Numerical Simulations for Landing Gear Noise Generation and Radiation
NASA Technical Reports Server (NTRS)
Morris, Philip J.; Long, Lyle N.
2002-01-01
Aerodynamic noise from a landing gear in a uniform flow is computed using the Ffowcs Williams -Hawkings (FW-H) equation. The time accurate flow data on the surface is obtained using a finite volume flow solver on an unstructured and. The Ffowcs Williams-Hawkings equation is solved using surface integrals over the landing gear surface and over a permeable surface away from the landing gear. Two geometric configurations are tested in order to assess the impact of two lateral struts on the sound level and directivity in the far-field. Predictions from the Ffowcs Williams-Hawkings code are compared with direct calculations by the flow solver at several observer locations inside the computational domain. The permeable Ffowcs Williams-Hawkings surface predictions match those of the flow solver in the near-field. Far-field noise calculations coincide for both integration surfaces. The increase in drag observed between the two landing gear configurations is reflected in the sound pressure level and directivity mainly in the streamwise direction.
We have developed a coupled land-surface and dry deposition model for realistic treatment of surface fluxes of heat, moisture, and chemical dry deposition within a comprehensive air quality modeling system. A new land-surface model (LSM) with explicit treatment of soil moisture...
Assessment and Enhancement of MERRA Land Surface Hydrology Estimates
NASA Technical Reports Server (NTRS)
Reichle, Rolf H.; Koster, Randal D.; deLannoy, Gabrielle J. M.; Forman, Barton A.; Liu, Qing; Mahanama, Sarith P. P.; Toure, Ally
2012-01-01
The Modern-Era Retrospective analysis for Research and Applications (MERRA) is a state-ofthe-art reanalysis that provides, in addition to atmospheric fields, global estimates of soil moisture, latent heat flux, snow, and runoff for 1979-present. This study introduces a supplemental and improved set of land surface hydrological fields ("MERRA-Land") generated by re-running a revised version of the land component of the MERRA system. Specifically, the MERRA-Land estimates benefit from corrections to the precipitation forcing with the Global Precipitation Climatology Project pentad product (version 2.1) and from revised parameter values in the rainfall interception model, changes that effectively correct for known limitations in the MERRA surface meteorological forcings. The skill (defined as the correlation coefficient of the anomaly time series) in land surface hydrological fields from MERRA and MERRA-Land is assessed here against observations and compared to the skill of the state-of-the-art ERA-Interim (ERA-I) reanalysis. MERRA-Land and ERA-I root zone soil moisture skills (against in situ observations at 85 US stations) are comparable and significantly greater than that of MERRA. Throughout the northern hemisphere, MERRA and MERRA-Land agree reasonably well with in situ snow depth measurements (from 583 stations) and with snow water equivalent from an independent analysis. Runoff skill (against naturalized stream flow observations from 18 US basins) of MERRA and MERRA-Land is typically higher than that of ERA-I. With a few exceptions, the MERRA-Land data appear more accurate than the original MERRA estimates and are thus recommended for those interested in using MERRA output for land surface hydrological studies.
Influence of Soil Heterogeneity on Mesoscale Land Surface Fluxes During Washita '92
NASA Technical Reports Server (NTRS)
Jasinski, Michael F.; Jin, Hao
1998-01-01
The influence of soil heterogeneity on the partitioning of mesoscale land surface energy fluxes at diurnal time scales is investigated over a 10(exp 6) sq km domain centered on the Little Washita Basin, Oklahoma, for the period June 10 - 18, 1992. The sensitivity study is carried out using MM5/PLACE, the Penn State/NCAR MM5 model enhanced with the Parameterization for Land-Atmosphere-Cloud Exchange or PLACE. PLACE is a one-dimensional land surface model possessing detailed plant and soil water physics algorithms, multiple soil layers, and the capacity to model subgrid heterogeneity. A series of 12-hour simulations were conducted with identical atmospheric initialization and land surface characterization but with different initial soil moisture and texture. A comparison then was made of the simulated land surface energy flux fields, the partitioning of net radiation into latent and sensible heat, and the soil moisture fields. Results indicate that heterogeneity in both soil moisture and texture affects the spatial distribution and partitioning of mesoscale energy balance. Spatial averaging results in an overprediction of latent heat flux, and an underestimation of sensible heat flux. In addition to the primary focus on the partitioning of the land surface energy, the modeling effort provided an opportunity to examine the issue of initializing the soil moisture fields for coupled three-dimensional models. For the present case, the initial soil moisture and temperature were determined from off-line modeling using PLACE at each grid box, driven with a combination of observed and assimilated data fields.
NASA Technical Reports Server (NTRS)
Bosilovich, Michael G.; Schubert, Siegfried; Molod, Andrea; Houser, Paul R.
1999-01-01
Land-surface processes in a data assimilation system influence the lower troposphere and must be properly represented. With the recent incorporation of the Mosaic Land-surface Model (LSM) into the GEOS Data Assimilation System (DAS), the detailed land-surface processes require strict validation. While global data sources can identify large-scale systematic biases at the monthly timescale, the diurnal cycle is difficult to validate. Moreover, global data sets rarely include variables such as evaporation, sensible heat and soil water. Intensive field experiments, on the other hand, can provide high temporal resolution energy budget and vertical profile data for sufficiently long periods, without global coverage. Here, we evaluate the GEOS DAS against several intensive field experiments. The field experiments are First ISLSCP Field Experiment (FIFE, Kansas, summer 1987), Cabauw (as used in PILPS, Netherlands, summer 1987), Atmospheric Radiation Measurement (ARM, Southern Great Plains, winter and summer 1998) and the Surface Heat Budget of the Arctic Ocean (SHEBA, Arctic ice sheet, winter and summer 1998). The sites provide complete surface energy budget data for periods of at least one year, and some periods of vertical profiles. This comparison provides a detailed validation of the Mosaic LSM within the GEOS DAS for a variety of climatologic and geographic conditions.
NASA Technical Reports Server (NTRS)
Reichle, Rolf; Koster, Randal; DeLannoy, Gabrielle; Forman, Barton; Liu, Qing; Mahanama, Sarith; Toure, Ally
2011-01-01
The Modern-Era Retrospective analysis for Research and Applications (MERRA) is a state-of-the-art reanalysis that provides. in addition to atmospheric fields. global estimates of soil moisture, latent heat flux. snow. and runoff for J 979-present. This study introduces a supplemental and improved set of land surface hydrological fields ('MERRA-Land') generated by replaying a revised version of the land component of the MERRA system. Specifically. the MERRA-Land estimates benefit from corrections to the precipitation forcing with the Global Precipitation Climatology Project pentad product (version 2.1) and from revised parameters in the rainfall interception model, changes that effectively correct for known limitations in the MERRA land surface meteorological forcings. The skill (defined as the correlation coefficient of the anomaly time series) in land surface hydrological fields from MERRA and MERRA-Land is assessed here against observations and compared to the skill of the state-of-the-art ERA-Interim reanalysis. MERRA-Land and ERA-Interim root zone soil moisture skills (against in situ observations at 85 US stations) are comparable and significantly greater than that of MERRA. Throughout the northern hemisphere, MERRA and MERRA-Land agree reasonably well with in situ snow depth measurements (from 583 stations) and with snow water equivalent from an independent analysis. Runoff skill (against naturalized stream flow observations from 15 basins in the western US) of MERRA and MERRA-Land is typically higher than that of ERA-Interim. With a few exceptions. the MERRA-Land data appear more accurate than the original MERRA estimates and are thus recommended for those interested in using '\\-tERRA output for land surface hydrological studies.
Two-Layer Variable Infiltration Capacity Land Surface Representation for General Circulation Models
NASA Technical Reports Server (NTRS)
Xu, L.
1994-01-01
A simple two-layer variable infiltration capacity (VIC-2L) land surface model suitable for incorporation in general circulation models (GCMs) is described. The model consists of a two-layer characterization of the soil within a GCM grid cell, and uses an aerodynamic representation of latent and sensible heat fluxes at the land surface. The effects of GCM spatial subgrid variability of soil moisture and a hydrologically realistic runoff mechanism are represented in the soil layers. The model was tested using long-term hydrologic and climatalogical data for Kings Creek, Kansas to estimate and validate the hydrological parameters. Surface flux data from three First International Satellite Land Surface Climatology Project Field Experiments (FIFE) intensive field compaigns in the summer and fall of 1987 in central Kansas, and from the Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) in Brazil were used to validate the mode-simulated surface energy fluxes and surface temperature.
Kelly Elder; Don Cline; Glen E. Liston; Richard Armstrong
2009-01-01
A field measurement program was undertaken as part NASA's Cold Land Processes Experiment (CLPX). Extensive snowpack and soil measurements were taken at field sites in Colorado over four study periods during the two study years (2002 and 2003). Measurements included snow depth, density, temperature, grain type and size, surface wetness, surface roughness, and...
NASA Technical Reports Server (NTRS)
Liang, XU; Lettenmaier, Dennis P.; Wood, Eric F.; Burges, Stephen J.
1994-01-01
A generalization of the single soil layer variable infiltration capacity (VIC) land surface hydrological model previously implemented in the Geophysical Fluid Dynamics Laboratory (GFDL) general circulation model (GCM) is described. The new model is comprised of a two-layer characterization of the soil column, and uses an aerodynamic representation of the latent and sensible heat fluxes at the land surface. The infiltration algorithm for the upper layer is essentially the same as for the single layer VIC model, while the lower layer drainage formulation is of the form previously implemented in the Max-Planck-Institut GCM. The model partitions the area of interest (e.g., grid cell) into multiple land surface cover types; for each land cover type the fraction of roots in the upper and lower zone is specified. Evapotranspiration consists of three components: canopy evaporation, evaporation from bare soils, and transpiration, which is represented using a canopy and architectural resistance formulation. Once the latent heat flux has been computed, the surface energy balance is iterated to solve for the land surface temperature at each time step. The model was tested using long-term hydrologic and climatological data for Kings Creek, Kansas to estimate and validate the hydrological parameters, and surface flux data from three First International Satellite Land Surface Climatology Project Field Experiment (FIFE) intensive field campaigns in the summer-fall of 1987 to validate the surface energy fluxes.
Modeling surface energy fluxes from a patchwork of fields with different soils and crops
NASA Astrophysics Data System (ADS)
Klein, Christian; Thieme, Christoph; Heinlein, Florian; Priesack, Eckart
2017-04-01
Agroecosystems are a dominant terrestrial land-use on planet earth and cover about 36% of the ice-free surface (12% pasture, 26% agriculture) [Foley2011]. Within this land use type, management practices vary strongly due to climate, cultural preferences, degree of industrialization, soil properties, crop rotations, field sizes, degree of land use sustainability, water availability, sowing and harvest dates, tillage, etc. These management practices influence abiotic environmental factors like water flow and heat transport within the ecosystem leading to changes of land surface fluxes. The relevance of vegetation (e.g. crops), ground cover, and soil properties to the moisture and energy exchanges between the land surface and the atmosphere is well known [McPherson 2007], but the impact of vegetation growth dynamics on energy fluxes is only partly understood [Gayler et al. 2014]. Thus, the structure of turbulence and the albedo evolve during the cropping period and large variations of heat can be measured on the field scale [Aubinet2012]. One issue of local distributed mixture of different land use is the measurement process which makes it challenging to evaluate simulations. Unfortunately, for meteorological flux-measurements like the Flux-Gradient or the Eddy Covariance (EC) method, comparability with simulations only exists in the ideal case, where fields have to be completely uniform in land use and flat within the reach of the footprint. Then a model with one specific land use would have the same underlying source area as the measurement. An elegant method to avoid the shortcoming of grid cell resolution is the so called mixed approach, which was recently implemented into the ecosystem model framework Expert-N [Biernath et al. 2013]. The aim of this study was to analyze the impact of the characteristics of five managed field plots, planted with winter wheat, potato and maize on the near surface soil moistures and on the near surface energy flux exchanges of the soil-plant-atmosphere interface. The simulated energy fluxes were compared with eddy flux tower measurements between the respective fields at the research farm Scheyern, North-West of Munich, Germany. These simulations were done by coupling the ecosystem model Expert-N to an analytical footprint model [Mauder & Foken 2011] . The coupled model system has the ability to calculate the mixing ratio of the surface energy fluxes at the flux tower position. The approach accounts for the temporarily and spatially changing contributions of the patchwork of environmental land surface conditions (land use, management, soil properties) which influence the energy flux tower measurements due to the footprint dynamics. The statistical evaluation between simulation and measurements showed that the mixed approach improved the comparability in most cases. Furthermore, the management impact on single patches can be clearly detected, both in the measurements and the simulation. We conclude that reasonable simulations of energy and matter fluxes can be obtained if the heterogeneity of the land surfaces is taken into account.
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.
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.
Large-scale experimental technology with remote sensing in land surface hydrology and meteorology
NASA Technical Reports Server (NTRS)
Brutsaert, Wilfried; Schmugge, Thomas J.; Sellers, Piers J.; Hall, Forrest G.
1988-01-01
Two field experiments to study atmospheric and land surface processes and their interactions are summarized. The Hydrologic-Atmospheric Pilot Experiment, which tested techniques for measuring evaporation, soil moisture storage, and runoff at scales of about 100 km, was conducted over a 100 X 100 km area in France from mid-1985 to early 1987. The first International Satellite Land Surface Climatology Program field experiment was conducted in 1987 to develop and use relationships between current satellite measurements and hydrologic, climatic, and biophysical variables at the earth's surface and to validate these relationships with ground truth. This experiment also validated surface parameterization methods for simulation models that describe surface processes from the scale of vegetation leaves up to scales appropriate to satellite remote sensing.
New and Improved GLDAS and NLDAS Data Sets and Data Services at HDISC/NASA
NASA Technical Reports Server (NTRS)
Rui, Hualan; Beaudoing, Hiroko Kato; Mocko, David M.; Rodell, Matthew; Teng, William L.; Vollmer. Bruce
2010-01-01
Terrestrial hydrological variables are important in global hydrology, climate, and carbon cycle studies. Generating global fields of these variables, however, is still a challenge. The goal of a land data assimilation system (LDAS)is to ingest satellite-and ground-based observational data products, using advanced land surface modeling and data assimilation techniques, in order to generate optimal fields of land surface states and fluxes data and, thereby, facilitate hydrology and climate modeling, research, and forecast.
DISAGGREGATION OF GOES LAND SURFACE TEMPERATURES USING SURFACE EMISSIVITY
USDA-ARS?s Scientific Manuscript database
Accurate temporal and spatial estimation of land surface temperatures (LST) is important for modeling the hydrological cycle at field to global scales because LSTs can improve estimates of soil moisture and evapotranspiration. Using remote sensing satellites, accurate LSTs could be routine, but unfo...
[A review on research of land surface water and heat fluxes].
Sun, Rui; Liu, Changming
2003-03-01
Many field experiments were done, and soil-vegetation-atmosphere transfer(SVAT) models were stablished to estimate land surface heat fluxes. In this paper, the processes of experimental research on land surface water and heat fluxes are reviewed, and three kinds of SVAT model(single layer model, two layer model and multi-layer model) are analyzed. Remote sensing data are widely used to estimate land surface heat fluxes. Based on remote sensing and energy balance equation, different models such as simplified model, single layer model, extra resistance model, crop water stress index model and two source resistance model are developed to estimate land surface heat fluxes and evapotranspiration. These models are also analyzed in this paper.
NASA Astrophysics Data System (ADS)
Fiener, P.; Auerswald, K.; van Oost, K.
2009-04-01
In many landscapes, land use creates a complex pattern in addition to the patterns resulting from soil, topography and rain. Despite the static layout of fields, a spatio-temporally highly variable situation regarding the surface runoff and erosion processes results from the asynchronous seasonal variation associated with different land uses. While the behaviour of individual land-uses and their seasonal variation is analyzed in many studies, the spatio-temporal interaction related to this pattern is rarely studied despite its crucial influence on hydrological and geomorphic response of catchments. The difficulty in studying such interactions mainly results from the fact that it is impossible to set up a replicated experiment on the landscape scale. The purpose of this review is to present the advances made thus far in quantifying the effects of patchiness of land use and management on surface runoff response in agricultural catchments. We will focus on the effects of spatio-temporal patterns in land use patches on hydraulic connectivity between patches and within catchments. This will include the temporal patterns in land management affecting infiltration, surface roughness and hence runoff concentration within single fields or land use patches insofar as these effects must be known to evaluate the combined effect of patch behaviour in space and time on catchment connectivity and surface runoff. Surface runoff effects of patchiness and connectivity between patches or within a catchment, can either be addressed by modelling studies or by comprehensive catchment field measurements, e.g. paired-watershed experiments or landscape scale studies on different scales. This limits our review to studies at the scale of small catchments < 10 km², where the time constant of the network (i.e. travel time through it) is smaller than the infiltration phase. Despite this limitation, these small catchments are important as they constitute 2/3 of the total surface of large water drainage networks.
Updating representation of land surface-atmosphere feedbacks in airborne campaign modeling analysis
NASA Astrophysics Data System (ADS)
Huang, M.; Carmichael, G. R.; Crawford, J. H.; Chan, S.; Xu, X.; Fisher, J. A.
2017-12-01
An updated modeling system to support airborne field campaigns is being built at NASA Ames Pleiades, with focus on adjusting the representation of land surface-atmosphere feedbacks. The main updates, referring to previous experiences with ARCTAS-CARB and CalNex in the western US to study air pollution inflows, include: 1) migrating the WRF (Weather Research and Forecasting) coupled land surface model from Noah to improved/more complex models especially Noah-MP and Rapid Update Cycle; 2) enabling the WRF land initialization with suitably spun-up land model output; 3) incorporating satellite land cover, vegetation dynamics, and soil moisture data (i.e., assimilating Soil Moisture Active Passive data using the ensemble Kalman filter approach) into WRF. Examples are given of comparing the model fields with available aircraft observations during spring-summer 2016 field campaigns taken place at the eastern side of continents (KORUS-AQ in South Korea and ACT-America in the eastern US), the air pollution export regions. Under fair weather and stormy conditions, air pollution vertical distributions and column amounts, as well as the impact from land surface, are compared. These help identify challenges and opportunities for LEO/GEO satellite remote sensing and modeling of air quality in the northern hemisphere. Finally, we briefly show applications of this system on simulating Australian conditions, which would explore the needs for further development of the observing system in the southern hemisphere and inform the Clean Air and Urban Landscapes (https://www.nespurban.edu.au) modelers.
Simultaneous inversion of multiple land surface parameters from MODIS optical-thermal observations
NASA Astrophysics Data System (ADS)
Ma, Han; Liang, Shunlin; Xiao, Zhiqiang; Shi, Hanyu
2017-06-01
Land surface parameters from remote sensing observations are critical in monitoring and modeling of global climate change and biogeochemical cycles. Current methods for estimating land surface variables usually focus on individual parameters separately even from the same satellite observations, resulting in inconsistent products. Moreover, no efforts have been made to generate global products from integrated observations from the optical to Thermal InfraRed (TIR) spectrum. Particularly, Middle InfraRed (MIR) observations have received little attention due to the complexity of the radiometric signal, which contains both reflected and emitted radiation. In this paper, we propose a unified algorithm for simultaneously retrieving six land surface parameters - Leaf Area Index (LAI), Fraction of Absorbed Photosynthetically Active Radiation (FAPAR), land surface albedo, Land Surface Emissivity (LSE), Land Surface Temperature (LST), and Upwelling Longwave radiation (LWUP) by exploiting MODIS visible-to-TIR observations. We incorporate a unified physical radiative transfer model into a data assimilation framework. The MODIS visible-to-TIR time series datasets include the daily surface reflectance product and MIR-to-TIR surface radiance, which are atmospherically corrected from the MODIS data using the Moderate Resolution Transmittance program (MODTRAN, ver. 5.0). LAI was first estimated using a data assimilation method that combines MODIS daily reflectance data and a LAI phenology model, and then the LAI was input to the unified radiative transfer model to simulate spectral surface reflectance and surface emissivity for calculating surface broadband albedo and emissivity, and FAPAR. LST was estimated from the MIR-TIR surface radiance data and the simulated emissivity, using an iterative optimization procedure. Lastly, LWUP was estimated using the LST and surface emissivity. The retrieved six parameters were extensively validated across six representative sites with different biome types, and compared with MODIS, GLASS, and GlobAlbedo land surface products. The results demonstrate that the unified inversion algorithm can retrieve temporally complete and physically consistent land surface parameters, and provides more accurate estimates of surface albedo, LST, and LWUP than existing products, with R2 values of 0.93 and 0.62, RMSE of 0.029 and 0.037, and BIAS values of 0.016 and 0.012 for the retrieved and MODIS albedo products, respectively, compared with field albedo measurements; R2 values of 0.95 and 0.93, RMSE of 2.7 and 4.2 K, and BIAS values of -0.6 and -2.7 K for the retrieved and MODIS LST products, respectively, compared with field LST measurements; and R2 values of 0.93 and 0.94, RMSE of 18.2 and 22.8 W/m2, and BIAS values of -2.7 and -14.6 W/m2 for the retrieved and MODIS LWUP products, respectively, compared with field LWUP measurements.
Exploration of scaling effects on coarse resolution land surface phenology
USDA-ARS?s Scientific Manuscript database
A great number of land surface phenoloy (LSP) data have been produced from various coarse resolution satellite datasets and detection algorithms across regional and global scales. Unlike field- measured phenological events which are quantitatively defined with clear biophysical meaning, current LSP ...
2014-11-03
Rob Mueller, NASA senior technologist in the Surface Systems Office in Kennedy Space Center's Engineering and Technology Directorate, demonstrates the Regolith Advanced Surface System Operations Robot, or RASSOR, during a media event at Kennedy's automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility. The event was held to announce Moon Express Inc., of Moffett Field, California is selected to utilize Kennedy facilities for NASA's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST.
USDA-ARS?s Scientific Manuscript database
Thermal-infrared (TIR) remote sensing of land surface temperature (LST) provides valuable information for quantifying root-zone water availability, evapotranspiration (ET) and crop condition as well as providing useful information for constraining prognostic land surface models. This presentation d...
Wagner, Chad R.; Fitzgerald, Sharon A.; McSwain, Kristen Bukowski; Harden, Stephen L.; Gurley, Laura N.; Rogers, Shane W.
2015-01-01
The data, analysis, and conclusions associated with this study can be used by regulatory agencies, resource managers, and wastewater-treatment operators to (1) better understand the quantity and characteristics of nutrients, bacteria, metals, and contaminants of emerging concern that are transported away from biosolids land-application fields to surface water and groundwater under current regulations for the purposes of establishing effective total maximum daily loads (TMDLs) and restoring impaired water resources, (2) assess how well existing regulations protect waters of the State and potentially recommend effective changes to regulations or land-application procedures, and (3) establish a framework for developing guidance on effective techniques for monitoring and regulatory enforcement of permitted biosolids land-application fields.
NASA Astrophysics Data System (ADS)
Tong, Xiao Xia; Lai Cui, Yuan; Chen, Man Yu; Hu, Bo; Xu, Wen Sheng
2018-05-01
The Er yuan watershed of Er hai district is chosen as the research area, the law of runoff and sediment and non-point source nitrogen and phosphorus discharges under different land uses during 2001 to 2014 are simulated based on SWAT model. Results of simulation indicate that the order of total runoff yield of different land use type from high to low is grassland, paddy fields, dry land. Specifically, the order of surface runoff yield from high to low is paddy fields, dry land, grassland, the order of lateral runoff yield from high to low is paddy fields, dry land, grassland, the order of groundwater runoff yield from high to low is grassland, paddy fields, dry land. The orders of sediment and nitrogen and phosphorus yield per unit area of different land use type are the same, grassland> paddy fields> dry land. It can be seen, nitrogen and phosphorus discharges from paddy fields and dry land are the main sources of agricultural non-point pollution of the irrigated area. Therefore, reasonable field management measures which can decrease the discharge of nitrogen and phosphorus of paddy fields and dry land are the key to agricultural non-point source pollution prevention and control.
Land subsidence near oil and gas fields, Houston, Texas.
Holzer, T.L.; Bluntzer, R.L.
1984-01-01
Subsidence profiles across 29 oil and gas fields in the 12 200 km2 Houston, Texas, regional subsidence area, which is caused by the decline of ground-water level, suggest that the contribution of petroleum withdrawal to local land subsidence is small. In addition to land subsidence, faults with an aggregate length of more than 240 km have offset the land surface in historical time. Natural geologic deformation, ground-water pumping, and petroleum withdrawal have all been considered as potential causes of the historical offset across these faults. The minor amount of localized land subsidence associated with oil and gas fields, suggests that petroleum withdrawal is not a major cause of the historical faulting. -from Authors
High-resolution surface analysis for extended-range downscaling with limited-area atmospheric models
NASA Astrophysics Data System (ADS)
Separovic, Leo; Husain, Syed Zahid; Yu, Wei; Fernig, David
2014-12-01
High-resolution limited-area model (LAM) simulations are frequently employed to downscale coarse-resolution objective analyses over a specified area of the globe using high-resolution computational grids. When LAMs are integrated over extended time frames, from months to years, they are prone to deviations in land surface variables that can be harmful to the quality of the simulated near-surface fields. Nudging of the prognostic surface fields toward a reference-gridded data set is therefore devised in order to prevent the atmospheric model from diverging from the expected values. This paper presents a method to generate high-resolution analyses of land-surface variables, such as surface canopy temperature, soil moisture, and snow conditions, to be used for the relaxation of lower boundary conditions in extended-range LAM simulations. The proposed method is based on performing offline simulations with an external surface model, forced with the near-surface meteorological fields derived from short-range forecast, operational analyses, and observed temperatures and humidity. Results show that the outputs of the surface model obtained in the present study have potential to improve the near-surface atmospheric fields in extended-range LAM integrations.
Impacts of surface gold mining on land use systems in Western Ghana.
Schueler, Vivian; Kuemmerle, Tobias; Schröder, Hilmar
2011-07-01
Land use conflicts are becoming increasingly apparent from local to global scales. Surface gold mining is an extreme source of such a conflict, but mining impacts on local livelihoods often remain unclear. Our goal here was to assess land cover change due to gold surface mining in Western Ghana, one of the world's leading gold mining regions, and to study how these changes affected land use systems. We used Landsat satellite images from 1986-2002 to map land cover change and field interviews with farmers to understand the livelihood implications of mining-related land cover change. Our results showed that surface mining resulted in deforestation (58%), a substantial loss of farmland (45%) within mining concessions, and widespread spill-over effects as relocated farmers expand farmland into forests. This points to rapidly eroding livelihood foundations, suggesting that the environmental and social costs of Ghana's gold boom may be much higher than previously thought.
Barton, C Michael; Ullah, Isaac I; Bergin, Sean
2010-11-28
The evolution of Mediterranean landscapes during the Holocene has been increasingly governed by the complex interactions of water and human land use. Different land-use practices change the amount of water flowing across the surface and infiltrating the soil, and change water's ability to move surface sediments. Conversely, water amplifies the impacts of human land use and extends the ecological footprint of human activities far beyond the borders of towns and fields. Advances in computational modelling offer new tools to study the complex feedbacks between land use, land cover, topography and surface water. The Mediterranean Landscape Dynamics project (MedLand) is building a modelling laboratory where experiments can be carried out on the long-term impacts of agropastoral land use, and whose results can be tested against the archaeological record. These computational experiments are providing new insights into the socio-ecological consequences of human decisions at varying temporal and spatial scales.
Aeroacoustic Analysis of a Simplified Landing Gear
NASA Technical Reports Server (NTRS)
Lockard, David P.; Khorrami, Mehdi, R.; Li, Fei
2004-01-01
A hybrid approach is used to investigate the noise generated by a simplified landing gear without small scale parts such as hydraulic lines and fasteners. The Ffowcs Williams and Hawkings equation is used to predict the noise at far-field observer locations from flow data provided by an unsteady computational fluid dynamics calculation. A simulation with 13 million grid points has been completed, and comparisons are made between calculations with different turbulence models. Results indicate that the turbulence model has a profound effect on the levels and character of the unsteadiness. Flow data on solid surfaces and a set of permeable surfaces surrounding the gear have been collected. Noise predictions using the porous surfaces appear to be contaminated by errors caused by large wake fluctuations passing through the surfaces. However, comparisons between predictions using the solid surfaces with the near-field CFD solution are in good agreement giving confidence in the far-field results.
NASA Astrophysics Data System (ADS)
McCombs, A. G.; Hiscox, A.; Wang, C.; Desai, A. R.
2016-12-01
A challenge in satellite land surface remote-sensing models of ecosystem carbon dynamics in agricultural systems is the lack of differentiation by crop type and management. This generalization can lead to large discrepancies between model predictions and eddy covariance flux tower observations of net ecosystem exchange of CO2 (NEE). Literature confirms that NEE varies remarkably among different crop types making the generalization of agriculture in remote sensing based models inaccurate. Here, we address this inaccuracy by identifying and mapping net ecosystem exchange (NEE) in agricultural fields by comparing bulk modeling and modeling by crop type, and using this information to develop empirical models for future use. We focus on mapping NEE in maize and soybean fields in the US Great Plains at higher spatial resolution using the fusion of MODIS and LandSAT surface reflectance. MODIS observed reflectance was downscaled using the ESTARFM downscaling methodology to match spatial scales to those found in LandSAT and that are more appropriate for carbon dynamics in agriculture fields. A multiple regression model was developed from surface reflectance of the downscaled MODIS and LandSAT remote sensing values calibrated against five FLUXNET/AMERIFLUX flux towers located on soybean and/or maize agricultural fields in the US Great Plains with multi-year NEE observations. Our new methodology improves upon bulk approximates to map and model carbon dynamics in maize and soybean fields, which have significantly different photosynthetic capacities.
2014-11-03
CAPE CANAVERAL, Fla. - Rob Mueller, NASA senior technologist in the Surface Systems Office in Kennedy Space Center's Engineering and Technology Directorate, demonstrates the Regolith Advanced Surface System Operations Robot, or RASSOR, during a media event at Kennedy's automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility. The event was held to announce Moon Express Inc., of Moffett Field, California is selected to utilize Kennedy facilities for NASA's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST. Photo credit: NASA/Ben Smegelsky
2014-11-03
Rob Mueller, left, NASA senior technologist in the Surface Systems Office in Kennedy Space Center's Engineering and Technology Directorate, talks with former NASA Apollo astronaut Buzz Aldrin during a demonstration of the Regolith Advanced Surface Systems Operations Robot, or RASSOR, at the automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The event was held to announce Moon Express Inc., of Moffett Field, California is selected to utilize Kennedy facilities for NASA's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST.
2014-11-03
Rob Mueller, left, NASA senior technologist in the Surface Systems Office in Kennedy Space Center's Engineering and Technology Directorate, talks with former NASA Apollo astronaut Buzz Aldrin during a demonstration of the Regolith Advanced Surface System Operations Robot, or RASSOR, at the automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The event was held to announce Moon Express Inc., of Moffett Field, California is selected to utilize Kennedy facilities for NASA's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST.
NASA Astrophysics Data System (ADS)
Toohey, R.; Boll, J.; Brooks, E.; Jones, J.
2009-12-01
Surface runoff and percolation to ground water are two hydrological processes of concern to the Atlantic slope of Costa Rica because of their impacts on flooding and drinking water contamination. As per legislation, the Costa Rican Government funds land use management from the farm to the regional scale to improve or conserve hydrological ecosystem services. In this study, we examined how land use (e.g., forest, coffee, sugar cane, and pasture) affects hydrological response at the point, plot (1 m2), and the field scale (1-6ha) to empirically conceptualize the dominant hydrological processes in each land use. Using our field data, we upscaled these conceptual processes into a physically-based distributed hydrological model at the field, watershed (130 km2), and regional (1500 km2) scales. At the point and plot scales, the presence of macropores and large roots promoted greater vertical percolation and subsurface connectivity in the forest and coffee field sites. The lack of macropores and large roots, plus the addition of management artifacts (e.g., surface compaction and a plough layer), altered the dominant hydrological processes by increasing lateral flow and surface runoff in the pasture and sugar cane field sites. Macropores and topography were major influences on runoff generation at the field scale. Also at the field scale, antecedent moisture conditions suggest a threshold behavior as a temporal control on surface runoff generation. However, in this tropical climate with very intense rainstorms, annual surface runoff was less than 10% of annual precipitation at the field scale. Significant differences in soil and hydrological characteristics observed at the point and plot scales appear to have less significance when upscaled to the field scale. At the point and plot scales, percolation acted as the dominant hydrological process in this tropical environment. However, at the field scale for sugar cane and pasture sites, saturation-excess runoff increased as irrigation intensity and duration (e.g., quantity) increased. Upscaling our conceptual models to the watershed and regional scales, historical data (1970-2004) was used to investigate whether dominant hydrological processes changed over time due to land use change. Preliminary investigations reveal much higher runoff coefficients (<30%) at the larger watershed scales. The increase in importance of runoff at the larger geographic scales suggests an emerging process and process non-linearity between the smaller and larger scales. Upscaling is an important and useful concept when investigating catchment response using the tools of field work and/or physically distributed hydrological modeling.
NASA Astrophysics Data System (ADS)
Gayler, Sebastian; Wöhling, Thomas; Ingwersen, Joachim; Wizemann, Hans-Dieter; Warrach-Sagi, Kirsten; Attinger, Sabine; Streck, Thilo; Wulmeyer, Volker
2014-05-01
Interactions between the soil, the vegetation, and the atmospheric boundary layer require close attention when predicting water fluxes in the hydrogeosystem, agricultural systems, weather and climate. However, land-surface schemes used in large scale models continue to show deficits in consistently simulating fluxes of water and energy from the subsurface through vegetation layers to the atmosphere. In this study, the multi-physics version of the Noah land-surface model (Noah-MP) was used to identify the processes, which are most crucial for a simultaneous simulation of water and heat fluxes between land-surface and the lower atmosphere. Comprehensive field data sets of latent and sensible heat fluxes, ground heat flux, soil moisture, and leaf area index from two contrasting field sites in South-West Germany are used to assess the accuracy of simulations. It is shown that an adequate representation of vegetation-related processes is the most important control for a consistent simulation of energy and water fluxes in the soil-plant-atmosphere system. In particular, using a newly implemented sub-module to simulate root growth dynamics has enhanced the performance of Noah-MP at both field sites. We conclude that further advances in the representation of leaf area dynamics and root/soil moisture interactions are the most promising starting points for improving the simulation of feedbacks between the sub-soil, land-surface and atmosphere in fully-coupled hydrological and atmospheric models.
West Virginia wood waste from uncharted sources: log landings and active surface mines
Shawn T. Grushecky; Lawrence E. Osborn
2013-01-01
Traditionally, biomass availability estimates from West Virginia have focused on primary and secondary mill byproducts and logging residues. Other sources of woody biomass are available that have not been surveyed. Through a series of field studies during 2010 and 2011, biomass availability estimates were developed for surface mine sites and log landings in West...
Search for the Mars 2 Debris Field
2014-10-29
NASA Mars Reconnaissance Orbiter acquired this image to aid in the search for the missing lander, Mars 2. If the debris field is found, it could serve as a future landing location to study the effects of crash landing on the Martian surface. Despite the recent successes of missions landing on Mars, like the Mars Science Laboratory (Curiosity) or the arrival of new satellites, such as India's MOM orbiter, the Red Planet is also a graveyard of failed missions. The Soviet Mars 2 lander was the first man-made object to touch the surface of the Red Planet when it crashed landed on 27 November 1971. It is believed that the descent stage malfunctioned after the lander entered the atmosphere at too steep an angle. Attempts to contact the probe after the crash were unsuccessful. http://photojournal.jpl.nasa.gov/catalog/PIA18888
NASA Technical Reports Server (NTRS)
Santanello, Joseph
2011-01-01
NASA's Land Information System (LIS; lis.gsfc.nasa.gov) is a flexible land surface modeling and data assimilation framework developed over the past decade with the goal of integrating satellite- and ground-based observational data products and advanced land surface modeling techniques to produce optimal fields of land surface states and fluxes. LIS features a high performance and flexible design, and operates on an ensemble of land surface models for extension over user-specified regional or global domains. The extensible interfaces of LIS allow the incorporation of new domains, land surface models (LSMs), land surface parameters, meteorological inputs, data assimilation and optimization algorithms. In addition, LIS has also been demonstrated for parameter estimation and uncertainty estimation, and has been coupled to the Weather Research and Forecasting (WRF) mesoscale model. A visiting fellowship is currently underway to implement JULES into LIS and to undertake some fundamental science on the feedbacks between the land surface and the atmosphere. An overview of the LIS system, features, and sample results will be presented in an effort to engage the community in the potential advantages of LIS-JULES for a range of applications. Ongoing efforts to develop a framework for diagnosing land-atmosphere coupling will also be presented using the suite of LSM and PBL schemes available in LIS and WRF along with observations from the U. S .. Southern Great Plains. This methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which will serve as a testbed for future experiments to evaluate coupling diagnostics within the community.
Slope effects on shortwave radiation components and net radiation
NASA Technical Reports Server (NTRS)
Walter-Shea, Elizabeth A.; Blad, Blaine L.; Hays, Cynthia J.; Mesarch, Mark A.
1992-01-01
The main objective of the International Satellite Land Surface Climatology Project (ISLSCP) has been stated as 'the development of techniques that may be applied to satellite observations of the radiation reflected and emitted from the Earth to yield quantitative information concerning land surface climatological conditions.' The major field study, FIFE (the First ISLSCP Field Experiment), was conducted in 1978-89 to accomplish this objective. Four intensive field campaigns (IFC's) were carried out in 1987 and one in 1989. Factors contributing to observed reflected radiation from the FIFE site must be understood before the radiation observed by satellites can be used to quantify surface processes. Analysis since our last report has focused on slope effects on incoming and outgoing shortwave radiation and net radiation from data collected in 1989.
The first ISLSCP field experiment (FIFE). [International Satellite Land Surface Climatology Project
NASA Technical Reports Server (NTRS)
Sellers, P. J.; Hall, F. G.; Asrar, G.; Strebel, D. E.; Murphy, R. E.
1988-01-01
The background and planning of the first International Satellite Land Surface Climatology Project (ISLSCP) field experiment (FIFE) are discussed. In FIFE, the NOAA series of satellites and GOES will be used to provide a moderate-temporal resolution coarse-spatial resolution data set, with SPOT and aircraft data providing the high-spatial resolution pointable-instrument capability. The paper describes the experiment design, the measurement strategy, the configuration of the site of the experiment (which will be at and around the Konza prairie near Manhattan, Kansas), and the experiment's operations and execution.
NASA Astrophysics Data System (ADS)
Liu, Q.; Li, J.; Du, Y.; Wen, J.; Zhong, B.; Wang, K.
2011-12-01
As the remote sensing data accumulating, it is a challenge and significant issue how to generate high accurate and consistent land surface parameter product from the multi source remote observation and the radiation transfer modeling and inversion methodology are the theoretical bases. In this paper, recent research advances and unresolved issues are presented. At first, after a general overview, recent research advances on multi-scale remote sensing radiation transfer modeling are presented, including leaf spectrum model, vegetation canopy BRDF models, directional thermal infrared emission models, rugged mountains area radiation models, and kernel driven models etc. Then, new methodologies on land surface parameters inversion based on multi-source remote sensing data are proposed, taking the land surface Albedo, leaf area index, temperature/emissivity, and surface net radiation as examples. A new synthetic land surface parameter quantitative remote sensing product generation system is suggested and the software system prototype will be demonstrated. At last, multi-scale field experiment campaigns, such as the field campaigns in Gansu and Beijing, China are introduced briefly. The ground based, tower based, and airborne multi-angular measurement system have been built to measure the directional reflectance, emission and scattering characteristics from visible, near infrared, thermal infrared and microwave bands for model validation and calibration. The remote sensing pixel scale "true value" measurement strategy have been designed to gain the ground "true value" of LST, ALBEDO, LAI, soil moisture and ET etc. at 1-km2 for remote sensing product validation.
Land-atmosphere interactions over the continental United States
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zeng, Xubin
This paper briefly discusses four suggested modifications for land surface modeling in climate models. The impact of the modifications on climate simulations is analyzed with the Biosphere-Atmosphere Transfer Scheme (BATS) land surface model. It is found that the modifications can improve BATS simulations. In particular, the sensitivity of BATS to the prescribed value of physical root fraction which cannot be observed from satellite remote sensing or field experiments is improved. These modifications significantly reduce the excessive summer land surface temperature over the continental United States simulated by the National Center for Atmospheric Research Community Climate Model (CCM2) coupled with BATS.more » A land-atmosphere interaction mechanism involving energy and water cycles is proposed to explain the results. 9 refs., 1 fig.« less
NASA Technical Reports Server (NTRS)
Wang, Yansen; Tao, W.-K.; Lau, K.-M.; Wetzel, Peter J.
2003-01-01
The onset of the southeast Asian monsoon during 1997 and 1998 was simulated with a coupled mesoscale atmospheric model (MM5) and a detailed land surface model. The rainfall results from the simulations were compared with observed satellite data fiom the TRMM (Tropical Rainfall Measuring Mission) TMI (TRMM Microwave Imager) and GPCP (Global Precipitation Climatology Project). The simulation with the land surface model captured basic signatures of the monsoon onset processes and associated rainfall statistics. The sensitivity tests indicated that land surface processes had a greater impact on the simulated rainfall results than that of a small sea surface temperature change during the onset period. In both the 1997 and 1998 cases, the simulations were significantly improved by including the land surface processes. The results indicated that land surface processes played an important role in modifying the low-level wind field over two major branches of the circulation; the southwest low-level flow over the Indo- China peninsula and the northern cold front intrusion from southern China. The surface sensible and latent heat exchange between the land and atmosphere modified the lowlevel temperature distribution and gradient, and therefore the low-level. The more realistic forcing of the sensible and latent heat from the detailed land surface model improved the monsoon rainfall and associated wind simulation.
USDA-ARS?s Scientific Manuscript database
Accurate estimation of surface energy fluxes at field scale over large areas has the potential to improve agricultural water management in arid and semiarid watersheds. Remote sensing may be the only viable approach for mapping fluxes over heterogeneous landscapes. The Two-Source Energy Balance mode...
Diurnal Cycle of Surface Flows During NAME and Comparison to Model Reanalysis
NASA Astrophysics Data System (ADS)
Ciesielski, P. E.; Johnson, R. H.
2007-05-01
During the North American Monsoon Experiment (NAME) an unprecedented surface data set of winds and thermodynamic variables was collected over the core monsoon region. The surface network included 63 automated sites with 1-30 min resolution data, 27 SMN operational sites (1-3 hourly data), and 56 US operational sites (1-3 hourly data) along the northern fringe of the monsoon region. These data, along with twice daily QuikSCAT oceanic surface winds, were quality controlled and objectively analyzed on to a uniform grid with quarter-degree, 1-h resolution for the period from 1 July - 15 August. An important application of the gridded winds is their use in diagnosing surface vertical motion due to slope flows over the Sierra Madre Occidental (SMO) terrain. With this dataset we examine the diurnal characteristics of surface fields as the monsoon evolves and compare these analyses to similar surface products from the special North American Regional Reanalysis (NARR) for NAME. Observed surface fields indicate that a robust land-sea breeze circulation is present over most of Gulf of California (GOC) region in response to the strong diurnal heating of land masses on both sides of the gulf. For reasons unclear at this time, many features of this land-sea breeze circulation are missing in the NARR. Evolution of the diurnal cycle of temperature and the land- sea breeze circulation as the monsoon progresses through the season shows a strong sensitivity to rainfall over the SMO and the coastal plains. Such a relationship likely reflects changes in land surface characteristics, such as evapotranspiration and albedo, as the forests of the SMO respond to monsoonal rains.
NASA Astrophysics Data System (ADS)
Gayler, Sebastian; Wöhling, Thomas; Högy, Petra; Ingwersen, Joachim; Wizemann, Hans-Dieter; Wulfmeyer, Volker; Streck, Thilo
2013-04-01
During the last years, land-surface models have proven to perform well in several studies that compared simulated fluxes of water and energy from the land surface to the atmosphere against measured fluxes at the plot-scale. In contrast, considerable deficits of land-surface models have been identified to simulate soil water fluxes and vertical soil moisture distribution. For example, Gayler et al. (2013) showed that simplifications in the representation of root water uptake can result in insufficient simulations of the vertical distribution of soil moisture and its dynamics. However, in coupled simulations of the terrestrial water cycle, both sub-systems, the atmosphere and the subsurface hydrogeo-system, must fit together and models are needed, which are able to adequately simulate soil moisture, latent heat flux, and their interrelationship. Consequently, land-surface models must be further improved, e.g. by incorporation of advanced biogeophysics models. To improve the conceptual realism in biophysical and hydrological processes in the community land surface model Noah, this model was recently enhanced to Noah-MP by a multi-options framework to parameterize individual processes (Niu et al., 2011). Thus, in Noah-MP the user can choose from several alternative models for vegetation and hydrology processes that can be applied in different combinations. In this study, we evaluate the performance of different Noah-MP model settings to simulate water and energy fluxes across the land surface at two contrasting field sites in South-West Germany. The evaluation is done in 1D offline-mode, i.e. without coupling to an atmospheric model. The atmospheric forcing is provided by measured time series of the relevant variables. Simulation results are compared with eddy covariance measurements of turbulent fluxes and measured time series of soil moisture at different depths. The aims of the study are i) to carve out the most appropriate combination of process parameterizations in Noah-MP to simultaneously match the different components of the water and energy cycle at the field sites under consideration, and ii) to estimate the uncertainty in model structure. We further investigate the potential to improve simulation results by incorporating concepts of more advanced root water uptake models from agricultural field scale models into the land-surface-scheme. Gayler S, Ingwersen J, Priesack E, Wöhling T, Wulfmeyer V, Streck T (2013): Assessing the relevance of sub surface processes for the simulation of evapotranspiration and soil moisture dynamics with CLM3.5: Comparison with field data and crop model simulations. Environ. Earth Sci., 69(2), under revision. Niu G-Y, Yang Z-L, Mitchell KE, Chen F, Ek MB, Barlage M, Kumar A, Manning K, Niyogi D, Rosero E, Tewari M and Xia Y (2011): The community Noah land surface model with multiparameterization options (Noah-MP): 1. Model description and evaluation with local-scale measurements. Journal of Geophysical Research 116(D12109).
Effects of land use on surface-water quality in the East Everglades, Dade County, Florida
Waller, Bradley G.
1982-01-01
Water-quality characteristics were determined at five developed areas in the East Everglades, Dade County, Florida, during the 1978 wet season (June through October). These areas are designated as: Coopertown; Chekika Hammock State Park; residential area; rock-plowed tomato field; and Cracker Jack Slough agricultural area. Data from the developed areas were compared with data from four baseline sites in undeveloped areas to determine the effects of land use on the surface-water quality. The rock-plowed tomato field was the only area where surface-water quality was affected. Water quality at this field is affected by agricultural activities and chemical applications as indicated by increased concentrations of orthophosphate, organic nitrogen, organic carbon, copper, manganese, mercury, and potassium. The remaining four areas of land use had water-quality characteristics typical of baseline sites in nearby Northeast Shark River Slough or Taylor Slough. Chemical analyses of soil indicated chlorinated-hydrocarbon insecticide residues at Coopertown and the two agricultural areas, Cracker Jack Slough and the rock-plowed tomato field. Trace elements in concentrations greater than base level occurred at both agricultural areas (manganese), Chekika Hammock State Park (manganese), and at Coopertown (lead and zinc). (USGS)
NASA Technical Reports Server (NTRS)
Houser, Paul (Technical Monitor); Patton, Edward G.; Sullivan, Peter P.; Moeng, Chin-Hoh
2003-01-01
This is the first in a two-part series of manuscripts describing numerical experiments on the influence of 2-30 km striplike heterogeneity on wet and dry boundary layers coupled to the land surface. The strip-like heterogeneity is shown to dramatically alter the structure of the free-convective boundary layer by inducing significant organized circulations that modify turbulent statistics. The coupling with the land-surface modifies the circulations compared to previous studies using fixed surface forcing. Total boundary layer turbulence kinetic energy increases significantly for surface heterogeneity at scales between Lambda/z(sub i) = 4 and 9, however entrainment rates for all cases are largely unaffected by the strip-like heterogeneity.
Surface-material maps of Viking landing sites on Mars
NASA Technical Reports Server (NTRS)
Moore, H. J.; Keller, J. M.
1991-01-01
Researchers mapped the surface materials at the Viking landing sites on Mars to gain a better understanding of the materials and rock populations at the sites and to provide information for future exploration. The maps extent to about 9 m in front of each lander and are about 15 m wide - an area comparable to the area of a pixel in high resolution Viking Orbiter images. The maps are divided into the near and far fields. Data for the near fields are from 1/10 scale maps, umpublished maps, and lander images. Data for the far fields are from 1/20 scale contour maps, contoured lander camera mosaics, and lander images. Rocks are located on these maps using stereometric measurements and the contour maps. Frequency size distribution of rocks and the responses of soil-like materials to erosion by engine exhausts during landings are discussed.
Inclusion of Solar Elevation Angle in Land Surface Albedo Parameterization Over Bare Soil Surface.
Zheng, Zhiyuan; Wei, Zhigang; Wen, Zhiping; Dong, Wenjie; Li, Zhenchao; Wen, Xiaohang; Zhu, Xian; Ji, Dong; Chen, Chen; Yan, Dongdong
2017-12-01
Land surface albedo is a significant parameter for maintaining a balance in surface energy. It is also an important parameter of bare soil surface albedo for developing land surface process models that accurately reflect diurnal variation characteristics and the mechanism behind the solar spectral radiation albedo on bare soil surfaces and for understanding the relationships between climate factors and spectral radiation albedo. Using a data set of field observations, we conducted experiments to analyze the variation characteristics of land surface solar spectral radiation and the corresponding albedo over a typical Gobi bare soil underlying surface and to investigate the relationships between the land surface solar spectral radiation albedo, solar elevation angle, and soil moisture. Based on both solar elevation angle and soil moisture measurements simultaneously, we propose a new two-factor parameterization scheme for spectral radiation albedo over bare soil underlying surfaces. The results of numerical simulation experiments show that the new parameterization scheme can more accurately depict the diurnal variation characteristics of bare soil surface albedo than the previous schemes. Solar elevation angle is one of the most important factors for parameterizing bare soil surface albedo and must be considered in the parameterization scheme, especially in arid and semiarid areas with low soil moisture content. This study reveals the characteristics and mechanism of the diurnal variation of bare soil surface solar spectral radiation albedo and is helpful in developing land surface process models, weather models, and climate models.
NASA Astrophysics Data System (ADS)
Liu, Q.
2011-09-01
At first, research advances on radiation transfer modeling on multi-scale remote sensing data are presented: after a general overview of remote sensing radiation transfer modeling, several recent research advances are presented, including leaf spectrum model (dPROS-PECT), vegetation canopy BRDF models, directional thermal infrared emission models(TRGM, SLEC), rugged mountains area radiation models, and kernel driven models etc. Then, new methodologies on land surface parameters inversion based on multi-source remote sensing data are proposed. The land surface Albedo, leaf area index, temperature/emissivity, and surface net radiation etc. are taken as examples. A new synthetic land surface parameter quantitative remote sensing product generation system is designed and the software system prototype will be demonstrated. At last, multi-scale field experiment campaigns, such as the field campaigns in Gansu and Beijing, China will be introduced briefly. The ground based, tower based, and airborne multi-angular measurement system have been built to measure the directional reflectance, emission and scattering characteristics from visible, near infrared, thermal infrared and microwave bands for model validation and calibration. The remote sensing pixel scale "true value" measurement strategy have been designed to gain the ground "true value" of LST, ALBEDO, LAI, soil moisture and ET etc. at 1-km2 for remote sensing product validation.
NASA Technical Reports Server (NTRS)
Tao, W.-K.; Lau, W.; Baker, R.
2004-01-01
The onset of the southeast Asian monsoon during 1997 and 1998 was simulated with a coupled mesoscale atmospheric model (MM5) and a detailed land surface model. The rainfall results from the simulations were compared with observed satellite data from the TRMM (Tropical Rainfall Measuring Mission) TMI (TRMM Microwave Imager) and GPCP (Global Precipitation Climatology Project). The simulation with the land surface model captured basic signatures of the monsoon onset processes and associated rainfall statistics. The sensitivity tests indicated that land surface processes had a greater impact on the simulated rainfall results than that of a small sea surface temperature change during the onset period. In both the 1997 and 1998 cases, the simulations were significantly improved by including the land surface processes. The results indicated that land surface processes played an important role in modifying the low-level wind field over two major branches of the circulation; the southwest low-level flow over the Indo-China peninsula and the northern cold front intrusion from southern China. The surface sensible and latent heat exchange between the land and atmosphere modified the low-level temperature distribution and gradient, and therefore the low-level. The more realistic forcing of the sensible and latent heat from the detailed land surface model improved the monsoon rainfall and associated wind simulation. The model results will be compared to the simulation of the 6-7 May 2000 Missouri flash flood event. In addition, the impact of model initialization and land surface treatment on timing, intensity, and location of extreme precipitation will be examined.
NASA Technical Reports Server (NTRS)
Tao, W.-K.; Wang, Y.; Lau, W.; Baker, R. D.
2004-01-01
The onset of the southeast Asian monsoon during 1997 and 1998 was simulated with a coupled mesoscale atmospheric model (MM5) and a detailed land surface model. The rainfall results from the simulations were compared with observed satellite data from the TRMM (Tropical Rainfall Measuring Mission) TMI (TRMM Microwave Imager) and GPCP (Global Precipitation Climatology Project). The simulation with the land surface model captured basic signatures of the monsoon onset processes and associated rainfall statistics. The sensitivity tests indicated that land surface processes had a greater impact on the simulated rainfall results than that of a small sea surface temperature change during the onset period. In both the 1997 and 1998 cases, the simulations were significantly improved by including the land surface processes. The results indicated that land surface processes played an important role in modifying the low-level wind field over two major branches of the circulation; the southwest low-level flow over the Indo-China peninsula and the northern cold front intrusion from southern China. The surface sensible and latent heat exchange between the land and atmosphere modified the low-level temperature distribution and gradient, and therefore the low-level. The more realistic forcing of the sensible and latent heat from the detailed land surface model improved the monsoon rainfall and associated wind simulation. The model results will be compared to the simulation of the 6-7 May 2000 Missouri flash flood event. In addition, the impact of model initialization and land surface treatment on timing, intensity, and location of extreme precipitation will be examined.
NASA Astrophysics Data System (ADS)
Salvucci, G.; Rigden, A. J.; Gentine, P.; Lintner, B. R.
2013-12-01
A new method was recently proposed for estimating evapotranspiration (ET) from weather station data without requiring measurements of surface limiting factors (e.g. soil moisture, leaf area, canopy conductance) [Salvucci and Gentine, 2013, PNAS, 110(16): 6287-6291]. Required measurements include diurnal air temperature, specific humidity, wind speed, net shortwave radiation, and either measured or estimated incoming longwave radiation and ground heat flux. The approach is built around the idea that the key, rate-limiting, parameter of typical ET models, the land-surface resistance to water vapor transport, can be estimated from an emergent relationship between the diurnal cycle of the relative humidity profile and ET. The emergent relation is that the vertical variance of the relative humidity profile is less than what would occur for increased or decreased evaporation rates, suggesting that land-atmosphere feedback processes minimize this variance. This relation was found to hold over a wide range of climate conditions (arid to humid) and limiting factors (soil moisture, leaf area, energy) at a set of Ameriflux field sites. While the field tests in Salvucci and Gentine (2013) supported the minimum variance hypothesis, the analysis did not reveal the mechanisms responsible for the behavior. Instead the paper suggested, heuristically, that the results were due to an equilibration of the relative humidity between the land surface and the surface layer of the boundary layer. Here we apply this method using surface meteorological fields simulated by a global climate model (GCM), and compare the predicted ET to that simulated by the climate model. Similar to the field tests, the GCM simulated ET is in agreement with that predicted by minimizing the profile relative humidity variance. A reasonable interpretation of these results is that the feedbacks responsible for the minimization of the profile relative humidity variance in nature are represented in the climate model. The climate model components, in particular the land surface model and boundary layer representation, can thus be analyzed in controlled numerical experiments to discern the specific processes leading to the observed behavior. Results of this analysis will be presented.
Land Surface Data Assimilation
NASA Astrophysics Data System (ADS)
Houser, P. R.
2012-12-01
Information about land surface water, energy and carbon conditions is of critical importance to real-world applications such as agricultural production, water resource management, flood prediction, water supply, weather and climate forecasting, and environmental preservation. While ground-based observational networks are improving, the only practical way to observe these land surface states on continental to global scales is via satellites. Remote sensing can make spatially comprehensive measurements of various components of the terrestrial system, but it cannot provide information on the entire system (e.g. evaporation), and the observations represent only an instant in time. Land surface process models may be used to predict temporal and spatial terrestrial dynamics, but these predictions are often poor, due to model initialization, parameter and forcing, and physics errors. Therefore, an attractive prospect is to combine the strengths of land surface models and observations (and minimize the weaknesses) to provide a superior terrestrial state estimate. This is the goal of land surface data assimilation. Data Assimilation combines observations into a dynamical model, using the model's equations to provide time continuity and coupling between the estimated fields. Land surface data assimilation aims to utilize both our land surface process knowledge, as embodied in a land surface model, and information that can be gained from observations. Both model predictions and observations are imperfect and we wish to use both synergistically to obtain a more accurate result. Moreover, both contain different kinds of information, that when used together, provide an accuracy level that cannot be obtained individually. Model biases can be mitigated using a complementary calibration and parameterization process. Limited point measurements are often used to calibrate the model(s) and validate the assimilation results. This presentation will provide a brief background on land surface observation, modeling and data assimilation, followed by a discussion of various hydrologic data assimilation challenges, and finally conclude with several land surface data assimilation case studies.
2014-11-03
CAPE CANAVERAL, Fla. - Rob Mueller, left, NASA senior technologist in the Surface Systems Office in Kennedy Space Center's Engineering and Technology Directorate, talks with former NASA Apollo astronaut Buzz Aldrin during a demonstration of the Regolith Advanced Surface System Operations Robot, or RASSOR, at the automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The event was held to announce Moon Express Inc., of Moffett Field, California is selected to utilize Kennedy facilities for NASA's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST. Photo credit: NASA/Ben Smegelsky
2014-11-03
CAPE CANAVERAL, Fla. - Rob Mueller, left, NASA senior technologist in the Surface Systems Office in Kennedy Space Center's Engineering and Technology Directorate, talks with former NASA Apollo astronaut Buzz Aldrin during a demonstration of the Regolith Advanced Surface Systems Operations Robot, or RASSOR, at the automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The event was held to announce Moon Express Inc., of Moffett Field, California is selected to utilize Kennedy facilities for NASA's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST. Photo credit: NASA/Ben Smegelsky
Estimating surface fluxes over middle and upper streams of the Heihe River Basin with ASTER imagery
NASA Astrophysics Data System (ADS)
Ma, W.; Ma, Y.; Hu, Z.; Su, Z.; Wang, J.; Ishikawa, H.
2011-05-01
Land surface heat fluxes are essential measures of the strengths of land-atmosphere interactions involving energy, heat and water. Correct parameterization of these fluxes in climate models is critical. Despite their importance, state-of-the-art observation techniques cannot provide representative areal averages of these fluxes comparable to the model grid. Alternative methods of estimation are thus required. These alternative approaches use (satellite) observables of the land surface conditions. In this study, the Surface Energy Balance System (SEBS) algorithm was evaluated in a cold and arid environment, using land surface parameters derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data. Field observations and estimates from SEBS were compared in terms of net radiation flux (Rn), soil heat flux (G0), sensible heat flux (H) and latent heat flux (λE) over a heterogeneous land surface. As a case study, this methodology was applied to the experimental area of the Watershed Allied Telemetry Experimental Research (WATER) project, located on the mid-to-upstream sections of the Heihe River in northwest China. ASTER data acquired between 3 May and 4 June 2008, under clear-sky conditions were used to determine the surface fluxes. Ground-based measurements of land surface heat fluxes were compared with values derived from the ASTER data. The results show that the derived surface variables and the land surface heat fluxes furnished by SEBS in different months over the study area are in good agreement with the observed land surface status under the limited cases (some cases looks poor results). So SEBS can be used to estimate turbulent heat fluxes with acceptable accuracy in areas where there is partial vegetation cover in exceptive conditions. It is very important to perform calculations using ground-based observational data for parameterization in SEBS in the future. Nevertheless, the remote-sensing results can provide improved explanations of land surface fluxes over varying land coverage at greater spatial scales.
NASA Technical Reports Server (NTRS)
Wang, Yansen; Tao, W.-K.; Lau, K.-M.; Wetzel, Peter J.
2004-01-01
The onset of the southeast Asian monsoon during 1997 and 1998 was simulated by coupling a mesoscale atmospheric model (MM5) and a detailed, land surface model, PLACE (the Parameterization for Land-Atmosphere-Cloud Exchange). The rainfall results from the simulations were compared with observed satellite data from the TRMM (Tropical Rainfall Measuring Mission) TMI (TRMM Microwave Imager) and GPCP (Global Precipitation Climatology Project). The control simulation with the PLACE land surface model and variable sea surface temperature captured the basic signatures of the monsoon onset processes and associated rainfall statistics. Sensitivity tests indicated that simulations were sigmficantly improved by including the PLACE land surface model. The mechanism by which the land surface processes affect the moisture transport and the convection during the onset of the southeast Asian monsoon were analyzed. The results indicated that land surface processes played an important role in modifying the low-level wind field over two major branches of the circulation: the southwest low-level flow over the Indo-china peninsula and the northern, cold frontal intrusion from southern China. The surface sensible and latent heat fluxes modified the low-level temperature distribution and gradient, and therefore the low-level wind due to the thermal wind effect. The more realistic forcing of the sensible and latent heat fluxes from the detailed, land surface model improved the low-level wind simulation apd associated moisture transport and convection.
NASA Technical Reports Server (NTRS)
Wang, Yansen; Tao, W.-K.; Lau, K.-M.; Wetzel, Peter J.
2004-01-01
The onset of the southeast Asian monsoon during 1997 and 1998 was simulated by coupling a mesoscale atmospheric model (MM5) and a detailed, land surface model, PLACE (the Parameterization for Land-Atmosphere-Cloud Exchange). The rainfall results from the simulations were compared with observed satellite data from the TRMM (Tropical Rainfall Measuring Mission) TMI (TRMM Microwave Imager) and GPCP (Global Precipitation Climatology Project). The control simulation with the PLACE land surface model and variable sea surface temperature captured the basic signatures of the monsoon onset processes and associated rainfall statistics. Sensitivity tests indicated that simulations were significantly improved by including the PLACE land surface model. The mechanism by which the land surface processes affect the moisture transport and the convection during the onset of the southeast Asian monsoon were analyzed. The results indicated that land surface processes played an important role in modifying the low-level wind field over two major branches of the circulation: the southwest low-level flow over the Indo-China peninsula and the northern, cold frontal intrusion from southern China. The surface sensible and latent heat fluxes modified the low-level temperature distribution and merit, and therefore the low-level wind due to the thermal wind effect. The more realistic forcing of the sensible and latent heat fluxes from the detailed, land surface model improved the low-level wind simulation and associated moisture transport and convection.
Zobeck, T.M.; Parker, N.C.; Haskell, S.; Guoding, K.
2000-01-01
Factors that affect wind erosion such as surface vegetative and other cover, soil properties and surface roughness usually change spatially and temporally at the field-scale to produce important field-scale variations in wind erosion. Accurate estimation of wind erosion when scaling up from fields to regions, while maintaining meaningful field-scale process details, remains a challenge. The objectives of this study were to evaluate the feasibility of using a field-scale wind erosion model with a geographic information system (GIS) to scale up to regional levels and to quantify the differences in wind erosion estimates produced by different scales of soil mapping used as a data layer in the model. A GIS was used in combination with the revised wind erosion equation (RWEQ), a field-scale wind erosion model, to estimate wind erosion for two 50 km2 areas. Landsat Thematic Mapper satellite imagery from 1993 with 30 m resolution was used as a base map. The GIS database layers included land use, soils, and other features such as roads. The major land use was agricultural fields. Data on 1993 crop management for selected fields of each crop type were collected from local government agency offices and used to 'train' the computer to classify land areas by crop and type of irrigation (agroecosystem) using commercially available software. The land area of the agricultural land uses was overestimated by 6.5% in one region (Lubbock County, TX, USA) and underestimated by about 21% in an adjacent region (Terry County, TX, USA). The total estimated wind erosion potential for Terry County was about four times that estimated for adjacent Lubbock County. The difference in potential erosion among the counties was attributed to regional differences in surface soil texture. In a comparison of different soil map scales in Terry County, the generalised soil map had over 20% more of the land area and over 15% greater erosion potential in loamy sand soils than did the detailed soil map. As a result, the wind erosion potential determined using the generalised soil map Was about 26% greater than the erosion potential estimated by using the detailed soil map in Terry County. This study demonstrates the feasibility of scaling up from fields to regions to estimate wind erosion potential by coupling a field-scale wind erosion model with GIS and identifies possible sources of error with this approach.
Harned, Douglas A.
1995-01-01
The effects of selected agricultural land-management practices on water quality were assessed in a comparative study of four small basins in the Piedmont province of North Carolina. Agricultural practices, such as tillage and applications of fertilizer and pesticides, are major sources of sediment, nutrients, and pesticides in surface water, and of nutrients and pesticides in ground water. The four study basins included two adjacent row-crop fields, a mixed land-use basin, and a forested basin. One of the row-crop fields (7.4 acres) was farmed by using conservation land-management (CLM) practices, which included strip cropping, contour plowing, field borders, and grassed waterways. The other row-crop field (4.8 acres) was farmed by using standard land-management (SLM) practices, which included continuous cropping, straight-row plowing without regard to land topography, and poorly maintained waterways. The mixed land-use basin (665 acres) was monitored to compare water quality in surface water as SLM practices were converted to CLM practices during the project. The forested basin (44 acres) provided background surface-water hydrologic and chemical-quality conditions. Surface-water flow was reduced by 18 percent by CLM practices compared to surface-water flow from the SLM practices basin. The thickness of the unsaturated zone in the row-crop basins ranged from a few feet to 25 feet. Areas with thick unsaturated zones have a greater capacity to intercept and store nutrients and pesticides than do areas with thinner zones. Sediment concentrations and yields for the SLM practices basin were considerably higher than those for the other basins. The median sediment concentration in surface water for the SLM basin was 3.4 times that of the CLM basin, 8.2 times that of the mixed land-use basin, and 38.4 times that of the forested basin. The total sediment yield for the SLM basin was 2.3 times that observed for the CLM basin, 14.1 times that observed for the mixed land-use basin, and 19.5 times the yield observed for the forested basin. Nutrient concentrations in surface water from the row-crop and mixed land-use basins were higher than those measured in the forested basin and in precipitation collected near the row-crop basins. The SLM basin generally had the highest concentrations of total nitrogen, nitrite plus nitrate, total phosphorus (equivalent to the mixed land-use basin), and potassium. Nutrient concentrations in soil water and ground water were less than concentrations in surface water for the row-crop basins. Nutrient concentrations generally were at least slightly below the root zone (3-foot depth) and in ground water. Differences in nutrient yields among basins had patterns similar to those observed for nutrient concentrations. The total nitrogen yield for the SLM basin was 1.2 times the yield for the CLM basin, 1.9 times the yield for the mixed land-use basin, and 4.2 times the yield for the forested basin. The total phosphorus yield for the SLM basin was 1.7 times the yield for the CLM basin, 3.3 times the yield for the mixed land-use basin, and 7.8 times the yield for the forested basin. No significant differences in pesticide concentrations in surface water were identified between those measured in the SLM basin and those measured in the CLM basin. Significantly higher pesticide concentrations were observed at the row-crop basins compared with those observed at the mixed land-use basin probably because sampling sites for the row-crop basins were closer to the pesticide sources. No pesticides were detected in the forested basin. Comparisons of pesticide concentrations in soil from the two row-crop basins indicated some differences. Concentrations of the soil pesticides isopropalin and flumetralin were higher in the SLM basin than in the CLM basin. The surface-water quality of the mixed land-use basin generally was less affected by agricultural nonpoint sources than that of the smaller row-crop b
NASA Technical Reports Server (NTRS)
Golombek, M. P. (Editor); Edgett, K. S. (Editor); Rice, J. W. , Jr. (Editor)
1995-01-01
Mars Pathfinder will place a single lander on the surface of Mars on July 4, 1997, following a December 1996 launch. As a result of the very successful first Mars Pathfinder Landing Site Workshop, the project has selected the Ares Vallis outflow channel in Chryse Planitia as the landing site. This location is where a large catastrophic outflow channel debouches into the northern lowlands. A second workshop and series of field trips, entitled Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region and Field Trips in the Channeled Scabland, Washington, were held in Spokane and Moses Lake, Washington. The purpose of the workshop was to provide a focus for learning as much as possible about the Ares Vallis region on Mars before landing there. The rationale is that the more that can be learned about the general area prior to landing, the better scientists will be able interpret the observations made by the lander and rover and place them in the proper geologic context. The field trip included overflights and surface investigations of the Channeled Scabland (an Earth analog for the martian catastrophic outflow channels), focusing on areas particularly analogous to Ares Vallis and the landing site. The overflights were essential for placing the enormous erosional and depositional features of the Channeled Scabland into proper three-dimensional context. The field trips were a joint educational outreach activity involving K-12 science educators, Mars Pathfinder scientists and engineers, and interested scientists from the Mars scientific community. Part 1 of the technical report on this workshop includes a description of the Mars Pathfinder mission, abstracts accepted for presentation at the workshop, an introduction to the Channeled Scabland, and field trip guides for the overflight and two field trips. This part, Part 2, includes the program for the workshop, summaries of the workshop technical sessions, a summary of the field trips and ensuing discussions, late abstracts of workshop presentations, reports on the education and public outreach activities carried out by the educators, and a list of the workshop and field trip participants.
NASA Technical Reports Server (NTRS)
Halpern, D.
1984-01-01
The natural variability of the equatorial Pacific surface wind field is described from long period surface wind measurements made at three sites along the equator (95 deg W, 109 deg 30 W, 152 deg 30 W). The data were obtained from surface buoys moored in the deep ocean far from islands or land, and provide criteria to adequately sample the tropical Pacific winds from satellites.
MODIS Vegetative Cover Conversion and Vegetation Continuous Fields
NASA Astrophysics Data System (ADS)
Carroll, Mark; Townshend, John; Hansen, Matthew; DiMiceli, Charlene; Sohlberg, Robert; Wurster, Karl
Land cover change occurs at various spatial and temporal scales. For example, large-scale mechanical removal of forests for agro-industrial activities contrasts with the small-scale clearing of subsistence farmers. Such dynamics vary in spatial extent and rate of land conversion. Such changes are attributable to both natural and anthropogenic factors. For example, lightning- or human-ignited fires burn millions of acres of land surface each year. Further, land cover conversion requires contrasting with the land cover modification. In the first instance, the dynamic represents extensive categorical change between two land cover types. Land cover modification mechanisms such as selective logging and woody encroachment depict changes within a given land cover type rather than a conversion from one land cover type to another. This chapter describes the production of two standard MODIS land products used to document changes in global land cover. The Vegetative Cover Conversion (VCC) product is designed primarily to serve as a global alarm for areas where land cover change occurs rapidly (Zhan et al. 2000). The Vegetation Continuous Fields (VCF) product is designed to continuously represent ground cover as a proportion of basic vegetation traits. Terra's launch in December 1999 afforded a new opportunity to observe the entire Earth every 1.2 days at 250-m spatial resolution. The MODIS instrument's appropriate spatial and temporal resolutions provide the opportunity to substantially improve the characterization of the land surface and changes occurring thereupon (Townshend et al. 1991).
The Use of Solar Heating and Heat Cured Polymers for Lunar Surface Stabilization
NASA Technical Reports Server (NTRS)
Hintze, Paul; Curran, Jerry; Back, Reddy
2008-01-01
Dust ejecta can affect visibility during a lunar landing, erode nearby coated surfaces and get into mechanical assemblies of in-place infrastructure. Regolith erosion was observed at many of the Apollo landing sites. This problem needs to be addressed at the beginning of the lunar base missions, as the amount of infrastructure susceptible to problems will increase with each landing. Protecting infrastructure from dust and debris is a crucial step in its long term functionality. A proposed way to mitigate these hazards is to build a lunar launch pad. Other areas of a lunar habitat will also need surface stabilization methods to help mitigate dust hazards. Roads would prevent dust from being lifted during movement and dust free zones might be required for certain areas critical to crew safety or to critical science missions. Work at NASA Kennedy Space Center (KSC) is investigating methods of stabilizing the lunar regolith including: sintering the regolith into a solid and using heat or UV cured polymers to stabilize the surface. Sintering, a method in which powders are heated until fusing into solids, has been proposed as one way of building a Lunar launch/landing pad. A solar concentrator has been built and used in the field to sinter JSC-1 Lunar stimulant. Polymer palliatives are used by the military to build helicopter landing pads and roads in dusty and sandy areas. Those polymers are dispersed in a solvent (water), making them unsuitable for lunar use. Commercially available, solvent free, polymer powders are being investigated to determine their viability to work in the same way as the solvent borne terrestrial analog. This presentation will describe the ongoing work at KSC in this field. Results from field testing will be presented. Physical testing results, including compression and abrasion, of field and laboratory prepared samples will be presented.
