Cappelaere, B.; Grandcourt, A.; Nickless, A.; Noubellon, Y.; Scholes, R.; Kutsch, W.

2012-01-01

Climate change is expected to have the greatest impact on the world's poor. In the Sahel, a climatically sensitive region where rain-fed agriculture is the primary livelihood, expected decreases in water supply will increase food insecurity. Studies on climate change and the intensification of the water cycle in sub-Saharan Africa are few. This is due in part to poor calibration of modeled actual evapotranspiration (AET), a key input in continental-scale hydrologic models. In this study, a model driven by dynamic canopy AET was combined with the Global Land Data Assimilation System realization of the NOAH Land Surface Model (GNOAH) wet canopy and soil AET for monitoring purposes in sub-Saharan Africa. The performance of the hybrid model was compared against AET from the GNOAH model and dynamic model using eight eddy flux towers representing major biomes of sub-Saharan Africa. The greatest improvements in model performance are at humid sites with dense vegetation, while performance at semi-arid sites is poor, but better than individual models. The reduction in errors using the hybrid model can be attributed to the integration of a dynamic vegetation component with land surface model estimates, improved model parameterization, and reduction of multiplicative effects of uncertain data.

29 CFR 500.132 - Applicable Federal standards: ETA and OSHA housing standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... promulgated by the Occupational Safety and Health Administration, at 29 CFR 1910.142. Except as provided in... Migrant Workers Housing Safety and Health § 500.132 Applicable Federal standards: ETA and OSHA housing... Occupational Safety and Health Act. (2) A person who owns or controls a facility or real property to be used...

29 CFR 500.132 - Applicable Federal standards: ETA and OSHA housing standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... promulgated by the Occupational Safety and Health Administration, at 29 CFR 1910.142. Except as provided in... Migrant Workers Housing Safety and Health § 500.132 Applicable Federal standards: ETA and OSHA housing... Occupational Safety and Health Act. (2) A person who owns or controls a facility or real property to be used...

Branching fractions for {chi}{sub cJ{yields}}pp{pi}{sup 0}, pp{eta}, and pp{omega}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onyisi, P. U. E.; Rosner, J. L.; Alexander, J. P.

2010-07-01

Using a sample of 25.9x10{sup 6} {psi}(2S) decays acquired with the CLEO-c detector at the CESR e{sup +}e{sup -} collider, we report branching fractions for the decays {chi}{sub cJ{yields}}pp{pi}{sup 0}, pp{eta}, and pp{omega}, with J=0, 1, 2. Our results for B({chi}{sub cJ{yields}}pp{pi}{sup 0}) and B({chi}{sub cJ{yields}}pp{eta}) are consistent with, but more precise than, previous measurements. Furthermore, we include the first measurement of B({chi}{sub cJ{yields}}pp{omega}).

Assessing the ability of potential evapotranspiration models in capturing dynamics of evaporative demand across various biomes and climatic regimes with ChinaFLUX measurements

NASA Astrophysics Data System (ADS)

Zheng, Han; Yu, Guirui; Wang, Qiufeng; Zhu, Xianjin; Yan, Junhua; Wang, Huimin; Shi, Peili; Zhao, Fenghua; Li, Yingnian; Zhao, Liang; Zhang, Junhui; Wang, Yanfen

2017-08-01

Estimates of atmospheric evaporative demand have been widely required for a variety of hydrological analyses, with potential evapotranspiration (PET) being an important measure representing evaporative demand of actual vegetated surfaces under given metrological conditions. In this study, we assessed the ability of various PET models in capturing long-term (typically 2003-2011) dynamics of evaporative demand at eight ecosystems across various biomes and climatic regimes in China. Prior to assessing PET dynamics, we first examined the reasonability of fourteen PET models in representing the magnitudes of evaporative demand using eddy-covariance actual evapotranspiration (AET) as an indicator. Results showed that the robustness of the fourteen PET models differed somewhat across the sites, and only three PET models could produce reasonable magnitudes of evaporative demand (i.e., PET ≥ AET on average) for all eight sites, including the: (i) Penman; (ii) Priestly-Taylor and (iii) Linacre models. Then, we assessed the ability of these three PET models in capturing dynamics of evaporative demand by comparing the annual and seasonal trends in PET against the equivalent trends in AET and precipitation (P) for particular sites. Results indicated that nearly all the three PET models could faithfully reproduce the dynamics in evaporative demand for the energy-limited conditions at both annual and seasonal scales, while only the Penman and Linacre models could represent dynamics in evaporative demand for the water-limited conditions. However, the Linacre model was unable to reproduce the seasonal switches between water- and energy-limited states for some sites. Our findings demonstrated that the choice of PET models would be essential for the evaporative demand analyses and other related hydrological analyses at different temporal and spatial scales.

Land surface evapotranspiration modelling at the regional scale

NASA Astrophysics Data System (ADS)

Raffelli, Giulia; Ferraris, Stefano; Canone, Davide; Previati, Maurizio; Gisolo, Davide; Provenzale, Antonello

2017-04-01

Climate change has relevant implications for the environment, water resources and human life in general. The observed increment of mean air temperature, in addition to a more frequent occurrence of extreme events such as droughts, may have a severe effect on the hydrological cycle. Besides climate change, land use changes are assumed to be another relevant component of global change in terms of impacts on terrestrial ecosystems: socio-economic changes have led to conversions between meadows and pastures and in most cases to a complete abandonment of grasslands. Water is subject to different physical processes among which evapotranspiration (ET) is one of the most significant. In fact, ET plays a key role in estimating crop growth, water demand and irrigation water management, so estimating values of ET can be crucial for water resource planning, irrigation requirement and agricultural production. Potential evapotranspiration (PET) is the amount of evaporation that occurs when a sufficient water source is available. It can be estimated just knowing temperatures (mean, maximum and minimum) and solar radiation. Actual evapotranspiration (AET) is instead the real quantity of water which is consumed by soil and vegetation; it is obtained as a fraction of PET. The aim of this work was to apply a simplified hydrological model to calculate AET for the province of Turin (Italy) in order to assess the water content and estimate the groundwater recharge at a regional scale. The soil is seen as a bucket (FAO56 model, Allen et al., 1998) made of different layers, which interact with water and vegetation. The water balance is given by precipitations (both rain and snow) and dew as positive inputs, while AET, runoff and drainage represent the rate of water escaping from soil. The difference between inputs and outputs is the water stock. Model data inputs are: soil characteristics (percentage of clay, silt, sand, rocks and organic matter); soil depth; the wilting point (i.e. the

Estimating Daily Evapotranspiration Based on A Model of Evapotranspiration Fraction (EF) for Mixed Pixels

NASA Astrophysics Data System (ADS)

Xin, X.; Li, F.; Peng, Z.; Qinhuo, L.

