Science.gov

Sample records for advanced land surface

  1. Global scale hydrology - Advances in land surface modeling

    SciTech Connect

    Wood, E.F. )

    1991-01-01

    Research into global scale hydrology is an expanding area that includes researchers from the meteorology, climatology, ecology and hydrology communities. This paper reviews research in this area carried out in the United States during the last IUGG quadrennial period of 1987-1990. The review covers the representation of land-surface hydrologic processes for general circulation models (GCMs), sensitivity analysis of these representations on global hydrologic fields like precipitation, regional studies of climate that have global hydrologic implications, recent field studies and experiments whose aims are the improved understanding of land surface-atmospheric interactions, and the use of remotely sensed data for the further understanding of the spatial variability of surface hydrologic processes that are important at regional and global climate scales. 76 refs.

  2. Land Surface Microwave Emissivities Derived from AMSR-E and MODIS Measurements with Advanced Quality Control

    NASA Technical Reports Server (NTRS)

    Moncet, Jean-Luc; Liang, Pan; Galantowicz, John F.; Lipton, Alan E.; Uymin, Gennady; Prigent, Catherine; Grassotti, Christopher

    2011-01-01

    A microwave emissivity database has been developed with data from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) and with ancillary land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the same Aqua spacecraft. The primary intended application of the database is to provide surface emissivity constraints in atmospheric and surface property retrieval or assimilation. An additional application is to serve as a dynamic indicator of land surface properties relevant to climate change monitoring. The precision of the emissivity data is estimated to be significantly better than in prior databases from other sensors due to the precise collocation with high-quality MODIS LST data and due to the quality control features of our data analysis system. The accuracy of the emissivities in deserts and semi-arid regions is enhanced by applying, in those regions, a version of the emissivity retrieval algorithm that accounts for the penetration of microwave radiation through dry soil with diurnally varying vertical temperature gradients. These results suggest that this penetration effect is more widespread and more significant to interpretation of passive microwave measurements than had been previously established. Emissivity coverage in areas where persistent cloudiness interferes with the availability of MODIS LST data is achieved using a classification-based method to spread emissivity data from less-cloudy areas that have similar microwave surface properties. Evaluations and analyses of the emissivity products over homogeneous snow-free areas are presented, including application to retrieval of soil temperature profiles. Spatial inhomogeneities are the largest in the vicinity of large water bodies due to the large water/land emissivity contrast and give rise to large apparent temporal variability in the retrieved emissivities when satellite footprint locations vary over time. This issue will be dealt with in the future by

  3. Anticipating land surface change.

    PubMed

    Streeter, Richard; Dugmore, Andrew J

    2013-04-01

    The interplay of human actions and natural processes over varied spatial and temporal scales can result in abrupt transitions between contrasting land surface states. Understanding these transitions is a key goal of sustainability science because they can represent abrupt losses of natural capital. This paper recognizes flickering between alternate land surface states in advance of threshold change and critical slowing down in advance of both threshold changes and noncritical transformation. The early warning signals we observe are rises in autocorrelation, variance, and skewness within millimeter-resolution thickness measurements of tephra layers deposited in A.D. 2010 and A.D. 2011. These signals reflect changing patterns of surface vegetation, which are known to provide early warning signals of critical transformations. They were observed toward migrating soil erosion fronts, cryoturbation limits, and expanding deflation zones, thus providing potential early warning signals of land surface change. The record of the spatial patterning of vegetation contained in contemporary tephra layers shows how proximity to land surface change could be assessed in the widespread regions affected by shallow layers of volcanic fallout (those that can be subsumed within the existing vegetation cover). This insight shows how we could use tephra layers in the stratigraphic record to identify "near misses," close encounters with thresholds that did not lead to tipping points, and thus provide additional tools for archaeology, sustainability science, and contemporary land management.

  4. Anticipating land surface change

    PubMed Central

    Streeter, Richard; Dugmore, Andrew J.

    2013-01-01

    The interplay of human actions and natural processes over varied spatial and temporal scales can result in abrupt transitions between contrasting land surface states. Understanding these transitions is a key goal of sustainability science because they can represent abrupt losses of natural capital. This paper recognizes flickering between alternate land surface states in advance of threshold change and critical slowing down in advance of both threshold changes and noncritical transformation. The early warning signals we observe are rises in autocorrelation, variance, and skewness within millimeter-resolution thickness measurements of tephra layers deposited in A.D. 2010 and A.D. 2011. These signals reflect changing patterns of surface vegetation, which are known to provide early warning signals of critical transformations. They were observed toward migrating soil erosion fronts, cryoturbation limits, and expanding deflation zones, thus providing potential early warning signals of land surface change. The record of the spatial patterning of vegetation contained in contemporary tephra layers shows how proximity to land surface change could be assessed in the widespread regions affected by shallow layers of volcanic fallout (those that can be subsumed within the existing vegetation cover). This insight shows how we could use tephra layers in the stratigraphic record to identify “near misses,” close encounters with thresholds that did not lead to tipping points, and thus provide additional tools for archaeology, sustainability science, and contemporary land management. PMID:23530230

  5. Recent Advances in Modeling of the Atmospheric Boundary Layer and Land Surface in the Coupled WRF-CMAQ Model

    EPA Science Inventory

    Advances in the land surface model (LSM) and planetary boundary layer (PBL) components of the WRF-CMAQ coupled meteorology and air quality modeling system are described. The aim of these modifications was primarily to improve the modeling of ground level concentrations of trace c...

  6. Simulating carbon exchange using a regional atmospheric model coupled to an advanced land-surface model

    NASA Astrophysics Data System (ADS)

    Ter Maat, H. W.; Hutjes, R. W. A.; Miglietta, F.; Gioli, B.; Bosveld, F. C.; Vermeulen, A. T.; Fritsch, H.

    2010-08-01

    This paper is a case study to investigate what the main controlling factors are that determine atmospheric carbon dioxide content for a region in the centre of The Netherlands. We use the Regional Atmospheric Modelling System (RAMS), coupled with a land surface scheme simulating carbon, heat and momentum fluxes (SWAPS-C), and including also submodels for urban and marine fluxes, which in principle should include the dominant mechanisms and should be able to capture the relevant dynamics of the system. To validate the model, observations are used that were taken during an intensive observational campaign in central Netherlands in summer 2002. These include flux-tower observations and aircraft observations of vertical profiles and spatial fluxes of various variables. The simulations performed with the coupled regional model (RAMS-SWAPS-C) are in good qualitative agreement with the observations. The station validation of the model demonstrates that the incoming shortwave radiation and surface fluxes of water and CO2 are well simulated. The comparison against aircraft data shows that the regional meteorology (i.e. wind, temperature) is captured well by the model. Comparing spatially explicitly simulated fluxes with aircraft observed fluxes we conclude that in general latent heat fluxes are underestimated by the model compared to the observations but that the latter exhibit large variability within all flights. Sensitivity experiments demonstrate the relevance of the urban emissions of carbon dioxide for the carbon balance in this particular region. The same tests also show the relation between uncertainties in surface fluxes and those in atmospheric concentrations.

  7. Maximizing the Use of Satellite Thermal Infrared Data for Advancing Land Surface Temperature Analysis

    NASA Astrophysics Data System (ADS)

    Weng, Q.; Fu, P.; Gao, F.

    2014-12-01

    Land surface temperature (LST) is a crucial parameter in investigating environmental, ecological processes and climate change at various scales, and is also valuable in the studies of evapotranspiration, soil moisture conditions, surface energy balance, and urban heat islands. These studies require thermal infrared (TIR) images at both high temporal and spatial resolution to retrieve LST. However, currently, no single satellite sensors can deliver TIR data at both high temporal and spatial resolution. Thus, various algorithms/models have been developed to enhance the spatial or the temporal resolution of TIR data, but rare of those can enhance both spatial and temporal details. This paper presents a new data fusion algorithm for producing Landsat-like LST data by blending daily MODIS and periodic Landsat TM datasets. The original Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) was improved and modified for predicting thermal radiance and LST data by considering annual temperature cycle (ATC) and urban thermal landscape heterogeneity. The technique of linear spectral mixture analysis was employed to relate the Landsat radiance with the MODIS one, so that the temporal changes in radiance can be incorporated in the fusion model. This paper details the theoretical basis and the implementation procedures of the proposed data fusion algorithm, Spatio-temporal Adaptive Data Fusion Algorithm for Temperature mapping (SADFAT). A case study was conducted that predicted LSTs of five dates in 2005 from July to October in Los Angeles County, California. The results indicate that the prediction accuracy for the whole study area ranged from 1.3 K to 2 K. Like existing spatio-temporal data fusion models, the SADFAT method has a limitation in predicting LST changes that were not recorded in the MODIS and/or Landsat pixels due to the model assumption.

  8. Land surface interaction

    NASA Technical Reports Server (NTRS)

    Dickinson, Robert E.

    1992-01-01

    The topics covered include the following: land and climate modeling; sensitivity studies; the process of a land model; model-specific parameterizations; water stress; within-canopy resistances; partial vegetation; canopy temperature; and present experience with a land model coupled to a general circulation model.

  9. Advanced Land Imager Assessment System

    NASA Technical Reports Server (NTRS)

    Chander, Gyanesh; Choate, Mike; Christopherson, Jon; Hollaren, Doug; Morfitt, Ron; Nelson, Jim; Nelson, Shar; Storey, James; Helder, Dennis; Ruggles, Tim; Kaita, Ed; Levy, Raviv; Ong, Lawrence; Markham, Brian; Schweiss, Robert

    2008-01-01

    The Advanced Land Imager Assessment System (ALIAS) supports radiometric and geometric image processing for the Advanced Land Imager (ALI) instrument onboard NASA s Earth Observing-1 (EO-1) satellite. ALIAS consists of two processing subsystems for radiometric and geometric processing of the ALI s multispectral imagery. The radiometric processing subsystem characterizes and corrects, where possible, radiometric qualities including: coherent, impulse; and random noise; signal-to-noise ratios (SNRs); detector operability; gain; bias; saturation levels; striping and banding; and the stability of detector performance. The geometric processing subsystem and analysis capabilities support sensor alignment calibrations, sensor chip assembly (SCA)-to-SCA alignments and band-to-band alignment; and perform geodetic accuracy assessments, modulation transfer function (MTF) characterizations, and image-to-image characterizations. ALIAS also characterizes and corrects band-toband registration, and performs systematic precision and terrain correction of ALI images. This system can geometrically correct, and automatically mosaic, the SCA image strips into a seamless, map-projected image. This system provides a large database, which enables bulk trending for all ALI image data and significant instrument telemetry. Bulk trending consists of two functions: Housekeeping Processing and Bulk Radiometric Processing. The Housekeeping function pulls telemetry and temperature information from the instrument housekeeping files and writes this information to a database for trending. The Bulk Radiometric Processing function writes statistical information from the dark data acquired before and after the Earth imagery and the lamp data to the database for trending. This allows for multi-scene statistical analyses.

  10. Land reclamation: Advances in research technology

    SciTech Connect

    Younos, T.; Diplas, P.; Mostaghimi, S.

    1992-01-01

    Land reclamation encompasses remediation of industrial wasteland, improvement of infertile land for agricultural production, preservation of wetlands, and restoration of disturbed areas. Land reclamation is an integral part of sustainable development which aims to reconcile economic productivity with environmental preservation. During the 1980s, significant progress was achieved in the application of advanced technologies to sustainable development projects. The goal of this international symposium was to serve as a forum to review current research and state-of-the-art technology dealing with various aspects of land reclamation, and provide an opportunity for professional interaction and exchange of information in a multi-disciplinary setting. The scope of the symposium was as broad as the topic itself. The keynote address by Professor John Cairns focused on a systems approach in land restoration projects and challenges facing scientists in global biotic impoverishment. Other topics discussed in ten mechanical sessions included development and applications of computer models, geographic information systems, remote sensing technology, salinity problems, surface and ground water monitoring, reclamation of mine areas, soil amendment methods and impacts, wetland restoration techniques, and land use planning for resource protection.

  11. Advancing the Remote Sensing of Land Surface-Atmosphere Interactions: Field Campaign Needs in the Next Decade

    NASA Astrophysics Data System (ADS)

    Hall, F. G.; Sellers, P. J.; Hummerich, K. F.

    2008-12-01

    Field Campaigns have played a vital role in the development of remote sensing measurement techniques and models to observe the changing nature of the Earth's vegetated land surface and to compute the exchange of carbon, water and energy from the vegetated land surface. Importantly, they have pioneered and fostered a culture of interdisciplinary research focusing and integrating the efforts of the hydrology, ecology and remote sensing communities toward the resolution of a critical question for life on the planet earth; How are the Earth's energy, water and carbon cycles changing, and what are the consequences for the Earth's climate, the sustainability of its ecosystems and biodiversity? Not only have the research results from these campaigns contributed substantially to the resolution of this critical question, the interdisciplinary data sets acquired and made easily accessible to the global scientific community, continue to contribute, remaining heavily utilized more than 20 years following the completion of the earliest campaigns. A new generation of earth science satellites is now on the drawing board; in the US to extend the 30+ year data record from the Landsat series; some to extend the data record from NOAA's AVHRR, NASA's Terra and Aqua; and a growing constellation of satellites from Europe, Japan, India and China. In addition to continuing the existing satellite data record, new satellite concepts, utilizing combined radar and lidar measurements, are being designed in the US and abroad to map the earth's vegetation, ice and solid surfaces in three dimensions. These capabilities will permit global mapping of the vertical and horizontal structure of vegetation, critical to measuring biomass and biomass change needed to understand and project future changes in the earth's carbon cycle, climate and biodiversity. New space capabilities require new field campaigns To be effective these campaigns must be formulated with a rigorous experiment design focused on

  12. Remote Sensing Observatory Validation of Surface Soil Moisture Using Advanced Microwave Scanning Radiometer E, Common Land Model, and Ground Based Data: Case Study in SMEX03 Little River Region, Georgia, U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Optimal soil moisture estimation may be characterized by inter-comparisons among remotely sensed measurements, ground-based measurements, and land surface models. In this study, we compared soil moisture from Advanced Microwave Scanning Radiometer E (AMSR-E), ground-based measurements, and Soil-Vege...

  13. Spectroradiometric considerations for advanced land observing systems

    NASA Technical Reports Server (NTRS)

    Slater, P. N.

    1986-01-01

    Research aimed at improving the inflight absolute radiometric calibration of advanced land observing systems was initiated. Emphasis was on the satellite sensor calibration program at White Sands. Topics addressed include: absolute radiometric calibration of advanced remote sensing; atmospheric effects on reflected radiation; inflight radiometric calibration; field radiometric methods for reflectance and atmospheric measurement; and calibration of field relectance radiometers.

  14. Oscillations in land surface hydrological cycle

    NASA Astrophysics Data System (ADS)

    Labat, D.

    2006-02-01

    Hydrological cycle is the perpetual movement of water throughout the various component of the global Earth's system. Focusing on the land surface component of this cycle, the determination of the succession of dry and humid periods is of high importance with respect to water resources management but also with respect to global geochemical cycles. This knowledge requires a specified estimation of recent fluctuations of the land surface cycle at continental and global scales. Our approach leans towards a new estimation of freshwater discharge to oceans from 1875 to 1994 as recently proposed by Labat et al. [Labat, D., Goddéris, Y., Probst, JL, Guyot, JL, 2004. Evidence for global runoff increase related to climate warming. Advances in Water Resources, 631-642]. Wavelet analyses of the annual freshwater discharge time series reveal an intermittent multiannual variability (4- to 8-y, 14- to 16-y and 20- to 25-y fluctuations) and a persistent multidecadal 30- to 40-y variability. Continent by continent, reasonable relationships between land-water cycle oscillations and climate forcing (such as ENSO, NAO or sea surface temperature) are proposed even though if such relationships or correlations remain very complex. The high intermittency of interannual oscillations and the existence of persistent multidecadal fluctuations make prediction difficult for medium-term variability of droughts and high-flows, but lead to a more optimistic diagnostic for long-term fluctuations prediction.

  15. Advanced Space Surface Systems Operations

    NASA Technical Reports Server (NTRS)

    Huffaker, Zachary Lynn; Mueller, Robert P.

    2014-01-01

    The importance of advanced surface systems is becoming increasingly relevant in the modern age of space technology. Specifically, projects pursued by the Granular Mechanics and Regolith Operations (GMRO) Lab are unparalleled in the field of planetary resourcefulness. This internship opportunity involved projects that support properly utilizing natural resources from other celestial bodies. Beginning with the tele-robotic workstation, mechanical upgrades were necessary to consider for specific portions of the workstation consoles and successfully designed in concept. This would provide more means for innovation and creativity concerning advanced robotic operations. Project RASSOR is a regolith excavator robot whose primary objective is to mine, store, and dump regolith efficiently on other planetary surfaces. Mechanical adjustments were made to improve this robot's functionality, although there were some minor system changes left to perform before the opportunity ended. On the topic of excavator robots, the notes taken by the GMRO staff during the 2013 and 2014 Robotic Mining Competitions were effectively organized and analyzed for logistical purposes. Lessons learned from these annual competitions at Kennedy Space Center are greatly influential to the GMRO engineers and roboticists. Another project that GMRO staff support is Project Morpheus. Support for this project included successfully producing mathematical models of the eroded landing pad surface for the vertical testbed vehicle to predict a timeline for pad reparation. And finally, the last project this opportunity made contribution to was Project Neo, a project exterior to GMRO Lab projects, which focuses on rocket propulsion systems. Additions were successfully installed to the support structure of an original vertical testbed rocket engine, thus making progress towards futuristic test firings in which data will be analyzed by students affiliated with Rocket University. Each project will be explained in

  16. The Land Surface Temperature Impact to Land Cover Types

    NASA Astrophysics Data System (ADS)

    Ibrahim, I.; Abu Samah, A.; Fauzi, R.; Noor, N. M.

    2016-06-01

    Land cover type is an important signature that is usually used to understand the interaction between the ground surfaces with the local temperature. Various land cover types such as high density built up areas, vegetation, bare land and water bodies are areas where heat signature are measured using remote sensing image. The aim of this study is to analyse the impact of land surface temperature on land cover types. The objectives are 1) to analyse the mean temperature for each land cover types and 2) to analyse the relationship of temperature variation within land cover types: built up area, green area, forest, water bodies and bare land. The method used in this research was supervised classification for land cover map and mono window algorithm for land surface temperature (LST) extraction. The statistical analysis of post hoc Tukey test was used on an image captured on five available images. A pixel-based change detection was applied to the temperature and land cover images. The result of post hoc Tukey test for the images showed that these land cover types: built up-green, built up-forest, built up-water bodies have caused significant difference in the temperature variation. However, built up-bare land did not show significant impact at p<0.05. These findings show that green areas appears to have a lower temperature difference, which is between 2° to 3° Celsius compared to urban areas. The findings also show that the average temperature and the built up percentage has a moderate correlation with R2 = 0.53. The environmental implications of these interactions can provide some insights for future land use planning in the region.

  17. Advancements in medium and high resolution Earth observation for land-surface imaging: Evolutions, future trends and contributions to sustainable development

    NASA Astrophysics Data System (ADS)

    Ouma, Yashon O.

    2016-01-01

    Technologies for imaging the surface of the Earth, through satellite based Earth observations (EO) have enormously evolved over the past 50 years. The trends are likely to evolve further as the user community increases and their awareness and demands for EO data also increases. In this review paper, a development trend on EO imaging systems is presented with the objective of deriving the evolving patterns for the EO user community. From the review and analysis of medium-to-high resolution EO-based land-surface sensor missions, it is observed that there is a predictive pattern in the EO evolution trends such that every 10-15 years, more sophisticated EO imaging systems with application specific capabilities are seen to emerge. Such new systems, as determined in this review, are likely to comprise of agile and small payload-mass EO land surface imaging satellites with the ability for high velocity data transmission and huge volumes of spatial, spectral, temporal and radiometric resolution data. This availability of data will magnify the phenomenon of "Big Data" in Earth observation. Because of the "Big Data" issue, new computing and processing platforms such as telegeoprocessing and grid-computing are expected to be incorporated in EO data processing and distribution networks. In general, it is observed that the demand for EO is growing exponentially as the application and cost-benefits are being recognized in support of resource management.

  18. Land surface hydrology in the cloud land surface interaction campaign (CLASIC)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A fundamental objective of the Cloud Land Surface Interaction Campaign (CLASIC) was to contribute to our understanding of the interactions between the atmosphere and the land surface. It has been observed that land surface characteristics influence the timing and evolution of cumulus convection. The...

  19. Advancing Lidar Sensors Technologies for Next Generation Landing Missions

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Hines, Glenn D.; Roback, Vincent E.; Petway, Larry B.; Barnes, Bruce W.; Brewster, Paul F.; Pierrottet, Diego F.; Bulyshev, Alexander

    2015-01-01

    Missions to solar systems bodies must meet increasingly ambitious objectives requiring highly reliable "precision landing", and "hazard avoidance" capabilities. Robotic missions to the Moon and Mars demand landing at pre-designated sites of high scientific value near hazardous terrain features, such as escarpments, craters, slopes, and rocks. Missions aimed at paving the path for colonization of the Moon and human landing on Mars need to execute onboard hazard detection and precision maneuvering to ensure safe landing near previously deployed assets. Asteroid missions require precision rendezvous, identification of the landing or sampling site location, and navigation to the highly dynamic object that may be tumbling at a fast rate. To meet these needs, NASA Langley Research Center (LaRC) has developed a set of advanced lidar sensors under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project. These lidar sensors can provide precision measurement of vehicle relative proximity, velocity, and orientation, and high resolution elevation maps of the surface during the descent to the targeted body. Recent flights onboard Morpheus free-flyer vehicle have demonstrated the viability of ALHAT lidar sensors for future landing missions to solar system bodies.

  20. Conceptual Problems in Land Surface Data Assimilation

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf

    2012-01-01

    A land data assimilation system (LDAS) merges observations (or satellite retrievals) of land surface hydrological conditions, including soil moisture, snow, and terrestrial water storage (TWS), into a numerical model of land surface processes. In theory, the output from such a system is superior to estimates based on the observations or the model alone, thereby enhancing our ability to understand, monitor, and predict key elements of the terrestrial water cycle. In practice, however, several conceptual problems can interfere with realizing the potential improvements from data assimilation. Of particular concern is the frequent mismatch between the assimilated observations and the land surface model variables of interest. The seminar will discuss recent research with the ensemble-based NASA GEOS-S LDAS to address various aspects of this mismatch. These aspects include (i) the assimilation of coarse-scale observations into higher-resolution land surface models, (ii) the partitioning of satellite observations (such as TWS retrievals) into their constituent water cycle components, (iii) the forward modeling of microwave brightness temperatures over land for radiance-based land surface data aSSimilation, and (iv) the selection of the most relevant types of observations for the analysis of a specific water cycle variable (such as root zone soil moisture). At its core, the solution to the above challenges involves the careful construction of an observation operator that maps from the land surface model variables of interest to the space of the assimilated observations.

  1. Microwave Brightness Of Land Surfaces From Outer Space

    NASA Technical Reports Server (NTRS)

    Kerr, Yann H.; Njoku, Eni G.