NASA Technical Reports Server (NTRS)
Beaudoing, Hiroko Kato; Rodell, Matthew; Ozdogan, Mutlu
2010-01-01
Agricultural land use significantly influences the surface water and energy balances. Effects of irrigation on land surface states and fluxes include repartitioning of latent and sensible heat fluxes, an increase in net radiation, and an increase in soil moisture and runoff. We are working on representing irrigation practices in continental- to global-scale land surface simulation in NASA's Global Land Data Assimilation System (GLDAS). Because agricultural practices across the nations are diverse, and complex, we are attempting to capture the first-order reality of the regional practices before achieving a global implementation. This study focuses on two issues in Southeast Asia: multiple cropping and rice paddy irrigation systems. We first characterize agricultural practices in the region (i.e., crop types, growing seasons, and irrigation) using the Global data set of monthly irrigated and rainfed crop areas around the year 2000 (MIRCA2000) dataset. Rice paddy extent is identified using remote sensing products. Whether irrigated or rainfed, flooded fields need to be represented and treated explicitly. By incorporating these properties and processes into a physically based land surface model, we are able to quantify the impacts on the simulated states and fluxes.
New and Improved GLDAS Data Sets and Data Services at NASA GES DISC
NASA Technical Reports Server (NTRS)
Rui, Hualan; Beaudoing, Hiroko; Teng, William; Vollmer, Bruce; Rodell, Matthew; Lei, Guang-Dih
2012-01-01
The goal of a Land Data Assimilation System (LDAS) is to ingest satellite- and ground-based observational data products, using advanced land surface modeling and data assimilation techniques, in order to generate optimal fields of land surface states and fluxes data and, thereby, facilitate hydrology and climate modeling, research, and forecast. With the motivation of creating more climatologically consistent data sets, NASA GSFC's Hydrological Sciences Laboratory has generated more than 60 years (Jan. 1948-- Dec. 2008) of Global LDAS Version 2 (GLDAS-2) data, by using the Princeton Forcing Data Set and upgraded versions of Land Surface Models (LSMs). GLDAS data and data services are provided at NASA GES DISC Hydrology Data and Information Services Center (HDISC), in collaboration with HSL and LDAS.
NASA Astrophysics Data System (ADS)
Nicholson, S. E.
2013-12-01
The paper provides an historical review of research on the impact of the land surface on climate. It commences will the seminal work of Jule Charney on albedo as a potential cause of drought and follows the trail of follow-up studies on the question of desertification and its role in climate. With the exception of a very early paper by Namias, early work was limited mainly to modeling efforts. At the same time, several observational studies provided evidence that land surface feedbacks could enhance and prolong drought, especially in the African Sahel. Later work emphasized the role of soil moisture rather than albedo. Several important field studies also examined the role of the land surface. Examples include FIFE, HAPEX-Sahel and BOREAS. In recent years some major changes in the concept have occurred. There is now substantial observational evidence of an impact at the mesoscale. The role of land surface feedback on climate has become mainstream. Finally, a new subdiscipline has emerged that emphasizes feedbacks between the water cycle, vegetation and climate, namely ecohydrology.
NASA Astrophysics Data System (ADS)
Ueda, Shigenori; Iwasaki, Yoh; Ushioda, Sukekatsu
2003-10-01
The magnetic domain structures of Fe thin films on two-dimensionally arranged land-and-groove structures have been studied by spin-polarized secondary electron microscopy (SP-SEM) under an applied dc field. The coercive force on the land area was found to be higher than that on the groove area under magnetization reversal. The surface roughness measured by atomic force microscopy (AFM) was greater on the land area than on the groove area. The roughness-induced high-coercivity on the land prevented the reversed magnetic domain on the groove from spreading over the land in the initial magnetization reversal. This result indicates that surface roughness is an important factor in domain size control of thin magnetic films.
NASA Technical Reports Server (NTRS)
Wu, Steve Shih-Tseng
1997-01-01
Based on recent advances in microwave remote sensing of soil moisture and in pursuit of research interests in areas of hydrology, soil climatology, and remote sensing, the Center for Hydrology, Soil Climatology, and Remote Sensing (HSCARS) conducted the Huntsville '96 field experiment in Huntsville, Alabama from July 1-14, 1996. We, researchers at the Global Hydrology and Climate Center's MSFC/ES41, are interested in using ground-based microwave sensors, to simulate land surface brightness signatures of those spaceborne sensors that were in operation or to be launched in the near future. The analyses of data collected by the Advanced Microwave Precipitation Radiometer (AMPR) and the C-band radiometer, which together contained five frequencies (6.925,10.7,19.35, 37.1, and 85.5 GHz), and with concurrent in-situ collection of surface cover conditions (surface temperature, surface roughness, vegetation, and surface topology) and soil moisture content, would result in a better understanding of the data acquired over land surfaces by the Special Sensor Microwave Imager (SSM/I), the Tropical Rainfall Measuring Mission Microwave Imager (TMI), and the Advanced Microwave Scanning Radiometer (AMSR), because these spaceborne sensors contained these five frequencies. This paper described the approach taken and the specific objective to be accomplished in the Huntsville '97 field experiment.
Regional Mapping of Coupled Fluxes of Carbon and Water Using Multi-Sensor Fusion Techniques
NASA Astrophysics Data System (ADS)
Schull, M. A.; Anderson, M. C.; Semmens, K. A.; Yang, Y.; Gao, F.; Hain, C.; Houborg, R.
2014-12-01
In an ever-changing climate there is an increasing need to measure the fluxes of water, energy and carbon for decision makers to implement policies that will help mitigate the effects of climate change. In an effort to improve drought monitoring, water resource management and agriculture assessment capabilities, a multi-scale and multi-sensor framework for routine mapping of land-surface fluxes of water and energy at field to regional scales has been established. The framework uses the ALEXI (Atmosphere Land Exchange Inverse)/DisALEXI (Disaggregated ALEXI) suite of land-surface models forced by remotely sensed data from Landsat, MODIS (MODerate resolution Imaging Spectroradiometer), and GOES (Geostationary Operational Environmental Satellite). Land-surface temperature (LST) can be an effective substitute for in-situ surface moisture observations and a valuable metric for constraining land-surface fluxes at sub-field scales. The adopted multi-scale thermal-based land surface modeling framework facilitates regional to local downscaling of water and energy fluxes by using a combination of shortwave reflective and thermal infrared (TIR) imagery from GOES (4-10 km; hourly), MODIS (1 km; daily), and Landsat (30-100 m; bi-weekly). In this research the ALEXI/DisALEXI modeling suite is modified to incorporate carbon fluxes using a stomatal resistance module, which replaces the Priestley-Taylor latent heat approximation. In the module, canopy level nominal light-use-efficiency (βn) is the parameter that modulates the flux of water and carbon in and out of the canopy. Leaf chlorophyll (Chl) is a key parameter for quantifying variability in photosynthetic efficiency to facilitate the spatial distribution of coupled carbon and water retrievals. Spatial distribution of Chl are retrieved from Landsat (30 m) using a surface reflectance dataset as input to the REGularized canopy reFLECtance (REGFLEC) tool. The modified ALEXI/DisALEXI suite is applied to regions of rain fed and irrigated soybean and maize agricultural landscapes within the continental U.S. and flux estimates are compared with flux tower observations.
Noah-MP-Crop: Enhancing cropland representation in the community land surface modeling system
NASA Astrophysics Data System (ADS)
Liu, X.; Chen, F.; Barlage, M. J.; Zhou, G.; Niyogi, D.
2015-12-01
Croplands are important in land-atmosphere interactions and in modifying local and regional weather and climate. Despite their importance, croplands are poorly represented in the current version of the coupled Weather Research and Forecasting (WRF)/ Noah land-surface modeling system, resulting in significant surface temperature and humidity biases across agriculture- dominated regions of the United States. This study aims to improve the WRF weather forecasting and regional climate simulations during the crop growing season by enhancing the representation of cropland in the Noah-MP land model. We introduced dynamic crop growth parameterization into Noah-MP and evaluated the enhanced model (Noah-MP-Crop) at both the field and regional scales with multiple crop biomass datasets, surface fluxes and soil moisture/temperature observations. We also integrated a detailed cropland cover map into WRF, enabling the model to simulate corn and soybean field across the U.S. Great Plains. Results show marked improvement in the Noah-MP-Crop performance in simulating leaf area index (LAI), crop biomass, soil temperature, and surface fluxes. Enhanced cropland representation is not only crucial for improving weather forecasting but can also help assess potential impacts of weather variability on regional hydrometeorology and crop yields. In addition to its applications to WRF, Noah-MP-Crop can be applied in high-spatial-resolution regional crop yield modeling and drought assessments
Liu, Zhi-Hua; Chang, Yu; Chen, Hong-Wei; Zhou, Rui; Jing, Guo-Zhi; Zhang, Hong-Xin; Zhang, Chang-Meng
2008-03-01
By using geo-statistics and based on time-lag classification standard, a comparative study was made on the land surface dead combustible fuels in Huzhong forest area in Great Xing'an Mountains. The results indicated that the first level land surface dead combustible fuel, i. e., 1 h time-lag dead fuel, presented stronger spatial auto-correlation, with an average of 762.35 g x m(-2) and contributing to 55.54% of the total load. Its determining factors were species composition and stand age. The second and third levels land surface dead combustible fuel, i. e., 10 h and 100 h time-lag dead fuels, had a sum of 610.26 g x m(-2), and presented weaker spatial auto-correlation than 1 h time-lag dead fuel. Their determining factor was the disturbance history of forest stand. The complexity and heterogeneity of the factors determining the quality and quantity of forest land surface dead combustible fuels were the main reasons for the relatively inaccurate interpolation. However, the utilization of field survey data coupled with geo-statistics could easily and accurately interpolate the spatial pattern of forest land surface dead combustible fuel loads, and indirectly provide a practical basis for forest management.
NASA Technical Reports Server (NTRS)
Case, Jonathan L.; Kumar, Sujay V.; Krikishen, Jayanthi; Jedlovec, Gary J.
2011-01-01
It is hypothesized that high-resolution, accurate representations of surface properties such as soil moisture and sea surface temperature are necessary to improve simulations of summertime pulse-type convective precipitation in high resolution models. This paper presents model verification results of a case study period from June-August 2008 over the Southeastern U.S. using the Weather Research and Forecasting numerical weather prediction model. Experimental simulations initialized with high-resolution land surface fields from the NASA Land Information System (LIS) and sea surface temperature (SST) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) are compared to a set of control simulations initialized with interpolated fields from the National Centers for Environmental Prediction 12-km North American Mesoscale model. The LIS land surface and MODIS SSTs provide a more detailed surface initialization at a resolution comparable to the 4-km model grid spacing. Soil moisture from the LIS spin-up run is shown to respond better to the extreme rainfall of Tropical Storm Fay in August 2008 over the Florida peninsula. The LIS has slightly lower errors and higher anomaly correlations in the top soil layer, but exhibits a stronger dry bias in the root zone. The model sensitivity to the alternative surface initial conditions is examined for a sample case, showing that the LIS/MODIS data substantially impact surface and boundary layer properties.
NASA Technical Reports Server (NTRS)
Li, Xiaowen; Friedl, Mark; Strahler, Alan
2002-01-01
The general objectives of this project were to improve understanding of the directional emittance properties of land surfaces in the thermal infrared (TIR) region of the electro-magnetic spectrum. To accomplish these objectives our research emphasized a combination of theoretical model development and empirical studies designed to improve land surface temperature (LST) retrievals from space-borne remote sensing instruments. Following the proposal, the main tasks for this project were to: (1) Participate in field campaigns; (2) Acquire and process field, aircraft, and ancillary data; (3) Develop and refine models of LST emission; (4) Develop algorithms for LST retrieval; and (5) Explore LST retrieval methods for use in energy balance models. In general all of these objectives were addressed, and for the most part achieved. The main results from this project are described in the publications arising from this effort. We summarize our efforts related to each of the objectives.
Hyperspectral Observations of Land Surfaces Using Ground-based, Airborne, and Satellite Sensors
NASA Astrophysics Data System (ADS)
Knuteson, R. O.; Best, F. A.; Revercomb, H. E.; Tobin, D. C.
2006-12-01
The University of Wisconsin-Madison Space Science and Engineering Center (UW-SSEC) has helped pioneer the use of high spectral resolution infrared spectrometers for application to atmospheric and surface remote sensing. This paper is focused on observations of land surface infrared emission from high spectral resolution measurements collected over the past 15 years using airborne, ground-based, and satellite platforms. The earliest data was collected by the High-resolution Interferometer Sounder (HIS), an instrument designed in the 1980s for operation on the NASA ER-2 high altitude aircraft. The HIS was replaced in the late 1990s by the Scanning-HIS instrument which has flown on the NASA ER-2, WB-57, DC-8, and Scaled Composites Proteus aircraft and continues to support field campaigns, such as those for EOS Terra, Aqua, and Aura validation. Since 1995 the UW-SSEC has fielded a ground-based Atmospheric Emitted Radiance Interferometer (AERI) in a research vehicle (the AERIBAGO) which has allowed for direct field measurements of land surface emission from a height of about 16 ft above the ground. Several ground-based and aircraft campaigns were conducted to survey the region surrounding the ARM Southern Great Plains site in north central Oklahoma. The ground- based AERIBAGO has also participated in surface emissivity campaigns in the Western U.S.. Since 2002, the NASA Atmospheric InfraRed Sounder (AIRS) has provided similar measurements from the Aqua platform in an afternoon sun-synchronous polar orbit. Ground-based and airborne observations are being used to validate the land surface products derived from the AIRS observations. These cal/val activities are in preparation for similar measurements anticipated from the operational Cross-track InfraRed Sounder (CrIS) on the NPOESS Preparatory Platform (NPP), expected to be launched in 2008. Moreover, high spectral infrared observations will soon be made by the Infrared Atmospheric Sounder Interferometer (IASI) on the European MetOp platform as well as a planned series of Chinese polar orbiting satellites. The detailed understanding of the land surface infrared emission is a crucial step in the effective utilization of these advanced sounder instruments for the extraction of atmospheric composition information (esp. water vapor vertical profile) over land, which is a key goal for numerical weather prediction data assimilation.
Tian, Xin; Li, Zengyuan; Chen, Erxue; Liu, Qinhuo; Yan, Guangjian; Wang, Jindi; Niu, Zheng; Zhao, Shaojie; Li, Xin; Pang, Yong; Su, Zhongbo; van der Tol, Christiaan; Liu, Qingwang; Wu, Chaoyang; Xiao, Qing; Yang, Le; Mu, Xihan; Bo, Yanchen; Qu, Yonghua; Zhou, Hongmin; Gao, Shuai; Chai, Linna; Huang, Huaguo; Fan, Wenjie; Li, Shihua; Bai, Junhua; Jiang, Lingmei; Zhou, Ji
2015-01-01
The Complicate Observations and Multi-Parameter Land Information Constructions on Allied Telemetry Experiment (COMPLICATE) comprises a network of remote sensing experiments designed to enhance the dynamic analysis and modeling of remotely sensed information for complex land surfaces. Two types of experimental campaigns were established under the framework of COMPLICATE. The first was designed for continuous and elaborate experiments. The experimental strategy helps enhance our understanding of the radiative and scattering mechanisms of soil and vegetation and modeling of remotely sensed information for complex land surfaces. To validate the methodologies and models for dynamic analyses of remote sensing for complex land surfaces, the second campaign consisted of simultaneous satellite-borne, airborne, and ground-based experiments. During field campaigns, several continuous and intensive observations were obtained. Measurements were undertaken to answer key scientific issues, as follows: 1) Determine the characteristics of spatial heterogeneity and the radiative and scattering mechanisms of remote sensing on complex land surfaces. 2) Determine the mechanisms of spatial and temporal scale extensions for remote sensing on complex land surfaces. 3) Determine synergist inversion mechanisms for soil and vegetation parameters using multi-mode remote sensing on complex land surfaces. Here, we introduce the background, the objectives, the experimental designs, the observations and measurements, and the overall advances of COMPLICATE. As a result of the implementation of COMLICATE and for the next several years, we expect to contribute to quantitative remote sensing science and Earth observation techniques. PMID:26332035
Effect of wakes on land-atmosphere fluxes
NASA Astrophysics Data System (ADS)
Markfort, C. D.; Zhang, W.; Porte-Agel, F.; Stefan, H. G.
2011-12-01
Wakes affect land-atmosphere fluxes of momentum and scalars, including water vapor and trace gases. Canopies and bluff bodies, including forests, buildings and topography, cause boundary layer flow separation, significantly extend flow recovery, and lead to a break down of standard Monin-Obukhov similarity relationships in the atmospheric boundary layer (ABL). Wakes generated by these land surface features persist for significant distances affecting a large fraction of the Earth's terrestrial surface. This effect is currently not accounted for in land-atmosphere modeling, and little is known about how heterogeneity of wake-generating features effect land surface fluxes. Additionally flux measurements, made in wake-affected regions, do not satisfy the homogeneous requirements for the standard eddy correlation (EC) method. This phenomenon often referred to as sheltering has been shown to affect momentum and kinetic energy fluxes into lakes from the atmosphere (Markfort et al. 2010). This presentation will highlight results from controlled wind tunnel experiments of neutral and thermally stratified boundary layers, using PIV and custom x-wire/cold-wire anemometry, designed to understand how the physical structure of upstream bluff bodies or porous canopies and thermal stability affect the separation zone, boundary layer recovery and surface fluxes. We also compare these results to field measurements taken with a Doppler LiDAR in the wake of a canopy and a building. We have found that there is a nonlinear relationship between porosity and flow separation behind a canopy to clearing transition. Results will provide the basis for new parameterizations to account for wake effects on land-atmosphere fluxes and corrections for EC measurements over open fields, lakes, and wetlands.
NOAA AVHRR Land Surface Albedo Algorithm Development
NASA Technical Reports Server (NTRS)
Toll, D. L.; Shirey, D.; Kimes, D. S.
1997-01-01
The primary objective of this research is to develop a surface albedo model for the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR). The primary test site is the Konza prairie, Kansas (U.S.A.), used by the International Satellite Land Surface Climatology Project (ISLSCP) in the First ISLSCP Field Experiment (FIFE). In this research, high spectral resolution field spectrometer data was analyzed to simulate AVHRR wavebands and to derive surface albedos. Development of a surface albedo algorithm was completed by analysing a combination of satellite, field spectrometer, and ancillary data. Estimated albedos from the field spectrometer data were compared to reference albedos derived using pyranometer data. Variations from surface anisotropy of reflected solar radiation were found to be the most significant albedo-related error. Additional error or sensitivity came from estimation of a shortwave mid-IR reflectance (1.3-4.0 micro-m) using the AVHRR red and near-IR bands. Errors caused by the use of AVHRR spectral reflectance to estimate both a total visible (0.4-0.7 micro-m) and near-IR (0.7-1.3 micro-m) reflectance were small. The solar spectral integration, using the derived ultraviolet, visible, near-IR and SW mid-IR reflectivities, was not sensitive to many clear-sky changes in atmospheric properties and illumination conditions.
2014-11-03
Members of the media watch a demonstration of the Regolith Advanced Surface System Operations Robot, or RASSOR, during a media event at the automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. Tom Engler, center, in the suit, deputy director of Kennedy's Center Planning and Development, announced Moon Express Inc., of Moffett Field, California is selected to utilize Kennedy facilities for NASA's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST.
2014-11-03
CAPE CANAVERAL, Fla. - Members of the media watch a demonstration of the Regolith Advanced Surface System Operations Robot, or RASSOR, during a media event at the automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. Tom Engler, center, in the suit, deputy director of Kennedy's Center Planning and Development, announced Moon Express Inc., of Moffett Field, California is selected to utilize Kennedy facilities for NASA's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST. Photo credit: NASA/Ben Smegelsky
NASA Astrophysics Data System (ADS)
Tian, Y.; Dickinson, R. E.; Zhou, L.; Shaikh, M.
2004-10-01
This paper uses the Community Land Model (CLM2) to investigate the improvements of a new land surface data set, created from multiple high-quality collection 4 Moderate Resolution Imaging Spectroradiometer data of leaf area index (LAI), plant functional type, and vegetation continuous fields, for modeled land surface variables. The previous land surface data in CLM2 underestimate LAI and overestimate the percent cover of grass/crop over most of the global area. For snow-covered regions with abundant solar energy the increased LAI and percent cover of tree/shrub in the new data set decreases the percent cover of surface snow and increases net radiation and thus increases ground and surface (2-m) air temperature, which reduces most of the model cold bias. For snow-free regions the increased LAI and changes in the percent cover from grass/crop to tree or shrub decrease ground and surface air temperature by converting most of the increased net radiation to latent heat flux, which decreases the model warm bias. Furthermore, the new data set greatly decreases ground evaporation and increases canopy evapotranspiration over tropical forests, especially during the wet season, owing to the higher LAI and more trees in the new data set. It makes the simulated ground evaporation and canopy evapotranspiration closer to reality and also reduces the warm biases over tropical regions.
NASA Astrophysics Data System (ADS)
Zheng, Y.; Kirstetter, P. E.; Hong, Y.; Wen, Y.; Turk, J.; Gourley, J. J.
2015-12-01
One of primary uncertainties in satellite overland quantitative precipitation estimates (QPE) from passive sensors such as radiometers is the impact on the brightness temperatures by the surface land emissivity. The complexity of surface land emissivity is linked to its temporal variations (diurnal and seasonal) and spatial variations (subsurface vertical profiles of soil moisture, vegetation structure and surface temperature) translating into sub-pixel heterogeneity within the satellite field of view (FOV). To better extract the useful signal from hydrometeors, surface land emissivity needs to be determined and filtered from the satellite-measured brightness temperatures. Based on the dielectric properties of surface land cover constitutes, Microwave Polarization Differential index (MPDI) is expected to carry the composite effect of surface land properties on land surface emissivity, with a higher MPDI indicating a lower emissivity. This study analyses the dependence of MPDI to soil moisture, vegetation and surface skin temperature over 9 different land surface types. Such analysis is performed using the normalized difference vegetation index (NDVI) from MODIS, the near surface air temperature from the RAP model and ante-precedent precipitation accumulation from the Multi-Radar Multi-Sensor as surrogates for the vegetation, surface skin temperature and shallow layer soil moisture, respectively. This paper provides 1) evaluations of brightness temperature-based MPDI from the TRMM and GPM Microwave Imagers in both raining and non-raining conditions to test the dependence of MPDI to precipitation; 2) comparisons of MPDI categorized into instantly before, during and immediately after selected precipitation events to examine the impact of modest-to-heavy precipitation on the spatial pattern of MPDI; 3) inspections of relationship between MPDI versus rain fraction and rain rate within the satellite sensors FOV to investigate the behaviors of MPDI in varying precipitation conditions; 4) analysis of discrepancies of MPDI over 10.65, 19.35, 37 and 85.8 GHz to identify the sensitivity of MPDS to microwave wavelengths.
Influence of Agricultural Practice on Surface Temperature
NASA Astrophysics Data System (ADS)
Czajkowski, K.; Ault, T.; Hayase, R.; Benko, T.
2006-12-01
Changes in land uses/covers can have a significant effect on the temperature of the Earth's surface. Agricultural fields exhibit a significant change in land cover within a single year and from year to year as different crops are planted. These changes in agricultural practices including tillage practice and crop type influence the energy budget as reflected in differences in surface temperature. In this project, Landsat 5 and 7 imagery were used to investigate the influence of crop type and tillage practice on surface temperature in Iowa and NW Ohio. In particular, the three crop rotation of corn, soybeans and wheat, as well as no-till, conservation tillage and tradition tillage methods, were investigated. Crop type and conservation tillage practices were identified using supervised classification. Student surface temperature observations from the GLOBE program were used to correct for the effects of the atmosphere for some of the satellite thermal observations. Students took surface temperature observations in field sites near there schools using hand- held infrared thermometers.
NASA Astrophysics Data System (ADS)
Song, J.; Wang, Z.
2013-12-01
Studying urban land-atmospheric interactions by coupling an urban canopy model with a single column atmospheric models Jiyun Song and Zhi-Hua Wang School of Sustainable Engineering and the Built Environment, Arizona State University, PO Box 875306, Tempe, AZ 85287-5306 Landuse landcover changes in urban area will modify surface energy budgets, turbulent fluxes as well as dynamic and thermodynamic structures of the overlying atmospheric boundary layer (ABL). In order to study urban land-atmospheric interactions, we coupled a single column atmospheric model (SCM) to a cutting-edge single layer urban canopy model (SLUCM). Modification of surface parameters such as the fraction of vegetation and engineered pavements, thermal properties of building and pavement materials, and geometrical features of street canyon, etc. in SLUCM dictates the evolution of surface balance of energy, water and momentum. The land surface states then provide lower boundary conditions to the overlying atmosphere, which in turn modulates the modification of ABL structure as well as vertical profiles of temperature, humidity, wind speed and tracer gases. The coupled SLUCM-SCM model is tested against field measurements of surface layer fluxes as well as profiles of temperature and humidity in the mixed layer under convective conditions. After model test, SLUCM-SCM is used to simulate the effect of changing urban land surface conditions on the evolution of ABL structure and dynamics. Simulation results show that despite the prescribed atmospheric forcing, land surface states impose significant impact on the physics of the overlying vertical atmospheric layer. Overall, this numerical framework provides a useful standalone modeling tool to assess the impacts of urban land surface conditions on the local hydrometeorology through land-atmospheric interactions. It also has potentially far-reaching implications to urban ecohydrological services for cities under future expansion and climate challenges.
surface temperature field. If these are eliminated, which is relatively simple over a water surface, the differences between calculated and measured...divergences at these levels is less than 20%, on the average. The relative variation of the divergence with height is somewhat greater over water than over land, due to the different temperature profiles. (Author)
NASA Astrophysics Data System (ADS)
Leomo, S.; Ginting, S.; Sabaruddin, L.; Tufaila, M.; Muhidin
2018-02-01
The Endanga basin is one part of the Konaweeha watershed located in South Konawe, Southeast Sulawesi Province, covering an area of 1,353.67 hectares. The land use patterns in Endanga Watershed contained forests, shrubs, oil palm plantations, pepper fields, and cultivated fields of field rice, corn monoculture and intercropping of peanuts and corn. This watershed needs serious attention because most of its territory is on slope of 15-40%, with erosion hazard levels (EHL) varying from mild erosion to severe erosion. The loss of organic carbon (C-organic) soil is measured from the soil carried along with the surface stream and into the reservoir on various land uses. The result measurement of C-organic soil loss on forest land use is 14.02 kg ha-1, shrubs land 22.71 kg ha-1, oil palm 151.32 kg ha-1, pepper garden 93.69 kg ha-1, field rice 313.80 kg.ha-1, monoculture of maize 142.44 kg ha-1, intercropped maize and corn 51.10 kg ha-1 and open land 1,909.16 kg ha-1. The forest land and shrubs is best in conserving soil C-organic, but economically unfavorable for the community, so land use pattern for intercropping and pepper plantation can be used for soil C-organic conservation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eddleman, L.E.
1980-01-01
Shrubs are an important component of plant communities in southeastern Montana. Re-establishment of the majority of native shrubs by seed on surface coal mine lands has not been generally successful. Field plantings at the Rosebud Mine of 25 shrub and half-shrub species were initiated in 1978 using seed from native populations. Three species Atriplex canescens, Atriplex nuttallii and Ceratoids lanata establish numerous seedlings in both wet and dry years. No emergence was obtained from 12 species.
NASA Astrophysics Data System (ADS)
AllahTavakoli, Y.; Safari, A.; Ardalan, A.; Bahroudi, A.
2015-12-01
The current research provides a method for tracking near-surface mass-density anomalies via using only land-based gravity data, which is based on a special version of Poisson's Partial Differential Equation (PDE) of the gravitational field at Earth's surface. The research demonstrates how the Poisson's PDE can provide us with a capability to extract the near-surface mass-density anomalies from land-based gravity data. Herein, this version of the Poisson's PDE is mathematically introduced to the Earth's surface and then it is used to develop the new method for approximating the mass-density via derivatives of the Earth's gravitational field (i.e. via the gradient tensor). Herein, the author believes that the PDE can give us new knowledge about the behavior of the Earth's gravitational field at the Earth's surface which can be so useful for developing new methods of Earth's mass-density determination. In a case study, the proposed method is applied to a set of gravity stations located in the south of Iran. The results were numerically validated via certain knowledge about the geological structures in the area of the case study. Also, the method was compared with two standard methods of mass-density determination. All the numerical experiments show that the proposed approach is well-suited for tracking near-surface mass-density anomalies via using only the gravity data. Finally, the approach is also applied to some petroleum exploration studies of salt diapirs in the south of Iran.
NASA Astrophysics Data System (ADS)
Illangasekare, T. H.; Sakaki, T.; Smits, K. M.; Limsuwat, A.; Terrés-Nícoli, J. M.
2008-12-01
Understanding the dynamics of soil moisture distribution near the ground surface is of interest in various applications involving land-atmospheric interaction, evaporation from soils, CO2 leakage from carbon sequestration, vapor intrusion into buildings, and land mine detection. Natural soil heterogeneity in combination with water and energy fluxes at the soil surface creates complex spatial and temporal distributions of soil moisture. Even though considerable knowledge exists on how soil moisture conditions change in response to flux and energy boundary conditions, emerging problems involving land atmospheric interactions require the quantification of soil moisture variability both at high spatial and temporal resolutions. The issue of up-scaling becomes critical in all applications, as in general, field measurements are taken at sparsely distributed spatial locations that require assimilation with measurements taken using remote sensing technologies. It is our contention that the knowledge that will contribute to both improving our understanding of the fundamental processes and practical problem solution cannot be obtained easily in the field due to a number of constraints. One of these basic constraints is the inability to make measurements at very fine spatial scales at high temporal resolutions in naturally heterogeneous field systems. Also, as the natural boundary conditions at the land/atmospheric interface are not controllable in the field, even in pilot scale studies, the developed theories and tools cannot be validated for the diversity of conditions that could be expected in the field. Intermediate scale testing using soil tanks packed to represent different heterogeneous test configurations provides an attractive and cost effective alternative to investigate a class of problems involving the shallow unsaturated zone. In this presentation, we will discuss the advantages and limitations of studies conducted in both two and three dimensional intermediate scale test systems together with instrumentation and measuring techniques. The features and capabilities of a new coupled porous media/climate wind tunnel test system that allows for the study of near surface unsaturated soil moisture conditions under climate boundary conditions will also be presented with the goal of exploring opportunities to use such a facility to study some of the multi-scale problems in the near surface unsaturated zone.
Mouth of the Amazon River as seen from STS-58
1993-10-30
STS058-107-083 (18 Oct.-1 Nov. 1993) --- A near-nadir view of the mouth of the Amazon River, that shows all signs of being a relatively healthy system, breathing and exhaling. The well-developed cumulus field over the forested areas on both the north and south sides of the river (the view is slightly to the west) shows that good evapotranspiration is underway. The change in the cloud field from the moisture influx from the Atlantic (the cloud fields over the ocean are parallel to the wind direction) to perpendicular cloud fields over the land surface are normal. This change in direction is caused by the increased surface roughness over the land area. The plume of the river, although turbid, is no more or less turbid than it has been reported since the Portuguese first rounded Brasil's coast at the end of the 15th Century.
Effect of long-term application of biosolids for land reclamation on surface water chemistry.
Tian, G; Granato, T C; Pietz, R I; Carlson, C R; Abedin, Z
2006-01-01
Biosolids are known to have a potential to restore degraded land, but the long-term impacts of this practice on the environment, including water quality, still need to be evaluated. The surface water chemistry (NO3-, NH4+, and total P, Cd, Cu, and Hg) was monitored for 31 yr from 1972 to 2002 in a 6000-ha watershed at Fulton County, Illinois, where the Metropolitan Water Reclamation District of Greater Chicago was restoring the productivity of strip-mined land using biosolids. The mean cumulative loading rates during the past 31 yr were 875 dry Mg ha(-1) for 1120-ha fields in the biosolids-amended watershed and 4.3 dry Mg ha(-1) for the 670-ha fields in the control watershed. Biosolids were injected into mine spoil fields as liquid fertilizer from 1972 to 1985, and incorporated as dewatered cake from 1980 to 1996 and air-dried solids from 1987 to 2002. The mean annual loadings of nutrients and trace elements from biosolids in 1 ha were 735 kg N, 530 kg P, 4.5 kg Cd, 30.7 kg Cu, and 0.11 kg Hg in the fields of the biosolids-amended watershed, and negligible in the fields of the control watershed. Sampling of surface water was conducted monthly in the 1970s, and three times per year in the 1980s and 1990s. The water samples were collected from 12 reservoirs and 2 creeks receiving drainage from the fields in the control watershed, and 8 reservoirs and 4 creeks associated with the fields in the biosolids-amended watershed for the analysis of NO3- -N (including NO2- N), NH4+-N, and total P, Cd, Cu, and Hg. Compared to the control (0.18 mg L(-1)), surface water NO3- -N in the biosolids-amended watershed (2.23 mg L(-1)) was consistently higher; however, it was still below the Illinois limit of 10 mg L(-1) for public and food-processing water supplies. Biosolids applications had a significant effect on mean concentrations of ammonium N (0.11 mg L(-1) for control and 0.24 mg L(-1) for biosolids) and total P (0.10 mg L(-1) for control and 0.16 mg L(-1) for biosolids) in surface water. Application of biosolids did not increase the concentrations of Cd and Hg in surface water. The elevation of Cu in surface water with biosolids application only occurred in some years of the first decade, when land-applied sludges contained high concentrations of trace metals, including Cu. In fact, following the promulgation of 40 CFR Part 503, the concentrations of all three metals fell below the method detection level (MDL) in surface water for nearly all samplings. Nitrate in the surface water tends to be higher in spring, and ammonium, total P, and total Hg in summer and fall. Mean nitrate, ammonium, and total phosphorus concentrations were found to be greater in creeks than reservoirs. The results indicate that application of biosolids for land reclamation at high loading rates from 1972 to 2002, with adequate runoff and soil erosion control, had only a minor impact on surface water quality.
Calibration, navigation, and registration of MAMS data for FIFE
NASA Technical Reports Server (NTRS)
Jedlovec, G. J.; Atkinson, R. J.
1993-01-01
The International Satellite Land Surface Climatology Project (ISLSCP) was conducted to study the interaction of the atmosphere with the land surface and the research problems associated with the interpretation of satellite data over the Earth's land surface. The experimental objectives of the First ISLSCP Field Experiment (FIFE) were the simultaneous acquisition of satellite, atmospheric, and surface data and to use these data to understand the processes controlling energy/mass exchange at the surface. The experiment site is a 15 x 15 km area southeast of Manhattan, Kansas, intersected by Interstate 70 and Kansas highway 177. The Konza Prairie portion is 5 x 5 km and is a controlled experiment site consisting primarily of native tall grass prairie vegetation. The remainder of the site is grazing and farm land with trees along creek beds that are scattered over the area. Airborne multispectral imagery from the Multispectral Atmospheric Mapping Sensor (MAMS) was collected over this region on two days during Intensive Field Campaign-1 (1FC-1) to study the time and space variability of remotely-sensed geophysical parameters. These datasets consist of multiple overflights covering about a 60-min period during late morning on June 4, 1987 and shortly after dark on the following day. Image data from each overpass were calibrated and Earth located with respect to each other using aircraft inertial navigation system parameters and ground control points. These were the first MAMS flights made with 10-bit thermal data.
NASA Technical Reports Server (NTRS)
Lawston, Patricia M.; Santanello, Joseph A.; Rodell, Matthew; Franz, Trenton E.
2017-01-01
Irrigation increases soil moisture, which in turn controls water and energy fluxes from the land surface to the10 planetary boundary layer and determines plant stress and productivity. Therefore, developing a realistic representation of irrigation is critical to understanding land-atmosphere interactions in agricultural areas. Irrigation parameterizations are becoming more common in land surface models and are growing in sophistication, but there is difficulty in assessing the realism of these schemes, due to limited observations (e.g., soil moisture, evapotranspiration) and scant reporting of irrigation timing and quantity. This study uses the Noah land surface model run at high resolution within NASAs Land15 Information System to assess the physics of a sprinkler irrigation simulation scheme and model sensitivity to choice of irrigation intensity and greenness fraction datasets over a small, high resolution domain in Nebraska. Differences between experiments are small at the interannual scale but become more apparent at seasonal and daily time scales. In addition, this study uses point and gridded soil moisture observations from fixed and roving Cosmic Ray Neutron Probes and co-located human practice data to evaluate the realism of irrigation amounts and soil moisture impacts simulated by the model. Results20 show that field-scale heterogeneity resulting from the individual actions of farmers is not captured by the model and the amount of irrigation applied by the model exceeds that applied at the two irrigated fields. However, the seasonal timing of irrigation and soil moisture contrasts between irrigated and non-irrigated areas are simulated well by the model. Overall, the results underscore the necessity of both high-quality meteorological forcing data and proper representation of irrigation foraccurate simulation of water and energy states and fluxes over cropland.
Multimedia Sampling During The Application Of Biosolids On A Land Test Site (Presentation)
The goal of this research study was to evaluate air and soil sampling methods and analytical techniques for commercial land application of biosolids. Biosolids, were surface applied at agronomic rates to an agricultural field. During the period of August 2004 to January 2005, 3...
Application of the Nimbus 5 ESMR to rainfall detection over land surfaces
NASA Technical Reports Server (NTRS)
Meneely, J. M.
1975-01-01
The ability of the Nimbus 5 Electrically Scanning Microwave Radiometer (ESMR) to detect rainfall over land surfaces was evaluated. The ESMR brightness temperatures (Tb sub B) were compared with rainfall reports from climatological stations for a limited number of rain events over portions of the U.S. The greatly varying emissivity of land surfaces precludes detection of actively raining areas. Theoretical calculations using a ten-layer atmospheric model showed this to be an expected result. Detection of rain which had fallen was deemed feasible over certain types of land surfaces by comparing the Tb sub B fields before and after the rain fell. This procedure is reliable only over relatively smooth terrain having a substantial fraction of bare soil, such as exists in major agricultural regions during the dormant or early growing seasons. Soil moisture budgets were computed at selected sites to show how the observed emissivity responded to changes in the moisture content of the upper soil zone.
NASA Astrophysics Data System (ADS)
Williams, J. L.; Maxwell, R. M.; Delle Monache, L.
2012-12-01
Wind power is rapidly gaining prominence as a major source of renewable energy. Harnessing this promising energy source is challenging because of the chaotic nature of wind and its propensity to change speed and direction over short time scales. Accurate forecasting tools are critical to support the integration of wind energy into power grids and to maximize its impact on renewable energy portfolios. Numerous studies have shown that soil moisture distribution and land surface vegetative processes profoundly influence atmospheric boundary layer development and weather processes on local and regional scales. Using the PF.WRF model, a fully-coupled hydrologic and atmospheric model employing the ParFlow hydrologic model with the Weather Research and Forecasting model coupled via mass and energy fluxes across the land surface, we have explored the connections between the land surface and the atmosphere in terms of land surface energy flux partitioning and coupled variable fields including hydraulic conductivity, soil moisture and wind speed, and demonstrated that reductions in uncertainty in these coupled fields propagate through the hydrologic and atmospheric system. We have adapted the Data Assimilation Research Testbed (DART), an implementation of the robust Ensemble Kalman Filter data assimilation algorithm, to expand our capability to nudge forecasts produced with the PF.WRF model using observational data. Using a semi-idealized simulation domain, we examine the effects of assimilating observations of variables such as wind speed and temperature collected in the atmosphere, and land surface and subsurface observations such as soil moisture on the quality of forecast outputs. The sensitivities we find in this study will enable further studies to optimize observation collection to maximize the utility of the PF.WRF-DART forecasting system.
What determines transitions between energy- and moisture-limited evaporative regimes?
NASA Astrophysics Data System (ADS)
Haghighi, E.; Gianotti, D.; Akbar, R.; Salvucci, G.; Entekhabi, D.
2017-12-01
The relationship between evaporative fraction (EF) and soil moisture (SM) has traditionally been used in atmospheric and land-surface modeling communities to determine the strength of land-atmosphere coupling in the context of the dominant evaporative regime (energy- or moisture-limited). However, recent field observations reveal that EF-SM relationship is not unique and could vary substantially with surface and/or meteorological conditions. This implies that conventional EF-SM relationships (exclusive of surface and meteorological conditions) are embedded in more complex dependencies and that in fact it is a multi-dimensional function. To fill the fundamental knowledge gaps on the important role of varying surface and meteorological conditions not accounted for by the traditional evaporative regime conceptualization, we propose a generalized EF framework using a mechanistic pore-scale model for evaporation and energy partitioning over drying soil surfaces. Nonlinear interactions among the components of the surface energy balance are reflected in a critical SM that marks the onset of transition between energy- and moisture-limited evaporative regimes. The new generalized EF framework enables physically based estimates of the critical SM, and provides new insights into the origin of land surface EF partitioning linked to meteorological input data and the evolution of land surface temperature during surface drying that affect the relative efficiency of surface energy balance components. Our results offer new opportunities to advance predictive capabilities quantifying land-atmosphere coupling for a wide range of present and projected meteorological input data.
Land-Surface Subsidence and Open Bedrock Fractures in the Tully Valley, Onondaga County, New York
Hackett, William R.; Gleason, Gayle C.; Kappel, William M.
2009-01-01
Open bedrock fractures were mapped in and near two brine field areas in Tully Valley, New York. More than 400 open fractures and closed joints were mapped for dimension, orientation, and distribution along the east and west valley walls adjacent to two former brine fields. The bedrock fractures are as much as 2 feet wide and over 50 feet deep, while linear depressions in the soil, which are 3 to 10 feet wide and 3 to 6 feet deep, indicate the presence of open bedrock fractures below the soil. The fractures are probably the result of solution mining of halite deposits about 1,200 feet below the land surface.
Scaling, soil moisture and evapotranspiration in runoff models
NASA Technical Reports Server (NTRS)
Wood, Eric F.
1993-01-01
The effects of small-scale heterogeneity in land surface characteristics on the large-scale fluxes of water and energy in the land-atmosphere system has become a central focus of many of the climatology research experiments. The acquisition of high resolution land surface data through remote sensing and intensive land-climatology field experiments (like HAPEX and FIFE) has provided data to investigate the interactions between microscale land-atmosphere interactions and macroscale models. One essential research question is how to account for the small scale heterogeneities and whether 'effective' parameters can be used in the macroscale models. To address this question of scaling, the probability distribution for evaporation is derived which illustrates the conditions for which scaling should work. A correction algorithm that may appropriate for the land parameterization of a GCM is derived using a 2nd order linearization scheme. The performance of the algorithm is evaluated.
NASA Astrophysics Data System (ADS)
Garay, M. J.; Bull, M. A.; Witek, M. L.; Diner, D. J.; Seidel, F.
2017-12-01
Since early 2000, the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite has been providing operational Level 2 (swath-based) aerosol optical depth (AOD) and particle property retrievals at 17.6 km spatial resolution and atmospherically corrected land surface products at 1.1 km resolution. A major, multi-year development effort has led to the release of updated operational MISR Level 2 aerosol and land surface retrieval products. The spatial resolution of the aerosol product has been increased to 4.4 km, allowing more detailed characterization of aerosol spatial variability, especially near local sources and in urban areas. The product content has been simplified and updated to include more robust measures of retrieval uncertainty and other fields to benefit users. The land surface product has also been updated to incorporate the Version 23 aerosol product as input and to improve spatial coverage, particularly over mountainous terrain and snow/ice-covered surfaces. We will describe the major upgrades incorporated in Version 23, present validation of the aerosol product, and describe some of the applications enabled by these product updates.
Magnetism and the interior of the moon. [measured at Apollo landing sites
NASA Technical Reports Server (NTRS)
Dyal, P.; Parkin, C. W.; Daily, W. D.
1974-01-01
During the time period 1961-1972 eleven magnetometers were sent to the moon. The results of lunar magnetometer data analysis are reviewed, with emphasis on the lunar interior. Magnetic fields have been measured on the lunar surface at the Apollo 12, 14, 15, and 16 landing sites. The remanent field values at these sites are given. Satellite and surface measurements show strong evidence that the lunar crust is magnetized over much of the lunar globe. The origin of the lunar remanent field is not yet satisfactorily understood; several source models are presented. Simultaneous data from the Apollo 12 lunar surface magnetometer and the Explorer 35 Ames magnetometer are used to construct a wholemoon hysteresis curve, from which the global lunar permeability is determined. Total iron abundance is calculated for two assumed compositional models of the lunar interior. Other lunar models with a small iron core and with a shallow iron-rich layer are also discussed in light of the measured global permeability.
NASA Ames Celebrates Curiosity Rover's Landing on Mars (Reporter Package)
2012-08-08
Nearly 7,000 people came to NASA Ames Research Center, Moffett Field, Calif., to watch the Mars Science Laboratory rover Curiosity land on Mars. A full day's worth of activities and discussions with local Mars experts informed attendees about the contributions NASA Ames made to the mission. The highlight of the event was the live NASA TV broadcast of MSL's entry, descent and landing on the Martian surface.
Estimating surface fluxes over middle and upper streams of the Heihe River Basin with ASTER imagery
NASA Astrophysics Data System (ADS)
Ma, W.; Ma, Y.; Hu, Z.; Su, B.; Wang, J.; Ishikawa, H.
2009-06-01
Surface fluxes are important boundary conditions for climatological modeling and the Asian monsoon system. Recent availability of high-resolution, multi-band imagery from the ASTER (Advanced Space-borne Thermal Emission and Reflection Radiometer) sensor has enabled us to estimate surface fluxes to bridge the gap between local scale flux measurements using micrometeorological instruments and regional scale land-atmosphere exchanges of water and heat fluxes that are fundamental for the understanding of the water cycle in the Asian monsoon system. A Surface Energy Balance System (SEBS) method based on ASTER data and field observations has been proposed and tested for deriving net radiation flux (Rn), soil heat flux (G0), sensible heat flux (H) and latent heat flux (λ E) over heterogeneous land surface in this paper. As a case study, the methodology was applied to the experimental area of the WATER (Watershed Allied Telemetry Experimental Research), located at the mid-to-upstream sections of the Heihe River, northwest China. The ASTER data of 3 May and 4 June in 2008 was used in this paper for the case of mid-to-upstream sections of the Heihe River Basin. To validate the proposed methodology, the ground-measured land surface heat fluxes (net radiation flux (Rn), soil heat flux (G0), sensible heat flux (H) and latent heat flux (λ E)) were compared to the ASTER derived values. The results show that the derived surface variables and land surface heat fluxes in different months over the study area are in good accordance with the land surface status. It is therefore concluded that the proposed methodology is successful for the retrieval of land surface heat fluxes using the ASTER data and filed observation over the study area.
Simulating crop phenology in the Community Land Model and its impact on energy and carbon fluxes
USDA-ARS?s Scientific Manuscript database
A reasonable representation of crop phenology and biophysical processes in land surface models is necessary to accurately simulate energy, water and carbon budgets at the field, regional, and global scales. However, the evaluation of crop models that can be coupled to earth system models is relative...
Radiation fluxes at the FIFE site
NASA Technical Reports Server (NTRS)
Walter-Shea, Elizabeth A.; Blad, Blaine L.; Zara, Pedro; Vining, Roel; Hays, Cynthia J.; Mesarch, Mark A.
1993-01-01
The main objective of the International Satellite Land Surface Climatology Project (ISLSCP) has been stated as 'the development of techniques that may be applied to satellite observations of the radiation reflected and emitted from the Earth to yield quantitative information concerning land surface climatological conditions'. The major field study, FIFE (the First ISLSCP Field Experiment), was conducted in 1987-89 to accomplish this objective. Four intensive field campaigns (IFC's) were carried out in 1987 and one in 1989. Factors contributing to observed reflected radiation from the FIFE site must be understood before the radiation observed by satellites can be used to quantify surface processes. Our last report (Walter-Shea et al., 1992b) focused on slope effects on incoming and outgoing shortwave radiation and net radiation from data collected in 1989. We report here on the final analysis of the slope data as well as results from thermal radiation studies conducted during the FIFE experiment. The specific areas reported are the following: (1) analysis of slope effects on measured reflectance values and estimates of surface albedo; (2) using remotely-measured surface temperatures as a means of estimating sensible heat flux from the Konza Prairie; (3) extracting canopy temperatures from remotely-measured composite surface temperatures; (4) modeling the measured composite temperature of partially vegetated surfaces; and (5) estimating gap distribution in partially vegetated surfaces from reflectance measurements.
Radiation fluxes at the FIFE site. Final report, 1 January 1991-31 July 1992
DOE Office of Scientific and Technical Information (OSTI.GOV)
Walter-Shea, E.A.; Blad, B.L.; Zara, P.
1993-01-01
The main objective of the International Satellite Land Surface Climatology Project (ISLSCP) has been stated as 'the development of techniques that may be applied to satellite observations of the radiation reflected and emitted from the Earth to yield quantitative information concerning land surface climatological conditions'. The major field study, FIFE (the First ISLSCP Field Experiment), was conducted in 1987-89 to accomplish this objective. Four intensive field campaigns (IFC's) were carried out in 1987 and one in 1989. Factors contributing to observed reflected radiation from the FIFE site must be understood before the radiation observed by satellites can be used tomore » quantify surface processes. Our last report (Walter-Shea et al.) focused on slope effects on incoming and outgoing shortwave radiation and net radiation from data collected in 1989. We report here on the final analysis of the slope data as well as results from thermal radiation studies conducted during the FIFE experiment. The specific areas reported are the following: (1) analysis of slope effects on measured reflectance values and estimates of surface albedo; (2) using remotely-measured surface temperatures as a means of estimating sensible heat flux from the Konza Prairie; (3) extracting canopy temperatures from remotely-measured composite surface temperatures; (4) modeling the measured composite temperature of partially vegetated surfaces; and (5) estimating gap distribution in partially vegetated surfaces from reflectance measurements.« less
Modeling Land Use Change In A Tropical Environment Using Similar Hydrologic Response Units
NASA Astrophysics Data System (ADS)
Guardiola-Claramonte, M.; Troch, P.
2006-12-01
Montane mainland South East Asia comprises areas of great biological and cultural diversity. Over the last decades the region has overcome an important conversion from traditional agriculture to cash crop agriculture driven by regional and global markets. Our study aims at understanding the hydrological implications of these land use changes at the catchment scale. In 2004, networks of hydro-meteorological stations observing water and energy fluxes were installed in two 70 km2 catchments in Northern Thailand (Chiang Mai Province) and Southern China (Yunnan Province). In addition, a detailed soil surveying campaign was done at the moment of instrument installation. Land use is monitored periodically using satellite data. The Thai catchment is switching from small agricultural fields to large extensions of cash crops. The Chinese catchment is replacing the traditional forest for rubber plantations. A first comparative study based on catchments' geomorphologic characteristics, field observations and rainfall-runoff response revealed the dominant hydrologic processes in the catchments. Land use information is then translated into three different Hydrologic Response Units (HRU): rice paddies, pervious and impervious surfaces. The pervious HRU include different land uses such as different stages of forest development, rubber plantations, and agricultural fields; the impervious ones are urban areas, roads and outcrops. For each HRU a water and energy balance model is developed incorporating field observed hydrologic processes, measured field parameters, and literature-based vegetation and soil parameters to better describe the root zone, surface and subsurface flow characteristics without the need of further calibration. The HRU water and energy balance models are applied to single hillslopes and their integrated hydrologic response are compared for different land covers. Finally, the response of individual hillslopes is routed through the channel network to represent each of the basins. Results from the model are compared to measured catchment-scale water and energy fluxes.
Evaluation of MuSyQ land surface albedo based on LAnd surface Parameters VAlidation System (LAPVAS)
NASA Astrophysics Data System (ADS)
Dou, B.; Wen, J.; Xinwen, L.; Zhiming, F.; Wu, S.; Zhang, Y.
2016-12-01
satellite derived Land surface albedo is an essential climate variable which controls the earth energy budget and it can be used in applications such as climate change, hydrology, and numerical weather prediction. However, the accuracy and uncertainty of surface albedo products should be evaluated with a reliable reference truth data prior to applications. A new comprehensive and systemic project of china, called the Remote Sensing Application Network (CRSAN), has been launched recent years. Two subjects of this project is developing a Multi-source data Synergized Quantitative Remote Sensin g Production System ( MuSyQ ) and a Web-based validation system named LAnd surface remote sensing Product VAlidation System (LAPVAS) , which aims to generate a quantitative remote sensing product for ecosystem and environmental monitoring and validate them with a reference validation data and a standard validation system, respectively. Land surface BRDF/albedo is one of product datasets of MuSyQ which has a pentad period with 1km spatial resolution and is derived by Multi-sensor Combined BRDF Inversion ( MCBI ) Model. In this MuSyQ albedo evaluation, a multi-validation strategy is implemented by LAPVAS, including directly and multi-scale validation with field measured albedo and cross validation with MODIS albedo product with different land cover. The results reveal that MuSyQ albedo data with a 5-day temporal resolution is in higher sensibility and accuracy during land cover change period, e.g. snowing. But results without regard to snow or changed land cover, MuSyQ albedo generally is in similar accuracy with MODIS albedo and meet the climate modeling requirement of an absolute accuracy of 0.05.
Modeled impact of anthropogenic land cover change on climate
Findell, K.L.; Shevliakova, E.; Milly, P.C.D.; Stouffer, R.J.
2007-01-01
Equilibrium experiments with the Geophysical Fluid Dynamics Laboratory's climate model are used to investigate the impact of anthropogenic land cover change on climate. Regions of altered land cover include large portions of Europe, India, eastern China, and the eastern United States. Smaller areas of change are present in various tropical regions. This study focuses on the impacts of biophysical changes associated with the land cover change (albedo, root and stomatal properties, roughness length), which is almost exclusively a conversion from forest to grassland in the model; the effects of irrigation or other water management practices and the effects of atmospheric carbon dioxide changes associated with land cover conversion are not included in these experiments. The model suggests that observed land cover changes have little or no impact on globally averaged climatic variables (e.g., 2-m air temperature is 0.008 K warmer in a simulation with 1990 land cover compared to a simulation with potential natural vegetation cover). Differences in the annual mean climatic fields analyzed did not exhibit global field significance. Within some of the regions of land cover change, however, there are relatively large changes of many surface climatic variables. These changes are highly significant locally in the annual mean and in most months of the year in eastern Europe and northern India. They can be explained mainly as direct and indirect consequences of model-prescribed increases in surface albedo, decreases in rooting depth, and changes of stomatal control that accompany deforestation. ?? 2007 American Meteorological Society.
NASA Technical Reports Server (NTRS)
Matthews, E.
1984-01-01
A simple method was developed for improved prescription of seasonal surface characteristics and parameterization of land-surface processes in climate models. This method, developed for the Goddard Institute for Space Studies General Circulation Model II (GISS GCM II), maintains the spatial variability of fine-resolution land-cover data while restricting to 8 the number of vegetation types handled in the model. This was achieved by: redefining the large number of vegetation classes in the 1 deg x 1 deg resolution Matthews (1983) vegetation data base as percentages of 8 simple types; deriving roughness length, field capacity, masking depth and seasonal, spectral reflectivity for the 8 types; and aggregating these surface features from the 1 deg x 1 deg resolution to coarser model resolutions, e.g., 8 deg latitude x 10 deg longitude or 4 deg latitude x 5 deg longitude.
NASA Astrophysics Data System (ADS)
Ma, W.; Ma, Y.; Hu, Z.; Zhong, L.
2017-12-01
In this study, a land-atmosphere model was initialized by ingesting AMSR-E products, and the results were compared with the default model configuration and with in situ long-term CAMP/Tibet observations. Firstly our field observation sites will be introduced based on ITPCAS (Institute of Tibetan Plateau Research, Chinese Academy of Sciences). Then, a land-atmosphere model was initialized by ingesting AMSR-E products, and the results were compared with the default model configuration and with in situ long-term CAMP/Tibet observations. The differences between the AMSR-E initialized model runs with the default model configuration and in situ data showed an apparent inconsistency in the model-simulated land surface heat fluxes. The results showed that the soil moisture was sensitive to the specific model configuration. To evaluate and verify the model stability, a long-term modeling study with AMSR-E soil moisture data ingestion was performed. Based on test simulations, AMSR-E data were assimilated into an atmospheric model for July and August 2007. The results showed that the land surface fluxes agreed well with both the in situ data and the results of the default model configuration. Therefore, the simulation can be used to retrieve land surface heat fluxes from an atmospheric model over the Tibetan Plateau.
NASA Astrophysics Data System (ADS)
Yang, Junhua; Ji, Zhenming; Chen, Deliang; Kang, Shichang; Fu, Congshen; Duan, Keqin; Shen, Miaogen
2018-06-01
The application of satellite radiance assimilation can improve the simulation of precipitation by numerical weather prediction models. However, substantial quantities of satellite data, especially those derived from low-level (surface-sensitive) channels, are rejected for use because of the difficulty in realistically modeling land surface emissivity and energy budgets. Here, we used an improved land use and leaf area index (LAI) dataset in the WRF-3DVAR assimilation system to explore the benefit of using improved quality of land surface information to improve rainfall simulation for the Shule River Basin in the northeastern Tibetan Plateau as a case study. The results for July 2013 show that, for low-level channels (e.g., channel 3), the underestimation of brightness temperature in the original simulation was largely removed by more realistic land surface information. In addition, more satellite data could be utilized in the assimilation because the realistic land use and LAI data allowed more satellite radiance data to pass the deviation test and get used by the assimilation, which resulted in improved initial driving fields and better simulation in terms of temperature, relative humidity, vertical convection, and cumulative precipitation.
Morton, R.A.; Bernier, J.C.; Barras, J.A.
2006-01-01
Analysis of remote images, elevation surveys, stratigraphic cross-sections, and hydrocarbon production data demonstrates that extensive areas of wetland loss in the northern Gulf Coast region of the United States were associated with large-volume fluid production from mature petroleum fields. Interior wetland losses at many sites in coastal Louisiana and Texas are attributed largely to accelerated land subsidence and fault reactivation induced by decreased reservoir pressures as a result of rapid or prolonged extraction of gas, oil, and associated brines. Evidence that moderately-deep hydrocarbon production has induced land-surface subsidence and reactivated faults that intersect the surface include: (1) close temporal and spatial correlation of fluid production with surficial changes including rapid subsidence of wetland sediments near producing fields, (2) measurable offsets of shallow strata across the zones of wetland loss, (3) large reductions in subsurface pressures where subsidence rates are high, (4) coincidence of orientation and direction of displacement between surface fault traces and faults that bound the reservoirs, and (5) accelerated subsidence rates near producing fields compared to subsidence rates in surrounding areas or compared to geological rates of subsidence. Based on historical trends, subsidence rates in the Gulf Coast region near producing fields most likely will decrease in the future because most petroleum fields are nearly depleted. Alternatively, continued extraction of conventional energy resources as well as potential production of alternative energy resources (geopressured-geothermal fluids) in the Gulf Coast region could increase subsidence and land losses and also contribute to inundation of areas of higher elevation. ?? Springer-Verlag 2006.
NASA Technical Reports Server (NTRS)
Tyahla, Lori J.; Lopez, Raul E.
1994-01-01
The effect of surface conductivity on the peak magnetic field radiated by the first return stroke in cloud-to-ground lightning was investigated by comparing the peak magnetic fields from return strokes that struck water with those that struck land. The data were obtained from a network of three gated, wideband magnetic direction finders (DFs) at the NASA Kennedy Space Center during the summer of 1985. Two geographical areas that were equidistant from two of the direction finders were compared where the flash distances ranged from approximately 40 to 60 km. An unbiased data set was obtained by correcting site errors, equalizing differences in sensor gain, eliminating directional biases in DF triggering, and keeping differences in signal attenuation over the two surfaces to a minimum. When a statistical analysis was performed on the frequency distributions of the signal amplitudes, there was no statistically significant difference in the peak amplitudes of first return strokes over land (lambda = 8.2 x 10(exp -3) mho/m) and over water (lambda = 4 mho/m). Therefore we infer that the conductivity of the underlying surface does not significantly affect the magnitude of the peak magnetic field, and hence the peak current, in the first return stroke of a cloud-to-ground lightning flash.
Incorporating human-water dynamics in a hyper-resolution land surface model
NASA Astrophysics Data System (ADS)
Vergopolan, N.; Chaney, N.; Wanders, N.; Sheffield, J.; Wood, E. F.
2017-12-01
The increasing demand for water, energy, and food is leading to unsustainable groundwater and surface water exploitation. As a result, the human interactions with the environment, through alteration of land and water resources dynamics, need to be reflected in hydrologic and land surface models (LSMs). Advancements in representing human-water dynamics still leave challenges related to the lack of water use data, water allocation algorithms, and modeling scales. This leads to an over-simplistic representation of human water use in large-scale models; this is in turn leads to an inability to capture extreme events signatures and to provide reliable information at stakeholder-level spatial scales. The emergence of hyper-resolution models allows one to address these challenges by simulating the hydrological processes and interactions with the human impacts at field scales. We integrated human-water dynamics into HydroBlocks - a hyper-resolution, field-scale resolving LSM. HydroBlocks explicitly solves the field-scale spatial heterogeneity of land surface processes through interacting hydrologic response units (HRUs); and its HRU-based model parallelization allows computationally efficient long-term simulations as well as ensemble predictions. The implemented human-water dynamics include groundwater and surface water abstraction to meet agricultural, domestic and industrial water demands. Furthermore, a supply-demand water allocation scheme based on relative costs helps to determine sectoral water use requirements and tradeoffs. A set of HydroBlocks simulations over the Midwest United States (daily, at 30-m spatial resolution for 30 years) are used to quantify the irrigation impacts on water availability. The model captures large reductions in total soil moisture and water table levels, as well as spatiotemporal changes in evapotranspiration and runoff peaks, with their intensity related to the adopted water management strategy. By incorporating human-water dynamics in a hyper-resolution LSM this work allows for progress on hydrological monitoring and predictions, as well as drought preparedness and water impact assessments at relevant decision-making scales.
Global Modeling, Field Campaigns, Upscaling and Ray Desjardins
NASA Technical Reports Server (NTRS)
Sellers, P. J.; Hall, F. G.
2012-01-01
In the early 1980's, it became apparent that land surface radiation and energy budgets were unrealistically represented in Global Circulation models (GCM's), Shortly thereafter, it became clear that the land carbon budget was also poorly represented in Earth System Models (ESM's), A number of scientific communities, including GCM/ESM modelers, micrometeorologists, satellite data specialists and plant physiologists, came together to design field experiments that could be used to develop and validate the contemporary prototype land surface models. These experiments were designed to measure land surface fluxes of radiation, heat, water vapor and CO2 using a network of flux towers and other plot-scale techniques, coincident with satellite measurements of related state variables, The interdisciplinary teams involved in these experiments quickly became aware of the scale gap between plot-scale measurements (approx 10 - 100m), satellite measurements (100m - 10 km), and GCM grid areas (l0 - 200km). At the time, there was no established flux measurement capability to bridge these scale gaps. Then, a Canadian science learn led by Ray Desjardins started to actively participate in the design and execution of the experiments, with airborne eddy correlation providing the radically innovative bridge across the scale gaps, In a succession of brilliantly executed field campaigns followed up by convincing scientific analyses, they demonstrated that airborne eddy correlation allied with satellite data was the most powerful upscaling tool available to the community, The rest is history: the realism and credibility of weather and climate models has been enormously improved enormously over the last 25 years with immense benefits to the public and policymakers.
NASA Cold Land Processes Experiment (CLPX 2002/03): Atmospheric analyses datasets
Glen E. Liston; Daniel L. Birkenheuer; Christopher A. Hiemstra; Donald W. Cline; Kelly Elder
2008-01-01
This paper describes the Local Analysis and Prediction System (LAPS) and the 20-km horizontal grid version of the Rapid Update Cycle (RUC20) atmospheric analyses datasets, which are available as part of the Cold Land Processes Field Experiment (CLPX) data archive. The LAPS dataset contains spatially and temporally continuous atmospheric and surface variables over...
Oguntunde, Philip G; van de Giesen, Nick
2004-11-01
The albedo (alpha) of vegetated land surfaces is a key regulatory factor in atmospheric circulation and plays an important role in mechanistic accounting of many ecological processes. This paper examines the influence of the phenological stages of maize (Zea mays) and cowpea (Vigna unguiculata) fields on observed albedo at a tropical site in Ghana. The crops were studied for the first and second planting dates in the year 2002. Crop management was similar for both seasons and measurements were taken from 10 mx10-m plots within crop fields. Four phenological stages were distinguished: (1) emergence, (2) vegetative, (3) flowering, and (4) maturity. alpha measured from two reference surfaces, short grass and bare soil, were used to study the change over the growing seasons. Surface alpha was measured and simulated at sun angles of 15, 30, 45, 60, and 75 degrees . Leaf area index (LAI) and crop height (CH) were also monitored. Generally, alpha increases from emergence to maturity for both planting dates in the maize field but slightly decreases after flowering in the cowpea field. For maize, the correlation coefficient ( R) between alpha and LAI equals 0.970, and the R between alpha and CH equals 0.969. Similarly, for cowpea these Rs are 0.988 and 0.943, respectively. A modified albedo model adequately predicted the observed alphas with an overall R>0.860. The relative difference in surface alpha with respect to the alpha values measured from the two reference surfaces is discussed. Data presented are expected to be a valuable input in agricultural water management, crop production models, eco-hydrological models and in the study of climate effects of agricultural production, and for the parameterization of land-surface schemes in regional weather and climate models.
Microwave Remote Sensing and the Cold Land Processes Field Experiment
NASA Technical Reports Server (NTRS)
Kim, Edward J.; Cline, Don; Davis, Bert; Hildebrand, Peter H. (Technical Monitor)
2001-01-01
The Cold Land Processes Field Experiment (CLPX) has been designed to advance our understanding of the terrestrial cryosphere. Developing a more complete understanding of fluxes, storage, and transformations of water and energy in cold land areas is a critical focus of the NASA Earth Science Enterprise Research Strategy, the NASA Global Water and Energy Cycle (GWEC) Initiative, the Global Energy and Water Cycle Experiment (GEWEX), and the GEWEX Americas Prediction Project (GAPP). The movement of water and energy through cold regions in turn plays a large role in ecological activity and biogeochemical cycles. Quantitative understanding of cold land processes over large areas will require synergistic advancements in 1) understanding how cold land processes, most comprehensively understood at local or hillslope scales, extend to larger scales, 2) improved representation of cold land processes in coupled and uncoupled land-surface models, and 3) a breakthrough in large-scale observation of hydrologic properties, including snow characteristics, soil moisture, the extent of frozen soils, and the transition between frozen and thawed soil conditions. The CLPX Plan has been developed through the efforts of over 60 interested scientists that have participated in the NASA Cold Land Processes Working Group (CLPWG). This group is charged with the task of assessing, planning and implementing the required background science, technology, and application infrastructure to support successful land surface hydrology remote sensing space missions. A major product of the experiment will be a comprehensive, legacy data set that will energize many aspects of cold land processes research. The CLPX will focus on developing the quantitative understanding, models, and measurements necessary to extend our local-scale understanding of water fluxes, storage, and transformations to regional and global scales. The experiment will particularly emphasize developing a strong synergism between process-oriented understanding, land surface models and microwave remote sensing. The experimental design is a multi-sensor, multi-scale (1-ha to 160,000 km ^ {2}) approach to providing the comprehensive data set necessary to address several experiment objectives. A description focusing on the microwave remote sensing components (ground, airborne, and spaceborne) of the experiment will be presented.
NASA Technical Reports Server (NTRS)
Santanello, Joseph A., Jr.; Peters-Lidard, Christa D.; Kumar, Sujay V.; Alonge, Charles; Tao, Wei-Kuo
2009-01-01
Land-atmosphere interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture states. The degree of coupling between the land surface and PBL in numerical weather prediction and climate models remains largely unexplored and undiagnosed due to the complex interactions and feedbacks present across a range of scales. Further, uncoupled systems or experiments (e.g., the Project for Intercomparison of Land Parameterization Schemes, PILPS) may lead to inaccurate water and energy cycle process understanding by neglecting feedback processes such as PBL-top entrainment. In this study, a framework for diagnosing local land-atmosphere coupling is presented using a coupled mesoscale model with a suite of PBL and land surface model (LSM) options along with observations during field experiments in the U. S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to the Land Information System (LIS), which provides a flexible and high-resolution representation and initialization of land surface physics and states. Within this framework, the coupling established by each pairing of the available PBL schemes in WRF with the LSMs in LIS is evaluated in terms of the diurnal temperature and humidity evolution in the mixed layer. The co-evolution of these variables and the convective PBL is sensitive to and, in fact, integrative of the dominant processes that govern the PBL budget, which are synthesized through the use of mixing diagrams. Results show how the sensitivity of land-atmosphere interactions to the specific choice of PBL scheme and LSM varies across surface moisture regimes and can be quantified and evaluated against observations. As such, this methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which will serve as a testbed for future experiments to evaluate coupling diagnostics within the community.
NASA Astrophysics Data System (ADS)
Peters-Lidard, C. D.; Kumar, S. V.; Santanello, J. A.; Tian, Y.; Rodell, M.; Mocko, D.; Reichle, R.
2008-12-01
The Land Information System (LIS; http://lis.gsfc.nasa.gov; Kumar et al., 2006; Peters-Lidard et al., 2007) is a flexible land surface modeling framework that has been developed with the goal of integrating satellite- and ground-based observational data products and advanced land surface modeling techniques to produce optimal fields of land surface states and fluxes. The LIS software was the co-winner of NASA's 2005 Software of the Year award. LIS facilitates the integration of observations from Earth-observing systems and predictions and forecasts from Earth System and Earth science models into the decision-making processes of partnering agency and national organizations. Due to its flexible software design, LIS can serve both as a Problem Solving Environment (PSE) for hydrologic research to enable accurate global water and energy cycle predictions, and as a Decision Support System (DSS) to generate useful information for application areas including disaster management, water resources management, agricultural management, numerical weather prediction, air quality and military mobility assessment. LIS has evolved from two earlier efforts - North American Land Data Assimilation System (NLDAS; Mitchell et al. 2004) and Global Land Data Assimilation System (GLDAS; Rodell et al. 2004) that focused primarily on improving numerical weather prediction skills by improving the characterization of the land surface conditions. Both of these systems, now use specific configurations of the LIS software in their current implementations. LIS not only consolidates the capabilities of these two systems, but also enables a much larger variety of configurations with respect to horizontal spatial resolution, input datasets and choice of land surface model through 'plugins'. In addition to these capabilities, LIS has also been demonstrated for parameter estimation (Peters-Lidard et al., 2008; Santanello et al., 2007) and data assimilation (Kumar et al., 2008). Examples and case studies demonstrating the capabilities and impacts of LIS for hydrometeorological modeling, land data assimilation and parameter estimation will be presented.
Climatological Downscaling and Evaluation of AGRMET Precipitation Analyses Over the Continental U.S.
NASA Astrophysics Data System (ADS)
Garcia, M.; Peters-Lidard, C. D.; Eylander, J. B.; Daly, C.; Tian, Y.; Zeng, J.
2007-05-01
The spatially distributed application of a land surface model (LSM) over a region of interest requires the application of similarly distributed precipitation fields that can be derived from various sources, including surface gauge networks, surface-based radar, and orbital platforms. The spatial variability of precipitation influences the spatial organization of soil temperature and moisture states and, consequently, the spatial variability of land- atmosphere fluxes. The accuracy of spatially-distributed precipitation fields can contribute significantly to the uncertainty of model-based hydrological states and fluxes at the land surface. Collaborations between the Air Force Weather Agency (AFWA), NASA, and Oregon State University have led to improvements in the processing of meteorological forcing inputs for the NASA-GSFC Land Information System (LIS; Kumar et al. 2006), a sophisticated framework for LSM operation and model coupling experiments. Efforts at AFWA toward the production of surface hydrometeorological products are currently in transition from the legacy Agricultural Meteorology modeling system (AGRMET) to use of the LIS framework and procedures. Recent enhancements to meteorological input processing for application to land surface models in LIS include the assimilation of climate-based information for the spatial interpolation and downscaling of precipitation fields. Climatological information included in the LIS-based downscaling procedure for North America is provided by a monthly high-resolution PRISM (Daly et al. 1994, 2002; Daly 2006) dataset based on a 30-year analysis period. The combination of these sources and methods attempts to address the strengths and weaknesses of available legacy products, objective interpolation methods, and the PRISM knowledge-based methodology. All of these efforts are oriented on an operational need for timely estimation of spatial precipitation fields at adequate spatial resolution for customer dissemination and near-real-time simulations in regions of interest. This work focuses on value added to the AGRMET precipitation product by the inclusion of high-quality climatological information on a monthly time scale. The AGRMET method uses microwave-based satellite precipitation estimates from various polar-orbiting platforms (NOAA POES and DMSP), infrared-based estimates from geostationary platforms (GOES, METEOSAT, etc.), related cloud analysis products, and surface gauge observations in a complex and hierarchical blending process. Results from processing of the legacy AGRMET precipitation products over the U.S. using LIS-based methods for downscaling, both with and without climatological factors, are evaluated against high-resolution monthly analyses using the PRISM knowledge- based method (Daly et al. 2002). It is demonstrated that the incorporation of climatological information in a downscaling procedure can significantly enhance the accuracy, and potential utility, of AFWA precipitation products for military and civilian customer applications.
Soil management and conservation: Irrigation: Methods
USDA-ARS?s Scientific Manuscript database
Irrigation applies water to soil to improve crop production. The three main methods of irrigation are surface, sprinkler and micro. Surface irrigation is used on 85% of the irrigated land in the world. It generally requires lower capital investment because the soil conveys water within the field, ra...
Apollo 12 crewmembers during geological field trip
1969-10-24
S69-55662 (10 Oct. 1969) --- Astronauts Alan L. Bean (left) and Charles Conrad Jr., the two crewmen of the Apollo 12 lunar landing mission who are scheduled to participate in two lengthy periods of extravehicular activity (EVA) on the lunar surface, are pictured during a geological field trip and training at a simulated lunar surface area near Flagstaff, Arizona. Here Conrad, the Apollo 12 commander, gets a close look through hand lens at the stratigraphy (study of strata or layers beneath the surface) of a man-dug hole, while Bean, the Apollo 12 mission's lunar module pilot, looks on. The topography in this area, with several man-made modifications, resembles very closely much of the topography found on the lunar surface. While Conrad and Bean explore the lunar surface (plans call for Apollo 12 spacecraft to land in the Sea of Storms), astronaut Richard F. Gordon Jr., command module pilot for the Apollo 12 mission, will remain with the Command and Service Modules (CSM) in lunar orbit. The Apollo 12 mission is scheduled to lift off from Cape Kennedy on Nov. 14, 1969.