2017-12-01

Land surface heterogeneities significantly affect the reliability and accuracy of remotely sensed evapotranspiration (ET), and it gets worse for lower resolution data. At the same time, temporal scale extrapolation of the instantaneous latent heat flux (LE) at satellite overpass time to daily ET are crucial for applications of such remote sensing product. The purpose of this paper is to propose a simple but efficient model for estimating daytime evapotranspiration considering heterogeneity of mixed pixels. In order to do so, an equation to calculate evapotranspiration fraction (EF) of mixed pixels was derived based on two key assumptions. Assumption 1: the available energy (AE) of each sub-pixel equals approximately to that of any other sub-pixels in the same mixed pixel within acceptable margin of bias, and as same as the AE of the mixed pixel. It's only for a simpification of the equation, and its uncertainties and resulted errors in estimated ET are very small. Assumption 2: EF of each sub-pixel equals to the EF of the nearest pure pixel(s) of same land cover type. This equation is supposed to be capable of correcting the spatial scale error of the mixed pixels EF and can be used to calculated daily ET with daily AE data.The model was applied to an artificial oasis in the midstream of Heihe River. HJ-1B satellite data were used to estimate the lumped fluxes at the scale of 300 m after resampling the 30-m resolution datasets to 300 m resolution, which was used to carry on the key step of the model. The results before and after correction were compare to each other and validated using site data of eddy-correlation systems. Results indicated that the new model is capable of improving accuracy of daily ET estimation relative to the lumped method. Validations at 12 sites of eddy-correlation systems for 9 days of HJ-1B overpass showed that the R² increased to 0.82 from 0.62; the RMSE decreased to 1.60 MJ/m² from 2.47MJ/m²; the MBE decreased from 1.92 MJ/m² to 1

Lower responsiveness of canopy evapotranspiration rate than of leaf stomatal conductance to open-air CO2 elevation in rice.

PubMed

Shimono, Hiroyuki; Nakamura, Hirofumi; Hasegawa, Toshihiro; Okada, Masumi

2013-08-01

An elevated atmospheric CO2 concentration ([CO2 ]) can reduce stomatal conductance of leaves for most plant species, including rice (Oryza sativa L.). However, few studies have quantified seasonal changes in the effects of elevated [CO2 ] on canopy evapotranspiration, which integrates the response of stomatal conductance of individual leaves with other responses, such as leaf area expansion, changes in leaf surface temperature, and changes in developmental stages, in field conditions. We conducted a field experiment to measure seasonal changes in stomatal conductance of the uppermost leaves and in the evapotranspiration, transpiration, and evaporation rates using a lysimeter method. The study was conducted for flooded rice under open-air CO2 elevation. Stomatal conductance decreased by 27% under elevated [CO2 ], averaged throughout the growing season, and evapotranspiration decreased by an average of 5% during the same period. The decrease in daily evapotranspiration caused by elevated [CO2 ] was more significantly correlated with air temperature and leaf area index (LAI) rather than with other parameters of solar radiation, days after transplanting, vapor-pressure deficit and FAO reference evapotranspiration. This indicates that higher air temperatures, within the range from 16 to 27 °C, and a larger LAI, within the range from 0 to 4 m(2)  m(-2) , can increase the magnitude of the decrease in evapotranspiration rate caused by elevated [CO2 ]. The crop coefficient (i.e. the evapotranspiration rate divided by the FAO reference evapotranspiration rate) was 1.24 at ambient [CO2 ] and 1.17 at elevated [CO2 ]. This study provides the first direct measurement of the effects of elevated [CO2 ] on rice canopy evapotranspiration under open-air conditions using the lysimeter method, and the results will improve future predictions of water use in rice fields. © 2013 John Wiley & Sons Ltd.

Fact Sheet on Evapotranspiration Cover Systems for Waste Containment

EPA Pesticide Factsheets

This Fact Sheet updates the 2003 Fact Sheet on Evapotranspiration Covers and provides information on the regulatory setting for ET covers, general considerations in their design, performance, and monitoring, and status at the time of writing (2011).

FUV Detection of the Primary Star of eta Carinae

NASA Astrophysics Data System (ADS)

Davidson, K.; Smith, N.

2006-06-01

Using FUSE data, Iping et al (2005, ApJ 633, L37) report a direct detection of the elusive hot companion of eta Car. We argue, however, that much of the observed emission represents the primary star, with no proof that any of it comes from a secondary star. The hypothetical companion should dominate the ionizing radiation below 912 A, but this is not true for wavelengths around 1100 A observed with FUSE. Moreover, since a companion's UV would be partially reprocessed by the primary star's wind, any detection is likely to be ambiguous.The non-spherical primary wind allows production of strong UV radiation at low latitudes (Smith et al 2003, ApJ 586, 432), an effect that spherical models don't include. The N II 1085 feature, the relatively slow wind velocities seen by FUSE, and other details are characteristic of the primary wind, not the secondary. Zanella et al. (1984, A&A 137, 79) suggested that eta Car's far UV disappears during a spectroscopic event due to a shell ejection. The FUSE observations may be regarded as confirmation of that conjecture, which made no reference to a secondary star. The 2003 spectroscopic event was probably a mass ejection or a wind-disturbance episode, not merely an eclipse as assumed by Iping et al. A hot companion star seems likely to account for the ionizing UV and the X-ray variability, but the FUSE data do not confirm its existence.

Spectroscopic studies of Fe(III) ion-exchanged ETS-10 and ETAS-10 molecular sieves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sommerfeld, D.A.; Ellis, W.R. Jr.; Eyring, E.M.

1992-11-26

Two new titanium silicate molecular sieves, designated ETS-10 and ETAS-10, have been ion-exchanged with Fe(III). Both products exhibit prominent EPR signals, at g = 6.0 and 4.3, that are assigned to populations of ferric iron on the surface and in the interior cavities, respectively, of the molecular sieve microcrystals. Corollary XPS measurements on these samples indicate that a substantial fraction of the surface iron is present as Fe(II). Chemical modification procedures have been explored in an effort to produce ion-exchanged materials containing no exterior iron. Acid treatment (pH 1.0) proved to be an effective means of achieving this goal inmore » the case of ETS-10-based materials. ETAS-10-based samples do not retain their crystallinity under these conditions. 35 refs., 4 figs., 2 tabs.« less

Was the nineteenth century giant eruption of Eta Carinae a merger event in a triple system?