    1991-01-01

    Mathematical model approximates microwave radiation emitted by land surfaces traveling to microwave radiometer in outer space. Applied to measurements made by Scanning Multichannel Microwave Radiometer (SMMR). Developed for interpretation of microwave imagery of Earth to obtain distributions of various chemical, physical, and biological characteristics across its surface. Intended primarily for use in mapping moisture content of soil and fraction of Earth covered by vegetation. Advanced Very-High-Resolution Radiometer (AVHRR), provides additional information on vegetative cover, thereby making possible retrieval of soil-moisture values from SMMR measurements. Possible to monitor changes of land surface during intervals of 5 to 10 years, providing significant data for mathematical models of evolution of climate.

  2. The CEOS constellation for land surface imaging

    USGS Publications Warehouse

    Bailey, G.B.; Berger, M.; Jeanjean, H.; Gallo, K.P.

    2007-01-01

    A constellation of satellites that routinely and frequently images the Earth's land surface in consistently calibrated wavelengths from the visible through the microwave and in spatial detail that ranges from sub-meter to hundreds of meters would offer enormous potential benefits to society. A well-designed and effectively operated land surface imaging satellite constellation could have great positive impact not only on the quality of life for citizens of all nations, but also on mankind's very ability to sustain life as we know it on this planet long into the future. The primary objective of the Committee on Earth Observation Satellites (CEOS) Land Surface Imaging (LSI) Constellation is to define standards (or guidelines) that describe optimal future LSI Constellation capabilities, characteristics, and practices. Standards defined for a LSI Constellation will be based on a thorough understanding of user requirements, and they will address at least three fundamental areas of the systems comprising a Land Surface Imaging Constellation: the space segments, the ground segments, and relevant policies and plans. Studies conducted by the LSI Constellation Study Team also will address current and shorter-term problems and issues facing the land remote sensing community today, such as seeking ways to work more cooperatively in the operation of existing land surface imaging systems and helping to accomplish tangible benefits to society through application of land surface image data acquired by existing systems. 2007 LSI Constellation studies are designed to establish initial international agreements, develop preliminary standards for a mid-resolution land surface imaging constellation, and contribute data to a global forest assessment.

  3. Recent advances in land-atmosphere interaction research

    NASA Astrophysics Data System (ADS)

    Entekhabi, Dara

    1995-07-01

    From the earliest attempt at numerical weather prediction up until today's efforts on improving the land surface hydrologic parameterization in General Circulation models (GCMs), it has been recognized that the realistic characterization of atmospheric phenomena requires accurate representation of surficial processes. Lewis F. Richardson who attempted numerical weather prediction using hand calculations around the First World War period includes, in his notes, a parameterization of the surface evapotranspiration and plant stomatal control of the vapor exchange between land and atmosphere. He writes: "…Let the rate of loss of water from a leaf be denoted by T, thenT=K{ F(θleaf)-wair }here K is the conductance of the stomatal openings and F (θleaf) is the saturated vapour density at θ." [Richardson, 1922]. Almost three-quarters of a century later and using high-speed digital computers, the research community is essentially implementing Lewis F. Richardson's original scheme of stomatal resistance to vapor flux between the saturated interior of leaves at temperature 9ieaf and near-surface air humidity wair. At first sight it may appear that not much scientific progress has been made in the interim years. Transpiration, turbulence and other processes related to land-atmosphere exchange are complex phenomena and in fact there has been significant recent advances in the study of land-atmosphere interaction. The land, biosphere, atmosphere and ocean systems are coupled across a wide range of space and time scales such that each discovery leads to a deeper and larger scientific question. Research inquiry in this area is now performed in both the hydrologic and the atmospheric science communities.

  4. Spatial assessment of land surface temperature and land use/land cover in Langkawi Island

    NASA Astrophysics Data System (ADS)

    Abu Bakar, Suzana Binti; Pradhan, Biswajeet; Salihu Lay, Usman; Abdullahi, Saleh

    2016-06-01

    This study investigates the relationship between Land Surface Temperature and Land Use/Land Cover in Langkawi Island by using Normalized Difference Vegetation Index (NDVI), Normalized Difference Build-Up Index (NDBI) and Modified Normalized Difference Water Index (MNDWI) qualitatively by using Landsat 7 ETM+ and Landsat 8 (OLI/TIRS) over the period 2002 and 2015. Pixel-based classifiers Maximum Likelihood (MLC) and Support Vector Machine (SVM), has been performed to prepare the Land Use/ Land Cover map (LU/LC) and the result shows that Support Vector Machine (SVM) achieved maximum accuracy with 90% and 90.46% compared to Maximum Likelihood (MLC) classifier with 86.62% and 86.98% respectively. The result revealed that as the impervious surface (built-up /roads) increases, the surface temperature of the area increased. However, land surface temperature decreased in the vegetated areas. Based from the linear regression between LST and NDVI, NDBI and MNDWI, these indices can be used as an indicator to monitor the impact of Land Use/Land Cover on Land Surface Temperature.

  5. Upscaling and downscaling of land surface fluxes with surface temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface temperature (LST) is a key surface boundary condition that is significantly correlated to surface flux partitioning between latent and sensible heat. The spatial and temporal variation in LST is driven by radiation, wind, vegetation cover and roughness as well as soil moisture status ...

  6. Geospatial approach for estimating land surface evapotranspiration

    NASA Astrophysics Data System (ADS)

    Singh, Ramesh K.

    Reliably and accurately quantifying evapotranspiration (ET) in a spatial and temporal domain is important in water management at the local, regional, and global scales. With advances in image processing and hardware computational ability, energy balance models which utilize remote sensing images are being increasingly utilized for quantifying ET and used as inputs in hydrologic modeling. The objectives of this research were to evaluate and improve some of the energy balance models for estimating land surface ET, and develop a framework for estimating seasonal ET from temporal satellite images. Surface Energy Balance Algorithm for Land (SEBAL) model was used to estimate energy fluxes for south-central Nebraska using Landsat images. Results were compared with Bowen Ratio Energy Balance System (BREBS) field measurements. SEBAL estimated ET images were also used for computing crop coefficients (K c) for maize, soybean, sorghum, and alfalfa under irrigated and dryland conditions. Performances of four remote sensing based models for estimating soil heat flux (G) were analyzed. A new model was developed for remotely estimating G. The Mapping Evapotranspiration at high Resolution with Internalized Calibration (METRIC) model was also used for estimating energy fluxes using Landsat images. The METRIC model was modified by incorporating the Priestley-Taylor (PT) approach. The SEBAL model estimated net radiation (Rn) with a root mean square error (RMSE) of 65 W m-2 (r2 = 0.76). Calibrating G locally reduced RMSE from 80 W m-2 to 20 W m-2. The SEBAL model yielded sensible heat flux (H) with RMSE of 108 W m -2 (r2=0.23), and ET with an RMSE of 1.04 mm day -1(r2 = 0.73). Validation of Kc regression for irrigated maize resulted in RMSE of 0.21 (r2=0.74). The METRIC model estimated Rn, G, and H with RMSE values of 45 W m -2 (r2=0.85), 19 W m-2 (r2=0.85), and 113 W m-2 (r2=0.50), respectively. The modified METRIC model reduced the RMSE of H from 113 W m-2 to 91 W m -2 and that for

  7. The Continuing Evolution of Land Surface Parameterizations

    NASA Technical Reports Server (NTRS)

    Koster, Randal; Houser, Paul (Technical Monitor)

    2001-01-01

    Land surface models (LSMs) play a critical role in the simulation of climate, for they determine the character of a large fraction of the atmosphere's lower boundary. The LSM partitions the net radiative energy at the land surface into sensible heat, latent heat, and energy storage, and it partitions incident precipitation water into evaporation, runoff, and water storage. Numerous modeling experiments and the existing (though very scant) observational evidence suggest that variations in these partitionings can feed back on the atmospheric processes that induce them. This land-atmosphere feedback can in turn have a significant impact on the generation of continental precipitation. For this and other reasons (including the role of the land surface in converting various atmospheric quantities, such as precipitation, into quantities of perhaps higher societal relevance, such as runoff), many modeling groups are placing a high emphasis on improving the treatment of land surface processes in their models. LSMs have evolved substantially from the original bucket model of Manabe et al. This evolution, which is still ongoing, has been documented considerably. The present paper also takes a look at the evolution of LSMs. The perspective here, though, is different - the evolution is considered strictly in terms of the 'balance' between the formulations of evaporation and runoff processes. The paper will argue that a proper balance is currently missing, largely due to difficulties in treating subgrid variability in soil moisture and its impact on the generation of runoff.

  8. Remote sensing of land surface phenology

    USGS Publications Warehouse

    Meier, G.A.; Brown, J.F.

    2014-01-01

    Remote sensing of land-surface phenology is an important method for studying the patterns of plant and animal growth cycles. Phenological events are sensitive to climate variation; therefore phenology data provide important baseline information documenting trends in ecology and detecting the impacts of climate change on multiple scales. The USGS Remote sensing of land surface phenology program produces annually, nine phenology indicator variables at 250 m and 1,000 m resolution for the contiguous U.S. The 12 year archive is available at http://phenology.cr.usgs.gov/index.php.

  9. A land surface data assimilation framework using the land information system: Description and applications

    NASA Astrophysics Data System (ADS)

    Kumar, Sujay V.; Reichle, Rolf H.; Peters-Lidard, Christa D.; Koster, Randal D.; Zhan, Xiwu; Crow, Wade T.; Eylander, John B.; Houser, Paul R.

    2008-11-01

    The Land Information System (LIS) is an established land surface modeling framework that integrates various community land surface models, ground measurements, satellite-based observations, high performance computing and data management tools. The use of advanced software engineering principles in LIS allows interoperability of individual system components and thus enables assessment and prediction of hydrologic conditions at various spatial and temporal scales. In this work, we describe a sequential data assimilation extension of LIS that incorporates multiple observational sources, land surface models and assimilation algorithms. These capabilities are demonstrated here in a suite of experiments that use the ensemble Kalman filter (EnKF) and assimilation through direct insertion. In a soil moisture experiment, we discuss the impact of differences in modeling approaches on assimilation performance. Provided careful choice of model error parameters, we find that two entirely different hydrological modeling approaches offer comparable assimilation results. In a snow assimilation experiment, we investigate the relative merits of assimilating different types of observations (snow cover area and snow water equivalent). The experiments show that data assimilation enhancements in LIS are uniquely suited to compare the assimilation of various data types into different land surface models within a single framework. The high performance infrastructure provides adequate support for efficient data assimilation integrations of high computational granularity.

  10. Soft Landing of Complex Molecules on Surfaces *

    NASA Astrophysics Data System (ADS)

    Johnson, Grant E.; Hu, Qichi; Laskin, Julia

    2011-07-01

    Soft and reactive landing of mass-selected ions onto surfaces has become a topic of substantial interest due to its promising potential for the highly controlled preparation of materials. For example, there are possible applications in the production of peptide and protein microarrays for use in high-throughput screening, protein separation and conformational enrichment of peptides, redox protein characterization, thin-film production, and the preparation of catalysts through deposition of clusters and organometallic complexes. Soft landing overcomes many of the limitations associated with conventional thin-film production techniques and offers unprecedented selectivity and specificity of preparation of deposited species. This review discusses the fundamental aspects of soft and reactive landing of mass-selected ions on surfaces that pertain to applications of these techniques in biomaterials, molecular electronics, catalysis, and interfacial chemistry.

  11. Observations of Land Surface Variability Using Passive Microwave Sensing

    NASA Technical Reports Server (NTRS)

    Njoku, Eni G.

    1999-01-01

    Understanding the global variability of land surface wetness (soil moisture), skin temperature, and related surface fluxes of heat and moisture is key to assessing the importance of the land surface in influencing climate. The feasibility of producing model estimates of these quantities is being studied as part of the International Satellite Land Surface Climatology Project (ISLSCP) Global Soil Wetness Project (GSWP). In the GSWP approach, meteorological observations and analyses are used to drive global circulation models. Satellite measurements can provide independent estimates of key land surface parameters that are needed for initializing and validating the climate models and for monitoring long-term change. Satellite observations of the land surface can also be assimilated into soil models to estimate moisture in the root zone. In our research, passive microwave satellite data recorded during 1978-1987 from the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) are being used to examine spatial and temporal trends in surface soil moisture, vegetation, and temperature. These data include observations at C and X bands (6.6 and 10.7 GHz), which are not available on the current Special Sensor Microwave/Imager (SSM/I) and are precursors to data that will become available from the Advanced Microwave Scanning Radiometer (AMSR) on Advanced Earth Observing Satellite (ADEOS-II) and Earth Observing System (EOS) PM1 in the year 2000. A chart shows a time-series of SMMR-derived surface temperature, T-e and surface soil moisture M, retrieved on a 0.5 deg x 0.5 deg grid and further averaged over a 4 deg x 10 deg study region in the African Sahel. Also shown are National Center for Environmental Prediction (NCEP) model outputs of surface temperature, T-sfc, and soil wetness, Soil-w. The variables have been scaled to have similar dynamic ranges on the plots. The NCEP data from the NCEP Reanalysis Project are monthly averages on a 2.5 deg x 2.5 deg grid averaged over

  12. 25 CFR 214.14 - Use of surface lands.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Use of surface lands. 214.14 Section 214.14 Indians... LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.14 Use of surface lands. (a) Lessees may use so much of the surface of the leased land as shall be reasonably necessary for the prospecting and...

  13. 25 CFR 214.14 - Use of surface lands.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Use of surface lands. 214.14 Section 214.14 Indians... LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.14 Use of surface lands. (a) Lessees may use so much of the surface of the leased land as shall be reasonably necessary for the prospecting and...

  14. Upscaling and Downscaling of Land Surface Fluxes with Surface Temperature

    NASA Astrophysics Data System (ADS)

    Kustas, W. P.; Anderson, M. C.; Hain, C.; Albertson, J. D.; Gao, F.; Yang, Y.

    2015-12-01

    Land surface temperature (LST) is a key surface boundary condition that is significantly correlated to surface flux partitioning between latent and sensible heat. The spatial and temporal variation in LST is driven by radiation, wind, vegetation cover and roughness as well as soil moisture status in the surface and root zone. Data from airborne and satellite-based platforms provide LST from ~10 km to sub meter resolutions. A land surface scheme called the Two-Source Energy Balance (TSEB) model has been incorporated into a multi-scale regional modeling system ALEXI (Atmosphere Land Exchange Inverse) and a disaggregation scheme (DisALEXI) using higher resolution LST. Results with this modeling system indicates that it can be applied over heterogeneous land surfaces and estimate reliable surface fluxes with minimal in situ information. Consequently, this modeling system allows for scaling energy fluxes from subfield to regional scales in regions with little ground data. In addition, the TSEB scheme has been incorporated into a large Eddy Simulation (LES) model for investigating dynamic interactions between variations in the land surface state reflected in the spatial pattern in LST and the lower atmospheric air properties affecting energy exchange. An overview of research results on scaling of fluxes and interactions with the lower atmosphere from the subfield level to regional scales using the TSEB, ALEX/DisALEX and the LES-TSEB approaches will be presented. Some unresolved issues in the use of LST at different spatial resolutions for estimating surface energy balance and upscaling fluxes, particularly evapotranspiration, will be discussed.

  15. Impact of Soil Moisture Assimilation on Land Surface Model Spinup and Coupled Land-Atmosphere Prediction

    NASA Astrophysics Data System (ADS)

    Santanello, J. A., Jr.; Kumar, S.; Peters-Lidard, C. D.; Lawston, P.

    2015-12-01

    Advances in satellite monitoring of the terrestrial water cycle have led to a concerted effort to assimilate soil moisture observations from various platforms into offline land surface models (LSMs). One principal but still open question is that of the ability of land data assimilation (LDA) to improve LSM initial conditions for coupled short-term weather prediction. In this study, the impact of assimilating Advanced Microwave Scanning Radiometer for EOS (AMSR-E) soil moisture retrievals on coupled WRF forecasts is examined during the summers of dry (2006) and wet (2007) surface conditions in the U.S. Southern Great Plains. LDA is carried out using NASA's Land Information System (LIS) and the Noah LSM using an Ensemble Kalman Filter (EnKF) approach. The impacts of LDA on the a) soil moisture and soil temperature initial conditions for WRF, b) land-atmosphere coupling characteristics, and c) ambient weather of the coupled LIS-WRF simulations are then assessed. Results show that impacts of soil moisture LDA during the spinup can significantly modify LSM states and fluxes, depending on regime and season. Results also quantify the impacts of using seasonal versus cumulative CDF matching and coarse vs. fine-scale atmospheric forcing approaches. Downstream impacts on coupled simulations vary according to the strength of the LDA impact at initialization, and significant modification to the soil moisture-flux-PBL-ambient weather process chain are observed. Overall, improvements due to LDA in this study show promise for future soil moisture assimilation applications in weather and climate.

  16. Comparing different land surface heat flux estimates

    NASA Astrophysics Data System (ADS)

    Tretkoff, Ernie

    2011-04-01

    Land surface heat fluxes are an important component of Earth's energy and water cycle, and quantifying these fluxes can help scientists better understand climate change. These heat fluxes are affected by factors such as cloud cover, precipitation, surface radiation, air temperature, and humidity. Different methods are used to estimate monthly mean land surface heat flux. To determine how well these different methods agree with one other, Jiménez et al. present a detailed global intercomparison of 12 such products for the period 1993-1995. Some of these products are based on combining global satellite-based data and physical formulations, while others come from atmospheric reanalysis and land surface models. The authors found that although there were some differences among the products, the products all captured the seasonality of the heat fluxes as well as the expected spatial distributions related to major climatic regimes and geographical features. Furthermore, the products correlate well with each other in general, in part due to large seasonable variability and the fact that some of the products use the same forcing data. (Journal of Geophysical Research-Atmospheres, doi:10.1029/2010JD014545, 2011)

  17. Potential for Landing Gear Noise Reduction on Advanced Aircraft Configurations

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Nickol, Craig L.; Burley, Casey L.; Guo, Yueping

    2016-01-01

    The potential of significantly reducing aircraft landing gear noise is explored for aircraft configurations with engines installed above the wings or the fuselage. An innovative concept is studied that does not alter the main gear assembly itself but does shorten the main strut and integrates the gear in pods whose interior surfaces are treated with acoustic liner. The concept is meant to achieve maximum noise reduction so that main landing gears can be eliminated as a major source of airframe noise. By applying this concept to an aircraft configuration with 2025 entry-into-service technology levels, it is shown that compared to noise levels of current technology, the main gear noise can be reduced by 10 EPNL dB, bringing the main gear noise close to a floor established by other components such as the nose gear. The assessment of the noise reduction potential accounts for design features for the advanced aircraft configuration and includes the effects of local flow velocity in and around the pods, gear noise reflection from the airframe, and reflection and attenuation from acoustic liner treatment on pod surfaces and doors. A technical roadmap for maturing this concept is discussed, and the possible drag increase at cruise due to the addition of the pods is identified as a challenge, which needs to be quantified and minimized possibly with the combination of detailed design and application of drag reduction technologies.

  18. Intercomparison of land-surface parameterizations launched

    NASA Astrophysics Data System (ADS)

    Henderson-Sellers, A.; Dickinson, R. E.

    One of the crucial tasks for climatic and hydrological scientists over the next several years will be validating land surface process parameterizations used in climate models. There is not, necessarily, a unique set of parameters to be used. Different scientists will want to attempt to capture processes through various methods “for example, Avissar and Verstraete, 1990”. Validation of some aspects of the available (and proposed) schemes' performance is clearly required. It would also be valuable to compare the behavior of the existing schemes [for example, Dickinson et al., 1991; Henderson-Sellers, 1992a].The WMO-CAS Working Group on Numerical Experimentation (WGNE) and the Science Panel of the GEWEX Continental-Scale International Project (GCIP) [for example, Chahine, 1992] have agreed to launch the joint WGNE/GCIP Project for Intercomparison of Land-Surface Parameterization Schemes (PILPS). The principal goal of this project is to achieve greater understanding of the capabilities and potential applications of existing and new land-surface schemes in atmospheric models. It is not anticipated that a single “best” scheme will emerge. Rather, the aim is to explore alternative models in ways compatible with their authors' or exploiters' goals and to increase understanding of the characteristics of these models in the scientific community.

  19. DISAGGREGATION OF GOES LAND SURFACE TEMPERATURES USING SURFACE EMISSIVITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  20. Classification of simulated and actual NOAA-6 AVHRR data for hydrologic land-surface feature definition. [Advanced Very High Resolution Radiometer

    NASA Technical Reports Server (NTRS)

    Ormsby, J. P.

    1982-01-01

    An examination of the possibilities of using Landsat data to simulate NOAA-6 Advanced Very High Resolution Radiometer (AVHRR) data on two channels, as well as using actual NOAA-6 imagery, for large-scale hydrological studies is presented. A running average was obtained of 18 consecutive pixels of 1 km resolution taken by the Landsat scanners were scaled up to 8-bit data and investigated for different gray levels. AVHRR data comprising five channels of 10-bit, band-interleaved information covering 10 deg latitude were analyzed and a suitable pixel grid was chosen for comparison with the Landsat data in a supervised classification format, an unsupervised mode, and with ground truth. Landcover delineation was explored by removing snow, water, and cloud features from the cluster analysis, and resulted in less than 10% difference. Low resolution large-scale data was determined useful for characterizing some landcover features if weekly and/or monthly updates are maintained.

  1. Coupled land surface/hydrologic/atmospheric models

    NASA Technical Reports Server (NTRS)

    Pielke, Roger; Steyaert, Lou; Arritt, Ray; Lahtakia, Mercedes; Smith, Chris; Ziegler, Conrad; Soong, Su Tzai; Avissar, Roni; Wetzel, Peter; Sellers, Piers

    1993-01-01

    The topics covered include the following: prototype land cover characteristics data base for the conterminous United States; surface evapotranspiration effects on cumulus convection and implications for mesoscale models; the use of complex treatment of surface hydrology and thermodynamics within a mesoscale model and some related issues; initialization of soil-water content for regional-scale atmospheric prediction models; impact of surface properties on dryline and MCS evolution; a numerical simulation of heavy precipitation over the complex topography of California; representing mesoscale fluxes induced by landscape discontinuities in global climate models; emphasizing the role of subgrid-scale heterogeneity in surface-air interaction; and problems with modeling and measuring biosphere-atmosphere exchanges of energy, water, and carbon on large scales.

  2. Land Surface Verification Toolkit (LVT) - A Generalized Framework for Land Surface Model Evaluation

    NASA Technical Reports Server (NTRS)

    Kumar, Sujay V.; Peters-Lidard, Christa D.; Santanello, Joseph; Harrison, Ken; Liu, Yuqiong; Shaw, Michael

    2011-01-01

    Model evaluation and verification are key in improving the usage and applicability of simulation models for real-world applications. In this article, the development and capabilities of a formal system for land surface model evaluation called the Land surface Verification Toolkit (LVT) is described. LVT is designed to provide an integrated environment for systematic land model evaluation and facilitates a range of verification approaches and analysis capabilities. LVT operates across multiple temporal and spatial scales and employs a large suite of in-situ, remotely sensed and other model and reanalysis datasets in their native formats. In addition to the traditional accuracy-based measures, LVT also includes uncertainty and ensemble diagnostics, information theory measures, spatial similarity metrics and scale decomposition techniques that provide novel ways for performing diagnostic model evaluations. Though LVT was originally designed to support the land surface modeling and data assimilation framework known as the Land Information System (LIS), it also supports hydrological data products from other, non-LIS environments. In addition, the analysis of diagnostics from various computational subsystems of LIS including data assimilation, optimization and uncertainty estimation are supported within LVT. Together, LIS and LVT provide a robust end-to-end environment for enabling the concepts of model data fusion for hydrological applications. The evolving capabilities of LVT framework are expected to facilitate rapid model evaluation efforts and aid the definition and refinement of formal evaluation procedures for the land surface modeling community.