NASA Astrophysics Data System (ADS)
Xiang, T.; Vivoni, E. R.; Gochis, D. J.; Mascaro, G.
2015-12-01
Heterogeneous land surface conditions are essential components of land-atmosphere interactions in regions of complex terrain and have the potential to affect convective precipitation formation. Yet, due to their high complexity, hydrologic processes over mountainous regions are not well understood, and are usually parameterized in simple ways within coupled land-atmosphere modeling frameworks. With the improving model physics and spatial resolution of numerical weather prediction models, there is an urgent need to understand how land surface processes affect local and regional meteorological processes. In the North American Monsoon (NAM) region, the summer rainy season is accompanied by a dramatic greening of mountain ecosystems that adds spatiotemporal variability in vegetation which is anticipated to impact the conditions leading to convection, mountain-valley circulations and mesoscale organization. In this study, we present results from a detailed analysis of a high-resolution (1 km) land surface model, Noah-MP, in a large, mountainous watershed of the NAM region - the Rio Sonora (21,264 km2) in Mexico. In addition to capturing the spatial variations in terrain and soil distributions, recently-developed features in Noah-MP allow the model to read time-varying vegetation parameters derived from remotely-sensed vegetation indices; however, this new implementation has not been fully evaluated. Therefore, we assess the simulated spatiotemporal fields of soil moisture, surface temperature and surface energy fluxes through comparisons to remote sensing products and results from coarser land surface models obtained from the North American Land Data Assimilation System. We focus attention on the impact of vegetation changes along different elevation bands on the diurnal cycle of surface energy fluxes to provide a baseline for future analyses of mountain-valley circulations using a coupled land-atmosphere modeling system. Our study also compares limited streamflow observations in the large watershed to simulations using the terrain and channel routing when Noah-MP is run within the WRF-Hydro modeling framework, with the goals of validating the rainfall-runoff partitioning and translating the spatiotemporal mountain processes into improvements in streamflow predictions.
Validation of Satellite Retrieved Land Surface Variables
NASA Technical Reports Server (NTRS)
Lakshmi, Venkataraman; Susskind, Joel
1999-01-01
The effective use of satellite observations of the land surface is limited by the lack of high spatial resolution ground data sets for validation of satellite products. Recent large scale field experiments include FIFE, HAPEX-Sahel and BOREAS which provide us with data sets that have large spatial coverage and long time coverage. It is the objective of this paper to characterize the difference between the satellite estimates and the ground observations. This study and others along similar lines will help us in utilization of satellite retrieved data in large scale modeling studies.
NASA Technical Reports Server (NTRS)
Smith, Eric A.; Nicholson, Sharon
1987-01-01
The status of the data sets is discussed. Progress was made in both data analysis and modeling areas. The atmospheric and land surface contributions to the net radiation budget over the Sahara-Sahel region is being decoupled. The interannual variability of these two processes was investigated and this variability related to seasonal rainfall fluctuations. A modified Barnes objective analysis scheme was developed which uses an eliptic scan pattern and a 3-pass iteration of the difference fields.
NASA Technical Reports Server (NTRS)
Kim, E.; Tedesco, M.; Reichle, R.; Choudhury, B.; Peters-Lidard C.; Foster, J.; Hall, D.; Riggs, G.
2006-01-01
Microwave-based retrievals of snow parameters from satellite observations have a long heritage and have so far been generated primarily by regression-based empirical "inversion" methods based on snapshots in time. Direct assimilation of microwave radiance into physical land surface models can be used to avoid errors associated with such retrieval/inversion methods, instead utilizing more straightforward forward models and temporal information. This approach has been used for years for atmospheric parameters by the operational weather forecasting community with great success. Recent developments in forward radiative transfer modeling, physical land surface modeling, and land data assimilation are converging to allow the assembly of an integrated framework for snow/cold lands modeling and radiance assimilation. The objective of the Goddard snow radiance assimilation project is to develop such a framework and explore its capabilities. The key elements of this framework include: a forward radiative transfer model (FRTM) for snow, a snowpack physical model, a land surface water/energy cycle model, and a data assimilation scheme. In fact, multiple models are available for each element enabling optimization to match the needs of a particular study. Together these form a modular and flexible framework for self-consistent, physically-based remote sensing and water/energy cycle studies. In this paper we will describe the elements and the integration plan. All modules will operate within the framework of the Land Information System (LIS), a land surface modeling framework with data assimilation capabilities running on a parallel-node computing cluster. Capabilities for assimilation of snow retrieval products are already under development for LIS. We will describe plans to add radiance-based assimilation capabilities. Plans for validation activities using field measurements will also be discussed.
Initialization of soil-water content in regional-scale atmospheric prediction models
NASA Technical Reports Server (NTRS)
Smith, Christopher B.; Lakhtakia, Mercedes; Capehart, William J.; Carlson, Toby N.
1994-01-01
The purpose of this study is to demonstrate the feasibility of determining the soil-water content fields required as initial conditions for land surface components within atmospheric prediction models. This is done using a model of the hydrologic balance and conventional meteorological observations, land cover, and soils information. A discussion is presented of the subgrid-scale effects, the integration time, and the choice of vegetation type on the soil-water content patterns. Finally, comparisons are made between two The Pennsylvania State University/National Center for Atmospheric Research mesoscale model simulations, one using climatological fields and the other one using the soil-moisture fields produced by this new method.
"Efficiency Space" - A Framework for Evaluating Joint Evaporation and Runoff Behavior
NASA Technical Reports Server (NTRS)
Koster, Randal
2014-01-01
At the land surface, higher soil moisture levels generally lead to both increased evaporation for a given amount of incoming radiation (increased evaporation efficiency) and increased runoff for a given amount of precipitation (increased runoff efficiency). Evaporation efficiency and runoff efficiency can thus be said to vary with each other, motivating the development of a unique hydroclimatic analysis framework. Using a simple water balance model fitted, in different experiments, with a wide variety of functional forms for evaporation and runoff efficiency, we transform net radiation and precipitation fields into fields of streamflow that can be directly evaluated against observations. The optimal combination of the functional forms the combination that produces the most skillful stream-flow simulations provides an indication for how evaporation and runoff efficiencies vary with each other in nature, a relationship that can be said to define the overall character of land surface hydrological processes, at least to first order. The inferred optimal relationship is represented herein as a curve in efficiency space and should be valuable for the evaluation and development of GCM-based land surface models, which by this measure are often found to be suboptimal.
Emission-dominated gas exchange of elemental mercury vapor over natural surfaces in China
NASA Astrophysics Data System (ADS)
Wang, Xun; Lin, Che-Jen; Yuan, Wei; Sommar, Jonas; Zhu, Wei; Feng, Xinbin
2016-09-01
Mercury (Hg) emission from natural surfaces plays an important role in global Hg cycling. The present estimate of global natural emission has large uncertainty and remains unverified against field data, particularly for terrestrial surfaces. In this study, a mechanistic model is developed for estimating the emission of elemental mercury vapor (Hg0) from natural surfaces in China. The development implements recent advancements in the understanding of air-soil and air-foliage exchange of Hg0 and redox chemistry in soil and on surfaces, incorporates the effects of soil characteristics and land use changes by agricultural activities, and is examined through a systematic set of sensitivity simulations. Using the model, the net exchange of Hg0 between the atmosphere and natural surfaces of mainland China is estimated to be 465.1 Mg yr-1, including 565.5 Mg yr-1 from soil surfaces, 9.0 Mg yr-1 from water bodies, and -100.4 Mg yr-1 from vegetation. The air-surface exchange is strongly dependent on the land use and meteorology, with 9 % of net emission from forest ecosystems; 50 % from shrubland, savanna, and grassland; 33 % from cropland; and 8 % from other land uses. Given the large agricultural land area in China, farming activities play an important role on the air-surface exchange over farmland. Particularly, rice field shift from a net sink (3.3 Mg uptake) during April-October (rice planting) to a net source when the farmland is not flooded (November-March). Summing up the emission from each land use, more than half of the total emission occurs in summer (51 %), followed by spring (28 %), autumn (13 %), and winter (8 %). Model verification is accomplished using observational data of air-soil/air-water fluxes and Hg deposition through litterfall for forest ecosystems in China and Monte Carlo simulations. In contrast to the earlier estimate by Shetty et al. (2008) that reported large emission from vegetative surfaces using an evapotranspiration approach, the estimate in this study shows natural emissions are primarily from grassland and dry cropland. Such an emission pattern may alter the current understanding of Hg emission outflow from China as reported by Lin et al. (2010b) because a substantial natural Hg emission occurs in West China.
Modification of Soil Temperature and Moisture Budgets by Snow Processes
NASA Astrophysics Data System (ADS)
Feng, X.; Houser, P.
2006-12-01
Snow cover significantly influences the land surface energy and surface moisture budgets. Snow thermally insulates the soil column from large and rapid temperature fluctuations, and snow melting provides an important source for surface runoff and soil moisture. Therefore, it is important to accurately understand and predict the energy and moisture exchange between surface and subsurface associated with snow accumulation and ablation. The objective of this study is to understand the impact of land surface model soil layering treatment on the realistic simulation of soil temperature and soil moisture. We seek to understand how many soil layers are required to fully take into account soil thermodynamic properties and hydrological process while also honoring efficient calculation and inexpensive computation? This work attempts to address this question using field measurements from the Cold Land Processes Field Experiment (CLPX). In addition, to gain a better understanding of surface heat and surface moisture transfer process between land surface and deep soil involved in snow processes, numerical simulations were performed at several Meso-Cell Study Areas (MSAs) of CLPX using the Center for Ocean-Land-Atmosphere (COLA) Simplified Version of the Simple Biosphere Model (SSiB). Measurements of soil temperature and soil moisture were analyzed at several CLPX sites with different vegetation and soil features. The monthly mean vertical profile of soil temperature during October 2002 to July 2003 at North Park Illinois River exhibits a large near surface variation (<5 cm), reveals a significant transition zone from 5 cm to 25 cm, and becomes uniform beyond 25cm. This result shows us that three soil layers are reasonable in solving the vertical variation of soil temperature at these study sites. With 6 soil layers, SSiB also captures the vertical variation of soil temperature during entire winter season, featuring with six soil layers, but the bare soil temperature is underestimated and root-zone soil temperature is overestimated during snow melting; which leads to overestimated temperature variations down to 20 cm. This is caused by extra heat loss from upper soil level and insufficient heat transport from the deep soil. Further work will need to verify if soil temperature displays similar vertical thermal structure for different vegetation and soil types during snow season. This study provides insight to the surface and subsurface thermodynamic and hydrological processes involved in snow modeling which is important for accurate snow simulation.
Detection of land degradation with polarimetric SAR
NASA Technical Reports Server (NTRS)
Ray, Terrill W.; Farr, Tom G.; Van Zyl, Jakob J.
1992-01-01
Multispectral radar polarimeter data were collected over the Manix Basin Area of the Mojave desert using an airborne SAR. An analysis of the data reveals unusual polarization responses which are attributed to the formation of wind ripples on the surfaces of fields that have been abandoned for more than 5 years. This hypothesis has been confirmed through field observations, and a second-order perturbation model is shown to effectively model the polarization responses. The results demonstrate the usefulness of remote sensing techniques for the study of land degradation at synoptic scales.
NASA Astrophysics Data System (ADS)
Zheng, Zhi-yuan; Wei, Zhi-gang; Wen, Zhi-ping; Dong, Wen-jie; Li, Zhen-chao; Wen, Xiao-hang; Zhu, Xian; Chen, Chen; Hu, Shan-shan
2018-02-01
Land surface emissivity is a significant variable in energy budgets, land cover assessments, and environment and climate studies. However, the assumption of an emissivity constant is being used in Gobi broadband emissivity (GbBE) parameterization scheme in numerical models because of limited knowledge surrounding the spatiotemporal variation characteristics of GbBE. To address this issue, we analyzed the variation characteristics of GbBE and possible impact factor-surface soil moisture based on long-term continuous and high temporal resolution field observational experiments over a typical Gobi underlying surface in arid and semiarid areas in northwestern China. The results indicate that GbBE has obvious daily and diurnal variation features, especially diurnal cycle characteristics. The multi-year average of the daily average of GbBE is in the range of 0.932 to 0.970 with an average of 0.951 ± 0.008, and the average diurnal GbBE is in the range of 0.880 to 0.940 with an average of 0.906 ± 0.018. GbBE varies with surface soil moisture content. We observed a slight decrease in GbBE with an increase in soil moisture, although this change was not very obvious because of the low soil moisture in this area. Nevertheless, we think that soil moisture must be one of the most significant impact factors on GbBE in arid and semiarid areas. Soil moisture must be taken into account into the parameterization schemes of bare soil broadband emissivity in land surface models. Additional field experiments and studies should be carried out in order to clarify this issue.
NASA Technical Reports Server (NTRS)
Matijevic, J. R.; Bickler, D. B.; Braun, D. F.; Eisen, H. J.; Matthies, L. H.; Mishkin, A. H.; Stone, H. W.; van Nieuwstadt, L. M.; Wen, L. C.; Wilcox, B. H.;
1996-01-01
An exciting scientific component of the Pathfinder mission is the rover, which will act as a mini-field geologist by providing us with access to samples for chemical analyses and close-up images of the Martian surface, performing active experiments to modify the surface and study the results, and exploring the landing site area.
USDA-ARS?s Scientific Manuscript database
Thermal infrared (TIR) remote sensing of land-surface temperature (LST) provides valuable information about the sub-surface moisture status required for estimating evapotranspiration (ET) and detecting the onset and severity of drought. While empirical indices measuring anomalies in LST and vegetati...
NASA Technical Reports Server (NTRS)
Golombek, M. P. (Editor); Edgett, K. S. (Editor); Rice, J. W., Jr. (Editor)
1995-01-01
This volume, the first of two comprising the technical report for this workshop, contains papers that have been accepted for presentation at the Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region, September 24-30, 1995, in Spokane, Washington. The Mars Pathfinder Project received a new start in October 1993 as one of the next missions in NASA's long-term Mars exploration program. The mission involves landing a single vehicle on the surface of Mars in 1997. The project is one of the first Discovery-class missions and is required to be a quick, low-cost mission and achieve a set of significant but focused engineering, science, and technology objectives. The primary objective is to demonstrate a low-cost cruise, entry, descent, and landing system required to place a payload on the martian surface in a safe, operational configuration. Additional objectives include the deployment and operation of various science instruments and a microrover. Pathfinder paves the way for a cost-effective implementation of future Mars lander missions. Also included in this volume is the field trip guide to the Channeled Scabland and Missoula Lake Break-out. On July 4, 1997, Mars Pathfinder is scheduled to land near 19.5 deg N, 32.8 deg W, in a portion of Ares Vallis. The landing ellipse covers a huge (100 x 200 km) area that appears to include both depositional and erosional landforms created by one or more giant, catastrophic floods. One of the best known terrestrial analogs to martian outflow channels (such as Ares Vallis) is the region known as the Channeled Scabland. The field trip guide describes some of the geomorphological features of the Channeled Scabland and adjacent Lake Missoula break-out area near Lake Pend Oreille, Idaho.
NASA Technical Reports Server (NTRS)
Carpenter, L. (Editor)
1980-01-01
Accomplishments and future plans are described for the following areas: (1) geology - geobotanical indicators and geopotential data; (2) modeling magnetic fields; (3) modeling the structure, composition, and evolution of the Earth's crust; (4) global and regional motions of the Earth's crust and earthquake occurrence; (5) modeling geopotential from satellite tracking data; (6) modeling the Earth's gravity field; (7) global Earth dynamics; (8) sea surface topography, ocean dynamics; and geophysical interpretation; (9) land cover and land use; (10) physical and remote sensing attributes important in detecting, measuring, and monitoring agricultural crops; (11) prelaunch studies using LANDSAT D; (12) the multispectral linear array; (13) the aircraft linear array pushbroom radiometer; and (14) the spaceborne laser ranging system.
Impact of land use changes on hydrology of Mt. Kilimanjaro. The case of Lake Jipe catchment
NASA Astrophysics Data System (ADS)
Ngugi, Keziah; Ogindo, Harun; Ertsen, Maurits
2015-04-01
Mt. Kilimanjaro is an important water tower in Kenya and Tanzania. Land degradation and land use changes have contributed to dwindling surface water resources around Mt. Kilimanjaro. This study focuses on Lake Jipe catchment of about 451Km2 (Ndetei 2011) which is mainly drained by River Lumi, a tributary of river Pangani. River Lumi starts from Mt. Kilimanjaro and flows North east wards to cross the border from Tanzania to Kenya eventually flowing into Lake Jipe which is a trans-boundary lake. The main purpose of this study was to investigate historical land use changes and relate this to reduction in surface water resources. The study will propose measures that could restore the catchment thereby enhancing surface water resources feeding Lake Jipe. A survey was conducted to document community perspectives of historical land use changes. This information was corroborated using Landsat remote sensed images spanning the period 1985-2013 to determine changes in the land cover due to human activities on Lake Jipe Catchment. River Lumi flow data was obtained from Water Resources Management Authority and analyzed for flow trends. The dwindling extent of the Lake was obtained from the community's perspective survey and by Landsat images. Community survey and remote sensing indicated clearing of the forest on the mountain and conversion of the same to crop production fields; damming of river Lumi in Tanzania, conversion of bush land to crop production fields further downstream of river Lumi and irrigation. There is heavy infestation of the invasive species Prosopis juliflora which had aggressively colonized grazing land and blocked irrigation canals. Other land use changes include land fragmentation due to subdivision. Insecure land tenure was blamed for failure by farmers to develop soil and water conservation infrastructure. Available River gauging data showed a general decline in river flow. Heavy flooding occurred during rainy seasons. Towards Lake Jipe after the river gauging station, several springs discharge into river Lumi and the river becomes permanent. The community believes Lake Jipe is a dying lake and will be gone in the coming years unless interventions to save it are implemented. Most of river Lumi water was delivered directly into the lakes outlet, river Ruvu, thus by-passing Lake Jipe. This was due to siltation that blocked river Lumis mouth. Consequently, lake Jipes volume and surface area have reduced dramatically from over the years. Drying of Lake Jipe will affect a lot of people who depend on the lake and the ecosystem. Addressing the problems requires re-afforestation measures and soil and moisture conservation. The severe runoff need to be dammed especially on the Kenyan side to create artificial surface water resources. River Lumi should be trained to discharge into the lake. Land tenure security need to be improved as incentives for proper land utilization. New farming methods to increase land productivity will encourage farmers to practice soil and water conservation measure.
NASA Astrophysics Data System (ADS)
Houborg, R.; McCabe, M. F.; Rosas Aguilar, J.; Anderson, M. C.; Hain, C.
2014-12-01
The Middle East and North Africa (MENA) region is an area characterized by limited fresh water resources, an often inefficient use of these, and relatively poor in-situ monitoring as a result of sparse meteorological observations. Enhanced satellite-based monitoring systems are needed for aiding local water resource and agricultural management activities in these data poor arid environments. A multi-sensor and multi-scale land-surface flux monitoring capacity is being implemented over parts of MENA in order to provide meaningful decision support at relevant spatiotemporal scales. The integrated modeling system uses the Atmosphere-Land Exchange Inverse (ALEXI) model and associated flux disaggregation scheme (DisALEXI), and the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) in conjunction with model reanalysis data and remotely sensed data from polar orbiting (Landsat and MODIS; MODerate resolution Imaging Spectroradiometer) and geostationary (MSG; Meteosat Second Generation) satellite platforms to facilitate daily estimates of land surface fluxes down to sub-field scale (i.e. 30 m). Within this modeling system, thermal infrared satellite data provide information about the sub-surface moisture status and plant stress, obviating the need for precipitation input and error-prone soil surface characterizations. In this study, the integrated ALEXI-DisALEXI-STARFM framework is applied over an irrigated agricultural region in Saudi Arabia, and the daily estimates of Landsat scale water, energy and carbon fluxes are evaluated against available flux tower observations and other independent in-situ and satellite-based records. The study addresses the challenges associated with time-continuous sub-field scale mapping of land-surface fluxes in a harsh desert environment, and looks into the optimization of model descriptions and parameterizations and meteorological forcing and vegetation inputs for application over these regions.
Assessment of environments for Mars Science Laboratory entry, descent, and surface operations
Vasavada, Ashwin R.; Chen, Allen; Barnes, Jeffrey R.; Burkhart, P. Daniel; Cantor, Bruce A.; Dwyer-Cianciolo, Alicia M.; Fergason, Robini L.; Hinson, David P.; Justh, Hilary L.; Kass, David M.; Lewis, Stephen R.; Mischna, Michael A.; Murphy, James R.; Rafkin, Scot C.R.; Tyler, Daniel; Withers, Paul G.
2012-01-01
The Mars Science Laboratory mission aims to land a car-sized rover on Mars' surface and operate it for at least one Mars year in order to assess whether its field area was ever capable of supporting microbial life. Here we describe the approach used to identify, characterize, and assess environmental risks to the landing and rover surface operations. Novel entry, descent, and landing approaches will be used to accurately deliver the 900-kg rover, including the ability to sense and "fly out" deviations from a best-estimate atmospheric state. A joint engineering and science team developed methods to estimate the range of potential atmospheric states at the time of arrival and to quantitatively assess the spacecraft's performance and risk given its particular sensitivities to atmospheric conditions. Numerical models are used to calculate the atmospheric parameters, with observations used to define model cases, tune model parameters, and validate results. This joint program has resulted in a spacecraft capable of accessing, with minimal risk, the four finalist sites chosen for their scientific merit. The capability to operate the landed rover over the latitude range of candidate landing sites, and for all seasons, was verified against an analysis of surface environmental conditions described here. These results, from orbital and model data sets, also drive engineering simulations of the rover's thermal state that are used to plan surface operations.
NASA Astrophysics Data System (ADS)
Rogge, Wolfgang F.; Medeiros, Patricia M.; Simoneit, Bernd R. T.
Fugitive dust from the erosion of arid and fallow land, after harvest and during agricultural activities, can at times be the dominant source of airborne particulate matter. In order to assess the source contributions to a given site, chemical mass balance (CMB) modeling is typically used together with source-specific profiles for organic and inorganic constituents. Yet, the mass balance closure can be achieved only if emission profiles for all major sources are considered. While a higher degree of mass balance closure has been achieved by adding individual organic marker compounds to elements, ions, EC, and organic carbon (OC), major source profiles for fugitive dust are not available. Consequently, neither the exposure of the population living near fugitive dust sources from farm land, nor its chemical composition is known. Surface soils from crop fields are enriched in plant detritus from both above and below ground plant parts; therefore, surface soil dust contains natural organic compounds from the crops and soil microbiota. Here, surface soils derived from fields growing cotton, safflower, tomato, almonds, and grapes have been analyzed for more than 180 organic compounds, including natural lipids, saccharides, pesticides, herbicides, and polycyclic aromatic hydrocarbon (PAH). The major result of this study is that selective biogenically derived organic compounds are suitable markers of fugitive dust from major agricultural crop fields in the San Joaquin Valley. Aliphatic homologs exhibit the typical biogenic signatures of epicuticular plant waxes and are therefore indicative of fugitive dust emissions and mechanical abrasion of wax protrusions from leaf surfaces. Saccharides, among which α- and β-glucose, sucrose, and mycose show the highest concentrations in surface soils, have been proposed to be generic markers for fugitive dust from cultivated land. Similarly, steroids are strongly indicative of fugitive dust. Yet, triterpenoids reveal the most pronounced distribution differences for all types of cultivated soils examined here and are by themselves powerful markers for fugitive dust that allow differentiation between the types of crops cultivated. PAHs are also found in some surface soils, as well as persistent pesticides, e.g., DDE, Fosfall, and others.
Chen, Cheng-long; Gao, Ming; Ni, Jiu-pai; Xie, De-ti; Deng, Hua
2016-05-15
As an independent water-collecting area, small catchment is the source of non-point source pollution in Three Gorges Region. Choosing 3 kinds of the most representative land-use types and using them to lay monitoring points of overland runoff within the small catchment of Wangjiagou in Fuling of Three Gorges Region, the author used the samples of surface runoff collected through the twelve natural rainfalls from May to December to analyze the feature of spatial-temporal change of Nitrogen's losses concentrations under the influence of different land use types and the hillslopes and small catchments composed by those land use types, revealing the relation between different land-use types and Nitrogen's losses of small catchments in Three Gorges Region. The result showed: the average losses concentration of TN showed the biggest difference for different land use types during the period of spring crops, and the average value of dry land was 1. 61 times and 6.73 times of the values of interplanting field of mulberry and paddy field, respectively; the change of the losses concentration of TN was most conspicuous in the 3 periods of paddy field. The main element was NO₃⁻-N, and the relation between TN and NO₃⁻-N showed a significant linear correlation. TN's and NO₃⁻-N's losses concentrations were significantly and positively correlated with the area ratio of corn and mustard, but got a significant negative correlation with the area ratio of paddy and mulberry; NH₄⁺-N's losses concentrations got a significant positive correlation with the area ratio of mustard. Among all the hillslopes composed by different land use types, TN's average losses concentration of surface runoff of the hillslope composed by interplantating field of mulberry and paddy land during the three periods was the lowest, and the values were 2.55, 11.52, 8.58 mg · L⁻¹, respectively; the hillslope of rotation plough land of corn and mustard had the maximum value, and the values were 27.51, 25.11, 27.11 mg · L⁻¹, respectively; different land use types and spatial combination ways of subcatchment had a greater influence on TN's losses concentrations, so using a reasonable way to adjust land use structure and spatial arrangement of whole catchment was an effective measure to control the source of non-point source pollution of Three Gorges Region.
2012-02-16
Snapshot from a simulation run on the Pleiades supercomputer. It depicts a fluctuating pressure field on aircraft nose landing gear and fuselage surfaces. The simulation helped scientists better understand the effects of landing gear and acoustic noise. The goal of the study was to improve the current understanding of aircraft nose landing gear noise, which will lead to quieter, more efficient airframe components for future aircraft designs. The visualization was produced with help from the NAS Data Analysis & Visualization group. Investigator: Mehdi Khorrami, NASA Langley Research Center.
PAVEMENTS, *REINFORCED PLASTICS), LANDING FIELDS, SPRAYS, GLASS TEXTILES, LAMINATED PLASTICS, TEST METHODS, FOUNDATIONS(STRUCTURES), SANDWICH CONSTRUCTION, SOILS, FEASIBILITY STUDIES, LOAD DISTRIBUTION
Evolving the Land Information System into a Cloud Computing Service
DOE Office of Scientific and Technical Information (OSTI.GOV)
Houser, Paul R.
The Land Information System (LIS) was developed to use advanced flexible land surface modeling and data assimilation frameworks to integrate extremely large satellite- and ground-based observations with advanced land surface models to produce continuous high-resolution fields of land surface states and fluxes. The resulting fields are extremely useful for drought and flood assessment, agricultural planning, disaster management, weather and climate forecasting, water resources assessment, and the like. We envisioned transforming the LIS modeling system into a scientific cloud computing-aware web and data service that would allow clients to easily setup and configure for use in addressing large water management issues.more » The focus of this Phase 1 project was to determine the scientific, technical, commercial merit and feasibility of the proposed LIS-cloud innovations that are currently barriers to broad LIS applicability. We (a) quantified the barriers to broad LIS utility and commercialization (high performance computing, big data, user interface, and licensing issues); (b) designed the proposed LIS-cloud web service, model-data interface, database services, and user interfaces; (c) constructed a prototype LIS user interface including abstractions for simulation control, visualization, and data interaction, (d) used the prototype to conduct a market analysis and survey to determine potential market size and competition, (e) identified LIS software licensing and copyright limitations and developed solutions, and (f) developed a business plan for development and marketing of the LIS-cloud innovation. While some significant feasibility issues were found in the LIS licensing, overall a high degree of LIS-cloud technical feasibility was found.« less
NASA Astrophysics Data System (ADS)
Williams, John L.; Maxwell, Reed M.; Monache, Luca Delle
2013-12-01
Wind power is rapidly gaining prominence as a major source of renewable energy. Harnessing this promising energy source is challenging because of the chaotic nature of wind and its inherently intermittent nature. Accurate forecasting tools are critical to support the integration of wind energy into power grids and to maximize its impact on renewable energy portfolios. We have adapted the Data Assimilation Research Testbed (DART), a community software facility which includes the ensemble Kalman filter (EnKF) algorithm, to expand our capability to use observational data to improve forecasts produced with a fully coupled hydrologic and atmospheric modeling system, the ParFlow (PF) hydrologic model and the Weather Research and Forecasting (WRF) mesoscale atmospheric model, coupled via mass and energy fluxes across the land surface, and resulting in the PF.WRF model. Numerous studies have shown that soil moisture distribution and land surface vegetative processes profoundly influence atmospheric boundary layer development and weather processes on local and regional scales. We have used the PF.WRF model to explore the connections between the land surface and the atmosphere in terms of land surface energy flux partitioning and coupled variable fields including hydraulic conductivity, soil moisture, and wind speed and demonstrated that reductions in uncertainty in these coupled fields realized through assimilation of soil moisture observations propagate through the hydrologic and atmospheric system. The sensitivities found in this study will enable further studies to optimize observation strategies to maximize the utility of the PF.WRF-DART forecasting system.
Advances in Land Data Assimilation at the NASA Goddard Space Flight Center
NASA Technical Reports Server (NTRS)
Reichle, Rolf
2009-01-01
Research in land surface data assimilation has grown rapidly over the last decade. In this presentation we provide a brief overview of key research contributions by the NASA Goddard Space Flight Center (GSFC). The GSFC contributions to land assimilation primarily include the continued development and application of the Land Information System (US) and the ensemble Kalman filter (EnKF). In particular, we have developed a method to generate perturbation fields that are correlated in space, time, and across variables and that permit the flexible modeling of errors in land surface models and observations, along with an adaptive filtering approach that estimates observation and model error input parameters. A percentile-based scaling method that addresses soil moisture biases in model and observational estimates opened the path to the successful application of land data assimilation to satellite retrievals of surface soil moisture. Assimilation of AMSR-E surface soil moisture retrievals into the NASA Catchment model provided superior surface and root zone assimilation products (when validated against in situ measurements and compared to the model estimates or satellite observations alone). The multi-model capabilities of US were used to investigate the role of subsurface physics in the assimilation of surface soil moisture observations. Results indicate that the potential of surface soil moisture assimilation to improve root zone information is higher when the surface to root zone coupling is stronger. Building on this experience, GSFC leads the development of the Level 4 Surface and Root-Zone Soil Moisture (L4_SM) product for the planned NASA Soil-Moisture-Active-Passive (SMAP) mission. A key milestone was the design and execution of an Observing System Simulation Experiment that quantified the contribution of soil moisture retrievals to land data assimilation products as a function of retrieval and land model skill and yielded an estimate of the error budget for the SMAP L4_SM product. Terrestrial water storage observations from GRACE satellite system were also successfully assimilated into the NASA Catchment model and provided improved estimates of groundwater variability when compared to the model estimates alone. Moreover, satellite-based land surface temperature (LST) observations from the ISCCP archive were assimilated using a bias estimation module that was specifically designed for LST assimilation. As with soil moisture, LST assimilation provides modest yet statistically significant improvements when compared to the model or satellite observations alone. To achieve the improvement, however, the LST assimilation algorithm must be adapted to the specific formulation of LST in the land model. An improved method for the assimilation of snow cover observations was also developed. Finally, the coupling of LIS to the mesoscale Weather Research and Forecasting (WRF) model enabled investigations into how the sensitivity of land-atmosphere interactions to the specific choice of planetary boundary layer scheme and land surface model varies across surface moisture regimes, and how it can be quantified and evaluated against observations. The on-going development and integration of land assimilation modules into the Land Information System will enable the use of GSFC software with a variety of land models and make it accessible to the research community.
The Autonomous Precision Landing and Hazard Detection and Avoidance Technology (ALHAT)
NASA Technical Reports Server (NTRS)
Epp, Chirold D.; Smith, Thomas B.
2007-01-01
As NASA plans to send humans back to the Moon and develop a lunar outpost, technologies must be developed to place humans and cargo safely, precisely, repeatedly, on the lunar surface with the capability to avoid surface hazards. Exploration Space Architecture Study requirements include the need for global lunar surface access with safe, precise landing without lighting constraints on terrain that may have landing hazards for human scale landing vehicles. Landing accuracies of perhaps 1,000 meters for sortie crew missions to 10 s of meters for Outpost class missions are required. The Autonomous precision Landing Hazard Avoidance Technology (ALHAT) project will develop the new and unique descent and landing Guidance, Navigation and Control (GNC) hardware and software technologies necessary for these capabilities. The ALHAT project will qualify a lunar descent and landing GNC system to a Technology Readiness Level (TRL) of 6 capable of supporting lunar crewed, cargo, and robotic missions. The (ALHAT) development project was chartered by NASA Headquarters in October 2006. The initial effort to write a project plan and define an ALHAT Team was followed by a fairly aggressive research and analysis effort to determine what technologies existed that could be developed and applied to the lunar landing problems indicated above. This paper describes the project development, research, analysis and concept evolution that has occurred since the assignment of the project. This includes the areas of systems engineering, GNC, sensors, sensor algorithms, simulations, fielding testing, laboratory testing, Hardware-In-The-Loop testing, system avionics and system certification concepts.
Development of Airport Surface Required Navigation Performance (RNP)
NASA Technical Reports Server (NTRS)
Cassell, Rick; Smith, Alex; Hicok, Dan
1999-01-01
The U.S. and international aviation communities have adopted the Required Navigation Performance (RNP) process for defining aircraft performance when operating the en-route, approach and landing phases of flight. RNP consists primarily of the following key parameters - accuracy, integrity, continuity, and availability. The processes and analytical techniques employed to define en-route, approach and landing RNP have been applied in the development of RNP for the airport surface. To validate the proposed RNP requirements several methods were used. Operational and flight demonstration data were analyzed for conformance with proposed requirements, as were several aircraft flight simulation studies. The pilot failure risk component was analyzed through several hypothetical scenarios. Additional simulator studies are recommended to better quantify crew reactions to failures as well as additional simulator and field testing to validate achieved accuracy performance, This research was performed in support of the NASA Low Visibility Landing and Surface Operations Programs.
Zhang, Geli; Xiao, Xiangming; Dong, Jinwei; Kou, Weili; Jin, Cui; Qin, Yuanwei; Zhou, Yuting; Wang, Jie; Menarguez, Michael Angelo; Biradar, Chandrashekhar
2016-01-01
Knowledge of the area and spatial distribution of paddy rice is important for assessment of food security, management of water resources, and estimation of greenhouse gas (methane) emissions. Paddy rice agriculture has expanded rapidly in northeastern China in the last decade, but there are no updated maps of paddy rice fields in the region. Existing algorithms for identifying paddy rice fields are based on the unique physical features of paddy rice during the flooding and transplanting phases and use vegetation indices that are sensitive to the dynamics of the canopy and surface water content. However, the flooding phenomena in high latitude area could also be from spring snowmelt flooding. We used land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to determine the temporal window of flooding and rice transplantation over a year to improve the existing phenology-based approach. Other land cover types (e.g., evergreen vegetation, permanent water bodies, and sparse vegetation) with potential influences on paddy rice identification were removed (masked out) due to their different temporal profiles. The accuracy assessment using high-resolution images showed that the resultant MODIS-derived paddy rice map of northeastern China in 2010 had a high accuracy (producer and user accuracies of 92% and 96%, respectively). The MODIS-based map also had a comparable accuracy to the 2010 Landsat-based National Land Cover Dataset (NLCD) of China in terms of both area and spatial pattern. This study demonstrated that our improved algorithm by using both thermal and optical MODIS data, provides a robust, simple and automated approach to identify and map paddy rice fields in temperate and cold temperate zones, the northern frontier of rice planting. PMID:27667901
Zhang, Geli; Xiao, Xiangming; Dong, Jinwei; Kou, Weili; Jin, Cui; Qin, Yuanwei; Zhou, Yuting; Wang, Jie; Menarguez, Michael Angelo; Biradar, Chandrashekhar
2015-08-01
Knowledge of the area and spatial distribution of paddy rice is important for assessment of food security, management of water resources, and estimation of greenhouse gas (methane) emissions. Paddy rice agriculture has expanded rapidly in northeastern China in the last decade, but there are no updated maps of paddy rice fields in the region. Existing algorithms for identifying paddy rice fields are based on the unique physical features of paddy rice during the flooding and transplanting phases and use vegetation indices that are sensitive to the dynamics of the canopy and surface water content. However, the flooding phenomena in high latitude area could also be from spring snowmelt flooding. We used land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to determine the temporal window of flooding and rice transplantation over a year to improve the existing phenology-based approach. Other land cover types (e.g., evergreen vegetation, permanent water bodies, and sparse vegetation) with potential influences on paddy rice identification were removed (masked out) due to their different temporal profiles. The accuracy assessment using high-resolution images showed that the resultant MODIS-derived paddy rice map of northeastern China in 2010 had a high accuracy (producer and user accuracies of 92% and 96%, respectively). The MODIS-based map also had a comparable accuracy to the 2010 Landsat-based National Land Cover Dataset (NLCD) of China in terms of both area and spatial pattern. This study demonstrated that our improved algorithm by using both thermal and optical MODIS data, provides a robust, simple and automated approach to identify and map paddy rice fields in temperate and cold temperate zones, the northern frontier of rice planting.
NASA Astrophysics Data System (ADS)
Senay, G. B.; Schauer, M.; Singh, R. K.; Friedrichs, M.
2017-12-01
Field-scale water use maps derived from evapotranspiration (ET) can characterize water use patterns and the impacts of water management decisions. This project generated historical (1984-2015) Landsat-based ET maps for the entire Upper Rio Grande basin which makes this one of the largest regions in the United States with remotely sensed historical ET at Landsat resolution. More than 10,000 Landsat images spanning 32 years were processed using the Operational Simplified Surface Energy Balance (SSEBop) model which integrates weather data and remotely sensed images to estimate monthly and annual ET. Time-series analysis focused on three water-intensive study areas within the basin: the San Luis Valley in Colorado, irrigated fields along the Rio Grande River near Albuquerque, NM, and irrigated fields near Las Cruces, NM. Preliminary analysis suggests land use changes result in declining water use in irrigated areas of the basin which corresponds with increases in land surface temperatures. Time-series analysis of water use patterns at multiple temporal and spatial scales demonstrates the impact of water management decisions on the availability of water in the basin. Comparisons with cropland data from the USDA (NASS CDL) demonstrate how water use for particular crop types changes over time in response to land use changes and shifts in water management. This study illustrates a useful application of "Big Data" earth observation science for quantifying impacts of climate and land use changes on water availability within the United States as well as applications in planning water resource allocation, managing water rights, and sustaining agricultural production in the Upper Rio Grande basin.
NASA Astrophysics Data System (ADS)
Caliskan, S.; de Beurs, K.
2010-12-01
Direct human impacts on the land surface are especially pronounced in agricultural regions that cover a substantial portion of the global land surface: 12% of the terrestrial surface is under active agricultural management. Crops display phenologies distinct from natural vegetation; the growing seasons are often shifted in time, crop establishment is generally fast and the vegetation is rapidly removed at harvest. Previously we have demonstrated that agricultural land abandonment alters land surface phenology sufficiently to be detectable from a time series of coarse resolution imagery. With land surface phenology models based on accumulated growing degree-days (AGDD) and AVHRR NDVI, we demonstrated that abandoned croplands covered with native grasses and weeds typically greened-up and peaked sooner than active croplands. Here we present an expansion of these analyses for the MODIS time period with the ultimate goal to map agricultural abandonment and expansion in European Russia from 2000 to 2010. We used the 8-day, 1km L3 Land Surface Temperature data (MOD11A2) to generate the accumulated growing degree days and the 16-day L3 Nadir BRDF-Adjusted reflectance data at 500m resolution (MCD43A4) to calculate NDVI. We calculated phenological metrics based on three methods: 1) Double-logistic models such as those applied to produce the standard MODIS phenology product (MOD12Q2); 2) A combination of NDII and NDVI; this method has been shown to provide start/end of season measurement closest to field observations in snowy areas; and 3) A quadratic model linking accumulated growing degree days and vegetation indices which we successfully applied in agricultural areas of Kazakhstan and semi-arid Africa. We selected Landsat imagery for two vastly different regions in Russia and present a Landsat-guided probabilistic detection of abandoned and active croplands for all available years of the MODIS image time series (2000-2010). For each region, we selected at least two images during the growing season and calculated the following indices: Normalized Difference Vegetation Index (NDVI), Tasseled Cap indices (Brightness, Greenness, Wetness), as well as the first three principal components for each image. We used the selected images to distinguish between the basic classes of agriculture, water, forest and urban areas, with the primary goal to separate between agricultural and non-agricultural regions. We compared class membership with ancillary regional agricultural statistics and targeted field observations collected in the summer of 2010. In the last part, we linked the Landsat based agricultural estimates and the MODIS phenological measurements using logistic regression and compared the agricultural maps with globally available land cover classifications.
Crustal evolution inferred from Apollo magnetic measurements
NASA Technical Reports Server (NTRS)
Dyal, P.; Daily, W. D.; Vanyan, L. L.
1978-01-01
Magnetic field and solar wind plasma density measurements were analyzed to determine the scale size characteristics of remanent fields at the Apollo 12, 15, and 16 landing sites. Theoretical model calculations of the field-plasma interaction, involving diffusion of the remanent field into the solar plasma, were compared to the data. The information provided by all these experiments shows that remanent fields over most of the lunar surface are characterized by spatial variations as small as a few kilometers. Large regions (50 to 100 km) of the lunar crust were probably uniformly magnetized during early crustal evolution. Bombardment and subsequent gardening of the upper layers of these magnetized regions left randomly oriented, smaller scale (5 to 10 km) magnetic sources close to the surface. The larger scale size fields of magnitude approximately 0.1 gammas are measured by the orbiting subsatellite experiments and the small scale sized remanent fields of magnitude approximately 100 gammas are measured by the surface experiments.
[Physicochemical properties of Guanting Reservoir sediment and its land application].
Su, De-Chun; Hu, Yu-Feng; Song, Chong-Wei; Wu, Fei-Long; Liu, Pei-Bin
2007-06-01
Surface sediment of Guanting Reservoir was dredged up and dewatered in field, and pollutant and physicochemical characterizations were mensurated. The stabilization and agricultural land use of the sediment was also studied in the field. Results showed that the sediments have a higher clay content, bulk density (1.89 g x cm(-3)) and lower porosity (23.8%), higher deoxidize material and available nitrogen, phosphorus concentration. Heavy metal and organochlorinated pesticides concentration was lower than the class II of national standard for soil. Stabilized the sediment with sand soil and straw could improve the physical property and decrease the concentration of deoxidize material and available nitrogen, phosphorus. Stabilized sediment could be a suitable medium for alfalfa, tree and corn growth and used for agricultural land.
Monitoring the Global Soil Moisture Climatology Using GLDAS/LIS
NASA Astrophysics Data System (ADS)
Meng, J.; Mitchell, K.; Wei, H.; Gottschalck, J.
2006-05-01
Soil moisture plays a crucial role in the terrestrial water cycle through governing the process of partitioning precipitation among infiltration, runoff and evaporation. Accurate assessment of soil moisture and other land states, namely, soil temperature, snowpack, and vegetation, is critical in numerical environmental prediction systems because of their regulation of surface water and energy fluxes between the surface and atmosphere over a variety of spatial and temporal scales. The Global Land Data Assimilation System (GLDAS) is developed, jointly by NASA Goddard Space Flight Center (GSFC) and NOAA National Centers for Environmental Prediction (NCEP), to perform high-quality global land surface simulation using state-of-art land surface models and further minimizing the errors of simulation by constraining the models with observation- based precipitation, and satellite land data assimilation techniques. The GLDAS-based Land Information System (LIS) infrastructure has been installed on the NCEP supercomputer that serves the operational weather and climate prediction systems. In this experiment, the Noah land surface model is offline executed within the GLDAS/LIS infrastructure, driven by the NCEP Global Reanalysis-2 (GR2) and the CPC Merged Analysis of Precipitation (CMAP). We use the same Noah code that is coupled to the operational NCEP Global Forecast System (GFS) for weather prediction and test bed versions of the NCEP Climate Forecast System (CFS) for seasonal prediction. For assessment, it is crucial that this uncoupled GLDAS/Noah uses exactly the same Noah code (and soil and vegetation parameters therein), and executes with the same horizontal grid, landmask, terrain field, soil and vegetation types, seasonal cycle of green vegetation fraction and surface albedo as in the coupled GFS/Noah and CFS/Noah. This execution is for the 25-year period of 1980-2005, starting with a pre-execution 10-year spin-up. This 25-year GLDAS/Noah global land climatology will be used for both climate variability assessment and as a source of land initial conditions for ensemble CFS/Noah seasonal hindcast experiments. Finally, this GLDAS/Noah climatology will serve as the foundation for a global drought/flood monitoring system that includes near realtime daily updates of the global land states.
2014-11-03
Bob Richards, co-founder and chief executive officer of Moon Express Inc., of Moffett Field, California, speaks to the media during an event to announce the company's selection to use Kennedy Space Center's facilities as part of NASA's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative. The event took place at Kennedy's automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST.
2014-11-03
CAPE CANAVERAL, Fla. - Tom Engler, deputy director of Center Planning and Development at NASA's Kennedy Space Center in Florida, speaks to members of the media during an event to announce the agency's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative and introduced one of the partners, Moon Express Inc. of Moffett Field, California. The event took place at Kennedy's automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST. Photo credit: NASA/Ben Smegelsky
2014-11-03
CAPE CANAVERAL, Fla. - Greg C. Shavers, Lander Technology director at Marshall Space Flight Center in Alabama, speaks to members of the media during an event to announce the agency's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative and introduced one of the partners, Moon Express Inc. of Moffett Field, California. The event took place at Kennedy's automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST. Photo credit: NASA/Ben Smegelsky
2014-11-03
CAPE CANAVERAL, Fla. - Bob Richards, co-founder and chief executive officer of Moon Express Inc., of Moffett Field, California, speaks to the media during an event to announce the company's selection to use Kennedy Space Center's facilities as part of NASA's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative. The event took place at Kennedy's automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST. Photo credit: NASA/Ben Smegelsky
2014-11-03
Greg C. Shavers, Lander Technology director at Marshall Space Flight Center in Alabama, speaks to members of the media during an event to announce the agency's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative and introduced one of the partners, Moon Express Inc. of Moffett Field, California. The event took place at Kennedy's automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST.
2014-11-03
Tom Engler, deputy director of Center Planning and Development at NASA's Kennedy Space Center in Florida, speaks to members of the media during an event to announce the agency's Lunar Cargo Transportation and Landing by Soft Touchdown, or Lunar CATALYST, initiative and introduced one of the partners, Moon Express Inc. of Moffett Field, California. The event took place at Kennedy's automated landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility. Moon Express is developing a lander with capabilities that will enable delivery of payloads to the surface of the moon, as well as new science and exploration missions of interest to NASA and scientific and academic communities. Moon Express will base its activities at Kennedy and utilize the Morpheus ALHAT field and a hangar nearby for CATALYST testing. The Advanced Exploration Systems Division of NASA's Human Exploration and Operations Mission Directorate manages Lunar CATALYST.
AmeriFlux US-KUT KUOM Turfgrass Field
McFadden, Joe [University of California, Santa Barbara
2016-01-01
This is the AmeriFlux version of the carbon flux data for the site US-KUT KUOM Turfgrass Field. Site Description - The site was a low-maintenace lawn consisting of cool-season turfgrasses, typical of residential lawns or urban parks in the study area. It was mowed to a height of 70 mm approximately once per week with clippings left to decompose on the surface, was not irrigated, and received one application of inorganic N fertilizer per year. The surrounding suburban residential neighborhood experienced rapid residential development in the 1950s; prior to that time, farms and nurseries were the predominant land-use types. Note that the land management of the field site changed (removal of the turfgrass lawn and planting of trees) AFTER the flux study was completed--this means that imagery after 2009 does not show the land conditions during the flux study.
Dynamic temperature fields under Mars landing sites and implications for supporting microbial life.
Ulrich, Richard; Kral, Tim; Chevrier, Vincent; Pilgrim, Robert; Roe, Larry
2010-01-01
While average temperatures on Mars may be too low to support terrestrial life-forms or aqueous liquids, diurnal peak temperatures over most of the planet can be high enough to provide for both, down to a few centimeters beneath the surface for some fraction of the time. A thermal model was applied to the Viking 1, Viking 2, Pathfinder, Spirit, and Opportunity landing sites to demonstrate the dynamic temperature fields under the surface at these well-characterized locations. A benchmark temperature of 253 K was used as a lower limit for possible metabolic activity, which corresponds to the minimum found for specific terrestrial microorganisms. Aqueous solutions of salts known to exist on Mars can provide liquid solutions well below this temperature. Thermal modeling has shown that 253 K is reached beneath the surface at diurnal peak heating for at least some parts of the year at each of these landing sites. Within 40 degrees of the equator, 253 K beneath the surface should occur for at least some fraction of the year; and, within 20 degrees , it will be seen for most of the year. However, any life-form that requires this temperature to thrive must also endure daily excursions to far colder temperatures as well as periods of the year where 253 K is never reached at all.
NASA Technical Reports Server (NTRS)
Golovin, Y. M.; Moshkin, B. Y.; Ekonomov, A. P. E.
1979-01-01
The characteristics of the field of radiation in the near surface layer of the atmosphere and on the surface of Venus are reported. Optical measurements made during the landing of the descent vehicles are described. The relief of the surface and the amount of dust on it are examined. The spectral relationship of the albedo of the soil and the light flux incident on the surface is discussed.
Flow-Field Investigation of Gear-Flap Interaction on a Gulfstream Aircraft Model
NASA Technical Reports Server (NTRS)
Yao, Chung-Sheng; Jenkins, Luther N.; Bartram, Scott M.; Harris, Jerome; Khorrami, Mehdi R.; Mace, W. Derry
2014-01-01
Off-surface flow measurements of a high-fidelity 18% scale Gulfstream aircraft model in landing configuration with the main landing gear deployed are presented. Particle Image Velocimetry (PIV) and Laser Velocimetry (LV) were used to measure instantaneous velocities in the immediate vicinity of the main landing gear and its wake and near the inboard tip of the flap. These measurements were made during the third entry of a series of tests conducted in the NASA Langley Research Center (LaRC) 14- by 22-Foot Subsonic Tunnel (14 x 22) to obtain a comprehensive set of aeroacoustic measurements consisting of both aerodynamic and acoustic data. The majority of the off-body measurements were obtained at a freestream Mach number of 0.2, angle of attack of 3 degrees, and flap deflection angle of 39 degrees with the landing gear on. A limited amount of data was acquired with the landing gear off. LV was used to measure the velocity field in two planes upstream of the landing gear and to measure two velocity profiles in the landing gear wake. Stereo and 2-D PIV were used to measure the velocity field over a region extending from upstream of the landing gear to downstream of the flap trailing edge. Using a special traverse system installed under the tunnel floor, the velocity field was measured at 92 locations to obtain a comprehensive picture of the pertinent flow features and characteristics. The results clearly show distinct structures in the wake that can be associated with specific components on the landing gear and give insight into how the wake is entrained by the vortex at the inboard tip of the flap.
USDA-ARS?s Scientific Manuscript database
While the land-application of animal manure provides many benefits, concerns exist regarding the subsequent transport of hormones and potential effects on aquatic ecosystems. This study compares two methods of dairy manure application, surface broadcasting and shallow disk injection, on the fate and...
Nonlocal Sediment Transport on Steep Lateral Moraines, Eastern Sierra Nevada, California, USA
NASA Astrophysics Data System (ADS)
Doane, Tyler H.; Furbish, David Jon; Roering, Joshua J.; Schumer, Rina; Morgan, Daniel J.
2018-01-01
Recent work has highlighted the significance of long-distance particle motions in hillslope sediment transport. Such motions imply that the flux at a given hillslope position is appropriately described as a weighted function of surrounding conditions that influence motions reaching the given position. Although the idea of nonlocal sediment transport is well grounded in theory, limited field evidence has been provided. We test local and nonlocal formulations of the flux and compare their ability to reproduce land surface profiles of steep moraines in California. We show that nonlocal and nonlinear models better reproduce evolved land surface profiles, notably the amount of lowering and concavity near the moraine crest and the lengthening and straightening of the depositional apron. The analysis provides the first estimates of key parameters that set sediment entrainment rates and travel distances in nonlocal formulations and highlights the importance of correctly specifying the entrainment rate when modeling land surface evolution. Moraine evolution associated with nonlocal and nonlinear transport formulations, when described in terms of the evolution of the Fourier transform of the moraine surface, displays a distinct behavior involving growth of certain wave numbers, in contrast to the decay of all wave numbers associated with linear transport. Nonlinear and nonlocal formulations share key mathematical elements yielding a nonlinear relation between the flux and the land surface slope.
Photosynthesis sensitivity to climate change in land surface models
NASA Astrophysics Data System (ADS)
Manrique-Sunen, Andrea; Black, Emily; Verhoef, Anne; Balsamo, Gianpaolo
2016-04-01
Accurate representation of vegetation processes within land surface models is key to reproducing surface carbon, water and energy fluxes. Photosynthesis determines the amount of CO2 fixated by plants as well as the water lost in transpiration through the stomata. Photosynthesis is calculated in land surface models using empirical equations based on plant physiological research. It is assumed that CO2 assimilation is either CO2 -limited, radiation -limited ; and in some models export-limited (the speed at which the products of photosynthesis are used by the plant) . Increased levels of atmospheric CO2 concentration tend to enhance photosynthetic activity, but the effectiveness of this fertilization effect is regulated by environmental conditions and the limiting factor in the photosynthesis reaction. The photosynthesis schemes at the 'leaf level' used by land surface models JULES and CTESSEL have been evaluated against field photosynthesis observations. Also, the response of photosynthesis to radiation, atmospheric CO2 and temperature has been analysed for each model, as this is key to understanding the vegetation response that climate models using these schemes are able to reproduce. Particular emphasis is put on the limiting factor as conditions vary. It is found that while at present day CO2 concentrations export-limitation is only relevant at low temperatures, as CO2 levels rise it becomes an increasingly important restriction on photosynthesis.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sellers, P.J.; Collatz, J.; Koster, R.
1996-09-01
A comprehensive series of global datasets for land-atmosphere models has been collected, formatted to a common grid, and released on a set of CD-ROMs. This paper describes the motivation for and the contents of the dataset. In June of 1992, an interdisciplinary earth science workshop was convened in Columbia, Maryland, to assess progress in land-atmosphere research, specifically in the areas of models, satellite data algorithms, and field experiments. At the workshop, representatives of the land-atmosphere modeling community defined a need for global datasets to prescribe boundary conditions, initialize state variables, and provide near-surface meteorological and radiative forcings for their models.more » The International Satellite Land Surface Climatology Project (ISLSCP), a part of the Global Energy and Water Cycle Experiment, worked with the Distributed Active Archive Center of the National Aeronautics and Space Administration Goddard Space Flight Center to bring the required datasets together in a usable format. The data have since been released on a collection of CD-ROMs. The datasets on the CD-ROMs are grouped under the following headings: vegetation; hydrology and soils; snow, ice, and oceans; radiation and clouds; and near-surface meteorology. All datasets cover the period 1987-88, and all but a few are spatially continuous over the earth`s land surface. All have been mapped to a common 1{degree} x 1{degree} equal-angle grid. The temporal frequency for most of the datasets is monthly. A few of the near-surface meteorological parameters are available both as six-hourly values and as monthly means. 26 refs., 8 figs., 2 tabs.« less
The Aggregate Representation of Terrestrial Land Covers Within Global Climate Models (GCM)
NASA Technical Reports Server (NTRS)
Shuttleworth, W. James; Sorooshian, Soroosh
1996-01-01
This project had four initial objectives: (1) to create a realistic coupled surface-atmosphere model to investigate the aggregate description of heterogeneous surfaces; (2) to develop a simple heuristic model of surface-atmosphere interactions; (3) using the above models, to test aggregation rules for a variety of realistic cover and meteorological conditions; and (4) to reconcile biosphere-atmosphere transfer scheme (BATS) land covers with those that can be recognized from space; Our progress in meeting these objectives can be summarized as follows. Objective 1: The first objective was achieved in the first year of the project by coupling the Biosphere-Atmosphere Transfer Scheme (BATS) with a proven two-dimensional model of the atmospheric boundary layer. The resulting model, BATS-ABL, is described in detail in a Masters thesis and reported in a paper in the Journal of Hydrology Objective 2: The potential value of the heuristic model was re-evaluated early in the project and a decision was made to focus subsequent research around modeling studies with the BATS-ABL model. The value of using such coupled surface-atmosphere models in this research area was further confirmed by the success of the Tucson Aggregation Workshop. Objective 3: There was excellent progress in using the BATS-ABL model to test aggregation rules for a variety of realistic covers. The foci of attention have been the site of the First International Satellite Land Surface Climatology Project Field Experiment (FIFE) in Kansas and one of the study sites of the Anglo-Brazilian Amazonian Climate Observational Study (ABRACOS) near the city of Manaus, Amazonas, Brazil. These two sites were selected because of the ready availability of relevant field data to validate and initiate the BATS-ABL model. The results of these tests are given in a Masters thesis, and reported in two papers. Objective 4: Progress far exceeded original expectations not only in reconciling BATS land covers with those that can be recognized from space, but also in then applying remotely-sensed land cover data to map aggregate values of BATS parameters for heterogeneous covers and interpreting these parameters in terms of surface-atmosphere exchanges.
The sensitivity of numerically simulated climates to land-surface boundary conditions
NASA Technical Reports Server (NTRS)
Mintz, Y.
1982-01-01
Eleven sensitivity experiments that were made with general circulation models to see how land-surface boundary conditions can influence the rainfall, temperature, and motion fields of the atmosphere are discussed. In one group of experiments, different soil moistures or albedos are prescribed as time-invariant boundary conditions. In a second group, different soil moistures or different albedos are initially prescribed, and the soil moisture (but not the albedo) is allowed to change with time according to the governing equations for soil moisture. In a third group, the results of constant versus time-dependent soil moistures are compared.
Phenocams bridge the gap between field and satellite observations in an arid grassland ecosystem
USDA-ARS?s Scientific Manuscript database
Near surface (i.e., camera) and satellite remote sensing metrics have become widely used indicators of plant growing seasons. While robust linkages have been established between field metrics and ecosystem exchange in many land cover types, assessment of how well remotely-derived season start and en...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tillman, Jack B.
In March 2008, Sandia National Laboratories (Sandia), in partnership with the Bureau of Land Management, Roswell Field Office, completed its responsibilities to plug and abandon wells and restore the surface conditions for the Sulimar Queens Unit, a 2,500 acre oil field, in Chaves County, Southeast New Mexico. Sandia assumed this liability in an agreement to obtain property to create a field laboratory to perform extensive testing and experimentation on enhanced oil recovery techniques for shallow oil fields. In addition to plugging and abandoning 28 wells, the project included the removal of surface structures and surface reclamation of disturbed lands associatedmore » with all plugged and abandoned wells, access roads, and other auxiliary facilities within unit boundaries. A contracting strategy was implemented to mitigate risk and reduce cost. As the unit is an important wildlife habitat for prairie chickens, sand dune lizards, and mule deer, the criteria for the restoration and construction process were designed to protect and enhance the wildlife habitat. Lessons learned from this project include: (1) extreme caution should be exercised when entering agreements that include future liabilities, (2) partnering with the regulator has huge benefits, and (3) working with industry experts, who were familiar with the work, and subcontractors, who provided the network to complete the project cost effectively.« less
Assessing land leveling needs and performance with unmanned aerial system
NASA Astrophysics Data System (ADS)
Enciso, Juan; Jung, Jinha; Chang, Anjin; Chavez, Jose Carlos; Yeom, Junho; Landivar, Juan; Cavazos, Gabriel
2018-01-01
Land leveling is the initial step for increasing irrigation efficiencies in surface irrigation systems. The objective of this paper was to evaluate potential utilization of an unmanned aerial system (UAS) equipped with a digital camera to map ground elevations of a grower's field and compare them with field measurements. A secondary objective was to use UAS data to obtain a digital terrain model before and after land leveling. UAS data were used to generate orthomosaic images and three-dimensional (3-D) point cloud data by applying the structure for motion algorithm to the images. Ground control points (GCPs) were established around the study area, and they were surveyed using a survey grade dual-frequency GPS unit for accurate georeferencing of the geospatial data products. A digital surface model (DSM) was then generated from the 3-D point cloud data before and after laser leveling to determine the topography before and after the leveling. The UAS-derived DSM was compared with terrain elevation measurements acquired from land surveying equipment for validation. Although 0.3% error or root mean square error of 0.11 m was observed between UAS derived and ground measured ground elevation data, the results indicated that UAS could be an efficient method for determining terrain elevation with an acceptable accuracy when there are no plants on the ground, and it can be used to assess the performance of a land leveling project.
Investigation of aircraft landing in variable wind fields
NASA Technical Reports Server (NTRS)
Frost, W.; Reddy, K. R.
1978-01-01
A digital simulation study is reported of the effects of gusts and wind shear on the approach and landing of aircraft. The gusts and wind shear are primarily those associated with wind fields created by surface wind passing around bluff geometries characteristic of buildings. Also, flight through a simple model of a thunderstorm is investigated. A two-dimensional model of aircraft motion was represented by a set of nonlinear equations which accounted for both spatial and temporal variations of winds. The landings of aircraft with the characteristics of a DC-8 and a DHC-6 were digitally simulated under different wind conditions with fixed and automatic controls. The resulting deviations in touchdown points and the controls that are required to maintain the desired flight path are presented. The presence of large bluff objects, such as buildings in the flight path is shown to have considerable effect on aircraft landings.
76 FR 35967 - Amendment of Class E Airspace; Bozeman, MT
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-21
..., Gallatin Field Airport, Bozeman, MT, to accommodate aircraft using Instrument Landing System (ILS... 6005 Class E airspace areas extending upward from 700 feet or more above the surface of the earth...
NASA Technical Reports Server (NTRS)
Case, Jonathan L.; LaCasse, Katherine M.; Santanello, Joseph A., Jr.; Lapenta, William M.; Petars-Lidard, Christa D.
2007-01-01
The exchange of energy and moisture between the Earth's surface and the atmospheric boundary layer plays a critical role in many hydrometeorological processes. Accurate and high-resolution representations of surface properties such as sea-surface temperature (SST), vegetation, soil temperature and moisture content, and ground fluxes are necessary to better understand the Earth-atmosphere interactions and improve numerical predictions of weather and climate phenomena. The NASA/NWS Short-term Prediction Research and Transition (SPORT) Center is currently investigating the potential benefits of assimilating high-resolution datasets derived from the NASA moderate resolution imaging spectroradiometer (MODIS) instruments using the Weather Research and Forecasting (WRF) model and the Goddard Space Flight Center Land Information System (LIS). The LIS is a software framework that integrates satellite and ground-based observational and modeled data along with multiple land surface models (LSMs) and advanced computing tools to accurately characterize land surface states and fluxes. The LIS can be run uncoupled to provide a high-resolution land surface initial condition, and can also be run in a coupled mode with WRF to integrate surface and soil quantities using any of the LSMs available in LIS. The LIS also includes the ability to optimize the initialization of surface and soil variables by tuning the spin-up time period and atmospheric forcing parameters, which cannot be done in the standard WRF. Among the datasets available from MODIS, a leaf-area index field and composite SST analysis are used to improve the lower boundary and initial conditions to the LIS/WRF coupled model over both land and water. Experiments will be conducted to measure the potential benefits from using the coupled LIS/WRF model over the Florida peninsula during May 2004. This month experienced relatively benign weather conditions, which will allow the experiments to focus on the local and mesoscale impacts of the high-resolution MODIS datasets and optimized soil and surface initial conditions. Follow-on experiments will examine the utility of such an optimized WRF configuration for more complex weather scenarios such as convective initiation. This paper will provide an overview of the experiment design and present preliminary results from selected cases in May 2004.
Estimation of Transpiration and Water Use Efficiency Using Satellite and Field Observations
NASA Technical Reports Server (NTRS)
Choudhury, Bhaskar J.; Quick, B. E.
2003-01-01
Structure and function of terrestrial plant communities bring about intimate relations between water, energy, and carbon exchange between land surface and atmosphere. Total evaporation, which is the sum of transpiration, soil evaporation and evaporation of intercepted water, couples water and energy balance equations. The rate of transpiration, which is the major fraction of total evaporation over most of the terrestrial land surface, is linked to the rate of carbon accumulation because functioning of stomata is optimized by both of these processes. Thus, quantifying the spatial and temporal variations of the transpiration efficiency (which is defined as the ratio of the rate of carbon accumulation and transpiration), and water use efficiency (defined as the ratio of the rate of carbon accumulation and total evaporation), and evaluation of modeling results against observations, are of significant importance in developing a better understanding of land surface processes. An approach has been developed for quantifying spatial and temporal variations of transpiration, and water-use efficiency based on biophysical process-based models, satellite and field observations. Calculations have been done using concurrent meteorological data derived from satellite observations and four dimensional data assimilation for four consecutive years (1987-1990) over an agricultural area in the Northern Great Plains of the US, and compared with field observations within and outside the study area. The paper provides substantive new information about interannual variation, particularly the effect of drought, on the efficiency values at a regional scale.
Scanning Electron Microscopy with Samples in an Electric Field
Frank, Ludĕk; Hovorka, Miloš; Mikmeková, Šárka; Mikmeková, Eliška; Müllerová, Ilona; Pokorná, Zuzana
2012-01-01
The high negative bias of a sample in a scanning electron microscope constitutes the “cathode lens” with a strong electric field just above the sample surface. This mode offers a convenient tool for controlling the landing energy of electrons down to units or even fractions of electronvolts with only slight readjustments of the column. Moreover, the field accelerates and collimates the signal electrons to earthed detectors above and below the sample, thereby assuring high collection efficiency and high amplification of the image signal. One important feature is the ability to acquire the complete emission of the backscattered electrons, including those emitted at high angles with respect to the surface normal. The cathode lens aberrations are proportional to the landing energy of electrons so the spot size becomes nearly constant throughout the full energy scale. At low energies and with their complete angular distribution acquired, the backscattered electron images offer enhanced information about crystalline and electronic structures thanks to contrast mechanisms that are otherwise unavailable. Examples from various areas of materials science are presented.
NASA Astrophysics Data System (ADS)
Kim, Hye-Won; Yeom, Jong-Min; Shin, Daegeun; Choi, Sungwon; Han, Kyung-Soo; Roujean, Jean-Louis
2017-08-01
In this study, a new assessment of thin cloud detection with the application of bidirectional reflectance distribution function (BRDF) model-based background surface reflectance was undertaken by interpreting surface spectra characterized using the Geostationary Ocean Color Imager (GOCI) over a land surface area. Unlike cloud detection over the ocean, the detection of cloud over land surfaces is difficult due to the complicated surface scattering characteristics, which vary among land surface types. Furthermore, in the case of thin clouds, in which the surface and cloud radiation are mixed, it is difficult to detect the clouds in both land and atmospheric fields. Therefore, to interpret background surface reflectance, especially underneath cloud, the semiempirical BRDF model was used to simulate surface reflectance by reflecting solar angle-dependent geostationary sensor geometry. For quantitative validation, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data were used to make a comparison with the proposed cloud masking result. As a result, the new cloud masking scheme resulted in a high probability of detection (POD = 0.82) compared with the Moderate Resolution Imaging Spectroradiometer (MODIS) (POD = 0.808) for all cloud cases. In particular, the agreement between the CALIPSO cloud product and new GOCI cloud mask was over 94% when detecting thin cloud (e.g., altostratus and cirrus) from January 2014 to June 2015. This result is relatively high in comparison with the result from the MODIS Collection 6 cloud mask product (MYD35).
Towards a Near Real-Time Satellite-Based Flux Monitoring System for the MENA Region
NASA Astrophysics Data System (ADS)
Ershadi, A.; Houborg, R.; McCabe, M. F.; Anderson, M. C.; Hain, C.
2013-12-01
Satellite remote sensing has the potential to offer spatially and temporally distributed information on land surface characteristics, which may be used as inputs and constraints for estimating land surface fluxes of carbon, water and energy. Enhanced satellite-based monitoring systems for aiding local water resource assessments and agricultural management activities are particularly needed for the Middle East and North Africa (MENA) region. The MENA region is an area characterized by limited fresh water resources, an often inefficient use of these, and relatively poor in-situ monitoring as a result of sparse meteorological observations. To address these issues, an integrated modeling approach for near real-time monitoring of land surface states and fluxes at fine spatio-temporal scales over the MENA region is presented. This approach is based on synergistic application of multiple sensors and wavebands in the visible to shortwave infrared and thermal infrared (TIR) domain. The multi-scale flux mapping and monitoring system uses the Atmosphere-Land Exchange Inverse (ALEXI) model and associated flux disaggregation scheme (DisALEXI), and the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) in conjunction with model reanalysis data and multi-sensor remotely sensed data from polar orbiting (e.g. Landsat and MODerate resolution Imaging Spectroradiometer (MODIS)) and geostationary (MSG; Meteosat Second Generation) satellite platforms to facilitate time-continuous (i.e. daily) estimates of field-scale water, energy and carbon fluxes. Within this modeling system, TIR satellite data provide information about the sub-surface moisture status and plant stress, obviating the need for precipitation input and a detailed soil surface characterization (i.e. for prognostic modeling of soil transport processes). The STARFM fusion methodology blends aspects of high frequency (spatially coarse) and spatially fine resolution sensors and is applied directly to flux output fields to facilitate daily mapping of fluxes at sub-field scales. A complete processing infrastructure to automatically ingest and pre-process all required input data and to execute the integrated modeling system for near real-time agricultural monitoring purposes over targeted MENA sites is being developed, and initial results from this concerted effort will be discussed.
NASA Technical Reports Server (NTRS)
Steyaert, Louis T.; Knox, Robert G.
2007-01-01
The local environment where we live within the Earth's biosphere is often taken for granted. This environment can vary depending on whether the land cover is a forest, grassland, wetland, water body, bare soil, pastureland, agricultural field, village, residential suburb, or an urban complex with concrete, asphalt, and large buildings. In general, the type and characteristics of land cover influence surface temperatures, sunlight exposure and duration, relative humidity, wind speed and direction, soil moisture amount, plant life, birds, and other wildlife in our backyards. The physical and biological properties (biophysical characteristics) of land cover help to determine our surface environment because they directly affect surface radiation, heat, and soil moisture processes, and also feedback to regional weather and climate. Depending on the spatial scale and land use intensity, land cover changes can have profound impacts on our local and regional environment. Over the past 350 years, the eastern half of the United States, an area extending from the grassland prairies of the Great Plains to the Gulf and Atlantic coasts, has experienced extensive land cover and land use changes that began with land clearing in the 1600s, led to extensive deforestation and intensive land use practices by 1920, and then evolved to the present-day landscape. Determining the consequences of such land cover changes on regional and global climate is a major research issue. Such research requires detailed historical land cover data and modeling experiments simulating historical climates. Given the need to understand the effects of historical land cover changes in the eastern United States, some questions include: - What were the most important land cover transformations and how did they alter biophysical characteristics of the land cover at key points in time since the mid-1600s? - How have land cover and land use changes over the past 350 years affected the land surface environment including surface weather, hydrologic, and climatic variability? - How do the potential effects of regional human-induced land cover change on the environment compare to similar changes that are caused by the natural variations of the Earth's climate system? To help answer these questions, we reconstructed a fractional land cover and biophysical parameter dataset for the eastern United States at 1650, 1850, 1920, and 1992 time-slices. Each land cover fraction is associated with a biophysical parameter class, a suite of parameters defining the biophysical characteristics of that kind of land cover. This new dataset is designed for use in computer models of land-atmosphere interactions, to understand and quantify the effects of historical land cover changes on the water, energy, and carbon cycles
NASA Technical Reports Server (NTRS)
Bosilovich, Michael G.; Suarez, Max J. (Editor); Schubert, Siegfried D.
1998-01-01
First ISLSCP Field Experiment (FIFE) observations have been used to validate the near-surface proper- ties of various versions of the Goddard Earth Observing System (GEOS) Data Assimilation System. The site- averaged FIFE data set extends from May 1987 through November 1989, allowing the investigation of several time scales, including the annual cycle, daily means and diurnal cycles. Furthermore, the development of the daytime convective planetary boundary layer is presented for several days. Monthly variations of the surface energy budget during the summer of 1988 demonstrate the affect of the prescribed surface soil wetness boundary conditions. GEOS data comes from the first frozen version of the assimilation system (GEOS-1 DAS) and two experimental versions of GEOS (v. 2.0 and 2.1) with substantially greater vertical resolution and other changes that influence the boundary layer. This report provides a baseline for future versions of the GEOS data assimilation system that will incorporate a state-of-the-art land surface parameterization. Several suggestions are proposed to improve the generality of future comparisons. These include the use of more diverse field experiment observations and an estimate of gridpoint heterogeneity from the new land surface parameterization.