NASA Astrophysics Data System (ADS)

Portegies Zwart, S. F.; van den Heuvel, E. P. J.

2016-03-01

We discuss the events that led to the giant eruption of Eta Carinae, and find that the mid-nineteenth century (in 1838-1843) giant mass-loss outburst has the characteristics of being produced by the merger event of a massive close binary, triggered by the gravitational interaction with a massive third companion star, which is the current binary companion in the Eta Carinae system. We come to this conclusion by a combination of theoretical arguments supported by computer simulations using the Astrophysical Multipurpose Software Environment. According to this model the ˜90 M⊙ present primary star of the highly eccentric Eta Carinae binary system is the product of this merger, and its ˜30 M⊙ companion originally was the third star in the system. In our model, the Homunculus nebula was produced by an extremely enhanced stellar wind, energized by tidal energy dissipation prior to the merger, which enormously boosted the radiation-driven wind mass-loss. The current orbital plane is then aligned with the equatorial plane of the Homunculus, and the symmetric lobes are roughly aligned with the argument of periastron of the current Eta Carina binary. The merger itself then occurred in 1838, which resulted in a massive asymmetric outflow in the equatorial plane of the Homunculus. The 1843 outburst can in our model be attributed to the subsequent encounter when the companion star (once the outermost star in the triple system) plunges through the bloated envelope of the merger product, once when it passed periastron again. We predict that the system has an excess space velocity of order 50 km s-1 in the equatorial plane of the Homunculus. Our triple model gives a viable explanation for the high runaway velocities typically observed in LBVs.

Uncertainty Quantification of Evapotranspiration and Infiltration from Modeling and Historic Time Series at the Savannah River F-Area

NASA Astrophysics Data System (ADS)

Faybishenko, B.; Flach, G. P.

2012-12-01

The objectives of this presentation are: (a) to illustrate the application of Monte Carlo and fuzzy-probabilistic approaches for uncertainty quantification (UQ) in predictions of potential evapotranspiration (PET), actual evapotranspiration (ET), and infiltration (I), using uncertain hydrological or meteorological time series data, and (b) to compare the results of these calculations with those from field measurements at the U.S. Department of Energy Savannah River Site (SRS), near Aiken, South Carolina, USA. The UQ calculations include the evaluation of aleatory (parameter uncertainty) and epistemic (model) uncertainties. The effect of aleatory uncertainty is expressed by assigning the probability distributions of input parameters, using historical monthly averaged data from the meteorological station at the SRS. The combined effect of aleatory and epistemic uncertainties on the UQ of PET, ET, and Iis then expressed by aggregating the results of calculations from multiple models using a p-box and fuzzy numbers. The uncertainty in PETis calculated using the Bair-Robertson, Blaney-Criddle, Caprio, Hargreaves-Samani, Hamon, Jensen-Haise, Linacre, Makkink, Priestly-Taylor, Penman, Penman-Monteith, Thornthwaite, and Turc models. Then, ET is calculated from the modified Budyko model, followed by calculations of I from the water balance equation. We show that probabilistic and fuzzy-probabilistic calculations using multiple models generate the PET, ET, and Idistributions, which are well within the range of field measurements. We also show that a selection of a subset of models can be used to constrain the uncertainty quantification of PET, ET, and I.

Eclipse and Collapse of the Colliding Wind X-ray Emission from Eta Carinae

NASA Technical Reports Server (NTRS)

Hamaguchi, Kenji; Corcoran, Michael F.

2012-01-01

X-ray emission from the massive stellar binary system, Eta Carinae, drops strongly around periastron passage; the event is called the X-ray minimum. We launched a focused observing campaign in early 2009 to understand the mechanism of causing the X-ray minimum. During the campaign, hard X-ray emission (<10 keV) from Eta Carinae declined as in the previous minimum, though it recovered a month earlier. Extremely hard X-ray emission between 15-25 keV, closely monitored for the first time with the Suzaku HXD/PIN, decreased similarly to the hard X-rays, but it reached minimum only after hard X-ray emission from the star had already began to recover. This indicates that the X-ray minimum is produced by two composite mechanisms: the thick primary wind first obscured the hard, 2-10 keV thermal X-ray emission from the wind-wind collision (WWC) plasma; the WWC activity then decays as the two stars reach periastron.

The ETA-II linear induction accelerator and IMP wiggler: A high-average-power millimeter-wave free-electron-laser for plasma heating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, S.L.; Scharlemann, E.T.

1992-05-01

We have constructed a 140-GHz free-electron laser to generate high-average-power microwaves for heating the MTX tokamak plasma. A 5.5-m steady-state wiggler (intense Microwave Prototype-IMP) has been installed at the end of the upgraded 60-cell ETA-II accelerator, and is configured as an FEL amplifier for the output of a 140-GHz long-pulse gyrotron. Improvements in the ETA-II accelerator include a multicable-feed power distribution network, better magnetic alignment using a stretched-wire alignment technique (SWAT). and a computerized tuning algorithm that directly minimizes the transverse sweep (corkscrew motion) of the electron beam. The upgrades were first tested on the 20-cell, 3-MeV front end ofmore » ETA-II and resulted in greatly improved energy flatness and reduced corkscrew motion. The upgrades were then incorporated into the full 60-cell configuration of ETA-II, along with modifications to allow operation in 50-pulse bursts at pulse repetition frequencies up to 5 kHz. The pulse power modifications were developed and tested on the High Average Power Test Stand (HAPTS), and have significantly reduced the voltage and timing jitter of the MAG 1D magnetic pulse compressors. The 2-3 kA. 6-7 MeV beam from ETA-II is transported to the IMP wiggler, which has been reconfigured as a laced wiggler, with both permanent magnets and electromagnets, for high magnetic field operation. Tapering of the wiggler magnetic field is completely computer controlled and can be optimized based on the output power. The microwaves from the FEL are transmitted to the MTX tokamak by a windowless quasi-optical microwave transmission system. Experiments at MTX are focused on studies of electron-cyclotron-resonance heating (ECRH) of the plasma. We summarize here the accelerator and pulse power modifications, and describe the status of ETA-II, IMP, and MTX operations.« less

Groundwater-supported evapotranspiration within glaciated watersheds under conditions of climate change

NASA Astrophysics Data System (ADS)

Cohen, Denis; Person, Mark; Daannen, Ronnie; Locke, Sharon; Dahlstrom, Dave; Zabielski, Victor; Winter, Thomas C.; Rosenberry, Donald O.; Wright, Herb; Ito, Emi; Nieber, John L.; Gutowski, William J.