  3. A blended land emissivity product from the Inter-Comparison of different Land Surface Emissivity Estimates

    NASA Astrophysics Data System (ADS)

    Norouzi, H.; Temimi, M.; Khanbilvardi, R.

    2012-12-01

    Passive microwave observations are routinely used to estimate rain rate, cloud liquid water, and total precipitable water. In order to have accurate estimations from microwave, the contribution of the surface should be accounted for. Over land, due to the complex interaction between the microwave signal and the soil surface, retrieval of land surface emissivity and other surface and subsurface parameters is not straightforward. Several microwave emissivity products from various microwave sensors have been proposed. However, lack of ground truth measurements makes the validation of these products difficult. This study aims to inter-compare several available emissivity products over land and ultimately proposes a unique blended product that overcomes the flaws of each individual product. The selected products are based on observations from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E), the Special Sensor Microwave Imager (SSM/I), the Advanced Microwave Sounding unit (AMSU), and the Special Sensor Microwave Imager/Sounder (SSMIS). In retrieval of emissivities from these sensors different methods and ancillary data have been used. Some inherent discrepancies between the selected products can be introduced by as the difference in geometry in terms of incident angle, spectral response, and the foot print size which can affect the estimations. Moreover, ancillary data especially skin temperature and cloud mask cover can cause significant discrepancies between various estimations. The time series and correlation between emissivity maps are explored to assess the consistency of emissivity variations with geophysical variable such as snow, precipitation and drought. Preliminary results reveal that inconsistency between products varies based on land cover type due to penetration depth effect and ancillary data. Six years of estimations are employed in this research study, and a global blended emissivity estimations based on all product with minimal discrepancies

  4. Timescales of Land Surface Evapotranspiration Response

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  5. Determining Land Surface Temperature Relations with Land Use-Land Cover and Air Pollution

    NASA Astrophysics Data System (ADS)

    Kahya, Ceyhan; Bektas Balcik, Filiz; Burak Oztaner, Yasar; Guney, Burcu

    2016-04-01

    Rapid population growth in conjunction with unplanned urbanization, expansion, and encroachment into the limited agricultural fields and green areas have negative impacts on vegetated areas. Land Surface Temperature (LST), Urban Heat Islands (UHI) and air pollution are the most important environmental problems that the extensive part of the world suffers from. The main objective of this research is to investigate the relationship between LST, air pollution and Land Use-Land Cover (LULC) in Istanbul, using Landsat 8 OLI satellite image. Mono-window algorithm is used to compute LST from Landsat 8 TIR data. In order to determine the air pollution, in-situ measurements of particulate matter (PM10) of the same day as the Landsat 8 OLI satellite image are obtained. The results of this data are interpolated using the Inverse Distance Weighted (IDW) method and LULC categories of Istanbul were determined by using remote sensing indices. Error matrix was created for accuracy assessment. The relationship between LST, air pollution and LULC categories are determined by using regression analysis method. Keywords: Land Surface Temperature (LST), air pollution, Land Use-Land Cover (LULC), Istanbul

  6. Land surface phenology and land surface temperature changes along an urban-rural gradient in Yangtze River Delta, china.

    PubMed

    Han, Guifeng; Xu, Jianhua

    2013-07-01

    Using SPOT/VGT NDVI time series images (2002-2009) and MODIS/LST images (2002-2009) smoothed by a Savitzky-Golay filter, the land surface phenology (LSP) and land surface temperature (LST), respectively, are extracted for six cities in the Yangtze River Delta, China, including Shanghai, Hangzhou, Nanjing, Changzhou, Wuxi, and Suzhou. The trends of the averaged LSP and LST are analyzed, and the relationship between these values is revealed along the urban-rural gradient. The results show that urbanization advances the start of the growing season, postpones the end of the growing season, prolongs the growing season length (GSL), and reduces the difference between maximal NDVI and minimal NDVI in a year (NDVIamp). More obvious changes occur in surface vegetation phenology as the urbanized area is approached. The LST drops monotonously and logarithmically along the urban-rural gradient. Urbanization generally affects the LSP of the surrounding vegetation within 6 km to the urban edge. Except for GSL, the difference in the LSP between urban and rural areas has a significant logarithmic relationship with the distance to the urban edge. In addition, there is a very strong linear relationship between the LSP and the LST along the urban-rural gradient, especially within 6 km to the urban edge. The correlations between LSP and gross domestic product and population density reveal that human activities have considerable influence on the land surface vegetation growth. PMID:23740439

  7. 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.

  8. Advances in Coupling Environmental Models: Land, Atmosphere and Groundwater

    NASA Astrophysics Data System (ADS)

    Peters-Lidard, C. D.; Haitjema, H.; Coats, C. J.; McHenry, J. N.; Trayanov, A.; Pan, F.; Keel, B.

    2001-05-01

    The ability to simulate complex land-atmosphere interactions with high spatial resolution might be required for (i) adequate simulation of certain weakly forced mesoscale episodes, (ii) assimilation of remotely-sensed land surface states; and (iii) detailed simulation of biogeochemical transport processes in multiple media (air, land, and water). We will present results from the application of a novel approach to the coupling of a catchment-scale hydrologically based land surface model (TOPLATS) with a non-hydrostatic mesoscale meteorological model (MM5). The coupled modeling system takes advantage of (i) hydrological similarity, (ii) efficient and parallel communication and I/O, including a NetCDF-based I/O API with PVM extensions, and (iii) sparse-matrix based aggregation and disaggregation techniques to simulate the land-atmosphere system. Application to field sites in Oklahoma and North Carolina shows that by modifying the land surface model and its coupling design to take advantage of similarities in hydrological behavior, the land surface model can be applied with computational performance approaching that of a much simpler model while retaining the complex soil-vegetation-topographical details of the original fully distributed model. One important aspect of this design is that the land surface model retains the notion of the fundamental hydrologic unit-the watershed-and operates on a grid that is independent of the mesoscale model grid. Further, the model communication and I/O design allows for complete flexibility in the coupling configuration, such that coupling might be loose (1-way), intermediate (1.5-way, as in the Land Data Assimilation System project), or full (2-way). The above approach has been recently extended to support coupling of the land surface model with a saturated groundwater flow model. Conceptual issues related to an efficient coupling design for both grid-based and analytic element groundwater models will be discussed.

  9. 25 CFR 226.19 - Use of surface of land.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Use of surface of land. 226.19 Section 226.19 Indians... LANDS FOR OIL AND GAS MINING Operations § 226.19 Use of surface of land. (a) Lessee or his/her authorized representative shall have the right to use so much of the surface of the land within the...

  10. 25 CFR 226.19 - Use of surface of land.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Use of surface of land. 226.19 Section 226.19 Indians... LANDS FOR OIL AND GAS MINING Operations § 226.19 Use of surface of land. (a) Lessee or his/her authorized representative shall have the right to use so much of the surface of the land within the...

  11. 25 CFR 226.19 - Use of surface of land.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Use of surface of land. 226.19 Section 226.19 Indians... LANDS FOR OIL AND GAS MINING Operations § 226.19 Use of surface of land. (a) Lessee or his/her authorized representative shall have the right to use so much of the surface of the land within the...

  12. Toward Transfer Functions for Land Surface Phenologies

    NASA Astrophysics Data System (ADS)

    Henebry, G. M.

    2010-12-01

    A key problem in projecting future landscapes is simulating the associated land surface phenologies (or LSPs). A recent study of land surface models concluded that the representations of crop phenologies among the models diverged sufficiently to impede a useful intercomparison of simulation results from their associated climate models. Grassland phenologies are far more complicated than cropland phenologies due to multiple forcing factors, photosynthetic pathways (C3 vs C4), and spatial heterogeneities in both resource availabilities and land management practices. Furthermore, many tallgrass species (such as switchgrass) are widely distributed across temperature, but not moisture, gradients, resulting in significant ecotypic variation across the species' geographic range. Thus, how feasible is "transplanting" tallgrass LSPs across isotherms—but along isohyets—to simulate a shift in cultivation from maize-soy to switchgrass? Prior work has shown a quadratic model can provide a parsimonious link between a Normalized Difference Vegetation Index (or NDVI) time series and thermal time, measured in terms of accumulated growing degree-days (or AGDD). Moreover, the thermal time to peak NDVI (or TTP) is a simple function of the parameter coefficients of fitted model. I fitted quadratic models to MODIS NDVI and weather station data at multiple sites across the Northern Great Plains over ten growing seasons, 2000-2009. There is a strong latitudinal gradient in TTP that results in part from a quasi-linear gradient in accumulated daylight hours (or ADH) between 30 and 50 degrees north. However, AGDD improves upon ADH by providing sensitivity to the variability of growing season weather. In the quadratic parameter coefficients there is a geographic pattern apparent as a function of TTP, although it is more variable at shorter TTPs. Using these patterns, an LSP transfer function was implemented along a latitudinal transect to simulate switchgrass cultivation in areas now

  13. ENVISAT Land Surface Processes. Phase 2

    NASA Technical Reports Server (NTRS)

    vandenHurk, B. J. J. M.; Su, Z.; Verhoef, W.; Menenti, M.; Li, Z.-L.; Wan, Z.; Moene, A. F.; Roerink, G.; Jia, I.

    2002-01-01

    This is a progress report of the 2nd phase of the project ENVISAT- Land Surface Processes, which has a 3-year scope. In this project, preparative research is carried out aiming at the retrieval of land surface characteristics from the ENVISAT sensors MERIS and AATSR, for assimilation into a system for Numerical Weather Prediction (NWP). Where in the 1st phase a number of first shot experiments were carried out (aiming at gaining experience with the retrievals and data assimilation procedures), the current 2nd phase has put more emphasis on the assessment and improvement of the quality of the retrieved products. The forthcoming phase will be devoted mainly to the data assimilation experiments and the assessment of the added value of the future ENVISAT products for NWP forecast skill. Referring to the retrieval of albedo, leaf area index and atmospheric corrections, preliminary radiative transfer calculations have been carried out that should enable the retrieval of these parameters once AATSR and MERIS data become available. However, much of this work is still to be carried out. An essential part of work in this area is the design and implementation of software that enables an efficient use of MODTRAN(sub 4) radiative transfer code, and during the current project phase familiarization with these new components has been achieved. Significant progress has been made with the retrieval of component temperatures from directional ATSR-images, and the calculation of surface turbulent heat fluxes from these data. The impact of vegetation cover on the retrieved component temperatures appears manageable, and preliminary comparison of foliage temperature to air temperatures were encouraging. The calculation of surface fluxes using the SEBI concept,which includes a detailed model of the surface roughness ratio, appeared to give results that were in reasonable agreement with local measurements with scintillometer devices. The specification of the atmospheric boundary conditions

  14. Session on coupled land surface/hydrological/atmospheric models

    NASA Technical Reports Server (NTRS)

    Pielke, Roger

    1993-01-01

    The current model capabilities in the context of land surface interactions with the atmosphere include only one-dimensional characteristics of vegetation and soil surface heat, moisture, momentum, and selected other trace gas fluxes (e.g., CO2). The influence of spatially coherent fluxes that result from landscape heterogeneity were not included. Valuable representations of several aspects of the landscape pattern currently exist. These include digital elevation data and measures of the leaf area index (i.e., Normalized Difference Vegetation Index (NDVI) from Advanced Very High Resolution Radiometer (AVHRR) data). A major deficiency, however, is the lack of an ability to sample spatially representative shallow and (especially) deep soil moisture. Numerous mesoscale modeling and observed studies demonstrated the sensitivity of planetary boundary layer structure and deep convection to the magnitude of the surface moisture flux.

  15. Earth Observing-1 Advanced Land Imager: Radiometric Response Calibration

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.; Lencioni, D. E.; Evans, J. B.

    2000-01-01

    The Advanced Land Imager (ALI) is one of three instruments to be flown on the first Earth Observing mission (EO-1) under NASA's New Millennium Program (NMP). ALI contains a number of innovative features, including a wide field of view optical design, compact multispectral focal plane arrays, non-cryogenic HgCdTe detectors for the short wave infrared bands, and silicon carbide optics. This document outlines the techniques adopted during ground calibration of the radiometric response of the Advanced Land Imager. Results from system level measurements of the instrument response, signal-to-noise ratio, saturation radiance, and dynamic range for all detectors of every spectral band are also presented.

  16. Multivariate assimilation of satellite-derived land remote sensing datasets: Advances, gaps and challenges

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Peters-Lidard, C. D.; Mocko, D. M.; Jasinski, M. F.; Reichle, R. H.; Zaitchik, B. F.; Getirana, A.; Rodell, M.; Xia, Y.; Ek, M. B.

    2015-12-01

    Remote sensing advancements in recent years have enabled monitoring of the Earth's land surface with unprecedented scale and frequency. In the past decade, remote sensing observations of the land surface have become available from a number of satellite instruments and platforms including soil moisture (AMSR-E, ASCAT, AMSR2, SMOS, SMAP), snow depth (AMSR-E, AMSR2), snow cover (MODIS, VIIRS), terrestrial water storage (GRACE) and land surface temperature (MODIS, VIIRS, GOES). To support the effective exploitation of the information content of the remote sensing observations, computational tools such as data assimilation are necessary. In this presentation, I will describe the efforts towards the concurrent use of all available remote sensing observations in a multivariate data assimilation configuration in the North American Land Data Assimilation System (NLDAS). Though NLDAS has produced over 34 years (Jan 1979 to present) of hourly land-surface meteorology and surface states using the best-available observations and reanalyses for "off-line" land surface model (LSM) simulations, to-date it has not included the assimilation of relevant hydrological remote sensing datasets. The new phase of NLDAS attempts to bridge this gap by assimilating all land relevant datasets in the NLDAS configuration using the NASA Land Information System (LIS). The results from individually assimilating the soil moisture, snow and terrestrial water storage datasets indicate that improvements can be obtained not only in soil moisture and snow states, but also on evapotranspiration and streamflow estimates. The results from the multivariate, multisensor assimilation of the above-mentioned remote sensing datasets in NLDAS and an evaluation of the resulting improvements and trends in soil moisture, snowpack, evapotranspiration and streamflow will also be presented. Through this talk, I will describe the advances made towards the effective utilization of remote sensing data for hydrologic

  17. 25 CFR 214.14 - Use of surface lands.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Use of surface lands. 214.14 Section 214.14 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF OSAGE RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.14 Use of surface lands. (a) Lessees may use...

  18. 25 CFR 214.14 - Use of surface lands.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Use of surface lands. 214.14 Section 214.14 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF OSAGE RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.14 Use of surface lands. (a) Lessees may use...

  19. 25 CFR 214.14 - Use of surface lands.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Use of surface lands. 214.14 Section 214.14 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF OSAGE RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.14 Use of surface lands. (a) Lessees may use so much of...

  20. Advances in Satellite Microwave Precipitation Retrieval Algorithms Over Land

    NASA Astrophysics Data System (ADS)

    Wang, N. Y.; You, Y.; Ferraro, R. R.

    2015-12-01

    Precipitation plays a key role in the earth's climate system, particularly in the aspect of its water and energy balance. Satellite microwave (MW) observations of precipitation provide a viable mean to achieve global measurement of precipitation with sufficient sampling density and accuracy. However, accurate precipitation information over land from satellite MW is a challenging problem. The Goddard Profiling Algorithm (GPROF) algorithm for the Global Precipitation Measurement (GPM) is built around the Bayesian formulation (Evans et al., 1995; Kummerow et al., 1996). GPROF uses the likelihood function and the prior probability distribution function to calculate the expected value of precipitation rate, given the observed brightness temperatures. It is particularly convenient to draw samples from a prior PDF from a predefined database of observations or models. GPROF algorithm does not search all database entries but only the subset thought to correspond to the actual observation. The GPM GPROF V1 database focuses on stratification by surface emissivity class, land surface temperature and total precipitable water. However, there is much uncertainty as to what is the optimal information needed to subset the database for different conditions. To this end, we conduct a database stratification study of using National Mosaic and Multi-Sensor Quantitative Precipitation Estimation, Special Sensor Microwave Imager/Sounder (SSMIS) and Advanced Technology Microwave Sounder (ATMS) and reanalysis data from Modern-Era Retrospective Analysis for Research and Applications (MERRA). Our database study (You et al., 2015) shows that environmental factors such as surface elevation, relative humidity, and storm vertical structure and height, and ice thickness can help in stratifying a single large database to smaller and more homogeneous subsets, in which the surface condition and precipitation vertical profiles are similar. It is found that the probability of detection (POD) increases

  1. 25 CFR 226.19 - Use of surface of land.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... LANDS FOR OIL AND GAS MINING Operations § 226.19 Use of surface of land. (a) Lessee or his/her... originally drilled under the currently lease. A drilling site shall be held to the minimum area essential...

  2. 25 CFR 226.19 - Use of surface of land.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... LANDS FOR OIL AND GAS MINING Operations § 226.19 Use of surface of land. (a) Lessee or his/her... originally drilled under the currently lease. A drilling site shall be held to the minimum area essential...

  3. Aggregation effects of surface heterogeneity in land surface processes

    NASA Astrophysics Data System (ADS)

    Su, Z.; Pelgrum, H.; Menenti, M.

    In order to investigate the aggregation effects of surface heterogeneity in land surface processes we have adapted a theory of aggregation. Two strategies have been adopted: 1) Aggregation of radiative fluxes. The aggregated radiative fluxes are used to derive input parameters that are then used to calculate the aerodynamic fluxes at different aggregation levels. This is equivalent to observing the same area at different resolutions using a certain remote sensor, and then calculating the aerodynamic fluxes correspondingly. 2) Aggregation of aerodynamic fluxes calculated at the original observation scale to different aggregation levels. A case study has been conducted to identify the effects of aggregation on areal estimates of sensible and latent heat fluxes. The length scales of surface variables in heterogeneous landscapes are estimated by means of wavelet analysis.

  4. Mapping the global land surface using 1 km AVHRR data

    USGS Publications Warehouse

    Lauer, D.T.; Eidenshink, J.C.

    1998-01-01

    The scientific requirements for mapping the global land surface using 1 km advanced very high resolution radiometer (AVHRR) data have been set forth by the U.S. Global Change Research Program; the International Geosphere Biosphere Programme (IGBP); The United Nations; the National Oceanic and Atmospheric Administration (NOAA); the Committee on Earth Observations Satellites; and the National Aeronautics and Space Administration (NASA) mission to planet Earth (MTPE) program. Mapping the global land surface using 1 km AVHRR data is an international effort to acquire, archive, process, and distribute 1 km AVHRR data to meet the needs of the international science community. A network of AVHRR receiving stations, along with data recorded by NOAA, has been acquiring daily global land coverage since April 1, 1992. A data set of over 70,000 AVHRR images is archived and distributed by the United States Geological Survey (USGS) EROS Data Center, and the European Space Agency. Under the guidance of the IGBP, processing standards have been developed for calibration, atmospheric correction, geometric registration, and the production of global 10-day maximum normalized difference vegetation index (NDVI) composites. The major uses of the composites are for the study of surface vegetation condition, mapping land cover, and deriving biophysical characteristics of terrestrial ecosystems. A time-series of 54 10-day global vegetation index composites for the period of April 1, 1992 through September 1993 has been produced. The production of a time-series of 33 10-day global vegetation index composites using NOAA-14 data for the period of February 1, 1995 through December 31, 1995 is underway. The data products are available from the USGS, in cooperation with NASA's MTPE program and other international organizations.

  5. 40 CFR 35.2260 - Advance purchase of eligible land.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Advance purchase of eligible land. 35.2260 Section 35.2260 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... building of facilities: §§ 35.2105, 35.2130, 35.2140, 35.2206 and 35.2208....

  6. 40 CFR 35.2260 - Advance purchase of eligible land.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Advance purchase of eligible land. 35.2260 Section 35.2260 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... building of facilities: §§ 35.2105, 35.2130, 35.2140, 35.2206 and 35.2208....

  7. 40 CFR 35.2260 - Advance purchase of eligible land.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Advance purchase of eligible land. 35.2260 Section 35.2260 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... building of facilities: §§ 35.2105, 35.2130, 35.2140, 35.2206 and 35.2208....

  8. Cities and Urban Land Use in Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Ford, Larry R.

    2000-01-01

    Discusses the cities and urban land use section of the Advanced Placement (AP) human geography course, focusing on the: (1) definitions of urbanism; (2) origin and evolution of cities; (3) functional character of contemporary cities; (4) built environment and social space; and (5) responses to urban growth. (CMK)

  9. Regional Land Surface Hydrology Impacts from Fire-Induced Surface Albedo Darkening in Northern Sub-Saharan Africa

    NASA Astrophysics Data System (ADS)

    Bolten, J. D.; Gupta, M.; Gatebe, C. K.; Ichoku, C. M.

    2015-12-01

    Land surface hydrology models serve as an effective approach to simulate hydrological processes, especially in areas which lack in situ observational datasets. A key component to constraining the water, energy, and carbon dynamics within these models is land surface albedo because it links these cycles by driving evapotranspiration and also helps characterize soil infiltration behavior. However, most hydrological models estimate the land surface albedo based on generalized climatologic information, which can introduce uncertainty into the surface energy balance processes and water storage availability in the root-zone if done improperly. In particular, changes in surface albedo can have significant effects where dynamic and spatially heterogeneous land surface changes occur due to abrupt land cover changes, such as wildfire. Sub-Saharan Africa is one of the most fire-prone regions of the world. Thus, the current study employs the new parameterization approach based on estimated change of surface albedo due to fires over different land cover types using long term MODIS time series in the catchment-based land surface model to investigate the potential for improving soil moisture and evapotranspiration simulations in fire-prone Northern Sub-Saharan Africa. We also compare the estimated soil moisture based on new and pre-existing baseline parameterization scheme to remotely-sensed observations obtained from satellite-based soil moisture observations from the Advanced Microwave Scanning Radiometer (AMSR-E), the Soil Moisture Ocean Salinity (SMOS), and the recently launched satellite, Soil Moisture Active Passive (SMAP) instruments.

  10. Landscape pattern change analyses of land surface radiation during the city expansion in Jinan City

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaoyan; Gao, Zhiqiang

    2007-09-01

    The issues of urbanization and Land Use / Cover Change (LUCC) are both hot topics in the global change research which are now bound by human survival and development. This article takes the Shandong Jinan City as case study, and analyzing the impact of LUCC on land surface temperature and radiation during the urbanization advancement. This paper uses two periods of multi-temporal Landsat TM/ETM image data, and combining plenty of resources and choosing feasible classification system, and integrating remote sensing and geographic information systems (GIS) for detecting land cover change. We obtain the Land Use / Cover (LUC) maps of Jinan by visual interpretation and the LUC transfer matrix through GIS technique. And then we analyze the causes of LUCC. Retrieve out the land surface temperature and the land surface radiation by using single Landsat TM/ETM 6 thermal infrared data and weather data. We obtain the surface temperature and radiation distribution maps. Considering the transform of LUC, we analyze their impacts on land surface temperature and radiation in the region. Analyzing and describing the space pattern and time change of the impacts of land use and urbanization on land surface temperature and radiation during the past 6 years in Jinan. And provide a foundation to the researches of urbanization process mechanism and environment protection.