Physically Accurate Soil Freeze-Thaw Processes in a Global Land Surface Scheme
NASA Astrophysics Data System (ADS)
Cuntz, Matthias; Haverd, Vanessa
2018-01-01
The model Soil-Litter-Iso (SLI) calculates coupled heat and water transport in soil. It was recently implemented into the Australian land surface model CABLE, which is the land component of the Australian Community Climate and Earth System Simulator (ACCESS). Here we extended SLI to include accurate freeze-thaw processes in the soil and snow. SLI provides thence an implicit solution of the energy and water balances of soil and snow as a standalone model and within CABLE. The enhanced SLI was tested extensively against theoretical formulations, laboratory experiments, field data, and satellite retrievals. The model performed well for all experiments at wide-ranging temporal and spatial scales. SLI melts snow faster at the end of the cold season compared to observations though because there is no subgrid variability within SLI given by the implicit, coupled solution of energy and water. Combined CABLE-SLI shows very realistic dynamics and extent of permafrost on the Northern hemisphere. It illustrated, however, also the limits of possible comparisons between large-scale land surface models and local permafrost observations. CABLE-SLI exhibits the same patterns of snow depth and snow water equivalent on the Northern hemisphere compared to satellite-derived observations but quantitative comparisons depend largely on the given meteorological input fields. Further extension of CABLE-SLI with depth-dependence of soil carbon will allow realistic projections of the development of permafrost and frozen carbon stocks in a changing climate.
MEaSUREs Land Surface Temperature from GOES Satellites
NASA Astrophysics Data System (ADS)
Pinker, Rachel T.; Chen, Wen; Ma, Yingtao; Islam, Tanvir; Borbas, Eva; Hain, Chris; Hulley, Glynn; Hook, Simon
2017-04-01
Information on Land Surface Temperature (LST) can be generated from observations made from satellites in low Earth orbit (LEO) such as MODIS and ASTER and by sensors in geostationary Earth orbit (GEO) such as GOES. Under a project titled: "A Unified and Coherent Land Surface Temperature and Emissivity Earth System Data Record for Earth Science" led by Jet Propulsion Laboratory, an effort is underway to develop long term consistent information from both such systems. In this presentation we will describe an effort to derive LST information from GOES satellites. Results will be presented from two approaches: 1) based on regression developed from a wide range of simulations using MODTRAN, SeeBor Version 5.0 global atmospheric profiles and the CAMEL (Combined ASTER and MODIS Emissivity for Land) product based on the standard University of Wisconsin 5 km emissivity values (UWIREMIS) and the ASTER Global Emissivity Database (GED) product; 2) RTTOV radiative transfer model driven with MERRA-2 reanalysis fields. We will present results of evaluation of these two methods against various products, such as MOD11, and ground observations for the five year period of (2004-2008).
NASA Technical Reports Server (NTRS)
Frazee, C. J.; Westin, F. C.; Gropper, J.; Myers, V. I.
1972-01-01
Research to determine the optimum time or season for obtaining imagery to identify and map soil limitations was conducted in the proposed Oahe irrigation project area in South Dakota. The optimum time for securing photographs or imagery is when the soil surface patterns are most apparent. For cultivated areas similar to the study area, May is the optimum time. The fields are cultivated or the planted crop has not yet masked soil surface features. Soil limitations in 59 percent of the field of the flight line could be mapped using the above criteria. The remaining fields cannot be mapped because the vegetation or growing crops do not express features related to soil differences. This suggests that imagery from more than one year is necessary to map completely the soil limitations of Oahe area by remote sensing techniques. Imagery from the other times studied is not suitable for identifying and mapping soil limitations of Oahe area by remote sensing techniques. Imagery from the other times studied is not suitable for identifying and mapping soil limitations because the vegetative cover masked the soil surface and does not reflect soil differences.
Restoring the biological crust cover of soils across biomes in arid North America
NASA Astrophysics Data System (ADS)
Garcia-Pichel, Ferran; Antoninka, Anita; Bowker, Matthew; Giraldo Silva, Ana; Nelson, Corey; Velasco Ayuso, Sergio; Barger, Nichole; Belnap, Jayne; Reed, Sasha; Duniway, Michael
2015-04-01
Biological soil crust communities provide important ecosystem services to arid lands, particularly regarding soil fertility and stability against erosion. In North America, and in many other areas of the globe, increasingly intense human activities, ranging from cattle grazing to military training, have resulted in the significant deterioration of biological soil surface cover of soils. With the intent of attaining sustainable land use practices, we are conducting a 5-year, multi-institutional research effort to develop feasible soil crusts restoration strategies for US military lands. We are including field sites of varying climatic regions (warm and cold deserts, in the Chihuahuan Desert and in the Great Basin, respectively) and varying edaphic characteristics (sandy and silty soils in each). We have multiple aims. First, we aim to establishing effective "biocrust nurseries" that produce viable and pedigreed inoculum, as a supply center for biocrust restoration and for research and development. Second, we aim to develop optimal field application methods of biocrust inoculum in a series of field trials. Currently in our second year of research, we will be reporting on significant advances made on optimizing methodologies for the large-scale supply of inoculum based on a) pedigreed laboratory cultures that match the microbial community structure of the original sites, and b) "in soil" biomass enhancement, whereby small amounts of local crusts are nursed under greenhouse conditions to yield hundred-fold increases in biomass without altering significantly community structure. We will also report on field trials for methodologies in field application, which included shading, watering, application of chemical polymers, and soil surface roughening. In a soon-to-be-initiated effort we also aim to evaluate soil and plant responses to biocrust restoration with respect to plant community structure, soil fertility, and soil stability, in multi-factorial field experiments. An important part of the plan will be to construct effective channels for sharing challenges and solutions in biocrust restoration with military and federal land managers.
Investigation of remote sensing to detect near-surface groundwater on irrigated lands
NASA Technical Reports Server (NTRS)
Ryland, D. W.; Schmer, F. A.; Moore, D. G.
1975-01-01
The application of remote sensing techniques was studied for detecting areas with high water tables in irrigated agricultural lands. Aerial data were collected by the LANDSAT-1 satellite and aircraft over the Kansas/Bostwick Irrigation District in Republic and Jewell Counties, Kansas. LANDSAT-1 data for May 12 and August 10, 1973, and aircraft flights (midday and predawn) on August 10 and 11, 1973, and June 25 and 26, 1974, were obtained. Surface and water table contour maps and active observation well hydrographs were obtained from the Bureau of Reclamation for use in the analysis. Results of the study reveal that LANDSAT-1 data (May MSS band 6 and August MSS band 7) correlate significantly (0.01 level) with water table depth for 144 active observation wells located throughout the Kansas/Bostwick Irrigation District. However, a map of water table depths of less than 1.83 meters prepared from the LANDSAT-1 data did not compare favorably with a map of seeped lands of less than 1.22 m (4 feet) to the water table. Field evaluation of the map is necessary for a complete analysis. Analysis of three fields on a within or single-field basis for the 1973 LANDSAT-1 data also showed significant correlation results.
NASA Astrophysics Data System (ADS)
Wetzel, Peter J.; Boone, Aaron
1995-07-01
This paper presents a general description of, and demonstrates the capabilities of, the Parameterization for Land-Atmosphere-Cloud Exchange (PLACE). The PLACE model is a detailed process model of the partly cloudy atmospheric boundary layer and underlying heterogeneous land surfaces. In its development, particular attention has been given to three of the model's subprocesses: the prediction of boundary layer cloud amount, the treatment of surface and soil subgrid heterogeneity, and the liquid water budget. The model includes a three-parameter nonprecipitating cumulus model that feeds back to the surface and boundary layer through radiative effects. Surface heterogeneity in the PLACE model is treated both statistically and by resolving explicit subgrid patches. The model maintains a vertical column of liquid water that is divided into seven reservoirs, from the surface interception store down to bedrock.Five single-day demonstration cases are presented, in which the PLACE model was initialized, run, and compared to field observations from four diverse sites. The model is shown to predict cloud amount well in these while predicting the surface fluxes with similar accuracy. A slight tendency to underpredict boundary layer depth is noted in all cases.Sensitivity tests were also run using anemometer-level forcing provided by the Project for Inter-comparison of Land-surface Parameterization Schemes (PILPS). The purpose is to demonstrate the relative impact of heterogeneity of surface parameters on the predicted annual mean surface fluxes. Significant sensitivity to subgrid variability of certain parameters is demonstrated, particularly to parameters related to soil moisture. A major result is that the PLACE-computed impact of total (homogeneous) deforestation of a rain forest is comparable in magnitude to the effect of imposing heterogeneity of certain surface variables, and is similarly comparable to the overall variance among the other PILPS participant models. Were this result to be bourne out by further analysis, it would suggest that today's average land surface parameterization has little credibility when applied to discriminating the local impacts of any plausible future climate change.
Temporal and spatial changes of land use and landscape in a coal mining area in Xilingol grassland
NASA Astrophysics Data System (ADS)
Guan, Chunzhu; Zhang, Baolin; Li, Jiannan; Zhao, Junling
2017-01-01
Coal mining, particularly surface mining, inevitably disturbs land. According to Landsat images acquired over Xilingol grassland in 2005, 2009 and 2015, land uses were divided into seven classes, i. e., open stope, stripping area, waste-dump area, mine industrial area, farmland, urban area and the original landscape (grassland), using supervised classification and human-computer interactive interpretation. The overall classification accuracies were 97.72 %, 98.43 % and 96.73 %, respectively; the Kappa coefficients were 0.95, 0.97 and 0.95, respectively. Analysis on LUCC (Land Use and Cover Change) showed that surface coal mining disturbed grassland ecosystem: grassland decreased by 8661.15 hm2 in 2005-2015. The area and proportion of mining operation areas (open stope, stripping area, waste-dump area, mine industrial field) increased, but those of grassland decreased continuously. Transfer matrix of land use changes showed that waste-dump had the largest impacts in mining disturbance, and that effective reclamation of waste-dump areas would mitigate eco-environment destruction, as would be of great significance to protect fragile grassland eco-system. Six landscape index showed that landscape fragmentation increased, and the influences of human activity on landscape was mainly reflected in the expansion of mining area and urban area. Remote sensing monitoring of coal surface mining in grassland would accurately demonstrate the dynamics and trend of LUCC, providing scientific supports for ecological reconstruction in surface mining area.
NASA Astrophysics Data System (ADS)
Turner, Andrew; Bhat, Gs; Evans, Jonathan; Marsham, John; Martin, Gill; Parker, Douglas; Taylor, Chris; Bhattacharya, Bimal; Madan, Ranju; Mitra, Ashis; Mrudula, Gm; Muddu, Sekhar; Pattnaik, Sandeep; Rajagopal, En; Tripathi, Sachida
2015-04-01
The monsoon supplies the majority of water in South Asia, making understanding and predicting its rainfall vital for the growing population and economy. However, modelling and forecasting the monsoon from days to the season ahead is limited by large model errors that develop quickly, with significant inter-model differences pointing to errors in physical parametrizations such as convection, the boundary layer and land surface. These errors persist into climate projections and many of these errors persist even when increasing resolution. At the same time, a lack of detailed observations is preventing a more thorough understanding of monsoon circulation and its interaction with the land surface: a process governed by the boundary layer and convective cloud dynamics. The INCOMPASS project will support and develop modelling capability in Indo-UK monsoon research, including test development of a new Met Office Unified Model 100m-resolution domain over India. The first UK detachment of the FAAM research aircraft to India, in combination with an intensive ground-based observation campaign, will gather new observations of the surface, boundary layer structure and atmospheric profiles to go with detailed information on the timing of monsoon rainfall. Observations will be focused on transects in the northern plains of India (covering a range of surface types from irrigated to rain-fed agriculture, and wet to dry climatic zones) and across the Western Ghats and rain shadow in southern India (including transitions from land to ocean and across orography). A pilot observational campaign is planned for summer 2015, with the main field campaign to take place during spring/summer 2016. This project will advance our ability to forecast the monsoon, through a programme of measurements and modelling that aims to capture the key surface-atmosphere feedback processes in models. The observational analysis will allow a unique and unprecedented characterization of monsoon processes that will feed directly into model development at the UK Met Office and Indian NCMRWF, through model evaluation at a range of scales and leading to model improvement by working directly with parametrization developers. The project will institute a new long-term series of measurements of land surface fluxes, a particularly unconstrained observation for India, through eddy covariance flux towers. Combined with detailed land surface modelling using the Joint UK Land Environment Simulator (JULES) model, this will allow testing of land surface initialization in monsoon forecasts and improved land-atmosphere coupling.
30 CFR 901.20 - Approval of Alabama abandoned mine land reclamation plan.
Code of Federal Regulations, 2010 CFR
2010-07-01
..., 649 Monroe Street, Montgomery, AL 36131. (b) Office of Surface Mining Reclamation and Enforcement, Birmingham Field Office, Barber Business Park, 135 Gemini Circle, Homewood, AL 35209. [64 FR 20166, Apr. 26...
30 CFR 901.20 - Approval of Alabama abandoned mine land reclamation plan.
Code of Federal Regulations, 2014 CFR
2014-07-01
..., 649 Monroe Street, Montgomery, AL 36131. (b) Office of Surface Mining Reclamation and Enforcement, Birmingham Field Office, Barber Business Park, 135 Gemini Circle, Homewood, AL 35209. [64 FR 20166, Apr. 26...
30 CFR 901.20 - Approval of Alabama abandoned mine land reclamation plan.
Code of Federal Regulations, 2011 CFR
2011-07-01
..., 649 Monroe Street, Montgomery, AL 36131. (b) Office of Surface Mining Reclamation and Enforcement, Birmingham Field Office, Barber Business Park, 135 Gemini Circle, Homewood, AL 35209. [64 FR 20166, Apr. 26...
30 CFR 901.20 - Approval of Alabama abandoned mine land reclamation plan.
Code of Federal Regulations, 2012 CFR
2012-07-01
..., 649 Monroe Street, Montgomery, AL 36131. (b) Office of Surface Mining Reclamation and Enforcement, Birmingham Field Office, Barber Business Park, 135 Gemini Circle, Homewood, AL 35209. [64 FR 20166, Apr. 26...
30 CFR 901.20 - Approval of Alabama abandoned mine land reclamation plan.
Code of Federal Regulations, 2013 CFR
2013-07-01
..., 649 Monroe Street, Montgomery, AL 36131. (b) Office of Surface Mining Reclamation and Enforcement, Birmingham Field Office, Barber Business Park, 135 Gemini Circle, Homewood, AL 35209. [64 FR 20166, Apr. 26...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Delfanti, Lavinia; Colantoni, Andrea, E-mail: colantoni@unitus.it; Recanatesi, Fabio
Photovoltaic plants developed on rural land are becoming a common infrastructure in the Mediterranean region and may contribute, at least indirectly, to various forms of environmental degradation including landscape deterioration, land take, soil degradation and loss in traditional cropland and biodiversity. Our study illustrates a procedure estimating (i) the extension of ground-mounted photovoltaic fields at the municipal scale in Italy and (ii) inferring the socioeconomic profile of the Italian municipalities experiencing different expansion rates of ground-mounted photovoltaic fields over the last years (2007-2014). The procedure was based on diachronic information derived from official data sources integrated into a geographical decisionmore » support system. Our results indicate that the surface area of ground-mounted photovoltaic fields into rural land grew continuously in Italy between 2007 and 2014 with positive and increasing growth rates observed during 2007-2011 and positive but slightly decreasing growth rates over 2012-2014, as a result of market saturation and policies containing the diffusion of solar plants on greenfields. We found important differences in the density of ground-mounted solar plants between northern and southern Italian municipalities. We identified accessible rural municipalities in southern Italy with intermediate population density and large availability of non-urban land as the most exposed to the diffusion of solar plants on greenfields in the last decade. Our approach is a promising tool to estimate changes in the use of land driven by the expansion of photovoltaic fields into rural land.« less
2014-04-30
CAPE CANAVERAL, Fla. – Engineers and technicians check NASA's Project Morpheus prototype lander after it touched down on a dedicated landing pad inside the autonomous landing and hazard avoidance technology, or ALHAT, hazard field at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. Morpheus launched on a free-flight test from a new launch pad at the north end of the landing facility. The 98-second test began at 1:57 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending more than 800 feet at a peak speed of 36 mph. The vehicle, with its recently installed ALHAT sensors, surveyed the hazard field to determine safe landing sites. Morpheus then flew forward and downward covering approximately 1300 feet while performing a 78-foot divert to simulate a hazard avoidance maneuver before landing on the dedicated pad inside the ALHAT hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, which are green propellants. These new capabilities could be used in future efforts to deliver cargo to planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
Forest inventory with LiDAR and stereo DSM on Washington department of natural resources lands
Jacob L. Strunk; Peter J. Gould
2015-01-01
DNRâs forest inventory group has completed its first version of a new remote-sensing based forest inventory system covering 1.4 million acres of DNR forest lands. We use a combination of field plots, lidar, NAIP, and a NAIP-derived canopy surface DSM. Given that height drives many key inventory variables (e.g. height, volume, biomass, carbon), remote-sensing derived...
NASA Astrophysics Data System (ADS)
Qian, Y.; Wang, C.; Huang, M.; Berg, L. K.; Duan, Q.; Feng, Z.; Shrivastava, M. B.; Shin, H. H.; Hong, S. Y.
2016-12-01
This study aims to quantify the relative importance and uncertainties of different physical processes and parameters in affecting simulated surface fluxes and land-atmosphere coupling strength over the Amazon region. We used two-legged coupling metrics, which include both terrestrial (soil moisture to surface fluxes) and atmospheric (surface fluxes to atmospheric state or precipitation) legs, to diagnose the land-atmosphere interaction and coupling strength. Observations made using the Department of Energy's Atmospheric Radiation Measurement (ARM) Mobile Facility during the GoAmazon field campaign together with satellite and reanalysis data are used to evaluate model performance. To quantify the uncertainty in physical parameterizations, we performed a 120 member ensemble of simulations with the WRF model using a stratified experimental design including 6 cloud microphysics, 3 convection, 6 PBL and surface layer, and 3 land surface schemes. A multiple-way analysis of variance approach is used to quantitatively analyze the inter- and intra-group (scheme) means and variances. To quantify parameter sensitivity, we conducted an additional 256 WRF simulations in which an efficient sampling algorithm is used to explore the multiple-dimensional parameter space. Three uncertainty quantification approaches are applied for sensitivity analysis (SA) of multiple variables of interest to 20 selected parameters in YSU PBL and MM5 surface layer schemes. Results show consistent parameter sensitivity across different SA methods. We found that 5 out of 20 parameters contribute more than 90% total variance, and first-order effects dominate comparing to the interaction effects. Results of this uncertainty quantification study serve as guidance for better understanding the roles of different physical processes in land-atmosphere interactions, quantifying model uncertainties from various sources such as physical processes, parameters and structural errors, and providing insights for improving the model physics parameterizations.
NASA Astrophysics Data System (ADS)
Gålfalk, Magnus; Karlson, Martin; Crill, Patrick; Bastviken, David
2017-04-01
The calibration and validation of remote sensing land cover products is highly dependent on accurate ground truth data, which are costly and practically challenging to collect. This study evaluates a novel and efficient alternative to field surveys and UAV imaging commonly applied for this task. The method consists of i) a light weight, water proof, remote controlled RGB-camera mounted on an extendable monopod used for acquiring wide-field images of the ground from a height of 4.5 meters, and ii) a script for semi-automatic image classification. In the post-processing, the wide-field images are corrected for optical distortion and geometrically rectified so that the spatial resolution is the same over the surface area used for classification. The script distinguishes land surface components by color, brightness and spatial variability. The method was evaluated in wetland areas located around Abisko, northern Sweden. Proportional estimates of the six main surface components in the wetlands (wet and dry Sphagnum, shrub, grass, water, rock) were derived for 200 images, equivalent to 10 × 10 m field plots. These photo plots were then used as calibration data for a regional scale satellite based classification which separates the six wetland surface components using a Sentinel-1 time series. The method presented in this study is accurate, rapid, robust and cost efficient in comparison to field surveys (time consuming) and drone mapping (which require low wind speeds and no rain, suffer from battery limited flight times, have potential GPS/compass errors far north, and in some areas are prohibited by law).
Analysing land cover and land use change in the Matobo National Park and surroundings in Zimbabwe
NASA Astrophysics Data System (ADS)
Scharsich, Valeska; Mtata, Kupakwashe; Hauhs, Michael; Lange, Holger; Bogner, Christina
2016-04-01
Natural forests are threatened worldwide, therefore their protection in National Parks is essential. Here, we investigate how this protection status affects the land cover. To answer this question, we analyse the surface reflectance of three Landsat images of Matobo National Park and surrounding in Zimbabwe from 1989, 1998 and 2014 to detect changes in land cover in this region. To account for the rolling countryside and the resulting prominent shadows, a topographical correction of the surface reflectance was required. To infer land cover changes it is not only necessary to have some ground data for the current satellite images but also for the old ones. In particular for the older images no recent field study could help to reconstruct these data reliably. In our study we follow the idea that land cover classes of pixels in current images can be transferred to the equivalent pixels of older ones if no changes occurred meanwhile. Therefore we combine unsupervised clustering with supervised classification as follows. At first, we produce a land cover map for 2014. Secondly, we cluster the images with clara, which is similar to k-means, but suitable for large data sets. Whereby the best number of classes were determined to be 4. Thirdly, we locate unchanged pixels with change vector analysis in the images of 1989 and 1998. For these pixels we transfer the corresponding cluster label from 2014 to 1989 and 1998. Subsequently, the classified pixels serve as training data for supervised classification with random forest, which is carried out for each image separately. Finally, we derive land cover classes from the Landsat image in 2014, photographs and Google Earth and transfer them to the other two images. The resulting classes are shrub land; forest/shallow waters; bare soils/fields with some trees/shrubs; and bare light soils/rocks, fields and settlements. Subsequently the three different classifications are compared and land changes are mapped. The main changes are observable in the surroundings of the National Park, especially the common lands have lost their clear boundaries with time. In the National Park, the area of forest increases from 1989 to 2014 from 58% to 61% whereas the area of shrub land decreases by the same amount. The amount of each of the other two classes remains constant. These changes indicate an actual effect of the protection status of the National Park. In our study remote sensing data are the main source to evaluate the effects and the benefits of a protected area without on-side studies. This could be important for regions, where field studies are not possible because of insecure political conditions and only remote sensing data are available.
NASA Technical Reports Server (NTRS)
Koster, Randal D.; Fekete, Balazs M.; Huffman, George J.; Stackhouse, Paul W.
2006-01-01
The International Satellite Land Surface Climatology Project Initiative 2 (ISLSCP-2) data set provides the data needed to characterize the surface water budget across much of the globe in terms of energy availability (net radiation) and water availability (precipitation) controls. The data, on average, are shown to be consistent with Budyko s decades-old framework, thereby demonstrating the continuing relevance of Budyko s semiempirical relationships. This consistency, however, appears only when a small subset of the data with hydrologically suspicious behavior is removed from the analysis. In general, the precipitation, net radiation, and runoff data also appear consistent in their interannual variability and in the phasing of their seasonal cycles.
Land Husbandry: Biochar application to reduce land degradation and erosion on cassava production
NASA Astrophysics Data System (ADS)
Yuniwati, E. D.
2017-12-01
This field experiment was carried out to examine the effect of increasing crop yield on land degradation and erosion in cassava-based cropping systems. The experiment was also aimed at showing that with proper crop management, the planting of cassava does not result in land degradation, and therefore, a sustainable production system can be obtained. The experiment was done in a farmer's fields in Batu, about 15 km south east of Malang, East Java, Indonesia. The soils are Alfisols with a surface slope of about 8%. There were 8 experimental treatments with two replications. The experiment results show that biochar applications reduce of soil erosion rate of the cassava field were not necessarily higher than those of maize in terms of crop yield and crop management. At low-to-medium yield, also observed the nutrient uptake of cassava was lower than that of maize. At high yield, only the K uptake of cassava was higher than that of maize, whereas the N and P uptake was more or less similar. Soil erosion on the cassava field was significantly higher than that on the maize field; however, this only occurred when there was no suitable crop management. Simple crop managements, such as ridging, biochar application, or manure application could significantly reduce soil erosion. The results also revealed that proper management could prevent land degradation and increase crop yield. In turn, the increase in crop yield could decrease soil erosion and plant nutrient depletion.
Towards Full Aircraft Airframe Noise Prediction: Lattice Boltzmann Simulations
NASA Technical Reports Server (NTRS)
Khorrami, Mehdi R.; Fares, Ehab; Casalino, Damiano
2014-01-01
Computational results for an 18%-scale, semi-span Gulfstream aircraft model are presented. Exa Corporation's lattice Boltzmann PowerFLOW(trademark) solver was used to perform time-dependent simulations of the flow field associated with this high-fidelity aircraft model. The simulations were obtained for free-air at a Mach number of 0.2 with the flap deflected at 39 deg (landing configuration). We focused on accurately predicting the prominent noise sources at the flap tips and main landing gear for the two baseline configurations, namely, landing flap setting without and with gear deployed. Capitalizing on the inherently transient nature of the lattice Boltzmann formulation, the complex time-dependent flow features associated with the flap were resolved very accurately and efficiently. To properly simulate the noise sources over a broad frequency range, the tailored grid was very dense near the flap inboard and outboard tips. Extensive comparison of the computed time-averaged and unsteady surface pressures with wind tunnel measurements showed excellent agreement for the global aerodynamic characteristics and the local flow field at the flap inboard and outboard tips and the main landing gear. In particular, the computed fluctuating surface pressure field for the flap agreed well with the measurements in both amplitude and frequency content, indicating that the prominent airframe noise sources at the tips were captured successfully. Gear-flap interaction effects were remarkably well predicted and were shown to affect only the inboard flap tip, altering the steady and unsteady pressure fields in that region. The simulated farfield noise spectra for both baseline configurations, obtained using a Ffowcs-Williams and Hawkings acoustic analogy approach, were shown to be in close agreement with measured values.
Code of Federal Regulations, 2011 CFR
2011-07-01
... reaching surface waters. (3) Multi-year phosphorus application means phosphorus applied to a field in excess of the crop needs for that year. In multi-year phosphorus applications, no additional manure... phosphorus has been removed from the field via harvest and crop removal. (c) Requirement to develop and...
Code of Federal Regulations, 2010 CFR
2010-07-01
... reaching surface waters. (3) Multi-year phosphorus application means phosphorus applied to a field in excess of the crop needs for that year. In multi-year phosphorus applications, no additional manure... phosphorus has been removed from the field via harvest and crop removal. (c) Requirement to develop and...
Assessment of the Georgia P Index on-farm at the field scale for grassland management
USDA-ARS?s Scientific Manuscript database
In order to better manage agricultural phosphorus (P), most states in the USA have adopted a “P indexing” approach which ranks fields according to potential losses of P. In Georgia, the Georgia P Index was developed to estimate the risk of bioavailable P loss from agricultural land to surface water...
USDA-ARS?s Scientific Manuscript database
Relating field observations of plant phenological events to remotely sensed depictions of land surface phenology remains a challenge to the vertical integration of data from disparate sources. This research conducted at the Jornada Basin Long-Term Ecological Research site in southern New Mexico cap...
USDA-ARS?s Scientific Manuscript database
Relating field observations of plan phonological events to remotely sensed depictions of land surface phenology remains a challenge to the vertical integration of data from disparate sources. This research conducted at the Jornada Basin Long-Term Ecological Research site in southern New Mexico capit...
Mars, John L.; Garrity, Christopher P.; Houseknecht, David W.; Amoroso, Lee; Meares, Donald C.
2007-01-01
Introduction The northeastern part of the National Petroleum Reserve in Alaska (NPRA) has become an area of active petroleum exploration during the past five years. Recent leasing and exploration drilling in the NPRA requires the U.S. Bureau of Land Management (BLM) to manage and monitor a variety of surface activities that include seismic surveying, exploration drilling, oil-field development drilling, construction of oil-production facilities, and construction of pipelines and access roads. BLM evaluates a variety of permit applications, environmental impact studies, and other documents that require rapid compilation and analysis of data pertaining to surface and subsurface geology, hydrology, and biology. In addition, BLM must monitor these activities and assess their impacts on the natural environment. Timely and accurate completion of these land-management tasks requires elevation, hydrologic, geologic, petroleum-activity, and cadastral data, all integrated in digital formats at a higher resolution than is currently available in nondigital (paper) formats. To support these land-management tasks, a series of maps was generated from remotely sensed data in an area of high petroleum-industry activity (fig. 1). The maps cover an area from approximately latitude 70?00' N. to 70?30' N. and from longitude 151?00' W. to 153?10' W. The area includes the Alpine oil field in the east, the Husky Inigok exploration well (site of a landing strip) in the west, many of the exploration wells drilled in NPRA since 2000, and the route of a proposed pipeline to carry oil from discovery wells in NPRA to the Alpine oil field. This map area is referred to as the 'Fish Creek area' after a creek that flows through the region. The map series includes (1) a color shaded-relief map based on 5-m-resolution data (sheet 1), (2) a surface-classification map based on 30-m-resolution data (sheet 2), and (3) a 5-m-resolution shaded relief-surface classification map that combines the shaded-relief and surface-classification data (sheet 3). Remote sensing datasets that were used to compile the maps include Landsat 7 Enhanced Thematic Mapper+ (ETM+), and interferometric synthetic aperture radar (IFSAR) data. In addition, a 1:250,000-scale geologic map of the Harrison Bay quadrangle, Alaska (Carter and Galloway, 1985, 2005) was used in conjunction with ETM+ and IFSAR data.
Soil moisture profile variability in land-vegetation- atmosphere continuum
NASA Astrophysics Data System (ADS)
Wu, Wanru
Soil moisture is of critical importance to the physical processes governing energy and water exchanges at the land-air boundary. With respect to the exchange of water mass, soil moisture controls the response of the land surface to atmospheric forcing and determines the partitioning of precipitation into infiltration and runoff. Meanwhile, the soil acts as a reservoir for the storage of liquid water and slow release of water vapor into the atmosphere. The major motivation of the study is that the soil moisture profile is thought to make a substantial contribution to the climate variability through two-way interactions between the land-surface and the atmosphere in the coupled ocean-atmosphere-land climate system. The characteristics of soil moisture variability with soil depth may be important in affecting the atmosphere. The natural variability of soil moisture profile is demonstrated using observations. The 16-year field observational data of soil moisture with 11-layer (top 2.0 meters) measured soil depths over Illinois are analyzed and used to identify and quantify the soil moisture profile variability, where the atmospheric forcing (precipitation) anomaly propagates down through the land-branch of the hydrological cycle with amplitude damping, phase shift, and increasing persistence. Detailed statistical data analyses, which include application of the periodogram method, the wavelet method and the band-pass filter, are made of the variations of soil moisture profile and concurrently measured precipitation for comparison. Cross-spectral analysis is performed to obtain the coherence pattern and phase correlation of two time series for phase shift and amplitude damping calculation. A composite of the drought events during this time period is analyzed and compared with the normal (non-drought) case. A multi-layer land surface model is applied for modeling the soil moisture profile variability characteristics and investigating the underlying mechanisms. Numerical experiments are conducted to examine the impacts of some potential controlling factors, which include atmospheric forcing (periodic and pulse) at the upper boundary, the initial soil moisture profile, the relative root abundance and the soil texture, on the variability of soil moisture profile and the corresponding evapotranspiration. Similar statistical data analyses are performed for the experimental data. Observations from the First International Satellite Land Surface Climatological Project (ISLSCP) Field Experiment (FIFE) are analyzed and used for the testing of model. The integration of the observational and modeling approaches makes it possible to better understand the mechanisms by which the soil moisture profile variability is generated with phase shift, fluctuation amplitude damping and low-pass frequency filtering with soil depth, to improve the strategies of parameterizations in land surface schemes, and furthermore, to assess its contribution to climate variability.
NASA Technical Reports Server (NTRS)
Mantovani, J. G.; Tamasy, G. J.; Mueller, R. P.; Townsend, I. I.; Sampson, J. W.; Lane, M. A.
2016-01-01
NASA Kennedy Space Center (KSC) is developing a new deployable launch system capability to support a small class of launch vehicles for NASA and commercial space companies to test and launch their vehicles. The deployable launch pad concept was first demonstrated on a smaller scale at KSC in 2012 in support of NASA Johnson Space Center's Morpheus Lander Project. The main objective of the Morpheus Project was to test a prototype planetary lander as a vertical takeoff and landing test-bed for advanced spacecraft technologies using a hazard field that KSC had constructed at the Shuttle Landing Facility (SLF). A steel pad for launch or landing was constructed using a modular design that allowed it to be reconfigurable and expandable. A steel flame trench was designed as an optional module that could be easily inserted in place of any modular steel plate component. The concept of a transportable modular launch and landing pad may also be applicable to planetary surfaces where the effects of rocket exhaust plume on surface regolith is problematic for hardware on the surface that may either be damaged by direct impact of high speed dust particles, or impaired by the accumulation of dust (e.g., solar array panels and thermal radiators). During the Morpheus free flight campaign in 2013-14, KSC performed two studies related to rocket plume effects. One study compared four different thermal ablatives that were applied to the interior of a steel flame trench that KSC had designed and built. The second study monitored the erosion of a concrete landing pad following each landing of the Morpheus vehicle on the same pad located in the hazard field. All surfaces of a portable flame trench that could be directly exposed to hot gas during launch of the Morpheus vehicle were coated with four types of ablatives. All ablative products had been tested by NASA KSC and/or the manufacturer. The ablative thicknesses were measured periodically following the twelve Morpheus free flight tests. The thermal energy from the Morpheus rocket exhaust plume was only found to be sufficient to cause appreciable ablation of one of the four ablatives that were tested. The rocket exhaust plume did cause spalling of concrete during each descent and landing on a landing pad in the hazard field. The Extended Abstract ASE Earth and Space Conference April, 2016 - Orlando, FL concrete surface was laser scanned following each Morpheus landing, and the total volume of spalled concrete that eroded between the first and final landings of the Morpheus Project's test campaign was estimated. This paper will also describe a new deployable launch system (DLS) capability that is being developed at KSC and was publicly announced in May 2015 (KSC Partnerships, 2015). The DLS is a set of multi-user Ground Support Equipment that will be used to test and launch small class launch vehicles. The system is comprised of four main elements: the Launch Stand, the Flame Deflector, the Pad Apron and the KAMAG transporter. The system elements are designed to be deployed at launch or test sites within the KSC/CCAFS boundaries. The DLS is intended to be used together with the Fluid and Electrical System of the Universal Propellant Servicing Systems and Mobile Power Data and Communications Unit.
NASA Technical Reports Server (NTRS)
Mantovani, James; Tamasy, Gabor; Mueller, Rob; Townsend, Van; Sampson, Jeff; Lane, Mike
2016-01-01
NASA Kennedy Space Center (KSC) is developing a new deployable launch system capability to support a small class of launch vehicles for NASA and commercial space companies to test and launch their vehicles. The deployable launch pad concept was first demonstrated on a smaller scale at KSC in 2012 in support of NASA Johnson Space Center's Morpheus Lander Project. The main objective of the Morpheus Project was to test a prototype planetary lander as a vertical takeoff and landing test-bed for advanced spacecraft technologies using a hazard field that KSC had constructed at the Shuttle Landing Facility (SLF). A steel pad for launch or landing was constructed using a modular design that allowed it to be reconfigurable and expandable. A steel flame trench was designed as an optional module that could be easily inserted in place of any modular steel plate component. The concept of a transportable modular launch and landing pad may also be applicable to planetary surfaces where the effects of rocket exhaust plume on surface regolith is problematic for hardware on the surface that may either be damaged by direct impact of high speed dust particles, or impaired by the accumulation of dust (e.g., solar array panels and thermal radiators). During the Morpheus free flight campaign in 2013-14, KSC performed two studies related to rocket plume effects. One study compared four different thermal ablatives that were applied to the interior of a steel flame trench that KSC had designed and built. The second study monitored the erosion of a concrete landing pad following each landing of the Morpheus vehicle on the same pad located in the hazard field. All surfaces of a portable flame trench that could be directly exposed to hot gas during launch of the Morpheus vehicle were coated with four types of ablatives. All ablative products had been tested by NASA KSC and/or the manufacturer. The ablative thicknesses were measured periodically following the twelve Morpheus free flight tests. The thermal energy from the Morpheus rocket exhaust plume was only found to be sufficient to cause appreciable ablation of one of the four ablatives that were tested. The rocket exhaust plume did cause spalling of concrete during each descent and landing on a landing pad in the hazard field. The Extended Abstract ASE Earth and Space Conference April, 2016 - Orlando, FL concrete surface was laser scanned following each Morpheus landing, and the total volume of spalled concrete that eroded between the first and final landings of the Morpheus Project's test campaign was estimated. This paper will also describe a new deployable launch system (DLS) capability that is being developed at KSC and was publicly announced in May 2015 (KSC Partnerships, 2015). The DLS is a set of multi-user Ground Support Equipment that will be used to test and launch small class launch vehicles. The system is comprised of four main elements: the Launch Stand, the Flame Deflector, the Pad Apron and the KAMAG transporter. The system elements are designed to be deployed at launch or test sites within the KSC/CCAFS boundaries. The DLS is intended to be used together with the Fluid and Electrical System of the Universal Propellant Servicing Systems and Mobile Power Data and Communications Unit
Land Surface Temperature Measurements from EOS MODIS Data
NASA Technical Reports Server (NTRS)
Wan, Zhengming
1997-01-01
We applied the multi-method strategy of land-surface temperature (LST) and emissivity measurements in two field campaigns this year for validating the MODIS LST algorithm. The first field campaign was conducted in Death Valley, CA, on March 3rd and the second one in Railroad Valley, NV, on June 23-27. ER2 MODIS Airborne Simulator (MAS) data were acquired in morning and evening for these two field campaigns. TIR spectrometer, radiometer, and thermistor data were also collected in the field campaigns. The LST values retrieved from MAS data with the day/night LST algorithm agree with those obtained from ground-based measurements within 1 C and show close correlations with topographic maps. The band emissivities retrieved from MAS data show close correlations with geological maps in the Death Valley field campaign. The comparison of measurement data in the latest Railroad Valley field campaign indicates that we are approaching the goals of the LST validation: LST uncertainty less than 0.5 C, and emissivity uncertainty less than 0.005 in the 10-13 spectral range. Measurement data show that the spatial variation in LST is the major uncertainty in the LST validation. In order to reduce this uncertainty, a new component of the multi-method strategy has been identified.
Soft Landing of Bare Nanoparticles with Controlled Size, Composition, and Morphology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Johnson, Grant E.; Colby, Robert J.; Laskin, Julia
2015-01-01
A kinetically-limited physical synthesis method based on magnetron sputtering and gas aggregation has been coupled with size-selection and ion soft landing to prepare bare metal nanoparticles on surfaces with controlled coverage, size, composition, and morphology. Employing atomic force microscopy (AFM) and scanning electron microscopy (SEM), it is demonstrated that the size and coverage of bare nanoparticles soft landed onto flat glassy carbon and silicon as well as stepped graphite surfaces may be controlled through size-selection with a quadrupole mass filter and the length of deposition, respectively. The bare nanoparticles are observed with AFM to bind randomly to the flat glassymore » carbon surface when soft landed at relatively low coverage (1012 ions). In contrast, on stepped graphite surfaces at intermediate coverage (1013 ions) the soft landed nanoparticles are shown to bind preferentially along step edges forming extended linear chains of particles. At the highest coverage (5 x 1013 ions) examined in this study the nanoparticles are demonstrated with both AFM and SEM to form a continuous film on flat glassy carbon and silicon surfaces. On a graphite surface with defects, however, it is shown with SEM that the presence of localized surface imperfections results in agglomeration of nanoparticles onto these features and the formation of neighboring depletion zones that are devoid of particles. Employing high resolution scanning transmission electron microscopy in the high angular annular dark field imaging mode (STEM-HAADF) and electron energy loss spectroscopy (EELS) it is demonstrated that the magnetron sputtering/gas aggregation synthesis technique produces single metal particles with controlled morphology as well as bimetallic alloy nanoparticles with clearly defined core-shell structure. Therefore, this kinetically-limited physical synthesis technique, when combined with ion soft landing, is a versatile complementary method for preparing a wide range of bare supported nanoparticles with selected properties that are free of the solvent, organic capping agents, and residual reactants present with nanoparticles synthesized in solution.« less
NASA Astrophysics Data System (ADS)
Guilloteau, C.; Foufoula-Georgiou, E.; Kummerow, C.; Kirstetter, P. E.
2017-12-01
A multiscale approach is used to compare precipitation fields retrieved from GMI using the last version of the GPROF algorithm (GPROF-2017) to the DPR fields all over the globe. Using a wavelet-based spectral analysis, which renders the multi-scale decompositions of the original fields independent of each other spatially and across scales, we quantitatively assess the various scales of variability of the retrieved fields, and thus define the spatially-variable "effective resolution" (ER) of the retrievals. Globally, a strong agreement is found between passive microwave and radar patterns at scales coarser than 80km. Over oceans the patterns match down to the 20km scale. Over land, comparison statistics are spatially heterogeneous. In most areas a strong discrepancy is observed between passive microwave and radar patterns at scales finer than 40-80km. The comparison is also supported by ground-based observations over the continental US derived from the NOAA/NSSL MRMS suite of products. While larger discrepancies over land than over oceans are classically explained by land complex surface emissivity perturbing the passive microwave retrieval, other factors are investigated here, such as intricate differences in the storm structure over oceans and land. Differences in term of statistical properties (PDF of intensities and spatial organization) of precipitation fields over land and oceans are assessed from radar data, as well as differences in the relation between the 89GHz brightness temperature and precipitation. Moreover, the multiscale approach allows quantifying the part of discrepancies caused by miss-match of the location of intense cells and instrument-related geometric effects. The objective is to diagnose shortcomings of current retrieval algorithms such that targeted improvements can be made to achieve over land the same retrieval performance as over oceans.
30 CFR 756.16 - Approval of the Hopi Tribe's abandoned mine land reclamation plan.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 86039, Telephone: (520) 734-2441. (b) Office of Surface Mining Reclamation and Enforcement, Albuquerque Field Office, 505 Marquette Ave., NW., Suite 1200, Albuquerque, NM 87102, Telephone: (505) 248-5070. [61...
30 CFR 756.16 - Approval of the Hopi Tribe's abandoned mine land reclamation plan.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 86039, Telephone: (520) 734-2441. (b) Office of Surface Mining Reclamation and Enforcement, Albuquerque Field Office, 505 Marquette Ave., NW., Suite 1200, Albuquerque, NM 87102, Telephone: (505) 248-5070. [61...
30 CFR 756.16 - Approval of the Hopi Tribe's abandoned mine land reclamation plan.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 86039, Telephone: (520) 734-2441. (b) Office of Surface Mining Reclamation and Enforcement, Albuquerque Field Office, 505 Marquette Ave., NW., Suite 1200, Albuquerque, NM 87102, Telephone: (505) 248-5070. [61...
30 CFR 756.16 - Approval of the Hopi Tribe's abandoned mine land reclamation plan.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 86039, Telephone: (520) 734-2441. (b) Office of Surface Mining Reclamation and Enforcement, Albuquerque Field Office, 505 Marquette Ave., NW., Suite 1200, Albuquerque, NM 87102, Telephone: (505) 248-5070. [61...
30 CFR 756.16 - Approval of the Hopi Tribe's abandoned mine land reclamation plan.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 86039, Telephone: (520) 734-2441. (b) Office of Surface Mining Reclamation and Enforcement, Albuquerque Field Office, 505 Marquette Ave., NW., Suite 1200, Albuquerque, NM 87102, Telephone: (505) 248-5070. [61...
NASA Astrophysics Data System (ADS)
Aichele, Stephen S.; Andresen, Jeffrey A.
2013-04-01
SummaryImpervious surface has been recognized as a key indicator of watershed health and function. The rapid expansion of impervious surface associated with periurban development following the Second World War resulted in concerns that impervious surface would alter flow characteristics, water quality, sediment, and stream morphology. These effects have been documented in studies across many disciplines. Unfortunately, impervious surface is difficult to measure directly, and other forms of land-use data are often substituted as surrogates. This paper highlights the shortcomings in land-use data, particularly parcel-based land-use data, as a surrogate for impervious surface in a periurban environment. Periurban development has changed substantially in the last several decades. This study investigates changes in the form of periurban development in Oakland County, Michigan, from 1945 to 2005, with an emphasis on the accumulation of impervious surface. We first evaluate patterns in the sizes of parcels being developed to residential uses. Using an impervious surface map derived from aerial imagery, we then calculate amount of impervious surface created by different forms of development, both in parcels of similar sizes developed at different times, and across parcel sizes for the period of the study. The results indicate substantial variability in impervious surface within periurban residential development, from 5.4% of parcel area to 25.4% of total parcel area depending on parcel size. Even within relatively specific categories (for example, residential parcels less than 743 square metre) impervious surface varied between 18.5% and 34.6% of the parcel area between 1945 and 2000. Since 1980, the trend has been toward larger parcel sizes with lower impervious surface ratios. The overall effect is that land is being developed at a rate substantially greater than the rate impervious surface is being created. The bias created by the trend to larger parcel sizes with smaller impervious surface ratios results in a tendency to overestimate the effects of recent land development. In combination with the change in character of suburban development, this bias has a tendency to overestimate the hydrologic response to new development. This overestimation is easily overlooked because it is consistent with the expected effect of urbanization. However, this effect helps explain observed field results indicating little change in streamflow through time despite significant apparent periurban development.
NASA Astrophysics Data System (ADS)
Smits, K. M.; Forsythe, L.; Riley, W. J.; Bisht, G.
2016-12-01
Land Surface Models (LSMs) are used to predict heat, energy, and momentum fluxesoccurring at the land surface and the resulting effects in the soil and atmosphere at various scales.Evaporation from bare soil is an integral component of the water balance that is very difficult toaccurately predict since it is complexly affected by the coupled effects of atmospheric conditions andsoil properties. Inaccurate or simplifying assumptions can have drastic effects on regional and globalLSM predictions and cause available LSMs to predict conflicting values for the soil moistureconditions and surface fluxes (e.g. evapotranspiration, infiltration, run off). The goal of this work isto see how heterogeneities in soil properties can be properly represented with a soil resistance termthat accounts for physically based parameters of the soil system at the land-atmosphere interface.Utilizing a comprehensive, experimental dataset generated from a soil with known, heterogeneousproperties under highly controlled atmospheric conditions, we are able to compare the effectivenessof various parameterizations in two different models. The first being a multiphase, non-equilibrium,and non-isothermal model that minimizes the dependence on fitting parameters. The effects ofcertain mechanisms are better understood at this fine scale and incorporated into the land surfacecomponent of the Accelerated Climate Modeling for Energy project (ALM), which is focused oncapturing the interactions between the surface and the atmosphere at larger scales. The formulationsof the resistance parameter, soil water retention curve (SWRC), and diffusivity through partiallysaturated porous media are of particular interest. The fine scale model was used in conjunction withthe experimental data to test formulations before implementing them into the ACME Land Model(ALM). Effects of these alterations were compared to the existing mechanisms in ALM and thentested against lab and field scale data sets. Initial findings suggest the Tang and Riley (2013a) soilresistance more accurately reproduces results lab and field results on multiple scales whereheterogeneity is present. Further understanding of soil resistance will lead to more robust landsurface models which decrease the reliance on such empirical relationships.
Vertical Landing Aerodynamics of Reusable Rocket Vehicle
NASA Astrophysics Data System (ADS)
Nonaka, Satoshi; Nishida, Hiroyuki; Kato, Hiroyuki; Ogawa, Hiroyuki; Inatani, Yoshifumi
The aerodynamic characteristics of a vertical landing rocket are affected by its engine plume in the landing phase. The influences of interaction of the engine plume with the freestream around the vehicle on the aerodynamic characteristics are studied experimentally aiming to realize safe landing of the vertical landing rocket. The aerodynamic forces and surface pressure distributions are measured using a scaled model of a reusable rocket vehicle in low-speed wind tunnels. The flow field around the vehicle model is visualized using the particle image velocimetry (PIV) method. Results show that the aerodynamic characteristics, such as the drag force and pitching moment, are strongly affected by the change in the base pressure distributions and reattachment of a separation flow around the vehicle.
Comparing SMAP to Macro-scale and Hyper-resolution Land Surface Models over Continental U. S.
NASA Astrophysics Data System (ADS)
Pan, Ming; Cai, Xitian; Chaney, Nathaniel; Wood, Eric
2016-04-01
SMAP sensors collect moisture information in top soil at the spatial resolution of ~40 km (radiometer) and ~1 to 3 km (radar, before its failure in July 2015). Such information is extremely valuable for understanding various terrestrial hydrologic processes and their implications on human life. At the same time, soil moisture is a joint consequence of numerous physical processes (precipitation, temperature, radiation, topography, crop/vegetation dynamics, soil properties, etc.) that happen at a wide range of scales from tens of kilometers down to tens of meters. Therefore, a full and thorough analysis/exploration of SMAP data products calls for investigations at multiple spatial scales - from regional, to catchment, and to field scales. Here we first compare the SMAP retrievals to the Variable Infiltration Capacity (VIC) macro-scale land surface model simulations over the continental U. S. region at 3 km resolution. The forcing inputs to the model are merged/downscaled from a suite of best available data products including the NLDAS-2 forcing, Stage IV and Stage II precipitation, GOES Surface and Insolation Products, and fine elevation data. The near real time VIC simulation is intended to provide a source of large scale comparisons at the active sensor resolution. Beyond the VIC model scale, we perform comparisons at 30 m resolution against the recently developed HydroBloks hyper-resolution land surface model over several densely gauged USDA experimental watersheds. Comparisons are also made against in-situ point-scale observations from various SMAP Cal/Val and field campaign sites.
A four-layer model for the heat budget of homogeneous land surfaces
NASA Technical Reports Server (NTRS)
Choudhury, B. J.; Monteith, J. L.
1988-01-01
The present model envisions the heat balance of a homogeneous land surface in terms of available energy, a set of driving potentials, and parameters for the physical state of the soil and vegetation. Two unique features of the model are: (1) the expression of the interaction of evaporation from the soil and from foliage by changes in the value of the saturation vapor pressure deficit of air in the canopy (the conclusions of this interaction being consistent with field observations); and (2) the treatment of sensible and latent heat exchange between the atmosphere and a soil consisting of two discrete layers.
Duan, Si-Bo; Li, Zhao-Liang; Tang, Bo-Hui; Wu, Hua; Ma, Lingling; Zhao, Enyu; Li, Chuanrong
2013-01-01
To evaluate the in-flight performance of a new hyperspectral sensor onboard an unmanned aerial vehicle (UAV-HYPER), a comprehensive field campaign was conducted over the Baotou test site in China on 3 September 2011. Several portable reference reflectance targets were deployed across the test site. The radiometric performance of the UAV-HYPER sensor was assessed in terms of signal-to-noise ratio (SNR) and the calibration accuracy. The SNR of the different bands of the UAV-HYPER sensor was estimated to be between approximately 5 and 120 over the homogeneous targets, and the linear response of the apparent reflectance ranged from approximately 0.05 to 0.45. The uniform and non-uniform Lambertian land surface reflectance was retrieved and validated using in situ measurements, with root mean square error (RMSE) of approximately 0.01–0.07 and relative RMSE of approximately 5%–12%. There were small discrepancies between the retrieved uniform and non-uniform Lambertian land surface reflectance over the homogeneous targets and under low aerosol optical depth (AOD) conditions (AOD = 0.18). However, these discrepancies must be taken into account when adjacent pixels had large land surface reflectance contrast and under high AOD conditions (e.g. AOD = 1.0). PMID:23785513
Effect of canopy and topography induced wakes on land-atmosphere fluxes of momentum and scalars
NASA Astrophysics Data System (ADS)
Markfort, C. D.; Zhang, W.; Porté-Agel, F.; Stefan, H. G.
2012-04-01
Wakes shed from natural and anthropogenic landscape features affect land-atmosphere fluxes of momentum and scalars, including water vapor and trace gases (e.g. CO2). Canopies and bluff bodies, such as forests, buildings and topography, cause boundary layer flow separation, and lead to a break down of standard Monin-Obukhov similarity relationships in the atmospheric boundary layer (ABL). Wakes generated by these land surface features persist for significant distances (>100 typical length scales) and affect a large fraction of the Earth's terrestrial surface. This effect is currently not accounted for in land-atmosphere models, and little is known about how heterogeneity of wake-generating features affect land surface fluxes. Additionally flux measurements, made in wake-affected regions, do not satisfy the homogeneous flow requirements for the standard eddy correlation (EC) method. This phenomenon, often referred to as wind sheltering, has been shown to affect momentum and kinetic energy fluxes at the lake-atmosphere interface (Markfort et al. 2010). This presentation will highlight results from controlled wind tunnel experiments of neutral and thermally stratified boundary layers, using particle image velocimetry (PIV) and custom x-wire/cold-wire anemometry, to understand how the physical structure of upstream bluff bodies and porous canopies as well as how thermal stability affect the flow separation zone, boundary layer recovery and surface fluxes. We have found that there is a nonlinear relationship between canopy length/porosity and flow separation downwind of a canopy to clearing transition. Results will provide the basis for new parameterizations to account for wake effects on land-atmosphere fluxes and corrections for the EC measurements over open fields, lakes, and wetlands. Key words: Atmospheric boundary layer; Wakes; Stratification; Land-Atmosphere Parameterization; Canopy
NASA Technical Reports Server (NTRS)
Hoffman, Stephen J.; Leonard, Matther J.; Pacal, Lee
2011-01-01
This report covers the execution of and results from the activities proposed and approved in Exploration Analogs and Mission Development (EAMD) Field Test Protocol HMP2010: Evaluation of Robotic Systems to carry out Traverse Execution, Opportunistic Science, and Landing Site Evaluation Tasks. The field tests documented in this report examine one facet of a larger program of planetary surface exploration. This program has been evolving and maturing for several years, growing from a broad policy statement with a few specified milestones for NASA to an international effort with much higher fidelity descriptions of systems and operations necessary to accomplish this type of exploration.
Astronaut John Young photographed collecting lunar samples
NASA Technical Reports Server (NTRS)
1972-01-01
Astronaut John W. Young, commander of the Apollo 16 lunar landing mission, is photographed collecting lunar samples near North Ray crater during the third Apollo 16 extravehicular activity (EVA-3) at the Descartes landing site. This picture was taken by Astronaut Charles M. Duke Jr., lunar module pilot. Young is using the lunar surface rake and a set of tongs. The Lunar Roving Vehicle is parked in the field of large boulders in the background.
NASA Astrophysics Data System (ADS)
Zwartendijk, Bob; van Meerveld, Ilja; Ravelona, Maafaka; Razakamanarivo, Herintsitohaina; Ghimire, Chandra; Bruijnzeel, Sampurno; Jones, Julia
2015-04-01
Shortened slash-and-burn cycles exhaust agricultural land and have resulted in extensive tracts of highly degraded land across the tropics. Land degradation typically results in decreased rainfall infiltration due to a reduced field-saturated hydraulic conductivity of the topsoil because of a progressive decline in soil organic matter, exposure to raindrop impact, surface sealing and compaction. This results, in turn, in enhanced surface runoff and erosion, and consequently less subsurface flow and groundwater recharge. On the other hand, natural vegetation regrowth or active reforestation can lead to a renewed accumulation of soil organic matter, macropore development and increased infiltration rates. As part of the P4GES project (Can Paying 4 Global Ecosystem Services values reduce poverty?; www.p4ges.org), we study the effects of land use change and reforestation on water resources in the Corridor Ankeniheny-Zahamena (CAZ) in eastern Madagascar. In this poster, we present the results of infiltration and preferential flow measurements in four different land uses in the southern part of the CAZ: (i) closed canopy forest, (ii) 3-14 year-old regrowth on fallow land (savokas), (iii) exhausted and severely degraded land (tany maty), and (iv) recently reforested sites (6-8 years old). The results show that infiltrability increases significantly after several years of forest regrowth after land abandonment, but it remains unclear whether active replanting decreases the time required for restoration of soil hydrological functioning. Preferential flow pathways differed strikingly between the respective land cover types: infiltration in mature forests was predominantly characterized by macropore flow (preferential flow pathways), whereas infiltration in exhausted agricultural land was dominated by matrix flow (few preferential flow pathways). Occurrence of preferential flow pathways in reforestation and fallow sites varied considerably. These results suggest that land cover significantly affects hydrological flow pathways and that natural regeneration and active reforestation of degraded land can result in increased infiltration and a reduced likelihood for surface runoff.
Irrigated acreage and other land uses on the Snake River Plain, Idaho and eastern Oregon
Lindholm, Gerald F.; Goodell, S.A.
1986-01-01
Prompted by the need for a current, accurate, and repeatable delineation of irrigated acreage on the Snake River Plain, the U.S. Geological Survey entered into a cooperative agreement with the Idaho Department of Water Resources Image Analysis Facility and the U.S. Bureau of Reclamation to delineate 1980 land use form Landsat data. Irrigated acreage data were needed as input to groundwater flow models developed by the U.S. Geological Survey in a study of the regional aquifer system underlying the Snake River Plain. Single-date digital multispectral scanner data analyzed to delineate land-use classes. Source of irrigation water (surface water, ground water, and combined) was determined from county maps of 1975 water-related land use, data from previous investigations, and field checking. Surface-water diversions for irrigation on the Snake River Plain began in the 1840's. With the stimulus of Federal aid authorized by the Desert Land Act, Carey Act, and Reclamation Act, irrigated area increased rapidly in the early 1900's. By 1929, 2.2 million acres were irrigated. Ground water became and important source of irrigation water after World War II. In 1980, about 3.1 million acres of the Snake River Plain were irrigate: 2.0 million acres with surface water, 1.0 million with ground water, and 0.1 million with combined surface and ground water. About 5.2 million acres (half of the plain) are undeveloped rangeland, 1.0 million acres (one-tenth) are classified as barren. The remaining land is a mixture of dryland agriculture, water bodies, wetland, forests, and urban areas.
AVIRIS Land-Surface Mapping in Support of the Boreal Ecosystem-Atmosphere Study (BOREAS)
NASA Technical Reports Server (NTRS)
Roberts, Dar A.; Gamon, John; Keightley, Keir; Prentiss, Dylan; Reith, Ernest; Green, Robert
2001-01-01
A key scientific objective of the original Boreal Ecosystem-Atmospheric Study (BOREAS) field campaign (1993-1996) was to obtain the baseline data required for modeling and predicting fluxes of energy, mass, and trace gases in the boreal forest biome. These data sets are necessary to determine the sensitivity of the boreal forest biome to potential climatic changes and potential biophysical feedbacks on climate. A considerable volume of remotely-sensed and supporting field data were acquired by numerous researchers to meet this objective. By design, remote sensing and modeling were considered critical components for scaling efforts, extending point measurements from flux towers and field sites over larger spatial and longer temporal scales. A major focus of the BOREAS follow-on program is concerned with integrating the diverse remotely sensed and ground-based data sets to address specific questions such as carbon dynamics at local to regional scales. The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) has the potential of contributing to BOREAS through: (1) accurate retrieved apparent surface reflectance; (2) improved landcover classification; and (3) direct assessment of biochemical/biophysical information such as canopy liquid water and chlorophyll concentration through pigment fits. In this paper, we present initial products for major flux tower sites including: (1) surface reflectance of dominant cover types; (2) a land-cover classification developed using spectral mixture analysis (SMA) and Multiple Endmember Spectral Mixture Analysis (MESMA); and (3) liquid water maps. Our goal is to compare these land-cover maps to existing maps and to incorporate AVIRIS image products into models of photosynthetic flux.
NASA Astrophysics Data System (ADS)
Knight, J.; Adam, E.
2015-12-01
Mapping spatial patterns of soil organic carbon (SOC) using high resolution satellite imagery is especially important in inaccessible or upland areas that have limited field measurements, where land use and land cover (LULC) are changing rapidly, or where the land surface is sensitive to overgrazing and high rates of soil erosion and thus sediment, nutrient and carbon export. Here we outline the methods and results of mapping soil organic carbon in highland areas (~2400 m) of eastern Lesotho, southern Africa, across different land uses. Bedrock summit areas with very thin soils are dominated by xeric alpine grassland; terrace agriculture with strip fields and thicker soils is found within river valleys. Multispectral Worldview 2 imagery was used to map LULC across the region. An overall accuracy of 88% and kappa value of 0.83 were achieved using a support vector machine model. Soils were examined in the field from different LULC areas for properties such as soil depth, maturity and structure. In situ soils in the field were also evaluated using a portable analytical spectral device (ASD) in order to ground truth spectral signatures from Worldview. Soil samples were examined in the lab for chemical properties including organic carbon. Regression modeling was used in order to establish a relationship between soil characteristics and soil spectral reflectance. We were thus able to map SOC across this diverse landscape. Results show that there are notable differences in SOC between upland and agricultural areas which reflect both soil thickness and maturity, and land use practices such as manuring of fields by cattle. Soil erosion and thus carbon (nutrient) export is significant issue in this region, which this project will now be examining.
NASA Astrophysics Data System (ADS)
De Ridder, K.; Bertrand, C.; Casanova, G.; Lefebvre, W.
2012-09-01
Increasingly, mesoscale meteorological and climate models are used to predict urban weather and climate. Yet, large uncertainties remain regarding values of some urban surface properties. In particular, information concerning urban values for thermal roughness length and thermal admittance is scarce. In this paper, we present a method to estimate values for thermal admittance in combination with an optimal scheme for thermal roughness length, based on METEOSAT-8/SEVIRI thermal infrared imagery in conjunction with a deterministic atmospheric model containing a simple urbanized land surface scheme. Given the spatial resolution of the SEVIRI sensor, the resulting parameter values are applicable at scales of the order of 5 km. As a study case we focused on the city of Paris, for the day of 29 June 2006. Land surface temperature was calculated from SEVIRI thermal radiances using a new split-window algorithm specifically designed to handle urban conditions, as described inAppendix A, including a correction for anisotropy effects. Land surface temperature was also calculated in an ensemble of simulations carried out with the ARPS mesoscale atmospheric model, combining different thermal roughness length parameterizations with a range of thermal admittance values. Particular care was taken to spatially match the simulated land surface temperature with the SEVIRI field of view, using the so-called point spread function of the latter. Using Bayesian inference, the best agreement between simulated and observed land surface temperature was obtained for the Zilitinkevich (1970) and Brutsaert (1975) thermal roughness length parameterizations, the latter with the coefficients obtained by Kanda et al. (2007). The retrieved thermal admittance values associated with either thermal roughness parameterization were, respectively, 1843 ± 108 J m-2 s-1/2 K-1 and 1926 ± 115 J m-2 s-1/2 K-1.
AVIRIS Land-Surface Mapping in Support of the Boreal Ecosystem-Atmosphere Study
NASA Technical Reports Server (NTRS)
Green, R.; Roberts, D.; Gamon, J.; Keightley, K.; Prentiss, D.; Reith, E.
2000-01-01
A key scientific objective of the original BOREAS field campaign (1993-1996) was to obtain the baseline data required for modeling and predicting fluxes of energy, mass and trace gases in the boreal forest biome.
NASA Astrophysics Data System (ADS)
Christanto, N.; Sartohadi, J.; Setiawan, M. A.; Shrestha, D. B. P.; Jetten, V. G.
2018-04-01
Land use change influences the hydrological as well as landscape processes such as runoff and sediment yields. The main objectives of this study are to assess the land use change and its impact on the runoff and sediment yield of the upper Serayu Catchment. Land use changes of 1991 to 2014 have been analyzed. Spectral similarity and vegetation indices were used to classify the old image. Therefore, the present and the past images are comparable. The influence of the past and present land use on runoff and sediment yield has been compared with field measurement. The effect of land use changes shows the increased surface runoff which is the result of change in the curve number (CN) values. The study shows that it is possible to classify previously obtained image based on spectral characteristics and indices of major land cover types derived from recently obtained image. This avoids the necessity of having training samples which will be difficult to obtain. On the other hand, it also demonstrates that it is possible to link land cover changes with land degradation processes and finally to sedimentation in the reservoir. The only condition is the requirement for having the comparable dataset which should not be difficult to generate. Any variation inherent in the data which are other than surface reflectance has to be corrected.
NASA Technical Reports Server (NTRS)
Houser, Paul (Technical Monitor); Patton, Edward G.; Sullivan, Peter P.; Moeng, Chin-Hoh
2003-01-01
We examine the influence of surface heterogeneity on boundary layers using a large-eddy simulation coupled to a land-surface model. Heterogeneity, imposed in strips varying from 2-30 km (1 less than lambda/z(sub i) less than 18), is found to dramatically alter the structure of the free convective boundary layer by inducing significant organized circulations. A conditional sampling technique, based on the scale of the surface heterogeneity (phase averaging), is used to identify and quantify the organized surface fluxes and motions in the atmospheric boundary layer. The impact of the organized motions on turbulent transport depends critically on the scale of the heterogeneity lambda, the boundary layer height zi and the initial moisture state of the boundary layer. Dynamical and scalar fields respond differently as the scale of the heterogeneity varies. Surface heterogeneity of scale 4 less than lamba/z(sub i) less than 9 induces the strongest organized flow fields (up, wp) while heterogeneity with smaller or larger lambda/z(sub i) induces little organized motion. However, the organized components of the scalar fields (virtual potential temperature and mixing ratio) grow continuously in magnitude and horizontal scale, as lambda/z(sub i) increases. For some cases, the organized motions can contribute nearly 100% of the total vertical moisture flux. Patch-induced fluxes are shown to dramatically impact point measurements that assume the time-average vertical velocity to be zero. The magnitude and sign of this impact depends on the location of the measurement within the region of heterogeneity.
Assimilation of SMOS Retrieved Soil Moisture into the Land Information System
NASA Technical Reports Server (NTRS)
Blankenship, Clay; Case, Jonathan; Zavodsky, Bradley; Jedlovec, Gary
2014-01-01
Soil moisture retrievals from the Soil Moisture and Ocean Salinity (SMOS) instrument are assimilated into the Noah land surface model (LSM) within the NASA Land Information System (LIS). Before assimilation, SMOS retrievals are bias-corrected to match the model climatological distribution using a Cumulative Distribution Function (CDF) matching approach. Data assimilation is done via the Ensemble Kalman Filter. The goal is to improve the representation of soil moisture within the LSM, and ultimately to improve numerical weather forecasts through better land surface initialization. We present a case study showing a large area of irrigation in the lower Mississippi River Valley, in an area with extensive rice agriculture. High soil moisture value in this region are observed by SMOS, but not captured in the forcing data. After assimilation, the model fields reflect the observed geographic patterns of soil moisture. Plans for a modeling experiment and operational use of the data are given. This work helps prepare for the assimilation of Soil Moisture Active/Passive (SMAP) retrievals in the near future.
Blanchard, Paul J.
2002-01-01
The U.S. Environmental Protection Agency requested that the Navajo Nation conduct an assessment of aquifer sensitivity on Navajo Nation lands and an assessment of ground-water vulnerability to pesticide contamination on the Navajo Indian Irrigation Project. Navajo Nation lands include about 17,000 square miles in northeastern Arizona, northwestern New Mexico, and southeastern Utah. The Navajo Indian Irrigation Project in northwestern New Mexico is the largest area of agriculture on the Navajo Nation. The Navajo Indian Irrigation Project began operation in 1976; presently (2001) about 62,000 acres are available for irrigated agriculture. Numerous pesticides have been used on the Navajo Indian Irrigation Project during its operation. Aquifer sensitivity is defined by the U.S. Environmental Protection Agency as 'The relative ease with which a contaminant [pesticide] applied on or near a land surface can migrate to the aquifer of interest. Aquifer sensitivity is a function of the intrinsic characteristics of the geologic material in question, any underlying saturated materials, and the overlying unsaturated zone. Sensitivity is not dependent on agronomic practices or pesticide characteristics.' Ground-water vulnerability is defined by the U.S. Environmental Protection Agency as 'The relative ease with which a contaminant [pesticide] applied on or near a land surface can migrate to the aquifer of interest under a given set of agronomic management practices, pesticide characteristics, and aquifer sensitivity conditions.' The results of the aquifer sensitivity assessment on Navajo Nation and adjacent lands indicated relative sensitivity within the boundaries of the study area. About 22 percent of the study area was not an area of recharge to bedrock aquifers or an area of unconsolidated deposits and was thus assessed to have an insignificant potential for contamination. About 72 percent of the Navajo Nation study area was assessed to be in the categories of most potential or intermediate potential for contamination. About 6 percent of the study area was assessed to have the least potential for contamination, mostly in areas where the slope of the land surface is more than 12 percent. Nearly all fields on the Navajo Indian Irrigation Project were assessed to have the most potential for contamination. The assessment of ground-water vulnerability to pesticide contamination on the Navajo Indian Irrigation Project was based on pesticide application to various crops on part of the Navajo Indian Irrigation Project during 1997-99. The assessment indicated that ground water underlying fields of beans, wheat, barley, and alfalfa was most vulnerable to pesticide contamination; ground water underlying fields of corn and potatoes was intermediately vulnerable to pesticide contamination; and ground water underlying fields of hay was least vulnerable to pesticide contamination.
Can Airports be a Green Source of Energy?
NASA Astrophysics Data System (ADS)
Solus, Daniel; Archer, Charysse; Malone, Brandi; Chesterfield, Norrisha; Jackson, Lateria; Erenso, Daniel
2008-04-01
When Boeing 747 lands its energy (896MJ) is dissipated by friction. Our statistical analysis for commercial aircrafts landing at the Nashville International Airport (BNA) have discovered that nearly 30 average single family households can be powered by the dissipated energy on a monthly basis. It may be possible to land an airplane on a frictionless surface and transform its energy into electrical energy. To demonstrate this we have conducted theoretical and experimental studies using a conducting rod attached to a toy car sliding on a U-shaped conducting wire placed in a uniform magnetic field track. The results concluded that this technique requires a very strong magnetic field. We then used a cylindrical magnet mounted on toy trucks and set to roll on a track inside a solenoid and been able to generate an ac voltage (4-10 volts).
Crustal evolution inferred from Apollo magnetic measurements
NASA Technical Reports Server (NTRS)
Dyal, P.; Daily, W. D.; Vanian, L. L.
1978-01-01
The topology of lunar remanent fields is investigated by analyzing simultaneous magnetometer and solar wind spectrometer data. The diffusion model proposed by Vanyan (1977) to describe the field-plasma interaction at the lunar surface is extended to describe the interaction with fields characterized by two scale lengths, and the extended model is compared with data from three Apollo landing sites (Apollo 12, 15 and 16) with crustal fields of differing intensity and topology. Local remanent field properties from this analysis are compared with high spatial resolution magnetic maps obtained from the electron reflection experiment. It is concluded that remanent fields over most of the lunar surface are characterized by spatial variations as small as a few kilometers. Large regions (50 to 100 km) of the lunar crust were probably uniformly magnetized early in the evolution of the crust. Smaller scale (5 to 10 km) magnetic sources close to the surface were left by bombardment and subsequent gardening of the upper layers of these magnetized regions. The small scale sized remanent fields of about 100 gammas are measured by surface experiments, whereas the larger scale sized fields of about 0.1 gammas are measured by the orbiting subsatellite experiments.
Radiation Products based on a constellation of Geostationary Satellites
NASA Astrophysics Data System (ADS)
Trigo, I. F.; Freitas, S. C.; Barroso, C.; Macedo, J.; Perdigão, R.; Silva, R.; Viterbo, P.
2012-04-01
The various components of the surface radiation budget present high variability in time and space, particularly over land surfaces where spatial heterogeneity of the upward fluxes is high. Geostationary satellites are well-suited to describe the daily cycle of downward and upward radiation fluxes and present spatial resolutions of the order of 3-to-5 km at sub-satellite point, acceptable for many applications. The work presented here is being carried out within the framework of Geoland-2 project, and aims the use of data from geostationary platforms to generate, archive and distribute in near real time four component of the surface radiation budget: land surface albedo, land surface temperature (LST) and downward short- and long-wave fluxes at the surface. All four components are retrieved from the following satellites - GOES-W covering North and South America, Meteosat Second Generation (MSG) covering essentially Europe and Africa, and MTSAT covering part of Asia and Australia. The variables are retrieved independently from each satellite and then merged into a single field, with a 5 km spatial resolution. Data are generated hourly in the case of the downward fluxes and LST, and 10-daily in the case of albedo. In regions covered by both GOES and MSG disks, the interpolated field makes use of both retrievals, giving more weight to those with lower uncertainty. The four components of the surface radiation budget described above are assessed through comparisons with similar parameters retrieved from other sensors (e.g., MODIS, CERES) or from models (e.g., ECMWF forecasts), as well as with in situ observations when available. The presentation will be focused on a brief description of algorithms and auxiliary data used in product estimation. The results of inter-comparisons with other data sources, along with the identification of the retrieval conditions that allow optimal / sub-optimal estimation of these surface radiation parameters will also be analysed. The radiation products generated within the Geoland-2 project are freely available to the user community.
NASA Astrophysics Data System (ADS)
Ahlswede, B.; Thomas, R. Q.; O'Halloran, T. L.; Rady, J.; LeMoine, J.
2017-12-01
Changes in land-use and land management can have biogeochemical and biophysical effects on local and global climate. While managed ecosystems provide known food and fiber benefits, their influence on climate is less well quantified. In the southeastern United States, there are numerous types of intensely managed ecosystems but pine plantations and switchgrass fields represent two biogeochemical and biophysical extremes; a tall, low albedo forest with trees harvested after multiple decades vs. a short, higher albedo C4 grass field that is harvested annually. Despite the wide spread use of these ecosystems for timber and bioenergy, a quantitative, empirical evaluation of the net influence of these ecosystems on climate is lacking because it requires measuring both the greenhouse gas and energy balance of the ecosystems while controlling for the background weather and soil environment. To address this need, we established a pair of eddy flux towers in these ecosystems that are co-located (1.5 km apart) in Central Virginia and measured the radiative energy, non-radiative energy and carbon fluxes, along with associated biometeorology variables; the paired site has run since April 2016. During the first 1.5 years (two growing seasons), we found strong seasonality in the difference in surface temperature between the two ecosystems. In the growing seasons, both sites had similar surface temperature despite higher net radiation in pine. Following harvest of the switchgrass in September, the switchgrass temperatures increased relative to pine. In the winter, the pine ecosystem was warmer. We evaluate the drivers of these intra-annual dynamics and compare the climate influence of these biophysical differences to the differences in carbon fluxes between the sites using a suite of established climate regulation services metrics. Overall, our results show tradeoffs exist between the biogeochemical and biophysical climate services in managed ecosystems in the southeastern United States and highlight the importance of seasonality when quantifying how land-use and land-cover change influence climate. These data, when combined with earth system models, will help inform our understanding of how land-use and land change decisions in the southeastern United States will influence local, regional, and global climate.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Markham, B.L.; Halthore, R.N.; Goetz, S.J.