2006-04-01

This paper analyzes the effects of geology and geomorphology on surface-water/-groundwater interactions, evapotranspiration, and recharge under conditions of long-term climatic change. Our analysis uses hydrologic data from the glaciated Crow Wing watershed in central Minnesota, USA, combined with a hydrologic model of transient coupled unsaturated/saturated flow (HYDRAT2D). Analysis of historical water-table (1970-1993) and lake-level (1924-2002) records indicates that larger amplitude and longer period fluctuations occur within the upland portions of watersheds due to the response of the aquifer system to relatively short-term climatic fluctuations. Under drought conditions, lake and water-table levels fell by as much as 2-4 m in the uplands but by 1 m in the lowlands. The same pattern can be seen on millennial time scales. Analysis of Holocene lake-core records indicates that Moody Lake, located near the outlet of the Crow Wing watershed, fell by as much as 4 m between about 4400 and 7000 yr BP. During the same time, water levels in Lake Mina, located near the upland watershed divide, fell by about 15 m. Reconstructed Holocene climate as represented by HYDRAT2D gives somewhat larger drops (6 and 24 m for Moody Lake and Lake Mina, respectively). The discrepancy is probably due to the effect of three-dimensional flow. A sensitivity analysis was also carried out to study how aquifer hydraulic conductivity and land-surface topography can influence water-table fluctuations, wetlands formation, and evapotranspiration. The models were run by recycling a wet year (1985, 87 cm annual precipitation) over a 10-year period followed by 20 years of drier and warmer climate (1976, 38 cm precipitation). Model results indicated that groundwater-supported evapotranspiration accounted for as much as 12% (10 cm) of evapotranspiration. The aquifers of highest hydraulic conductivity had the least amount of groundwater-supported evapotranspiration owing to a deep water table. Recharge

Groundwater-supported evapotranspiration within glaciated watersheds under conditions of climate change

USGS Publications Warehouse

Cohen, D.; Person, M.; Daannen, R.; Locke, S.; Dahlstrom, D.; Zabielski, V.; Winter, T.C.; Rosenberry, D.O.; Wright, H.; Ito, E.; Nieber, J.L.; Gutowski, W.J.

2006-01-01

This paper analyzes the effects of geology and geomorphology on surface-water/-groundwater interactions, evapotranspiration, and recharge under conditions of long-term climatic change. Our analysis uses hydrologic data from the glaciated Crow Wing watershed in central Minnesota, USA, combined with a hydrologic model of transient coupled unsaturated/saturated flow (HYDRAT2D). Analysis of historical water-table (1970-1993) and lake-level (1924-2002) records indicates that larger amplitude and longer period fluctuations occur within the upland portions of watersheds due to the response of the aquifer system to relatively short-term climatic fluctuations. Under drought conditions, lake and water-table levels fell by as much as 2-4 m in the uplands but by 1 m in the lowlands. The same pattern can be seen on millennial time scales. Analysis of Holocene lake-core records indicates that Moody Lake, located near the outlet of the Crow Wing watershed, fell by as much as 4 m between about 4400 and 7000 yr BP. During the same time, water levels in Lake Mina, located near the upland watershed divide, fell by about 15 m. Reconstructed Holocene climate as represented by HYDRAT2D gives somewhat larger drops (6 and 24 m for Moody Lake and Lake Mina, respectively). The discrepancy is probably due to the effect of three-dimensional flow. A sensitivity analysis was also carried out to study how aquifer hydraulic conductivity and land-surface topography can influence water-table fluctuations, wetlands formation, and evapotranspiration. The models were run by recycling a wet year (1985, 87 cm annual precipitation) over a 10-year period followed by 20 years of drier and warmer climate (1976, 38 cm precipitation). Model results indicated that groundwater-supported evapotranspiration accounted for as much as 12% (10 cm) of evapotranspiration. The aquifers of highest hydraulic conductivity had the least amount of groundwater-supported evapotranspiration owing to a deep water table. Recharge

Evapotranspiration using a satellite-based surface energy balance with standardized ground control

NASA Astrophysics Data System (ADS)

Trezza, Ricardo

This study evaluated the potential of using the S&barbelow;urface E&barbelow;nergy Ḇalance A&barbelow;lgorithm for Ḻand (SEBAL) as a means for estimating evapotranspiration (ET) for local and regional scales in Southern Idaho. The original SEBAL model was refined during this study to provide better estimation of ET in agricultural areas and to make more reliable estimates of ET from other surfaces as well, including mountainous terrain. The modified version of SEBAL used in this study, termed as SEBALID (ID stands for Idaho) includes standardization of the two SEBAL "anchor" pixels, the use of a water balance model to track top soil moisture, adaptation of components of SEBAL for better prediction of the surface energy balance in mountains and sloping terrain, and use of the ratio between actual ET and alfalfa reference evapotranspiration (ET r) as a means for obtaining the temporal integration of instantaneous ET to daily and seasonal values. Validation of the SEBALID model at a local scale was performed by comparing lysimeter ET measurements from the USDA-ARS facility at Kimberly, Idaho, with ET predictions by SEBAL using Landsat 5 TM imagery. Comparison of measured and predicted ET values was challenging due to the resolution of the Landsat thermal band (120m x 120m) and the relatively small size of the lysimeter fields. In the cases where thermal information was adequate, SEBALID predictions were close to the measured values of ET in the lysimeters. Application of SEBALID at a regional scale was performed using Landsat 7 ETM+ and Landsat 5 TM imagery for the Eastern Snake Plain Aquifer (ESPA) region in Idaho during 2000. The results indicated that SEBALID performed well for predicting daily and seasonal ET for agricultural areas. Some unreasonable results were obtained for desert and basalt areas, due to uncertainties of the prediction of surface parameters. In mountains, even though validation of results was not possible, the values of ET obtained

Finite-energy sum rules in eta photoproduction off a nucleon

DOE PAGES

Nys, Jannes; Mathieu, V.; Fernandez-Ramirez, Cesar; ...