  11. The Effect of Land Use Change on Land Surface Temperature in the Netherlands

    NASA Astrophysics Data System (ADS)

    Youneszadeh, S.; Amiri, N.; Pilesjo, P.

    2015-12-01

    The Netherlands is a small country with a relatively large population which experienced a rapid rate of land use changes from 2000 to 2008 years due to the industrialization and population increase. Land use change is especially related to the urban expansion and open agriculture reduction due to the enhanced economic growth. This research reports an investigation into the application of remote sensing and geographical information system (GIS) in combination with statistical methods to provide a quantitative information on the effect of land use change on the land surface temperature. In this study, remote sensing techniques were used to retrieve the land surface temperature (LST) by using the MODIS Terra (MOD11A2) Satellite imagery product. As land use change alters the thermal environment, the land surface temperature (LST) could be a proper change indicator to show the thermal changes in relation with land use changes. The Geographical information system was further applied to extract the mean yearly land surface temperature (LST) for each land use type and each province in the 2003, 2006 and 2008 years, by using the zonal statistic techniques. The results show that, the inland water and offshore area has the highest night land surface temperature (LST). Furthermore, the Zued (South)-Holland province has the highest night LST value in the 2003, 2006 and 2008 years. The result of this research will be helpful tool for urban planners and environmental scientists by providing the critical information about the land surface temperature.

  12. Estimation of Land Surface States and Fluxes using a Land Surface Model Considering Different Irrigation Systems

    NASA Astrophysics Data System (ADS)

    Chun, J. A.; Zaitchik, B. F.; Evans, J. P.; Beaudoing, H. K.

    2012-12-01

    Food security can be improved by increasing the extent of agricultural land or by increasing agricultural productivity, including through intensive management such as irrigation. The objectives of this study were to incorporate practical irrigation schemes into land surface models of the NASA Land Information System (LIS) and to apply the tool to estimate the impact of irrigation on land surface states and fluxes—including evapotranspiration, soil moisture, and runoff—in the Murray-Darling basin in Australia. Here we present results obtained using Noah Land Surface Model v3.2 within LIS without simulated irrigation (IR0) and with three irrigation simulation routines: flood irrigation (IR1), drip irrigation (IR2), and sprinkler irrigation (IR3). Moderate Resolution Imaging Spectrometer (MODIS) vegetation index was used to define crop growing seasons. Simulations were performed for a full year (July 2002 to June 2003) and evaluated against hydrologic flux estimates obtained in previous studies. Irrigation amounts during the growing season (August 2002 to March 2003) were simulated as 104.6, 24.6, and 188.1 GL for IR1, IR2, and IR3, respectively. These preliminary results showed water use efficiency from a drip irrigation scheme would be highest and lowest from a sprinkler irrigation scheme, with a highly optimized version of flood irrigation falling in between. Irrigation water contributed to a combination of increased evapotranspiration, runoff, and soil moisture storage in the irrigation simulations relative to IR0. Implications for water management applications and for further model development will be discussed.

  13. Quantifying Uncertainties in Land-Surface Microwave Emissivity Retrievals

    NASA Technical Reports Server (NTRS)

    Tian, Yudong; Peters-Lidard, Christa D.; Harrison, Kenneth W.; Prigent, Catherine; Norouzi, Hamidreza; Aires, Filipe; Boukabara, Sid-Ahmed; Furuzawa, Fumie A.; Masunaga, Hirohiko

    2013-01-01

    Uncertainties in the retrievals of microwaveland-surface emissivities are quantified over two types of land surfaces: desert and tropical rainforest. Retrievals from satellite-based microwave imagers, including the Special Sensor Microwave Imager, the Tropical Rainfall Measuring Mission Microwave Imager, and the Advanced Microwave Scanning Radiometer for Earth Observing System, are studied. Our results show that there are considerable differences between the retrievals from different sensors and from different groups over these two land-surface types. In addition, the mean emissivity values show different spectral behavior across the frequencies. With the true emissivity assumed largely constant over both of the two sites throughout the study period, the differences are largely attributed to the systematic and random errors inthe retrievals. Generally, these retrievals tend to agree better at lower frequencies than at higher ones, with systematic differences ranging 1%-4% (3-12 K) over desert and 1%-7% (3-20 K) over rainforest. The random errors within each retrieval dataset are in the range of 0.5%-2% (2-6 K). In particular, at 85.5/89.0 GHz, there are very large differences between the different retrieval datasets, and within each retrieval dataset itself. Further investigation reveals that these differences are most likely caused by rain/cloud contamination, which can lead to random errors up to 10-17 K under the most severe conditions.

  14. Enhancing the Representation of Subgrid Land Surface Characteristics in Land Surface Models

    SciTech Connect

    Ke, Yinghai; Leung, Lai-Yung R.; Huang, Maoyi; Li, Hongyi

    2013-09-27

    Land surface heterogeneity has long been recognized and increasingly incorporated in the land surface modelling. In most existing land surface models, the spatial variability of surface cover is represented as subgrid composition of multiple surface cover types. In this study, we developed a new subgrid classification method (SGC) that accounts for the topographic variability of the vegetation cover. Each model grid cell was represented with a number of elevation classes and each elevation class was further described by a number of vegetation types. The numbers of elevation classes and vegetation types were variable and optimized for each model grid so that the spatial variability of both elevation and vegetation can be reasonably explained given a pre-determined total number of classes. The subgrid structure of the Community Land Model (CLM) was used as an example to illustrate the newly developed method in this study. With similar computational burden as the current subgrid vegetation representation in CLM, the new method is able to explain at least 80% of the total subgrid PFTs and greatly reduced the variations of elevation within each subgrid class compared to the baseline method where a single elevation class is assigned to each subgrid PFT. The new method was also evaluated against two other subgrid methods (SGC1 and SGC2) that assigned fixed numbers of elevation and vegetation classes for each model grid with different perspectives of surface cover classification. Implemented at five model resolutions (0.1°, 0.25°, 0.5°, 1.0° and 2.0°) with three maximum-allowed total number of classes N_class of 24, 18 and 12 representing different computational burdens over the North America (NA) continent, the new method showed variable performances compared to the SGC1 and SGC2 methods. However, the advantage of the SGC method over the other two methods clearly emerged at coarser model resolutions and with moderate computational intensity (N_class = 18) as it

  15. Hydrologic Remote Sensing and Land Surface Data Assimilation

    PubMed Central

    Moradkhani, Hamid

    2008-01-01

    Accurate, reliable and skillful forecasting of key environmental variables such as soil moisture and snow are of paramount importance due to their strong influence on many water resources applications including flood control, agricultural production and effective water resources management which collectively control the behavior of the climate system. Soil moisture is a key state variable in land surface–atmosphere interactions affecting surface energy fluxes, runoff and the radiation balance. Snow processes also have a large influence on land-atmosphere energy exchanges due to snow high albedo, low thermal conductivity and considerable spatial and temporal variability resulting in the dramatic change on surface and ground temperature. Measurement of these two variables is possible through variety of methods using ground-based and remote sensing procedures. Remote sensing, however, holds great promise for soil moisture and snow measurements which have considerable spatial and temporal variability. Merging these measurements with hydrologic model outputs in a systematic and effective way results in an improvement of land surface model prediction. Data Assimilation provides a mechanism to combine these two sources of estimation. Much success has been attained in recent years in using data from passive microwave sensors and assimilating them into the models. This paper provides an overview of the remote sensing measurement techniques for soil moisture and snow data and describes the advances in data assimilation techniques through the ensemble filtering, mainly Ensemble Kalman filter (EnKF) and Particle filter (PF), for improving the model prediction and reducing the uncertainties involved in prediction process. It is believed that PF provides a complete representation of the probability distribution of state variables of interests (according to sequential Bayes law) and could be a strong alternative to EnKF which is subject to some limitations including the linear

  16. Stochastic repercussion of land-surface energy budget noise onto a coupled land-atmosphere model

    NASA Astrophysics Data System (ADS)

    Gentine, P.; Entekhabi, D.; Schertzer, E.; Polcher, J.

    2009-04-01

    The present study is based on the work first introduced by Lettau (1951): in this paper Lettau analytically studied the response of a linearized land-atmosphere model to a sinusoidal forcing of net radiation at the land-surface. The model has been first improved to obtain the analytical solution of the temperature and heat flux profiles in the soil and in the Atmospheric Boundary Layer (ABL) in response to any daily forcing of incoming radiation at the land-surface. With this model, the profiles of temperature and heat are expressed in terms of temporal Fourier series. Moreover the surface variables (temperature, specific humidity, surface fluxes) are also derived analytically and their diurnal course is expressed as a function of both surface parameters (friction velocity, vegetation height, aerodynamic resistance, stomatal conductance). In this presentation, we further extend the application of this theoretical model to the study of the error in the land-surface energy budget closure. This closure error could result form either modeling or experimental inaccuracies, leading to incorrect energy partitioning at the land-surface. In particular, the response of the coupled land-atmosphere model to the land-surface energy error is investigated. This noise in the energy budget is introduced in the form of a stochastic Brownian Bridge, which is a Brownian Motion conditioned to vanish at 0h and 24h. First the impact of land-surface noise on the partitioning of land-surface energy partitioning is examined. Moreover the influence of the land-surface noise on Land Surface Temperature and air temperature is carefully analyzed, as it is fundamental for the use of data assimilation in conjunction with land-surface models. Finally, the repercussion of the surface noise in the ABL and the soil is analytically found and its temporal and spatial dependency is studied. In particular, the correlation between the land-surface state and the ABL state is further investigated. These

  17. Surface Hydrology in Global River Basins in the Off-Line Land-Surface GEOS Assimilation (OLGA) System

    NASA Technical Reports Server (NTRS)

    Bosilovich, Michael G.; Yang, Runhua; Houser, Paul R.

    1998-01-01

    Land surface hydrology for the Off-line Land-surface GEOS Analysis (OLGA) system and Goddard Earth Observing System (GEOS-1) Data Assimilation System (DAS) has been examined using a river routing model. The GEOS-1 DAS land-surface parameterization is very simple, using an energy balance prediction of surface temperature and prescribed soil water. OLGA uses near-surface atmospheric data from the GEOS-1 DAS to drive a more comprehensive parameterization of the land-surface physics. The two global systems are evaluated using a global river routing model. The river routing model uses climatologic surface runoff from each system to simulate the river discharge from global river basins, which can be compared to climatologic river discharge. Due to the soil hydrology, the OLGA system shows a general improvement in the simulation of river discharge compared to the GEOS-1 DAS. Snowmelt processes included in OLGA also have a positive effect on the annual cycle of river discharge and source runoff. Preliminary tests of a coupled land-atmosphere model indicate improvements to the hydrologic cycle compared to the uncoupled system. The river routing model has provided a useful tool in the evaluation of the GCM hydrologic cycle, and has helped quantify the influence of the more advanced land surface model.

  18. 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

  19. NASA Lands Car-sized Rover on Martian Surface

    NASA Video Gallery

    NASA's most advanced Mars rover Curiosity has landed on the Red Planet. The one-ton rover, hanging by ropes from a rocket backpack, touched down onto Mars Sunday to end a 36-week flight and begin a...

  20. CARBON SEQUESTRATION ON SURFACE MINE LANDS

    SciTech Connect

    Donald H. Graves; Christopher Barton; Richard Sweigard; Richard Warner

    2003-10-30

    The 2002-2003 Department of Energy plantings amounted to 164 acres containing 111,520 tree seedlings in eastern and western Kentucky. Data gathered on these trees included an inventory to determine survival of all planted species. A sub-sample of seedlings was selected to assess the height and diameter of individual species of seedlings established. Additional efforts involved collection of soil sample and litter samples, analysis of herbaceous ground cover from vegetation clip plots and leaf area on each tree species, and development of tissue collections. All areas were sampled for penetration resistance, penetration depth (or depth to refusal), and bulk density at various depths. Rain fall events and flow rates were recorded. The water quality of runoff samples involved the determination of total and settleable solids and particle size distribution. A study was initiated that will focus on the colonization of small mammals from forest edges to various areas located on reclaimed surface mines. This effort will provide a better understanding of the role small mammals and birds have in the establishment of plant communities on mine lands that will be useful in developing and improving reclamation techniques.

  1. Ground surface temperature simulation for different land covers

    NASA Astrophysics Data System (ADS)

    Herb, William R.; Janke, Ben; Mohseni, Omid; Stefan, Heinz G.

    2008-07-01

    SummaryA model for predicting temperature time series for dry and wet land surfaces is described, as part of a larger project to assess the impact of urban development on the temperature of surface runoff and coldwater streams. Surface heat transfer processes on impervious and pervious land surfaces were investigated for both dry and wet weather periods. The surface heat transfer equations were combined with a numerical approximation of the 1-D unsteady heat diffusion equation to calculate pavement and soil temperature profiles to a depth of 10 m. Equations to predict the magnitude of the radiative, convective, conductive and evaporative heat fluxes at a dry or wet surface, using standard climate data as input, were developed. A model for the effect of plant canopies on surface heat transfer was included for vegetated land surfaces. Given suitable climate data, the model can simulate the land surface and sub-surface temperatures continuously throughout a six month time period or for a single rainfall event. Land surface temperatures have been successfully simulated for pavements, bare soil, short and tall grass, a forest, and two agricultural crops (corn and soybeans). The simulations were run for three different locations in US, and different years as imposed by the availability of measured soil temperature and climate data. To clarify the effect of land use on surface temperatures, the calibrated coefficients for each land use and the same soil coefficients were used to simulate surface temperatures for a six year climate data set from Albertville, MN. Asphalt and concrete give the highest surface temperatures, as expected, while vegetated surfaces gave the lowest. Bare soil gives surface temperatures that lie between those for pavements and plant-covered surfaces. The soil temperature model predicts hourly surface temperatures of bare soil and pavement with root-mean-square errors (RMSEs) of 1-2 °C, and hourly surface temperatures of vegetation-covered surfaces

  2. Climate and the equilibrium state of land surface hydrology parameterizations

    NASA Technical Reports Server (NTRS)

    Entekhabi, Dara; Eagleson, Peter S.

    1991-01-01

    For given climatic rates of precipitation and potential evaporation, the land surface hydrology parameterizations of atmospheric general circulation models will maintain soil-water storage conditions that balance the moisture input and output. The surface relative soil saturation for such climatic conditions serves as a measure of the land surface parameterization state under a given forcing. The equilibrium value of this variable for alternate parameterizations of land surface hydrology are determined as a function of climate and the sensitivity of the surface to shifts and changes in climatic forcing are estimated.

  3. A NEW LAND-SURFACE MODEL IN MM5

    EPA Science Inventory

    There has recently been a general realization that more sophisticated modeling of land-surface processes can be important for mesoscale meteorology models. Land-surface models (LSMs) have long been important components in global-scale climate models because of their more compl...

  4. 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.

  5. Surface Characterization for Land-Atmosphere Studies of CLASIC

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Cloud and Land Surface Interaction Campaign will focus on interactions between the land surface, convective boundary layer, and cumulus clouds. It will take place in the Southern Great Plains (SGP) area of the U.S, specifically within the US DOE ARM Climate Research Facility. The intensive obser...

  6. Carbon Sequestration on Surface Mine Lands

    SciTech Connect

    Donald Graves; Christopher Barton; Richard Sweigard; Richard Warner; Carmen Agouridis

    2006-03-31

    Since the implementation of the federal Surface Mining Control and Reclamation Act of 1977 (SMCRA) in May of 1978, many opportunities have been lost for the reforestation of surface mines in the eastern United States. Research has shown that excessive compaction of spoil material in the backfilling and grading process is the biggest impediment to the establishment of productive forests as a post-mining land use (Ashby, 1998, Burger et al., 1994, Graves et al., 2000). Stability of mine sites was a prominent concern among regulators and mine operators in the years immediately following the implementation of SMCRA. These concerns resulted in the highly compacted, flatly graded, and consequently unproductive spoils of the early post-SMCRA era. However, there is nothing in the regulations that requires mine sites to be overly compacted as long as stability is achieved. It has been cultural barriers and not regulatory barriers that have contributed to the failure of reforestation efforts under the federal law over the past 27 years. Efforts to change the perception that the federal law and regulations impede effective reforestation techniques and interfere with bond release must be implemented. Demonstration of techniques that lead to the successful reforestation of surface mines is one such method that can be used to change perceptions and protect the forest ecosystems that were indigenous to these areas prior to mining. The University of Kentucky initiated a large-scale reforestation effort to address regulatory and cultural impediments to forest reclamation in 2003. During the three years of this project 383,000 trees were planted on over 556 acres in different physiographic areas of Kentucky (Table 1, Figure 1). Species used for the project were similar to those that existed on the sites before mining was initiated (Table 2). A monitoring program was undertaken to evaluate growth and survival of the planted species as a function of spoil characteristics and

  7. How Water Advances on Superhydrophobic Surfaces

    NASA Astrophysics Data System (ADS)

    Schellenberger, Frank; Encinas, Noemí; Vollmer, Doris; Butt, Hans-Jürgen

    2016-03-01

    Superliquid repellency can be achieved by nano- and microstructuring surfaces in such a way that protrusions entrap air underneath the liquid. It is still not known how the three-phase contact line advances on such structured surfaces. In contrast to a smooth surface, where the contact line can advance continuously, on a superliquid-repellent surface, the contact line has to overcome an air gap between protrusions. Here, we apply laser scanning confocal microscopy to get the first microscopic videos of water drops advancing on a superhydrophobic array of micropillars. In contrast to common belief, the liquid surface gradually bends down until it touches the top face of the next micropillars. The apparent advancing contact angle is 180°. On the receding side, pinning to the top faces of the micropillars determines the apparent receding contact angle. Based on these observations, we propose that the apparent receding contact angle should be used for characterizing superliquid-repellent surfaces rather than the apparent advancing contact angle and hysteresis.

  8. Development of high resolution land surface parameters for the Community Land Model

    NASA Astrophysics Data System (ADS)

    Ke, Y.; Leung, L. R.; Huang, M.; Coleman, A. M.; Li, H.; Wigmosta, M. S.

    2012-06-01

    There is a growing need for high-resolution land surface parameters as land surface models are being applied at increasingly higher spatial resolution offline as well as in regional and global models. The default land surface parameters for the most recent version of the Community Land Model (i.e. CLM 4.0) are at 0.5° or coarser resolutions, released with the model from the National Center for Atmospheric Research (NCAR). Plant Functional Types (PFTs), vegetation properties such as Leaf Area Index (LAI), Stem Area Index (SAI), and non-vegetated land covers were developed using remotely-sensed datasets retrieved in late 1990's and the beginning of this century. In this study, we developed new land surface parameters for CLM 4.0, specifically PFTs, LAI, SAI and non-vegetated land cover composition, at 0.05° resolution globally based on the most recent MODIS land cover and improved MODIS LAI products. Compared to the current CLM 4.0 parameters, the new parameters produced a decreased coverage by bare soil and trees, but an increased coverage by shrub, grass, and cropland. The new parameters result in a decrease in global seasonal LAI, with the biggest decrease in boreal forests; however, the new parameters also show a large increase in LAI in tropical forest. Differences between the new and the current parameters are mainly caused by changes in the sources of remotely sensed data and the representation of land cover in the source data. The new high-resolution land surface parameters have been used in a coupled land-atmosphere model (WRF-CLM) applied to the western US to demonstrate their use in high-resolution modeling. Future work will include global offline CLMsimulations to examine the impacts of source data resolution and subsequent land parameter changes on simulated land surface processes.

  9. Development of practical multiband algorithms for estimating land-surface temperature from EOS/MODIS data

    NASA Technical Reports Server (NTRS)

    Dozier, J.; Wan, Z.

    1994-01-01

    A practical multiband, hierarchical algorithm for estimating land-surface temperature from NASA's future Earth Observing System (EOS) instruments Moderate Resolution Imaging Spectroradiometer (MODIS) and Advance Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is developed through comprehensive, accurate, radiative transfer simulations at moderate spectral steps of 1-5/cm for wide ranges of atmospheric and surface conditions. The algorithm will accept empirical or estimated information about the surface emissivity and reflectivity and the atmospheric temperature and water-vapor profiles. Ground-based and aircraft measurements are necessary to validate and improve the algorithm and to establish its quality. Its accuracy depends on the calibration accuracy of thermal infrared data, uncertainties in surface heterogeneity, and temperature-dependent atmospheric absorption coefficients. Better knowledge of land-surface spectral emissivities and more accurate coefficients for atmospheric molecular band absorption and water vapor continuum absorption are needed to develop global land-surface temperature algorithms accurate to 1-2 K.

  10. Vancouver 2010 Winter Olympics Land Surface Forecast System

    NASA Astrophysics Data System (ADS)

    Bernier, N. B.; Belair, S.; Tong, L.; Abrahamowicz, M.; Mailhot, J.

    2009-04-01

    Environment Canada's land surface forecast system developed for the Vancouver 2010 Winter Olympics is presented together with an evaluation of its performance for winters 2007-2008 and 2008-2009. The motivation for this work is threefold: it is i) application driven for the 2010 Vancouver Olympics, ii) a testbed for the panCanadian operational land surface forecast model being developed, and iii) the precursor to the fully coupled land-surface model to come. The new high resolution (100m grid size), 2D, and novel imbedded point-based land surface forecast model used to predict hourly snow and surface temperature conditions at Olympic and Paralympic Competition Sites are described. The surface systems are driven by atmospheric forcing provided by the center's operational regional forecast model for the first 48 hours and by the operational global forecast model for hours 49 to 96. The forcing fields are corrected for elevation discrepancies over the rapidly changing and complex mountainous settings of the Vancouver Olympics that arise from resolution differences. Daily 96h land surface forecasts for 2 winters and snow depth and surface air temperature observations collected at several specially deployed competition sites are used to validate the land surface model. We show that the newly implemented surface forecast model refines and improves snow depth and surface temperature forecast issued by the operational weather forecast system throughout the forecast period.

  11. Human Mars Landing Site and Impacts on Mars Surface Operations

    NASA Technical Reports Server (NTRS)

    Bussey, Ben; Hoffman, Stephen J.