1992-11-30
This work is part of the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE), an international land-surface-atmosphere experiment aimed at improving the way climate models represent energy, water, heat, and carbon exchanges, and improving the utilization of satellite based remote sensing to monitor such parameters. This paper reports on comparison of measurement systems which were deployed to measure surface reflectance factors, from aircraft or satellites. These instruments look over the general range of 0.4 to 2.5[mu]m. Instruments studied include Landsat 5 thematic mapper (TM), the SPOT 1 high-resolution visible sensor (HRV) 1, the NS001 thematic mapper simulator,more » and the modular multispectral radiometers (MMRs). The study looked at the radiometric consistency of the different instruments, and the adequacy of the atmospheric correction routines applied to data analysis.« less
LandingNav: a precision autonomous landing sensor for robotic platforms on planetary bodies
NASA Astrophysics Data System (ADS)
Katake, Anup; Bruccoleri, Chrisitian; Singla, Puneet; Junkins, John L.
2010-01-01
Increased interest in the exploration of extra terrestrial planetary bodies calls for an increase in the number of spacecraft landing on remote planetary surfaces. Currently, imaging and radar based surveys are used to determine regions of interest and a safe landing zone. The purpose of this paper is to introduce LandingNav, a sensor system solution for autonomous landing on planetary bodies that enables landing on unknown terrain. LandingNav is based on a novel multiple field of view imaging system that leverages the integration of different state of the art technologies for feature detection, tracking, and 3D dense stereo map creation. In this paper we present the test flight results of the LandingNav system prototype. Sources of errors due to hardware limitations and processing algorithms were identified and will be discussed. This paper also shows that addressing the issues identified during the post-flight test data analysis will reduce the error down to 1-2%, thus providing for a high precision 3D range map sensor system.
NASA Technical Reports Server (NTRS)
Ryan, Robert; Underwood, Lauren; Holekamp, Kara; May, George; Spiering, Bruce; Davis, Bruce
2011-01-01
This technology exploits the organic decomposition capability and hydrophilic properties of the photocatalytic material titanium dioxide (TiO2), a nontoxic and non-hazardous substance, to address contamination and biofouling issues in field-deployed optical sensor systems. Specifically, this technology incorporates TiO2 coatings and materials applied to, or integrated as a part of, the optical surfaces of sensors and calibration sources, including lenses, windows, and mirrors that are used in remote, unattended, ground-based (land or maritime) optical sensor systems. Current methods used to address contamination or biofouling of these optical surfaces in deployed systems are costly, toxic, labor intensive, and non-preventative. By implementing this novel technology, many of these negative aspects can be reduced. The functionality of this innovative self-cleaning solution to address the problem of contamination or biofouling depends on the availability of a sufficient light source with the appropriate spectral properties, which can be attained naturally via sunlight or supplemented using artificial illumination such as UV LEDs (light emitting diodes). In land-based or above-water systems, the TiO2 optical surface is exposed to sunlight, which catalyzes the photocatalytic reaction, facilitating both the decomposition of inorganic and organic compounds, and the activation of superhydrophilic properties. Since underwater optical surfaces are submerged and have limited sunlight exposure, supplementary UV light sources would be required to activate the TiO2 on these optical surfaces. Nighttime operation of land-based or above-water systems would require this addition as well. For most superhydrophilic self-cleaning purposes, a rainwater wash will suffice; however, for some applications an attached rainwater collector/ dispenser or other fresh water dispensing system may be required to wash the optical surface and initiate the removal of contaminates. Deployment of this non-toxic,non-hazardous-technology will take advantage of environmental elements (i.e. rain and sunlight), increase the longevity of unattended optical systems, increase the amount of time between required maintenance, and improve the long-term accuracy of sensor measurements.
Rosetta Lander - Philae: preparations for landing on comet 67P/Churyumov-Gerasimenko
NASA Astrophysics Data System (ADS)
Ulamec, S.; Biele, J.; Jurado, E.; Gaudon, P.; Geurts, K.
2013-12-01
Rosetta is a Cornerstone Mission of the ESA Horizon 2000 programme. It is going to rendezvous with comet 67P/Churyumov-Gerasimenko after a ten year cruise and will study both its nucleus and coma with an orbiting spacecraft as well as with a Lander, Philae, that has been designed to land softly on the comet nucleus. Aboard Philae, a payload consisting of ten scientific instruments will perform in-situ studies of the cometary material. Philae will be separated from the mother spacecraft from a dedicated delivery trajectory. It then descends, ballistically, to the surface of the comet, stabilized with an internal flywheel. At touch-down anchoring harpoons will be fired and a damping mechanism within the landing gear will provide the lander from re-bouncing. Currently the characteristics of the nucleus of the comet are hardly known. Mapping with the orbiter cameras (shape, slopes, surface roughness) and essential measurements like gravity field, state of rotation or outgassing parameters can only be performed after arrival of the main spacecraft, between May and October 2014. These data will be used for selecting a landing site and defining the detailed landing strategy. Landing is foreseen for November 2014 at a heliocentric distance of 3 AU. The paper describes the Rosetta Lander system and its payload, but emphasizes on the preparations for landing, the landing site selection process and the planned operational timeline.
NASA Astrophysics Data System (ADS)
Fan, Yuanchao; Bernoux, Martial; Roupsard, Olivier; Panferov, Oleg; Le Maire, Guerric; Tölle, Merja; Knohl, Alexander
2014-05-01
Deforestation and forest degradation driven by the expansion of oil palm (Elaeis guineensis) plantations has become the major source of GHG emission in Indonesia. Changes of land surface properties (e.g. vegetation composition, soil property, surface albedo) associated with rainforest to oil palm conversion might alter the patterns of land-atmosphere energy, water and carbon cycles and therefore affect local or regional climate. Land surface modeling has been widely used to characterize the two-way interactions between climate and human disturbances on land surface. The Community Land Model (CLM) is a third-generation land model that simulates a wide range of biogeophysical and biogeochemical processes. This project utilizes the land-cover/land-use change (LCLUC) capability of the latest CLM versions 4/4.5 to characterize quantitatively how anthropogenic land surface dynamics in Indonesia affect land-atmosphere carbon, water and energy fluxes. Before simulating land use changes, the first objective is to parameterize and validate the CLM model at local rainforest and oil palm plantation sites through separate point simulations. This entails creation and parameterization of a new plant functional type (PFT) for oil palm, as well as sensitivity analysis and adaptation of model parameters for the rainforest PFTs. CLM modelled fluxes for the selected sites are to be compared with field observations from eddy covariance (EC) flux towers (e.g. a rainforest site in Bariri, Sulawesi; an oil palm site in Jambi, Sumatra). After validation, the project will proceed to parameterize land-use transformation system using remote sensing data and to simulate the impacts of historical LUCs on carbon, water and energy fluxes. Last but not least, the effects of future LUCs in Indonesia on the fluxes and carbon sequestration capacity will be investigated through scenario study. Historical land cover changes, especially oil palm coverage, are retrieved from Landsat or MODIS archival images. Oil palm concession boundaries are used to define and project future land use scenarios. Initial results include outputs from a single-point simulation for the Bariri rainforest site forced with locally measured meteorological data which already showed significant advantage over global forcing data in predicting net ecosystem exchange and latent and sensible heat fluxes. Modeled fluxes are being compared with EC flux observations and with Mixfor-SVAT model outputs from another project at the same site. In the next few months, focus will be on sensitivity analyses of model parameters including PFT optical, morphological and physiological parameters that are necessary to configure the new oil palm PFT and represent rainforest to oil palm conversion. The new parameterization will contribute to the development of the CLM model and its implementation in the modelling of LUC effects in tropical regions will help understanding land-climate interactions.
NASA Astrophysics Data System (ADS)
Wulamu, A.; Fishman, J.; Maimaitiyiming, M.; Leitch, J. W.; Zoogman, P.; Liu, X.; Chance, K.; Marshall, B.
2015-12-01
Understanding the bi-directional reflectance function (BRDF) and spectral albedo of various land-cover types is critical for retrieval of trace gas measurements from planned geostationary satellites such as the Tropospheric Emissions: Monitoring of Pollution (TEMPO). Radiant energy, which will be measured by these instruments at the top of atmosphere (TOA) at unprecedented spectral resolution, is strongly influenced by how this energy is reflected by the underlying surface. Thus, it is critical that we understand this phenomenon at comparable wavelength resolution. As part of the NASA ESTO-funded Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) development project, we carried out synchronous field and airborne data collection campaigns in the St Louis Metro region in Summer 2014. We collected spectral reflectance data of various land cover types on the ground within hours of a GeoTASO overpass using a field-based hyperspectral spectroradiometer (model PSR3500 from Spectral Evolution). Field measurements collecting in-situ spectral albedo and bidirectional reflectance factors were also obtained in July and August of 2015. In this study, we present our preliminary findings from in-situ and airborne GeoTASO derived spectral albedo and BRDF characteristics of major land cover types at TEMPO spectral profiles, which are necessary for the accurate retrieval of tropospheric trace gases and aerosols. First, a spectral database of various targets (e.g., plants, soils, rocks, man-made objects and water) was developed using field measurements. Next, the GeoTASO airborne data were corrected using MODTRAN and field measurements to derive spectral albedo and BRDF. High spatial resolution land-cover types were extracted using satellite images (e.g., Landsat, WorldView, IKONOS, etc.) at resolutions from 2 m - 30 m. Lastly, spectral albedo/BRDFs corresponding to various land cover types were analyzed using both field and GeoTASO measurements.
Thermoelectric properties of an ultra-thin topological insulator.
Islam, S K Firoz; Ghosh, T K
2014-04-23
Thermoelectric coefficients of an ultra-thin topological insulator are presented here. The hybridization between top and bottom surface states of a topological insulator plays a significant role. In the absence of a magnetic field, the thermopower increases and thermal conductivity decreases with an increase in the hybridization energy. In the presence of a magnetic field perpendicular to the ultra-thin topological insulator, thermoelectric coefficients exhibit quantum oscillations with inverse magnetic field, whose frequency is strongly modified by the Zeeman energy and whose phase factor is governed by the product of the Landé g-factor and the hybridization energy. In addition to the numerical results, the low-temperature approximate analytical results for the thermoelectric coefficients are also provided. It is also observed that for a given magnetic field these transport coefficients oscillate with hybridization energy, at a frequency that depends on the Landé g-factor.
Massonnet, D.; Holzer, T.; Vadon, H.
1997-01-01
Interferometric combination of pairs of synthetic aperture radar (SAR) images acquired by the ERS-1 satellite maps the deformation field associated with the activity of the East Mesa geothermal plant, located in southern California. SAR interferometry is applied to this flat area without the need of a digital terrain model. Several combinations are used to ascertain the nature of the phenomenon. Short term interferograms reveal surface phase changes on agricultural fields similar to what had been observed previously with SEASAT radar data. Long term (2 years) interferograms allow the study of land subsidence and improve prior knowledge of the displacement field, and agree with existing, sparse levelling data. This example illustrates the power of the interferometric technique for deriving accurate industrial intelligence as well as its potential for legal action, in cases involving environmental damages. Copyright 1997 by the American Geophysical Union.
Land motion due to 20th century mass balance of the Greenland Ice Sheet
NASA Astrophysics Data System (ADS)
Kjeldsen, K. K.; Khan, S. A.
2017-12-01
Quantifying the contribution from ice sheets and glaciers to past sea level change is of great value for understanding sea level projections into the 21st century. However, quantifying and understanding past changes are equally important, in particular understanding the impact in the near-field where the signal is highest. We assess the impact of 20th century mass balance of the Greenland Ice Sheet on land motion using results from Kjeldsen et al, 2015. These results suggest that the ice sheet on average lost a minimum of 75 Gt/yr, but also show that the mass balance was highly spatial- and temporal variable, and moreover that on a centennial time scale changes were driven by a decreasing surface mass balance. Based on preliminary results we discuss land motion during the 20th century due to mass balance changes and the driving components surface mass balance and ice dynamics.
2017-01-21
What would it be like to actually land on Pluto? This image is one of more than 100 images taken by NASA's New Horizons spacecraft over six weeks of approach and close flyby in the summer of 2015. A video offers a trip down onto the surface of Pluto -- starting with a distant view of Pluto and its largest moon, Charon -- and leading up to an eventual ride in for a "landing" on the shoreline of Pluto's informally named Sputnik Planitia. After a 9.5-year voyage covering more than three billion miles, New Horizons flew through the Pluto system on July 14, 2015, coming within 7,800 miles (12,500 kilometers) of Pluto. Carrying powerful telescopic cameras that could spot features smaller than a football field, New Horizons sent back hundreds of images of Pluto and its moons that show how dynamic and fascinating their surfaces are. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA11709
Crane, Michael; Yates, Kimberly; Clark, Robert; Gesch, Dean; Hess, Kurt; Koehmstedt, John; Milbert, Dennis; Parker, Bruce; Sechrist, Dan; Tilley, Janet; Wilson, Robert
2001-01-01
Tampa Bay and its environs have experienced phenomenal urban growth and significant changes in land cover and land-use practices over the past 50 years. This trend is expected to continue, with the impact of human activity broadening geographically and intensifying throughout the region.One of the immediate impacts of urban growth is the creation of additional impervious surfaces, which in turn, generate increased urban runoff that contributes to higher levels of nutrient loading in water bodies throughout the area.To better understand these and other anthropogenic affects on the ecology of the natural environment of the region, this component of the Tampa Bay Pilot Study took a broad basin-wide view. This regional view was intended to provide geographic and temporal context for the smaller intensely studied sample field site locations within the estuarine environment.
Deterioration of soil fertility by land use changes in South Sumatra, Indonesia: from 1970 to 1990
NASA Astrophysics Data System (ADS)
Lumbanraja, Jamalam; Syam, Tamaluddin; Nishide, Hiroyo; Kabul Mahi, Ali; Utomo, Muhajir; Sarno; Kimura, Makoto
1998-10-01
We monitored the land use changes in a hilly area of West Lampung, South Sumatra, Indonesia, from 1970 to 1990. The main data sources were the land use maps produced in 1970, 1978, 1984 and 1990 covering the area of 27 km×27 km. Transmigration and the resultant effect of increased population were the major driving forces in land use changes. Fifty-seven per cent of the study area was covered with primary forests in 1970, but only 13% in 1990. Areas under plantations, which were absent in 1970, increased to 60% in 1990. In addition, the change from monoculture plantations (mostly coffee plantation) to mixed plantations was noticeable from 1984 to 1990. Total upland areas including upland areas under shifting cultivation and upland fields with crops and vegetables decreased from 21% in 1970 to 0·1% in 1990. Soil chemical properties (total organic C, total N, available P, total P, exchangeable cations, cation exchangeable capacity (CEC), etc.) were analysed for lands under different land use forms after deforestation in the study area. Soil samples (surface layers, 0-20 cm, and subsurface layers, 20-40 cm) were collected from three different locations, each comprised of four different land use systems: i.e. primary forests, secondary forests, coffee plantations and cultivated lands. The contents of total organic C, total N, available P, total P, exchangeable cations and CEC decreased significantly with land use change from primary forests to the other land use forms. Cultivated lands exhibited the lowest values. Although less remarkable than in the surface layers, the amounts of total organic C, total N, total P, exchangeable cations and CEC were also decreased by forest clearing in the subsurface layers.Based on the land use changes from 1978 in the study area and the deterioration of soil chemical properties by forest clearing, total decreases in the amounts of nutrients in the surface and subsurface layers were estimated. The land use changes were estimated to have decreased the total amounts of total organic C, total N, available P, total P, exchangeable cations and CEC by 2-9% in 1984 and by 2-15% in 1990 in the surface layers, and by 1-6%% in 1984 and by 2-9% in 1990 in the subsurface layers from the levels in 1978, respectively.
Bowers, Robert M; McLetchie, Shawna; Knight, Rob; Fierer, Noah
2011-01-01
Although bacteria are ubiquitous in the near-surface atmosphere and they can have important effects on human health, airborne bacteria have received relatively little attention and their spatial dynamics remain poorly understood. Owing to differences in meteorological conditions and the potential sources of airborne bacteria, we would expect the atmosphere over different land-use types to harbor distinct bacterial communities. To test this hypothesis, we sampled the near-surface atmosphere above three distinct land-use types (agricultural fields, suburban areas and forests) across northern Colorado, USA, sampling five sites per land-use type. Microbial abundances were stable across land-use types, with ∼105–106 bacterial cells per m3 of air, but the concentrations of biological ice nuclei, determined using a droplet freezing assay, were on average two and eight times higher in samples from agricultural areas than in the other two land-use types. Likewise, the composition of the airborne bacterial communities, assessed via bar-coded pyrosequencing, was significantly related to land-use type and these differences were likely driven by shifts in the sources of bacteria to the atmosphere across the land-uses, not local meteorological conditions. A meta-analysis of previously published data shows that atmospheric bacterial communities differ from those in potential source environments (leaf surfaces and soils), and we demonstrate that we may be able to use this information to determine the relative inputs of bacteria from these source environments to the atmosphere. This work furthers our understanding of bacterial diversity in the atmosphere, the terrestrial controls on this diversity and potential approaches for source tracking of airborne bacteria. PMID:21048802
Noah-MP-Crop: Introducing dynamic crop growth in the Noah-MP land surface model
NASA Astrophysics Data System (ADS)
Liu, Xing; Chen, Fei; Barlage, Michael; Zhou, Guangsheng; Niyogi, Dev
2016-12-01
Croplands are important in land-atmosphere interactions and in the modification of local and regional weather and climate; however, they are poorly represented in the current version of the coupled Weather Research and Forecasting/Noah with multiparameterization (Noah-MP) land surface modeling system. This study introduced dynamic corn (Zea mays) and soybean (Glycine max) growth simulations and field management (e.g., planting date) into Noah-MP and evaluated the enhanced model (Noah-MP-Crop) at field scales using crop biomass data sets, surface heat fluxes, and soil moisture observations. Compared to the generic dynamic vegetation and prescribed-leaf area index (LAI)-driven methods in Noah-MP, the Noah-MP-Crop showed improved performance in simulating leaf area index (LAI) and crop biomass. This model is able to capture the seasonal and annual variability of LAI and to differentiate corn and soybean in peak values of LAI as well as the length of growing seasons. Improved simulations of crop phenology in Noah-MP-Crop led to better surface heat flux simulations, especially in the early period of growing season where current Noah-MP significantly overestimated LAI. The addition of crop yields as model outputs expand the application of Noah-MP-Crop to regional agriculture studies. There are limitations in the use of current growing degree days (GDD) criteria to predict growth stages, and it is necessary to develop a new method that combines GDD with other environmental factors, to more accurately define crop growth stages. The capability introduced in Noah-MP allows further crop-related studies and development.
New Mexico Tech landmine, UXO, IED detection sensor test facility: measurements in real field soils
NASA Astrophysics Data System (ADS)
Hendrickx, Jan M. H.; Alkov, Nicole; Hong, Sung-ho; Van Dam, Remke L.; Kleissl, Jan; Shannon, Heather; Meason, John; Borchers, Brian; Harmon, Russell S.
2006-05-01
Modeling studies and experimental work have demonstrated that the dynamic behavior of soil physical properties has a significant effect on most sensors for the detection of buried land mines. An outdoor test site has been constructed allowing full control over soil water content and continuous monitoring of important soil properties and environmental conditions. Time domain reflectometry sensors and thermistors measure soil water1 content and temperature, respectively, at different depths above and below the land mines as well as in homogeneous soil away from the land mines. During the two-year operation of the test-site, the soils have evolved to reflect real field soil conditions. This paper compares visual observations as well as ground-penetrating radar and thermal infrared measurements at this site taken immediately after construction in early 2004 with measurements from early 2006. The visual observations reveal that the 2006 soil surfaces exhibit a much higher spatial variability due to the development of mini-reliefs, "loose" and "connected" soil crusts, cracks in clay soils, and vegetation. Evidence is presented that the increased variability of soil surface characteristics leads to a higher natural spatial variability of soil surface temperatures and, thus, to a lower probability to detect landmines using thermal imagery. No evidence was found that the soil surface changes affect the GPR signatures of landmines under the soil conditions encountered in this study. The New Mexico Tech outdoor Landmine Detection Sensor Test Facility is easily accessible and anyone interested is welcome to use it for sensor testing.
MISR Level 3 Land Surface and Aerosol Versioning
Atmospheric Science Data Center
2016-11-04
... in the Level 2 product can frequently occur over snow/ice fields due to low spatial contrast and also as a consequence of inadequate ... Many such blunders have been observed over Greenland and Antarctica. Therefore, these two geographic areas are currently being excluded ...
GLORI: A GNSS-R Dual Polarization Airborne Instrument for Land Surface Monitoring
Motte, Erwan; Zribi, Mehrez; Fanise, Pascal; Egido, Alejandro; Darrozes, José; Al-Yaari, Amen; Baghdadi, Nicolas; Baup, Frédéric; Dayau, Sylvia; Fieuzal, Remy; Frison, Pierre-Louis; Guyon, Dominique; Wigneron, Jean-Pierre
2016-01-01
Global Navigation Satellite System-Reflectometry (GNSS-R) has emerged as a remote sensing tool, which is complementary to traditional monostatic radars, for the retrieval of geophysical parameters related to surface properties. In the present paper, we describe a new polarimetric GNSS-R system, referred to as the GLObal navigation satellite system Reflectometry Instrument (GLORI), dedicated to the study of land surfaces (soil moisture, vegetation water content, forest biomass) and inland water bodies. This system was installed as a permanent payload on a French ATR42 research aircraft, from which simultaneous measurements can be carried out using other instruments, when required. Following initial laboratory qualifications, two airborne campaigns involving nine flights were performed in 2014 and 2015 in the Southwest of France, over various types of land cover, including agricultural fields and forests. Some of these flights were made concurrently with in situ ground truth campaigns. Various preliminary applications for the characterisation of agricultural and forest areas are presented. Initial analysis of the data shows that the performance of the GLORI instrument is well within specifications, with a cross-polarization isolation better than −15 dB at all elevations above 45°, a relative polarimetric calibration accuracy better than 0.5 dB, and an apparent reflectivity sensitivity better than −30 dB, thus demonstrating its strong potential for the retrieval of land surface characteristics. PMID:27213393
NASA Astrophysics Data System (ADS)
AllahTavakoli, Yahya; Safari, Abdolreza; Vaníček, Petr
2016-12-01
This paper resurrects a version of Poisson's Partial Differential Equation (PDE) associated with the gravitational field at the Earth's surface and illustrates how the PDE possesses a capability to extract the mass density of Earth's topography from land-based gravity data. Herein, first we propound a theorem which mathematically introduces this version of Poisson's PDE adapted for the Earth's surface and then we use this PDE to develop a method of approximating the terrain mass density. Also, we carry out a real case study showing how the proposed approach is able to be applied to a set of land-based gravity data. In the case study, the method is summarized by an algorithm and applied to a set of gravity stations located along a part of the north coast of the Persian Gulf in the south of Iran. The results were numerically validated via rock-samplings as well as a geological map. Also, the method was compared with two conventional methods of mass density reduction. The numerical experiments indicate that the Poisson PDE at the Earth's surface has the capability to extract the mass density from land-based gravity data and is able to provide an alternative and somewhat more precise method of estimating the terrain mass density.
GLORI: A GNSS-R Dual Polarization Airborne Instrument for Land Surface Monitoring.
Motte, Erwan; Zribi, Mehrez; Fanise, Pascal; Egido, Alejandro; Darrozes, José; Al-Yaari, Amen; Baghdadi, Nicolas; Baup, Frédéric; Dayau, Sylvia; Fieuzal, Remy; Frison, Pierre-Louis; Guyon, Dominique; Wigneron, Jean-Pierre
2016-05-20
Global Navigation Satellite System-Reflectometry (GNSS-R) has emerged as a remote sensing tool, which is complementary to traditional monostatic radars, for the retrieval of geophysical parameters related to surface properties. In the present paper, we describe a new polarimetric GNSS-R system, referred to as the GLObal navigation satellite system Reflectometry Instrument (GLORI), dedicated to the study of land surfaces (soil moisture, vegetation water content, forest biomass) and inland water bodies. This system was installed as a permanent payload on a French ATR42 research aircraft, from which simultaneous measurements can be carried out using other instruments, when required. Following initial laboratory qualifications, two airborne campaigns involving nine flights were performed in 2014 and 2015 in the Southwest of France, over various types of land cover, including agricultural fields and forests. Some of these flights were made concurrently with in situ ground truth campaigns. Various preliminary applications for the characterisation of agricultural and forest areas are presented. Initial analysis of the data shows that the performance of the GLORI instrument is well within specifications, with a cross-polarization isolation better than -15 dB at all elevations above 45°, a relative polarimetric calibration accuracy better than 0.5 dB, and an apparent reflectivity sensitivity better than -30 dB, thus demonstrating its strong potential for the retrieval of land surface characteristics.
NASA Astrophysics Data System (ADS)
Mishra, V.; Cruise, J. F.; Mecikalski, J. R.
2015-12-01
Developing accurate vertical soil moisture profiles with minimum input requirements is important to agricultural as well as land surface modeling. Earlier studies show that the principle of maximum entropy (POME) can be utilized to develop vertical soil moisture profiles with accuracy (MAE of about 1% for a monotonically dry profile; nearly 2% for monotonically wet profiles and 3.8% for mixed profiles) with minimum constraints (surface, mean and bottom soil moisture contents). In this study, the constraints for the vertical soil moisture profiles were obtained from remotely sensed data. Low resolution (25 km) MW soil moisture estimates (AMSR-E) were downscaled to 4 km using a soil evaporation efficiency index based disaggregation approach. The downscaled MW soil moisture estimates served as a surface boundary condition, while 4 km resolution TIR based Atmospheric Land Exchange Inverse (ALEXI) estimates provided the required mean root-zone soil moisture content. Bottom soil moisture content is assumed to be a soil dependent constant. Mulit-year (2002-2011) gridded profiles were developed for the southeastern United States using the POME method. The soil moisture profiles were compared to those generated in land surface models (Land Information System (LIS) and an agricultural model DSSAT) along with available NRCS SCAN sites in the study region. The end product, spatial soil moisture profiles, can be assimilated into agricultural and hydrologic models in lieu of precipitation for data scarce regions.Developing accurate vertical soil moisture profiles with minimum input requirements is important to agricultural as well as land surface modeling. Previous studies have shown that the principle of maximum entropy (POME) can be utilized with minimal constraints to develop vertical soil moisture profiles with accuracy (MAE = 1% for monotonically dry profiles; MAE = 2% for monotonically wet profiles and MAE = 3.8% for mixed profiles) when compared to laboratory and field data. In this study, vertical soil moisture profiles were developed using the POME model to evaluate an irrigation schedule over a maze field in north central Alabama (USA). The model was validated using both field data and a physically based mathematical model. The results demonstrate that a simple two-constraint entropy model under the assumption of a uniform initial soil moisture distribution can simulate most soil moisture profiles within the field area for 6 different soil types. The results of the irrigation simulation demonstrated that the POME model produced a very efficient irrigation strategy with loss of about 1.9% of the total applied irrigation water. However, areas of fine-textured soil (i.e. silty clay) resulted in plant stress of nearly 30% of the available moisture content due to insufficient water supply on the last day of the drying phase of the irrigation cycle. Overall, the POME approach showed promise as a general strategy to guide irrigation in humid environments, with minimum input requirements.
2014-03-11
CAPE CANAVERAL, Fla. - The Project Morpheus prototype lander touches down in the automated landing and hazard avoidance technology, or ALHAT, hazard field after completing its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Mike Chambers
Ke, Xin; Liang, Wenju; Yu, Wantai; Xie, Rongdong; Weng, Chaolian; Yang, Yiming; Yin, Wenying
2004-04-01
The data on the soil micro-arthropodes under four land utilization types (fallow, forest, upland field and paddy) in the Lower Reaches of Liaohe River Plain were collected in a period from October 2000 to October 2001. Using the community parameters of population density, group richness, diversity index and evenness, the community structure and its seasonal changes were described. There were 12 groups of soil micro-arthropodes in this region, and of the groups, Collembola and Acarina were dominant, and Diptera, Coleoptera and Hymenoptera were often seen in fallow, forest and upland field, while Collembola, Acarina and Diptera were dominant in paddy. Both land utilization and seasonal change influenced the population density, group richness and diversity index of soil micro-arthropodes. The vertical distribution in both density and group number of arthropods in soil was in the order of surface > middle > bottom.
Assessing Northern Hemisphere Land-Atmosphere Hotspots Using Dynamical Adjustment
NASA Astrophysics Data System (ADS)
Merrifield, Anna; Lehner, Flavio; Deser, Clara; Xie, Shang-Ping
2017-04-01
Understanding the influence of soil moisture on surface air temperature (SAT) is made more challenging by large-scale, internal atmospheric variability present in the midlatitude summer atmosphere. In this study, dynamical adjustment is used to characterize and remove summer SAT variability associated with large-scale circulation patterns in the Community Earth System Model large ensemble (CESM-LE). The adjustment is performed over North America and Europe with two different circulation indicators: sea level pressure (SLP) and 500mb height (Z500). The removal of dynamical "noise" leaves residual SAT variability in the central U.S. and Mediterranean regions identified as hotspots of land-atmosphere interaction (e.g. Koster et al. 2004, Seneviratne et al. 2006). The residual SAT variability "signal" is not clearly related to modes of sea surface temperature (SST) variability, but is related to local soil moisture, evaporative fraction, and radiation availability. These local relationships suggest that residual SAT variability is representative of the aggregate land surface signal. SLP dynamical adjustment removes ˜15% more variability in the central U.S. hotspot region than Z500 dynamical adjustment. Similar amounts of variability are removed by SLP and Z500 in the Mediterranean region. Differences in SLP and Z500 signal magnitude in the central U.S. are likely due to the modification of SLP by local land surface conditions, while the proximity of European hotspots to the Mediterranean sea mitigates the land surface influence. Variations in the Z500 field more closely resemble large-scale midlatitude circulation patterns and therefore Z500 may be a more suitable circulation indicator for summer dynamical adjustment. Changes in the residual SAT variability signal under increased greenhouse gas forcing will also be explored.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Henderson-Sellers, A.
Land-surface schemes developed for incorporation into global climate models include parameterizations that are not yet fully validated and depend upon the specification of a large (20-50) number of ecological and soil parameters, the values of which are not yet well known. There are two methods of investigating the sensitivity of a land-surface scheme to prescribed values: simple one-at-a-time changes or factorial experiments. Factorial experiments offer information about interactions between parameters and are thus a more powerful tool. Here the results of a suite of factorial experiments are reported. These are designed (i) to illustrate the usefulness of this methodology andmore » (ii) to identify factors important to the performance of complex land-surface schemes. The Biosphere-Atmosphere Transfer Scheme (BATS) is used and its sensitivity is considered (a) to prescribed ecological and soil parameters and (b) to atmospheric forcing used in the off-line tests undertaken. Results indicate that the most important atmospheric forcings are mean monthly temperature and the interaction between mean monthly temperature and total monthly precipitation, although fractional cloudiness and other parameters are also important. The most important ecological parameters are vegetation roughness length, soil porosity, and a factor describing the sensitivity of the stomatal resistance of vegetation to the amount of photosynthetically active solar radiation and, to a lesser extent, soil and vegetation albedos. Two-factor interactions including vegetation roughness length are more important than many of the 23 specified single factors. The results of factorial sensitivity experiments such as these could form the basis for intercomparison of land-surface parameterization schemes and for field experiments and satellite-based observation programs aimed at improving evaluation of important parameters.« less
NASA Astrophysics Data System (ADS)
Zhang, X.; Yu, Y.; Liu, L.
2015-12-01
Land surface phenology quantifies seasonal dynamics of vegetation properties including the timing and magnitude of vegetation greenness from satellite observations. Over the last decade, historical time series of AVHRR and MODIS data has been used to characterize the seasonal and interannual variation in terrestrial ecosystems and their responses to a changing and variable climate. The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on board the operational JPSS satellites provides land surface observations in a timely fashion, which has the capability to monitor phenological development in near real time. This capability is particularly important for assisting agriculture, natural resource management, and land modeling for weather prediction systems. Here we introduce a system to monitor in real time and forecast in the short term phenological development based on daily VIIRS observations available with a one-day latency. The system integrates a climatological land surface phenology from long-term MODIS data and available VIIRS observations to simulate a set of potential temporal trajectories of greenness development at a given time and pixel. The greenness trajectories, which are qualified using daily two-band Enhanced Vegetation Index (EVI2), are applied to identify spring green leaf development and autumn color foliage status in real time and to predict the occurrence of future phenological events. This system currently monitors vegetation development across the North America every three days and makes prediction to 10 days ahead. We further introduce the applications of near real time spring green leaf and fall color foliage. Specifically, this system is used for tracing the crop progress across the United States, guiding the field observations in US National Phenology Network, servicing tourists for the observation of color fall foliage, and parameterizing seasonal surface physical conditions for numerical weather prediction models.
2014-03-05
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander touches down in the automated landing and hazard avoidance technology, or ALHAT, hazard field after completing its sixth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Frankie Martin
Pumping-induced stress and strain in aquifer systems in Wuxi, China
NASA Astrophysics Data System (ADS)
Zhang, Yun; Yu, Jun; Gong, Xulong; Wu, Jichun; Wang, Zhecheng
2018-05-01
Excessive groundwater withdrawal from an aquifer system leads to three-dimensional displacement, causing changes in the states of stress and strain. Often, land subsidence and sometimes earth fissures ensue. Field investigation indicates that land subsidence and earth fissures in Wuxi, a city in eastern China, are mainly due to excessive groundwater withdrawal, and that they are temporally and spatially related to groundwater pumping. Groundwater withdrawal may cause tensile strain to develop in aquifer systems, but tensile strain does not definitely mean tensile stress. Where earth fissures are concerned, the stress state should be adopted in numerical simulations instead of the strain state and displacement. The numerical simulation undertaken for the Wuxi area shows that the zone of tensile strain occupies a large area on the ground surface; nevertheless, the zone of tensile stress is very limited. The zone of tensile stress often occurs near the ground surface, beneath which the depth to the bedrock surface is relatively small and has considerable variability. Earth fissures often initiate near the ground surface where tensile stress occurs. Tensile stress and earth fissures rarely develop at the centers of land subsidence bowls, where compressive stress is dominant.
NASA Astrophysics Data System (ADS)
Li, Z.; Shiklomanov, N. I.
2015-12-01
Urbanization and industrial development have significant impacts on arctic climate that in turn controls settlement patterns and socio-economic processes. In this study we have analyzed the anthropogenic influences on regional land surface temperature of Lower Yenisei River Region of the Russia Arctic. The study area covers two consecutive Landsat scenes and includes three major cities: Norilsk, Igarka and Dudingka. Norilsk industrial region is the largest producer of nickel and palladium in the world, and Igarka and Dudingka are important ports for shipping. We constructed a spatio-temporal interpolated temperature model by including 1km MODIS LST, field-measured climate, Modern Era Retrospective-analysis for Research and Applications (MERRA), DEM, Landsat NDVI and Landsat Land Cover. Those fore-mentioned spatial data have various resolution and coverage in both time and space. We analyzed their relationships and created a monthly spatio-temporal interpolated surface temperature model at 1km resolution from 1980 to 2010. The temperature model then was used to examine the characteristic seasonal LST signatures, related to several representative assemblages of Arctic urban and industrial infrastructure in order to quantify anthropogenic influence on regional surface temperature.
NASA Astrophysics Data System (ADS)
Separovic, Leo; Husain, Syed Zahid; Yu, Wei
2015-09-01
Internal variability (IV) in dynamical downscaling with limited-area models (LAMs) represents a source of error inherent to the downscaled fields, which originates from the sensitive dependence of the models to arbitrarily small modifications. If IV is large it may impose the need for probabilistic verification of the downscaled information. Atmospheric spectral nudging (ASN) can reduce IV in LAMs as it constrains the large-scale components of LAM fields in the interior of the computational domain and thus prevents any considerable penetration of sensitively dependent deviations into the range of large scales. Using initial condition ensembles, the present study quantifies the impact of ASN on IV in LAM simulations in the range of fine scales that are not controlled by spectral nudging. Four simulation configurations that all include strong ASN but differ in the nudging settings are considered. In the fifth configuration, grid nudging of land surface variables toward high-resolution surface analyses is applied. The results show that the IV at scales larger than 300 km can be suppressed by selecting an appropriate ASN setup. At scales between 300 and 30 km, however, in all configurations, the hourly near-surface temperature, humidity, and winds are only partly reproducible. Nudging the land surface variables is found to have the potential to significantly reduce IV, particularly for fine-scale temperature and humidity. On the other hand, hourly precipitation accumulations at these scales are generally irreproducible in all configurations, and probabilistic approach to downscaling is therefore recommended.
NASA Technical Reports Server (NTRS)
Peters-Lidard, Christa D.
2011-01-01
The Land Information System (LIS; http://lis.gsfc.nasa.gov) is a flexible land surface modeling framework that has been developed with the goal of integrating satellite-and ground-based observational data products and advanced land surface modeling techniques to produce optimal fields of land surface states and fluxes. As such, LIS represents a step towards the next generation land component of an integrated Earth system model. In recognition of LIS object-oriented software design, use and impact in the land surface and hydrometeorological modeling community, the LIS software was selected as a co-winner of NASA?s 2005 Software of the Year award.LIS facilitates the integration of observations from Earth-observing systems and predictions and forecasts from Earth System and Earth science models into the decision-making processes of partnering agency and national organizations. Due to its flexible software design, LIS can serve both as a Problem Solving Environment (PSE) for hydrologic research to enable accurate global water and energy cycle predictions, and as a Decision Support System (DSS) to generate useful information for application areas including disaster management, water resources management, agricultural management, numerical weather prediction, air quality and military mobility assessment. LIS has e volved from two earlier efforts -- North American Land Data Assimilation System (NLDAS) and Global Land Data Assimilation System (GLDAS) that focused primarily on improving numerical weather prediction skills by improving the characterization of the land surface conditions. Both of GLDAS and NLDAS now use specific configurations of the LIS software in their current implementations.In addition, LIS was recently transitioned into operations at the US Air Force Weather Agency (AFWA) to ultimately replace their Agricultural Meteorology (AGRMET) system, and is also used routinely by NOAA's National Centers for Environmental Prediction (NCEP)/Environmental Modeling Center (EMC) for their land data assimilation systems to support weather and climate modeling. LIS not only consolidates the capabilities of these two systems, but also enables a much larger variety of configurations with respect to horizontal spatial resolution, input datasets and choice of land surface model through "plugins". LIS has been coupled to the Weather Research and Forecasting (WRF) model to support studies of land-atmosphere coupling be enabling ensembles of land surface states to be tested against multiple representations of the atmospheric boundary layer. LIS has also been demonstrated for parameter estimation, who showed that the use of sequential remotely sensed soil moisture products can be used to derive soil hydraulic and texture properties given a sufficient dynamic range in the soil moisture retrievals and accurate precipitation inputs.LIS has also recently been demonstrated for multi-model data assimilation using an Ensemble Kalman Filter for sequential assimilation of soil moisture, snow, and temperature.Ongoing work has demonstrated the value of bias correction as part of the filter, and also that of joint calibration and assimilation.Examples and case studies demonstrating the capabilities and impacts of LIS for hydrometeorological modeling, assimilation and parameter estimation will be presented as advancements towards the next generation of integrated observation and modeling systems
Kanematsu, Masakazu; Shimizu, Yoshihisa; Sato, Keisuke; Kim, Suejin; Suzuki, Tasuma; Park, Baeksoo; Saino, Reiko; Nakamura, Masafumi
2009-06-15
Significant dioxins accumulations in Japanese forests and paddy fields have been observed, and surface soil runoff caused by rainfall and irrigation (i.e., soil puddling in paddy fields) results in dioxins input into the aquatic environment. An extensive investigation into the origins and transport of aquatic dioxins in the Yasu watershed, Japan was conducted considering surface soil contamination level, land use, and type of soil runoff event (i.e., irrigation runoff [IR], rainfall runoff [RR], and base flow [BF]). Combined use of the chemically activated luciferase expression (CALUX) assay together with high-resolution gas chromatography and high-resolution mass spectrometry (HRGC/HRMS) efficiently enabled this study, so that origins, transport, and dynamic movement of aquatic dioxins in the watershed were revealed. The particulate organic carbon normalized particulate-dioxins WHO-toxic equivalent (TEQ) concentration predicted by the CALUX assay (Spar) was found to be a convenient molecular marker to indicate origins of aquatic dioxins and clearly reflect surface soil contamination level, land use, and soil runoff events. Using experimental results and theoretical modeling, the annual loading amount of dioxins at the middle reach of the river was estimated to be 0.458 mg WHO-TEQ in 2004. More than 96.6% of the annual loading amount was attributed to RR and derived almost evenly from forest and paddy fields at the study location. Because the annual loading amount at the middle reach is less than 0.5% of the total dioxins accumulated in the upper basin, dioxins runoff from the Japanese watershed will continue. This study shows that the combined use of the bioassay with HRGC/HRMS can provide new insights into dioxins transport and fate in the environment.
Classification of forest land attributes using multi-source remotely sensed data
NASA Astrophysics Data System (ADS)
Pippuri, Inka; Suvanto, Aki; Maltamo, Matti; Korhonen, Kari T.; Pitkänen, Juho; Packalen, Petteri
2016-02-01
The aim of the study was to (1) examine the classification of forest land using airborne laser scanning (ALS) data, satellite images and sample plots of the Finnish National Forest Inventory (NFI) as training data and to (2) identify best performing metrics for classifying forest land attributes. Six different schemes of forest land classification were studied: land use/land cover (LU/LC) classification using both national classes and FAO (Food and Agricultural Organization of the United Nations) classes, main type, site type, peat land type and drainage status. Special interest was to test different ALS-based surface metrics in classification of forest land attributes. Field data consisted of 828 NFI plots collected in 2008-2012 in southern Finland and remotely sensed data was from summer 2010. Multinomial logistic regression was used as the classification method. Classification of LU/LC classes were highly accurate (kappa-values 0.90 and 0.91) but also the classification of site type, peat land type and drainage status succeeded moderately well (kappa-values 0.51, 0.69 and 0.52). ALS-based surface metrics were found to be the most important predictor variables in classification of LU/LC class, main type and drainage status. In best classification models of forest site types both spectral metrics from satellite data and point cloud metrics from ALS were used. In turn, in the classification of peat land types ALS point cloud metrics played the most important role. Results indicated that the prediction of site type and forest land category could be incorporated into stand level forest management inventory system in Finland.
Morpheus 1C preps & post launch activities
2014-03-11
CAPE CANAVERAL, Fla. - An engineer checks the Project Morpheus prototype lander after it landed in the automated landing and hazard avoidance technology, or ALHAT, hazard field, completing its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
Underwater MASW to evaluate stiffness of water-bottom sediments
Park, C.B.; Miller, R.D.; Xia, J.; Ivanov, J.; Sonnichsen, G.V.; Hunter, J.A.; Good, R.L.; Burns, R.A.; Christian, H.
2005-01-01
The multichannel analysis of surface waves (MASW) is initially intended as a land survey method to investigate the near-surface materials for their elastic properties. The acquired data are first analyzed for dispersion characteristics and, from these the shear-wave velocity is estimated using an inversion technique. Land applications show the potential of the MASW method to map 2D bedrock surface, zones of low strength, Poisson's ratio, voids, as well as to generate shear-wave profiles for various othe geotechnical problems. An overview is given of several underwater applications of the MASW method to characterize stiffness distribution of water-bottom sediments. The first application details the survey under shallow-water (1-6 m) in the Fraser River (Canada). The second application is an innovative experimental marine seismic survey in the North Atlantic Ocean near oil fields in Grand Bank offshore Newfoundland.
Monitoring cover crops using radar remote sensing in southern Ontario, Canada
NASA Astrophysics Data System (ADS)
Shang, J.; Huang, X.; Liu, J.; Wang, J.
2016-12-01
Information on agricultural land surface conditions is important for developing best land management practices to maintain the overall health of the fields. The climate condition supports one harvest per year for the majority of the field crops in Canada, with a relative short growing season between May and September. During the non-growing-season months (October to the following April), many fields are traditionally left bare. In more recent year, there has been an increased interest in planting cover crops. Benefits of cover crops include boosting soil organic matters, preventing soil from erosion, retaining soil moisture, and reducing surface runoff hence protecting water quality. Optical remote sensing technology has been exploited for monitoring cover crops. However limitations inherent to optical sensors such as cloud interference and signal saturation (when leaf area index is above 2.5) impeded its operational application. Radar remote sensing on the other hand is not hindered by unfavorable weather conditions, and the signal continues to be sensitive to crop growth beyond the saturation point of optical sensors. It offers a viable means for capturing timely information on field surface conditions (with or without crop cover) or crop development status. This research investigated the potential of using multi-temporal RADARSAT-2 C-band synthetic aperture radar (SAR) data collected in 2015 over multiple fields of winter wheat, corn and soybean crops in southern Ontario, Canada, to retrieve information on the presence of cover crops and their growth status. Encouraging results have been obtained. This presentation will report the methodology developed and the results obtained.
First and Higher Order Effects on Zero Order Radiative Transfer Model
NASA Astrophysics Data System (ADS)
Neelam, M.; Mohanty, B.
2014-12-01
Microwave radiative transfer model are valuable tool in understanding the complex land surface interactions. Past literature has largely focused on local sensitivity analysis for factor priotization and ignoring the interactions between the variables and uncertainties around them. Since land surface interactions are largely nonlinear, there always exist uncertainties, heterogeneities and interactions thus it is important to quantify them to draw accurate conclusions. In this effort, we used global sensitivity analysis to address the issues of variable uncertainty, higher order interactions, factor priotization and factor fixing for zero-order radiative transfer (ZRT) model. With the to-be-launched Soil Moisture Active Passive (SMAP) mission of NASA, it is very important to have a complete understanding of ZRT for soil moisture retrieval to direct future research and cal/val field campaigns. This is a first attempt to use GSA technique to quantify first order and higher order effects on brightness temperature from ZRT model. Our analyses reflect conditions observed during the growing agricultural season for corn and soybeans in two different regions in - Iowa, U.S.A and Winnipeg, Canada. We found that for corn fields in Iowa, there exist significant second order interactions between soil moisture, surface roughness parameters (RMS height and correlation length) and vegetation parameters (vegetation water content, structure and scattering albedo), whereas in Winnipeg, second order interactions are mainly due to soil moisture and vegetation parameters. But for soybean fields in both Iowa and Winnipeg, we found significant interactions only to exist between soil moisture and surface roughness parameters.
NASA Astrophysics Data System (ADS)
Akim, E. L.; Ruzskiy, E. G.; Shishov, V. A.; Stepaniants, V. A.; Tuchin, A. G.
The main purpose of the Federal space program «Phobos-grunt» project is to deliver samples of a ground of Mars's natural satellite Phobos on Earth. Mission is planned to begin at the start window of 2009 year and to finish at 2011 year. The work is devoted to problems connected with development of the Phobos landing scheme. The major factors, the landing strategy is formed on, are the tasks connected with orbital mechanics, restrictions obliged by the space craft (SC) onboard systems, inexact knowledge of the Phobos's kinematics parameters, its hypsometry and gravity field.
NASA Astrophysics Data System (ADS)
Lifton, N. A.; Newall, J. C.; Fredin, O.; Glasser, N. F.; Fabel, D.; Rogozhina, I.; Bernales, J.; Prange, M.; Sams, S.; Eisen, O.; Hättestrand, C.; Harbor, J.; Stroeven, A. P.
2017-12-01
Numerical ice sheet models constrained by theory and refined by comparisons with observational data are a central component of work to address the interactions between the cryosphere and changing climate, at a wide range of scales. Such models are tested and refined by comparing model predictions of past ice geometries with field-based reconstructions from geological, geomorphological, and ice core data. However, on the East Antarctic Ice sheet, there are few empirical data with which to reconstruct changes in ice sheet geometry in the Dronning Maud Land (DML) region. In addition, there is poor control on the regional climate history of the ice sheet margin, because ice core locations, where detailed reconstructions of climate history exist, are located on high inland domes. This leaves numerical models of regional glaciation history in this near-coastal area largely unconstrained. MAGIC-DML is an ongoing Swedish-US-Norwegian-German-UK collaboration with a focus on improving ice sheet models by combining advances in numerical modeling with filling critical data gaps that exist in our knowledge of the timing and pattern of ice surface changes on the western Dronning Maud Land margin. A combination of geomorphological mapping using remote sensing data, field investigations, cosmogenic nuclide surface exposure dating, and numerical ice-sheet modeling are being used in an iterative manner to produce a comprehensive reconstruction of the glacial history of western Dronning Maud Land. We will present an overview of the project, as well as field observations and preliminary in situ cosmogenic nuclide measurements from the 2016/17 expedition.
2014-04-30
CAPE CANAVERAL, Fla. – NASA's Project Morpheus prototype lander touches down on the autonomous landing and hazard avoidance technology, or ALHAT, field after lifting off on a free-flight test from a new launch pad at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The 98-second test began at 1:57 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending more than 800 feet at a peak speed of 36 mph. The vehicle, with its recently installed ALHAT sensors, surveyed the hazard field to determine safe landing sites. Morpheus then flew forward and downward covering approximately 1300 feet while performing a 78-foot divert to simulate a hazard avoidance maneuver. The lander descended and landed on a dedicated pad inside the ALHAT hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, which are green propellants. These new capabilities could be used in future efforts to deliver cargo to planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-04-30
CAPE CANAVERAL, Fla. – NASA's Project Morpheus prototype lander touches down on the autonomous landing and hazard avoidance technology, or ALHAT, field after lifting off on a free-flight test from a new launch pad at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The 98-second test began at 1:57 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending more than 800 feet at a peak speed of 36 mph. The vehicle, with its recently installed ALHAT sensors, surveyed the hazard field to determine safe landing sites. Morpheus then flew forward and downward covering approximately 1300 feet while performing a 78-foot divert to simulate a hazard avoidance maneuver. The lander descended and landed on a dedicated pad inside the ALHAT hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, which are green propellants. These new capabilities could be used in future efforts to deliver cargo to planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Frankie Martin
Land cover characterization and land surface parameterization research
Steyaert, Louis T.; Loveland, Thomas R.; Parton, William J.
1997-01-01
The understanding of land surface processes and their parameterization in atmospheric, hydrologic, and ecosystem models has been a dominant research theme over the past decade. For example, many studies have demonstrated the key role of land cover characteristics as controlling factors in determining land surface processes, such as the exchange of water, energy, carbon, and trace gases between the land surface and the lower atmosphere. The requirements for multiresolution land cover characteristics data to support coupled-systems modeling have also been well documented, including the need for data on land cover type, land use, and many seasonally variable land cover characteristics, such as albedo, leaf area index, canopy conductance, surface roughness, and net primary productivity. Recently, the developers of land data have worked more closely with the land surface process modelers in these efforts.
Osuri, K. K.; Nadimpalli, R.; Mohanty, U. C.; Chen, F.; Rajeevan, M.; Niyogi, D.
2017-01-01
The hypothesis that realistic land conditions such as soil moisture/soil temperature (SM/ST) can significantly improve the modeling of mesoscale deep convection is tested over the Indian monsoon region (IMR). A high resolution (3 km foot print) SM/ST dataset prepared from a land data assimilation system, as part of a national monsoon mission project, showed close agreement with observations. Experiments are conducted with (LDAS) and without (CNTL) initialization of SM/ST dataset. Results highlight the significance of realistic land surface conditions on numerical prediction of initiation, movement and timing of severe thunderstorms as compared to that currently being initialized by climatological fields in CNTL run. Realistic land conditions improved mass flux, convective updrafts and diabatic heating in the boundary layer that contributed to low level positive potential vorticity. The LDAS run reproduced reflectivity echoes and associated rainfall bands more efficiently. Improper representation of surface conditions in CNTL run limit the evolution boundary layer processes and thereby failed to simulate convection at right time and place. These findings thus provide strong support to the role land conditions play in impacting the deep convection over the IMR. These findings also have direct implications for improving heavy rain forecasting over the IMR, by developing realistic land conditions. PMID:28128293
Benchmarking NLDAS-2 Soil Moisture and Evapotranspiration to Separate Uncertainty Contributions
NASA Technical Reports Server (NTRS)
Nearing, Grey S.; Mocko, David M.; Peters-Lidard, Christa D.; Kumar, Sujay V.; Xia, Youlong
2016-01-01
Model benchmarking allows us to separate uncertainty in model predictions caused 1 by model inputs from uncertainty due to model structural error. We extend this method with a large-sample approach (using data from multiple field sites) to measure prediction uncertainty caused by errors in (i) forcing data, (ii) model parameters, and (iii) model structure, and use it to compare the efficiency of soil moisture state and evapotranspiration flux predictions made by the four land surface models in the North American Land Data Assimilation System Phase 2 (NLDAS-2). Parameters dominated uncertainty in soil moisture estimates and forcing data dominated uncertainty in evapotranspiration estimates; however, the models themselves used only a fraction of the information available to them. This means that there is significant potential to improve all three components of the NLDAS-2 system. In particular, continued work toward refining the parameter maps and look-up tables, the forcing data measurement and processing, and also the land surface models themselves, has potential to result in improved estimates of surface mass and energy balances.
Benchmarking NLDAS-2 Soil Moisture and Evapotranspiration to Separate Uncertainty Contributions
Nearing, Grey S.; Mocko, David M.; Peters-Lidard, Christa D.; Kumar, Sujay V.; Xia, Youlong
2018-01-01
Model benchmarking allows us to separate uncertainty in model predictions caused by model inputs from uncertainty due to model structural error. We extend this method with a “large-sample” approach (using data from multiple field sites) to measure prediction uncertainty caused by errors in (i) forcing data, (ii) model parameters, and (iii) model structure, and use it to compare the efficiency of soil moisture state and evapotranspiration flux predictions made by the four land surface models in the North American Land Data Assimilation System Phase 2 (NLDAS-2). Parameters dominated uncertainty in soil moisture estimates and forcing data dominated uncertainty in evapotranspiration estimates; however, the models themselves used only a fraction of the information available to them. This means that there is significant potential to improve all three components of the NLDAS-2 system. In particular, continued work toward refining the parameter maps and look-up tables, the forcing data measurement and processing, and also the land surface models themselves, has potential to result in improved estimates of surface mass and energy balances. PMID:29697706
Benchmarking NLDAS-2 Soil Moisture and Evapotranspiration to Separate Uncertainty Contributions.
Nearing, Grey S; Mocko, David M; Peters-Lidard, Christa D; Kumar, Sujay V; Xia, Youlong
2016-03-01
Model benchmarking allows us to separate uncertainty in model predictions caused by model inputs from uncertainty due to model structural error. We extend this method with a "large-sample" approach (using data from multiple field sites) to measure prediction uncertainty caused by errors in (i) forcing data, (ii) model parameters, and (iii) model structure, and use it to compare the efficiency of soil moisture state and evapotranspiration flux predictions made by the four land surface models in the North American Land Data Assimilation System Phase 2 (NLDAS-2). Parameters dominated uncertainty in soil moisture estimates and forcing data dominated uncertainty in evapotranspiration estimates; however, the models themselves used only a fraction of the information available to them. This means that there is significant potential to improve all three components of the NLDAS-2 system. In particular, continued work toward refining the parameter maps and look-up tables, the forcing data measurement and processing, and also the land surface models themselves, has potential to result in improved estimates of surface mass and energy balances.
USDA-ARS?s Scientific Manuscript database
Thermal infrared band imagery provides key information for detecting wild fires, mapping land surface energy fluxes and evapotranspiration, monitoring urban heat fluxes and drought monitoring. Thermal infrared (TIR) imagery at fine resolution is required for field scale applications. However, therma...
Measurements of lunar magnetic field interaction with the solar wind.
NASA Technical Reports Server (NTRS)
Dyal, P.; Parkin, C. W.; Snyder, C. W.; Clay, D. R.
1972-01-01
Study of the compression of the remanent lunar magnetic field by the solar wind, based on measurements of remanent magnetic fields at four Apollo landing sites and of the solar wind at two of these sites. Available data show that the remanent magnetic field at the lunar surface is compressed as much as 40% above its initial value by the solar wind, but the total remanent magnetic pressure is less than the stagnation pressure by a factor of six, implying that a local shock is not formed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kennedy, Joseph
1991-03-01
At the request of True Mid Pacific Geothermal, Archaeological Consultants of Hawaii, Inc. has conducted an inventory survey at the site of the proposed Kilauea Middle East Rift Zone (KMERZ), Well Site No.2, TMK: 1-2-10:3. The Principal Investigator was Joseph Kennedy M.A., assisted by Jacob Kaio, Field Supervisor and field crew Mark Borrello B.A., Michael O'Shaughnessy B.A., and Randy Adric. This report supercedes all previous reports submitted to the Historic Presentation Section of the Department of Land and Natural Resources. In addition to 100% surface coverage of the 400 x 400 foot well pad itself, 100% surface coverage of amore » substantial buffer zone was also completed. This buffer zone was established by the Department of Land and Natural Resources, Historic Preservation personnel and extends 1000 feet east and west of the well site and 500 feet north and south of the well site.« less
NASA Astrophysics Data System (ADS)
Park, G.; Gao, X.; Sorooshian, S.
2005-12-01
The atmospheric model is sensitive to the land surface interactions and its coupling with Land surface Models (LSMs) leads to a better ability to forecast weather under extreme climate conditions, such as droughts and floods (Atlas et al. 1993; Beljaars et al. 1996). However, it is still questionable how accurately the surface exchanges can be simulated using LSMs, since terrestrial properties and processes have high variability and heterogeneity. Examinations with long-term and multi-site surface observations including both remotely sensed and ground observations are highly needed to make an objective evaluation on the effectiveness and uncertainty of LSMs at different circumstances. Among several atmospheric forcing required for the offline simulation of LSMs, incident surface solar radiation is one of the most significant components, since it plays a major role in total incoming energy into the land surface. The North American Land Data Assimilation System (NLDAS) and North American Regional Reanalysis (NARR) are two important data sources providing high-resolution surface solar radiation data for the use of research communities. In this study, these data are evaluated against field observations (AmeriFlux) to identify their advantages, deficiencies and sources of errors. The NLDAS incident solar radiation shows a pretty good agreement in monthly mean prior to the summer of 2001, while it overestimates after the summer of 2001 and its bias is pretty close to the EDAS. Two main error sources are identified: 1) GOES solar radiation was not used in the NLDAS for several months in 2001 and 2003, and 2) GOES incident solar radiation when available, was positively biased in year 2002. The known snow detection problem is sometimes identified in the NLDAS, since it is inherited from GOES incident solar radiation. The NARR consistently overestimates incident surface solar radiation, which might produce erroneous outputs if used in the LSMs. Further attention is given to the diurnal cycle of NLDAS. Because LSMs are designed to simulate radiation diurnal variation, they are always running at high temporal resolution (30-minutes to several hours). The NLDAS solar radiation data clearly show much smoothened diurnal cycles than observation in cloudy days, which is due to the lower spatial resolution of the NLDAS inherited from the GOES and the EDAS. Taking these problems discovered above into consideration, it is suggested that the NLDAS project work on reducing the systematic biases in the surface solar radiation estimates, so that the users could take full advantage from the data.
In-flight wind identification and soft landing control for autonomous unmanned powered parafoils
NASA Astrophysics Data System (ADS)
Luo, Shuzhen; Tan, Panlong; Sun, Qinglin; Wu, Wannan; Luo, Haowen; Chen, Zengqiang
2018-04-01
For autonomous unmanned powered parafoil, the ability to perform a final flare manoeuvre against the wind direction can allow a considerable reduction of horizontal and vertical velocities at impact, enabling a soft landing for a safe delivery of sensible loads; the lack of knowledge about the surface-layer winds will result in messing up terminal flare manoeuvre. Moreover, unknown or erroneous winds can also prevent the parafoil system from reaching the target area. To realize accurate trajectory tracking and terminal soft landing in the unknown wind environment, an efficient in-flight wind identification method merely using Global Positioning System (GPS) data and recursive least square method is proposed to online identify the variable wind information. Furthermore, a novel linear extended state observation filter is proposed to filter the groundspeed of the powered parafoil system calculated by the GPS information to provide a best estimation of the present wind during flight. Simulation experiments and real airdrop tests demonstrate the great ability of this method to in-flight identify the variable wind field, and it can benefit the powered parafoil system to fulfil accurate tracking control and a soft landing in the unknown wind field with high landing accuracy and strong wind-resistance ability.
Real-time Terrain Relative Navigation Test Results from a Relevant Environment for Mars Landing
NASA Technical Reports Server (NTRS)
Johnson, Andrew E.; Cheng, Yang; Montgomery, James; Trawny, Nikolas; Tweddle, Brent; Zheng, Jason
2015-01-01
Terrain Relative Navigation (TRN) is an on-board GN&C function that generates a position estimate of a spacecraft relative to a map of a planetary surface. When coupled with a divert, the position estimate enables access to more challenging landing sites through pin-point landing or large hazard avoidance. The Lander Vision System (LVS) is a smart sensor system that performs terrain relative navigation by matching descent camera imagery to a map of the landing site and then fusing this with inertial measurements to obtain high rate map relative position, velocity and attitude estimates. A prototype of the LVS was recently tested in a helicopter field test over Mars analog terrain at altitudes representative of Mars Entry Descent and Landing conditions. TRN ran in real-time on the LVS during the flights without human intervention or tuning. The system was able to compute estimates accurate to 40m (3 sigma) in 10 seconds on a flight like processing system. This paper describes the Mars operational test space definition, how the field test was designed to cover that operational envelope, the resulting TRN performance across the envelope and an assessment of test space coverage.
Effect of spatial organisation behaviour on upscaling the overland flow formation in an arable land
NASA Astrophysics Data System (ADS)
Silasari, Rasmiaditya; Blöschl, Günter
2014-05-01
Overland flow during rainfall events on arable land is important to investigate as it affects the land erosion process and water quality in the river. The formation of overland flow may happen through different ways (i.e. Hortonian overland flow, saturation excess overland flow) which is influenced by the surface and subsurface soil characteristics (i.e. land cover, soil infiltration rate). As the soil characteristics vary throughout the entire catchment, it will form distinct spatial patterns with organised or random behaviour. During the upscaling of hydrological processes from plot to catchment scale, this behaviour will become substantial since organised patterns will result in higher spatial connectivity and thus higher conductivity. However, very few of the existing studies explicitly address this effect of spatial organisations of the patterns in upscaling the hydrological processes to the catchment scale. This study will assess the upscaling of overland flow formation with concerns of spatial organisation behaviour of the patterns by application of direct field observations under natural conditions using video camera and soil moisture sensors and investigation of the underlying processes using a physical-based hydrology model. The study area is a Hydrological Open Air Laboratory (HOAL) located at Petzenkirchen, Lower Austria. It is a 64 ha catchment with land use consisting of arable land (87%), forest (6%), pasture (5%) and paved surfaces (2%). A video camera is installed 7m above the ground on a weather station mast in the middle of the arable land to monitor the overland flow patterns during rainfall events in a 2m x 6m plot scale. Soil moisture sensors with continuous measurement at different depth (5, 10, 20 and 50cm) are installed at points where the field is monitored by the camera. The patterns of overland flow formation and subsurface flow state at the plot scale will be generated using a coupled surface-subsurface flow physical-based hydrology model. The observation data will be assimilated into the model to verify the corresponding processes between surface and subsurface flow during the rainfall events. The patterns of conductivity then will be analyzed at catchment scale using the spatial stochastic analysis based on the classification of soil characteristics of the entire catchment. These patterns of conductivity then will be applied in the model at catchment scale to see how the organisational behaviour can affect the spatial connectivity of the hydrological processes and the results of the catchment response. A detailed modelling of the underlying processes in the physical-based model will allow us to see the direct effect of the spatial connectivity to the occurring surface and subsurface flow. This will improve the analysis of the effect of spatial organisations of the patterns in upscaling the hydrological processes from plot to catchment scale.
A Comparative Study of Simulated and Measured Main Landing Gear Noise for Large Civil Transports
NASA Technical Reports Server (NTRS)
Konig, Benedikt; Fares, Ehab; Ravetta, Patricio; Khorrami, Mehdi R.
2017-01-01
Computational results for the NASA 26%-scale model of a six-wheel main landing gear with and without a toboggan-shaped noise reduction fairing are presented. The model is a high-fidelity representation of a Boeing 777-200 aircraft main landing gear. A lattice Boltzmann method was used to simulate the unsteady flow around the model in isolation. The computations were conducted in free-air at a Mach number of 0.17, matching a recent acoustic test of the same gear model in the Virginia Tech Stability Wind Tunnel in its anechoic configuration. Results obtained on a set of grids with successively finer spatial resolution demonstrate the challenge in resolving/capturing the flow field for the smaller components of the gear and their associated interactions, and the resulting effects on the high-frequency segment of the farfield noise spectrum. Farfield noise spectra were computed based on an FWH integral approach, with simulated pressures on the model solid surfaces or flow-field data extracted on a set of permeable surfaces enclosing the model as input. Comparison of these spectra with microphone array measurements obtained in the tunnel indicated that, for the present complex gear model, the permeable surfaces provide a more accurate representation of farfield noise, suggesting that volumetric effects are not negligible. The present study also demonstrates that good agreement between simulated and measured farfield noise can be achieved if consistent post-processing is applied to both physical and synthetic pressure records at array microphone locations.
Generating a Long-Term Land Data Record from the AVHRR and MODIS Instruments
NASA Technical Reports Server (NTRS)
Pedelty, Jeffrey; Devadiga, Sadashiva; Masuoka, Edward; Brown, Molly; Pinzon, Jorge; Tucker, Compton; Vermote, Eric; Prince, Stephen; Nagol, Jyotheshwar; Justice, Christopher;
2007-01-01
The goal of NASA's Land Long Term Iiata Record (LTDR) project is to produce a consistent long term data set from the AVHRR and MODIS instruments for land climate studies. The project will create daily surface reflectance and normalized difference vegetation index (NDVI) products at a resolution of 0.05 deg., which is identical to the Climate Modeling Grid (CMG) used for MODIS products from EOS Terra and Aqua. Higher order products such as burned area, land surface temperature, albedo, bidirectional reflectance distribution function (BRDF) correction, leaf area index (LAI), and fraction of photosyntheticalIy active radiation absorbed by vegetation (fPAR), will be created. The LTDR project will reprocess Global Area Coverage (GAC) data from AVHRR sensors onboard NOAA satellites by applying the preprocessing improvements identified in the AVHRR Pathfinder Il project and atmospheric and BRDF corrections used in MODIS processing. The preprocessing improvements include radiometric in-flight vicarious calibration for the visible and near infrared channels and inverse navigation to relate an Earth location to each sensor instantaneous field of view (IFOV). Atmospheric corrections for Rayleigh scattering, ozone, and water vapor are undertaken, with aerosol correction being implemented. The LTDR also produces a surface reflectance product for channel 3 (3.75 micrometers). Quality assessment (QA) is an integral part of the LTDR production system, which is monitoring temporal trands in the AVHRR products using time-series approaches developed for MODIS land product quality assessment. The land surface reflectance products have been evaluated at AERONET sites. The AVHRR data record from LTDR is also being compared to products from the PAL (Pathfinder AVHRR Land) and GIMMS (Global Inventory Modeling and Mapping Studies) systems to assess the relative merits of this reprocessing vis-a-vis these existing data products. The LTDR products and associated information can be found at http://ltdr.nascom.nasa.gov/ltdr/ltdr.html.
Swimming in an Unsteady World.
Koehl, M A R; Cooper, T
2015-10-01
When animals swim in aquatic habitats, the water through which they move is usually flowing. Therefore, an important part of understanding the physics of how animals swim in nature is determining how they interact with the fluctuating turbulent water currents in their environment. We addressed this issue using microscopic larvae of invertebrates in "fouling communities" growing on docks and ships to ask how swimming affects the transport of larvae between moving water and surfaces from which they disperse and onto which they recruit. Field measurements of the motion of water over fouling communities were used to design realistic turbulent wavy flow in a laboratory wave-flume over early-stage fouling communities. Fine-scale measurements of rapidly-varying water-velocity fields were made using particle-image velocimetry, and of dye-concentration fields (analog for chemical cues from the substratum) were made using planar laser-induced fluorescence. We used individual-based models of larvae that were swimming, passively sinking, passively rising, or were passive and neutrally buoyant to determine how their trajectories were affected by their motion through the water, rotation by local shear, and transport by ambient flow. Swimmers moved up and down in the turbulent flow more than did neutrally buoyant larvae. Although more of the passive sinkers landed on substrata below them, and more passive risers on surfaces above, swimming was the best strategy for landing on surfaces if their location was not predictable (as is true for fouling communities). When larvae moved within 5 mm of surfaces below them, passive sinkers and neutrally-buoyant larvae landed on the substratum, whereas many of the swimmers were carried away, suggesting that settling larvae should stop swimming as they near a surface. Swimming and passively-rising larvae were best at escaping from a surface below them, as precompetent larvae must do to disperse away. Velocities, vorticities, and odor-concentrations encountered by larvae fluctuated rapidly, with peaks much higher than mean values. Encounters with concentrations of odor or with vorticities above threshold increased as larvae neared the substratum. Although microscopic organisms swim slowly, their locomotory behavior can affect where they are transported by the movement of ambient water as well as the signals they encounter when they move within a few centimeters of surfaces. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.
Li, Yi; Wu, Ji; Zheng, Chao; Huang, Rong Rong; Na, Yuhong; Yang, Fan; Wang, Zengshun; Wu, Di
2013-01-01
The objective of the study was to determine the effect of landing surface on plantar kinetics during a half-squat landing. Twenty male elite paratroopers with formal parachute landing training and over 2 years of parachute jumping experience were recruited. The subjects wore parachuting boots in which pressure sensing insoles were placed. Each subject was instructed to jump off a platform with a height of 60 cm, and land on either a hard or soft surface in a half-squat posture. Outcome measures were maximal plantar pressure, time to maximal plantar pressure (T-MPP), and pressure-time integral (PTI) upon landing on 10 plantar regions. Compared to a soft surface, hard surface produced higher maximal plantar pressure in the 1st to 4th metatarsal and mid-foot regions, but lower maximal plantar pressure in the 5th metatarsal region. Shorter T- MPP was found during hard surface landing in the 1st and 2nd metatarsal and medial rear foot. Landing on a hard surface landing resulted in a lower PTI than a soft surface in the 1stphalangeal region. For Chinese paratroopers, specific foot prosthesis should be designed to protect the1st to 4thmetatarsal region for hard surface landing, and the 1stphalangeal and 5thmetatarsal region for soft surface landing. Key Points Understanding plantar kinetics during the half-squat landing used by Chinese paratroopers can assist in the design of protective footwear. Compared to landing on a soft surface, a hard surface produced higher maximal plantar pressure in the 1st to 4th metatarsal and mid-foot regions, but lower maximal plantar pressure in the 5th metatarsal region. A shorter time to maximal plantar pressure was found during a hard surface landing in the 1st and 2nd metatarsals and medial rear foot. Landing on a hard surface resulted in a lower pressure-time integral than landing on a soft surface in the 1st phalangeal region. For Chinese paratroopers, specific foot prosthesis should be designed to protect the 1st to 4th metatarsal region for a hard surface landing, and the 1st phalangeal and 5th metatarsal region for a soft surface landing. PMID:24149145
NASA Astrophysics Data System (ADS)
Ning, Jicai; Gao, Zhiqiang; Meng, Ran; Xu, Fuxiang; Gao, Meng
2018-06-01
This study analyzed land use and land cover changes and their impact on land surface temperature using Landsat 5 Thematic Mapper and Landsat 8 Operational Land Imager and Thermal Infrared Sensor imagery of the Yellow River Delta. Six Landsat images comprising two time series were used to calculate the land surface temperature and correlated vegetation indices. The Yellow River Delta area has expanded substantially because of the deposited sediment carried from upstream reaches of the river. Between 1986 and 2015, approximately 35% of the land use area of the Yellow River Delta has been transformed into salterns and aquaculture ponds. Overall, land use conversion has occurred primarily from poorly utilized land into highly utilized land. To analyze the variation of land surface temperature, a mono-window algorithm was applied to retrieve the regional land surface temperature. The results showed bilinear correlation between land surface temperature and the vegetation indices (i.e., Normalized Difference Vegetation Index, Adjusted-Normalized Vegetation Index, Soil-Adjusted Vegetation Index, and Modified Soil-Adjusted Vegetation Index). Generally, values of the vegetation indices greater than the inflection point mean the land surface temperature and the vegetation indices are correlated negatively, and vice versa. Land surface temperature in coastal areas is affected considerably by local seawater temperature and weather conditions.
Precision Gas Sampling (PGS) Validation2011-2014 Final Campaign Report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tom, M. S.; Fischer, M. L.; Biraud, S. C.