2017-02-15

The reactionmore » $${\\gamma}N \\to {\\eta}N$$ is studied in the high-energy regime (with photon lab energies $$E_{\\gamma}^{\\textrm{lab}} > 4$$ GeV) using information from the resonance region through the use of finite-energy sum rules (FESR). We illustrate how analyticity allows one to map the t-dependence of the unknown Regge residue functions. As a result, we provide predictions for the energy dependence of the beam asymmetry at high energies.« less

Exploring the use of WRF-3DVar for Estimating reference evapotranspiration in semi arid regions

NASA Astrophysics Data System (ADS)

Bray, Michaela; Liu, Jia; Abdulhamza, Ali; Bocklemann-Evans, Bettina

2013-04-01

Evapotranspiration is an important process in hydrology and is central to the analysis of water balances and water resource management. Significant water losses can occur in large drainage basins under semi arid climate conditions, moreover with the lack of measured data, the exact losses are hard to quantify. Since direct measurements for evapotranspiration are difficult to obtain it is common to estimate the process by using evapotranspiration models such as the Priestley-Taylor model, Shuttleworth -Wallace model and the FAO Penmann-Monteith. However these models depend on several atmospheric variables such as atmospheric pressure, wind speed, air temperature, net radiation and relative humidity. Some of these variables are also difficult to acquire from in-situ measurements; in addition these measurements provide local information which need to be interpolated to cover larger catchment areas over long time scales. Mesoscale Numerical Weather Prediction (NWP) modelling has become more accessible to the hydrometeorological community in recent years and is frequently used for modelling precipitation at the catchment scale. However these NWPs can also provide the atmospheric variables needed for evapotranspiration estimation at finer resolutions than can be attained from in situ measurements, offering a practical water resource tool. Moreover there is evidence that assimilation of real time observations can help improve the accuracy of mesoscale weather modelling which in turn would improve the overall evapotranspiration estimate. This study explores the effect of data assimilation in the Weather Research and Forecasting (WRF) model to derive evapotranspiration estimates for the Tigris water basin, Iraq. Two types of traditional observations, SYNOP and SOUND are assimilated by WRF-3DVAR.which contain surface and upper-level measurements of pressure, temperature, humidity and wind. The downscaled weather variables are used to determine evapostranspiration estimates

Evaluating gridded crop model simulations of evapotranspiration and irrigation using survey and remotely sensed data

NASA Astrophysics Data System (ADS)

Lopez Bobeda, J. R.

2017-12-01

The increasing use of groundwater for irrigation of crops has exacerbated groundwater sustainability issues faced by water limited regions. Gridded, process-based crop models have the potential to help farmers and policymakers asses the effects water shortages on yield and devise new strategies for sustainable water use. Gridded crop models are typically calibrated and evaluated using county-level survey data of yield, planting dates, and maturity dates. However, little is known about the ability of these models to reproduce observed crop evapotranspiration and water use at regional scales. The aim of this work is to evaluate a gridded version of the Decision Support System for Agrotechnology Transfer (DSSAT) crop model over the continental United States. We evaluated crop seasonal evapotranspiration over 5 arc-minute grids, and irrigation water use at the county level. Evapotranspiration was assessed only for rainfed agriculture to test the model evapotranspiration equations separate from the irrigation algorithm. Model evapotranspiration was evaluated against the Atmospheric Land Exchange Inverse (ALEXI) modeling product. Using a combination of the USDA crop land data layer (CDL) and the USGS Moderate Resolution Imaging Spectroradiometer Irrigated Agriculture Dataset for the United States (MIrAD-US), we selected only grids with more than 60% of their area planted with the simulated crops (corn, cotton, and soybean), and less than 20% of their area irrigated. Irrigation water use was compared against the USGS county level irrigated agriculture water use survey data. Simulated gridded data were aggregated to county level using USDA CDL and USGS MIrAD-US. Only counties where 70% or more of the irrigated land was corn, cotton, or soybean were selected for the evaluation. Our results suggest that gridded crop models can reasonably reproduce crop evapotranspiration at the country scale (RRMSE = 10%).

Translesion synthesis past equine estrogen-derived 2'-deoxyadenosine DNA adducts by human DNA polymerases eta and kappa.

PubMed

Yasui, Manabu; Laxmi, Y R Santosh; Ananthoju, Sreenivasa R; Suzuki, Naomi; Kim, Sung Yeon; Shibutani, Shinya

2006-05-16

Hormone replacement therapy (HRT) increases the risk of developing breast, ovarian, and endometrial cancers. Equilin and equilenin are the major components of the widely prescribed drug used for HRT. 4-Hydroxyequilenin (4-OHEN), a major metabolite of equilin and equilenin, promotes 4-OHEN-modified dC, dA, and dG DNA adducts. These DNA adducts were detected in breast tumor and adjacent normal tissues of several patients receiving HRT. We have recently found that the 4-OHEN-dC DNA adduct is a highly miscoding lesion generating C --> T transitions and C --> G transversions. To explore the mutagenic potential of another major 4-OHEN-dA adduct, site-specifically modified oligodeoxynucleotides containing a single diastereoisomer of 4-OHEN-dA (Pk-1, Pk-2, and Pk-3) were prepared by a postsynthetic method and used as DNA templates for primer extension reactions catalyzed by human DNA polymerase (pol) eta and kappa that are highly expressed in the reproductive organs. Primer extension catalyzed by pol eta or pol kappa occurred rapidly on the unmodified template to form fully extended products. With the major 4-OHEN-dA-modified templates (Pk-2 and Pk-3), primer extension was retarded prior to the lesion and opposite the lesion; a fraction of the primers was extended past the lesion. Steady-state kinetic studies with pol eta and pol kappa indicated that dTMP, the correct base, was preferentially incorporated opposite the 4-OHEN-dA lesion. In addition, pol eta and pol kappa bypassed the lesion by incorporating dAMP and dCMP, respectively, opposite the lesion and extended past the lesion. The relative bypass frequency past the 4-OHEN-dA lesion with pol eta was at least 2 orders of magnitude higher than that observed with pol kappa. The bypass frequency past Pk-2 was more efficient than that past Pk-3. Thus, 4-OHEN-dA is a miscoding lesion generating A --> T transversions and A --> G transitions. The miscoding frequency and specificity of 4-OHEN-dA varied depending on the

Evaluation of the 29-km Eta Model. Part 1; Objective Verification at Three Selected Stations

NASA Technical Reports Server (NTRS)

Nutter, Paul A.; Manobianco, John; Merceret, Francis J. (Technical Monitor)