    2016-01-01

    NASA has begun a process to identify and discuss candidate locations where humans could land, live and work on the Martian surface. These locations are referred to as Exploration Zones (EZs). Given current mission concepts, an EZ is a collection of Regions of Interest (ROIs) that are located within approximately 100 kilometers of a centralized landing site. ROIs are areas that are relevant for scientific investigation and/or development/maturation of capabilities and resources necessary for a sustainable human presence. The EZ also contains a landing site and a habitation site that will be used by multiple human crews during missions to explore and utilize the ROIs within the EZ. These candidate EZs will be used by NASA as part of a multi-year process of determining where and how humans could explore Mars. In the near term this process includes: (a) identifying locations that would maximize the potential science return from future human exploration missions, (b) identifying locations with the potential for resources required to support humans, (c) developing concepts and engineering systems needed by future human crews to conduct operations within an EZ, and (d) identifying key characteristics of the proposed candidate EZs that cannot be evaluated using existing data sets, thus helping to define precursor measurements needed in advance of human missions. Existing and future robotic spacecraft will be tasked to gather data from specific Mars surface sites within the representative EZs to support these NASA activities. The proposed paper will describe NASA's initial steps for identifying and evaluating candidate EZs and ROIs. This includes plans for the "First Landing Site/Exploration Zone Workshop for Human Missions to the Surface of Mars" to be held in October 2015 at which proposals for EZs and ROIs will be presented and discussed. It will also include a discussion of how these considerations are (or will be) taken into account as future robotic Mars missions are

  12. 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.

  13. Classes of land-surface form in the United States

    USGS Publications Warehouse

    Hammond, Edwin

    1964-01-01

    This digital dataset describes classes of land-surface form in the conterminous United States. The source of the data is the map of land-surface form in the 1970 National Atlas of the United States, pages 62-63, which was adapted from Edwin H. Hammond, "Classes of land surface form in the forty-eight states, U.S.A," Annals of the Assoc. of Am. Geographers, v.54, no. 1, 1964, map supp. no. 1, 1:5,000,000.

  14. Improving arable land heterogeneity information in available land cover products for land surface modelling using MERIS NDVI data

    NASA Astrophysics Data System (ADS)

    Zabel, F.; Hank, T. B.; Mauser, W.

    2010-07-01

    Regionalization of physical land surface models requires the supply of detailed land cover information. Numerous global and regional land cover maps already exist, but generally they do not resolve arable land into different crop types. However, the characteristic phenological behaviour of different crops affects the mass and energy fluxes on the land surface and thus its hydrology. The objective of this study is the generation of a land cover map for Central Europe based on CORINE Land Cover 2000, merged with CORINE Switzerland, but distinguishing different crop types. Accordingly, an approach was developed, subdividing the land cover class arable land into the regionally most relevant subclasses for Central Europe using statistical data from EUROSTAT. This database was analysed concerning the acreage of different crop types, taking a multiseasonal series of MERIS Normalized Difference Vegetation Index (NDVI) into account. The satellite data were used for the separation of spring and summer crops. The hydrological impact of the improved land cover map was modelled exemplarily for the Upper Danube catchment.

  15. Estimation of Surface Air Temperature from MODIS 1km Resolution Land Surface Temperature Over Northern China

    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).

  16. Mapping global land surface albedo from NOAA AVHRR

    NASA Astrophysics Data System (ADS)

    Csiszar, I.; Gutman, G.

    1999-03-01

    A set of algorithms is combined for a simple derivation of land surface albedo from measurements of reflected visible and near-infrared radiation made by the advanced very high resolution radiometer (AVHRR) onboard the National Oceanic and Atmospheric Administration (NOAA) polar orbiting satellites. The system consists of a narrowband-to-broadband conversion and bidirectional correction at the top of the atmosphere and an atmospheric correction. We demonstrate the results with 1 month worth of data from the NOAA National Environmental Satellite, Data, and Information Service (NESDIS) global vegetation index (GVI) weekly data set and the NOAA/NASA Pathfinder Atmosphere (PATMOS) project daily data. Error analysis of the methodology indicates that the surface albedo can be retrieved with 10-15% relative accuracy. Monthly albedo maps derived from September 1989 GVI and PATMOS data agree well except for small discrepancies attributed mainly to different preprocessing and residual atmospheric effects. A 5-year mean September map derived from the GVI multiannual time series is consistent with that derived from low-resolution Earth Radiation Budget Experiment data as well as with a September map compiled from ground observations and used in many numerical weather and climate models. Instantaneous GVI-derived albedos were found to be consistent with surface albedo measurements over various surface types. The discrepancies found can be attributed to differences in areal coverage and representativeness of the satellite and ground data. The present pilot study is a prototype for a routine real-time production of high-resolution global surface albedo maps from NOAA AVHRR Global Area Coverage (GAC) data.

  17. Improving arable land heterogeneity information in available land cover products for land surface modelling using MERIS NDVI data

    NASA Astrophysics Data System (ADS)

    Zabel, F.; Hank, T. B.; Mauser, W.

    2010-10-01

    Regionalization of physical land surface models requires the supply of detailed land cover information. Numerous global and regional land cover maps already exist but generally, they do not resolve arable land into different crop types. However, arable land comprises a huge variety of different crops with characteristic phenological behaviour, demonstrated in this paper with Leaf Area Index (LAI) measurements exemplarily for maize and winter wheat. This affects the mass and energy fluxes on the land surface and thus its hydrology. The objective of this study is the generation of a land cover map for central Europe based on CORINE Land Cover (CLC) 2000, merged with CORINE Switzerland, but distinguishing different crop types. Accordingly, an approach was developed, subdividing the land cover class arable land into the regionally most relevant subclasses for central Europe using multiseasonal MERIS Normalized Difference Vegetation Index (NDVI) data. The satellite data were used for the separation of spring and summer crops due to their different phenological behaviour. Subsequently, the generated phenological classes were subdivided following statistical data from EUROSTAT. This database was analysed concerning the acreage of different crop types. The impact of the improved land use/cover map on evapotranspiration was modelled exemplarily for the Upper Danube catchment with the hydrological model PROMET. Simulations based on the newly developed land cover approach showed a more detailed evapotranspiration pattern compared to model results using the traditional CLC map, which is ignorant of most arable subdivisions. Due to the improved temporal behaviour and spatial allocation of evapotranspiration processes in the new land cover approach, the simulated water balance more closely matches the measured gauge.

  18. MEaSUREs Land Surface Temperature from GOES satellites

    NASA Astrophysics Data System (ADS)

    Pinker, Rachel T.; Ma, Yingtao; Chen, Wen; Hulley, Glynn; Borbas, Eva; Hain, Chris; Hook, Simon

    2016-04-01

    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. Both observations have unique advantages, however, when combined, introduced are challenges related to inhomogeneity of the resulting information. NASA has identified a major need for developing long-term, consistent, and calibrated data and products that are consistent across multiple missions and satellite sensors. Under a project titled: "A Unified and Coherent Land Surface Temperature and Emissivity Earth System Data Record (ESDR) for Earth Science" led by Jet Propulsion Laboratory, such an effort is underway. In this presentation we will describe part of that effort, dealing with the generation of an approach to derive LST information from the GOES satellites from 2000 and onward. Since implementation of the well-established split window approach is not possible after mid-2003 (will be possible again after the launch of GOES-R in October of 2016), there is a need to focus on retrievals from a single thermal channel in order to provide continuity in the LST record. The methodology development requires the generation of consistently calibrated GOES observations, identification of clear sky radiances, and development of retrieval algorithms that benefit from most recent advances in related fields that provide auxiliary information required for driving the inference schemes. Results will be presented from two approaches. One is based on a regression approach that utilizes a wide range of simulations using MODTRAN, SeeBor Version 5.0 global atmospheric profiles and. The second approach uses MERRA-2 reanalysis fields with the RTTOV radiative transfer model approach to derive LST from the LEO satellites, adjusted for the GEO characteristics. The advantage of this latter approach is in the consistency between this retrieval approaches and those used at JPL

  19. Regolith Advanced Surface Systems Operations Robot Excavator

    NASA Technical Reports Server (NTRS)

    Mueller, Robert P.; Smith, Jonathan D.; Ebert, Thomas; Cox, Rachel; Rahmatian, Laila; Wood, James; Schuler, Jason; Nick, Andrew

    2013-01-01

    The Regolith Advanced Surface Systems Operations Robot (RASSOR) excavator robot is a teleoperated mobility platform with a space regolith excavation capability. This more compact, lightweight design (<50 kg) has counterrotating bucket drums, which results in a net-zero reaction horizontal force due to the self-cancellation of the symmetrical, equal but opposing, digging forces.

  20. A Land Surface Data Assimilation Framework Using the Land Information System: Description and Application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Land Information System (LIS) is a hydrologic modeling framework that integrates various community land surface models, ground and satellite-based observations, and high performance computing and data management tools to enable assessment and prediction of hydrologic conditions at various spatia...

  1. Impact of land use changes on surface warming in China

    NASA Astrophysics Data System (ADS)

    Zhang, Jingyong; Dong, Wenjie; Wu, Lingyun; Wei, Jiangfeng; Chen, Peiyan; Lee, Dong-Kyou

    2005-06-01

    Land use changes such as urbanization, agriculture, pasturing, deforestation, desertification and irrigation can change the land surface heat flux directly, and also change the atmospheric circulation indirectly, and therefore affect the local temperature. But it is difficult to separate their effects from climate trends such as greenhouse-gas effects. Comparing the decadal trends of the observation station data with those of the NCEP/NCAR Reanalysis (NNR) data provides a good method to separate the effects because the NNR is insensitive to land surface changes. The effects of urbanization and other land use changes over China are estimated by using the difference between the station and the NNR surface temperature trends. Our results show that urbanization and other land use changes may contribute to the observed 0.12°C (10yr)-1 increase for daily mean surface temperature, and the 0.20°C (10yr)-1 and 0.03°C (10 yr)-1 increases for the daily minimum and maximum surface temperatures, respectively. The urban heat island effect and the effects of other land-use changes may also play an important role in the diurnal temperature range change. The spatial pattern of the differences in trends shows a marked heterogeneity. The land surface degradation such as deforestation and desertification due to human activities over northern China, and rapidly-developed urbanization over southern China, may have mostly contributed to the increases at stations north of about 38°N and in Southeast China, respectively. Furthermore, the vegetation cover increase due to irrigation and fertilization may have contributed to the decreasing trend of surface temperature over the lower Yellow River Basin. The study illustrates the possible impacts of land use changes on surface temperature over China.

  2. Using water isotopes in the evaluation of land surface models

    NASA Astrophysics Data System (ADS)

    Guglielmo, Francesca; Risi, Camille; Ottlé, Catherine; Bastrikov, Vladislav; Valdayskikh, Victor; Cattani, Olivier; Jouzel, Jean; Gribanov, Konstantin; Nekrasova, Olga; Zacharov, Vyacheslav; Ogée, Jérôme; Wingate, Lisa; Raz-Yaseef, Naama

    2013-04-01

    Several studies show that uncertainties in the representation of land surface processes contribute significantly to the spread in projections for the hydrological cycle. Improvements in the evaluation of land surface models would therefore translate into more reliable predictions of future changes. The isotopic composition of water is affected by phase transitions and, for this reason, is a good tracer for the hydrological cycle. Particularly relevant for the assessment of land surface processes is the fact that bare soil evaporation and transpiration bear different isotopic signatures. Water isotopic measurement could thus be employed in the evaluation of the land surface hydrological budget. With this objective, isotopes have been implemented in the most recent version of the land surface model ORCHIDEE. This model has undergone considerable development in the past few years. In particular, a newly discretised (11 layers) hydrology aims at a more realistic representation of the soil water budget. In addition, biogeophysical processes, as, for instance, the dynamics of permafrost and of its interaction with snow and vegetation, have been included. This model version will allow us to better resolve vertical profiles of soil water isotopic composition and to more realistically simulate the land surface hydrological and isotopic budget in a broader range of climate zones. Model results have been evaluated against temperature profiles and isotopes measurements in soil and stem water at sites located in semi-arid (Yatir), temperate (Le Bray) and boreal (Labytnangi) regions. Seasonal cycles are reasonably well reproduced. Furthermore, a sensitivity analysis investigates to what extent water isotopic measurements in soil water can help constrain the representation of land surface processes, with a focus on the partitioning between evaporation and transpiration. In turn, improvements in the description of this partitioning may help reduce the uncertainties in the land

  3. Real Time Land-Surface Hydrologic Modeling Over Continental US

    NASA Technical Reports Server (NTRS)

    Houser, Paul R.

    1998-01-01

    The land surface component of the hydrological cycle is fundamental to the overall functioning of the atmospheric and climate processes. Spatially and temporally variable rainfall and available energy, combined with land surface heterogeneity cause complex variations in all processes related to surface hydrology. The characterization of the spatial and temporal variability of water and energy cycles are critical to improve our understanding of land surface-atmosphere interaction and the impact of land surface processes on climate extremes. Because the accurate knowledge of these processes and their variability is important for climate predictions, most Numerical Weather Prediction (NWP) centers have incorporated land surface schemes in their models. However, errors in the NWP forcing accumulate in the surface and energy stores, leading to incorrect surface water and energy partitioning and related processes. This has motivated the NWP to impose ad hoc corrections to the land surface states to prevent this drift. A proposed methodology is to develop Land Data Assimilation schemes (LDAS), which are uncoupled models forced with observations, and not affected by NWP forcing biases. The proposed research is being implemented as a real time operation using an existing Surface Vegetation Atmosphere Transfer Scheme (SVATS) model at a 40 km degree resolution across the United States to evaluate these critical science questions. The model will be forced with real time output from numerical prediction models, satellite data, and radar precipitation measurements. Model parameters will be derived from the existing GIS vegetation and soil coverages. The model results will be aggregated to various scales to assess water and energy balances and these will be validated with various in-situ observations.

  4. COMETARY SCIENCE. The landing(s) of Philae and inferences about comet surface mechanical properties.

    PubMed

    Biele, Jens; Ulamec, Stephan; Maibaum, Michael; Roll, Reinhard; Witte, Lars; Jurado, Eric; Muñoz, Pablo; Arnold, Walter; Auster, Hans-Ulrich; Casas, Carlos; Faber, Claudia; Fantinati, Cinzia; Finke, Felix; Fischer, Hans-Herbert; Geurts, Koen; Güttler, Carsten; Heinisch, Philip; Herique, Alain; Hviid, Stubbe; Kargl, Günter; Knapmeyer, Martin; Knollenberg, Jörg; Kofman, Wlodek; Kömle, Norbert; Kührt, Ekkehard; Lommatsch, Valentina; Mottola, Stefano; Pardo de Santayana, Ramon; Remetean, Emile; Scholten, Frank; Seidensticker, Klaus J; Sierks, Holger; Spohn, Tilman

    2015-07-31

    The Philae lander, part of the Rosetta mission to investigate comet 67P/Churyumov-Gerasimenko, was delivered to the cometary surface in November 2014. Here we report the precise circumstances of the multiple landings of Philae, including the bouncing trajectory and rebound parameters, based on engineering data in conjunction with operational instrument data. These data also provide information on the mechanical properties (strength and layering) of the comet surface. The first touchdown site, Agilkia, appears to have a granular soft surface (with a compressive strength of 1 kilopascal) at least ~20 cm thick, possibly on top of a more rigid layer. The final landing site, Abydos, has a hard surface. PMID:26228158

  5. COMETARY SCIENCE. The landing(s) of Philae and inferences about comet surface mechanical properties.

    PubMed

    Biele, Jens; Ulamec, Stephan; Maibaum, Michael; Roll, Reinhard; Witte, Lars; Jurado, Eric; Muñoz, Pablo; Arnold, Walter; Auster, Hans-Ulrich; Casas, Carlos; Faber, Claudia; Fantinati, Cinzia; Finke, Felix; Fischer, Hans-Herbert; Geurts, Koen; Güttler, Carsten; Heinisch, Philip; Herique, Alain; Hviid, Stubbe; Kargl, Günter; Knapmeyer, Martin; Knollenberg, Jörg; Kofman, Wlodek; Kömle, Norbert; Kührt, Ekkehard; Lommatsch, Valentina; Mottola, Stefano; Pardo de Santayana, Ramon; Remetean, Emile; Scholten, Frank; Seidensticker, Klaus J; Sierks, Holger; Spohn, Tilman

    2015-07-31

    The Philae lander, part of the Rosetta mission to investigate comet 67P/Churyumov-Gerasimenko, was delivered to the cometary surface in November 2014. Here we report the precise circumstances of the multiple landings of Philae, including the bouncing trajectory and rebound parameters, based on engineering data in conjunction with operational instrument data. These data also provide information on the mechanical properties (strength and layering) of the comet surface. The first touchdown site, Agilkia, appears to have a granular soft surface (with a compressive strength of 1 kilopascal) at least ~20 cm thick, possibly on top of a more rigid layer. The final landing site, Abydos, has a hard surface.

  6. CARBON SEQUESTRATION ON SURFACE MINE LANDS

    SciTech Connect

    Donald H. Graves; Christopher Barton; Richard Sweigard; Richard Warner

    2005-06-22

    An area planted in 2004 on Bent Mountain in Pike County was shifted to the Department of Energy project to centralize an area to become a demonstration site. An additional 98.3 acres were planted on Peabody lands in western Kentucky and Bent Mountain to bring the total area under study by this project to 556.5 acres as indicated in Table 2. Major efforts this quarter include the implementation of new plots that will examine the influence of differing geologic material on tree growth and survival, water quality and quantity and carbon sequestration. Normal monitoring and maintenance was conducted and additional instrumentation was installed to monitor the new areas planted.

  7. On The Reproducibility of Seasonal Land-surface Climate

    SciTech Connect

    Phillips, T J

    2004-10-22

    The sensitivity of the continental seasonal climate to initial conditions is estimated from an ensemble of decadal simulations of an atmospheric general circulation model with the same specifications of radiative forcings and monthly ocean boundary conditions, but with different initial states of atmosphere and land. As measures of the ''reproducibility'' of continental climate for different initial conditions, spatio-temporal correlations are computed across paired realizations of eleven model land-surface variables in which the seasonal cycle is either included or excluded--the former case being pertinent to climate simulation, and the latter to seasonal anomaly prediction. It is found that the land-surface variables which include the seasonal cycle are impacted only marginally by changes in initial conditions; moreover, their seasonal climatologies exhibit high spatial reproducibility. In contrast, the reproducibility of a seasonal land-surface anomaly is generally low, although it is substantially higher in the Tropics; its spatial reproducibility also markedly fluctuates in tandem with warm and cold phases of the El Nino/Southern Oscillation. However, the overall degree of reproducibility depends strongly on the particular land-surface anomaly considered. It is also shown that the predictability of a land-surface anomaly implied by its reproducibility statistics is consistent with what is inferred from more conventional predictability metrics. Implications of these results for climate model intercomparison projects and for operational forecasts of seasonal continental climate also are elaborated.

  8. Development of high resolution land surface parameters for the Community Land Model

    NASA Astrophysics Data System (ADS)

    Ke, Y.; Leung, L. R.; Huang, M.; Coleman, A. M.; Li, H.; Wigmosta, M. S.

    2012-11-01

    There is a growing need for high-resolution land surface parameters as land surface models are being applied at increasingly higher spatial resolution offline as well as in regional and global models. The default land surface parameters for the most recent version of the Community Land Model (i.e. CLM 4.0) are at 0.5° or coarser resolutions, released with the Community Earth System Model (CESM). Plant Functional Types (PFTs), vegetation properties such as Leaf Area Index (LAI), Stem Area Index (SAI), and non-vegetated land covers were developed using remotely sensed datasets retrieved in late 1990's and the beginning of this century. In this study, we developed new land surface parameters for CLM 4.0, specifically PFTs, LAI, SAI and non-vegetated land cover composition, at 0.05° resolution globally based on the most recent MODIS land cover and improved MODIS LAI products. Compared to the current CLM 4.0 parameters, the new parameters produced a decreased coverage by bare soil and trees, but an increased coverage by shrub, grass, and cropland. The new parameters result in a decrease in global seasonal LAI, with the biggest decrease in boreal forests; however, the new parameters also show a large increase in LAI in tropical forest. Differences between the new and the current parameters are mainly caused by changes in the sources of remotely sensed data and the representation of land cover in the source data. Advantages and disadvantages of each dataset were discussed in order to provide guidance on the use of the data. The new high-resolution land surface parameters have been used in a coupled land-atmosphere model (WRF-CLM) applied to the western US to demonstrate their use in high-resolution modeling. A remapping method from the latitude/longitude grid of the CLM data to the WRF grids with map projection was also demonstrated. Future work will include global offline CLM simulations to examine the impacts of source data resolution and subsequent land parameter

  9. Development of High Resolution Land Surface Parameters for the Community Land Model

    SciTech Connect

    Ke, Yinghai; Leung, Lai-Yung R.; Huang, Maoyi; Coleman, Andre M.; Li, Hongyi; Wigmosta, Mark S.

    2012-11-06

    There is a growing need for high-resolution land surface parameters as land surface models are being applied at increasingly higher spatial resolution offline as well as in regional and global models. The default land surface parameters for the most recent version of the Community Land Model (i.e. CLM 4.0) are at 0.5° or coarser resolutions, released with the Community Earth System Model (CESM). Plant Functional Types (PFTs), vegetation properties such as Leaf Area Index (LAI), Stem Area Index (SAI), and non-vegetated land covers were developed using remotely sensed datasets retrieved in late 1990’s and the beginning of this century. In this study, we developed new land surface parameters for CLM 4.0, specifically PFTs, LAI, SAI and non-vegetated land cover composition, at 0.05° resolution globally based on the most recent MODIS land cover and improved MODIS LAI products. Compared to the current CLM 4.0 parameters, the new parameters produced a decreased coverage by bare soil and trees, but an increased coverage by shrub, grass, and cropland. The new parameters result in a decrease in global seasonal LAI, with the biggest decrease in boreal forests; however, the new parameters also show a large increase in LAI in tropical forest. Differences between the new and the current parameters are mainly caused by changes in the sources of remotely sensed data and the representation of land cover in the source data. Advantages and disadvantages of each dataset were discussed in order to provide guidance on the use of the data. The new high-resolution land surface parameters have been used in a coupled land-atmosphere model (WRF-CLM) applied to the western U.S. to demonstrate their use in high-resolution modeling. A remapping method from the latitude/longitude grid of the CLM data to the WRF grids with map projection was also demonstrated. Future work will include global offline CLM simulations to examine the impacts of source data resolution and subsequent land parameter

  10. Advanced oxidation process sanitization of eggshell surfaces.

    PubMed

    Gottselig, Steven M; Dunn-Horrocks, Sadie L; Woodring, Kristy S; Coufal, Craig D; Duong, Tri

    2016-06-01

    The microbial quality of eggs entering the hatchery represents an important critical control point for biosecurity and pathogen reduction programs in integrated poultry production. The development of safe and effective interventions to reduce microbial contamination on the surface of eggs will be important to improve the overall productivity and microbial food safety of poultry and poultry products. The hydrogen peroxide (H2O2) and ultraviolet (UV) light advanced oxidation process is a potentially important alternative to traditional sanitizers and disinfectants for egg sanitation. The H2O2/UV advanced oxidation process was demonstrated previously to be effective in reducing surface microbial contamination on eggs. In this study, we evaluated treatment conditions affecting the efficacy of H2O2/UV advanced oxidation in order to identify operational parameters for the practical application of this technology in egg sanitation. The effect of the number of application cycles, UV intensity, duration of UV exposure, and egg rotation on the recovery of total aerobic bacteria from the surface of eggs was evaluated. Of the conditions evaluated, we determined that reduction of total aerobic bacteria from naturally contaminated eggs was optimized when eggs were sanitized using 2 repeated application cycles with 5 s exposure to 14 mW cm(-2) UV light, and that rotation of the eggs between application cycles was unnecessary. Additionally, using these optimized conditions, the H2O2/UV process reduced Salmonella by greater than 5 log10 cfu egg(-1) on the surface of experimentally contaminated eggs. This study demonstrates the potential for practical application of the H2O2/UV advanced oxidation process in egg sanitation and its effectiveness in reducing Salmonella on eggshell surfaces. PMID:27030693

  11. Widespread land surface wind decline in the Northern Hemisphere partly attributed to land surface changes

    NASA Astrophysics Data System (ADS)

    Thepaut, J.; Vautard, R.; Cattiaux, J.; Yiou, P.; Ciais, P.