In this field campaign, we used eddy covariance towers to quantify carbon, water, and energy fluxes from a pasture and a wheat field that were converted to switchgrass. The U.S. Department of Energy is investing in switchgrass as a cellulosic bioenergy crop, but there is little data available that could be used to develop or test land surface model representations of the crop. This campaign was a collaboration between Lawrence Berkeley National Laboratory and the U.S. Department of Agriculture Agricultural Research Service. Unfortunately, in 2011, Oklahoma had one of the most severe droughts on record, and the crop in onemore » of the switchgrass fields experienced almost complete die-off. The crop was replanted, but subsequent drought conditions prevented its establishment. Then, in April 2012, a large tornado demolished the instruments at our site in Woodward, Oklahoma. These two events meant that we have some interesting data on land response to extreme weather; however, we were not able to collect continuous data for annual sums as originally intended. We did observe that, because of the drought, the net ecosystem exchange of CO 2 was much lower in 2011 than in 2010. Concomitantly, sensible heat fluxes increased and latent heat fluxes decreased. These conditions would have large consequences for land surface forcing of convection. Data from all years were submitted to the Atmospheric Radiation Measurement Climate Research Facility Data Archive, and the sites were registered in AmeriFlux.« less
Relating GRACE terrestrial water storage variations to global fields of atmospheric forcing
NASA Astrophysics Data System (ADS)
Humphrey, Vincent; Gudmundsson, Lukas; Isabelle Seneviratne, Sonia
2015-04-01
Synoptic, seasonal and inter-annual fluctuations in atmospheric dynamics all influence terrestrial water storage, with impacts on ecosystems functions, human activities and land-climate interactions. Here we explore to which degree atmospheric variables can explain GRACE estimates of terrestrial water storage on different time scales. Since 2012, the most recent GRACE gravity field solutions (Release 05) can be used to monitor global changes in terrestrial water storage with an unprecedented level of accuracy over more than a decade. In addition, the release of associated gridded and post-processed products facilitates comparisons with other global datasets such as land surface model outputs or satellite observations. We investigate how decadal trends, inter-annual fluctuations as well as monthly anomalies of the seasonal cycle of terrestrial water storage can be related to fields of atmospheric forcing, including e.g. precipitation and temperature as estimated in global reanalysis products using statistical techniques. In the majority of the locations with high signal to noise ratio, both short and long-term fluctuations of total terrestrial water storage can be reconstructed to a large degree based on available atmospheric forcing. However, in some locations atmospheric forcing alone is not sufficient to explain the total change in water storage, suggesting strong influence of other processes. Within that framework, the question of an amplification or attenuation of atmospheric forcing through land-surface feedbacks and changes in long term water storage is discussed, also with respect to uncertainties and potential systematic biases in the results.
The atmospheric boundary layer in the CSIRO global climate model: simulations versus observations
NASA Astrophysics Data System (ADS)
Garratt, J. R.; Rotstayn, L. D.; Krummel, P. B.
2002-07-01
A 5-year simulation of the atmospheric boundary layer in the CSIRO global climate model (GCM) is compared with detailed boundary-layer observations at six locations, two over the ocean and four over land. Field observations, in the form of surface fluxes and vertical profiles of wind, temperature and humidity, are generally available for each hour over periods of one month or more in a single year. GCM simulations are for specific months corresponding to the field observations, for each of five years. At three of the four land sites (two in Australia, one in south-eastern France), modelled rainfall was close to the observed climatological values, but was significantly in deficit at the fourth (Kansas, USA). Observed rainfall during the field expeditions was close to climatology at all four sites. At the Kansas site, modelled screen temperatures (Tsc), diurnal temperature amplitude and sensible heat flux (H) were significantly higher than observed, with modelled evaporation (E) much lower. At the other three land sites, there is excellent correspondence between the diurnal amplitude and phase and absolute values of each variable (Tsc, H, E). Mean monthly vertical profiles for specific times of the day show strong similarities: over land and ocean in vertical shape and absolute values of variables, and in the mixed-layer and nocturnal-inversion depths (over land) and the height of the elevated inversion or height of the cloud layer (over the sea). Of special interest is the presence climatologically of early morning humidity inversions related to dewfall and of nocturnal low-level jets; such features are found in the GCM simulations. The observed day-to-day variability in vertical structure is captured well in the model for most sites, including, over a whole month, the temperature range at all levels in the boundary layer, and the mix of shallow and deep mixed layers. Weaknesses or unrealistic structure include the following, (a) unrealistic model mixed-layer temperature profiles over land in clear skies, related to use of a simple local first-order turbulence closure, (b) a tendency to overpredict cloud liquid water near the surface.
Relationships between aerodynamic roughness and land use and land cover in Baltimore, Maryland
Nicholas, F.W.; Lewis, J.E.
1980-01-01
Urbanization changes the radiative, thermal, hydrologic, and aerodynamic properties of the Earth's surface. Knowledge of these surface characteristics, therefore, is essential to urban climate analysis. Aerodynamic or surface roughness of urban areas is not well documented, however, because of practical constraints in measuring the wind profile in the presence of large buildings. Using an empirical method designed by Lettau, and an analysis of variance of surface roughness values calculated for 324 samples averaging 0.8 hectare (ha) of land use and land cover sample in Baltimore, Md., a strong statistical relation was found between aerodynamic roughness and urban land use and land cover types. Assessment of three land use and land cover systems indicates that some of these types have significantly different surface roughness characteristics. The tests further indicate that statistically significant differences exist in estimated surface roughness values when categories (classes) from different land use and land cover classification systems are used as surrogates. A Level III extension of the U.S. Geological Survey Level II land use and land cover classification system provided the most reliable results. An evaluation of the physical association between the aerodynamic properties of land use and land cover and the surface climate by numerical simulation of the surface energy balance indicates that changes in surface roughness within the range of values typical of the Level III categories induce important changes in the surface climate.
Building hydrologic information systems to promote climate resilience in the Blue Nile/Abay higlands
USDA-ARS?s Scientific Manuscript database
Climate adaptation requires information about climate and land-surface conditions – spatially distributed, and at scales of human influence (the field scale). This article describes a project aimed at combining meteorological data, satellite remote sensing, hydrologic modeling, and downscaled clima...
Xian, George
2008-01-01
By using both high-resolution orthoimagery and medium-resolution Landsat satellite imagery with other geospatial information, several land surface parameters including impervious surfaces and land surface temperatures for three geographically distinct urban areas in the United States – Seattle, Washington, Tampa Bay, Florida, and Las Vegas, Nevada, are obtained. Percent impervious surface is used to quantitatively define the spatial extent and development density of urban land use. Land surface temperatures were retrieved by using a single band algorithm that processes both thermal infrared satellite data and total atmospheric water vapor content. Land surface temperatures were analyzed for different land use and land cover categories in the three regions. The heterogeneity of urban land surface and associated spatial extents were shown to influence surface thermal conditions because of the removal of vegetative cover, the introduction of non-transpiring surfaces, and the reduction in evaporation over urban impervious surfaces. Fifty years of in situ climate data were integrated to assess regional climatic conditions. The spatial structure of surface heating influenced by landscape characteristics has a profound influence on regional climate conditions, especially through urban heat island effects.
A comparison of all-weather land surface temperature products
NASA Astrophysics Data System (ADS)
Martins, Joao; Trigo, Isabel F.; Ghilain, Nicolas; Goettche, Frank-M.; Ermida, Sofia; Olesen, Folke-S.; Gellens-Meulenberghs, Françoise; Arboleda, Alirio
2017-04-01
The Satellite Application Facility on Land Surface Analysis (LSA-SAF, http://landsaf.ipma.pt) has been providing land surface temperature (LST) estimates using SEVIRI/MSG on an operational basis since 2006. The LSA-SAF service has since been extended to provide a wide range of satellite-based quantities over land surfaces, such as emissivity, albedo, radiative fluxes, vegetation state, evapotranspiration, and fire-related variables. Being based on infra-red measurements, the SEVIRI/MSG LST product is limited to clear-sky pixels only. Several all-weather LST products have been proposed by the scientific community either based on microwave observations or using Soil-Vegetation-Atmosphere Transfer models to fill the gaps caused by clouds. The goal of this work is to provide a nearly gap-free operational all-weather LST product and compare these approaches. In order to estimate evapotranspiration and turbulent energy fluxes, the LSA-SAF solves the surface energy budget for each SEVIRI pixel, taking into account the physical and physiological processes occurring in vegetation canopies. This task is accomplished with an adapted SVAT model, which adopts some formulations and parameters of the Tiled ECMWF Scheme for Surface Exchanges over Land (TESSEL) model operated at the European Center for Medium-range Weather Forecasts (ECMWF), and using: 1) radiative inputs also derived by LSA-SAF, which includes surface albedo, down-welling fluxes and fire radiative power; 2) a land-surface characterization obtained by combining the ECOCLIMAP database with both LSA-SAF vegetation products and the H(ydrology)-SAF snow mask; 3) meteorological fields from ECMWF forecasts interpolated to SEVIRI pixels, and 4) soil moisture derived by the H-SAF and LST from LSA-SAF. A byproduct of the SVAT model is surface skin temperature, which is needed to close the surface energy balance. The model skin temperature corresponds to the radiative temperature of the interface between soil and atmosphere, which is assumed to have no heat storage. The modelled skin temperatures are in fair agreement with LST directly estimated from SEVIRI observations. However, in contrast to LST retrievals from SEVIRI/MSG (or other infrared sensors) the SVAT model solves the energy budget equation under all-sky conditions. The SVAT surface skin temperature is then used to fill gaps in LST fields caused by clouds. Since under cloudy conditions the direct incoming solar radiation is greatly reduced, thermal balance at the surface is more easily achieved and directional effects are also less important. Therefore, a better performance of the model skin temperature may be expected. In contrast, under clear skies the satellite LST showed to be more reliable, since the SVAT model shows biases in the daily amplitude of the skin temperature. In the context of the GlobTemperature project (http://www.globtemperature.info/), all-weather LST datasets using AMSR-E microwave radiances were produced, which are compared here to the SVAT-based LST. Both products were validated against in situ data - particularly from Gobabeb & Farm Heimat (Namibia), and Évora (Portugal) - to show that under cloudy conditions the agreement between in-situ LST and modelled skin temperature is acceptable. Compared to the SVAT-based LST, AMSR-E LST is closer to satellite observations (level 2 product); the complementarity of the two approaches is assessed.
Magnetism and the interior of the moon
NASA Technical Reports Server (NTRS)
Dyal, P.; Parkin, C. W.; Daily, W. D.
1974-01-01
During the time period 1961-1972, 11 magnetometers were sent to the moon. The primary purpose of this paper is to review the results of lunar magnetometer data analysis, with emphasis on the lunar interior. Magnetic fields have been measured on the lunar surface at the Apollo 12, 14, 15, and 16 landing sites. The remanent field values at these sites are 38, 103 (maximum), 3, and 327 gammas (maximum), respectively. Simultaneous magnetic field and solar plasma pressure measurements show that the Apollo 12 and 16 remanent fields are compressed during times of high plasma dynamic pressure. Apollo 15 and 16 subsatellite magnetometers have mapped in detail the field above portions of the lunar surface and have placed an upper limit on the global permanent dipole moment. Satellite and surface measurements show strong evidence that the lunar crust is magnetized over much of the lunar globe. Magnetic fields are stronger in highland regions than in mare regions and stronger on the lunar far side than on the near side. The largest magnetic anomaly measured to date is between the craters Van de Graaff and Aitken on the lunar far side.
NASA Astrophysics Data System (ADS)
Telesca, V.; Copertino, V. A.; Scavone, G.; Pastore, V.; Dal Sasso, S.
2009-04-01
Most of the hydrological models are by now founded on field and satellite data integration. In fact, the use of remote sensing techniques supplies the frequent lack of field-measured variables and parameters required to apply evaluation models of the hydrological cycle components at a regional scale. These components are very sensitive to the climatic and surface features and conditions. Remote sensing represent a complementary contribution to in situ investigation methodologies, furnishing repeated and real time observations. Naturally, the interest of these techniques is tied up to the existence of a solid correlation among the greatness to evaluate and the remote sensing information obtainable from the images. In this context, satellite remote sensing has become a basic tool since it allows the regular monitoring of extensive areas. Different surface variables and parameters can be extracted from the combination of the multi-spectral information contained in a satellite image. Land Surface Temperature (LST) is a fundamental parameter to estimate most of the components of the hydrological cycle and the soil-atmosphere energy balance, such as the net radiation, the sensible heat flux and the actual evapotranspiration. Besides, LST maps can be used in models for the fire monitoring and prevention. The aim of this work is to realize, exploiting the contribution of the remote sensing, some Land Surface Temperature maps, applying different "Split Windows" algorithms and to compare them with the "Day/Night" LST/MODIS, to select the best algorithm to apply in a Two-Source Energy Balance model (STSEB). Integrated into a rainfall/runoff model, it can contribute to cope with problems of land management for the protection from natural hazards. In particular, the energy balance procedure will be included into a model for the ‘in continuous' simulation and the forecast of floods. Another important application of our model is tied up to the forecast of scenarios connected to drought problems. In this context, they can contribute to the planning and the realization of mitigation interventions for the desertification risk.
NASA Astrophysics Data System (ADS)
Unnikrishnan, C. K.; Rajeevan, M.; Rao, S. Vijaya Bhaskara
2016-06-01
The direct impact of high resolution land surface initialization on the forecast bias in a regional climate model in recent years over Indian summer monsoon region is investigated. Two sets of regional climate model simulations are performed, one with a coarse resolution land surface initial conditions and second one used a high resolution land surface data for initial condition. The results show that all monsoon years respond differently to the high resolution land surface initialization. The drought monsoon year 2009 and extended break periods were more sensitive to the high resolution land surface initialization. These results suggest that the drought monsoon year predictions can be improved with high resolution land surface initialization. Result also shows that there are differences in the response to the land surface initialization within the monsoon season. Case studies of heat wave and a monsoon depression simulation show that, the model biases were also improved with high resolution land surface initialization. These results show the need for a better land surface initialization strategy in high resolution regional models for monsoon forecasting.
Quantifying surface albedo and other direct biogeophysical climate forcings of forestry activities.
Bright, Ryan M; Zhao, Kaiguang; Jackson, Robert B; Cherubini, Francesco
2015-09-01
By altering fluxes of heat, momentum, and moisture exchanges between the land surface and atmosphere, forestry and other land-use activities affect climate. Although long recognized scientifically as being important, these so-called biogeophysical forcings are rarely included in climate policies for forestry and other land management projects due to the many challenges associated with their quantification. Here, we review the scientific literature in the fields of atmospheric science and terrestrial ecology in light of three main objectives: (i) to elucidate the challenges associated with quantifying biogeophysical climate forcings connected to land use and land management, with a focus on the forestry sector; (ii) to identify and describe scientific approaches and/or metrics facilitating the quantification and interpretation of direct biogeophysical climate forcings; and (iii) to identify and recommend research priorities that can help overcome the challenges of their attribution to specific land-use activities, bridging the knowledge gap between the climate modeling, forest ecology, and resource management communities. We find that ignoring surface biogeophysics may mislead climate mitigation policies, yet existing metrics are unlikely to be sufficient. Successful metrics ought to (i) include both radiative and nonradiative climate forcings; (ii) reconcile disparities between biogeophysical and biogeochemical forcings, and (iii) acknowledge trade-offs between global and local climate benefits. We call for more coordinated research among terrestrial ecologists, resource managers, and coupled climate modelers to harmonize datasets, refine analytical techniques, and corroborate and validate metrics that are more amenable to analyses at the scale of an individual site or region. © 2015 John Wiley & Sons Ltd.
Near-surface turbulence as a missing link in modeling evapotranspiration-soil moisture relationships
NASA Astrophysics Data System (ADS)
Haghighi, Erfan; Kirchner, James W.
2017-07-01
Despite many efforts to develop evapotranspiration (ET) models with improved parametrizations of resistance terms for water vapor transfer into the atmosphere, estimates of ET and its partitioning remain prone to bias. Much of this bias could arise from inadequate representations of physical interactions near nonuniform surfaces from which localized heat and water vapor fluxes emanate. This study aims to provide a mechanistic bridge from land-surface characteristics to vertical transport predictions, and proposes a new physically based ET model that builds on a recently developed bluff-rough bare soil evaporation model incorporating coupled soil moisture-atmospheric controls. The newly developed ET model explicitly accounts for (1) near-surface turbulent interactions affecting soil drying and (2) soil-moisture-dependent stomatal responses to atmospheric evaporative demand that influence leaf (and canopy) transpiration. Model estimates of ET and its partitioning were in good agreement with available field-scale data, and highlight hidden processes not accounted for by commonly used ET schemes. One such process, nonlinear vegetation-induced turbulence (as a function of vegetation stature and cover fraction) significantly influences ET-soil moisture relationships. Our results are particularly important for water resources and land use planning of semiarid sparsely vegetated ecosystems where soil surface interactions are known to play a critical role in land-climate interactions. This study potentially facilitates a mathematically tractable description of the strength (i.e., the slope) of the ET-soil moisture relationship, which is a core component of models that seek to predict land-atmosphere coupling and its feedback to the climate system in a changing climate.
NASA Technical Reports Server (NTRS)
Shen, Suhung; Leptoukh, Gregory G.; Gerasimov, Irina
2010-01-01
Surface air temperature is a critical variable to describe the energy and water cycle of the Earth-atmosphere system and is a key input element for hydrology and land surface models. It is a very important variable in agricultural applications and climate change studies. This is a preliminary study to examine statistical relationships between ground meteorological station measured surface daily maximum/minimum air temperature and satellite remotely sensed land surface temperature from MODIS over the dry and semiarid regions of northern China. Studies were conducted for both MODIS-Terra and MODIS-Aqua by using year 2009 data. Results indicate that the relationships between surface air temperature and remotely sensed land surface temperature are statistically significant. The relationships between the maximum air temperature and daytime land surface temperature depends significantly on land surface types and vegetation index, but the minimum air temperature and nighttime land surface temperature has little dependence on the surface conditions. Based on linear regression relationship between surface air temperature and MODIS land surface temperature, surface maximum and minimum air temperatures are estimated from 1km MODIS land surface temperature under clear sky conditions. The statistical errors (sigma) of the estimated daily maximum (minimum) air temperature is about 3.8 C(3.7 C).
NASA Astrophysics Data System (ADS)
Hodges, A. T.; Bolles, K.; Forman, S. L.
2017-12-01
The drought that struck the U.S. Great Plains during the 1930s was one of the most intensedroughts in the region in the last millennium, spurring a major environmental and public healthcrisis. A prominent explanation for the cause of the "dust bowl" centers on the expansion ofagriculture and poor land management practices leading to widespread soil erosion. Thisprevalent hypothesis largely excludes the impacts of naturally occurring land surface processesthat contribute to eolian erosion and dust emissivity, particularly during periods of drought. Priorwork generally focuses on economic and sociological factors in agricultural decision-making forindividual fields or farms.This study utilizes early aerial photography collected by the Soil Conservation Service in 1936 ofBaca County, Colorado, to identify and quantify spatial relationships between geomorphicprocesses and anthropogenic activities impacting dust emission. From the holdings at theNational Archives, 25 photos covering 125 km2 scanned at 1200dpi are combined into acontinuous mosaic, and geo-referenced at RMSE 78.6 m2 . Detailed land cover analyses areundertaken in ArcGIS to classify uncultivated and cultivated surfaces; cultivated surfaces arefurther divided by surface agricultural operations in relation to erosion and dust emission (e.g.listing, contour furrows, terraces, circuitous plowing, listing, eolian transport, and fallow fieldswith and without vegetation). The classified surface is overlaid with National ResourceConservation Service surveys and Soil Conservation Service reconnaissance surveys of land useand erosion carried out in 1936 to infer to potential emissivity of a given cultivated surface. Inthis way, it becomes possible to evaluate human influence on dust emission in one of theworst-struck counties of the Dust Bowl and potentially identify other causative factors to thissignificant period in American history.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhu, Chunmei; Leung, Lai R.; Gochis, David
2009-11-29
The influence of antecedent soil moisture on North American monsoon system (NAMS) precipitation variability was explored using the MM5 mesoscale model coupled with the Variable Infiltration Capacity (VIC) land surface model. Sensitivity experiments were performed with extreme wet and dry initial soil moisture conditions for both the 1984 wet monsoon year and the 1989 dry year. The MM5-VIC model reproduced the key features of NAMS in 1984 and 1989 especially over northwestern Mexico. Our modeling results indicate that the land surface has memory of the initial soil wetness prescribed at the onset of the monsoon that persists over most ofmore » the region well into the monsoon season (e.g. until August). However, in contrast to the classical thermal contrast concept, where wetter soils lead to cooler surface temperatures, less land-sea thermal contrast, weaker monsoon circulations and less precipitation, the coupled model consistently demonstrated a positive soil moisture – precipitation feedback. Specifically, anomalously wet premonsoon soil moisture always lead to enhanced monsoon precipitation, and the reverse was also true. The surface temperature changes induced by differences in surface energy flux partitioning associated with pre-monsoon soil moisture anomalies changed the surface pressure and consequently the flow field in the coupled model, which in turn changed moisture convergence and, accordingly, precipitation patterns. Both the largescale circulation change and local land-atmospheric interactions in response to premonsoon soil moisture anomalies play important roles in the coupled model’s positive soil moisture monsoon precipitation feedback. However, the former may be sensitive to the strength and location of the thermal anomalies, thus leaving open the possibility of both positive and negative soil moisture precipitation feedbacks.« less
2014-04-30
CAPE CANAVERAL, Fla. – A technician vents off the gas from the propellant lines of NASA's Project Morpheus prototype lander after it landed from a free-flight test at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The 98-second test began at 1:57 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending more than 800 feet at a peak speed of 36 mph. The vehicle, with its recently installed autonomous landing and hazard avoidance technology, or ALHAT, sensors surveyed the hazard field to determine safe landing sites. Morpheus then flew forward and downward covering approximately 1300 feet while performing a 78-foot divert to simulate a hazard avoidance maneuver. The lander descended and landed on a dedicated pad inside the ALHAT hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, which are green propellants. These new capabilities could be used in future efforts to deliver cargo to planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
Morpheus 1C preps & post launch activities
2014-03-11
CAPE CANAVERAL, Fla. - The Project Morpheus prototype lander lifts off in the automated landing and hazard avoidance technology, or ALHAT, hazard field for its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
Lunar portable magnetometer experiment
NASA Technical Reports Server (NTRS)
Dyal, P.; Parkin, C. W.; Sonett, C. P.; Dubois, R. L.; Simmons, G.
1972-01-01
The purpose of the Apollo 16 lunar portable magnetometer (LPM) experiment is to measure the permanent magnetic field at different geological sites on the lunar surface. The LPM field measurements are a vector sum of the steady remanent field from the lunar crust and of the time-varying ambient fields. The remanent magnetic fields measured in the Descartes region are the largest extraterrestrial fields yet measured in situ. These measurements show for the first time that the Descartes highlands have a stronger remanent magnetization than do the mare regions of the previous Apollo landing sites. The experimental technique used in the LPM experiment is described and the preliminary results obtained are discussed.
Estimation of Key Parameters of the Coupled Energy and Water Model by Assimilating Land Surface Data
NASA Astrophysics Data System (ADS)
Abdolghafoorian, A.; Farhadi, L.
2017-12-01
Accurate estimation of land surface heat and moisture fluxes, as well as root zone soil moisture, is crucial in various hydrological, meteorological, and agricultural applications. Field measurements of these fluxes are costly and cannot be readily scaled to large areas relevant to weather and climate studies. Therefore, there is a need for techniques to make quantitative estimates of heat and moisture fluxes using land surface state observations that are widely available from remote sensing across a range of scale. In this work, we applies the variational data assimilation approach to estimate land surface fluxes and soil moisture profile from the implicit information contained Land Surface Temperature (LST) and Soil Moisture (SM) (hereafter the VDA model). The VDA model is focused on the estimation of three key parameters: 1- neutral bulk heat transfer coefficient (CHN), 2- evaporative fraction from soil and canopy (EF), and 3- saturated hydraulic conductivity (Ksat). CHN and EF regulate the partitioning of available energy between sensible and latent heat fluxes. Ksat is one of the main parameters used in determining infiltration, runoff, groundwater recharge, and in simulating hydrological processes. In this study, a system of coupled parsimonious energy and water model will constrain the estimation of three unknown parameters in the VDA model. The profile of SM (LST) at multiple depths is estimated using moisture diffusion (heat diffusion) equation. In this study, the uncertainties of retrieved unknown parameters and fluxes are estimated from the inverse of Hesian matrix of cost function which is computed using the Lagrangian methodology. Analysis of uncertainty provides valuable information about the accuracy of estimated parameters and their correlation and guide the formulation of a well-posed estimation problem. The results of proposed algorithm are validated with a series of experiments using a synthetic data set generated by the simultaneous heat and water (SHAW) model. In addition, the feasibility of extending this algorithm to use remote sensing observations that have low temporal resolution is examined by assimilating the limited number of land surface moisture and temperature observations.
NASA Technical Reports Server (NTRS)
Matolak, D. W.; Apaza, Rafael; Foore, Lawrence R.
2006-01-01
We describe a recently completed wideband wireless channel characterization project for the 5 GHz Microwave Landing System (MLS) extension band, for airport surface areas. This work included mobile measurements at large and small airports, and fixed point-to-point measurements. Mobile measurements were made via transmission from the air traffic control tower (ATCT), or from an airport field site (AFS), to a receiving ground vehicle on the airport surface. The point-to-point measurements were between ATCT and AFSs. Detailed statistical channel models were developed from all these measurements. Measured quantities include propagation path loss and power delay profiles, from which we obtain delay spreads, frequency domain correlation (coherence bandwidths), fading amplitude statistics, and channel parameter correlations. In this paper we review the project motivation, measurement coordination, and illustrate measurement results. Example channel modeling results for several propagation conditions are also provided, highlighting new findings.
Urqueta, Harry; Jódar, Jorge; Herrera, Christian; Wilke, Hans-G; Medina, Agustín; Urrutia, Javier; Custodio, Emilio; Rodríguez, Jazna
2018-01-15
Land surface temperature (LST) seems to be related to the temperature of shallow aquifers and the unsaturated zone thickness (∆Z uz ). That relationship is valid when the study area fulfils certain characteristics: a) there should be no downward moisture fluxes in an unsaturated zone, b) the soil composition in terms of both, the different horizon materials and their corresponding thermal and hydraulic properties, must be as homogeneous and isotropic as possible, c) flat and regular topography, and d) steady state groundwater temperature with a spatially homogeneous temperature distribution. A night time Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image and temperature field measurements are used to test the validity of the relationship between LST and ∆Z uz at the Pampa del Tamarugal, which is located in the Atacama Desert (Chile) and meets the above required conditions. The results indicate that there is a relation between the land surface temperature and the unsaturated zone thickness in the study area. Moreover, the field measurements of soil temperature indicate that shallow aquifers dampen both the daily and the seasonal amplitude of the temperature oscillation generated by the local climate conditions. Despite empirically observing the relationship between the LST and ∆Z uz in the study zone, such a relationship cannot be applied to directly estimate ∆Z uz using temperatures from nighttime thermal satellite images. To this end, it is necessary to consider the soil thermal properties, the soil surface roughness and the unseen water and moisture fluxes (e.g., capillarity and evaporation) that typically occur in the subsurface. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Technical Reports Server (NTRS)
Peters-Lidard, Christa D.; Kumar, Sujay V.; Santanello, Joseph A., Jr.; Reichle, Rolf H.
2009-01-01
The Land Information System (LIS; http://lis.gsfc.nasa.gov; Kumar et al., 2006; Peters- Lidard et al.,2007) is a flexible land surface modeling framework that has been developed with the goal of integrating satellite- and ground-based observational data products and advanced land surface modeling techniques to produce optimal fields of land surface states and fluxes. As such, LIS represents a step towards the next generation land component of an integrated Earth system model. In recognition of LIS object-oriented software design, use and impact in the land surface and hydrometeorological modeling community, the LIS software was selected ase co-winner of NASA's 2005 Software of the Year award. LIS facilitates the integration of observations from Earth-observing systems and predictions and forecasts from Earth System and Earth science models into the decision-making processes of partnering agency and national organizations. Due to its flexible software design, LIS can serve both as a Problem Solving Environment (PSE) for hydrologic research to enable accurate global water and energy cycle predictions, and as a Decision Support System (DSS) to generate useful information for application areas including disaster management, water resources management, agricultural management, numerical weather prediction, air quality and military mobility assessment. LIS has evolved from two earlier efforts North American Land Data Assimilation System (NLDAS; Mitchell et al. 2004) and Global Land Data Assimilation System (GLDAS; Rodell al. 2004) that focused primarily on improving numerical weather prediction skills by improving the characterization of the land surface conditions. Both of GLDAS and NLDAS now use specific configurations of the LIS software in their current implementations. In addition, LIS was recently transitioned into operations at the US Air Force Weather Agency (AFWA) to ultimately replace their Agricultural Meteorology (AGRMET) system, and is also used routinely by NOAA's National Centers for Environmental Prediction (NCEP)/Environmental Modeling Center (EMC) for their land data assimilation systems to support weather and climate modeling. LIS not only consolidates the capabilities of these two systems, but also enables a much larger variety of configurations with respect to horizontal spatial resolution, input datasets and choice of land surface model through "plugins,". As described in Kumar et al., 2007, and demonstrated in Case et al., 2008, and Santanello et al., 2009, LIS has been coupled to the Weather Research and Forecasting (WRF) model to support studies of land-atmosphere coupling the enabling ensembles of land surface states to be tested against multiple representations of the atmospheric boundary layer. LIS has also been demonstrated for parameter estimation as described in Peters-Lidard et al. (2008) and Santanello et al. (2007), who showed that the use of sequential remotely sensed soil moisture products can be used to derive soil hydraulic and texture properties given a sufficient dynamic range in the soil moisture retrievals and accurate precipitation inputs. LIS has also recently been demonstrated for multi-model data assimilation (Kumar et al., 2008) using an Ensemble Kalman Filter for sequential assimilation of soil moisture, snow, and temperature. Ongoing work has demonstrated the value of bias correction as part of the filter, and also that of joint calibration and assimilation. Examples and case studies demonstrating the capabilities and impacts of LIS for hydrometeoroogical modeling, assimilation and parameter estimation will be presented as advancements towards the next generation of integrated observation and modeling systems.
Land Surface Microwave Emissivity Dynamics: Observations, Analysis and Modeling
NASA Technical Reports Server (NTRS)
Tian, Yudong; Peters-Lidard, Christa D.; Harrison, Kenneth W.; Kumar, Sujay; Ringerud, Sarah
2014-01-01
Land surface microwave emissivity affects remote sensing of both the atmosphere and the land surface. The dynamical behavior of microwave emissivity over a very diverse sample of land surface types is studied. With seven years of satellite measurements from AMSR-E, we identified various dynamical regimes of the land surface emission. In addition, we used two radiative transfer models (RTMs), the Community Radiative Transfer Model (CRTM) and the Community Microwave Emission Modeling Platform (CMEM), to simulate land surface emissivity dynamics. With both CRTM and CMEM coupled to NASA's Land Information System, global-scale land surface microwave emissivities were simulated for five years, and evaluated against AMSR-E observations. It is found that both models have successes and failures over various types of land surfaces. Among them, the desert shows the most consistent underestimates (by approx. 70-80%), due to limitations of the physical models used, and requires a revision in both systems. Other snow-free surface types exhibit various degrees of success and it is expected that parameter tuning can improve their performances.
Mapping 2000 2010 Impervious Surface Change in India Using Global Land Survey Landsat Data
NASA Technical Reports Server (NTRS)
Wang, Panshi; Huang, Chengquan; Brown De Colstoun, Eric C.
2017-01-01
Understanding and monitoring the environmental impacts of global urbanization requires better urban datasets. Continuous field impervious surface change (ISC) mapping using Landsat data is an effective way to quantify spatiotemporal dynamics of urbanization. It is well acknowledged that Landsat-based estimation of impervious surface is subject to seasonal and phenological variations. The overall goal of this paper is to map 200-02010 ISC for India using Global Land Survey datasets and training data only available for 2010. To this end, a method was developed that could transfer the regression tree model developed for mapping 2010 impervious surface to 2000 using an iterative training and prediction (ITP) approach An independent validation dataset was also developed using Google Earth imagery. Based on the reference ISC from the validation dataset, the RMSE of predicted ISC was estimated to be 18.4%. At 95% confidence, the total estimated ISC for India between 2000 and 2010 is 2274.62 +/- 7.84 sq km.
NASA Technical Reports Server (NTRS)
deGoncalves, Luis Gustavo G.; Shuttleworth, William J.; Vila, Daniel; Larroza, Elaine; Bottino, Marcus J.; Herdies, Dirceu L.; Aravequia, Jose A.; De Mattos, Joao G. Z.; Toll, David L.; Rodell, Matthew;
2008-01-01
The definition and derivation of a 5-year, 0.125deg, 3-hourly atmospheric forcing dataset for the South America continent is described which is appropriate for use in a Land Data Assimilation System and which, because of the limited surface observational networks available in this region, uses remotely sensed data merged with surface observations as the basis for the precipitation and downward shortwave radiation fields. The quality of this data set is evaluated against available surface observations. There are regional difference in the biases for all variables in the dataset, with biases in precipitation of the order 0-1 mm/day and RMSE of 5-15 mm/day, biases in surface solar radiation of the order 10 W/sq m and RMSE of 20 W/sq m, positive biases in temperature typically between 0 and 4 K, depending on region, and positive biases in specific humidity around 2-3 g/Kg in tropical regions and negative biases around 1-2 g/Kg further south.
Investigation of land-use spectral signatures. Ph.D. Thesis. Final Report
NASA Technical Reports Server (NTRS)
Hagewood, J. F.
1975-01-01
A technique was developed to obtain bidirectional reflectance data from natural surfaces by using a folding mirror to transfer the reflected energy from the test surface to a spectroradiometer. The folding mirror was a first surface reflector made by stretching Mylar vacuum coated with aluminum over a light weight frame. The optically folding mirror was positioned over the test surfaces with a moveable platform for both laboratory and field tests. Field tests were conducted using a tethered balloon system to position the folding mirror. A spectroradiometer was designed and built specifically for this investigation. The spectroradiometer had an angular field of view of twenty-four minutes in one axis and ten minutes in the other axis. The radiometer was capable of detecting energies in small bandwidths throughout the electromagnetic spectrum from 0.3 microns to 3.0 microns. Bidirectional reflectance data and variations in the data with source angles were obtained for Saint Augustine grass, Bermuda grass, and a black alluvium soil from the Mississippi River delta.
Alterations to groundwater recharge due to anthropogenic landscape change
NASA Astrophysics Data System (ADS)
Han, Dongmei; Currell, Matthew J.; Cao, Guoliang; Hall, Benjamin
2017-11-01
The impacts of anthropogenic modifications to the landscape on groundwater recharge rates, locations, and mechanisms are reviewed. The two major categories of change examined are conversion of land for agriculture and urbanization, both of which have significant effects on groundwater recharge. Techniques for identifying and quantifying the changes in recharge due to these impacts are discussed. Land-clearing for agriculture and surface water transfer for irrigation have resulted in order of magnitude increases in recharge rates in many semi-arid regions worldwide, causing ongoing land and water salinization and water-logging problems. While increased recharge by irrigation return flow may alleviate shallow groundwater depletion in some settings, this is complicated by the effect of unsaturated zone thickening, which reduces the fraction of potential recharge becoming actual recharge, and may result in new water quality risks such as nitrate contamination. Expansion of urban and peri-urban land and their associated surface and sub-surface infrastructure results in complex water balance changes that re-distribute groundwater recharge locations, modify recharge mechanism(s) and result in variable impacts on recharge rates (e.g., overall net decrease, increase or minimal change) and quality. While changes to groundwater recharge resulting from conversion of land for agriculture are relatively well understood, less is documented about the changes resulting from urbanization, due to a paucity of data from field-based studies. Two case studies from Beijing, China and Melbourne Australia are examined, which highlight these impacts and demonstrate some potential methodological techniques for this topic.
Comparison of global cloud liquid water path derived from microwave measurements with CERES-MODIS
NASA Astrophysics Data System (ADS)
Yi, Y.; Minnis, P.; Huang, J.; Lin, B.; Ayers, K.; Sun-Mack, S.; Fan, A.
Cloud liquid water path LWP is a crucial parameter for climate studies due to the link that it provides between the atmospheric hydrological and radiative budgets Satellite-based visible infrared techniques such as the Visible Infrared Solar Split-Window Technique VISST can retrieve LWP for water clouds assumes single-layer over a variety of surfaces If the water clouds are overlapped by ice clouds the LWP of the underlying clouds can not be retrieved by such techniques However microwave techniques may be used to retrieve the LWP underneath ice clouds due to the microwave s insensitivity to cloud ice particles LWP is typically retrieved from satellite-observed microwave radiances only over ocean due to variations of land surface temperature and emissivity Recently Deeter and Vivekanandan 2006 developed a new technique for retrieving LWP over land In order to overcome the sensitivity to land surface temperature and emissivity their technique is based on a parameterization of microwave polarization-difference signals In this study a similar regression-based technique for retrieving LWP over land and ocean using Advanced Microwave Scanning Radiometer - EOS AMSR-E measurements is developed Furthermore the microwave surface emissivities are also derived using clear-sky fields of view based on the Clouds and Earth s Radiant Energy System Moderate-resolution Imaging Spectroradiometer CERES-MODIS cloud mask These emissivities are used in an alternate form of the technique The results are evaluated using independent measurements such
Using NASA Techniques to Atmospherically Correct AWiFS Data for Carbon Sequestration Studies
NASA Technical Reports Server (NTRS)
Holekamp, Kara L.
2007-01-01
Carbon dioxide is a greenhouse gas emitted in a number of ways, including the burning of fossil fuels and the conversion of forest to agriculture. Research has begun to quantify the ability of vegetative land cover and oceans to absorb and store carbon dioxide. The USDA (U.S. Department of Agriculture) Forest Service is currently evaluating a DSS (decision support system) developed by researchers at the NASA Ames Research Center called CASA-CQUEST (Carnegie-Ames-Stanford Approach-Carbon Query and Evaluation Support Tools). CASA-CQUEST is capable of estimating levels of carbon sequestration based on different land cover types and of predicting the effects of land use change on atmospheric carbon amounts to assist land use management decisions. The CASA-CQUEST DSS currently uses land cover data acquired from MODIS (the Moderate Resolution Imaging Spectroradiometer), and the CASA-CQUEST project team is involved in several projects that use moderate-resolution land cover data derived from Landsat surface reflectance. Landsat offers higher spatial resolution than MODIS, allowing for increased ability to detect land use changes and forest disturbance. However, because of the rate at which changes occur and the fact that disturbances can be hidden by regrowth, updated land cover classifications may be required before the launch of the Landsat Data Continuity Mission, and consistent classifications will be needed after that time. This candidate solution investigates the potential of using NASA atmospheric correction techniques to produce science-quality surface reflectance data from the Indian Remote Sensing Advanced Wide-Field Sensor on the RESOURCESAT-1 mission to produce land cover classification maps for the CASA-CQUEST DSS.
Fine dust emissions in sandy and silty agricultural soils
USDA-ARS?s Scientific Manuscript database
Dust emissions from strong winds are common in arid and semi-arid regions and occur under both natural and managed land systems. A portable field wind tunnel has been developed to allow measurements of dust emissions from soil surfaces to test the premise that dust concentrations are highly correlat...
Land application of spent gypsum from ditch filters: phosphorus source or sink?
USDA-ARS?s Scientific Manuscript database
Agricultural drainage ditches can provide a direct connection between fields and surface waters, and some have been shown to deliver high loads of phosphorus (P) to sensitive water bodies. A potential way to reduce nutrient loads in drainage ditches is to install filter structures containing P sorbi...
USDA-ARS?s Scientific Manuscript database
Thermal-infrared remote sensing of land surface temperature provides valuable information for quantifying root-zone water availability, evapotranspiration (ET) and crop condition. This paper describes a robust but relatively simple thermal-based energy balance model that parameterizes the key soil/s...
Corn yield and nutrient uptake response to subsurface-lateral bands application of poultry litter
USDA-ARS?s Scientific Manuscript database
Poultry litter is nutrient rich and traditionally land-applied by broadcast on the soil surface which can lead to potential environmental hazards. This application method leaves PL vulnerable to transport from the field to nearby water bodies and contributes significant amounts of greenhouse gases (...
30 CFR 1206.101 - What definitions apply to this subpart?
Code of Federal Regulations, 2011 CFR
2011-07-01
... region situated over one or more subsurface oil and gas reservoirs and encompassing at least the outermost boundaries of all oil and gas accumulations known within those reservoirs, vertically projected to the land surface. State oil and gas regulatory agencies usually name onshore fields and designate...
NASA Astrophysics Data System (ADS)
Comyn-Platt, Edward; Clark, Douglas; Blyth, Eleanor
2016-04-01
The UK is required to provide accurate estimates of the UK greenhouse gas (GHG; CO2, CH4 and N2O) emissions for the UNFCCC (United Nations Framework Convention on Climate Change). Process based land surface models (LSMs), such as the Joint UK Land Environment Simulator (JULES), attempt to provide such estimates based on environmental (e.g. land use and soil type) and meteorological conditions. The standard release of JULES focusses on the water and carbon cycles, however, it has long been suggested that a coupled carbon-nitrogen scheme could enhance simulations. This is of particular importance when estimating agricultural emission inventories where the carbon cycle is effectively managed via the human application of nitrogen based fertilizers. JULES-ECOSSE-FUN (JEF) links JULES with the Estimation of Carbon in Organic Soils - Sequestration and Emission (ECOSSE) model and the Fixation and Uptake of Nitrogen (FUN) model as a means of simulating C:N coupling. This work presents simulations from the standard release of JULES and the most recent incarnation of the JEF coupled system at the point and field scale. Various configurations of JULES and JEF were calibrated and fine-tuned based on comparisons with observations from three UK field campaigns (Crichton, Harwood Forest and Brattleby) specifically chosen to represent the managed vegetation types that cover the UK. The campaigns included flux tower and chamber measurements of CO2, CH4 and N2O amongst other meteorological parameters and records of land management such as application of fertilizer and harvest date at the agricultural sites. Based on the results of these comparisons, JULES and/or JEF will be used to provide simulations on the regional and national scales in order to provide improved estimates of the total UK emission inventory.
NASA Astrophysics Data System (ADS)
Joseph, E.; Nalli, N. R.; Oyola, M. I.; Morris, V. R.; Sakai, R.
2014-12-01
An overview is given of research to validate or improve the retrieval of environmental data records (EDRs) from recently deployed hyperspectral IR satellite sensors such as Suomi NPP Cross-track Infrared Microwave Sounder Suite (CrIMSS). The effort centers around several surface field intensive campaigns that are designed or leveraged for EDR validation. These data include ship-based observations of upper air ozone, pressure, temperature and relative humidity soundings; aerosol and cloud properties; and sea surface temperature. Similar intensive data from two land-based sites are also utilized as well. One site, the Howard University Beltsville site, is at a single point location but has a comprehensive array of observations for an extended period of time. The other land site, presently being deployed by the University at Albany, is under development with limited upper air soundings but will have regionally distributed surface based microwave profiling of temperature and relative humidity on the scale of 10 - 50 km and other standard meteorological observations. Combined these observations provide data that are unique in their wide range including, a variety of meteorological conditions and atmospheric compositions over the ocean and urban-suburban environments. With the distributed surface sites the variability of atmospheric conditions are captured concurrently across a regional spatial scale. Some specific examples are given of comparisons of moisture and temperature correlative EDRs from the satellite sensors and surface based observations. An additional example is given of the use of this data to correct sea surface temperature (SST) retrieval biases from the hyperspectral IR satellite observations due to aerosol contamination.
Seasonal canopy reflectance patterns of wheat, sorghum, and soybean
NASA Technical Reports Server (NTRS)
Kanemasu, E. T.
1974-01-01
An investigation was conducted of canopy-reflectance patterns as a basis for the determination of surface conditions. Two fields each of wheat, sorghum, and soybeans were selected in a bottom land area. One field contained a dark-colored, silty clay loam and the other a light-colored, silt loam. The study suggests that the reflectance ratio of the 545- to 655-nm-wavelengths may be used as an indicator of crop growth.
NASA Technical Reports Server (NTRS)
Blankenship, Clay; Case, Jonathan L.; Zavodsky, Bradley
2015-01-01
Land surface models are important components of numerical weather prediction (NWP) models, partitioning incoming energy into latent and sensitive heat fluxes that affect boundary layer growth and destabilization. During warm-season months, diurnal heating and convective initiation depend strongly on evapotranspiration and available boundary layer moisture, which are substantially affected by soil moisture content. Therefore, to properly simulate warm-season processes in NWP models, an accurate initialization of the land surface state is important for accurately depicting the exchange of heat and moisture between the surface and boundary layer. In this study, soil moisture retrievals from the Soil Moisture and Ocean Salinity (SMOS) satellite radiometer are assimilated into the Noah Land Surface Model via an Ensemble Kalman Filter embedded within the NASA Land Information System (LIS) software framework. The output from LIS-Noah is subsequently used to initialize runs of the Weather Research and Forecasting (WRF) NWP model. The impact of assimilating SMOS retrievals is assessed by initializing the WRF model with LIS-Noah output obtained with and without SMOS data assimilation. The southeastern United States is used as the domain for a preliminary case study. During the summer months, there is extensive irrigation in the lower Mississippi Valley for rice and other crops. The irrigation is not represented in the meteorological forcing used to drive the LIS-Noah integration, but the irrigated areas show up clearly in the SMOS soil moisture retrievals, resulting in a case with a large difference in initial soil moisture conditions. The impact of SMOS data assimilation on both Noah soil moisture fields and on short-term (0-48 hour) WRF weather forecasts will be presented.
Land surface temperature measurements from EOS MODIS data
NASA Technical Reports Server (NTRS)
Wan, Zhengming
1995-01-01
A significant progress has been made in TIR instrumentation which is required to establish the spectral BRDF/emissivity knowledge base of land-surface materials and to validate the land-surface temperature (LST) algorithms. The SIBRE (spectral Infrared Bidirectional Reflectance and Emissivity) system and a TIR system for measuring spectral directional-hemispherical emissivity have been completed and tested successfully. Optical properties and performance features of key components (including spectrometer, and TIR source) of these systems have been characterized by integrated use of local standards (blackbody and reference plates). The stabilization of the spectrometer performance was improved by a custom designed and built liquid cooling system. Methods and procedures for measuring spectral TIR BRDF and directional-hemispheric emissivity with these two systems have been verified in sample measurements. These TIR instruments have been used in the laboratory and the field, giving very promising results. The measured spectral emissivities of water surface are very close to the calculated values based on well established water refractive index values in published papers. Preliminary results show that the TIR instruments can be used for validation of the MODIS LST algorithm in homogeneous test sites. The beta-3 version of the MODIS LST software is being prepared for its delivery scheduled in the early second half of this year.
Land Surface Modeling and Data Assimilation to Support Physical Precipitation Retrievals for GPM
NASA Technical Reports Server (NTRS)
Peters-Lidard, Christa D.; Tian. Yudong; Kumar, Sujay; Geiger, James; Choudhury, Bhaskar
2010-01-01
Objective: The objective of this proposal is to provide a routine land surface modeling and data assimilation capability for GPM in order to provide global land surface states that are necessary to support physical precipitation retrieval algorithms over land. It is well-known that surface emission, particularly over the range of frequencies to be included in GPM, is sensitive to land surface states, including soil properties, vegetation type and greenness, soil moisture, surface temperature, and snow cover, density, and grain size. Therefore, providing a robust capability to routinely provide these critical land states is essential to support GPM-era physical retrieval algorithms over land.
2014-01-21
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander touches down in the autonomous landing and hazard avoidance technology, or ALHAT, hazard field after launching on its fourth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 64-second test began at 1:15 p.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending about 305 feet, significantly increasing the ascent velocity from the last test. The lander flew forward, covering about 358 feet in 25 seconds before descending and landing within 15 inches of its target on a dedicated pad inside the ALHAT hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://www.nasa.gov/centers/johnson/exploration/morpheus. Photo credit: NASA/Kim Shiflett
2014-01-21
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander touched down in the autonomous landing and hazard avoidance technology, or ALHAT, hazard field after launching on its fourth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 64-second test began at 1:15 p.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending about 305 feet, significantly increasing the ascent velocity from the last test. The lander flew forward, covering about 358 feet in 25 seconds before descending and landing within 15 inches of its target on a dedicated pad inside the ALHAT hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://www.nasa.gov/centers/johnson/exploration/morpheus. Photo credit: NASA/Kim Shiflett
NASA Astrophysics Data System (ADS)
Lubis, M. Z.; Taki, H. M.; Anurogo, W.; Pamungkas, D. S.; Wicaksono, P.; Aprilliyanti, T.
2017-12-01
Potential land drought mapping on Batam is needed to determine the distribution of areas that are very potential to the physical drought of the land. It is because the drought is always threatening on the long dry season. This research integrates remote sensing science with Geographic Information System (GIS). This research aims to map the distribution of land drought potential in Batam Island. The parameters used in this research are land use, Land Surface Temperature (LST), Potential dryness of land on the Batam island. The resulting map indicates the existence of five potential drought classes on the island of Batam. The area of very low drought potential is 2629.45 ha, mostly located in the Sungai Beduk sub-district. High drought potential with an area of 7081.39 ha is located in Sekupang sub-district. The distribution of very high land drought potential is in Batam city and Nongsa sub-district with area of 15600.12 ha. The coefficient of determination (R 2) is 0.6279. This indicates a strong positive relationship between field LST and modelled LST.
NASA Astrophysics Data System (ADS)
Thomsen, L. M.; Baartman, J. E. M.; Barneveld, R. J.; Starkloff, T.; Stolte, J.
2015-04-01
Quantification of soil roughness, i.e. the irregularities of the soil surface due to soil texture, aggregates, rock fragments and land management, is important as it affects surface storage, infiltration, overland flow, and ultimately sediment detachment and erosion. Roughness has been measured in the field using both contact methods (such as roller chain and pinboard) and sensor methods (such as stereophotogrammetry and terrestrial laser scanning (TLS)). A novel depth-sensing technique, originating in the gaming industry, has recently become available for earth sciences: the Xtion Pro method. Roughness data obtained using various methods are assumed to be similar; this assumption is tested in this study by comparing five different methods to measure roughness in the field on 1 m2 agricultural plots with different management (ploughing, harrowing, forest and direct seeding on stubble) in southern Norway. Subsequently, the values were used as input for the LISEM soil erosion model to test their effect on the simulated hydrograph at catchment scale. Results show that statistically significant differences between the methods were obtained only for the fields with direct seeding on stubble; for the other land management types the methods were in agreement. The spatial resolution of the contact methods was much lower than for the sensor methods (10 000 versus at least 57 000 points per square metre). In terms of costs and ease of use in the field, the Xtion Pro method is promising. Results from the LISEM model indicate that especially the roller chain overestimated the random roughness (RR) values and the model subsequently calculated less surface runoff than measured. In conclusion, the choice of measurement method for roughness data matters and depends on the required accuracy, resolution, mobility in the field and available budget. It is recommended to use only one method within one study.
NASA Astrophysics Data System (ADS)
Thomsen, L. M.; Baartman, J. E. M.; Barneveld, R. J.; Starkloff, T.; Stolte, J.
2014-11-01
Quantification of soil roughness, i.e. the irregularities of the soil surface due to soil texture, aggregates, rock fragments and land management, is important as it affects surface storage, infiltration, overland flow and ultimately sediment detachment and erosion. Roughness has been measured in the field using both contact methods, such as roller chain and pinboard, and sensor methods, such as stereophotogrammetry and terrestrial laser scanning (TLS). A novel depth sensing technique, originating in the gaming industry, has recently become available for earth sciences; the Xtion Pro method. Roughness data obtained using various methods are assumed to be similar; this assumption is tested in this study by comparing five different methods to measure roughness in the field on 1 m2 agricultural plots with different management (ploughing, harrowing, forest and direct seeding on stubble) in southern Norway. Subsequently, the values were used as input for the LISEM soil erosion model to test their effect on the simulated hydrograph on catchment scale. Results show that statistically significant differences between the methods were obtained only for the fields with direct drilling on stubble; for the other land management types the methods were in agreement. The spatial resolution of the contact methods was much lower than for the sensor methods (10 000 versus at least 57 000 points per m2 respectively). In terms of costs and ease of handling in the field, the Xtion Pro method is promising. Results from the LISEM model indicate that especially the roller chain underestimated the RR values and the model thereby calculated less surface runoff than measured. In conclusion: the choice of measurement method for roughness data matters and depends on the required accuracy, resolution, mobility in the field and available budget. It is recommended to use only one method within one study.
Analysis of passive microwave signatures over snow-covered mountainous area
NASA Astrophysics Data System (ADS)
Kim, R. S.; Durand, M. T.
2015-12-01
Accurate knowledge of snow distribution over mountainous area is critical for climate studies and the passive microwave(PM) measurements have been widely used and invested in order to obtain information about snowpack properties. Understanding and analyzing the signatures for the explicit inversion of the remote sensing data from land surfaces is required for successful using of passive microwave sensors but this task is often ambiguous due to the large variability of physical conditions and object types. In this paper, we discuss the pattern of measured brightness temperatures and emissivities at vertical and horizontal polarization over the frequency range of 10.7 to 89 GHz of land surfaces under various snow and vegetation conditions. The Multiband polarimetric Scanning Radiometer(PSR) imagery is used over NASA Cold Land Processes Field Experiment(CLPX) study area with ground-based measurements of snow depth and snow properties. Classification of snow under various conditions in mountainous area is implemented based on different patterns of microwave signatures.
High Resolution Land Surface Modeling with the next generation Land Data Assimilation Systems
NASA Astrophysics Data System (ADS)
Kumar, S. V.; Eylander, J.; Peters-Lidard, C.
2005-12-01
Knowledge of land surface processes is important to many real-world applications such as agricultural production, water resources management, and flood predication. The Air Force Weather Agency (AFWA) has provided the USDA and other customers global soil moisture and temperature data for the past 30 years using the agrometeorological data assimilation model (now called AGRMET), merging atmospheric data. Further, accurate initialization of land surface conditions has been shown to greatly influence and improve weather forecast model and seasonal-to-interannual climate predictions. The AFWA AGRMET model exploits real time precipitation observations and analyses, global forecast model and satellite data to generate global estimates of soil moisture, soil temperature and other land surface states at 48km spatial resolution. However, to truly address the land surface initialization and climate prediction problem, and to mitigate the errors introduced by the differences in spatial scales of models, representations of land surface conditions need to be developed at the same fine scales such as that of cloud resolving models. NASA's Goddard Space Flight Center has developed an offline land data assimilation system known as the Land Information System (LIS) capable of modeling land atmosphere interactions at spatial resolutions as fine as 1km. LIS provides a software architecture that integrates the use of the state of the art land surface models, data assimilation techniques, and high performance computing and data management tools. LIS also employs many high resolution surface parameters such as the NASA Earth Observing System (EOS)-era products. In this study we describe the development of a next generation high resolution land surface modeling and data assimilation system, combining the capabilities of LIS and AGRMET. We investigate the influence of high resolution land surface data and observations on the land surface conditions by comparing with the operational AGRMET outputs.
NASA Astrophysics Data System (ADS)
Chen, Xuelong; Su, Bob
2017-04-01
Remote sensing has provided us an opportunity to observe Earth land surface with a much higher resolution than any of GCM simulation. Due to scarcity of information for land surface physical parameters, up-to-date GCMs still have large uncertainties in the coupled land surface process modeling. One critical issue is a large amount of parameters used in their land surface models. Thus remote sensing of land surface spectral information can be used to provide information on these parameters or assimilated to decrease the model uncertainties. Satellite imager could observe the Earth land surface with optical, thermal and microwave bands. Some basic Earth land surface status (land surface temperature, canopy height, canopy leaf area index, soil moisture etc.) has been produced with remote sensing technique, which already help scientists understanding Earth land and atmosphere interaction more precisely. However, there are some challenges when applying remote sensing variables to calculate global land-air heat and water exchange fluxes. Firstly, a global turbulent exchange parameterization scheme needs to be developed and verified, especially for global momentum and heat roughness length calculation with remote sensing information. Secondly, a compromise needs to be innovated to overcome the spatial-temporal gaps in remote sensing variables to make the remote sensing based land surface fluxes applicable for GCM model verification or comparison. A flux network data library (more 200 flux towers) was collected to verify the designed method. Important progress in remote sensing of global land flux and evaporation will be presented and its benefits for GCM models will also be discussed. Some in-situ studies on the Tibetan Plateau and problems of land surface process simulation will also be discussed.
NASA Technical Reports Server (NTRS)
Trail, M.; Tsimpidi, A. P.; Liu, P.; Tsigaridis, Konstantinos; Hu, Y.; Nenes, A.; Stone, B.; Russell, A. G.
2013-01-01
The impact of future land use and land cover changes (LULCC) on regional and global climate is one of the most challenging aspects of understanding anthropogenic climate change. We study the impacts of LULCC on regional climate in the southeastern U.S. by downscaling the NASA Goddard Institute for Space Studies global climate model E to the regional scale using a spectral nudging technique with the Weather Research and Forecasting Model. Climate-relevant meteorological fields are compared for two southeastern U.S. LULCC scenarios to the current land use/cover for four seasons of the year 2050. In this work it is shown that reforestation of cropland in the southeastern U.S. tends to warm surface air by up to 0.5 K, while replacing forested land with cropland tends to cool the surface air by 0.5 K. Processes leading to this response are investigated and sensitivity analyses conducted. The sensitivity analysis shows that results are most sensitive to changes in albedo and the stomatal resistance. Evaporative cooling of croplands also plays an important role in regional climate. Implications of LULCC on air quality are discussed. Summertime warming associated with reforestation of croplands could increase the production of some secondary pollutants, while a higher boundary layer will decrease pollutant concentrations; wintertime warming may decrease emissions from biomass burning from wood stoves
NASA Technical Reports Server (NTRS)
Case, Johnathan L.; Mungai, John; Sakwa, Vincent; Kabuchanga, Eric; Zavodsky, Bradley T.; Limaye, Ashutosh S.
2014-01-01
Flooding and drought are two key forecasting challenges for the Kenya Meteorological Service (KMS). Atmospheric processes leading to excessive precipitation and/or prolonged drought can be quite sensitive to the state of the land surface, which interacts with the planetary boundary layer (PBL) of the atmosphere providing a source of heat and moisture. The development and evolution of precipitation systems are affected by heat and moisture fluxes from the land surface, particularly within weakly-sheared environments such as in the tropics and sub-tropics. These heat and moisture fluxes during the day can be strongly influenced by land cover, vegetation, and soil moisture content. Therefore, it is important to represent the land surface state as accurately as possible in land surface and numerical weather prediction (NWP) models. Enhanced regional modeling capabilities have the potential to improve forecast guidance in support of daily operations and high-impact weather over eastern Africa. KMS currently runs a configuration of the Weather Research and Forecasting (WRF) NWP model in real time to support its daily forecasting operations, making use of the NOAA/National Weather Service (NWS) Science and Training Resource Center's Environmental Modeling System (EMS) to manage and produce the KMS-WRF runs on a regional grid over eastern Africa. Two organizations at the NASA Marshall Space Flight Center in Huntsville, AL, SERVIR and the Shortterm Prediction Research and Transition (SPoRT) Center, have established a working partnership with KMS for enhancing its regional modeling capabilities through new datasets and tools. To accomplish this goal, SPoRT and SERVIR is providing enhanced, experimental land surface initialization datasets and model verification capabilities to KMS as part of this collaboration. To produce a land-surface initialization more consistent with the resolution of the KMS-WRF runs, the NASA Land Information System (LIS) is run at a comparable resolution to provide real-time, daily soil initialization data in place of data interpolated from the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) model soil moisture and temperature fields. Additionally, realtime green vegetation fraction (GVF) data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership (Suomi- NPP) satellite will be incorporated into the KMS-WRF runs, once it becomes publicly available from the National Environmental Satellite Data and Information Service (NESDIS). Finally, model verification capabilities will be transitioned to KMS using the Model Evaluation Tools (MET; Brown et al. 2009) package in conjunction with a dynamic scripting package developed by SPoRT (Zavodsky et al. 2014), to help quantify possible improvements in simulated temperature, moisture and precipitation resulting from the experimental land surface initialization. Furthermore, the transition of these MET tools will enable KMS to monitor model forecast accuracy in near real time. This paper presents preliminary efforts to improve land surface model initialization over eastern Africa in support of operations at KMS. The remainder of this extended abstract is organized as follows: The collaborating organizations involved in the project are described in Section 2; background information on LIS and the configuration for eastern Africa is presented in Section 3; the WRF configuration used in this modeling experiment is described in Section 4; sample experimental WRF output with and without LIS initialization data are given in Section 5; a summary is given in Section 6 followed by acknowledgements and references.
Assessment of MERRA-2 Land Surface Energy Flux Estimates
NASA Technical Reports Server (NTRS)
Draper, Clara; Reichle, Rolf; Koster, Randal
2017-01-01
In MERRA-2, observed precipitation is inserted in place of model-generated precipitation at the land surface. The use of observed precipitation was originally developed for MERRA-Land(a land-only replay of MERRA with model-generated precipitation replaced with observations).Previously shown that the land hydrology in MERRA-2 and MERRA-Land is better than MERRA. We test whether the improved land surface hydrology in MERRA-2 leads to the expected improvements in the land surface energy fluxes and 2 m air temperatures (T2m).
[Influence of different types of surface on the diversity of soil fauna in Beijing Olympic Park].
Song, Ying-shi; Li, Xiao-wen; Li, Feng; Li, Hai-mei
2015-04-01
Soil fauna are impacted by urbanization. In order to explore the stress of different surface covers on diversity and community structure of soil fauna, we conducted this experiment in Beijing Olympic Park. In autumn of 2013, we used Baermann and Tullgren methods to study the diversity of soil fauna in the depth of 0-5 cm, 5-10 cm, 10-15 cm under four different land covers i.e. bared field (BF), totally impervious surface (TIS), partly impervious surface (PIS) and grassland (GL). The results showed that the total number of soil fauna in 100 cm3 was in order of GL (210) > PIS (193) > TIS (183) > BF (90), and the number of nematodes accounted for 72.0%-92.8% of the total number. On the vertical level, except for the TIS, the other three types of surface soil fauna had the surface gathered phenomenon. The Shannon diversity index and the Pielou evenness index of BF were lower, but the Simpson dominance index was higher than in the other land covers. The Shannon index and Margalef richness indes of GL were higher than those of the other land covers. The Shannon indexes of TIS and PIS were between the BF and GL. Except for the TIS and GL, the similarity indexes were between 0.4-0.5, indicating moderate non-similar characteristics. The diversity of soil fauna was significantly correlated with temperature, pH and available potassium.
NASA Astrophysics Data System (ADS)
Rivalland, Vincent; Gascoin, Simon; Etchanchu, Jordi; Coustau, Mathieu; Cros, Jérôme; Tallec, Tiphaine
2016-04-01
The Sentinel-2 mission will enable to monitor the land cover and the vegetation phenology at high-resolution (HR) every 5 days. However, current Land Surface Models (LSM) typically use land cover and vegetation parameters derived from previous low to mid resolution satellite missions. Here we studied the effect of introducing Sentinel-2-like data in the simulation of the land surface energy and water fluxes in a region dominated by cropland. Simulations were performed with the ISBA-SURFEX LSM, which is used in the operational hydrometeorological chain of Meteo-France for hydrological forecasts and drought monitoring. By default, SURFEX vegetation land surface parameters and temporal evolution are from the ECOCLIMAP II European database mostly derived from MODIS products at 1 km resolution. The model was applied to an experimental area of 30 km by 30 km in south west France. In this area the resolution of ECOCLIMAP is coarser than the typical size of a crop field. This means that several crop types can be mixed in a pixel. In addition ECOCLIMAP provides a climatology of the vegetation phenology and thus does not account for the interannual effects of the climate and land management on the crop growth. In this work, we used a series of 26 Formosat-2 images at 8-m resolution acquired in 2006. From this dataset, we derived a land cover map and a leaf area index map (LAI) at each date, which were substituted to the ECOCLIMAP land cover map and the LAI maps. The model output water and energy fluxes were compared to a standard simulation using ECOCLIMAP only and to in situ measurements of soil moisture, latent and sensible heat fluxes. The results show that the introduction of the HR products improved the timing of the evapotranspiration. The impact was the most visible on the crops having a growing season in summer (maize, sunflower), because the growth period is more sensitive to the climate.
A Thermal Imaging Instrument with Uncooled Detectors
NASA Astrophysics Data System (ADS)
Joseph, A. T.; Barrentine, E. M.; Brown, A. D.
2017-12-01
In this work, we perform an instrument concept study for sustainable thermal imaging over land with uncooled detectors. The National Research Council's Committee on Implementation of a Sustained Land Imaging Program has identified the inclusion of a thermal imager as critical for both current and future land imaging missions. Such an imaging instrument operating in two bands located at approximately 11 and 12 microns (for example, in Landsat 8, and also Landsat 9 when launched) will provide essential information for furthering our hydrologic understanding at scales of human influence, and produce field-scale moisture information through accurate retrievals of evapotranspiration (ET). Landsat 9 is slated to recycle the TIRS-2 instrument launched with Landsat 8 that uses cooled quantum well infrared photodetectors (QWIPs), hence requiring expensive and massive cryocooler technology to achieve its required spectral and spatial accuracies. Our goal is to conceptualize and develop a thermal imaging instrument which leverages recent and imminent technology advances in uncooled detectors. Such detector technology will offer the benefit of greatly reduced instrument cost, mass, and power at the expense of some acceptable loss in detector sensitivity. It would also allow a thermal imaging instrument to be fielded on board a low-cost platform, e.g., a CubeSat. Sustained and enhanced land imaging is crucial for providing high-quality science data on change in land use, forest health, crop status, environment, and climate. Accurate satellite mapping of ET at the agricultural field scale (the finest spatial scale of the environmental processes of interest) requires high-quality thermal data to produce the corresponding accurate land surface temperature (LST) retrievals used to drive an ET model. Such an imaging instrument would provide important information on the following: 1) the relationship between land-use and land/water management practices and water use dynamics; 2) the interconnections between anthropogenic water management and changes in hydrologic budget at scales of human influence; and 3) complimentary field-scale moisture values for interpreting coarser resolution datasets. There is a clear need for continuing innovation in thermal remote sensing detector technology.
Modelling study of sea breezes in a complex coastal environment
NASA Astrophysics Data System (ADS)
Cai, X.-M.; Steyn, D. G.
This study investigates a mesoscale modelling of sea breezes blowing from a narrow strait into the lower Fraser valley (LFV), British Columbia, Canada, during the period of 17-20 July, 1985. Without a nudging scheme in the inner grid, the CSU-RAMS model produces satisfactory wind and temperature fields during the daytime. In comparison with observation, the agreement indices for surface wind and temperature during daytime reach about 0.6 and 0.95, respectively, while the agreement indices drop to 0.4 at night. In the vertical, profiles of modelled wind and temperature generally agree with tethersonde data collected on 17 and 19 July. The study demonstrates that in late afternoon, the model does not capture the advection of an elevated warm layer which originated from land surfaces outside of the inner grid. Mixed layer depth (MLD) is calculated from model output of turbulent kinetic energy field. Comparison of MLD results with observation shows that the method generates a reliable MLD during the daytime, and that accurate estimates of MLD near the coast require the correct simulation of wind conditions over the sea. The study has shown that for a complex coast environment like the LFV, a reliable modelling study depends not only on local surface fluxes but also on elevated layers transported from remote land surfaces. This dependence is especially important when local forcings are weak, for example, during late afternoon and at night.
NASA Astrophysics Data System (ADS)
Fu, Xiao Lei; Jin, Bao Ming; Jiang, Xiao Lei; Chen, Cheng
2018-06-01
Data assimilation is an efficient way to improve the simulation/prediction accuracy in many fields of geosciences especially in meteorological and hydrological applications. This study takes unscented particle filter (UPF) as an example to test its performance at different two probability distribution, Gaussian and Uniform distributions with two different assimilation frequencies experiments (1) assimilating hourly in situ soil surface temperature, (2) assimilating the original Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) once per day. The numerical experiment results show that the filter performs better when increasing the assimilation frequency. In addition, UPF is efficient for improving the soil variables (e.g., soil temperature) simulation/prediction accuracy, though it is not sensitive to the probability distribution for observation error in soil temperature assimilation.
Weather Research and Forecasting Model Wind Sensitivity Study at Edwards Air Force Base, CA
NASA Technical Reports Server (NTRS)
Watson, Leela R.; Bauman, William H., III
2008-01-01
NASA prefers to land the space shuttle at Kennedy Space Center (KSC). When weather conditions violate Flight Rules at KSC, NASA will usually divert the shuttle landing to Edwards Air Force Base (EAFB) in Southern California. But forecasting surface winds at EAFB is a challenge for the Spaceflight Meteorology Group (SMG) forecasters due to the complex terrain that surrounds EAFB, One particular phenomena identified by SMG is that makes it difficult to forecast the EAFB surface winds is called "wind cycling". This occurs when wind speeds and directions oscillate among towers near the EAFB runway leading to a challenging deorbit bum forecast for shuttle landings. The large-scale numerical weather prediction models cannot properly resolve the wind field due to their coarse horizontal resolutions, so a properly tuned high-resolution mesoscale model is needed. The Weather Research and Forecasting (WRF) model meets this requirement. The AMU assessed the different WRF model options to determine which configuration best predicted surface wind speed and direction at EAFB, To do so, the AMU compared the WRF model performance using two hot start initializations with the Advanced Research WRF and Non-hydrostatic Mesoscale Model dynamical cores and compared model performance while varying the physics options.
1969-11-23
Sitting on the lunar surface, this magnetometer provided new data on the Moon’s magnetic field. This was one of the instruments used during the Apollo 12 mission. The second manned lunar landing mission, Apollo 12 launched from launch pad 39-A at Kennedy Space Center in Florida on November 14, 1969 via a Saturn V launch vehicle. The Saturn V vehicle was developed by the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun. Aboard Apollo 12 was a crew of three astronauts: Alan L. Bean, pilot of the Lunar Module (LM), Intrepid; Richard Gordon, pilot of the Command Module (CM), Yankee Clipper; and Spacecraft Commander Charles Conrad. The LM, Intrepid, landed astronauts Conrad and Bean on the lunar surface in what’s known as the Ocean of Storms while astronaut Richard Gordon piloted the CM, Yankee Clipper, in a parking orbit around the Moon. Lunar soil activities included the deployment of the Apollo Lunar Surface Experiments Package (ALSEP), finding the unmanned Surveyor 3 that landed on the Moon on April 19, 1967, and collecting 75 pounds (34 kilograms) of rock samples. Apollo 12 safely returned to Earth on November 24, 1969.
NASA Technical Reports Server (NTRS)
Mascaro, Giuseppe; Vivoni, Enrique R.; Deidda, Roberto
2010-01-01
Accounting for small-scale spatial heterogeneity of soil moisture (theta) is required to enhance the predictive skill of land surface models. In this paper, we present the results of the development, calibration, and performance evaluation of a downscaling model based on multifractal theory using aircraft!based (800 m) theta estimates collected during the southern Great Plains experiment in 1997 (SGP97).We first demonstrate the presence of scale invariance and multifractality in theta fields of nine square domains of size 25.6 x 25.6 sq km, approximately a satellite footprint. Then, we estimate the downscaling model parameters and evaluate the model performance using a set of different calibration approaches. Results reveal that small-scale theta distributions are adequately reproduced across the entire region when coarse predictors include a dynamic component (i.e., the spatial mean soil moisture
2014-01-21
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander is transported to a launch pad at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The prototype lander is being prepared for its fourth free flight test at Kennedy. Morpheus will launch from the ground over a flame trench and then descend and land on a dedicated pad inside the autonomous landing and hazard avoidance technology, or ALHAT, hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://www.nasa.gov/centers/johnson/exploration/morpheus. Photo credit: NASA/Cory Huston
Morpheus Alhat Tether Test Preparations
2014-03-27
CAPE CANAVERAL, Fla. – NASA's Project Morpheus prototype lander is positioned near a new launch site at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida for a tether test. The launch pad was moved to a different location at the landing facility to support the next phase of flight testing. Project Morpheus tests NASA’s automated landing and hazard avoidance technology, or ALHAT, and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. In the foreground of the photo is the ALHAT field. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Ben Smegelsky
2014-01-21
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander is being lifted by crane for positioning on a launch pad at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The prototype lander is being prepared for its fourth free flight test at Kennedy. Morpheus will launch from the ground over a flame trench and then descend and land on a dedicated pad inside the autonomous landing and hazard avoidance technology, or ALHAT, hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://www.nasa.gov/centers/johnson/exploration/morpheus. Photo credit: NASA/Cory Huston
Buto, Susan G.; Gold, Brittany L.; Jones, Kimberly A.
2014-01-01
Irrigation in arid environments can alter the natural rate at which salts are dissolved and transported to streams. Irrigated agricultural lands are the major anthropogenic source of dissolved solids in the Upper Colorado River Basin (UCRB). Understanding the location, spatial distribution, and irrigation status of agricultural lands and the method used to deliver water to agricultural lands are important to help improve the understanding of agriculturally derived dissolved-solids loading to surface water in the UCRB. Irrigation status is the presence or absence of irrigation on an agricultural field during the selected growing season or seasons. Irrigation method is the system used to irrigate a field. Irrigation method can broadly be grouped into sprinkler or flood methods, although other techniques such as drip irrigation are used in the UCRB. Flood irrigation generally causes greater dissolved-solids loading to streams than sprinkler irrigation. Agricultural lands in the UCRB mapped by state agencies at varying spatial and temporal resolutions were assembled and edited to represent conditions in the UCRB between 2007 and 2010. Edits were based on examination of 1-meter resolution aerial imagery collected between 2009 and 2011. Remote sensing classification techniques were used to classify irrigation status for the June to September growing seasons between 2007 and 2010. The final dataset contains polygons representing approximately 1,759,900 acres of agricultural lands in the UCRB. Approximately 66 percent of the mapped agricultural lands were likely irrigated during the study period.