1998-01-01

This paper describes an objective verification of the National Centers for Environmental Prediction (NCEP) 29-km eta model from May 1996 through January 1998. The evaluation was designed to assess the model's surface and upper-air point forecast accuracy at three selected locations during separate warm (May - August) and cool (October - January) season periods. In order to enhance sample sizes available for statistical calculations, the objective verification includes two consecutive warm and cool season periods. Systematic model deficiencies comprise the larger portion of the total error in most of the surface forecast variables that were evaluated. The error characteristics for both surface and upper-air forecasts vary widely by parameter, season, and station location. At upper levels, a few characteristic biases are identified. Overall however, the upper-level errors are more nonsystematic in nature and could be explained partly by observational measurement uncertainty. With a few exceptions, the upper-air results also indicate that 24-h model error growth is not statistically significant. In February and August 1997, NCEP implemented upgrades to the eta model's physical parameterizations that were designed to change some of the model's error characteristics near the surface. The results shown in this paper indicate that these upgrades led to identifiable and statistically significant changes in forecast accuracy for selected surface parameters. While some of the changes were expected, others were not consistent with the intent of the model updates and further emphasize the need for ongoing sensitivity studies and localized statistical verification efforts. Objective verification of point forecasts is a stringent measure of model performance, but when used alone, is not enough to quantify the overall value that model guidance may add to the forecast process. Therefore, results from a subjective verification of the meso-eta model over the Florida peninsula are

Comparison of Bowen-ratio, eddy-correlation, and weighing-lysimeter evapotranspiration for two sparse-canopy sites in eastern Washington

USGS Publications Warehouse

Tomlinson, S.A.

1996-01-01

This report compares evapotranspiration estimated with the Bowen-ratio and eddy-correlation methods with evapotranspiration measured by weighing lysimeters for two sparse-canopy sites in eastern Washington. The sites are located in a grassland area (grass lysimeter site) and a sagbrush- covered area (sage lysimeter site) on the Arid Lands Ecology Reserve in Benton County, Washington. Lysimeter data were collected at the sites from August 1990 to November 1994. Bowen-ratio data were collected for varying periods from May 1993 to November 1994. Additional Bowen-ratio data without interchanging air- temperature and vapor-pressure sensors to remove sensor bias (fixed-sensor system) were collected from October 1993 to June 1994. Eddy-correlation data were collected at the grass lysimeter site from March to April 1994, and at the sage lysimeter site from April to May 1994. The comparisons of evapotranspiration determined by the various methods differed considerably, depending on the periods of record being compared and the sites being analyzed. The year 1993 was very wet, with about 50 percent more precipitation than average; 1994 was a very dry year, with only about half the average precipitation. The study showed that on an annual basis, at least in 1994, Bowen-ratio evapotranspiration closely matched lysimeter evapotranspiration. In 1993, Bowen-ratio and lysimeter evapotranspiration comparisons were variable. Evapotranspiration estimated with the Bowen-ratio method averaged 5 percent more than evapotranspiration measured by lysimeters at the grass lysimeter site from October 1993 to November 1994, and 3 percent less than lysimeters at the sage lysimeter site from November 1993 to October 1994. From March 24 to April 5, 1994, at the grass lysimeter site, the Bowen-ratio method estimated 11 percent less, the Bowen-ratio method utilizing the fixed sensor system about 7 percent more, and the eddy-correlation method about 28 percent less evapotranspiration than the

Syntheses, spectroscopic characterizations, and X-ray structures of new Os({eta}{sup 2}-H{sub 2}) compounds containing azole ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esteruelas, M.A.; Lahoz, F.J.; Oro, L.A.

1994-02-16

The dihydrido-dichloro complex OsH{sub 2}Cl{sub 2}(P-i-Pr{sub 3}){sub 2} (1) reacts with 2,2{prime}-biimidazole (H{sub 2}bim) to give the dihydrogen derivative [OsCl({eta}{sup 2}-H{sub 2})(H{sub 2}bim)(P-i-Pr{sub 3}){sub 2}]Cl (2). The molecular structure of 2 has been determined by X-ray investigation. 2 crystallizes with a dichloromethane molecule in the triclinic space group Pl. The coordination geometry around the osmium center can be rationalized as a distorted octahedron with the two phosphine ligands disposed mutually trans. The remaining coordination sites of the octahedron are occupied by the dihydrogen ligand, the chloride atom, and by two nitrogen atoms of the chelate 2,2{prime}-biimidazole ligand. One of themore » two acidic NH groups of the 2,2{prime}-biimidazole ligand of 2 can be deprotonated by NaBH{sub 4} to give [OsCl({eta}{sup 2}-H{sub 2})(Hbim)(P-i-Pr{sub 3}){sub 2}] (3). Similarly the 2,2{prime}-biimidazole ligand of 2 is deprotonated by dimers of the type [M({mu}-OMe)(diolefin)]{sub 2} to form the heterobimetallic compounds [(P-i-Pr{sub 3}){sub 2}({eta}{sup 2}-H{sub 2})ClOs({mu}-Hbim)IrCl(COD)] (5), and [(P-i-Pr{sub 3}){sub 2}({eta}{sup 2}-H{sub 2})ClOs({mu}-Hbim)IrCl(TFB)] (TFG = tetrafluorobenzobarrelene, 6). The addition of pyrazole to 1 leads to the complex trans-dichloro-[OsCl{sub 2}({eta}{sup 2}-H{sub 2})(Hpz)(P-i-Pr{sub 3}){sub 2}] (7), which is transformed into its isomer cis-dichloro-[OsCl{sub 2}({eta}{sup 2}-H{sub 2})(Hpz)(P-i-Pr{sub 3}){sub 2}] (8) by stirring in hexane at 60 {degrees}C. The coordination geometry around the osmium center could be described as based on a distorted octahedron with the two phosphine ligands occuping the apical positions. The equatorial plane is formed by the dihydrogen and the pyrazole ligands mutually cis-disposed and the two chloride atoms are also cis-disposed.« less

Eta Carinae's Thermal X-Ray Tail Measured with XMM-Newton and NuStar

NASA Technical Reports Server (NTRS)

Hamaguchi, Kenji; Corcoran, Michael F.; Gull, Theodore R.; Takahashi, Hiromitsu; Grefenstette, Brian; Yuasa, Takayuki; Stuhlinger, Martin; Russell, Christopher; Moffat, Anthony F. J.; Madura, Thomas

2016-01-01

The evolved, massive highly eccentric binary system, Car, underwent a periastron passage in the summer of 2014. We obtained two coordinated X-ray observations with XMM-Newton and NuSTAR during the elevated X-ray flux state and just before the X-ray minimum flux state around this passage. These NuSTAR observations clearly detected X-ray emission associated with eta Car extending up to approx. 50 keV for the first time. The NuSTAR spectrum above 10 keV can be fit with the bremsstrahlung tail from a kT approx. 6 keV plasma. This temperature is delta kT 2 keV higher than those measured from the iron K emission line complex, if the shocked gas is in collisional ionization equilibrium. This result may suggest that the companion star's pre-shock wind velocity is underestimated. The NuSTAR observation near the X-ray minimum state showed a gradual decline in the X-ray emission by 40% at energies above 5 keV in a day, the largest rate of change of the X-ray flux yet observed in individual eta Car observations. The column density to the hardest emission component, N(sub H) approx. 10(exp24) H cm(exp-2), marked one of the highest values ever observed for eta Car, strongly suggesting the increased obscuration of the wind-wind colliding X-ray emission by the thick primary stellar wind prior to superior conjunction. Neither observation detected the power-law component in the extremely hard band that INTEGRAL and Suzaku observed prior to 2011. The power-law source might have faded before these observations.