    2010-12-01

    pressure gradients, and modeled winds from weather re-analyses do not exhibit any comparable stilling trends than at surface stations. For instance, large-scale circulation changes captured in the most recent European Centre for Medium Range Weather Forecast re-analysis (ERA-interim) can only explain only up to 10-50% of the wind stilling, depending on the region. In addition, a significant amount of the slow-down could originate from a generalized increase in surface roughness, due for instance to forest growth and expansion, and urbanization. This hypothesis, which could explain up to 60% of the decline, is supported by remote sensing observations and theoretical calculations combined with meso-scale model simulations. For future wind power energy resource, the part of wind decline due to land cover changes is easier to cope with than that due to global atmospheric circulation slow down.

  12. Aerodynamic performance of conventional and advanced design labyrinth seals with solid-smooth abradable, and honeycomb lands. [gas turbine engines

    NASA Technical Reports Server (NTRS)

    Stocker, H. L.; Cox, D. M.; Holle, G. F.

    1977-01-01

    Labyrinth air seal static and dynamic performance was evaluated using solid, abradable, and honeycomb lands with standard and advanced seal designs. The effects on leakage of land surface roughness, abradable land porosity, rub grooves in abradable lands, and honeycomb land cell size and depth were studied using a standard labyrinth seal. The effects of rotation on the optimum seal knife pitch were also investigated. Selected geometric and aerodynamic parameters for an advanced seal design were evaluated to derive an optimized performance configuration. The rotational energy requirements were also measured to determine the inherent friction and pumping energy absorbed by the various seal knife and land configurations tested in order to properly assess the net seal system performance level. Results indicate that: (1) seal leakage can be significantly affected with honeycomb or abradable lands; (2) rotational energy absorption does not vary significantly with the use of a solid-smooth, an abradable, or a honeycomb land; and (3) optimization of an advanced lab seal design produced a configuration that had leakage 25% below a conventional stepped seal.

  13. Evapotranspiration and runoff from large land areas: Land surface hydrology for atmospheric general circulation models

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    A land surface hydrology parameterization for use in atmospheric GCM's is presented. The parameterization incorporates subgrid scale variability in topography, soils, soil moisture and precipitation. The framework of the model is the statistical distribution of a topography-soils index, which controls the local water balance fluxes, and is therefore taken to represent the large land area. Spatially variable water balance fluxes are integrated with respect to the topography-soils index to yield our large topography-soils distribution, and interval responses are weighted by the probability of occurrence of the interval. Grid square averaged land surface fluxes result. The model functions independently as a macroscale water balance model. Runoff ratio and evapotranspiration efficiency parameterizations are derived and are shown to depend on the spatial variability of the above mentioned properties and processes, as well as the dynamics of land surface-atmosphere interactions.

  14. Determination of land surface temperature by using Landsat 8 TIRS: A case study in Erzurum, Turkey

    NASA Astrophysics Data System (ADS)

    Dagliyar, Ayse; Avdan, Ugur; Demircioglu Yildiz, Nalan; Nefeslioglu, Hakan A.

    2015-04-01

    The use of satellite imagery in climate change and environmental studies has increased exponentially in accordance with rapid advancement in satellite technology. Apart from the studies such as determination of potential geothermal zones, volcanology, evaluation of geological structures and lithological units, the research on the effects of urban heat islands is also a crucial topic in climate change studies. Land surface temperature can be calculated by using the thermal bands of satellite images. Landsat 8 satellite launched on February 11th in 2013 carries 2 different sensors which are OLI (Operational Land Imager) and TIRS (Thermal Infrared Sensor) having 12 bit radiometric resolution. In this study, land surface temperature of the urban area and its surrounding in Erzurum was calculated by using the satellite data which was acquired from the Landsat 8 Path/Row 172/32 on July 25th in 2014. Considering the surface emissivity and brightness values, the land surface temperature was evaluated in the study area. In order to validate the predicted land surface temperature values, in-situ land surface temperature measurements which were acquired from the stations of the General Directorate of State Meteorological Service in the city of Erzurum and in the districts Uzundere, İspir, Oltu, Tortum and Hınıs were considered. According to the comparisons, the maximum temperature difference was obtained to be 6.45°C in the Tortum station and the minimum temperature difference was observed to be 1.86°C in the Uzundere station. Additionally, by applying supervised classification on the Landsat 8 imagery, the land-use classes were obtained and the temperature differences observed according to the land-use were also investigated.

  15. Landing on an Unstable Surface Decreases ACL Biomechanical Risk Factors

    PubMed Central

    Shultz, Rebecca; Malone, Maria; Swank, Kat; Andrews, Rob; Braun, Hillary J.; Slider, Amy; Dragoo, Jason L.

    2013-01-01

    Objectives: Quadriceps dominant athletes are at a higher risk for anterior cruciate ligament (ACL) injuries because they lack sufficient hamstring activation resulting in a higher Quadricips: hamstring ratio. Muscular co-contraction (low Q:H) is needed to protect the intra-articular structures of the knee. Exercises that promote co-contraction and proprioception have been shown to reduce quadriceps dominance, enhance knee stability and alter neuromuscular firing patterns. The purpose of this investigation was to examine whether landing on an unstable surface (Bosu Ball) induced a greater amount of co-contraction at the knee compared to a stable surface. Methods: Thirty-one Division I NCAA female athletes performed 3 single leg drop jumps per leg on 2 surfaces. Subjects dropped from a 30 cm step first onto the floor (stable surface), and onto a Bosu ball (unstable surface). Each landing was held for a minimum of 2 seconds. Subjects were familiar with Bosu ball training. Muscle activity of the lateral hamstring and vastus lateralis were used to estimate peak hamstring activity and the Quadriceps:Hamstring (Q:H) co-contraction ratio at the time of peak quadriceps activity. Kinematic data were also collected (Vicon) and used to evaluate the following peak measurements: knee flexion angle, hip flexion angle, and trunk flexion and sway angles (Visual3D). All variables were assessed between the time of landing and the end of deceleration. A 1-level ANOVA was used to test for significant differences across the sports in for each variable of interest. Significance was set at p<0.05. Results: Max co-contraction (Q:H) was significantly reduced when athletes landed on an unstable surface (45% lower, p<0.01 Table 1, Figure 1A) compared to the stable surface. Peak hamstring activity was higher when landing on an unstable surface (15% higher, p=0.05, Table 1) compared to a stable surface. Peak knee flexion angles were 21% greater when athletes landed on a stable surface compared

  16. CARBON SEQUESTRATION OF SURFACE MINE LANDS

    SciTech Connect

    Donald H. Graves; Christopher Barton; Richard Sweigard; Richard Warner

    2004-05-19

    The January-March 2004 Quarter was dedicated to tree planting activities in two locations in Kentucky. During year one of this project there was no available mine land to plant in the Hazard area so 107 acres were planted in the Martin county mine location. This year 120 acres was planted in the Hazard area to compensate for the prior year and an additional 57 acres was planted on Peabody properties in western Kentucky. An additional set of special plots were established on each of these areas that contained 4800 seedlings each for special carbon sequestration determinations. Plantings were also conducted to continue compaction and water quality studies on two newly established areas as well as confirmed measurements on the first years plantings. Total plantings on this project now amount to 357 acres containing 245,960 tree seedlings.

  17. Historical Landsat data comparisons: illustrations of land surface change

    USGS Publications Warehouse

    Cross, Matthew D.

    1990-01-01

    This booklet provides an overview of the Landsat program and shows the application of the data to monitor changes occurring on the surface of the Earth. To show changes that have taken place within the last 20 years or less, image pairs were constructed from the Landsat multispectral scanner (MSS) and thematic mapper (TM) sensors. Landsat MSS data provide a historical global record of the land surface from the early 1970's to present. Landsat TM data provide land surface information from the early 1980's to present.

  18. Results from Global Land-Surface Data Assimilation Methods

    NASA Technical Reports Server (NTRS)

    Radakovich, Jon D.; Houser, Paul R.; daSilva, Arlindo; Bosilovich, Michael G.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Realistic representation of the land surface is crucial in global climate modeling (GCM). Recently, the Mosaic land-surface Model (LSM) has been driven off-line using GEOS DAS (Goddard Earth Observing System Data Assimilation System) atmospheric forcing, forming the Off-line Land-surface Global Assimilation (OLGA) system. This system provides a computationally efficient test bed for land surface data assimilation. Here, we validate the OLGA simulation of surface processes and the assimilation of ISCCP surface temperatures. Another component of this study as the incorporation of the Physical-space Statistical Analysis System (PSAS) into OLGA, in order to assimilate surface temperature observations from the International Satellite Cloud Climatology Project (ISCCP). To counteract the subsequent forcing of the analyzed skin temperature back to the initial state following the analysis. incremental bias correction (IBC) was included in the assimilation. The IBC scheme effectively removed the time mean bias, but did not remove him in the mean diurnal cycle. Therefore, a diurnal him correction (DBC) scheme was developed, where the time-dependent bias was modeled with a sine wave parameterization. In addition, quality control of the ISCCP data and anisotropic temperature correction were implemented in PSAS. Preliminary results showed a substantial impact from the inclusion of PSAS and DBC that was visible in the surface meteorology fields and energy budget. Also, the monthly mean diurnal cycle from the experiment closely matched the diurnal cycle from the observations.

  19. Carbon Sequestration on Surface Mine Lands

    SciTech Connect

    Donald H. Graves; Christopher Barton; Bon Jun Koo; Richard Sweigard; Richard Warner

    2004-11-30

    The first quarter of 2004 was dedicated to tree planting activities in two locations in Kentucky. During the first year of this project there was not available mine land to plant in the Hazard area, so 107 acres were planted in the Martin County mine location. This year 120 acres were planted in the Hazard area to compensate for the prior year and an additional 57 acres were planted on Peabody properties in western Kentucky. Additional sets of special plots were established on each of these areas that contained 4800 seedlings each for carbon sequestration demonstrations. Plantings were also conducted to continue compaction and water quality studies on the newly established areas as well as continual measurements of the first year's plantings. Total plantings on this project now amount to 357 acres containing 245,960 seedlings. During the second quarter of this year monitoring systems were established for all the new research areas. Weather data pertinent to the research as well as hydrology and water quality monitoring continues to be conducted on all areas. Studies established to assess specific questions pertaining to carbon flux and the invasion of the vegetation by small mammals are being quantified. Experimental practices initiated with this research project will eventually allow for the planting on long steep slopes with loose grading systems and allow mountain top removal areas to be constructed with loose spoil with no grading of the final layers of rooting material when establishing trees for the final land use designation. Monitoring systems have been installed to measure treatment effects on both above and below ground carbon and nitrogen pools in the planting areas. Soil and tissue samples were collected from both years planting and analyses were conducted in the laboratory. Examination of decomposition and heterotropic respiration on carbon cycling in the reforestation plots continued during the reporting period. Entire planted trees were extracted

  20. CARBON SEQUESTRATION ON SURFACE MINE LANDS

    SciTech Connect

    Donald H. Graves; Christopher Barton; Richard Sweigard; Richard Warner

    2001-01-30

    The October-December 2003 Quarter was dedicated to analyzing the first years tree planting activities and evaluation of the results. This included the analyses of the species success at each of the sites and quantifying the baseline data for future year determination of research levels of mixes. The small mammal colonization study of revegetated surface mines was also initiated and sampling systems initiated.

  1. Improving land surface emissivty parameter for land surface models using portable FTIR and remote sensing observation in Taklimakan Desert

    NASA Astrophysics Data System (ADS)

    Liu, Yongqiang; Mamtimin, Ali; He, Qing

    2014-05-01

    Because land surface emissivity (ɛ) has not been reliably measured, global climate model (GCM) land surface schemes conventionally set this parameter as simply assumption, for example, 1 as in the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) model, 0.96 for soil and wetland in the Global and Regional Assimilation and Prediction System (GRAPES) Common Land Model (CoLM). This is the so-called emissivity assumption. Accurate broadband emissivity data are needed as model inputs to better simulate the land surface climate. It is demonstrated in this paper that the assumption of the emissivity induces errors in modeling the surface energy budget over Taklimakan Desert where ɛ is far smaller than original value. One feasible solution to this problem is to apply the accurate broadband emissivity into land surface models. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument has routinely measured spectral emissivities in six thermal infrared bands. The empirical regression equations have been developed in this study to convert these spectral emissivities to broadband emissivity required by land surface models. In order to calibrate the regression equations, using a portable Fourier Transform infrared (FTIR) spectrometer instrument, crossing Taklimakan Desert along with highway from north to south, to measure the accurate broadband emissivity. The observed emissivity data show broadband ɛ around 0.89-0.92. To examine the impact of improved ɛ to radiative energy redistribution, simulation studies were conducted using offline CoLM. The results illustrate that large impacts of surface ɛ occur over desert, with changes up in surface skin temperature, as well as evident changes in sensible heat fluxes. Keywords: Taklimakan Desert, surface broadband emissivity, Fourier Transform infrared spectrometer, MODIS, CoLM

  2. Influence of atmospheric forcing parameters on land surface simulation

    NASA Astrophysics Data System (ADS)

    Nayak, H. P.; Mandal, M.; Bhattacharya, A.

    2015-12-01

    The quality of atmospheric forcing plays important role on land surface simulation using decoupled land surface modeling system. In the present study, the influence of the various atmospheric forcing parameters on land surface simulation is assessed through sensitivity experiments. Numerical experiments are conducted towards preparation of land surface analysis for the period Jan-2011 - Dec-2013 using offline 2D-Noah land surface model (LSM) based land data assimilation system (LDAS) over Indian region (5 - 39N, 60 - 100E) hereafter referred as LDASI. The surface temperature, specific humidity, horizontal winds and pressure as atmospheric forcing parameters are derived from Modern-Era Retrospective Analysis for Research and Applications (MERRA). The downward (solar and thermal) radiation and precipitation is obtained from European Centre for Medium Range Forecast (ECMWF) and Tropical Rainfall Measuring Mission (TRMM) respectively. The sensitivity experiments are conducted by introducing perturbation in one atmospheric forcing parameter at a time keeping the other parameters unchanged. Influence of temperature, specific humidity, downward (shortwave and long wave) radiation, rain-rate and wind speed is investigated by conducted 13 numerical experiments. It is observed that the land surface analysis from LDASI is most sensitive to the downward longwave radiation and least sensitive to wind speed. The analysis is also substantially influenced by the surface air temperature. The annual mean soil moisture at 5 cm is decreased by 12-15% if the downward long-wave radiation is increased by 20% and it is increased by 15% if the downward long-wave radiation is decreased by 20%. The influence is even more in the Himalayan region but the increase in long-wave radiation leads to increase in soil moisture and similar influence on decrease because downward long-wave radiation leads glacier melting. The annual mean soil temperature in the analysis is increased by 2.2 K if surface

  3. Radiative Properties of Smoke and Aerosol Over Land Surfaces

    NASA Technical Reports Server (NTRS)

    King, Michael D.

    2000-01-01

    This talk discusses smoke and aerosol's radiative properties with particular attention to distinguishing the measurement over clear sky from clouds over land, sea, snow, etc. surfaces, using MODIS Airborne Simulator data from (Brazil, arctic sea ice and tundra and southern Africa, west Africa, and other ecosystems. This talk also discusses the surface bidirectional reflectance using Cloud Absorption Radiometer, BRDF measurements of Saudi Arabian desert, Persian Gulf, cerrado and rain forests in Brazil, sea ice, tundra, Atlantic Ocean, Great Dismal Swamp, Kuwait oil fire smoke. Recent upgrades to instrument (new TOMS UVA channels at 340 and 380 planned use in Africa (SAFARI 2000) and possibly for MEIDEX will also be discussed. This talk also plans to discuss the spectral variation of surface reflectance over land and the sensitivity of off-nadir view angles to correlation between visible near-infrared reflectance for use in remote sensing of aerosol over land.

  4. Automation of SimSphere Land Surface Model Use as a Standalone Application and Integration With EO Data for Deriving Key Land Surface Parameters

    NASA Astrophysics Data System (ADS)

    Petropoulos, George P.; Konstas, Ioannis; Carlson, Toby N.

    2013-04-01

    Use of simulation process models has played a key role in extending our abilities to study Earth system processes and enhancing our understanding on how different components of it interplay. Use of such models combined with Earth Observation (EO) data provides a promising direction towards deriving accurately spatiotemporal estimates of key parameters characterising land surface interactions, by combining the horizontal coverage and spectral resolution of remote sensing data with the vertical coverage and fine temporal continuity of those models. SimSphere is such a software toolkit written in Java for simulating the interactions of soil, vegetation and atmosphere layers of the Earth's land surface. Its use is at present continually expanding worldwide both as an educational and as a research tool for scientific investigations. It is being used either as a stand-alone application or synergistically with EO data. Herein we present recent advancements introduced to SimSphere in different aspects of the model aiming to make its use more robust when used both as a standalone application and synergistically with EO data. We have extensively tested and updated the model code, as well as enhanced it with new functionalities. These included for example taking into account the thermal inertia variation in soil moisture, simulating additional parameters characterising land surface interactions, automating the model use when integrating it with EO data via the "triangle" method and developing batch processing operations. Use of these recently introduced to the model functionalities are illustrated herein using a variety of examples. Our work is significant to the users' community of the model and very timely, given the potential use of SimSphere in an EO-based method being under development for deriving operationally regional estimates of energy fluxes and soil moisture from EO data provided by non-commercial vendors. KEYWORDS: land surface interactions, land surface process

  5. Generating daily high spatial land surface temperatures by combining ASTER and MODIS land surface temperature products for environmental process monitoring.

    PubMed

    Wu, Mingquan; Li, Hua; Huang, Wenjiang; Niu, Zheng; Wang, Changyao

    2015-08-01

    There is a shortage of daily high spatial land surface temperature (LST) data for use in high spatial and temporal resolution environmental process monitoring. To address this shortage, this work used the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM), Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM), and the Spatial and Temporal Data Fusion Approach (STDFA) to estimate high spatial and temporal resolution LST by combining Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) LST and Moderate Resolution Imaging Spectroradiometer (MODIS) LST products. The actual ASTER LST products were used to evaluate the precision of the combined LST images using the correlation analysis method. This method was tested and validated in study areas located in Gansu Province, China. The results show that all the models can generate daily synthetic LST image with a high correlation coefficient (r) of 0.92 between the synthetic image and the actual ASTER LST observations. The ESTARFM has the best performance, followed by the STDFA and the STARFM. Those models had better performance in desert areas than in cropland. The STDFA had better noise immunity than the other two models. PMID:26165141

  6. Accuracy of land surface elevation from CALIPSO mission data

    NASA Astrophysics Data System (ADS)

    Lu, Xiaomei; Hu, Yongxiang

    2015-03-01

    We assess the accuracy of land surface elevation retrieved from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission through comparisons with the U.S. Geological Survey National Elevation Dataset (NED), Shuttle Radar Topography Mission (SRTM), and the altimetry product from the Geoscience Laser Altimeter System onboard the Ice, Cloud, and Land Elevation Satellite (ICESat). The vertical accuracy of the CALIPSO-derived land surface elevation was tested against these three datasets for about 16 million lidar shots over the continental United States. The results show that the CALIPSO-derived elevation was highly correlated with the elevation result from the NED, SRTM, and ICESat datasets. The overall absolute vertical accuracies of the CALIPSO-derived land surface elevation expressed as the root mean square error (RMSE) are 5.58 and 5.90 m when compared with the SRTM and NED results, respectively. Lower accuracy of the CALIPSO-derived land surface elevation was achieved by comparison with the ICESat results (8.35-m RMSE), primarily due to the several kilometers distance between the CALIPSO and ICESat ground footprints. The results show that the variability in terrain, vegetation, canopy, and footprint size can all influence comparisons between the CALIPSO-derived elevation and the results obtained from NED, SRTM, and ICESat datasets.

  7. Impact of irrigation over India on the land surface fluxes

    NASA Astrophysics Data System (ADS)

    de Rosnay, P. R.; Polcher, J. P.; Laval, K. L.; Sabre, M. S.

    2003-04-01

    Irrigation is the main water user in the world with 87 % of the global water consumption being attributed to use on irrigated crop land. There are large spatial variations of the irrigated areas, from 68 % in Asia and 16 % in America, 10 % in Europe and the remaining in Africa and Australia. India is the most important irrigating country in the world with a gross irrigation requirement estimated by the FAO at 457 cubic km by year. The environmental impacts of irrigation are very important: irrigation causes the soil salinization, it affects the water quality and ecology, and increases the incidence of water related diseases. Irrigation is also expected to affect the the land surface energy budget, and thereby the climate system. The work presented here is conducted in the framework of the PROMISE European project. It aims to analyze the sensitivity of the land surface fluxes to the intensive irrigation over Indian peninsula. Numerical experiments are conducted with the land surface scheme ORCHIDEE of the Laboratoire de Meteorologie Dynamique, with a 1 degree spatial resolution. Two 2years simulations, forced by the ISLSCP (1987-88) data sets, are compared, with and without irrigation. The analysis focuses on the effect of land irrigation on the surface fluxes (partition of energy between latent and sensible fluxes), and the river flow.

  8. Land surface modeling and data assimilation with the Land Information System

    NASA Astrophysics Data System (ADS)

    Kumar, S. V.; Peters-Lidard, C. D.; Reichle, R.

    2008-05-01

    The Land Information System (LIS) is a high-resolution, high-performance, land surface modeling and data assimilation system to support a wide range of land surface research activities and applications. LIS integrates various community land surface models, ground and satellite-based observations, and high performance and data management tools to enable assessment and prediction of hydrologic conditions at various spatial and temporal scales of interest. The system has been demonstrated at high spatial resolutions (such as 1km) globally, with the use of scalable computing technologies. The ability of the system to operate at the same fine spatial scales of the atmospheric boundary layer and cloud models enables improved characterization of water and energy cycle processes. LIS has been coupled to the Weather Research and Forecasting (WRF) model, enabling a high-resolution land atmosphere system. Recently, the LIS framework has been enhanced by developing an interoperable extension for sequential data assimilation, thereby providing a comprehensive framework that can integrate data assimilation techniques, hydrologic models, observations and the required computing infrastructure. The capabilities are demonstrated using a suite of experiments that assimilate different sources of observational data into different land surface models to propagate observational information in space and time using assimilation algorithms of varying complexity. These experiments demonstrate the assimilation of various sources of hydrologic observations of soil moisture, snow and skin temperature using different sequential data assimilation algorithms into the land surface models operating in LIS. Several functional extensions to LIS, including an on-line, dynamic bias correction component, and generic support for parameter estimation are also being developed. The integrated use of these key modeling capabilities demonstrates the use of LIS framework as a valuable tool in the development

  9. SGP Cloud and Land Surface Interaction Campaign (CLASIC): Measurement Platforms

    SciTech Connect

    MA Miller; R Avissar; LK Berg; SA Edgerton; ML Fischer; TJ Jackson; B. Kustas; PJ Lamb; G McFarquhar; Q Min; B Schmid; MS Torn; DD Tuner

    2007-06-01

    The Cloud and Land Surface Interaction Campaign (CLASIC) will be conducted from June 8 to June 30, 2007, at the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site. Data will be collected using eight aircraft equipped with a variety of specialized sensors, four specially instrumented surface sites, and two prototype surface radar systems. The architecture of CLASIC includes a high-altitude surveillance aircraft and enhanced vertical thermodynamic and wind profile measurements that will characterize the synoptic scale structure of the clouds and the land surface within the ACRF SGP site. Mesoscale and microscale structures will be sampled with a variety of aircraft, surface, and radar observations. An overview of the measurement platforms that will be used during the CLASIC are described in this report. The coordination of measurements, especially as it relates to aircraft flight plans, will be discussed in the CLASIC Implementation Plan.