Land Use and Environmental Variability Impacts on the Phenology of Arid Agro-Ecosystems.
Romo-Leon, Jose Raul; van Leeuwen, Willem J D; Castellanos-Villegas, Alejandro
2016-02-01
The overexploitation of water resources in arid environments often results in abandonment of large extensions of agricultural lands, which may (1) modify phenological trends, and (2) alter the sensitivity of specific phenophases to environmental triggers. In Mexico, current governmental policies subsidize restoration efforts, to address ecological degradation caused by abandonments; however, there is a need for new approaches to assess their effectiveness. Addressing this, we explore a method to monitor and assess (1) land surface phenology trends in arid agro-ecosystems, and (2) the effect of climatic factors and restoration treatments on the phenology of abandoned agricultural fields. We used 16-day normalized difference vegetation index composites from the moderate resolution imaging spectroradiometer from 2000 to 2009 to derive seasonal phenometrics. We then derived phenoclimatic variables and land cover thematic maps, to serve as a set of independent factors that influence vegetation phenology. We conducted a multivariate analysis of variance to analyze phenological trends among land cover types, and developed multiple linear regression models to assess influential climatic factors driving phenology per land cover analyzed. Our results suggest that the start and length of the growing season had different responses to environmental factors depending on land cover type. Our analysis also suggests possible establishment of arid adapted species (from surrounding ecosystems) in abandoned fields with longer times since abandonment. Using this approach, we were able increase our understanding on how climatic factors influence phenology on degraded arid agro-ecosystems, and how this systems evolve after disturbance.
Disentangling Climate and Land-use Impacts on Grassland Carbon and Water Fluxes
NASA Astrophysics Data System (ADS)
Brunsell, N. A.; Nippert, J. B.
2014-12-01
Regional climate and land cover interact in a complex, non-linear manner to alter the local cycling of mass and energy. It is often difficult to isolate the role of either mechanism on the resultant fluxes. Here, we attempt to isolate these mechanisms through the use of network of 4 Ameriflux eddy covariance towers installed over different land cover and land use classes along a pronounced rainfall gradient. The land cover types include: annually burned C4 grassland, a 4 year burn site experiencing woody encroachment, an abandoned agricultural field and a new perennial agricultural site. We investigated the impact of rainfall variability, drought, and heat waves on the water and carbon budgets using data analysis, remote sensing, and modeling approaches. In addition, we have established a network of mini-meteorological stations at the annually and 4-year burn sites to assess micro-scale variability within the footprints of the towers as a function of topographic position, soil depth and soil water availability. Through the use of a wavelet multiscale decomposition and information theory metrics, we have isolated the role of environmental factors (temperature, humidity, soil moisture, etc.) on the fluxes across the different sites. By applying a similar analysis to model output, we can assess the ability of land-surface models to recreate the observed sensitity. Results indicate the utility of a network of measurement systems used in conjunction with land surface modeling and time series analysis to assess differential impacts to similar regional scale climate forcings. Implications for the role of land cover class in regional and global scale modeling systems will also be discussed.
NASA Astrophysics Data System (ADS)
Markfort, Corey D.; Resseger, Emily; Porté-Agel, Fernando; Stefan, Heinz
2014-05-01
Lakes with a surface area of less than 10 km2 account for over 50% of the global cumulative lake surface water area, and make up more than 99% of the total number of global lakes, ponds, and wetlands. Within the boreal regions as well as some temperate and tropical areas, a significant proportion of land cover is characterized by lakes or wetlands, which can have a dramatic effect on land-atmosphere fluxes as well as the local and regional energy budget. Many of these small water bodies are surrounded by complex terrain and forest, which cause the wind blowing over a small lake or wetland to be highly variable. Wind mixing of the lake surface layer affects thermal stratification, surface temperature and air-water gas transfer, e.g. O2, CO2, and CH4. As the wind blows from the land to the lake, wake turbulence behind trees and other shoreline obstacles leads to a recirculation zone and enhanced turbulence. This wake flow results in the delay of the development of wind shear stress on the lake surface, and the fetch required for surface shear stress to fully develop may be ~O(1 km). Interpretation of wind measurements made on the lake is hampered by the unknown effect of wake turbulence. We present field measurements designed to quantify wind variability over a sheltered lake. The wind data and water column temperature profiles are used to evaluate a new method to quantify wind sheltering of lakes that takes into account lake size, shape and the surrounding landscape features. The model is validated against field data for 36 Minnesota lakes. Effects of non-uniform sheltering and lake shape are also demonstrated. The effects of wind sheltering must be included in lake models to determine the effect of wind-derived energy inputs on lake stratification, surface gas transfer, lake water quality, and fish habitat. These effects are also important for correctly modeling momentum, heat, moisture and trace gas flux to the atmosphere.
Advances in land modeling of KIAPS based on the Noah Land Surface Model
NASA Astrophysics Data System (ADS)
Koo, Myung-Seo; Baek, Sunghye; Seol, Kyung-Hee; Cho, Kyoungmi
2017-08-01
As of 2013, the Noah Land Surface Model (LSM) version 2.7.1 was implemented in a new global model being developed at the Korea Institute of Atmospheric Prediction Systems (KIAPS). This land surface scheme is further refined in two aspects, by adding new physical processes and by updating surface input parameters. Thus, the treatment of glacier land, sea ice, and snow cover are addressed more realistically. Inconsistencies in the amount of absorbed solar flux at ground level by the land surface and radiative processes are rectified. In addition, new parameters are available by using 1-km land cover data, which had usually not been possible at a global scale. Land surface albedo/emissivity climatology is newly created using Moderate-Resolution Imaging Spectroradiometer (MODIS) satellitebased data and adjusted parameterization. These updates have been applied to the KIAPS-developed model and generally provide a positive impact on near-surface weather forecasting.
Evaluation of different field methods for measuring soil water infiltration
NASA Astrophysics Data System (ADS)
Pla-Sentís, Ildefonso; Fonseca, Francisco
2010-05-01
Soil infiltrability, together with rainfall characteristics, is the most important hydrological parameter for the evaluation and diagnosis of the soil water balance and soil moisture regime. Those balances and regimes are the main regulating factors of the on site water supply to plants and other soil organisms and of other important processes like runoff, surface and mass erosion, drainage, etc, affecting sedimentation, flooding, soil and water pollution, water supply for different purposes (population, agriculture, industries, hydroelectricity), etc. Therefore the direct measurement of water infiltration rates or its indirect deduction from other soil characteristics or properties has become indispensable for the evaluation and modelling of the previously mentioned processes. Indirect deductions from other soil characteristics measured under laboratory conditions in the same soils, or in other soils, through the so called "pedo-transfer" functions, have demonstrated to be of limited value in most of the cases. Direct "in situ" field evaluations have to be preferred in any case. In this contribution we present the results of past experiences in the measurement of soil water infiltration rates in many different soils and land conditions, and their use for deducing soil water balances under variable climates. There are also presented and discussed recent results obtained in comparing different methods, using double and single ring infiltrometers, rainfall simulators, and disc permeameters, of different sizes, in soils with very contrasting surface and profile characteristics and conditions, including stony soils and very sloping lands. It is concluded that there are not methods universally applicable to any soil and land condition, and that in many cases the results are significantly influenced by the way we use a particular method or instrument, and by the alterations in the soil conditions by the land management, but also due to the manipulation of the surface soil before and during the measurement. Due to the commonly found high variability, natural or induced by land management, of the soil surface and subsurface hydrological properties, and to the limitations imposed by the requirements of water for the measurements, there is proposed a simple and handy method, which do not use high volumes of water, adaptable to very different soil and land conditions, and that allow many repeated measurements with acceptable accuracy for most of the purposes. References Pla, I., 1997. A soil water balance model for monitoring soil erosion processes and effects on steep lands in the tropics. Soil Technology. 11(1):17-30. Elsevier Pla, I., 2006. Hydrological approach for assessing desertification processes in the Mediterranean region. In W.G. Kepner et al. (Editors), Desertification in the Mediterranean Region. A Security Issue. 579-600 Springer. Heidelberg (Germany) Reynolds W.D., B.T. Bowman, R.R. Brunke, C.F. Drury and C.S. Tan. 2000. Comparison of Tension Infiltrometer, Pressure Infiltrometer, and Soil Core Estimates of Saturated Hydraulic Conductivity . Soil Science Society of America Journal 64:478-484 Segal, E., S.A.Bradford, P. Shouse; N. Lazarovich, and D. Corwin. 2008. Integration of Hard and Soft Data to Characterize Field-Scale Hydraulic Properties for Flow and Transport Studies. Vadose Zone J 7:878-889 Young, E. 1991. Infiltration measurements, a review. Hydrological processes 5: 309-320.
NASA Technical Reports Server (NTRS)
Alexander, R. H. (Principal Investigator); Deforth, P. W.; Fitzpatrick, K. A.; Lins, H. F., Jr.; Mcginty, H. K., III
1975-01-01
The author has identified the following significant results. Level 2 land use mapping from high altitude aircraft photography at a scale of 1:100,000 required production of a photomosaic mapping base for each of the 48, 50 x 50 km sheets, and the interpretation and coding of land use polygons on drafting film overlays. To enhance the value of the land use sheets, a series of overlays was compiled, showing cultural features, county boundaries and census tracts, surface geology, and drainage basins. In producing level 1 land use maps from LANDSAT imagery, at a scale of 1:250,000 drafting film was directly overlaid on LANDSAT color composite transparencies. Numerous areas of change were identified, but extensive areas of false changes were also noted.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ssegane, Herbert; Negri, M. Cristina; Quinn, John
Current and future demand for food, feed, fiber, and energy require novel approaches to land management, which demands that multifunctional landscapes are created to integrate various ecosystem functions into a sustainable land use. We developed an approach to design such landscapes at a field scale to minimize concerns of land use change, water quality, and greenhouse gas emissions associated with production of food and bioenergy. This study leverages concepts of nutrient recovery and phytoremediation to place bioenergy crops on the landscape to recover nutrients released to watersheds by commodity crops. Crop placement is determined by evaluating spatial variability of: 1)more » soils, 2) surface flow pathways, 3) shallow groundwater flow gradients, 4) subsurface nitrate concentrations, and 5) primary crop yield. A 0.8 ha bioenergy buffer was designed within a 6.5 ha field to intercept concentrated surface flow, capture and use nitrate leachate, and minimize use of productive areas. Denitrification-Decomposition (DNDC) simulations show that on average, a switchgrass (Panicum Virgatum L.) or willow (Salix spp.) buffer within this catchment according to this design could reduce annual leached NO3 by 61 or 59% and N2O emission by 5.5 or 10.8%, respectively, produce 8.7 or 9.7 Mg ha-1 of biomass respectively, and displace 6.7 Mg ha-1 of corn (Zea mays L.) grain. Therefore, placement of bioenergy crops has the potential to increase environmental sustainability when the pairing of location and crop type result in minimal disruption of current food production systems and provides additional environmental benefits.« less
Ji, Gang; Xu, Ming-gang; Wen, Shi-lin; Wang, Bo-ren; Zhang, Lu; Liu, Li-sheng
2015-09-01
The characteristics of soil pH and exchangeable acidity in soil profile under different vegetation types were studied in hilly red soil regions of southern Hunan Province, China. The soil samples from red soil profiles within 0-100 cm depth at fertilized plots and unfertilized plots were collected and analyzed to understand the profile distribution of soil pH and exchangeable acidity. The results showed that, pH in 0-60 cm soil from the fertilized plots decreased as the following sequence: citrus orchard > Arachis hypogaea field > tea garden. As for exchangeable acidity content, the sequence was A. hypogaea field ≤ citrus orchard < tea garden. After tea tree and A. hypogaea were planted for long time, acidification occurred in surface soil (0-40 cm), compared with the deep soil (60-100 cm), and soil pH decreased by 0.55 and 0.17 respectively, but such changes did not occur in citrus orchard. Soil pH in 0-40 cm soil from the natural recovery vegetation unfertilized plots decreased as the following sequence: Imperata cylindrica land > Castanea mollissima garden > Pinus elliottii forest ≥ Loropetalum chinensis forest. As for exchangeable acidity content, the sequence was L cylindrica land < C. mollissima garden < L. chinensis forest ≤ P. elliottii forest. Soil pH in surface soil (0-20 cm) from natural forest plots, secondary forest and Camellia oleifera forest were significantly lower than that from P. massoniana forest, decreased by 0.34 and 0.20 respectively. For exchangeable acidity content in 0-20 cm soil from natural forest plot, P. massoniana forest and secondary forest were significantly lower than C. oleifera forest. Compared with bare land, surface soil acidification in unfertilized plots except I. cylindrica land had been accelerated, and the natural secondary forest was the most serious among them, with surface soil pH decreasing by 0.52. However, the pH increased in deep soils from unfertilized plots except natural secondary forest, and I. cylindrica land was the most obvious among them, with soil pH increasing by 0.43. The effects of fertilization and vegetation type on pH and exchangeable acidity decreased with the increasing soil depth from all plots.
Communicating why land surface heterogeneity matters
NASA Astrophysics Data System (ADS)
Tague, C.; Burke, W.; Bart, R. R.; Turpin, E.; Wood, T.; Gordon, D.
2017-12-01
As hydrologic scientists, we know that land surface heterogeneity can have nuanced and sometimes dramatic impacts on the water cycle. Land surface characteristics, including the structure and composition of vegetation and soil storage and drainage properties, alter how incoming precipitation is translated into streamflow and evapotranspiration. Land surface heterogeneity can explain why this partitioning of incoming precipitation cannot always be computed by a simple water budget calculation. We also know that land surface characteristics are dynamic - vegetation grows and changes with fire, disease and human actions and these changes will alter the partitioning of water - how much so, however depends itself on other site characteristics - soil water storage and the timing and magnitude of precipitation. This complex impact of space-time dynamics on the water cycle is something we need to effectively communicate to non-experts. For example, we may want to explain why sometimes forest management practices increase water availability but sometimes they don't - or why the impacts of urbanization or fire are location specific. If we do not communicate these dependencies we risk over-simplifying and eroding scientific credibility when observed effects don't match simple generalizations. On the other hand excessive detail can overwhelm and disengage audiences. So how do we help different communities public, private landowners, other scientists, NGOs, governments to better understand the role of space-time heterogeneity. To address this issue, we present some results from ongoing work that looks at the impact of fuel treatment of forest ecohydrology. This work stem from a collaboration between an ecohydrologic modeling team, social-scientists, a visual artist and compute graphics students. We use a coupled model, validated with field measurements, to show why spatial heterogeneity matters for understanding the impact of fuel treatments on the water cycle for the Sierra Critical Zone Observatory. We summarize current findings and present initial designs for translating these science based results into interactive visualization and conceptual art installations with the goal of better communicating the different components of landscape heterogeneity and why it matters
NASA Astrophysics Data System (ADS)
Lathuilliere, M. J.; Dalmagro, H. J.; Black, T. A.; Arruda, P. H. Z. D.; Hawthorne, I.; Couto, E. G.; Johnson, M. S.
2017-12-01
Southern Amazonia, Brazil, is home to a rapidly expanding agricultural frontier in which tropical forest and savanna landscapes have been increasingly replaced by agricultural land since the 1990s. One important impact of deforestation is the reduction in water vapour transferred to the atmosphere via evapotranspiration (ET) from rainfed agriculture landscapes compared to natural vegetation, leading to a reduction in regional precipitation recycling. Here, we discuss land and water management choices for future agricultural production in Southern Amazonia and their potential effects on the atmospheric water cycle. We illustrate these choices by presenting ET measurements on an agricultural landscape by eddy covariance (EC) between September 2015 and February 2017. Measurements were made for two fields adjacent to one micrometeorological EC tower: (1) one rainfed field containing a succession of soybean, maize, brachiara and soybean, and (2) one irrigated field with a succession of soybean, rice, beans, and soybean. Over the time period, total ET in the rainfed and irrigated fields was 1266 ± 294 mm and 1415 ± 180 mm, respectively for a total precipitation of 3099 mm. The main difference in ET between the fields was attributed to the application of 118 mm of surface water irrigated for bean production in the irrigated field between June and September 2016. In the rainfed field, soybean ET was 332 ± 82 mm (2015-2016) and 423 ± 99 mm (2016-2017) for 824 mm and 1124 mm of precipitation, respectively. In the irrigated field, soybean ET was 271 ± 38 mm (2015) and 404 ± 60 mm (2016-2017) with supplemental irrigation added in 2015. Our results illustrate how supplemental irrigation can favour early soybean planting while transferring additional water vapour to the atmosphere at levels similar to natural vegetation. We conclude by discussing our results in the context of future land and water trade-offs for agricultural intensification in Brazil's "arc-of-deforestation".
Douglas L. Sisterson
1977-01-01
Data collected on 26 July 1974 as a part of project METROMEX in St. Louis show the three-dimensional structure of the urban moisture field. Mesoscale dry regions at the urban surface, corresponding to large residential and light industrial land-use characterization, were responsible for a reduction in specific humidity in the urban mixing layer. Anthropogenic sources...
USDA-ARS?s Scientific Manuscript database
Soil moisture is a key variable in understanding the hydrologic processes and energy fluxes at the land surface. In spite of new technologies for in-situ soil moisture measurements and increased availability of remotely sensed soil moisture data, scaling issues between soil moisture observations and...
Curve numbers for long-term no-till corn and agricultural practices with high watershed infiltration
USDA-ARS?s Scientific Manuscript database
The Curve Number (CN) method is an engineering and land management tool for estimating surface runoff from rainstorms. There are few watershed runoff records available during which a no-till crop was growing and hence there are few field-measured CN values. We investigated CN under continuous long-...
USDA-ARS?s Scientific Manuscript database
Thermal-infrared remote sensing of land surface temperature provides valuable information for quantifying root-zone water availability, evapotranspiration (ET) and crop condition. A thermal-based scheme, called the Two-Source Energy Balance (TSEB) model, solves for the soil/substrate and canopy temp...
Noble, J.E.; Bush, P.W.; Kasmarek, M.C.; Barbie, D.L.
1996-01-01
In 1989, the U.S. Geological Survey, in cooperation with the Harris-Galveston Coastal Subsidence District, began a field study to determine the depth to the water table and to estimate the rate of recharge in outcrops of the Chicot and Evangeline aquifers near Houston, Texas. The study area comprises about 2,000 square miles of outcrops of the Chicot and Evangeline aquifers in northwest Harris County, Montgomery County, and southern Walker County. Because of the scarcity of measurable water-table wells, depth to the water table below land surface was estimated using a surface geophysical technique, seismic refraction. The water table in the study area generally ranges from about 10 to 30 foot below land surface and typically is deeper in areas of relatively high land-surface altitude than in areas of relatively low land- surface altitude. The water table has demonstrated no long-term trends since ground-water development began, with the probable exception of the water table in the Katy area: There the water table is more than 75 feet deep, probably due to ground-water pumpage from deeper zones. An estimated rate of recharge in the aquifer outcrops was computed using the interface method in which environmental tritium is a ground-water tracer. The estimated average total recharge rate in the study area is 6 inches per year. This rate is an upper bound on the average recharge rate during the 37 years 1953-90 because it is based on the deepest penetration (about 80 feet) of postnuclear-testing tritium concentrations. The rate, which represents one of several components of a complex regional hydrologic budget, is considered reasonable but is not definitive because of uncertainty regarding the assumptions and parameters used in its computation.
Improved assessment of gross and net primary productivity of Canada's landmass
NASA Astrophysics Data System (ADS)
Gonsamo, Alemu; Chen, Jing M.; Price, David T.; Kurz, Werner A.; Liu, Jane; Boisvenue, Céline; Hember, Robbie A.; Wu, Chaoyang; Chang, Kuo-Hsien
2013-12-01
assess Canada's gross primary productivity (GPP) and net primary productivity (NPP) using boreal ecosystem productivity simulator (BEPS) at 250 m spatial resolution with improved input parameter and driver fields and phenology and nutrient release parameterization schemes. BEPS is a process-based two-leaf enzyme kinetic terrestrial ecosystem model designed to simulate energy, water, and carbon (C) fluxes using spatial data sets of meteorology, remotely sensed land surface variables, soil properties, and photosynthesis and respiration rate parameters. Two improved key land surface variables, leaf area index (LAI) and land cover type, are derived at 250 m from Moderate Resolution Imaging Spectroradiometer sensor. For diagnostic error assessment, we use nine forest flux tower sites where all measured C flux, meteorology, and ancillary data sets are available. The errors due to input drivers and parameters are then independently corrected for Canada-wide GPP and NPP simulations. The optimized LAI use, for example, reduced the absolute bias in GPP from 20.7% to 1.1% for hourly BEPS simulations. Following the error diagnostics and corrections, daily GPP and NPP are simulated over Canada at 250 m spatial resolution, the highest resolution simulation yet for the country or any other comparable region. Total NPP (GPP) for Canada's land area was 1.27 (2.68) Pg C for 2008, with forests contributing 1.02 (2.2) Pg C. The annual comparisons between measured and simulated GPP show that the mean differences are not statistically significant (p > 0.05, paired t test). The main BEPS simulation error sources are from the driver fields.
Environmental assessment of creosote-treated pilings in the marine environment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Butala, J.H.; Webb, D.A.; Jop, K.M.
1995-12-31
A comprehensive ecological risk assessment was conducted to evaluate the environmental impact of creosote-treated pilings in the marine environment at Moss Landing Harbor, Moss Landing, California. Four areas of investigation comprising the risk assessment were (1) evaluation of environmental conditions around existing creosote-treated pilings (2) investigating effects related to restoration of pilings (3) assessing creosote migration into surrounding environment, one year after pile-driving and (4) confirmation of creosote toxicity in laboratory studies. Biological and chemical evaluation of the impact of creosote-treated pilings was conducted on surface sheen, water column and sediment samples collected at Moss Landing Harbor. Water samples (surfacemore » sheen, water column and sediment pore water) were evaluated using short-term chronic exposures with Mysidopsis bahia, while bulk sediment samples were evaluated with 10-day sediment toxicity tests with Ampelisca abdita. Samples of surface, column water and sediment were analyzed for the constituents of creosote by GC mass spectrometry. In addition, a sample of neat material used to preserve treated pilings represented a reference for the polyaromatic hydrocarbons. Verification of organism response and analyses of field collected samples was performed by conducting 10-day A. abdita sediment and 7-day M. bahia elutriate exposures with creosote applied to clean sediment collected at Moss Landing, Evaluations were also performed to determine the effects of photoinduced toxicity on test organisms exposed to PAHs. The biological and analytical results of the field and laboratory exposures are being used to evaluate and determine risk of creosote-treated pilings on the marine environment.« less
Application of Satellite Gravimetry for Water Resource Vulnerability Assessment
NASA Technical Reports Server (NTRS)
Rodell, Matthew
2012-01-01
The force of Earth's gravity field varies in proportion to the amount of mass near the surface. Spatial and temporal variations in the gravity field can be measured via their effects on the orbits of satellites. The Gravity Recovery and Climate Experiment (GRACE) is the first satellite mission dedicated to monitoring temporal variations in the gravity field. The monthly gravity anomaly maps that have been delivered by GRACE since 2002 are being used to infer changes in terrestrial water storage (the sum of groundwater, soil moisture, surface waters, and snow and ice), which are the primary source of gravity variability on monthly to decadal timescales after atmospheric and oceanic circulation effects have been removed. Other remote sensing techniques are unable to detect water below the first few centimeters of the land surface. Conventional ground based techniques can be used to monitor terrestrial water storage, but groundwater, soil moisture, and snow observation networks are sparse in most of the world, and the countries that do collect such data rarely are willing to share them. Thus GRACE is unique in its ability to provide global data on variations in the availability of fresh water, which is both vital to life on land and vulnerable to climate variability and mismanagement. This chapter describes the unique and challenging aspects of GRACE terrestrial water storage data, examples of how the data have been used for research and applications related to fresh water vulnerability and change, and prospects for continued contributions of satellite gravimetry to water resources science and policy.
2014-04-30
CAPE CANAVERAL, Fla. – A technician vents off the gas from the propellant lines of NASA's Project Morpheus prototype lander after it completed a free-flight test at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The 98-second test began at 1:57 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending more than 800 feet at a peak speed of 36 mph. The vehicle, with its recently installed autonomous landing and hazard avoidance technology, or ALHAT, sensors surveyed the hazard field to determine safe landing sites. Morpheus then flew forward and downward covering approximately 1300 feet while performing a 78-foot divert to simulate a hazard avoidance maneuver. The lander descended and landed on a dedicated pad inside the ALHAT hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, which are green propellants. These new capabilities could be used in future efforts to deliver cargo to planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-04-30
CAPE CANAVERAL, Fla. – Technicians vent off the gas from the propellant lines of NASA's Project Morpheus prototype lander after it completed a free-flight test at the north end of the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The 98-second test began at 1:57 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending more than 800 feet at a peak speed of 36 mph. The vehicle, with its recently installed autonomous landing and hazard avoidance technology, or ALHAT, sensors surveyed the hazard field to determine safe landing sites. Morpheus then flew forward and downward covering approximately 1300 feet while performing a 78-foot divert to simulate a hazard avoidance maneuver. The lander descended and landed on a dedicated pad inside the ALHAT hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, which are green propellants. These new capabilities could be used in future efforts to deliver cargo to planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
Edwards, M; Topp, E; Metcalfe, C D; Li, H; Gottschall, N; Bolton, P; Curnoe, W; Payne, M; Beck, A; Kleywegt, S; Lapen, D R
2009-07-01
Land application of municipal biosolids can be a source of environmental contamination by pharmaceutical and personal care products (PPCPs). This study examined PPCP concentrations/temporally discrete mass loads in agricultural tile drainage systems where two applications of biosolids had previously taken place. The field plots received liquid municipal biosolids (LMB) in the fall of 2005 at an application rate of approximately 93,500 L ha (-1), and a second land application was conducted using dewatered municipal biosolids (DMB) applied at a rate of approximately 8Mg dw ha (-1) in the summer of 2006 [corrected].The DMB land application treatments consisted of direct injection (DI) of the DMB beneath the soil surface at a nominal depth of approximately 0.11 m, and surface spreading (SS) plus subsequent tillage incorporation of DMB in the topsoil (approximately 0.10 m depth). The PPCPs examined included eight pharmaceuticals (acetaminophen, fluoxetine, ibuprofen, gemfibrozil, naproxen, carbamazepine, atenolol, sulfamethoxazole), the nicotine metabolite cotinine, and two antibacterial personal care products triclosan and triclocarban. Residues of naproxen, cotinine, atenolol and triclosan originating from the fall 2005 LMB application were detected in tile water nearly nine months after application (triclocarban was not measured in 2005). There were no significant differences (p>0.05) in PPCP mass loads among the two DMB land application treatments (i.e., SS vs. DI); although, average PPCP mass loads late in the study season (>100 days after application) were consistently higher for the DI treatment relative to the SS treatment. While the concentration of triclosan (approximately 14,000 ng g(-1) dw) in DMB was about twice that of triclocarban (approximately 8000 ng g(-1) dw), the average tile water concentrations for triclosan were much higher (43+/-5 ng L(-1)) than they were for triclocarban (0.73+/-0.14 ng L(-1)). Triclosan concentrations (maximum observed in 2006 approximately 235 ng L(-1)) in tile water resulting from land applications may warrant attention from a toxicological perspective.
NASA Technical Reports Server (NTRS)
Hirsch, Annette L.; Kala, Jatin; Pitman, Andy J.; Carouge, Claire; Evans, Jason P.; Haverd, Vanessa; Mocko, David
2014-01-01
The authors use a sophisticated coupled land-atmosphere modeling system for a Southern Hemisphere subdomain centered over southeastern Australia to evaluate differences in simulation skill from two different land surface initialization approaches. The first approach uses equilibrated land surface states obtained from offline simulations of the land surface model, and the second uses land surface states obtained from reanalyses. The authors find that land surface initialization using prior offline simulations contribute to relative gains in subseasonal forecast skill. In particular, relative gains in forecast skill for temperature of 10%-20% within the first 30 days of the forecast can be attributed to the land surface initialization method using offline states. For precipitation there is no distinct preference for the land surface initialization method, with limited gains in forecast skill irrespective of the lead time. The authors evaluated the asymmetry between maximum and minimum temperatures and found that maximum temperatures had the largest gains in relative forecast skill, exceeding 20% in some regions. These results were statistically significant at the 98% confidence level at up to 60 days into the forecast period. For minimum temperature, using reanalyses to initialize the land surface contributed to relative gains in forecast skill, reaching 40% in parts of the domain that were statistically significant at the 98% confidence level. The contrasting impact of the land surface initialization method between maximum and minimum temperature was associated with different soil moisture coupling mechanisms. Therefore, land surface initialization from prior offline simulations does improve predictability for temperature, particularly maximum temperature, but with less obvious improvements for precipitation and minimum temperature over southeastern Australia.
NASA Astrophysics Data System (ADS)
Zhang, J.; Okin, G.
2016-12-01
Rangelands provide a variety of important ecosystem goods and services across drylands globally. They are also the most important emitters of dust across the globe. Field data collection based on points does not represent spatially continuous information about surface variables and, given the vast size of the world's rangelands, cannot cover even a small fraction of their area. Remote sensing is potentially a labor- and time-saving method to observe important rangeland vegetation variables at both temporal and spatial scales. Information on vegetation cover, bare gap size, and plant height provide key rangeland vegetation variables in arid and semiarid rangelands, in part because they strongly impact dust emission and determine wildlife habitat characteristics. This study reports on relationships between remote sensing in the reflected solar spectrum and field measures related to these three variables, and shows how these relationships can be extended to produce spatially and temporally continuous datasets coupled with quantitative estimates of error. Field data for this study included over 3,800 Assessment, Inventory, and Monitoring (AIM) measurements on Bureau of Land Management (BLM) lands throughout the western US. Remote sensing data were derived from MODIS nadir BRDF-adjusted reflectance (NBAR) and Landsat 8 OLI surface reflectance. Normalized bare gap size, total foliar cover, herbaceous cover and herbaceous height exhibit the greatest predictability from remote sensing variables with physically-reasonable relationships between remote sensing variables and field measures. Data fields produced using these relationships across the western US exhibit good agreement with independent high-resolution imagery.
NASA Astrophysics Data System (ADS)
Song, Z.; Lee, S. K.; Wang, C.; Kirtman, B. P.; Qiao, F.
2016-02-01
In order to identify and quantify intrinsic errors in the atmosphere-land and ocean-sea ice model components of the Community Earth System Model version 1 (CESM1) and their contributions to the tropical Atlantic sea surface temperature (SST) bias in CESM1, we propose a new method of diagnosis and apply it to a set of CESM1 simulations. Our analyses of the model simulations indicate that both the atmosphere-land and ocean-sea ice model components of CESM1 contain large errors in the tropical Atlantic. When the two model components are fully coupled, the intrinsic errors in the two components emerge quickly within a year with strong seasonality in their growth rates. In particular, the ocean-sea ice model contributes significantly in forcing the eastern equatorial Atlantic warm SST bias in early boreal summer. Further analysis shows that the upper thermocline water underneath the eastern equatorial Atlantic surface mixed layer is too warm in a stand-alone ocean-sea ice simulation of CESM1 forced with observed surface flux fields, suggesting that the mixed layer cooling associated with the entrainment of upper thermocline water is too weak in early boreal summer. Therefore, although we acknowledge the potential importance of the westerly wind bias in the western equatorial Atlantic and the low-level stratus cloud bias in the southeastern tropical Atlantic, both of which originate from the atmosphere-land model, we emphasize here that solving those problems in the atmosphere-land model alone does not resolve the equatorial Atlantic warm bias in CESM1.
Ma, H. -Y.; Chuang, C. C.; Klein, S. A.; ...
2015-11-06
Here, we present an improved procedure of generating initial conditions (ICs) for climate model hindcast experiments with specified sea surface temperature and sea ice. The motivation is to minimize errors in the ICs and lead to a better evaluation of atmospheric parameterizations' performance in the hindcast mode. We apply state variables (horizontal velocities, temperature and specific humidity) from the operational analysis/reanalysis for the atmospheric initial states. Without a data assimilation system, we apply a two-step process to obtain other necessary variables to initialize both the atmospheric (e.g., aerosols and clouds) and land models (e.g., soil moisture). First, we nudge onlymore » the model horizontal velocities towards operational analysis/reanalysis values, given a 6-hour relaxation time scale, to obtain all necessary variables. Compared to the original strategy in which horizontal velocities, temperature and specific humidity are nudged, the revised approach produces a better representation of initial aerosols and cloud fields which are more consistent and closer to observations and model's preferred climatology. Second, we obtain land ICs from an offline land model simulation forced with observed precipitation, winds, and surface fluxes. This approach produces more realistic soil moisture in the land ICs. With this refined procedure, the simulated precipitation, clouds, radiation, and surface air temperature over land are improved in the Day 2 mean hindcasts. Following this procedure, we propose a “Core” integration suite which provides an easily repeatable test allowing model developers to rapidly assess the impacts of various parameterization changes on the fidelity of modelled cloud-associated processes relative to observations.« less
NASA Astrophysics Data System (ADS)
Ma, H.-Y.; Chuang, C. C.; Klein, S. A.; Lo, M.-H.; Zhang, Y.; Xie, S.; Zheng, X.; Ma, P.-L.; Zhang, Y.; Phillips, T. J.
2015-12-01
We present an improved procedure of generating initial conditions (ICs) for climate model hindcast experiments with specified sea surface temperature and sea ice. The motivation is to minimize errors in the ICs and lead to a better evaluation of atmospheric parameterizations' performance in the hindcast mode. We apply state variables (horizontal velocities, temperature, and specific humidity) from the operational analysis/reanalysis for the atmospheric initial states. Without a data assimilation system, we apply a two-step process to obtain other necessary variables to initialize both the atmospheric (e.g., aerosols and clouds) and land models (e.g., soil moisture). First, we nudge only the model horizontal velocities toward operational analysis/reanalysis values, given a 6 h relaxation time scale, to obtain all necessary variables. Compared to the original strategy in which horizontal velocities, temperature, and specific humidity are nudged, the revised approach produces a better representation of initial aerosols and cloud fields which are more consistent and closer to observations and model's preferred climatology. Second, we obtain land ICs from an off-line land model simulation forced with observed precipitation, winds, and surface fluxes. This approach produces more realistic soil moisture in the land ICs. With this refined procedure, the simulated precipitation, clouds, radiation, and surface air temperature over land are improved in the Day 2 mean hindcasts. Following this procedure, we propose a "Core" integration suite which provides an easily repeatable test allowing model developers to rapidly assess the impacts of various parameterization changes on the fidelity of modeled cloud-associated processes relative to observations.
NASA Astrophysics Data System (ADS)
Gochis, D. J.; Gutmann, E. D.; Brooks, P. D.; Reed, D. E.; Ewers, B. E.; Pendall, E.; Biederman, J. A.; Harpold, A. A.; Barnard, H. R.; Hu, J.
2011-12-01
Forest dynamics induced by insect infestation can have a significant, local impact on plant physiological regulation of water, energy and carbon fluxes. Rapid mortality succeeded by more gradually varying land cover changes are presently thought to initiate a cascade of changes to water, energy and carbon budgets at the forest stand scale. Initial model sensitivity results have suggested very strong changes in land-atmosphere exchanges of these variables. Specifically, model results from the Noah land surface model, a relatively simple model, have suggested that loss of transpiration function may result in a nearly 50% increase in seasonal soil moisture values and similar increases in runoff production for locations in the central Rocky Mountains. However, differing model structures, such as the representation of plant canopy architecture, snowpack dynamics, dynamic vegetation and hillslope hydrologic processes, may significantly confound the synthesis of results from different modeling systems. We assess the performance of new suite of model simulations from three different land surface models of differing model structures and complexity levels against a comprehensive set of field observations of land surface flux and state variables. The focus of the analysis is in diagnosing how model structure influences changes in energy, water and carbon budget partitioning prior to and following insect infestation. Specific emphasis in this presentation is placed on verifying variables that characterize top of canopy and within canopy energy and water fluxes. We conclude the presentation with a set of recommendations about the advantages and disadvantages of various model structures in their simulation of insect driven forest dynamics.
Brown, Robert D.; Wolfe, Edward W.
1970-01-01
This strip map is one of a series of maps showing recently active fault breaks along the San Andreas and other active faults in California. It is designed to inform persons who are concerned with land use near the fault of the location of those fault breaks that have moved recently. The lines on the map are lines of rupture and creep that can be identified by field evidence and that clearly affect the present surface of the land. Map users should keep in mind that these lines are intended primarily as guides to help locate the fault; the mapped lines are not necessarily shown with the precision demanded by some engineering or land utilization needs.
Carbon-Water-Energy Relations for Selected River Basins
NASA Technical Reports Server (NTRS)
Choudhury, B. J.
1998-01-01
A biophysical process-based model was run using satellite, assimilated and ancillary data for four years (1987-1990) to calculate components of total evaporation (transpiration, interception, soil and snow evaporation), net radiation, absorbed photosynthetically active radiation and net primary productivity over the global land surface. Satellite observations provided fractional vegetation cover, solar and photosynthetically active radiation incident of the surface, surface albedo, fractional cloud cover, air temperature and vapor pressure. The friction velocity and surface air pressure are obtained from a four dimensional data assimilation results, while precipitation is either only surface observations or a blended product of surface and satellite observations. All surface and satellite data are monthly mean values; precipitation has been disaggregated into daily values. All biophysical parameters of the model are prescribed according to published records. From these global land surface calculations results for river basins are derived using digital templates of basin boundaries. Comparisons with field observations (micrometeorologic, catchment water balance, biomass production) and atmospheric water budget analysis for monthly evaporation from six river basins have been done to assess errors in the calculations. Comparisons are also made with previous estimates of zonal variations of evaporation and net primary productivity. Efficiencies of transpiration, total evaporation and radiation use, and evaporative fraction for selected river basins will be presented.
Land Surface Temperature Measurements from EOS MODIS Data
NASA Technical Reports Server (NTRS)
Wan, Zheng-Ming
2004-01-01
This report summarizes the accomplishments made by the MODIS LST (Land-Surface Temperature) group at University of California, Santa Barbara, under NASA Contract. Version 1 of the MODIS Land-Surface Temperature Algorithm Theoretical Basis Document (ATBD) was reviewed in June 1994, version 2 reviewed in November 1994, version 3.1 in August 1996, and version 3.3 updated in April 1999. Based on the ATBD, two LST algorithms were developed, one is the generalized split-window algorithm and another is the physics-based day/night LST algorithm. These two LST algorithms were implemented into the production generation executive code (PGE 16) for the daily standard MODIS LST products at level-2 (MODII-L2) and level-3 (MODIIA1 at 1 km resolution and MODIIB1 at 5km resolution). PGE codes for 8-day 1 km LST product (MODIIA2) and the daily, 8-day and monthly LST products at 0.05 degree latitude/longitude climate model grids (CMG) were also delivered. Four to six field campaigns were conducted each year since 2000 to validate the daily LST products generated by PGE16 and the calibration accuracies of the MODIS TIR bands used for the LST/emissivity retrieval from versions 2-4 of Terra MODIS data and versions 3-4 of Aqua MODIS data. Validation results from temperature-based and radiance-based methods indicate that the MODIS LST accuracy is better than 1 C in most clear-sky cases in the range from -10 to 58 C. One of the major lessons learn from multi- year temporal analysis of the consistent V4 daily Terra MODIS LST products in 2000-2003 over some selected target areas including lakes, snow/ice fields, and semi-arid sites is that there are variable numbers of cloud-contaminated LSTs in the MODIS LST products depending on surface elevation, land cover types, and atmospheric conditions. A cloud-screen scheme with constraints on spatial and temporal variations in LSTs was developed to remove cloud-contaminated LSTs. The 5km LST product was indirectly validated through comparisons to the 1 km LST product. Twenty three papers related to the LST research work were published in journals over the last decade.
NASA Astrophysics Data System (ADS)
Turner, Andrew; Bhat, Ganapati; Evans, Jonathan; Madan, Ranju; Marsham, John; Martin, Gill; Mitra, Ashis; Mrudula, Gm; Parker, Douglas; Pattnaik, Sandeep; Rajagopal, En; Taylor, Christopher; Tripathi, Sachchida
2017-04-01
The INCOMPASS project uses data from a field and aircraft measurement campaign during the 2016 monsoon onset to better understand and predict monsoon rainfall. The monsoon supplies the majority of water in South Asia, however modelling and forecasting the monsoon from days to the season ahead is limited by large model errors that develop quickly. Likely problems lie in physical parametrizations such as convection, the boundary layer and land surface. At the same time, lack of detailed observations prevents more thorough understanding of monsoon circulation and its interaction with the land surface; a process governed by boundary layer and convective cloud dynamics. From May to July 2016, INCOMPASS used a modified BAe-146 jet aircraft operated by the UK Facility for Airborne Atmospheric Measurements (FAAM), for the first project of this scale in India. The India and UK team flew around 100 hours of science sorties from bases in northern and southern India. Flights from Lucknow in the northern plains took measurements to the west and southeast to allow sampling of the complete contrast from dry desert air to the humid environment over the north Bay of Bengal. These routes were repeated in the pre-monsoon and monsoon phases, measuring contrasting surface and boundary layer structures. In addition, flights from the southern base in Bengaluru measured contrasts from the Arabian Sea, across the intense rains of the Western Ghats mountains, over the rain shadow in southeast India and over the southern Bay of Bengal. Flight planning was performed with the aid of forecasts from a new UK Met Office 4km limited area model. INCOMPASS also installed a network of surface flux towers, as well as operating a cloud-base ceilometer and performing intensive radiosonde launches from a supersite in Kanpur. Here we will outline preliminary results from the field campaign including new observations of the surface, boundary layer structure and atmospheric profiles from aircraft data. We also include initial results from nested high-resolution modelling experiments of the 2016 monsoon, at a resolution of 4km in comparison with bespoke regional forecasts run throughout the field campaign.
Sensitivity of river discharge to the quality of external meteorological forcings
NASA Astrophysics Data System (ADS)
Materia, S.; Dirmeyer, P.; Guo, Z.; Alessandri, A.; Navarra, A.
2009-09-01
Large-scale river routing models are essential tools to close the hydrological cycle in fully coupled climate models. Moreover, the availability of a realistic routing scheme is a powerful instrument to assess the validity of land surface parameterization, which has been recognized to be a crucial component of the global climate. This study is dedicated to assess the sensitivity of river discharge to the variation of external meteorological forcing. The Land Surface Scheme created at the Center for Ocean, Land and Atmosphere Studies (COLA), the SSiB model, was constrained with different meteorological fields. The resulting surface and sub-surface runoffs were used as forcing data for the HD River Routing Scheme. As expected, river flow is mainly sensitive to precipitation variability, but changes in radiative forcing affect discharge as well, presumably due to the interaction with evaporation. Also, this analysis provided an estimate of the sensitivity of river discharge to precipitation variations. A few areas, like Central and Eastern Asia, Southern and Central Europe and the majority of the US, show a magnified response of river discharge to a given percentage change in precipitation. Hence, an amplified effect of droughts following the reduction in precipitation, as it is indicated by many climate scenarios, may occur in places such as the Mediterranean. Conversely, increasing summer precipitation foreseen in Southern and Eastern Asia may amplify floods in one the poorest and most populated regions in the world. These results can be used for the definition and assessment of new strategies for land use and water management in the near future.
Mapping gullies, dunes, lava fields, and landslides via surface roughness
NASA Astrophysics Data System (ADS)
Korzeniowska, Karolina; Pfeifer, Norbert; Landtwing, Stephan
2018-01-01
Gully erosion is a widespread and significant process involved in soil and land degradation. Mapping gullies helps to quantify past, and anticipate future, soil losses. Digital terrain models offer promising data for automatically detecting and mapping gullies especially in vegetated areas, although methods vary widely measures of local terrain roughness are the most varied and debated among these methods. Rarely do studies test the performance of roughness metrics for mapping gullies, limiting their applicability to small training areas. To this end, we systematically explored how local terrain roughness derived from high-resolution Light Detection And Ranging (LiDAR) data can aid in the unsupervised detection of gullies over a large area. We also tested expanding this method for other landforms diagnostic of similarly abrupt land-surface changes, including lava fields, dunes, and landslides, as well as investigating the influence of different roughness thresholds, resolutions of kernels, and input data resolution, and comparing our method with previously published roughness algorithms. Our results show that total curvature is a suitable metric for recognising analysed gullies and lava fields from LiDAR data, with comparable success to that of more sophisticated roughness metrics. Tested dunes or landslides remain difficult to distinguish from the surrounding landscape, partly because they are not easily defined in terms of their topographic signature.
NASA Astrophysics Data System (ADS)
Thomas, R. Q.; Zaehle, S.; Templer, P. H.; Goodale, C. L.
2011-12-01
Predictions of climate change depend on accurately modeling the feedbacks among the carbon cycle, nitrogen cycle, and climate system. Several global land surface models have shown that nitrogen limitation determines how land carbon fluxes respond to rising CO2, nitrogen deposition, and climate change, thereby influencing predictions of climate change. However, the magnitude of the carbon-nitrogen-climate feedbacks varies considerably by model, leading to critical and timely questions of why they differ and how they compare to field observations. To address these questions, we initiated a model inter-comparison of spatial patterns and drivers of nitrogen limitation. The experiment assessed the regional consequences of sustained nitrogen additions in a set of 25-year global nitrogen fertilization simulations. The model experiments were designed to cover effects from small changes in nitrogen inputs associated with plausible increases in nitrogen deposition to large changes associated with field-based nitrogen fertilization experiments. The analyses of model simulations included assessing the geographically varying degree of nitrogen limitation on plant and soil carbon cycling and the mechanisms underlying model differences. Here, we present results from two global land-surface models (CLM-CN and O-CN) with differing approaches to modeling carbon-nitrogen interactions. The predictions from each model were compared to a set of globally distributed observational data that includes nitrogen fertilization experiments, 15N tracer studies, small catchment nitrogen input-output studies, and syntheses across nitrogen deposition gradients. Together these datasets test many aspects of carbon-nitrogen coupling and are able to differentiate between the two models. Overall, this study is the first to explicitly benchmark carbon and nitrogen interactions in Earth System Models using a range of observations and is a foundation for future inter-comparisons.
NASA Astrophysics Data System (ADS)
Richter, D., Jr.; Mobley, M. L.; Billings, S. A.; Markewitz, D.
2016-12-01
At the Calhoun Long-Term Soil-Ecosystem field experiment (1957-present), reforestation of previously cultivated land over fifty years nearly doubled soil organic carbon (SOC) in surface soils (0 to 7.5-cm) but these gains were offset by significant SOC losses in subsoils (35 to 60-cm). Nearly all of the accretions in surface soils amounted to gains in light fraction SOC, whereas losses at depth were associated with silt and clay-sized particles. These changes are documented in the Calhoun Long-Term Soil-Ecosystem (LTSE) study that resampled soil from 16 plots about every five years and archived all soil samples from four soil layers within the upper 60-cm of mineral soil. We combined soil bulk density, density fractionation, stable isotopes, and radioisotopes to explore changes in SOC and soil organic nitrogen (SON) associated with five decades of the growth of a loblolly pine secondary forest. Isotopic signatures showed relatively large accumulations of contemporary forest-derived carbon in surface soils, and no accumulation of forest-derived carbon in subsoils. We interpret results to indicate that land-use change from cotton fields to secondary pine forests drove soil biogeochemical and hydrological changes that enhanced root and microbial activity and SOM decomposition in subsoils. As pine stands matured and are now transitioning to mixed pines and hardwoods, demands on soil organic matter for nutrients to support aboveground growth has eased due to pine mortality, and bulk SOM and SON and their isotopes in subsoils have stabilized. We anticipate major changes in the next fifty years as 1957 pine trees transition to hardwoods. This study emphasizes the importance of long-term experiments and deep soil measurements when characterizing SOC and SON responses to land use change. There is a remarkable paucity of E long-term soil data deeper than 30 cm.
NASA Astrophysics Data System (ADS)
Dusabimana, M. R.; Blach, D.; Mwiza, F.; Muzungu, E.; Swaminathan, R.; Tate, Z.
2014-12-01
Rwanda, a small country with the highest population density in Sub-Saharan Africa, is one of the world's poorest countries. Although agriculture is the backbone of Rwandan economy, agricultural productivity is extremely low. Over 90 % of the population is engaged in subsistence farming and only 52 % of the total land surface area is arable. Of this land, approximately 165,000 hectares are marshlands, of which only 57 % has been cultivated. Rwandan government has invested in the advancement of agriculture with activities such as irrigation, marshland reclamation, and crop regionalization. In 2001, Ministry of Agriculture and Animal Resources (MINAGRI) released the Rural Sector Support Program (RSSP), which aimed at converting marshlands into rice fields at various development sites across the country. The focus of this project was to monitor rice fields in Rwanda utilizing NASA Earth observations such as Landsat 5 Thematic Mapper and Landsat 8 Operational Land Imager. Modified Normalized Difference Water Index (MNDWI) was used to depict the progress of marshland to rice field conversion as it highlights the presence of irrigated rice fields from the surrounding area. Additionally, Decision Support System for Agrotechnology Transfer (DSSAT) was used to estimate rice yield at RSSP sites. Various simulations were run to find perfect conditions for cultivating the highest yield for a given farm. Furthermore, soil erosion susceptibility masks were created by combining factors derived from ASTER, MERRA, and ground truth data using Revised Universal Soil Loss Equation (RUSLE). The end results, maps, and tutorials were delivered to the partners and policy makers in Rwanda to help make informed decisions. It can be clearly seen that Earth observations can be successfully used to monitor agricultural and land management practices as a cost effective method that will enable farmers to improve crop yield production and food security.
Rewis, D.L.
1995-01-01
A ground-water-level monitoring program was implemented at Edwards Air Force Base, California, from January through December 1992 to monitor spatial and temporal changes in poten-tiometric surfaces that largely are affected by ground-water pumping. Potentiometric-surface maps are needed to determine the correlation between declining ground- water levels and the distribution of land subsidence. The monitoring program focused on areas of the base where pumping has occurred, especially near Rogers Lake, and involved three phases of data collection: (1) well canvassing and selection, (2) geodetic surveys, and (3) monthly ground-water-level measurements. Construction and historical water- level data were compiled for 118 wells and pi-ezometers on or near the base, and monthly ground-water-level measurements were made in 82 wells and piezometers on the base. The compiled water-level data were used in conjunction with previously collected geologic data to identify three types of no-flow boundaries in the aquifer system: structural boundaries, a principal-aquifer boundary, and ground-water divides. Heads were computed from ground-water-level measurements and land-surface altitudes and then were used to map seasonal potentiometric surfaces for the principal and deep aquifers underlying the base. Pumping has created a regional depression in the potentiometric surface of the deep aquifer in the South Track, South Base, and Branch Park well-field area. A 15-foot decline in the potentiometric surface from April to September 1992 and 20- to 30-foot drawdowns in the three production wells in the South Track well field caused locally unconfined conditions in the deep aquifer.
Impact of Land Model Calibration on Coupled Land-Atmosphere Prediction
NASA Technical Reports Server (NTRS)
Santanello, Joseph A., Jr.; Kumar, Sujay V.; Peters-Lidard, Christa D.; Harrison, Ken; Zhou, Shujia
2012-01-01
Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface heat and moisture budgets, as well as controlling feedbacks with clouds and precipitation that lead to the persistence of dry and wet regimes. Recent efforts to quantify the strength of L-A coupling in prediction models have produced diagnostics that integrate across both the land and PBL components of the system. In this study, we examine the impact of improved specification of land surface states, anomalies, and fluxes on coupled WRF forecasts during the summers of extreme dry and wet land surface conditions in the U.S. Southern Great Plains. The improved land initialization and surface flux parameterizations are obtained through calibration of the Noah land surface model using the new optimization and uncertainty estimation subsystem in NASA's Land Information System (LIS-OPT/UE). The impact of the calibration on the a) spinup of the land surface used as initial conditions, and b) the simulated heat and moisture states and fluxes of the coupled WRF simulations is then assessed. Changes in ambient weather and land-atmosphere coupling are evaluated along with measures of uncertainty propagation into the forecasts. In addition, the sensitivity of this approach to the period of calibration (dry, wet, average) is investigated. Results indicate that the offline calibration leads to systematic improvements in land-PBL fluxes and near-surface temperature and humidity, and in the process provide guidance on the questions of what, how, and when to calibrate land surface models for coupled model prediction.
Investigation of Hydrophobic Radomes for Microwave Landing System.
1982-11-01
horizontal heating wires on the inside surface, and 2) a slotted waveguide unit (C-band waveguide, about 2 feet in length) covered with a Teflon shrink tube ...AZ) Fiberglass flat 1.5ft x 13ft NE sandwich (EL) Teflon shrink 1 in x 2 ft SW tubing (Field Mon.) 7 (8) Hydrophobic Coating for Antenna Weather...SURFACE PREPARATION 13 24 Mar Conolite Primer: Vellox S-048 Finish: Microfine FSD, 7 coats, sprayed 14 24 Mar Conolite Teflon film, C-TAPE-36
The Urban Heat Island Impact in Consideration of Spatial Pattern of Urban Landscape and Structure
NASA Astrophysics Data System (ADS)
Kim, J.; Lee, D. K.; Jeong, W.; Sung, S.; Park, J.
2015-12-01
Preceding study has established a clear relationship between land surface temperature and area of land covers. However, only few studies have specifically examined the effects of spatial patterns of land covers and urban structure. To examine how much the local climate is affected by the spatial pattern in highly urbanized city, we investigated the correlation between land surface temperature and spatial patterns of land covers. In the analysis of correlation, we categorized urban structure to four different land uses: Apartment residential area, low rise residential area, industrial area and central business district. Through this study, we aims to examine the types of residential structure and land cover pattern for reducing urban heat island and sustainable development. Based on land surface temperature, we investigated the phenomenon of urban heat island through using the data of remote sensing. This study focused on Daegu in Korea. This city, one of the hottest city in Korea has basin form. We used high-resolution land cover data and land surface temperature by using Landsat8 satellite image to examine 100 randomly selected sample sites of 884.15km2 (1)In each land use, we quantified several landscape-levels and class-level landscape metrics for the sample study sites. (2)In addition, we measured the land surface temperature in 3 year hot summer seasons (July to September). Then, we investigated the pattern of land surface temperature for each land use through Ecognition package. (3)We deducted the Pearson correlation coefficients between land surface temperature and each landscape metrics. (4)We analyzed the variance among the four land uses. (5)Using linear regression, we determined land surface temperature model for each land use. (6)Through this analysis, we aims to examine the best pattern of land cover and artificial structure for reducing urban heat island effect in highly urbanized city. The results of linear regression showed that proportional land cover of grass, tree, water and impervious surfaces well explained the temperature in apartment residential areas. In contrast, the changes in the pattern of water, grass, tree and impervious surfaces were the best to determine the temperature in low rise residential area, central business district and industrial area.
Wieczorek, Michael; LaMotte, Andrew E.
2010-01-01
This tabular data set represents the estimated area of artifical drainage for the year 1992 and irrigation types for the year 1997 compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). The source data sets were derived from tabular National Resource Inventory (NRI) data sets created by the National Resources Conservation Service (NRCS, U.S. Department of Agriculture, 1995, 2000). Artificial drainage is defined as subsurface drains and ditches. Irrigation types are defined as gravity and pressure. Subsurface drains are described as conduits, such as corrugated plastic tubing, tile, or pipe, installed beneath the ground surface to collect and/or convey drainage. Surface drainage field ditches are described as graded ditches for collecting excess water. Gravity irrigation source is described as irrigation delivered to the farm and/or field by canals or pipelines open to the atmosphere; and water is distributed by the force of gravity down the field by: (1) A surface irrigation system (border, basin, furrow, corrugation, wild flooding, etc.) or (2) Sub-surface irrigation pipelines or ditches. Pressure irrigation source is described as irrigation delivered to the farm and/or field in pump or elevation-induced pressure pipelines, and water is distributed across the field by: (1) Sprinkle irrigation (center pivot, linear move, traveling gun, side roll, hand move, big gun, or fixed set sprinklers), or (2) Micro irrigation (drip emitters, continuous tube bubblers, micro spray or micro sprinklers). NRI data do not include Federal lands and are thus excluded from this dataset. The tabular data for drainage were spatially apportioned to the National Land Cover Dataset (NLCD, Kerie Hitt, U.S. Geological Survey, written commun., 2005) and the tabular data for irrigation were spatially apportioned to an enhanced version of the National Land Cover Dataset (NLCDe, Nakagaki and others, 2007). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).
Hydrologic connections between environmental and societal change at the Bonneville Salt Flats, Utah
NASA Astrophysics Data System (ADS)
Bowen, B. B.; Harman, C. J.; Kipnis, E. L.; Liu, T.; Bernau, J. A.; Horel, J.
2017-12-01
The Bonneville Salt Flats (BSF) is an ephemeral and valued salt pan in northwestern Utah where a century of land speed racing and potash mining have created a complex and intertwined social and hydrologic system. The character of BSF changes on daily, weekly, monthly, annual, and geologic time scales in response to fluctuations in water balance, solute flux, and groundwater flow which is impacted by both local meteorology and water management associated with potash mining. In addition, the texture of the salt surface is changed by land use including racing activities, which impacts water fluxes through the crust. Ongoing research is focused on characterizing physical changes in the BSF environment and attributing observed changes in the landscape to specific processes and drivers. Five years of field observations and sampling, analyses of satellite imagery dating back the 1980s, and geochemical analysis of surface brines have shown that spatiotemporal changes in surface water and fluctuations in the surface salt footprint are linked to both climate and land use. Climate data over the last 30 years are examined to identify annual patterns in surface water balance at BSF to identify annual and seasonal climate constraints on flooding, evaporation, and desiccation cycles. A new weather station installed in the Fall of 2016 in the middle of BSF allows for unprecedented analyses of halite surface dynamics. Spatiotemporally dispersed stable isotope analyses of BSF surface brine samples constrain brine sources and evolution. An understanding of the processes that change the surface composition and texture through time inform interpretation of subsurface saline deposits at BSF. The wide range of temporal and spatial scales of observation help to guide to best management practices of this iconic natural resource.
Consequences of land-cover misclassification in models of impervious surface
McMahon, G.
2007-01-01
Model estimates of impervious area as a function of landcover area may be biased and imprecise because of errors in the land-cover classification. This investigation of the effects of land-cover misclassification on impervious surface models that use National Land Cover Data (NLCD) evaluates the consequences of adjusting land-cover within a watershed to reflect uncertainty assessment information. Model validation results indicate that using error-matrix information to adjust land-cover values used in impervious surface models does not substantially improve impervious surface predictions. Validation results indicate that the resolution of the landcover data (Level I and Level II) is more important in predicting impervious surface accurately than whether the land-cover data have been adjusted using information in the error matrix. Level I NLCD, adjusted for land-cover misclassification, is preferable to the other land-cover options for use in models of impervious surface. This result is tied to the lower classification error rates for the Level I NLCD. ?? 2007 American Society for Photogrammetry and Remote Sensing.
2014-01-21
CAPE CANAVERAL, Fla. – Technicians and engineers perform safing procedures on the Project Morpheus prototype lander after it touched down in the autonomous landing and hazard avoidance technology, or ALHAT, hazard field. The lander successfully completed its fourth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 64-second test began at 1:15 p.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending about 305 feet, significantly increasing the ascent velocity from the last test. The lander flew forward, covering about 358 feet in 25 seconds before descending and landing within 15 inches of its target on a dedicated pad inside the ALHAT hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://www.nasa.gov/centers/johnson/exploration/morpheus. Photo credit: NASA/Kim Shiflett
Land cover heterogeneity and soil respiration in a west Greenland tundra landscape
NASA Astrophysics Data System (ADS)
Bradley-Cook, J. I.; Burzynski, A.; Hammond, C. R.; Virginia, R. A.
2011-12-01
Multiple direct and indirect pathways underlie the association between land cover classification, temperature and soil respiration. Temperature is a main control of the biological processes that constitute soil respiration, yet the effect of changing atmospheric temperatures on soil carbon flux is unresolved. This study examines associations amongst land cover, soil carbon characteristics, soil respiration, and temperature in an Arctic tundra landscape in western Greenland. We used a 1.34 meter resolution multi-spectral WorldView2 satellite image to conduct an unsupervised multi-staged ISODATA classification to characterize land cover heterogeneity. The four band image was taken on July 10th, 2010, and captures an 18 km by 15 km area in the vicinity of Kangerlussuaq. The four major terrestrial land cover classes identified were: shrub-dominated, graminoid-dominated, mixed vegetation, and bare soil. The bare soil class was comprised of patches where surface soil has been deflated by wind and ridge-top fellfield. We hypothesize that soil respiration and soil carbon storage are associated with land cover classification and temperature. We set up a hierarchical field sampling design to directly observe spatial variation between and within land cover classes along a 20 km temperature gradient extending west from Russell Glacier on the margin of the Greenland Ice Sheet. We used the land cover classification map and ground verification to select nine sites, each containing patches of the four land cover classes. Within each patch we collected soil samples from a 50 cm pit, quantified vegetation, measured active layer depth and determined landscape characteristics. From a subset of field sites we collected additional 10 cm surface soil samples to estimate soil heterogeneity within patches and measured soil respiration using a LiCor 8100 Infrared Gas Analyzer. Soil respiration rates varied with land cover classes, with values ranging from 0.2 mg C/m^2/hr in the bare soil class to over 5 mg C/m^2/hr in the graminoid-dominated class. These findings suggest that shifts in land cover vegetation types, especially soil and vegetation loss (e.g. from wind deflation), can alter landscape soil respiration. We relate soil respiration measurements to soil, vegetation, and permafrost characteristics to understand how ecosystem properties and processes vary at the landscape scale. A long-term goal of this research is to develop a spatially explicit model of soil organic matter, soil respiration, and temperature sensitivity of soil carbon dynamics for a western Greenland permafrost tundra ecosystems.
Prediction of Estrogen Runoff and Transport Driven by Rainfalls from Swine Spray Fields
NASA Astrophysics Data System (ADS)
Lee, B.; Reckhow, K. H.; Kullman, S. W.
2010-12-01
Animal waste-borne steroidal hormones, which are referred to as natural steroidal estrogens, are recognized pollutants to surface water systems. Steroidal estrogens exhibit strong potency, even at very low concentrations, as endocrine disrupting chemicals on aquatic organisms. In North Carolina, the swine concentrated animal feeding operations (CAFOs) have been a major source for the release of estrogens to watersheds. Release is a direct result of the land application of the generated waste as an organic fertilizer. However, data regarding the estrogen loss and transport through the surface runoff and soil erosion to the water bodies after the spray-fields application has been up till now very limited. We have developed a decision support tool that can help predict and ultimately manage the potential mobilization and transport of estrogens from CAFOs, through the processes of surface runoff transport and sediment loss, into adjacent water bodies. Our decision support tool was built using a dynamic Bayesian Network (DBN) framework. The developed DBN model integrates the processes of a sediment loss and a surface runoff by using the modified universal soil loss equation (MUSLE) and the SCS-CN curve runoff models. Estrogen mobility is assessed as a function of rainfall intensity and land use management with consideration to the temporal distribution of both. The DBN is used to model the estrogen concentration in the runoff process, to determine the degree of off-site movement of estrogens, and to verify the potential environmental significance of the estrogen inputs into the stream. We believe that our modeling framework is particularly useful for use in field situations where estrogen runoff data are not available or are scarce. The DBN model also provides a means to handle the uncertainties of mathematical sediment and runoff models as a dynamic probability model.
Viking Landers and remote sensing
NASA Technical Reports Server (NTRS)
Moore, H. J.; Jakosky, B. M.; Christensen, P. R.
1987-01-01
Thermal and radar remote sensing signatures of the materials in the lander sample fields can be crudely estimated from evaluations of their physical-mechanical properties, laboratory data on thermal conductivities and dielectric constants, and theory. The estimated thermal inertias and dielectric constants of some of the materials in the sample field are close to modal values estimated from orbital and earth-based observations. This suggests that the mechanical properties of the surface materials of much of Mars will not be significantly different that those of the landing sites.
Influence of Roughness-Induced Slip on Colloid Transport: Experimental and Modelling Insights
NASA Astrophysics Data System (ADS)
Rasmuson, J. A.; Johnson, W. P.
2017-12-01
A limitation of classic colloid filtration theory is that it applies only to smooth surfaces, yet most natural surfaces present some degree of nano- to micro-scale roughness. A large volume of research has been dedicated to understanding the effects of roughness on particle attachment at the nano-scale since these interactions dictate field scale transport behavior. It has been previously demonstrated that roughness imposes a finite slip vector at the surface that causes particles to experience higher near-surface velocities than would be expected over a smooth surface. Slip near a rough surface can affect two primary mechanisms of particle attenuation: 1) interception of the surface (finding a landing spot) and 2) arrest on the surface (sticking the landing). However, a clear designation on how slip affects particle transport near rough surfaces is missing. The goal of this study was to provide a guide for the height of the slip layer and contact surface in reference to the mean-plane for rough surfaces. Direct observation was used to measure near-surface velocities of particles translating near surfaces of varying roughness spanning three orders of magnitude. The influence of roughness on particle transport was investigated using computational fluid dynamics (CFD) modeling with rough surfaces measured with atomic force microscopy (AFM). The CFD and experimental results were used to calibrate a Lagrangian particle transport model that utilizes simple modifications to the flow field for a smooth surface using statistically based roughness parameters. Advantages of the Lagrangian model are significantly decreased computation times and applicability to a wide range of natural surfaces without explicitly simulating individual asperities. The results suggest that the no-slip boundary should be placed at the bottom of the maximum asperity valleys, and that the contact surface should be placed at the root mean square (RMS) roughness above the mean plane. Collector surfaces with the greatest RMS roughness had the highest sensitivity to the placement of the contact surface. These findings highlight the need for accurate and representative AFM measurements and have important implications for future transport models.
NASA Technical Reports Server (NTRS)
Reining, P. (Principal Investigator)
1974-01-01
The author has identified the following significant results. Repetitively derived multispectral band imagery from ERTS-1 is now available for many parts of the earth's land surface and represents major new data sources for anthropological work in habitat, land use, and settlement patterns. A completed first step test of ERTS-1 data is available in carrying capacity estimates for Mossi, Hausa, and Sonrai sites derived from: (1) field work; (2) aerial photography; and (3) ERTS-1. Data can test more than one carrying capacity formula.
1997-07-05
Portions of Mars Pathfinder's deflated airbags (seen in the foreground), a large rock in mid-field, and a hill in the background were taken by the Imager for Mars Pathfinder (IMP) aboard Mars Pathfinder during the spacecraft's first day on the Red Planet. Pathfinder successfully landed on Mars at 10:07 a.m. PDT earlier today. The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per "eye." It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. http://photojournal.jpl.nasa.gov/catalog/PIA00615
Mosaic of Apollo 16 Descartes landing site taken from TV transmission
NASA Technical Reports Server (NTRS)
1972-01-01
A 360 degree field of view of the Apollo 16 Descartes landing site area composed of individual scenes taken from a color transmission made by the color RCA TV camera mounted on the Lunar Roving Vehicle. This panorama was made while the LRV was parked at the rim of Flag Crater (Station 1) during the first Apollo 16 lunar surface extravehicular activity (EVA-1) by Astronauts John W. Young and Charles M. Duke Jr. The overlay identifies the directions and the key lunar terrain features. The camera panned across the rear portion of the LRV in its 360 degree sweep.
NASA Technical Reports Server (NTRS)
Johnson, Howell K.; Green, Robert O.
1995-01-01
This paper serves as a brief overview of the AVIRIS instrument (Airborne Visible/Infrared Imaging Spectrometer). The AVIRIS sensor collects data that will be used for quantitative characterization of the Earth's surface and atmosphere from geometrically coherent spectroradiometric measurements. This data can be applied to studies in the fields of oceanography, environmental science, snow hydrology, geology, volcanology, soil and land management, atmospheric and aerosol studies, agriculture, and limnology. Applications under development include the assessment and monitoring of environmental hazards such as toxic waste, oil spills, and land/air/water pollution. Mission planning and flight operations are discussed, and recommendations are given regarding the deployment of ground truth experiments.
NASA Technical Reports Server (NTRS)
Peters-Lidar, Christa D.; Tian, Yudong; Kenneth, Tian; Harrison, Kenneth; Kumar, Sujay
2011-01-01
Land surface modeling and data assimilation can provide dynamic land surface state variables necessary to support physical precipitation retrieval algorithms over land. It is well-known that surface emission, particularly over the range of frequencies to be included in the Global Precipitation Measurement Mission (GPM), is sensitive to land surface states, including soil properties, vegetation type and greenness, soil moisture, surface temperature, and snow cover, density, and grain size. In order to investigate the robustness of both the land surface model states and the microwave emissivity and forward radiative transfer models, we have undertaken a multi-site investigation as part of the NASA Precipitation Measurement Missions (PMM) Land Surface Characterization Working Group. Specifically, we will demonstrate the performance of the Land Information System (LIS; http://lis.gsfc.nasa.gov; Peters-Lidard et aI., 2007; Kumar et al., 2006) coupled to the Joint Center for Satellite Data Assimilation (JCSDA's) Community Radiative Transfer Model (CRTM; Weng, 2007; van Deist, 2009). The land surface is characterized by complex physical/chemical constituents and creates temporally and spatially heterogeneous surface properties in response to microwave radiation scattering. The uncertainties in surface microwave emission (both surface radiative temperature and emissivity) and very low polarization ratio are linked to difficulties in rainfall detection using low-frequency passive microwave sensors (e.g.,Kummerow et al. 2001). Therefore, addressing these issues is of utmost importance for the GPM mission. There are many approaches to parameterizing land surface emission and radiative transfer, some of which have been customized for snow (e.g., the Helsinki University of Technology or HUT radiative transfer model;) and soil moisture (e.g., the Land Surface Microwave Emission Model or LSMEM).
Evaluation of GIS Technology in Assessing and Modeling Land Management Practices
NASA Technical Reports Server (NTRS)
Archer, F.; Coleman, T. L.; Manu, A.; Tadesse, W.; Liu, G.
1997-01-01
There is an increasing concern of land owners to protect and maintain healthy and sustainable agroecosystems through the implementation of best management practices (BMP). The objectives of this study were: (1) To develop and evaluate the use of a Geographic Information System (GIS) technology for enhancing field-scale management practices; (2) evaluate the use of 2-dimensional displays of the landscape and (3) define spatial classes of variables from interpretation of geostatistical parameters. Soil samples were collected to a depth of 2 m at 15 cm increments. Existing data from topographic, land use, and soil survey maps of the Winfred Thomas Agricultural Research Station were converted to digital format. Additional soils data which included texture, pH, and organic matter were also generated. The digitized parameters were used to create a multilayered field-scale GIS. Two dimensional (2-D) displays of the parameters were generated using the ARC/INFO software. The spatial distribution of the parameters evaluated in both fields were similar which could be attributed to the similarity in vegetation and surface elevation. The ratio of the nugget to total semivariance, expressed as a percentage, was used to assess the degree of spatial variability. The results indicated that most of the parameters were moderate spatially dependent Biophysical constraint maps were generated from the database layers, and used in multiple combination to visualize results of the BMP. Understanding the spatial relationships of physical and chemical parameters that exists within a field should enable land managers to more effectively implement BMP to ensure a safe and sustainable environment.
Jones, J.W.
2000-01-01
The US Geological Survey is building models of the Florida Everglades to be used in managing south Florida surface water flows for habitat restoration and maintenance. Because of the low gradients in the Everglades, vegetation structural characteristics are very important and greatly influence surface water flow and distribution. Vegetation density is being evaluated as an index of surface resistance to flow. Digital multispectral videography (DMSV) has been captured over several sites just before field collection of vegetation data. Linear regression has been used to establish a relationship between normalized difference vegetation index (NDVI) values computed from the DMSV and field-collected biomass and density estimates. Spatial analysis applied to the DMSV data indicates that thematic mapper (TM) resolution is at the limit required to capture land surface heterogeneity. The TM data collected close to the time of the DMSV will be used to derive a regional sawgrass density map.
Jones, J.W.
2001-01-01
The US Geological Survey is building models of the Florida Everglades to be used in managing south Florida surface water flows for habitat restoration and maintenance. Because of the low gradients in the Everglades, vegetation structural characteristics are very important and greatly influence surface water flow and distribution. Vegetation density is being evaluated as an index of surface resistance to flow. Digital multispectral videography (DMSV) has been captured over several sites just before field collection of vegetation data. Linear regression has been used to establish a relationship between normalized difference vegetation index (NDVI) values computed from the DMSV and field-collected biomass and density estimates. Spatial analysis applied to the DMSV data indicates that thematic mapper (TM) resolution is at the limit required to capture land surface heterogeneity. The TM data collected close to the time of the DMSV will be used to derive a regional sawgrass density map.
Southern Meridiani Planum - A candidate landing site for the first crewed mission to Mars
NASA Astrophysics Data System (ADS)
Clarke, J. D. A.; Willson, D.; Smith, H.; Hobbs, S. W.; Jones, E.
2017-04-01
Astronauts working on the surface of Mars have the capability to explore efficiently, rapidly, and flexibly, allowing them to perform a wide range of field investigations. NASA has begun an open international process to identify and evaluate candidate locations where crews could land, live and work on the martian surface, beginning with the First Landing Site/Exploration Zone Workshop for Human Missions to the Surface of Mars in October 2015. Forty seven sites were proposed, including several at or near the Meridiani area, the subject of this paper. We consider the Meridiani area an excellent candidate for the first missions to Mars. It is accessible, safe, contains potential water resources in the form of poly-hydrated magnesium sulphates, has diverse science features with high likelihood of meeting all science goals, has other potential resources and potential for further longer-ranged exploration. The presence of hardware from previous missions will be of benefit to studies of materials to martian conditions, assessing the effectiveness of historic planetary protection strategies, and engaging public interest. Lastly, parts of the Meridiani region have been well studied from the surface by the Opportunity mission, providing ground truth for orbital data. As one of the best documented regions of Mars this will allow a "Go where you know" approach for the first crewed missions, especially with regard to safety, trafficability, and water resource potential.