Partitioning understory evapotranspiration in semi-arid ecosystems in Namibia using the isotopic composition of water vapour

NASA Astrophysics Data System (ADS)

de Blécourt, Marleen; Gaj, Marcel; Holtorf, Kim-Kirsten; Gröngröft, Alexander; Brokate, Ralph; Himmelsbach, Thomas; Eschenbach, Annette

2016-04-01

In dry environments with a sparse vegetation cover, understory evapotranspiration is a major component of the ecosystem water balance. Consequently, knowledge on the size of evapotranspiration fluxes and the driving factors is important for our understanding of the hydrological cycle. Understory evapotranspiration is made up of soil evaporation and plant transpiration. Soil evaporation can be measured directly from patches free of vegetation. However, when understory vegetation is present distinguishing between soil evaporation and plant transpiration is challenging. In this study, we aim to partition understory evapotranspiration based on an approach that combines the measurements of water-vapour fluxes using the closed chamber method with measurements of the isotopic composition of water vapour. The measurements were done in the framework of SASSCAL (Southern African Science Service Centre for Climate Change and Adaptive Land Management). The study sites were located in three different semi-arid ecosystems in Namibia: thornbush savanna, Baikiaea woodland and shrubland. At each site measurements were done under tree canopies as well as at unshaded areas between the canopies. We measured evaporation from the bare soil and evapotranspiration from patches covered with herbaceous species and shrubs using a transparent chamber connected with an infrared gas analyser (LI-8100A, LICOR Inc.). The stable isotope composition of water vapour inside the chamber and depth profiles of soil water stable isotopes were determined in-situ using a tuneable off-axis integrated cavity output spectroscope (OA-ICOS, Los Gatos Research, DLT 100). Xylem samples were extracted using the cryogenic vacuum extraction method and the isotopic composition of the extracted water was measured subsequently with a cavity-ring-down spectrometer (CRDS L2120-i, Picarro Inc.). We will present the quantified fluxes of understory evapotranspiration measured in the three different ecosystems, show the

Assessment of Evapotranspiration and Soil Moisture Content Across Different Scales of Observation.

PubMed

Verstraeten, Willem W; Veroustraete, Frank; Feyen, Jan

2008-01-09

The proper assessment of evapotranspiration and soil moisture content arefundamental in food security research, land management, pollution detection, nutrient flows,(wild-) fire detection, (desert) locust, carbon balance as well as hydrological modelling; etc.This paper takes an extensive, though not exhaustive sample of international scientificliterature to discuss different approaches to estimate land surface and ecosystem relatedevapotranspiration and soil moisture content. This review presents:(i) a summary of the generally accepted cohesion theory of plant water uptake andtransport including a shortlist of meteorological and plant factors influencing planttranspiration;(ii) a summary on evapotranspiration assessment at different scales of observation (sapflow,porometer, lysimeter, field and catchment water balance, Bowen ratio,scintillometer, eddy correlation, Penman-Monteith and related approaches);(iii) a summary on data assimilation schemes conceived to estimate evapotranspirationusing optical and thermal remote sensing; and(iv) for soil moisture content, a summary on soil moisture retrieval techniques atdifferent spatial and temporal scales is presented.Concluding remarks on the best available approaches to assess evapotranspiration and soilmoisture content with and emphasis on remote sensing data assimilation, are provided.

X-ray Monitoring of eta Carinae: Variations on a Theme

NASA Technical Reports Server (NTRS)

Corcoran, M. F.

2004-01-01

We present monitoring observations by the Rossi X-ray Timing Explorer of the 2-10 keV X-ray emission from the supermassive star eta Carinae from 1996 through late 2003. These data cover more than one of the stellar variability cycles in temporal detail and include especially detailed monitoring through two X-ray minima. We compare the current X-ray minimum which began on June 29, 2003 to the previous X-ray minimum which began on December 15, 1997, and refine the X-ray period to 2024 days. We examine the variations in the X-ray spectrum with phase and with time, and also refine our understanding of the X-ray peaks which have a quasi-period of 84 days, with significant variation. Cycle-to-cycle differences are seen in the level of X-ray intensity and in the detailed variations of the X-ray flux on the rise to maximum just prior to the X-ray minimum. Despite these differences the similarities between the decline to minimum, the duration of the minimum, and correlated variations of the X-ray flux and other measures throughout the electromagnetic spectrum leave little doubt that that the X-ray variation is strictly periodic and produced by orbital motion as the wind from eta Carinae collides with the wind of an otherwise unseen companion.

Evaluating Evapotranspiration of a crop mosaic using microwave scintillometry

NASA Astrophysics Data System (ADS)

Cohard, J. M.; Barral, H.; Coulaud, C.; Mercier, B.; Cappelaere, B.; Demarty, J.; Arpin-Pont, F.; Bradford, J.

2017-12-01

Evapotranspiration (ET) remains particularly difficult to quantify, especially on complex and heterogeneous landscapes. Since the 1990s, scintillometry has been recognized as an accurate method to estimate turbulent fluxes at km² scales compatible with a satellite pixel or a hydrological model mesh. If optic scintillometry is today considered to be an accomplished technique to measure spatially integrated sensible heat fluxes and to indirectly derive ET through the energy budget equation, very few results have been published using microwave (MW) scintillometry to derive ET more directly at km² scales for lack of reliable instruments. The recent development of new sensors operating in the microwave (MW) range and the formalization of new algorithms for the treatment of turbulent correlations revive dreams of reliable and continuous measurements of the evapotranspiration at the landscape scale. This study presents a long term evapotranspiration series measured over a crop mosaic with the combination of two scintillometers (Two-wavelength method) operating, one in the near infra-red (BLS2000, Scintec) and the other in radiofrequencies (94GHz) developed in collaboration with the Rutherford Appleton Laboratory (UK). These instruments have been installed in the Critical Zone observatory Oracle, located east of Paris in the Seine Catchment, and have run continuously since May 2016. This first ET series shows the robustness of both the MW scintillometer and the two wavelength method in this context. Scintillation ET will be presented and compared with Eddy Covariance measurements carried out on different landcover types within the scintillometer footprint, with regard to the energy balance closure.