  10. The impact of land use and land cover changes on land surface temperature in a karst area of China.

    PubMed

    Xiao, Honglin; Weng, Qihao

    2007-10-01

    Satellite images have been used extensively to study temporal changes in land use and land cover (LULC) in China. However, few studies have been conducted in the karst areas despite the large area and population involved and the fragile ecosystem. In this study, LULC changes were examined in part of Guizhou Province of southern China from 1991 to 2001 based on Landsat Thematic Mapper (TM) images of November 7, 1991, December 5, 1994, and December 19, 2001. Land surface temperature (LST) and normalized difference vegetation index (NDVI) were computed based on LULC types. The results show that agricultural land decreased, while urban areas expanded dramatically, and forest land increased slightly. Barren land increased from 1991 to 1994, and then decreased from 1994 to 2001. These changes in LULC widened the temperature difference between the urban and the rural areas. The change in LST was mainly associated with changes in construction materials in the urban area and in vegetation abundance both in the urban and rural areas. Vegetation had a dual function in the temperatures of different LULC types. While it could ease the warming trend in the urban or built-up areas, it helped to keep other lands warmer in the cold weather. The study also reveals that due to the government's efforts on reforestation, rural ecosystems in some of the study area were being restored. The time required for the karst ecosystem to recover was shorter than previously thought.

  11. CARBON SEQUESTRATION ON SURFACE MINE LANDS

    SciTech Connect

    Donald H. Graves; Christopher Barton; Richard Sweigard; Richard Warner

    2004-08-02

    The April-June 2004 quarter was dedicated to the establishment of monitoring systems for all the new research areas. Hydrology and water quality monitoring continues to be conducted on all areas as does weather data pertinent to the research. Studies assessing specific questions pertaining to carbon flux has been established and the invasion of the vegetation by small mammals is being quantified. The approval of two experimental practices associated with this research by the United States Office of Surface Mining was a major accomplishment during this period of time. These experimental practices will eventually allow for tree planting on long steep slopes with loose grading systems and for the use of loose dumped spoil on mountain top removal areas with no grading in the final layer of rooting material for tree establishment.

  12. Performance Assessment of New Land-Surface and Planetary Boundary Layer Physics in the WRF-ARW

    EPA Science Inventory

    The Pleim-Xiu land surface model, Pleim surface layer scheme, and Asymmetric Convective Model (version 2) are now options in version 3.0 of the Weather Research and Forecasting model (WRF) Advanced Research WRF (ARW) core. These physics parameterizations were developed for the f...

  13. Advanced surface design for logistics analysis

    NASA Astrophysics Data System (ADS)

    Brown, Tim R.; Hansen, Scott D.

    The development of anthropometric arm/hand and tool models and their manipulation in a large system model for maintenance simulation are discussed. The use of Advanced Surface Design and s-fig technology in anthropometrics, and three-dimensional graphics simulation tools, are found to achieve a good balance between model manipulation speed and model accuracy. The present second generation models are shown to be twice as fast to manipulate as the first generation b-surf models, to be easier to manipulate into various configurations, and to more closely approximate human contours.

  14. Monitoring Land Surface Soil Moisture from Space with in-Situ Sensors Validation: The Huntsville Example

    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.

  15. Regolith Advanced Surface Systems Operations Robot (RASSOR)

    NASA Technical Reports Server (NTRS)

    Mueller, Robert P.; Smith, Jonathan D.; Cox, Rachel E.; Schuler, Jason M.; Ebert, Tom; Nick, Andrew J.

    2012-01-01

    Regolith is abundant on extra-terrestrial surfaces and is the source of many resources such as oxygen, hydrogen, titanium, aluminum, iron, silica and other valuable materials, which can be used to make rocket propellant, consumables for life support, radiation protection barrier shields, landing pads, blast protection berms, roads, habitats and other structures and devices. Recent data from the Moon also indicates that there are substantial deposits of water ice in permanently shadowed crater regions and possibly under an over burden of regolith. The key to being able to use this regolith and acquire the resources, is being able to manipulate it with robotic excavation and hauling machinery that can survive and operate in these very extreme extra-terrestrial surface environments. In addition, the reduced gravity on the Moon, Mars, comets and asteroids poses a significant challenge in that the necessary reaction force for digging cannot be provided by the robot's weight as is typically done on Earth. Space transportation is expensive and limited in capacity, so small, lightweight payloads are desirable, which means large traditional excavation machines are not a viable option. A novel, compact and lightweight excavation robot prototype for manipulating, excavating, acquiring, hauling and dumping regolith on extra-terrestrial surfaces has been developed and tested. Lessons learned and test results will be presented including digging in a variety of lunar regolith simulant conditions including frozen regolith mixed with water ice.

  16. Carbon Sequestration on Surface Mine Lands

    SciTech Connect

    Donald H. Graves; Christopher Barton; Richard Sweigard; Richard Warner

    2005-10-02

    During this quarter a general forest monitoring program was conducted to measure treatment effects on above ground and below ground carbon C and Nitrogen (N) pools for the tree planting areas. Detailed studies to address specific questions pertaining to Carbon cycling was initiated with the development of plots to examine the influence of mycorrhizae, spoil chemical and mineralogical properties, and use of amendment on forest establishment and carbon sequestration. Efforts continued during this period to examine decomposition and heterotrophic respiration on C cycling in the reforestation plots. Projected climate change resulting from elevated atmospheric carbon dioxide has given rise to various strategies to sequester carbon in various terrestrial ecosystems. Reclaimed surface mine soils present one such potential carbon sink where traditional reclamation objectives can complement carbon sequestration. New plantings required the modification and design and installation on monitoring equipment. Maintenance and data monitoring on past and present installations are a continuing operation. The Department of Mining Engineering continued the collection of penetration resistance, penetration depth, and bulk density on both old and new treatment areas. Data processing and analysis is in process for these variables. Project scientists and graduate students continue to present results at scientific meetings, tours and field days presentations of the research areas are being conducted on a request basis.

  17. A role for AVIRIS in the Landsat and Advanced Land Remote Sensing Systems program

    NASA Technical Reports Server (NTRS)

    Green, Robert O.; Simmonds, John J.

    1993-01-01

    As a calibrated imaging spectrometer flying at a 20 km altitude, AVIRIS may contribute to the Landsat and the Advanced Land Remote Sensing System efforts. These contributions come in the areas of: (1) on-orbit calibration, (2) specification of new spectral bands, (3) validation of algorithms, and (4) investigation of an imaging spectrometer of the Advanced Land Remote Sensing System.

  18. Land-surface processes and monsoon climate system

    NASA Astrophysics Data System (ADS)

    Xue, Yongkang; De Sales, Fernando; Lau, William; Boone, Arron; Mechoso, Carlos

    2015-04-01

    Yongkang Xue, F. De Sales, B. Lau, A. Boone, C. R. Mechoso Differential thermal heating of land and ocean and heat release into the atmosphere are important factors that determine the onset, strength, duration and spatial distribution of large-scale monsoons. A global and seasonal assessment of land surface process (LSP) effects on the monsoon system has been made based on general circulation models (GCM) coupled to different benchmark land models, which physically represent either comprehensive, or partial, or minimal LSP representations. Observed precipitation is applied as constrain and differences in simulation error are used to assess the effect of the LSP with different complexity. The AGCM results indicate that the land/atmosphere interaction has substantial impact on global water cycle, while the monsoon regions have had strongest impact at intraseasonal to decadal scales. Among monsoon regions, West Africa, South Asia, East Asia, and Amazon regions have largest impact while some monsoon regions have less impact due to strong air/sea interactions and narrow land mass there. LSP reduces the annual precipitation error by 58% over global monsoon regions, about 35% observed precipitation. The partial LSP effect (excluding soil moisture and vegetation albedo) reduces annual precipitation error over monsoon region that equals to about 13% of observed precipitation. The LSP affects the monsoon evolution through different mechanisms at different scales. It affects the surface energy balance and energy partitioning in latent and sensible heat, the atmospheric heating rate, and general circulation. The LSP effects have also been assessed in the land use land cover change experiment. Based on recently compiled global land-use data from 1948-2005, the GCM simulation results indicate the degradation in Mexico, West Africa, south and East Asia and South America produce substantial precipitation anomalies, some of which are consistent with observed regional precipitation

  19. Land-surface influences on weather and climate

    NASA Technical Reports Server (NTRS)

    Baer, F.; Mintz, Y.

    1984-01-01

    Land-surface influences on weather and climate are reviewed. The interrelationship of vegetation, evapotranspiration, atmospheric circulation, and climate is discussed. Global precipitation, soil moisture, the seasonal water cycle, heat transfer, and atmospheric temperature are among the parameters considered in the context of a general biosphere model.

  20. Applications of Land Surface Temperature from Microwave Observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface temperature (LST) is a key input for physically-based retrieval algorithms of hydrological states and fluxes. Yet, it remains a poorly constrained parameter for global scale studies. The main two observational methods to remotely measure T are based on thermal infrared (TIR) observation...

  1. Experimental and analytical studies of advanced air cushion landing systems

    NASA Technical Reports Server (NTRS)

    Lee, E. G. S.; Boghani, A. B.; Captain, K. M.; Rutishauser, H. J.; Farley, H. L.; Fish, R. B.; Jeffcoat, R. L.

    1981-01-01

    Several concepts are developed for air cushion landing systems (ACLS) which have the potential for improving performance characteristics (roll stiffness, heave damping, and trunk flutter), and reducing fabrication cost and complexity. After an initial screening, the following five concepts were evaluated in detail: damped trunk, filled trunk, compartmented trunk, segmented trunk, and roll feedback control. The evaluation was based on tests performed on scale models. An ACLS dynamic simulation developed earlier is updated so that it can be used to predict the performance of full-scale ACLS incorporating these refinements. The simulation was validated through scale-model tests. A full-scale ACLS based on the segmented trunk concept was fabricated and installed on the NASA ACLS test vehicle, where it is used to support advanced system development. A geometrically-scaled model (one third full scale) of the NASA test vehicle was fabricated and tested. This model, evaluated by means of a series of static and dynamic tests, is used to investigate scaling relationships between reduced and full-scale models. The analytical model developed earlier is applied to simulate both the one third scale and the full scale response.

  2. Sharpening advanced land imager multispectral data using a sensor model

    USGS Publications Warehouse

    Lemeshewsky, G.P.; ,

    2005-01-01

    The Advanced Land Imager (ALI) instrument on NASA's Earth Observing One (EO-1) satellite provides for nine spectral bands at 30m ground sample distance (GSD) and a 10m GSD panchromatic band. This report describes an image sharpening technique where the higher spatial resolution information of the panchromatic band is used to increase the spatial resolution of ALI multispectral (MS) data. To preserve the spectral characteristics, this technique combines reported deconvolution deblurring methods for the MS data with highpass filter-based fusion methods for the Pan data. The deblurring process uses the point spread function (PSF) model of the ALI sensor. Information includes calculation of the PSF from pre-launch calibration data. Performance was evaluated using simulated ALI MS data generated by degrading the spatial resolution of high resolution IKONOS satellite MS data. A quantitative measure of performance was the error between sharpened MS data and high resolution reference. This report also compares performance with that of a reported method that includes PSF information. Preliminary results indicate improved sharpening with the method reported here.

  3. The Project for Intercomparison of Land-surface Parameterization Schemes

    NASA Technical Reports Server (NTRS)

    Henderson-Sellers, A.; Yang, Z.-L.; Dickinson, R. E.

    1993-01-01

    The Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) is described and the first stage science plan outlined. PILPS is a project designed to improve the parameterization of the continental surface, especially the hydrological, energy, momentum, and carbon exchanges with the atmosphere. The PILPS Science Plan incorporates enhanced documentation, comparison, and validation of continental surface parameterization schemes by community participation. Potential participants include code developers, code users, and those who can provide datasets for validation and who have expertise of value in this exercise. PILPS is an important activity because existing intercomparisons, although piecemeal, demonstrate that there are significant differences in the formulation of individual processes in the available land surface schemes. These differences are comparable to other recognized differences among current global climate models such as cloud and convection parameterizations. It is also clear that too few sensitivity studies have been undertaken with the result that there is not yet enough information to indicate which simplifications or omissions are important for the near-surface continental climate, hydrology, and biogeochemistry. PILPS emphasizes sensitivity studies with and intercomparisons of existing land surface codes and the development of areally extensive datasets for their testing and validation.

  4. Regional scale hydrology with a new land surface processes model

    NASA Technical Reports Server (NTRS)

    Laymon, Charles; Crosson, William

    1995-01-01

    Through the CaPE Hydrometeorology Project, we have developed an understanding of some of the unique data quality issues involved in assimilating data of disparate types for regional-scale hydrologic modeling within a GIS framework. Among others, the issues addressed here include the development of adequate validation of the surface water budget, implementation of the STATSGO soil data set, and implementation of a remote sensing-derived landcover data set to account for surface heterogeneity. A model of land surface processes has been developed and used in studies of the sensitivity of surface fluxes and runoff to soil and landcover characterization. Results of these experiments have raised many questions about how to treat the scale-dependence of land surface-atmosphere interactions on spatial and temporal variability. In light of these questions, additional modifications are being considered for the Marshall Land Surface Processes Model. It is anticipated that these techniques can be tested and applied in conjunction with GCIP activities over regional scales.

  5. Determining the Impacts of Land Cover/use Categories on Land Surface Temperature Using LANDSAT8-OLI

    NASA Astrophysics Data System (ADS)

    Bektas Balcik, F.; Ergene, E. M.

    2016-06-01

    Due to unplanned and uncontrolled expansion of urban areas, rural land cover types have been replaced with artificial materials. As a result of these replacements, a wide range of negative environmental impacts seriously impacting human health, natural areas, ecosystems, climate, energy efficiency, and quality of living in town center. In this study, the impact of land surface temperature with respect to land cover and land use categories is investigated and evaluated for Istanbul, Turkey. Land surface temperature data was extracted from 21 October 2014 dated Landsat 8 OLI data using mono-window algorithm. In order to extract land use/cover information from remotely sensed data wetness, greenness and brightness components were derived using Tasseled Cap Transformation. The statistical relationship between land surface temperature and Tasseled Cap Transformation components in Istanbul was analyzed using the regression methods. Correlation between Land Surface Temperature and Meteorological Stations Temperature calculated %74.49.

  6. Monitoring urban land cover change by updating the national land cover database impervious surface products

    USGS Publications Warehouse

    Xian, G.; Homer, C.

    2009-01-01

    The U.S. Geological Survey (USGS) National Land Cover Database (NLCD) 2001 is widely used as a baseline for national land cover and impervious conditions. To ensure timely and relevant data, it is important to update this base to a more recent time period. A prototype method was developed to update the land cover and impervious surface by individual Landsat path and row. This method updates NLCD 2001 to a nominal date of 2006 by using both Landsat imagery and data from NLCD 2001 as the baseline. Pairs of Landsat scenes in the same season from both 2001 and 2006 were acquired according to satellite paths and rows and normalized to allow calculation of change vectors between the two dates. Conservative thresholds based on Anderson Level I land cover classes were used to segregate the change vectors and determine areas of change and no-change. Once change areas had been identified, impervious surface was estimated for areas of change by sampling from NLCD 2001 in unchanged areas. Methods were developed and tested across five Landsat path/row study sites that contain a variety of metropolitan areas. Results from the five study areas show that the vast majority of impervious surface changes associated with urban developments were accurately captured and updated. The approach optimizes mapping efficiency and can provide users a flexible method to generate updated impervious surface at national and regional scales. ?? 2009 IEEE.

  7. Impacts of Climate Change and Land use Changes on Land Surface Radiation and Energy Budgets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface radiation and energy budgets are critical to address a variety of scientific and application issues related to climate trends, weather predictions, hydrologic and biogeophysical modeling, and the monitoring of ecosystem health and agricultural crops. This is an introductory paper to t...

  8. The impact of land use on microbial surface water pollution.

    PubMed

    Schreiber, Christiane; Rechenburg, Andrea; Rind, Esther; Kistemann, Thomas

    2015-03-01

    Our knowledge relating to water contamination from point and diffuse sources has increased in recent years and there have been many studies undertaken focusing on effluent from sewage plants or combined sewer overflows. However, there is still only a limited amount of microbial data on non-point sources leading to diffuse pollution of surface waters. In this study, the concentrations of several indicator micro-organisms and pathogens in the upper reaches of a river system were examined over a period of 16 months. In addition to bacteria, diffuse pollution caused by Giardia lamblia and Cryptosporidium spp. was analysed. A single land use type predestined to cause high concentrations of all microbial parameters could not be identified. The influence of different land use types varies between microbial species. The microbial concentration in river water cannot be explained by stable non-point effluent concentrations from different land use types. There is variation in the ranking of the potential of different land use types resulting in surface water contamination with regard to minimum, median and maximum effects. These differences between median and maximum impact indicate that small-scale events like spreading manure substantially influence the general contamination potential of a land use type and may cause increasing micro-organism concentrations in the river water by mobilisation during the next rainfall event. PMID:25456147

  9. Accuracy assessment of NLCD 2006 land cover and impervious surface

    USGS Publications Warehouse

    Wickham, James D.; Stehman, Stephen V.; Gass, Leila; Dewitz, Jon; Fry, Joyce A.; Wade, Timothy G.

    2013-01-01

    Release of NLCD 2006 provides the first wall-to-wall land-cover change database for the conterminous United States from Landsat Thematic Mapper (TM) data. Accuracy assessment of NLCD 2006 focused on four primary products: 2001 land cover, 2006 land cover, land-cover change between 2001 and 2006, and impervious surface change between 2001 and 2006. The accuracy assessment was conducted by selecting a stratified random sample of pixels with the reference classification interpreted from multi-temporal high resolution digital imagery. The NLCD Level II (16 classes) overall accuracies for the 2001 and 2006 land cover were 79% and 78%, respectively, with Level II user's accuracies exceeding 80% for water, high density urban, all upland forest classes, shrubland, and cropland for both dates. Level I (8 classes) accuracies were 85% for NLCD 2001 and 84% for NLCD 2006. The high overall and user's accuracies for the individual dates translated into high user's accuracies for the 2001–2006 change reporting themes water gain and loss, forest loss, urban gain, and the no-change reporting themes for water, urban, forest, and agriculture. The main factor limiting higher accuracies for the change reporting themes appeared to be difficulty in distinguishing the context of grass. We discuss the need for more research on land-cover change accuracy assessment.

  10. South American Monsoon and the Land Surface Processes

    NASA Astrophysics Data System (ADS)

    Xue, Y.; de Sales, F. H.; Li, W.; Mechoso, C. R.; Nobre, C. A.; Juang, H. H.

    2002-12-01

    In this numerical modeling study, the NCEP GCM is applied to investigate the interactions between land surface processes and climate, particularly the effects of land processes on the South American monsoon system (SAMS). A model version with spectral triangular 42 truncation (T42) is used. The corresponding Gaussian grid for T42 is 128 by 64, which is roughly equivalent to 2.8 degrees in latitude and longitude. Two land surface parameterizations are used. One is the Simplified Simple Biosphere Model (SSiB), which includes explicit vegetation representation. The other parameterization is a surface model with two-soil layers (SOIL) and no explicit vegetation scheme. Two 12-month long simulations were performed with the two parameterizations from initial conditions corresponding to May 1, 1987 and identical distributions of soil moisture and surface albedo. The simulations will be referred to as NCEP GCM/SOIL and NCEP GCM/SSiB. The simulations, therefore, differ in the land surface parameterizations and land cover conditions: one with vegetation and the other with only soil layers (but monthly mean vegetation albedo). This experiment aims to test the role of explicit description of vegetation process in the climate model and hence the role of vegetation in the South American hydrometeorology. SAMS starts developing in Central America and then moves southeast towards the Amazons in South America. Afterwards, largest precipitation moves northward and eventually retreats northwest. NCEP GCM/SOIL and NCEP GCM/SSiB produce substantially different evolution and spatial distributions of SAMS. In the NCEP GCM/SOIL, the development of SAMS is too fast and too strong with no clear indication of the southward movement. Rainfall magnitudes are much stronger than in the observation. The NCEP/SSiB, on the other hand, correctly simulates SAMS evolution. To understand the mechanisms that contributed to the differences in the simulations, the surface energy and water balances are

  11. Correcting for Atmospheric Spatial Variability When Estimating Surface Fluxes from Remotely Sensed Land Surface Data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efforts to monitor the terrestrial water cycle require accurate estimates of evapotranspiration over the global land area. Flux towers provide valuable site-level data, but their collective footprints cover only a very small fraction of the land surface. Satellite remote sensing instruments, on th...

  12. Land-surface processes and monsoon climate system

    NASA Astrophysics Data System (ADS)

    Xue, Y.

    2014-12-01

    Differential thermal heating of land and ocean and heat release into the atmosphere are important factors that determine the onset, strength, duration and spatial distribution of large-scale monsoons. A global and seasonal assessment of land surface process (LSP) effects on the monsoon system has been made based on general circulation models (GCM) coupled to different benchmark land models, which physically represent either comprehensive, or partial, or minimal LSP representations. Observed precipitation is applied as constrain and differences in simulation error are used to assess the effect of the LSP with different complexity. The AGCM results indicate that the land/atmosphere interaction has substantial impact on global water cycle, while the monsoon regions have had strongest impact at intraseasonal to decadal scales. Among monsoon regions, West Africa, South Asia, East Asia, and Amazon regions have largest impact while some monsoon regions have less impact due to strong air/sea interactions and narrow land mass. LSP reduces the annual precipitation error by 58% over global monsoon regions, about 35% observed precipitation. The partial LSP effect (excluding soil moisture and vegetation albedo) reduces annual precipitation error over monsoon region that equals to about 13% of observed precipitation. It has also been suggested that LSP contribute to the abrupt jump in latitude of the East Asian monsoon as well as general circulation turning in some monsoon regions in its early stages. The LSP effects have also been assessed in the land use land cover change experiment. Based on recently compiled global land-use data from 1948-2005, the GCM simulation results indicate the degradation in Mexico, West Africa, south and East Asia and South America produce substantial precipitation anomalies, some of which are consistent with observed regional precipitation anomalies. More comprehensive studies with multi-models are imperatively necessary.