Sensitivity of Land Surface Parameters on Thunderstorm Simulation through HRLDAS-WRF Coupling Mode
NASA Astrophysics Data System (ADS)
Kumar, Dinesh; Kumar, Krishan; Mohanty, U. C.; Kisore Osuri, Krishna
2016-07-01
Land surface characteristics play an important role in large scale, regional and mesoscale atmospheric process. Representation of land surface characteristics can be improved through coupling of mesoscale atmospheric models with land surface models. Mesoscale atmospheric models depend on Land Surface Models (LSM) to provide land surface variables such as fluxes of heat, moisture, and momentum for lower boundary layer evolution. Studies have shown that land surface properties such as soil moisture, soil temperature, soil roughness, vegetation cover, have considerable effect on lower boundary layer. Although, the necessity to initialize soil moisture accurately in NWP models is widely acknowledged, monitoring soil moisture at regional and global scale is a very tough task due to high spatial and temporal variability. As a result, the available observation network is unable to provide the required spatial and temporal data for the most part of the globe. Therefore, model for land surface initializations rely on updated land surface properties from LSM. The solution for NWP land-state initialization can be found by combining data assimilation techniques, satellite-derived soil data, and land surface models. Further, it requires an intermediate step to use observed rainfall, satellite derived surface insolation, and meteorological analyses to run an uncoupled (offline) integration of LSM, so that the evolution of modeled soil moisture can be forced by observed forcing conditions. Therefore, for accurate land-state initialization, high resolution land data assimilation system (HRLDAS) is used to provide the essential land surface parameters. Offline-coupling of HRLDAS-WRF has shown much improved results over Delhi, India for four thunder storm events. The evolution of land surface variables particularly soil moisture, soil temperature and surface fluxes have provided more realistic condition. Results have shown that most of domain part became wetter and warmer after assimilation of soil moisture and soil temperature at the initial condition which helped to improve the exchange fluxes at lower atmospheric level. Mixing ratio were increased along with elevated theta-e at lower level giving a signature of improvement in LDAS experiment leading to a suitable condition for convection. In the analysis, moisture convergence, mixing ratio and vertical velocities have improved significantly in terms of intensity and time lag. Surface variables like soil moisture, soil temperature, sensible heat flux and latent heat flux have progressed in a possible realistic pattern. Above discussion suggests that assimilation of soil moisture and soil temperature improves the overall simulations significantly.
Impacts of land cover transitions on surface temperature in China based on satellite observations
NASA Astrophysics Data System (ADS)
Zhang, Yuzhen; Liang, Shunlin
2018-02-01
China has experienced intense land use and land cover changes during the past several decades, which have exerted significant influences on climate change. Previous studies exploring related climatic effects have focused mainly on one or two specific land use changes, or have considered all land use and land cover change types together without distinguishing their individual impacts, and few have examined the physical processes of the mechanism through which land use changes affect surface temperature. However, in this study, we considered satellite-derived data of multiple land cover changes and transitions in China. The objective was to obtain observational evidence of the climatic effects of land cover transitions in China by exploring how they affect surface temperature and to what degree they influence it through the modification of biophysical processes, with an emphasis on changes in surface albedo and evapotranspiration (ET). To achieve this goal, we quantified the changes in albedo, ET, and surface temperature in the transition areas, examined their correlations with temperature change, and calculated the contributions of different land use transitions to surface temperature change via changes in albedo and ET. Results suggested that land cover transitions from cropland to urban land increased land surface temperature (LST) during both daytime and nighttime by 0.18 and 0.01 K, respectively. Conversely, the transition of forest to cropland tended to decrease surface temperature by 0.53 K during the day and by 0.07 K at night, mainly through changes in surface albedo. Decreases in both daytime and nighttime LST were observed over regions of grassland to forest transition, corresponding to average values of 0.44 and 0.20 K, respectively, predominantly controlled by changes in ET. These results highlight the necessity to consider the individual climatic effects of different land cover transitions or conversions in climate research studies. This short-term analysis of land cover transitions in China means our estimates should represent local temperature effects. Changes in ET and albedo explained <60% of the variation in LST change caused by land cover transitions; thus, additional factors that affect surface climate need consideration in future studies.
NASA Astrophysics Data System (ADS)
Illangasekare, T. H.; Smits, K. M.; Trautz, A.; Rice, A. K.; Cihan, A.; Davarzani, H.
2013-12-01
SSoil moisture processes in the subsurface/near-land-surface, play a crucial role in the hydrologic cycle and global water budget. This zone is subject to both natural and human induced disturbances, resulting in continually changing soil structure and hydraulic, thermal, and mechanical properties. Understanding of the dynamics of soil moisture distribution in this zone is of interest in various applications in hydrology such as land-atmospheric interaction, soil evaporation and evapotranspiration, as well as emerging problems on assessing the risk of leakage of sequestrated CO2 from deep geologic formations to the shallow subsurface, and potential leakage of methane to the atmosphere in shale gas development that contributes to global warming. Shallow subsurface soil moisture is highly influenced by diurnal temperature variations, evaporation/condensation, precipitation and liquid water and water vapor flow, all of which are strongly coupled. Modeling studies, have shown that soil moisture in this zone is highly sensitive to the heat and mass flux boundary conditions at the land surface. Hence, approximation of these boundary conditions without properly incorporating complex feedback between the land and the atmospheric boundary layer are expected to result in significant errors. Even though considerable knowledge exists on how soil moisture changes in response to the flux and energy boundary conditions, emerging problems involving land atmospheric interactions require the quantification of soil moisture variability at higher spatial and temporal resolutions than what is needed in traditional applications in soil physics and vadose zone hydrology. These factors lead to many modeling challenges, primarily of which is the issue of up-scaling. It is our contention that knowledge that will contribute to both improving our understanding of the fundamental processes and practical problem solutions cannot be obtained using only field data. Basic to this limitation is the inability to make field measurements at very fine scales at high temporal resolutions. Also, as the natural boundary conditions at the land/atmospheric interface are not controllable in the field, even in pilot scale studies, the developed theories and models cannot be validated for a diversity of conditions that could be expected. As an alternative, we propose an innovative testing approach that couples a low velocity boundary layer climate wind tunnel to intermediate scale porous media tanks. Intermediate scale testing using soil tanks packed to represent different heterogeneous test configurations provides an attractive and cost effective alternative to investigate a class of problems involving the shallow unsaturated zone. In this talk, we will present examples of studies we have conducted in a hierarchy of test systems, including the intermediate scale. The advantages and limitations of testing at this scale are discussed using these examples. The features and capabilities of newly developed test systems are presented with the goal of exploring opportunities to use them to study some of the challenging multi-scale problems in the near surface unsaturated zone.
NASA Astrophysics Data System (ADS)
Jiménez-Esteve, B.; Udina, M.; Soler, M. R.; Pepin, N.; Miró, J. R.
2018-04-01
Different types of land use (LU) have different physical properties which can change local energy balance and hence vertical fluxes of moisture, heat and momentum. This in turn leads to changes in near-surface temperature and moisture fields. Simulating atmospheric flow over complex terrain requires accurate local-scale energy balance and therefore model grid spacing must be sufficient to represent both topography and land-use. In this study we use both the Corine Land Cover (CLC) and United States Geological Survey (USGS) land use databases for use with the Weather Research and Forecasting (WRF) model and evaluate the importance of both land-use classification and horizontal resolution in contributing to successful modelling of surface temperatures and humidities observed from a network of 39 sensors over a 9 day period in summer 2013. We examine case studies of the effects of thermal inertia and soil moisture availability at individual locations. The scale at which the LU classification is observed influences the success of the model in reproducing observed patterns of temperature and moisture. Statistical validation of model output demonstrates model sensitivity to both the choice of LU database used and the horizontal resolution. In general, results show that on average, by a) using CLC instead of USGS and/or b) increasing horizontal resolution, model performance is improved. We also show that the sensitivity to these changes in the model performance shows a daily cycle.
NASA Technical Reports Server (NTRS)
Cook, B. I.; Seager, R.; Miller, R. L.
2011-01-01
During the Medieval Climate Anomaly, North America experienced severe droughts and widespread mobilization of dune fields that persisted for decades. We use an atmosphere general circulation model, forced by a tropical Pacific sea surface temperature reconstruction and changes in the land surface consistent with estimates of dune mobilization (conceptualized as partial devegetation), to investigate whether the devegetation could have exacerbated the medieval droughts. Presence of devegetated dunes in the model significantly increases surface temperatures, but has little impact on precipitation or drought severity, as defined by either the Palmer Drought Severity Index or the ratio of precipitation to potential evapotranspiration. Results are similar to recent studies of the 1930s Dust Bowl drought, suggesting bare soil associated with the dunes, in and of itself, is not sufficient to amplify droughts over North America.
An Evaluation of ALOS Data in Disaster Applications
NASA Astrophysics Data System (ADS)
Igarashi, Tamotsu; Igarashi, Tamotsu; Furuta, Ryoich; Ono, Makoto
ALOS is the advanced land observing satellite, providing image data from onboard sensors; PRISM, AVNIR-2 and PALSAR. PRISM is the sensor of panchromatic stereo, high resolution three-line-scanner to characterize the earth surface. The accuracy of position in image and height of Digital Surface Model (DSM) are high, therefore the geographic information extraction is improved in the field of disaster applications with providing images of disaster area. Especially pan-sharpened 3D image composed with PRISM and the four-band visible near-infrared radiometer AVNIR-2 data is expected to provide information to understand the geographic and topographic feature. PALSAR is the advanced multi-functional synthetic aperture radar (SAR) operated in L-band, appropriate for the use of land surface feature characterization. PALSAR has many improvements from JERS-1/SAR, such as high sensitivity, having high resolution, polarimetric and scan SAR observation modes. PALSAR is also applicable for SAR interferometry processing. This paper describes the evaluation of ALOS data characteristic from the view point of disaster applications, through some exercise applications.
Mössbauer spectroscopy on Mars: goethite in the Columbia Hills at Gusev crater
NASA Astrophysics Data System (ADS)
Klingelhöfer, G.; Degrave, E.; Morris, R. V.; van Alboom, A.; de Resende, V. G.; de Souza, P. A.; Rodionov, D.; Schröder, C.; Ming, D. W.; Yen, A.
2005-11-01
In January 2004 the USA space agency NASA landed two rovers on the surface of Mars, both carrying the Mainz Mössbauer spectrometer MIMOS II. The instrument on the Mars-Exploration-Rover (MER) Spirit analyzed soils and rocks on the plains and in the Columbia Hills of Gusev crater landing site on Mars. The surface material in the plains have an olivine basaltic signature [1, 5] suggesting physical rather than chemical weathering processes present in the plains. The Mössbauer signature for the Columbia Hills surface material is very different ranging from nearly unaltered material to highly altered material. Some of the rocks, in particular a rock named Clovis, contain a significant amount of the Fe oxyhydroxide goethite, α-FeOOH, which is mineralogical evidence for aqueous processes because it is formed only under aqueous conditions. In this paper we describe the analysis of these data using hyperfine field distributions (HFD) and discuss the results in comparison to terrestrial analogues.
USDA-ARS?s Scientific Manuscript database
High spatial heterogeneity in ground cover, large amounts of exposed bare soil, and modest cover from shrubs and grasses in arid and semi-arid ecosystems challenge the integration of field observations of phenology and remotely sensed data to monitor changes in land surface phenology. This research ...
FIELD SCALE EVALUATION OF TREATMENT OF TCE IN A BIOWALL AT THE OU-1 SITE
A passive reactive barrier (Biowall) was installed at the OU-1 site at Altus Air Force Base, Oklahoma to treat TCE contamination in ground water from a landfill. Depth to ground water varies from 1.8 to 2.4 meters below land surface. To intercept and treat the plume of contamin...
COMPACT: The role of soil management in mitigating catchment flood risk
NASA Astrophysics Data System (ADS)
Pattison, Ian; Coates, Victoria; Frost, Matthew; Demirci, Emrah
2017-04-01
This paper reports a new NERC funded research project which addresses the impact of agricultural soil compaction on surface runoff and catchment scale flood risk. The intensification of agriculture, through increasing the number of animals in pasture, and the use of larger, heavier machinery for arable farming, over the past 50 years or so is hypothesised to have had an impact on the severity and frequency of flooding. These land management practices cause soil compaction, which reduces the rate of rainfall infiltration and the volume of water that can be stored within the sub-surface. This results in more rainfall being partitioned into the faster surface runoff pathway into rivers and potentially causing flooding downstream. However, the level of soil compaction is highly heterogeneous over space and time. This is because different animals i.e. cattle, sheep and horses, exert different loads on the soil and are kept at different densities. Furthermore, farm animals are known to exhibit behaviour whereby certain parts of the field are moved over more frequently than others. The same is the case in arable farming practices, whereby ploughing forms tramlines or wheelings, which are more compacted. Different forms of management practice ranging from zero-tillage to conventional cultivation exert different pressures on the soil at different times of year. However, very little is known about this variability of soil compaction levels at the sub-field level and land under different management practices. This research aims to quantify this sub-field variation in compaction severity and depths through using novel Ground Penetrating Radar (GPR) and Animal tracking GPS technology. Combining these with more conventional soil property tests, including bulk density, saturated hydraulic conductivity and using a penetrometer will allow relationships with frequency of load to be developed over different spatial and temporal scales. Furthermore, X-Ray CT scanning will reveal the fine scale impacts of compaction on soil structure. This data will form the input to a physically based, reduced complexity, spatially distributed hydrological model to test feasible "what if?" scenarios. This will upscale local changes in land management and soil characteristics to catchment scale flooding. Results from research focussing on a priori compacted areas, such as feeding areas, field gates, shelter zones and tractor wheelings show that these are statistically different to areas assumed to be less compacted in the open field.
Introduction to special section on impacts of land use change on water resources
Stonestrom, David A.; Scanlon, Bridget R.; Zhang, Lu
2009-01-01
Changes in land use have potentially large impacts on water resources, yet quantifying these impacts remains among the more challenging problems in hydrology. Water, food, energy, and climate are linked through complex webs of direct and indirect effects and feedbacks. Land use is undergoing major changes due not only to pressures for more efficient food, feed, and fiber production to support growing populations but also due to policy shifts that are creating markets for biofuel and agricultural carbon sequestration. Hydrologic systems embody flows of water, solutes, sediments, and energy that vary even in the absence of human activity. Understanding land use impacts thus necessitates integrated scientific approaches. Field measurements, remote sensing, and modeling studies are shedding new light on the modes and mechanisms by which land use changes impact water resources. Such studies can help deconflate the interconnected influences of human actions and natural variations on the quantity and quality of soil water, surface water, and groundwater, past, present, and future.
BOREAS AFM-12 1-km AVHRR Seasonal Land Cover Classification
NASA Technical Reports Server (NTRS)
Steyaert, Lou; Hall, Forrest G.; Newcomer, Jeffrey A. (Editor); Knapp, David E. (Editor); Loveland, Thomas R.; Smith, David E. (Technical Monitor)
2000-01-01
The Boreal Ecosystem-Atmosphere Study (BOREAS) Airborne Fluxes and Meteorology (AFM)-12 team's efforts focused on regional scale Surface Vegetation and Atmosphere (SVAT) modeling to improve parameterization of the heterogeneous BOREAS landscape for use in larger scale Global Circulation Models (GCMs). This regional land cover data set was developed as part of a multitemporal one-kilometer Advanced Very High Resolution Radiometer (AVHRR) land cover analysis approach that was used as the basis for regional land cover mapping, fire disturbance-regeneration, and multiresolution land cover scaling studies in the boreal forest ecosystem of central Canada. This land cover classification was derived by using regional field observations from ground and low-level aircraft transits to analyze spectral-temporal clusters that were derived from an unsupervised cluster analysis of monthly Normalized Difference Vegetation Index (NDVI) image composites (April-September 1992). This regional data set was developed for use by BOREAS investigators, especially those involved in simulation modeling, remote sensing algorithm development, and aircraft flux studies. Based on regional field data verification, this multitemporal one-kilometer AVHRR land cover mapping approach was effective in characterizing the biome-level land cover structure, embedded spatially heterogeneous landscape patterns, and other types of key land cover information of interest to BOREAS modelers.The land cover mosaics in this classification include: (1) wet conifer mosaic (low, medium, and high tree stand density), (2) mixed coniferous-deciduous forest (80% coniferous, codominant, and 80% deciduous), (3) recent visible bum, vegetation regeneration, or rock outcrops-bare ground-sparsely vegetated slow regeneration bum (four classes), (4) open water and grassland marshes, and (5) general agricultural land use/ grasslands (three classes). This land cover mapping approach did not detect small subpixel-scale landscape features such as fens, bogs, and small water bodies. Field observations and comparisons with Landsat Thematic Mapper (TM) suggest a minimum effective resolution of these land cover classes in the range of three to four kilometers, in part, because of the daily to monthly compositing process. In general, potential accuracy limitations are mitigated by the use of conservative parameterization rules such as aggregation of predominant land cover classes within minimum horizontal grid cell sizes of ten kilometers. The AFM-12 one-kilometer AVHRR seasonal land cover classification data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).
New Versions of MISR Aerosol and Land Surface Products Available
Atmospheric Science Data Center
2018-02-14
New Versions of MISR Aerosol and Land Surface Products Available Monday, February 12, ... the release of new versions of the MISR Level 2 (L2) Aerosol Product, the MISR L2 Land Surface Product, and the Level 3 (L3) Component Global Aerosol and Land Surface Products. The new MISR L2 Aerosol Product ...
NASA Astrophysics Data System (ADS)
Shao, Yaping; Liu, Shaofeng; Schween, Jan H.; Crewell, Susanne
2013-08-01
A model is developed for the large-eddy simulation (LES) of heterogeneous atmosphere and land-surface processes. This couples a LES model with a land-surface scheme. New developments are made to the land-surface scheme to ensure the adequate representation of atmosphere-land-surface transfers on the large-eddy scale. These include, (1) a multi-layer canopy scheme; (2) a method for flux estimates consistent with the large-eddy subgrid closure; and (3) an appropriate soil-layer configuration. The model is then applied to a heterogeneous region with 60-m horizontal resolution and the results are compared with ground-based and airborne measurements. The simulated sensible and latent heat fluxes are found to agree well with the eddy-correlation measurements. Good agreement is also found in the modelled and observed net radiation, ground heat flux, soil temperature and moisture. Based on the model results, we study the patterns of the sensible and latent heat fluxes, how such patterns come into existence, and how large eddies propagate and destroy land-surface signals in the atmosphere. Near the surface, the flux and land-use patterns are found to be closely correlated. In the lower boundary layer, small eddies bearing land-surface signals organize and develop into larger eddies, which carry the signals to considerably higher levels. As a result, the instantaneous flux patterns appear to be unrelated to the land-use patterns, but on average, the correlation between them is significant and persistent up to about 650 m. For a given land-surface type, the scatter of the fluxes amounts to several hundred W { m }^{-2}, due to (1) large-eddy randomness; (2) rapid large-eddy and surface feedback; and (3) local advection related to surface heterogeneity.
Influence of climate and land use changes on recent trend of soil erosion within the Russian Plain
NASA Astrophysics Data System (ADS)
Golosov, Valentin; Yermolaev, Oleg; Rysin, Ivan; Litvin, Leonid; Kiryukhina, Zoya; Safina, Guzel
2016-04-01
The Russian Plain is one of the largest plains with an area of 460 × 106 ha. Soil erosion during snow-melting and rainstorms occurs mostly on arable lands at the Russian Plain. The relative contribution of different types of soil erosion changes from the central part of the Russian Plain to the south. Sheet and rill soil erosion during snow-melting and rainfall are practically equal in the forest zone, while rainfall erosion prevails in the forest-steppe zone and the northern part of the steppe zone. Mostly rainfall erosion is observed in the southern part of the steppe zone. Mean annual soil losses from cultivated lands change in the range from 1 to 3 t ha-1 within lowlands to 6 to 8 t ha-1 at uplands with the maximum (10 t ha-1) observed near the Caucasus Mountains in the Stavropolskiy Krai. The intensity of gully erosion is relatively low during the last two decades. The collapse of the Soviet Union in 1991 caused a serious crisis in the agriculture because of financial problems and structural reorganization. As a result, the area of arable lands decreased in the southern half of the Russian Plain in 1991 - 2003. To a greater extent it was observed in the south of the forest zone because of the low productivity of its soils compared with chernozem. More than one third of the arable lands were abandoned in the dry steppe - semi-desert zones because these lands were irrigated during the Soviet period. The reduction of the arable land occurred in the forest-steppe and steppe zones mostly because of funding limitations during the 1990s. Recently the area of arable lands in the steppe zone was practically restored to its pre-1991 size. Simultaneously the last 25 years are characterized by unusual warm winters - in particular, in the southern half of the Russian Plain because of the global warming. As a result, the coefficient of surface snow-melting runoff considerably decreased for both cultivated fields and compacted fields after harvesting. Accordingly, spring flood levels decreased considerably - in particular, in small rivers. This is confirmed by a serious decrease of floodplain sedimentation rates since 1986 compared with the period from 1964 to 1986. As a result of both positive trend of extreme rainfall and negative trend of surface snow melting runoff, the proportion of sediments eroded from cultivated slopes and delivered by surface runoff to river channels decreased considerably during the last few decades in the southern part of the Russian Plain. Complex assessment of different erosion factors changes is undertaken for the different landscape zones of the Russian Plain. Given analysis allows evaluating of recent trend in erosion rates from cultivated lands. The other indicators of sediment redistribution dynamic (gully head retreat rate, floodplain sedimentation) are also used for assessment of soil erosion rate dynamic under land use and climate changes during last 25-30 years.
Gao, Yongnian; Gao, Junfeng; Chen, Jiongfeng
2011-01-01
The study presented in this paper attempts to evaluate the spatial pattern of soil available phosphorus, as well as the relation between soil available phosphorus and environment factors including elevation, slope, precipitation, percentage of cultivated land, percentage of forest land, percentage of construction land and NDVI using statistical methods and GIS spatial analysis techniques. The results showed that the Spline Tension method performed the best in the prediction of soil available phosphorus in the Chaohu Lake watershed. The spatial variation of surface soil available phosphorus was high in Chaohu Lake watershed and the upstream regions around Chaohu Lake, including the west of Chaohu lake (e.g., southwest of Feixi county, east of Shucheng county and north of Lujiang county) and to the north of Chaohu Lake (e.g., south of Hefei city, south of Feidong county, southwest of Juchao district), had the highest soil available phosphorus content. The mean and standard deviation of soil available phosphorus content gradually decreased as the elevation or slope increased. The cultivated land comprised 60.11% of the watershed and of that land 65.63% belonged to the medium to very high SAP level classes, and it played a major role in SAP availability within the watershed and a potential source of phosphorus to Chaohu Lake resulting in eutrophication. Among the land use types, paddy fields have some of the highest maximum values and variation of coefficients. Subwatershed scale soil available phosphorus was significantly affected by elevation, slope, precipitation, percentage of cultivated land and percentage of forest land and was decided by not only these environmental factors but also some other factors such as artificial phosphorus fertilizer application. PMID:21909308
Modeling the impact of agricultural land use and management on US carbon budgets
Drewniak, B. A.; Mishra, U.; Song, J.; ...
2015-04-09
Cultivation of the terrestrial land surface can create either a source or sink of atmospheric CO₂, depending on land management practices. The Community Land Model (CLM) provides a useful tool for exploring how land use and management impact the soil carbon pool at regional to global scales. CLM was recently updated to include representation of managed lands growing maize, soybean, and spring wheat. In this study, CLM-Crop is used to investigate the impacts of various management practices, including fertilizer use and differential rates of crop residue removal, on the soil organic carbon (SOC) storage of croplands in the continental Unitedmore » States over approximately a 170-year period. Results indicate that total US SOC stocks have already lost over 8 Pg C (10%) due to land cultivation practices (e.g., fertilizer application, cultivar choice, and residue removal), compared to a land surface composed of native vegetation (i.e., grasslands). After long periods of cultivation, individual subgrids (the equivalent of a field plot) growing maize and soybean lost up to 65% of the carbon stored compared to a grassland site. Crop residue management showed the greatest effect on soil carbon storage, with low and medium residue returns resulting in additional losses of 5 and 3.5%, respectively, in US carbon storage, while plots with high residue returns stored 2% more carbon. Nitrogenous fertilizer can alter the amount of soil carbon stocks significantly. Under current levels of crop residue return, not applying fertilizer resulted in a 5% loss of soil carbon. Our simulations indicate that disturbance through cultivation will always result in a loss of soil carbon, and management practices will have a large influence on the magnitude of SOC loss.« less
2014-03-05
CAPE CANAVERAL, Fla. – Engineers and technicians prepare the Project Morpheus prototype lander for its sixth free flight test from a launch pad at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-03-05
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander begins to ascend on its sixth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-03-05
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander soars high after launching on its sixth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-03-05
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander soars high and moves forward after launching on its sixth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-03-05
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander begins to ascend on its sixth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Frankie Martin
2014-03-05
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander soars high after launching on its sixth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Frankie Martin
2014-03-05
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander begins to ascend on its sixth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Frankie Martin
2014-03-05
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander soars high after launching on its sixth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-03-05
CAPE CANAVERAL, Fla. – Engineers and technicians prepare the Project Morpheus prototype lander for its sixth free flight test from a launch pad at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-03-05
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander soars high after launching on its sixth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Frankie Martin
2014-03-05
CAPE CANAVERAL, Fla. – The Project Morpheus prototype lander ascends on its sixth free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Frankie Martin
2014-03-05
CAPE CANAVERAL, Fla. – Engineers and technicians prepare the Project Morpheus prototype lander for its sixth free flight test from a launch pad at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 82-second test began at 11:32 a.m. EST with the Morpheus lander launching from the ground over a flame trench and ascending to 465 feet. The lander flew forward, covering 633 feet while performing a 55-foot divert to emulate a hazard avoidance maneuver before descending and landing on a dedicated pad inside the automated landing and hazard avoidance technology, or ALHAT, hazard field. Morpheus landed 10 inches west of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
NASA Technical Reports Server (NTRS)
Blankenship, Clay B.; Crosson, William L.; Case, Jonathan L.; Hale, Robert
2010-01-01
Improve simulations of soil moisture/temperature, and consequently boundary layer states and processes, by assimilating AMSR-E soil moisture estimates into a coupled land surface-mesoscale model Provide a new land surface model as an option in the Land Information System (LIS)
The impact of land and sea surface variations on the Delaware sea breeze at local scales
NASA Astrophysics Data System (ADS)
Hughes, Christopher P.
The summertime climate of coastal Delaware is greatly influenced by the intensity, frequency, and location of the local sea breeze circulation. Sea breeze induced changes in temperature, humidity, wind speed, and precipitation influence many aspects of Delaware's economy by affecting tourism, farming, air pollution density, energy usage, and the strength, and persistence of Delaware's wind resource. The sea breeze front can develop offshore or along the coastline and often creates a near surface thermal gradient in excess of 5°C. The purpose of this dissertation is to investigate the dynamics of the Delaware sea breeze with a focus on the immediate coastline using observed and modeled components, both at high resolutions (~200m). The Weather Research and Forecasting model (version 3.5) was employed over southern Delaware with 5 domains (4 levels of nesting), with resolutions ranging from 18km to 222m, for June 2013 to investigate the sensitivity of the sea breeze to land and sea surface variations. The land surface was modified in the model to improve the resolution, which led to the addition of land surface along the coastline and accounted for recent urban development. Nine-day composites of satellite sea surface temperatures were ingested into the model and an in-house SST forcing dataset was developed to account for spatial SST variation within the inland bays. Simulations, which include the modified land surface, introduce a distinct secondary atmospheric circulation across the coastline of Rehoboth Bay when synoptic offshore wind flow is weak. Model runs using high spatial- and temporal-resolution satellite sea surface temperatures over the ocean indicate that the sea breeze landfall time is sensitive to the SST when the circulation develops offshore. During the summer of 2013 a field campaign was conducted in the coastal locations of Rehoboth Beach, DE and Cape Henlopen, DE. At each location, a series of eleven small, autonomous thermo-sensors (i-buttons) were placed along 1-km transects oriented perpendicular to the coastline where each sensor recorded temperatures at five-minute intervals. This novel approach allows for detailed characterization of the sea breeze front development over the immediate coastline not seen in previous studies. These observations provide evidence of significant variability in frontal propagation (advancing, stalling, and retrograding) within the first kilometer of the coast. Results from this observational study indicate that the land surface has the largest effect on the frontal location when the synoptic winds have a strong offshore component, which forces the sea breeze front to move slowly through the region. When this happens, the frequency of occurrence and sea breeze frontal speed decreases consistently across the first 500 m of Rehoboth Beach, after which, the differences become insignificant. At Cape Henlopen the decrease in intensity across the transect is much less evident and the reduction in frequency does not occur until after the front is 500 m from the coast. Under these conditions at Rehoboth Beach, the near surface air behind the front warms due to the land surface which, along with the large surface friction component of the urbanized land surface, causes the front to slow as it traverses the region. Observation and modeling results suggest that the influence of variations in the land and sea surface on the sea breeze circulation is complex and highly dependent on the regional synoptic wind regime. This result inspired the development of a sea breeze prediction algorithm using a generalized linear regression model which, incorporated real-time synoptic conditions to forecast the likelihood of a sea breeze front passing through a coastal station. The forecast skill increases through the morning hours after sunrise. The inland synoptic wind direction is the most influential variable utilized by the algorithm. Such a model could be enhanced to forecast local temperature with coonfidence, which could be useful in an economic or energy usage model.
2014-03-11
CAPE CANAVERAL, Fla. - The Project Morpheus prototype lander soars high on its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Mike Chambers
2014-03-11
CAPE CANAVERAL, Fla. - The Project Morpheus prototype lander soars high on its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Mike Chambers
2014-03-11
CAPE CANAVERAL, Fla. - The Project Morpheus prototype lander soars high on its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Mike Chambers
Morpheus 1C preps & post launch activities
2014-03-11
CAPE CANAVERAL, Fla. - Technicians prepare the Project Morpheus prototype lander for its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
Morpheus 1C preps & post launch activities
2014-03-11
CAPE CANAVERAL, Fla. - Engineers and technicians prepare the Project Morpheus prototype lander for its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-03-11
CAPE CANAVERAL, Fla. - The Project Morpheus prototype lander soars high on its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Mike Chambers
Morpheus 1C preps & post launch activities
2014-03-11
CAPE CANAVERAL, Fla. - Preparations are underway to prepare the Project Morpheus prototype lander for its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
Morpheus 1C preps & post launch activities
2014-03-11
CAPE CANAVERAL, Fla. - The Project Morpheus prototype lander is transported to the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida for the seventh free flight test. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-03-11
CAPE CANAVERAL, Fla. - The Project Morpheus prototype lander begins to ascend on its seventh free flight test at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet, its highest to date. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Mike Chambers
NASA Technical Reports Server (NTRS)
Dong, D,; Gross, R.S.; Dickey, J.
1996-01-01
Monthly mean gravitational field parameters (denoted here as C(sub even)) that represent linear combinations of the primarily even degree zonal spherical harmonic coefficients of the Earth's gravitational field have been recovered using LAGEOS I data and are compared with those derived from gridded global surface pressure data of the National meteorological center (NMC) spanning 1983-1992. The effect of equilibrium ocean tides and surface water variations are also considered. Atmospheric pressure and surface water fluctuations are shown to be the dominant cause of observed annual C(sub even) variations. Closure with observations is seen at the 1sigma level when atmospheric pressure, ocean tide and surface water effects are include. Equilibrium ocean tides are shown to be the main source of excitation at the semiannual period with closure at the 1sigma level seen when both atmospheric pressure and ocean tide effects are included. The inverted barometer (IB) case is shown to give the best agreement with the observation series. The potential of the observed C(sub even) variations for monitoring mass variations in the polar regions of the Earth and the effect of the land-ocean mask in the IB calculation are discussed.
100-OL-1 Operable Unit Pilot Study: XRF Evaluation of Select Pre-Hanford Orchards
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bunn, Amoret L.; Fritz, Brad G.; Pulsipher, Brent A.
Prior to the acquisition of land by the U.S. Department of War in February 1943 and the creation of the Hanford Site, the land along the Columbia River was home to over 1000 people. Farming and orchard operations by both homesteaders and commercial organizations were prevalent. Orchard activities and the associated application of lead arsenate pesticide ceased in 1943, when residents were moved from the Hanford Site at the beginning of the Manhattan Project. Today, the residues from historical application of lead arsenate pesticide persist in some locations on the Hanford Site. In 2012, the U.S. Department of Energy, U.S.more » Environmental Protection Agency, and Washington State Department of Ecology established the 100-OL-1 Operable Unit (OU) through the Hanford Federal Facility Agreement and Consent Order, known as the Tri-Party Agreement. The pre-Hanford orchard lands identified as the 100-OL-1 OU are located south of the Columbia River and east of the present-day Vernita Bridge, and extend southeast to the former Hanford townsite. The discontinuous orchard lands within 100-OL-1 OU are approximately 20 km2 (5000 ac). A pilot study was conducted to support the approval of the remedial investigation/feasibility study work plan to evaluate the 100-OL-1 OU. This pilot study evaluated the use of a field portable X-ray fluorescence (XRF) analyzer for evaluating lead and arsenic concentrations on the soil surface as an indicator of lead arsenate pesticide residues in the OU. The objectives of the pilot study included evaluating a field portable XRF analyzer as the analytical method for decision making, estimating the nature and extent of lead and arsenic in surface soils in four decision units, evaluating the results for the purpose of optimizing the sampling approach implemented in the remedial investigation, and collecting information to improve the cost estimate and planning the cultural resources review for sampling activities in the remedial investigation. Based on the results of the pilot study, the recommendations for the revision of the work plan are as follows: • characterize the surface soil using field portable XRF measurements with confirmatory inductively coupled plasma mass spectroscopy sampling for the remedial investigation • establish decision units of similar defined areas • establish a process for field investigation of soil concentrations exceeding the screening criteria at the border of the 100-OL-1 OU • define data quality objectives for the work plan using the results of the pilot study and refining the sampling approach for the remedial investigation.« less
Effect of climate change on runoff of Campylobacter and Cryptosporidium from land to surface water.
Sterk, Ankie; Schijven, Jack; de Roda Husman, Ana Maria; de Nijs, Ton
2016-05-15
Faeces originating from wildlife, domestic animals or manure-fertilized fields, is considered an important source of zoonotic pathogens to which people may be exposed by, for instance, bathing or drinking-water consumption. An increase in runoff, and associated wash-off of animal faeces from fields, is assumed to contribute to the increase of disease outbreaks during periods of high precipitation. Climate change is expected to increase winter precipitation and extreme precipitation events during summer, but has simultaneously also other effects such as temperature rise and changes in evapotranspiration. The question is to what extent the combination of these effects influence the input of zoonotic pathogens to the surface waters. To quantitatively analyse the impacts of climate change on pathogen runoff, pathogen concentrations reaching surface waters through runoff were calculated by combining an input model for catchment pathogen loads with the Wageningen Lowland Runoff Simulator (WALRUS). Runoff of Cryptosporidium and Campylobacter was evaluated under different climate change scenarios and by applying different scenarios for sources of faecal pollution in the catchments, namely dairy cows and geese and manure fertilization. Model evaluation of these scenarios shows that climate change has little overall impact on runoff of Campylobacter and Cryptosporidium from land to the surface waters. Even though individual processes like runoff fluxes, pathogen release and dilution are affected, either positively or negatively, the net effect on the pathogen concentration in surface waters and consequently also on infection risks through recreation seems limited. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
NASA Astrophysics Data System (ADS)
Farhadi, L.; Abdolghafoorian, A.
2015-12-01
The land surface is a key component of climate system. It controls the partitioning of available energy at the surface between sensible and latent heat, and partitioning of available water between evaporation and runoff. Water and energy cycle are intrinsically coupled through evaporation, which represents a heat exchange as latent heat flux. Accurate estimation of fluxes of heat and moisture are of significant importance in many fields such as hydrology, climatology and meteorology. In this study we develop and apply a Bayesian framework for estimating the key unknown parameters of terrestrial water and energy balance equations (i.e. moisture and heat diffusion) and their uncertainty in land surface models. These equations are coupled through flux of evaporation. The estimation system is based on the adjoint method for solving a least-squares optimization problem. The cost function consists of aggregated errors on state (i.e. moisture and temperature) with respect to observation and parameters estimation with respect to prior values over the entire assimilation period. This cost function is minimized with respect to parameters to identify models of sensible heat, latent heat/evaporation and drainage and runoff. Inverse of Hessian of the cost function is an approximation of the posterior uncertainty of parameter estimates. Uncertainty of estimated fluxes is estimated by propagating the uncertainty for linear and nonlinear function of key parameters through the method of First Order Second Moment (FOSM). Uncertainty analysis is used in this method to guide the formulation of a well-posed estimation problem. Accuracy of the method is assessed at point scale using surface energy and water fluxes generated by the Simultaneous Heat and Water (SHAW) model at the selected AmeriFlux stations. This method can be applied to diverse climates and land surface conditions with different spatial scales, using remotely sensed measurements of surface moisture and temperature states
Yang, Jie; Tang, Chongjun; Chen, Lihua; Liu, Yaojun; Wang, Lingyun
2017-01-01
Rainfall patterns and land cover are two important factors that affect the runoff generation process. To determine the surface and subsurface flows associated with different rainfall patterns on sloping Ferralsols under different land cover types, observational data related to surface and subsurface flows from 5 m × 15 m plots were collected from 2010 to 2012. The experiment was conducted to assess three land cover types (grass, litter cover and bare land) in the Jiangxi Provincial Soil and Water Conservation Ecological Park. During the study period, 114 natural rainfall events produced subsurface flow and were divided into four groups using k-means clustering according to rainfall duration, rainfall depth and maximum 30-min rainfall intensity. The results showed that the total runoff and surface flow values were highest for bare land under all four rainfall patterns and lowest for the covered plots. However, covered plots generated higher subsurface flow values than bare land. Moreover, the surface and subsurface flows associated with the three land cover types differed significantly under different rainfall patterns. Rainfall patterns with low intensities and long durations created more subsurface flow in the grass and litter cover types, whereas rainfall patterns with high intensities and short durations resulted in greater surface flow over bare land. Rainfall pattern I had the highest surface and subsurface flow values for the grass cover and litter cover types. The highest surface flow value and lowest subsurface flow value for bare land occurred under rainfall pattern IV. Rainfall pattern II generated the highest subsurface flow value for bare land. Therefore, grass or litter cover are able to convert more surface flow into subsurface flow under different rainfall patterns. The rainfall patterns studied had greater effects on subsurface flow than on total runoff and surface flow for covered surfaces, as well as a greater effect on surface flows associated with bare land. PMID:28792507
Effect of water table dynamics on land surface hydrologic memory
NASA Astrophysics Data System (ADS)
Lo, Min-Hui; Famiglietti, James S.
2010-11-01
The representation of groundwater dynamics in land surface models has received considerable attention in recent years. Most studies have found that soil moisture increases after adding a groundwater component because of the additional supply of water to the root zone. However, the effect of groundwater on land surface hydrologic memory (persistence) has not been explored thoroughly. In this study we investigate the effect of water table dynamics on National Center for Atmospheric Research Community Land Model hydrologic simulations in terms of land surface hydrologic memory. Unlike soil water or evapotranspiration, results show that land surface hydrologic memory does not always increase after adding a groundwater component. In regions where the water table level is intermediate, land surface hydrologic memory can even decrease, which occurs when soil moisture and capillary rise from groundwater are not in phase with each other. Further, we explore the hypothesis that in addition to atmospheric forcing, groundwater variations may also play an important role in affecting land surface hydrologic memory. Analyses show that feedbacks of groundwater on land surface hydrologic memory can be positive, negative, or neutral, depending on water table dynamics. In regions where the water table is shallow, the damping process of soil moisture variations by groundwater is not significant, and soil moisture variations are mostly controlled by random noise from atmospheric forcing. In contrast, in regions where the water table is very deep, capillary fluxes from groundwater are small, having limited potential to affect soil moisture variations. Therefore, a positive feedback of groundwater to land surface hydrologic memory is observed in a transition zone between deep and shallow water tables, where capillary fluxes act as a buffer by reducing high-frequency soil moisture variations resulting in longer land surface hydrologic memory.
Effects of Topography-based Subgrid Structures on Land Surface Modeling
NASA Astrophysics Data System (ADS)
Tesfa, T. K.; Ruby, L.; Brunke, M.; Thornton, P. E.; Zeng, X.; Ghan, S. J.
2017-12-01
Topography has major control on land surface processes through its influence on atmospheric forcing, soil and vegetation properties, network topology and drainage area. Consequently, accurate climate and land surface simulations in mountainous regions cannot be achieved without considering the effects of topographic spatial heterogeneity. To test a computationally less expensive hyper-resolution land surface modeling approach, we developed topography-based landunits within a hierarchical subgrid spatial structure to improve representation of land surface processes in the ACME Land Model (ALM) with minimal increase in computational demand, while improving the ability to capture the spatial heterogeneity of atmospheric forcing and land cover influenced by topography. This study focuses on evaluation of the impacts of the new spatial structures on modeling land surface processes. As a first step, we compare ALM simulations with and without subgrid topography and driven by grid cell mean atmospheric forcing to isolate the impacts of the subgrid topography on the simulated land surface states and fluxes. Recognizing that subgrid topography also has important effects on atmospheric processes that control temperature, radiation, and precipitation, methods are being developed to downscale atmospheric forcings. Hence in the second step, the impacts of the subgrid topographic structure on land surface modeling will be evaluated by including spatial downscaling of the atmospheric forcings. Preliminary results on the atmospheric downscaling and the effects of the new spatial structures on the ALM simulations will be presented.
Application of ground-penetrating-radar methods in hydrogeologic studies
Beres, Milan; Haeni, F.P.
1991-01-01
A ground-penetrating-radar system was used to study selected stratified-drift deposits in Connecticut. Ground-penetrating radar is a surface-geophysical method that depends on the emission, transmission, reflection, and reception of an electromagnetic pulse and can produce continuous high-resolution profiles of the subsurface rapidly and efficiently. Traverse locations on land included a well field in the town of Mansfield, a sand and gravel pit and a farm overlying a potential aquifer in the town of Coventry, and Haddam Meadows State Park in the town of Haddam. Traverse locations on water included the Willimantic River in Coventry and Mansfield Hollow Lake in Mansfield. The penetration depth of the radar signal ranged from about 20 feet in fine-grained glaciolacustrine sediments to about 70 feet in coarse sand and gravel. Some land records in coarse-grained sediments show a distinct, continuous reflection from the water table about 5 to 11 feet below land surface. Parallel reflectors on the records are interpreted as fine-grained sediments. Hummocky or chaotic reflectors are interpreted as cross-bedded or coarse-grained sediments. Other features observed on some of the radar records include the till and bedrock surface. Records collected on water had distinct water-bottom multiples (more than one reflection) and diffraction patterns from boulders. The interpretation of the radar records, which required little or no processing, was verified by using lithologic logs from test holes located along some of the land traverses and near the water traverses.
Morpheus Alhat Integrated and Laser Test
2014-03-21
CAPE CANAVERAL, Fla. – Engineers and technicians prepare the Project Morpheus prototype lander for an automated landing and hazard avoidance technology, or ALHAT, and laser test at a new launch site at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The launch pad was moved to a different location at the landing facility to support the next phase of flight testing. The seventh free flight test of Morpheus occurred on March 11. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
Morpheus Alhat Integrated and Laser Test
2014-03-21
CAPE CANAVERAL, Fla. – Engineers run an automated landing and hazard avoidance technology, or ALHAT, and laser test on the Project Morpheus prototype lander at a new launch site at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The launch pad was moved to a different location at the landing facility to support the next phase of flight testing. The seventh free flight test of Morpheus occurred on March 11. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Kim Shiflett
2014-03-14
CAPE CANAVERAL, Fla. – Construction workers assist as a crane lowers a portion of the launch pad for the Project Morpheus prototype lander onto a transporter at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The launch pad is being moved to a different location at the landing facility to support the next phase of flight testing. Morpheus completed its seventh free flight test on March 11. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Dimitri Gerondidakis
2014-03-14
CAPE CANAVERAL, Fla. – Construction workers assist as a crane lowers a large portion of the launch pad for the Project Morpheus prototype lander onto a transporter at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The launch pad is being moved to a different location at the landing facility to support the next phase of flight testing. Morpheus completed its seventh free flight test on March 11. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Dimitri Gerondidakis
2014-03-14
CAPE CANAVERAL, Fla. – Construction workers attach a crane to part of the launch pad for the Project Morpheus prototype lander at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The launch pad will be moved to a different location at the landing facility to support the next phase of flight testing. The seventh free flight test of Morpheus occurred on March 11. The 83-second test began at 3:41 p.m. EDT with the Morpheus lander launching from the ground over a flame trench and ascending to 580 feet. Morpheus then flew its fastest downrange trek at 30 mph, travelling farther than before, 837 feet. The lander performed a 42-foot divert to emulate a hazard avoidance maneuver before descending and touching down on Landing Site 2, at the northern landing pad inside the automated landing and hazard avoidance technology ALHAT hazard field. Morpheus landed within one foot of its intended target. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://morpheuslander.jsc.nasa.gov/. Photo credit: NASA/Dimitri Gerondidakis
2014-01-21
CAPE CANAVERAL, Fla. – Technicians monitor the progress as a crane lowers the Project Morpheus prototype for positioning on a launch pad at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The prototype lander is being prepared for its fourth free flight test at Kennedy. Morpheus will launch from the ground over a flame trench and then descend and land on a dedicated pad inside the autonomous landing and hazard avoidance technology, or ALHAT, hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://www.nasa.gov/centers/johnson/exploration/morpheus. Photo credit: NASA/Cory Huston
2014-01-21
CAPE CANAVERAL, Fla. – Technicians and engineers monitor the progress as the Project Morpheus prototype lander is lifted by crane for positioning on a launch pad at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The prototype lander is being prepared for its fourth free flight test at Kennedy. Morpheus will launch from the ground over a flame trench and then descend and land on a dedicated pad inside the autonomous landing and hazard avoidance technology, or ALHAT, hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://www.nasa.gov/centers/johnson/exploration/morpheus. Photo credit: NASA/Cory Huston
2014-01-21
CAPE CANAVERAL, Fla. – Technicians monitor the progress as the Project Morpheus prototype lander is lifted by crane for positioning on a launch pad at the north end of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. The prototype lander is being prepared for its fourth free flight test at Kennedy. Morpheus will launch from the ground over a flame trench and then descend and land on a dedicated pad inside the autonomous landing and hazard avoidance technology, or ALHAT, hazard field. Project Morpheus tests NASA’s ALHAT and an engine that runs on liquid oxygen and methane, or green propellants, into a fully-operational lander that could deliver cargo to other planetary surfaces. The landing facility provides the lander with the kind of field necessary for realistic testing, complete with rocks, craters and hazards to avoid. Morpheus’ ALHAT payload allows it to navigate to clear landing sites amidst rocks, craters and other hazards during its descent. Project Morpheus is being managed under the Advanced Exploration Systems, or AES, Division in NASA’s Human Exploration and Operations Mission Directorate. The efforts in AES pioneer new approaches for rapidly developing prototype systems, demonstrating key capabilities and validating operational concepts for future human missions beyond Earth orbit. For more information on Project Morpheus, visit http://www.nasa.gov/centers/johnson/exploration/morpheus. Photo credit: NASA/Cory Huston
Hassan, Quazi K.; Bourque, Charles P.-A.; Meng, Fan-Rui; Cox, Roger M.
2007-01-01
In this paper we develop a method to estimate land-surface water content in a mostly forest-dominated (humid) and topographically-varied region of eastern Canada. The approach is centered on a temperature-vegetation wetness index (TVWI) that uses standard 8-day MODIS-based image composites of land surface temperature (TS) and surface reflectance as primary input. In an attempt to improve estimates of TVWI in high elevation areas, terrain-induced variations in TS are removed by applying grid, digital elevation model-based calculations of vertical atmospheric pressure to calculations of surface potential temperature (θS). Here, θS corrects TS to the temperature value to what it would be at mean sea level (i.e., ∼101.3 kPa) in a neutral atmosphere. The vegetation component of the TVWI uses 8-day composites of surface reflectance in the calculation of normalized difference vegetation index (NDVI) values. TVWI and corresponding wet and dry edges are based on an interpretation of scatterplots generated by plotting θS as a function of NDVI. A comparison of spatially-averaged field measurements of volumetric soil water content (VSWC) and TVWI for the 2003-2005 period revealed that variation with time to both was similar in magnitudes. Growing season, point mean measurements of VSWC and TVWI were 31.0% and 28.8% for 2003, 28.6% and 29.4% for 2004, and 40.0% and 38.4% for 2005, respectively. An evaluation of the long-term spatial distribution of land-surface wetness generated with the new θS-NDVI function and a process-based model of soil water content showed a strong relationship (i.e., r2 = 95.7%). PMID:28903212
Chen, Liming; Stehouwer, Richard; Tong, Xiaogang; Kost, Dave; Bigham, Jerry M; Dick, Warren A
2015-09-01
Abandoned coal-mined lands are a worldwide concern due to their potential negative environmental impacts, including erosion and development of acid mine drainage. A field study investigated the use of a dry flue gas desulfurization product for reclamation of abandoned coal mined land in USA. Treatments included flue gas desulfurization product at a rate of 280 Mg ha(-1) (FGD), FGD at the same rate plus 112 Mg ha(-1) yard waste compost (FGD/C), and conventional reclamation that included 20 cm of re-soil material plus 157 Mg ha(-1) of agricultural limestone (SOIL). A grass-legume sward was planted after treatment applications. Chemical properties of surface runoff and tile water (collected from a depth of 1.2m below the ground surface) were measured over both short-term (1-4 yr) and long-term (14-20 yr) periods following reclamation. The pH of surface runoff water was increased from approximately 3, and then sustained at 7 or higher by all treatments for up to 20 yr, and the pH of tile flow water was also increased and sustained above 5 for 20 yr. Compared with SOIL, concentrations of Ca, S and B in surface runoff and tile flow water were generally increased by the treatments with FGD product in both short- and long-term measurements and concentrations of the trace elements were generally not statistically increased in surface runoff and tile flow water over the 20-yr period. However, concentrations of As, Ba, Cr and Hg were occasionally elevated. These results suggest the use of FGD product for remediating acidic surface coal mined sites can provide effective, long-term reclamation. Copyright © 2015. Published by Elsevier Ltd.
Land Surface Temperature Measurements from EOS MODIS Data
NASA Technical Reports Server (NTRS)
Wan, Zhengming
1997-01-01
We made modifications to the linear kernel bidirectional reflectance distribution function (BRDF) models from Roujean et al. and Wanner et al. that extend the spectral range into the thermal infrared (TIR). With these TIR BRDF models and the IGBP land-cover product, we developed a classification-based emissivity database for the EOS/MODIS land-surface temperature (LST) algorithm and used it in version V2.0 of the MODIS LST code. Two V2.0 LST codes have been delivered to the MODIS SDST, one for the daily L2 and L3 LST products, and another for the 8-day 1km L3 LST product. New TIR thermometers (broadband radiometer with a filter in the 10-13 micron window) and an IR camera have been purchased in order to reduce the uncertainty in LST field measurements due to the temporal and spatial variations in LST. New improvements have been made to the existing TIR spectrometer in order to increase its accuracy to 0.2 C that will be required in the vicarious calibration of the MODIS TIR bands.
Project 57 Air Monitoring Report: January 1 through December 31, 2015
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mizell, Steve A; Nikolich, George; Shadel, Craig
2017-01-01
On April 24, 1957, the Atomic Energy Commission (AEC, now the Department of Energy [DOE]) conducted the Project 57 safety experiment in western Emigrant Valley north east of the Nevada National Security Site (NNSS, formerly the Nevada Test Site) on lands withdrawn by the Department of Defense (DOD) for the Nevada Test and Training Range (NTTR). The test was undertaken to develop (1) a means of estimating plutonium distribution resulting from a non-nuclear detonation; (2) biomedical evaluation techniques for use in plutonium-laden environments; (3) methods of surface decontamination; and (4) instruments and field procedures for prompt estimation of alpha contaminationmore » (Shreve, 1958). Although the test did not result in the fission of nuclear materials, it did disseminate plutonium across the land surface. Following the experiment, the AEC fenced the contaminated area and returned control of the surrounding land to the DOD. Various radiological surveys were performed in the area and in 2007, the DOE expanded the demarked Contamination Area by posting signs 200 to 400 feet (60 to 120 meters) outside of the original fence.« less
Project 57 Air Monitoring Report: January 1 through December 31, 2016
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mizell, Steve A.; Nikolich, George; Shadel, Craig
On April 24, 1957, the Atomic Energy Commission (AEC, now the Department of Energy [DOE]) conducted the Project 57 safety experiment in western Emigrant Valley northeast of the Nevada National Security Site (NNSS, formerly the Nevada Test Site) on lands withdrawn by the Department of Defense (DOD) for the Nevada Test and Training Range (NTTR). The test was undertaken to develop (1) a means of estimating plutonium distribution resulting from a non-nuclear detonation; (2) biomedical evaluation techniques for use in plutonium-laden environments; (3) methods of surface decontamination; and (4) instruments and field procedures for prompt estimation of alpha contamination (Shreve,more » 1958). Although the test did not result in the fission of nuclear materials, it did disseminate plutonium across the land surface. Following the experiment, the AEC fenced the contaminated area and returned control of the surrounding land to the DOD. Various radiological surveys were performed in the area and in 2007, the DOE expanded the demarked Contamination Area (CA) by posting signs 200 to 400 ft (60 to 120 m) outside of the original fence.« less
Urban Density Indices Using Mean Shift-Based Upsampled Elevetion Data
NASA Astrophysics Data System (ADS)
Charou, E.; Gyftakis, S.; Bratsolis, E.; Tsenoglou, T.; Papadopoulou, Th. D.; Vassilas, N.
2015-04-01
Urban density is an important factor for several fields, e.g. urban design, planning and land management. Modern remote sensors deliver ample information for the estimation of specific urban land classification classes (2D indicators), and the height of urban land classification objects (3D indicators) within an Area of Interest (AOI). In this research, two of these indicators, Building Coverage Ratio (BCR) and Floor Area Ratio (FAR) are numerically and automatically derived from high-resolution airborne RGB orthophotos and LiDAR data. In the pre-processing step the low resolution elevation data are fused with the high resolution optical data through a mean-shift based discontinuity preserving smoothing algorithm. The outcome is an improved normalized digital surface model (nDSM) is an upsampled elevation data with considerable improvement regarding region filling and "straightness" of elevation discontinuities. In a following step, a Multilayer Feedforward Neural Network (MFNN) is used to classify all pixels of the AOI to building or non-building categories. For the total surface of the block and the buildings we consider the number of their pixels and the surface of the unit pixel. Comparisons of the automatically derived BCR and FAR indicators with manually derived ones shows the applicability and effectiveness of the methodology proposed.
Refraction traveltime tomography based on damped wave equation for irregular topographic model
NASA Astrophysics Data System (ADS)
Park, Yunhui; Pyun, Sukjoon
2018-03-01
Land seismic data generally have time-static issues due to irregular topography and weathered layers at shallow depths. Unless the time static is handled appropriately, interpretation of the subsurface structures can be easily distorted. Therefore, static corrections are commonly applied to land seismic data. The near-surface velocity, which is required for static corrections, can be inferred from first-arrival traveltime tomography, which must consider the irregular topography, as the land seismic data are generally obtained in irregular topography. This paper proposes a refraction traveltime tomography technique that is applicable to an irregular topographic model. This technique uses unstructured meshes to express an irregular topography, and traveltimes calculated from the frequency-domain damped wavefields using the finite element method. The diagonal elements of the approximate Hessian matrix were adopted for preconditioning, and the principle of reciprocity was introduced to efficiently calculate the Fréchet derivative. We also included regularization to resolve the ill-posed inverse problem, and used the nonlinear conjugate gradient method to solve the inverse problem. As the damped wavefields were used, there were no issues associated with artificial reflections caused by unstructured meshes. In addition, the shadow zone problem could be circumvented because this method is based on the exact wave equation, which does not require a high-frequency assumption. Furthermore, the proposed method was both robust to an initial velocity model and efficient compared to full wavefield inversions. Through synthetic and field data examples, our method was shown to successfully reconstruct shallow velocity structures. To verify our method, static corrections were roughly applied to the field data using the estimated near-surface velocity. By comparing common shot gathers and stack sections with and without static corrections, we confirmed that the proposed tomography algorithm can be used to correct the statics of land seismic data.
NASA Astrophysics Data System (ADS)
Gronoff, G.; Sullivan, J.; Berkoff, T.; Carrion, W.; Farris, B.
2017-12-01
The NASA Langley Mobile Ozone Lidar (LMOL) and NASA Goddard's lidar (TROPOZ) have routinely measured tropospheric ozone profiles in support of various NASA campaigns and local field studies since 2013 (e.g. DISCOVER-AQ 2014). They are both charter members of the NASA Tropospheric Lidar Network (TOLNet) and were constructed within transportable containers, allowing for observations directly within a variety of complex environments. To gain a better understanding of ozone's interactions close to the surface, both of these instruments have recently designed and optimized near field optical elements for ozone detection. One of the major difficulties for the modeling and satellite communities are the sharp transition regions, both horizontal and vertical, such as the land-water gradients in O3 near coastal/urban regions that are driven by differences in surface deposition, boundary layer height, and cloud coverage.To better understand these gradients, both lidars were deployed in the Hampton Roads / Tidewater region, in Virginia, in July-August 2017, in the context of the OWLETS (Ozone Water Land Environment Transition Study) campaign. The TROPOZ lidar was deployed above land at NASA LaRC, while the LMOL lidar was deployed on the Chesapeake Bay Bridge Tunnel third island, being de-facto an over-water lidar. The distance between the two lidars was approximately 30 km. Strong differences between the two lidars measurements were observed. Some influence of the ship traffic can be seen over water, but does not affect the observations above 300m. Overall, some important discrepancies between the modeling and the lidar observations over water were found. These results shows the importance of making more measurements over water to better constrain pollution models.
NASA Astrophysics Data System (ADS)
Naftz, D. L.; Walton-Day, K. E.; Fuller, C.; Dam, W. L.; Briggs, M. A.; Snyder, T.
2015-12-01
Legacy uranium (U) mining and processing activities have resulted in soil and water contamination on Federal, state, and tribal lands in the western United States. Sites include legacy mill sites associated with U extraction now managed by the Department of Energy and thousands of waste dumps associated with U exploration, mining, and processing. Recently (2012), over 400,000 hectares of federally managed land in northern Arizona was withdrawn from consideration of mining for a 20-year period to protect the Grand Canyon watershed from potentially adverse effects of U mineral exploration and development. Ore from active and recently active U mines in the Colorado Plateau, the Henry Mountains Complex, and the Arizona Strip is transported to the only currently (2015) active conventional mill site in the western United States, located in Utah. Previous and ongoing U.S. Geological Survey assessments to examine U mobility at a variety of legacy and active sites associated with ore exploration, extraction, and processing will be presented as field-scale examples. Topics associated with site investigations will include: (1) offsite migration of radionuclides associated with the operation of the White Mesa U mill; (2) long-term contaminant transport from legacy U waste dumps on Bureau of Land Management regulated land in Utah; (3) application of incremental soil sampling techniques to determine pre- and post-mining radionuclide levels associated with planned and operating U mines in northern Arizona; (4) application of fiber optic digital temperature sensing equipment to identify areas where shallow groundwater containing elevated U levels may be discharging to a river adjacent to a reclaimed mill site in central Wyoming; and (5) field-scale manipulation of groundwater chemistry to limit U migration from a legacy upgrader site in southeastern Utah.
Why the predictions for monsoon rainfall fail?
NASA Astrophysics Data System (ADS)
Lee, J.
2016-12-01
To be in line with the Global Land/Atmosphere System Study (GLASS) of the Global Energy and Water Cycle Experiment (GEWEX) international research scheme, this study discusses classical arguments about the feedback mechanisms between land surface and precipitation to improve the predictions of African monsoon rainfall. In order to clarify the impact of antecedent soil moisture on subsequent rainfall evolution, several data sets will be presented. First, in-situ soil moisture field measurements acquired by the AMMA field campaign will be shown together with rain gauge data. This data set will validate various model and satellite data sets such as NOAH land surface model, TRMM rainfall, CMORPH rainfall and HadGEM climate models, SMOS soil moisture. To relate soil moisture with precipitation, two approaches are employed: one approach makes a direct comparison between the spatial distributions of soil moisture as an absolute value and rainfall, while the other measures a temporal evolution of the consecutive dry days (i.e. a relative change within the same soil moisture data set over time) and rainfall occurrences. Consecutive dry days shows consistent results of a negative feedback between soil moisture and rainfall across various data sets, contrary to the direct comparison of soil moisture state. This negative mechanism needs attention, as most climate models usually focus on a positive feedback only. The approach of consecutive dry days takes into account the systematic errors in satellite observations, reminding us that it may cause the misinterpretation to directly compare model with satellite data, due to their difference in data retrievals. This finding is significant, as the climate indices employed by the Intergovernmental Panel on Climate Change (IPCC) modelling archive are based on the atmospheric variable rathr than land.
Marine Atmospheric Surface Layer and Its Application to Electromagnetic Wave Propagation
NASA Astrophysics Data System (ADS)
Wang, Q.
2015-12-01
An important application of the atmospheric surface layer research is to characterize the near surface vertical gradients in temperature and humidity in order to predict radar and radio communication conditions in the environment. In this presentation, we will give an overview of a new research initiative funded under the Office of Naval Research (ONR) Multi-University Research Initiative (MURI): the Coupled Air-Sea Processes and EM Ducting Research (CASPER). The objective is to fully characterize the marine atmospheric boundary layer (MABL) as an electromagnetic (EM) propagation environment with the emphasis of spatial and temporal heterogeneities and surface wave/swell effects, both of which contravene the underlying assumptions of Monin-Obukhov Similarity Theory (MOST) used in coupled environmental forecast models. Furthermore, coastal variability in the inversion atop the MABL presents a challenge to forecast models and also causes practical issues in EM prediction models. These issues are the target of investigation of CASPER. CASPER measurement component includes two major field campaigns: CASPER-East (2015 Duck, NC) and CASPER-West (2018 southern California). This presentation will show the extensive measurements to be made during the CASPER -East field campaign with the focus on the marine atmospheric surface layer measurements with two research vessels, two research aircraft, surface flux buoy, wave gliders, ocean gliders, tethered balloons, and rawinsondes. Unlike previous research on the marine surface layer with the focus on surface fluxes and surface flux parameterization, CASPER field campaigns also emphasize of the surface layer profiles and the validation of the surface layer flux-profile relationship originally derived over land surfaces. Results from CASPER pilot experiment and preliminary results from CASPER-East field campaign will be discussed.
Readout signals calculated for near-field optical pickups with land and groove recording.
Saito, K; Kishima, K; Ichimura, I
2000-08-10
Optical disk readout signals with a solid immersion lens (SIL) and the land-groove recording technique are calculated by use of a simplified vector-diffraction theory. In this method the full vector-diffraction theory is applied to calculate the diffracted light from the initial state of the disk, and the light scattered from the recorded marks is regarded as a perturbation. Using this method, we confirmed that the land-groove recording technique is effective as a means of cross-talk reduction even when the numerical aperture is more than 1. However, the top surface of the disk under the SIL must be flat, or the readout signal from marks recorded on a groove decays when the optical depth of the groove is greater than lambda/8.
NASA Astrophysics Data System (ADS)
Saadatkhah, Nader; Mansor, Shattri; Khuzaimah, Zailani; Asmat, Arnis; Adnan, Noraizam; Adam, Siti Noradzah
2016-09-01
Changing the land cover/ land use has serious environmental impacts affecting the ecosystem in Malaysia. The impact of land cover changes on the environmental functions such as surface water, loss water, and soil moisture is considered in this paper on the Kelantan river basin. The study area at the east coast of the peninsular Malaysia has suffered significant land cover changes in the recent years. The current research tried to assess the impact of land cover changes in the study area focused on the surface water, loss water, and soil moisture from different land use classes and the potential impact of land cover changes on the ecosystem of Kelantan river basin. To simulate the impact of land cover changes on the environmental hydrology characteristics, a deterministic regional modeling were employed in this study based on five approaches, i.e. (1) Land cover classification based on Landsat images; (2) assessment of land cover changes during last three decades; (3) Calculation the rate of water Loss/ Infiltration; (4) Assessment of hydrological and mechanical effects of the land cover changes on the surface water; and (5) evaluation the impact of land cover changes on the ecosystem of the study area. Assessment of land cover impact on the environmental hydrology was computed with the improved transient rainfall infiltration and grid based regional model (Improved-TRIGRS) based on the transient infiltration, and subsequently changes in the surface water, due to precipitation events. The results showed the direct increased in surface water from development area, agricultural area, and grassland regions compared with surface water from other land covered areas in the study area. The urban areas or lower planting density areas tend to increase for surface water during the monsoon seasons, whereas the inter flow from forested and secondary jungle areas contributes to the normal surface water.
NASA Technical Reports Server (NTRS)
Jonathan L. Case; Kumar, Sujay V.; Srikishen, Jayanthi; Jedlovec, Gary J.
2010-01-01
One of the most challenging weather forecast problems in the southeastern U.S. is daily summertime pulse-type convection. During the summer, atmospheric flow and forcing are generally weak in this region; thus, convection typically initiates in response to local forcing along sea/lake breezes, and other discontinuities often related to horizontal gradients in surface heating rates. Numerical simulations of pulse convection usually have low skill, even in local predictions at high resolution, due to the inherent chaotic nature of these precipitation systems. Forecast errors can arise from assumptions within parameterization schemes, model resolution limitations, and uncertainties in both the initial state of the atmosphere and land surface variables such as soil moisture and temperature. For this study, it is hypothesized that high-resolution, consistent representations of surface properties such as soil moisture, soil temperature, and sea surface temperature (SST) are necessary to better simulate the interactions between the surface and atmosphere, and ultimately improve predictions of summertime pulse convection. This paper describes a sensitivity experiment using the Weather Research and Forecasting (WRF) model. Interpolated land and ocean surface fields from a large-scale model are replaced with high-resolution datasets provided by unique NASA assets in an experimental simulation: the Land Information System (LIS) and Moderate Resolution Imaging Spectroradiometer (MODIS) SSTs. The LIS is run in an offline mode for several years at the same grid resolution as the WRF model to provide compatible land surface initial conditions in an equilibrium state. The MODIS SSTs provide detailed analyses of SSTs over the oceans and large lakes compared to current operational products. The WRF model runs initialized with the LIS+MODIS datasets result in a reduction in the overprediction of rainfall areas; however, the skill is almost equally as low in both experiments using traditional verification methodologies. Output from object-based verification within NCAR s Meteorological Evaluation Tools reveals that the WRF runs initialized with LIS+MODIS data consistently generated precipitation objects that better matched observed precipitation objects, especially at higher precipitation intensities. The LIS+MODIS runs produced on average a 4% increase in matched precipitation areas and a simultaneous 4% decrease in unmatched areas during three months of daily simulations.
Translation of Land Surface Model Accuracy and Uncertainty into Coupled Land-Atmosphere Prediction
NASA Technical Reports Server (NTRS)
Santanello, Joseph A.; Kumar, Sujay; Peters-Lidard, Christa D.; Harrison, Kenneth W.; Zhou, Shuija
2012-01-01
Land-atmosphere (L-A) Interactions playa critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface heat and moisture budgets, as well as controlling feedbacks with clouds and precipitation that lead to the persistence of dry and wet regimes. Recent efforts to quantify the strength of L-A coupling in prediction models have produced diagnostics that integrate across both the land and PBL components of the system. In this study, we examine the impact of improved specification of land surface states, anomalies, and fluxes on coupled WRF forecasts during the summers of extreme dry (2006) and wet (2007) land surface conditions in the U.S. Southern Great Plains. The improved land initialization and surface flux parameterizations are obtained through the use of a new optimization and uncertainty estimation module in NASA's Land Information System (US-OPT/UE), whereby parameter sets are calibrated in the Noah land surface model and classified according to a land cover and soil type mapping of the observation sites to the full model domain. The impact of calibrated parameters on the a) spinup of the land surface used as initial conditions, and b) heat and moisture states and fluxes of the coupled WRF Simulations are then assessed in terms of ambient weather and land-atmosphere coupling along with measures of uncertainty propagation into the forecasts. In addition, the sensitivity of this approach to the period of calibration (dry, wet, average) is investigated. Finally, tradeoffs of computational tractability and scientific validity, and the potential for combining this approach with satellite remote sensing data are also discussed.
NASA Technical Reports Server (NTRS)
Epp, Chirold D.; Robertson, Edward A.; Ruthishauser, David K.
2013-01-01
The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project was chartered to develop and mature to a Technology Readiness Level (TRL) of six an autonomous system combining guidance, navigation and control with real-time terrain sensing and recognition functions for crewed, cargo, and robotic planetary landing vehicles. The ALHAT System must be capable of identifying and avoiding surface hazards to enable a safe and accurate landing to within tens of meters of designated and certified landing sites anywhere on a planetary surface under any lighting conditions. This is accomplished with the core sensing functions of the ALHAT system: Terrain Relative Navigation (TRN), Hazard Detection and Avoidance (HDA), and Hazard Relative Navigation (HRN). The NASA plan for the ALHAT technology is to perform the TRL6 closed loop demonstration on the Morpheus Vertical Test Bed (VTB). The first Morpheus vehicle was lost in August of 2012 during free-flight testing at Kennedy Space Center (KSC), so the decision was made to perform a helicopter test of the integrated ALHAT System with the Morpheus avionics over the ALHAT planetary hazard field at KSC. The KSC helicopter tests included flight profiles approximating planetary approaches, with the entire ALHAT system interfaced with all appropriate Morpheus subsystems and operated in real-time. During these helicopter flights, the ALHAT system imaged the simulated lunar terrain constructed in FY2012 to support ALHAT/Morpheus testing at KSC. To the best of our knowledge, this represents the highest fidelity testing of a system of this kind to date. During this helicopter testing, two new Morpheus landers were under construction at the Johnson Space Center to support the objective of an integrated ALHAT/Morpheus free-flight demonstration. This paper provides an overview of this helicopter flight test activity, including results and lessons learned, and also provides an overview of recent integrated testing of ALHAT on the second Morpheus vehicle.
NASA Technical Reports Server (NTRS)
Rutishauser, David; Epp, Chirold; Robertson, Edward
2013-01-01
The Autonomous Landing Hazard Avoidance Technology (ALHAT) Project was chartered to develop and mature to a Technology Readiness Level (TRL) of six an autonomous system combining guidance, navigation and control with real-time terrain sensing and recognition functions for crewed, cargo, and robotic planetary landing vehicles. The ALHAT System must be capable of identifying and avoiding surface hazards to enable a safe and accurate landing to within tens of meters of designated and certified landing sites anywhere on a planetary surface under any lighting conditions. This is accomplished with the core sensing functions of the ALHAT system: Terrain Relative Navigation (TRN), Hazard Detection and Avoidance (HDA), and Hazard Relative Navigation (HRN). The NASA plan for the ALHAT technology is to perform the TRL6 closed loop demonstration on the Morpheus Vertical Test Bed (VTB). The first Morpheus vehicle was lost in August of 2012 during free-flight testing at Kennedy Space Center (KSC), so the decision was made to perform a helicopter test of the integrated ALHAT System with the Morpheus avionics over the ALHAT planetary hazard field at KSC. The KSC helicopter tests included flight profiles approximating planetary approaches, with the entire ALHAT system interfaced with all appropriate Morpheus subsystems and operated in real-time. During these helicopter flights, the ALHAT system imaged the simulated lunar terrain constructed in FY2012 to support ALHAT/Morpheus testing at KSC. To the best of our knowledge, this represents the highest fidelity testing of a system of this kind to date. During this helicopter testing, two new Morpheus landers were under construction at the Johnson Space Center to support the objective of an integrated ALHAT/Morpheus free-flight demonstration. This paper provides an overview of this helicopter flight test activity, including results and lessons learned, and also provides an overview of recent integrated testing of ALHAT on the second Morpheus vehicle.
Xia, Yongqiu; Ti, Chaopu; She, Dongli; Yan, Xiaoyuan
2016-10-01
The effects of land use and land-use changes on river nutrient concentrations are not well understood, especially in the watersheds of developing countries that have a mixed land use of rice paddy fields and developing urban surfaces. Here, we present a three-year study of a paddy agricultural-urban area gradient watershed in southeast China. The annual anthropogenic nitrogen (N) input from the agricultural region to the urban region was high, yet the results showed that the monthly nutrient concentrations in the river were low in the rainy seasons. The nutrient concentrations decreased continuously as the river water passed through the traditional agriculture region (TAR; paddy rice and wheat rotation) and increased substantially in the city region (CR). The traditional agricultural reference region exported most of the nutrient loads at high flows (>1mmd(-1)), the intensified agricultural region (IAR, aquaculture and poultry farming) exported most of the nutrient loads at moderate flows (between 0.5 and 1mmd(-1)), and the CR reference area exported most of the nutrient loads under low to moderate flows. We developed a statistical model to link variations in the nutrient concentrations to the proportion of land-use types and rainfall. The statistical results showed that impervious surfaces, which we interpret as a proxy for urban activities including sewage disposal, were the most important drivers of nutrient concentrations, whereas water surfaces accounted for a substantial proportion of the nutrient sinks. Therefore, to efficiently reduce water pollution, sewage from urban areas must be addressed as a priority, although wetland restoration could also achieve substantial pollutant removal. Copyright © 2016. Published by Elsevier B.V.