Projected Changes in Evapotranspiration Rates over Northeast Brazil

NASA Astrophysics Data System (ADS)

Costa, Alexandre; Guimarães, Sullyandro; Vasconcelos, Francisco, Jr.; Sales, Domingo; da Silva, Emerson

2015-04-01

Climate simulations were performed using a regional model (Regional Atmospheric Modeling System, RAMS 6.0) driven by data from one of the CMIP5 models (Hadley Centre Global Environmental Model, version 2 - Earth System, HadGEM2-ES) over two CORDEX domains (South America and Central America) for the heavy-emission scenario (RCP8.5). Potential evapotranspiraion data from the RCM and from the CMIP5 global models were analyzed over Northeast Brazil, a semiarid region with a short rainy season (usually February to May in its northern portion due to the seasonal shift of the Intertropical Convergence Zone) and over which droughts are frequent. Significant changes in the potential evapotranspiration were found, with most models showing a increasing trend along the 21st century, which are expected to alter the surface water budget, increasing the current water deficit (precipitation is currently much smaller than potential evapotranspiration). Based on the projections from the majority of the models, we expect important impacts over local agriculture and water resources over Northeast Brazil.

Ecosystem evapotranspiration: challenges in measurements, estimates, and modeling

Treesearch

Devendra Amatya; S. Irmak; P. Gowda; Ge Sun; J.E. Nettles; K.R. Douglas-Mankin

2016-01-01

Evapotranspiration (ET) processes at the leaf to landscape scales in multiple land uses have important controls and feedbacks for local, regional, and global climate and water resource systems. Innovative methods, tools, and technologies for improved understanding and quantification of ET and crop water use are critical for adapting more effective management strategies...

Annual evapotranspiration of a forested wetland watershed, SC

Treesearch

Devendra M. Amatya; Carl Trettin

2007-01-01

In this study, hydro-meteorological data collected from 1 964 to 1 9 76 on an approximately 5, 000 ha predominantly forested coastal watershed (Turkey Creek) at the Francis Marion National Forest near Charleston, SC were analyzed to estimate annual evapotranspiration (E T) using four different empirical methods. The first one, reported by Zhang et a/. (2001), that...

Forest evapotranspiration: measurements and modeling at multiple scales

Treesearch

Ge Sun; J-C. Domec; Devendra Amatya

2016-01-01

Compared with traditional engineering hydrology, forest hydrology has a relatively long history of studying the effects of vegetation in regulating streamflow through evapotranspiration (Hewlett, 1982; Swank and Crossley, 1988; Andreassian, 2004; Brown et al., 2005; Amatya et al., 2011, 2015, 2016; Sun et al., 2011b; Vose et al., 2011). It is estimated that more than...

Translesion synthesis past equine estrogen-derived 2'-deoxycytidine DNA adducts by human DNA polymerases eta and kappa.

PubMed

Suzuki, Naomi; Yasui, Manabu; Santosh Laxmi, Y R; Ohmori, Haruo; Hanaoka, Fumio; Shibutani, Shinya

2004-09-07

Estrogen replacement therapy (ERT), composed of equilenin, is associated with increased risk of breast, ovarian, and endometrial cancers. Several diastereoisomers of unique dC and dA DNA adducts were derived from 4-hydroxyequilenin (4-OHEN), a metabolite of equilenin, and have been detected in women receiving ERT. To explore the miscoding property of 4-OHEN-dC adduct, site-specifically modified oligodeoxynucleotides (Pk-1, Pk-2, Pk-3, and Pk-4) containing a single diastereoisomer of 4-OHEN-dC were prepared by a postsynthetic method. Among them, major 4-OHEN-dC-modified oligodeoxynucleotides (Pk-3 and Pk-4) were used to prepare the templates for primer extension reactions catalyzed by DNA polymerase (pol) alpha, pol eta, and pol kappa. Primer extension was retarded one base prior to the lesion and opposite the lesion; stronger blockage was observed with pol alpha, while with human pol eta or pol kappa, a fraction of the primers was extended past the lesion. Steady-state kinetic studies showed that both pol kappa and pol eta inserted dCMP and dAMP opposite the 4-OHEN-dC and extended past the lesion. Never or less-frequently, dGMP, the correct base, was inserted opposite the lesion. The relative bypass frequency past the 4-OHEN-dC lesion with pol eta was at least 3 orders of magnitude higher than that for pol kappa, as observed for primer extension reactions. The bypass frequency past the dA.4-OHEN-dC adduct in Pk-4 was 2 orders of magnitude more efficient than that past the adduct in Pk-3. Thus, 4-OHEN-dC is a highly miscoding lesion capable of generating C --> T transitions and C --> G transversions. The miscoding frequency and specificity of 4-OHEN-dC were strikingly influenced by the adduct stereochemistry and DNA polymerase used.

Spatial and temporal evapotranspiration trends after wildfire in semi-arid landscapes

NASA Astrophysics Data System (ADS)

Poon, Patrick K.; Kinoshita, Alicia M.

2018-04-01

In recent years climate change and other anthropogenic factors have contributed to increased wildfire frequency and size in western United States forests. This research focuses on the evaluation of spatial and temporal changes in evapotranspiration (ET) following the 2011 Las Conchas Fire in New Mexico (USA) using the Operational Simplified Surface Energy Balance Model (SSEBop ET). Evapotranspiration is coupled with soil burn severity and analyzed for 16 watersheds for water years 2001-2014. An average annual decrease of 120 mm of ET is observed within the regions affected by the Las Conchas Fire, and conifers were converted to grassland a year after the fire. On average, the post-fire annual ET in high, moderate, and low burn severity is lower than pre-fire ET by approximately 103-352 mm, 97-304 mm, and 91-268 mm, respectively. The ratio of post-fire evapotranspiration to precipitation (ET/P) is statistically different from pre-fire conditions (α = 0.05) in nine of the watersheds. The largest decrease in ET is approximately 13-57 mm per month and is most prominent during the summer (April to September). The observed decrease in ET contributes to our understanding of changes in water yield following wildfires, which is of interest for accurately modeling and predicting hydrologic processes in semi-arid landscapes.