  13. Use of Sharpened Land Surface Temperature for Daily Evapotranspiration Estimation over Irrigated Crops in Arid Lands

    NASA Astrophysics Data System (ADS)

    Rosas Aguilar, J.; McCabe, M. F.; Houborg, R.; Gao, F.

    2014-12-01

    Satellite remote sensing provides data on land surface characteristics, useful for mapping land surface energy fluxes and evapotranspiration (ET). Land-surface temperature (LST) derived from thermal infrared (TIR) satellite data has been reliably used as a remote indicator of ET and surface moisture status. However, TIR imagery usually operates at a coarser resolution than that of shortwave sensors on the same satellite platform, making it sometimes unsuitable for monitoring of field-scale crop conditions. This study applies the data mining sharpener (DMS; Gao et al., 2012) technique to data from the Moderate Resolution Imaging Spectroradiometer (MODIS), which sharpens the 1 km thermal data down to the resolution of the optical data (250-500 m) based on functional LST and reflectance relationships established using a flexible regression tree approach. The DMS approach adopted here has been enhanced/refined for application over irrigated farming areas located in harsh desert environments in Saudi Arabia. The sharpened LST data is input to an integrated modeling system that uses the Atmosphere-Land Exchange Inverse (ALEXI) model and associated flux disaggregation scheme (DisALEXI) in conjunction with model reanalysis data and remotely sensed data from polar orbiting (MODIS) and geostationary (MSG; Meteosat Second Generation) satellite platforms to facilitate daily estimates of evapotranspiration. Results are evaluated against available flux tower observations over irrigated maize near Riyadh in Saudi Arabia. Successful monitoring of field-scale changes in surface fluxes are of importance towards an efficient water use in areas where fresh water resources are scarce and poorly monitored. Gao, F.; Kustas, W.P.; Anderson, M.C. A Data Mining Approach for Sharpening Thermal Satellite Imagery over Land. Remote Sens. 2012, 4, 3287-3319.

  14. Land Surface Processes Simulation Over Thar Desert in Northwest India

    NASA Astrophysics Data System (ADS)

    Raja, P.; Srinivas, C. V.; Hari Prasad, K. B. R. R.; Singh, Nilendu

    2016-06-01

    Land surface processes in data scarce arid northwestern India and their influence on the regional climate including monsoon are now gaining enhanced scientific attention. In this work the seasonal variation of land surface parameters and surface-energy flux components over Lasiurus sindicus grassland system in Thar Desert, western India were simulated using the mesoscale WRF model. The data on surface fluxes from a micrometeorological station, and basic surface level weather data from the Central Arid Zone Research Institute's experimental field station (26o59'41″N; 71o29'10″E), Jaisalmer, were used for comparison. Simulations were made for typical fair weather days in three seasons [12-14 January (peak winter); 29-31 May (peak summer), 19-21 August (monsoon)] during 2012. Sensitivity experiments conducted using a 5-layer soil thermal diffusion (5TD) scheme and a comprehensive land surface physics scheme (Noah) revealed the 5TD scheme gives large biases in surface fluxes and other land surface parameters. Simulations show large variations in surface fluxes and meteorological parameters in different seasons with high friction velocities, sensible heat fluxes, deep boundary layers in summer and monsoon season as compared to winter. The shortwave radiation is underestimated during the monsoon season, and is overestimated in winter and summer. In general, the model simulated a cold bias in soil temperature in summer and monsoon season and a warm bias in winter; the simulated surface fluxes and air temperature followed these trends. These biases could be due to a negative bias in net radiation resulting from a high bias in downward shortwave radiation in various seasons. The Noah LSM simulated various parameters more realistically in all seasons than the 5TD soil scheme due to inclusion of explicit vegetation processes in the former. The differences in the simulated fluxes with the two LSMs are small in winter and large in summer. The deep mixed layers are

  15. Global Land Surface Emissivity Retrieved From Satellite Ultraspectral IR Measurements

    NASA Technical Reports Server (NTRS)

    Zhou, D. K.; Larar, A. M.; Liu, Xu; Smith, W. L.; Strow, L. L.; Yang, Ping; Schlussel, P.; Calbet, X.

    2011-01-01

    Ultraspectral resolution infrared (IR) radiances obtained from nadir observations provide information about the atmosphere, surface, aerosols, and clouds. Surface spectral emissivity (SSE) and surface skin temperature from current and future operational satellites can and will reveal critical information about the Earth s ecosystem and land-surface-type properties, which might be utilized as a means of long-term monitoring of the Earth s environment and global climate change. In this study, fast radiative transfer models applied to the atmosphere under all weather conditions are used for atmospheric profile and surface or cloud parameter retrieval from ultraspectral and/or hyperspectral spaceborne IR soundings. An inversion scheme, dealing with cloudy as well as cloud-free radiances observed with ultraspectral IR sounders, has been developed to simultaneously retrieve atmospheric thermodynamic and surface or cloud microphysical parameters. This inversion scheme has been applied to the Infrared Atmospheric Sounding Interferometer (IASI). Rapidly produced SSE is initially evaluated through quality control checks on the retrievals of other impacted surface and atmospheric parameters. Initial validation of retrieved emissivity spectra is conducted with Namib and Kalahari desert laboratory measurements. Seasonal products of global land SSE and surface skin temperature retrieved with IASI are presented to demonstrate seasonal variation of SSE.

  16. Impacts of land use and land cover on surface and air temperature in urban landscapes

    NASA Astrophysics Data System (ADS)

    Crum, S.; Jenerette, D.

    2015-12-01

    Accelerating urbanization affects regional climate as the result of changing land cover and land use (LCLU). Urban land cover composition may provide valuable insight into relationships among urbanization, air, and land-surface temperature (Ta and LST, respectively). Climate may alter these relationships, where hotter climates experience larger LULC effects. To address these hypotheses we examined links between Ta, LST, LCLU, and vegetation across an urban coastal to desert climate gradient in southern California, USA. Using surface temperature radiometers, continuously measuring LST on standardized asphalt, concrete, and turf grass surfaces across the climate gradient, we found a 7.2°C and 4.6°C temperature decrease from asphalt to vegetated cover in the coast and desert, respectively. There is 131% more temporal variation in asphalt than turf grass surfaces, but 37% less temporal variation in concrete than turf grass. For concrete and turf grass surfaces, temporal variation in temperature increased from coast to desert. Using ground-based thermal imagery, measuring LST for 24 h sequences over citrus orchard and industrial use locations, we found a 14.5°C temperature decrease from industrial to orchard land use types (38.4°C and 23.9°C, respectively). Additionally, industrial land use types have 209% more spatial variation than orchard (CV=0.20 and 0.09, respectively). Using a network of 300 Ta (iButton) sensors mounted in city street trees throughout the region and hyperspectral imagery data we found urban vegetation greenness, measured using the normalized difference vegetation index (NDVI), was negatively correlated to Ta at night across the climate gradient. Contrasting previous findings, the closest coupling between NDVI and Ta is at the coast from 0000 h to 0800 h (highest r2 = 0.6, P < 0.05) while relationships at the desert are weaker (highest r2 = 0.38, P < 0.05). These findings indicate that vegetation cover in urbanized regions of southern

  17. On the Potential Predictability of Seasonal Land-Surface Climate

    SciTech Connect

    Phillips, T J

    2001-10-01

    The chaotic behavior of the continental climate of an atmospheric general circulation model is investigated from an ensemble of decadal simulations with common specifications of radiative forcings and monthly ocean boundary conditions, but different initial states of atmosphere and land. The variability structures of key model land-surface processes appear to agree sufficiently with observational estimates to warrant detailed examination of their predictability on seasonal time scales. This predictability is inferred from several novel measures of spatio-temporal reproducibility applied to eleven model variables. The reproducibility statistics are computed for variables in which the seasonal cycle is included or excluded, the former case being most pertinent to climate model simulations, and the latter to predictions of the seasonal anomalies. Because the reproducibility metrics in the latter case are determined in the context of a ''perfectly'' known ocean state, they are properly viewed as estimates of the potential predictability of seasonal climate. Inferences based on these reproducibility metrics are shown to be in general agreement with those derived from more conventional measures of potential predictability. It is found that the land-surface variables which include the seasonal cycle are impacted only marginally by changes in initial conditions; moreover, their seasonal climatologies exhibit high spatial reproducibility. In contrast, the reproducibility of a seasonal land-surface anomaly is generally low, although it is considerably higher in the Tropics; its spatial reproducibility also fluctuates in tandem with warm and cold phases of the El Nino/Southern Oscillation phenomenon. However, the detailed sensitivities to initial conditions depend somewhat on the land-surface process: pressure and temperature anomalies exhibit the highest temporal reproducibilities, while hydrological and turbulent flux anomalies show the highest spatial reproducibilities

  18. Atmospheric correction of high resolution land surface images

    NASA Technical Reports Server (NTRS)

    Diner, D. J.; Martonchik, J. V.; Danielson, E. D.; Bruegge, C. J.

    1989-01-01

    Algorithms to correct for atmospheric-scattering effects in high-spatial resolution land-surface images require the ability to perform rapid and accurate computations of the top-of-atmosphere diffuse radiance field for arbitrarily general surface reflectance distributions (which may be both heterogeneous and non-Lambertian) and atmospheric models. Using three-dimensional radiative transfer (3DRT) theory algorithms are being developed. The methodology used to perform the 3DRT calculations is described. It is shown how these calculations are used to perform atmospheric corrections, and the sensitivity of the retrieved surface reflectances to atmospheric structural parameters is illustrated.

  19. Surface plasmon resonance biosensors: advances and applications

    NASA Astrophysics Data System (ADS)

    Homola, Jirí

    2009-10-01

    Surface plasmon resonance (SPR) biosensors represent the most advanced label-free optical affinity biosensor technology. In the last decade numerous SPR sensor platforms have been developed and applied in the life sciences and bioanalytics. This contribution reviews the state of the art in the development of SPR (bio)sensor technology and presents selected results of research into SPR biosensors at the Institute of Photonics and Electronics, Prague. The developments discussed in detail include a miniature fiber optic SPR sensor for localized measurements, a compact SPR sensor for field use and a multichannel SPR sensor for high-throughput screening. Examples of applications for the detection of analytes related to medical diagnostics (biomarkers, hormones, antibodies), environmental monitoring (endocrine disrupting compounds), and food safety (pathogens and toxins) are given.

  20. Advanced Bayesian Method for Planetary Surface Navigation

    NASA Technical Reports Server (NTRS)

    Center, Julian

    2015-01-01

    Autonomous Exploration, Inc., has developed an advanced Bayesian statistical inference method that leverages current computing technology to produce a highly accurate surface navigation system. The method combines dense stereo vision and high-speed optical flow to implement visual odometry (VO) to track faster rover movements. The Bayesian VO technique improves performance by using all image information rather than corner features only. The method determines what can be learned from each image pixel and weighs the information accordingly. This capability improves performance in shadowed areas that yield only low-contrast images. The error characteristics of the visual processing are complementary to those of a low-cost inertial measurement unit (IMU), so the combination of the two capabilities provides highly accurate navigation. The method increases NASA mission productivity by enabling faster rover speed and accuracy. On Earth, the technology will permit operation of robots and autonomous vehicles in areas where the Global Positioning System (GPS) is degraded or unavailable.

  1. Surface EMG in advanced hand prosthetics.

    PubMed

    Castellini, Claudio; van der Smagt, Patrick

    2009-01-01

    One of the major problems when dealing with highly dexterous, active hand prostheses is their control by the patient wearing them. With the advances in mechatronics, building prosthetic hands with multiple active degrees of freedom is realisable, but actively controlling the position and especially the exerted force of each finger cannot yet be done naturally. This paper deals with advanced robotic hand control via surface electromyography. Building upon recent results, we show that machine learning, together with a simple downsampling algorithm, can be effectively used to control on-line, in real time, finger position as well as finger force of a highly dexterous robotic hand. The system determines the type of grasp a human subject is willing to use, and the required amount of force involved, with a high degree of accuracy. This represents a remarkable improvement with respect to the state-of-the-art of feed-forward control of dexterous mechanical hands, and opens up a scenario in which amputees will be able to control hand prostheses in a much finer way than it has so far been possible.

  2. Atmospheric corrections of passive microwave data for estimating land surface temperature.

    PubMed

    Liu, Zeng-Lin; Wu, Hua; Tang, Bo-Hui; Qiu, Shi; Li, Zhao-Liang

    2013-07-01

    Quantitative analysis of the atmospheric effects on observations made by the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) has been performed. The differences between observed brightness temperatures at the top of the atmosphere and at the bottom of the atmosphere were analyzed using a database of simulated observations, which were configured to replicate AMSR-E data. The differences between observed brightness temperatures at the top of the atmosphere and land surface-emitted brightness temperatures were also computed. Quantitative results show that the atmosphere has different effects on brightness temperatures in different AMSR-E channels. Atmospheric effects can be neglected at 6.925 and 10.65 GHz, when the standard deviation is less than 1 K. However, at other frequencies and polarizations, atmospheric effects on observations should not be neglected. An atmospheric correction algorithm was developed at 18.7 GHz vertical polarization, based on the classic split-window algorithm used in thermal remote sensing. Land surface emission can be estimated with RMSE = 0.99 K using the proposed method. Using the known land surface emissivity, Land Surface Temperature (LST) can be retrieved. The RMSE of retrieved LST is 1.17 K using the simulated data.

  3. The effect of landing surface on the plantar kinetics of chinese paratroopers using half-squat landing.

    PubMed

    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 1(st) to 4(th) metatarsal and mid-foot regions, but lower maximal plantar pressure in the 5(th) metatarsal region. Shorter T- MPP was found during hard surface landing in the 1(st) and 2(nd) metatarsal and medial rear foot. Landing on a hard surface landing resulted in a lower PTI than a soft surface in the 1(st)phalangeal region. For Chinese paratroopers, specific foot prosthesis should be designed to protect the1(st) to 4(th)metatarsal region for hard surface landing, and the 1(st)phalangeal and 5(th)metatarsal region for soft surface landing. Key PointsUnderstanding 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 1(st) to 4(th) metatarsal and mid-foot regions, but lower maximal plantar pressure in the 5(th) metatarsal region.A shorter time to maximal plantar pressure was found during a hard surface landing in the 1(st) and 2(nd) 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 1(st) phalangeal region.For Chinese paratroopers, specific foot prosthesis should be designed to protect

  4. Terrestrial Ecosystems - Land Surface Forms of the Conterminous United States

    USGS Publications Warehouse

    Cress, Jill J.; Sayre, Roger G.; Comer, Patrick; Warner, Harumi

    2009-01-01

    As part of an effort to map terrestrial ecosystems, the U.S. Geological Survey has generated land surface form classes to be used in creating maps depicting standardized, terrestrial ecosystem models for the conterminous United States, using an ecosystems classification developed by NatureServe . A biophysical stratification approach, developed for South America and now being implemented globally, was used to model the ecosystem distributions. Since land surface forms strongly influence the differentiation and distribution of terrestrial ecosystems, they are one of the key input layers in this biophysical stratification. After extensive investigation into various land surface form mapping methodologies, the decision was made to use the methodology developed by the Missouri Resource Assessment Partnership (MoRAP). MoRAP made modifications to Hammond's land surface form classification, which allowed the use of 30-meter source data and a 1-km2 window for analyzing the data cell and its surrounding cells (neighborhood analysis). While Hammond's methodology was based on three topographic variables, slope, local relief, and profile type, MoRAP's methodology uses only slope and local relief. Using the MoRAP method, slope is classified as gently sloping when more than 50 percent of the area in a 1-km2 neighborhood has slope less than 8 percent, otherwise the area is considered moderately sloping. Local relief, which is the difference between the maximum and minimum elevation in a neighborhood, is classified into five groups: 0-15 m, 16-30 m, 31-90 m, 91-150 m, and >150 m. The land surface form classes are derived by combining slope and local relief to create eight landform classes: flat plains (gently sloping and local relief = 90 m), low hills (not gently sloping and local relief = 150 m). However, in the USGS application of the MoRAP methodology, an additional local relief group was used (> 400 m) to capture additional local topographic variation. As a result, low

  5. 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.

  6. Utilization of Hydrologic Remote Sensing Data in Land Surface Modeling and Data Assimilation: Current Status and Challenges

    NASA Technical Reports Server (NTRS)

    Kumar, Sujay V.; Peters-Lidard, Christa; Reichl, Rolf; Harrison, Kenneth; Santanello, Joseph

    2010-01-01

    Recent advances in remote sensing technologies have enabled the monitoring and measurement of the Earth's land surface at an unprecedented scale and frequency. The myriad of these land surface observations must be integrated with the state-of-the-art land surface model forecasts using data assimilation to generate spatially and temporally coherent estimates of environmental conditions. These analyses are of critical importance to real-world applications such as agricultural production, water resources management and flood, drought, weather and climate prediction. This need motivated the development of NASA Land Information System (LIS), which is an expert system encapsulating a suite of modeling, computational and data assimilation tools required to address challenging hydrological problems. LIS integrates the use of several community land surface models, use of ground and satellite based observations, data assimilation and uncertainty estimation techniques and high performance computing and data management tools to enable the assessment and prediction of hydrologic conditions at various spatial and temporal scales of interest. This presentation will focus on describing the results, challenges and lessons learned from the use of remote sensing data for improving land surface modeling, within LIS. More specifically, studies related to the improved estimation of soil moisture, snow and land surface temperature conditions through data assimilation will be discussed. The presentation will also address the characterization of uncertainty in the modeling process through Bayesian remote sensing and computational methods.

  7. Analytical simulation and inversion of dynamic urban land surface effects

    NASA Astrophysics Data System (ADS)

    Bayer, P.; Rivera, J.; Blum, P.; Schweizer, D.; Rybach, L.

    2015-12-01

    Long-term thermal changes at the land surface can be backtracked from borehole temperature profiles. The main focus so far has been on past climate changes, assuming perfect coupling of surface air and ground temperature. In many urbanized areas, however, temperature profiles are heavily perturbed. We find a characteristic bending of urban profiles towards shallow depth, which indicates strong heating from the ground surface during recent decades. This phenomenon is generally described as subsurface urban heat island (UHI) effect, which exists beneath many cities worldwide. Major drivers are land use changes and urban structures that act as long-term heat sources that artificially load the top 100 m of the ground. While variability in land use and coverage are critical factors for reliable borehole climatology, temperature profiles can also be inverted to trace back the combined effect of past urbanization and climate. We present an analytical framework based on the superposition of specific Green's functions for simulating transient land use changes and their effects on borehole temperature profiles. By inversion in a Bayesian framework, flexible calibration of unknown spatially distributed parameter values and their correlation is feasible. The procedure is applied to four temperature logs which are around 200-400 m deep from the city and suburbs of Zurich, Switzerland. These were recorded recently by a temperature sensor and data logger introduced in closed borehole heat exchangers before the start of geothermal operation. At the sites, long-term land use changes are well documented for more than the last century. This facilitated focusing on a few unknown parameters, and we selected the contribution by asphalt and by basements of buildings. It is revealed that for three of the four sites, these two factors dominate the subsurface UHI evolution. At one site, additional factors such as buried district heating networks may play a role. It is demonstrated that site

  8. Derived Land Surface Emissivity From Suomi NPP CrIS

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Larar, Allen M.; Liu, Xu

    2012-01-01

    Presented here is the land surface IR spectral emissivity retrieved from the Cross-track Infrared Sounder (CrIS) measurements. The CrIS is aboard the Suomi National Polar-orbiting Partnership (NPP) satellite launched on October 28, 2011. We describe the retrieval algorithm, demonstrate the surface emissivity retrieved with CrIS measurements, and inter-comparison with the Infrared Atmospheric Sounding Interferometer (IASI) emissivity. We also demonstrate that surface emissivity from satellite measurements can be used in assistance of monitoring global surface climate change, as a long-term measurement of IASI and CrIS will be provided by the series of EUMETSAT MetOp and US Joint Polar Satellite System (JPSS) satellites. Monthly mean surface properties are produced using last 5-year IASI measurements. A temporal variation indicates seasonal diversity and El Nino/La Nina effects not only shown on the water but also on the land. Surface spectral emissivity and skin temperature from current and future operational satellites can be utilized as a means of long-term monitoring of the Earth's environment. CrIS spectral emissivity are retrieved and compared with IASI. The difference is small and could be within expected retrieval error; however it is under investigation.

  9. Analysing the Effects of Different Land Cover Types on Land Surface Temperature Using Satellite Data

    NASA Astrophysics Data System (ADS)

    Şekertekin, A.; Kutoglu, Ş. H.; Kaya, S.; Marangoz, A. M.

    2015-12-01

    Monitoring Land Surface Temperature (LST) via remote sensing images is one of the most important contributions to climatology. LST is an important parameter governing the energy balance on the Earth and it also helps us to understand the behavior of urban heat islands. There are lots of algorithms to obtain LST by remote sensing techniques. The most commonly used algorithms are split-window algorithm, temperature/emissivity separation method, mono-window algorithm and single channel method. In this research, mono window algorithm was implemented to Landsat 5 TM image acquired on 28.08.2011. Besides, meteorological data such as humidity and temperature are used in the algorithm. Moreover, high resolution Geoeye-1 and Worldview-2 images acquired on 29.08.2011 and 12.07.2013 respectively were used to investigate the relationships between LST and land cover type. As a result of the analyses, area with vegetation cover has approximately 5 ºC lower temperatures than the city center and arid land., LST values change about 10 ºC in the city center because of different surface properties such as reinforced concrete construction, green zones and sandbank. The temperature around some places in thermal power plant region (ÇATES and ZETES) Çatalağzı, is about 5 ºC higher than city center. Sandbank and agricultural areas have highest temperature due to the land cover structure.

  10. Quantifying Uncertainties in Land Surface Microwave Emissivity Retrievals

    NASA Technical Reports Server (NTRS)

    Tian, Yudong; Peters-Lidard, Christa D.; Harrison, Kenneth W.; Prigent, Catherine; Norouzi, Hamidreza; Aires, Filipe; Boukabara, Sid-Ahmed; Furuzawa, Fumie A.; Masunaga, Hirohiko

    2012-01-01

    Uncertainties in the retrievals of microwave land surface emissivities were quantified over two types of land surfaces: desert and tropical rainforest. Retrievals from satellite-based microwave imagers, including SSM/I, TMI and AMSR-E, were studied. Our results show that there are considerable differences between the retrievals from different sensors and from different groups over these two land surface types. In addition, the mean emissivity values show different spectral behavior across the frequencies. With the true emissivity assumed largely constant over both of the two sites throughout the study period, the differences are largely attributed to the systematic and random errors in the retrievals. Generally these retrievals tend to agree better at lower frequencies than at higher ones, with systematic differences ranging 14% (312 K) over desert and 17% (320 K) over rainforest. The random errors within each retrieval dataset are in the range of 0.52% (26 K). In particular, at 85.0/89.0 GHz, there are very large differences between the different retrieval datasets, and within each retrieval dataset itself. Further investigation reveals that these differences are mostly likely caused by rain/cloud contamination, which can lead to random errors up to 1017 K under the most severe conditions.

  11. Land-surface studies with a directional neutron detector.

    SciTech Connect

    Desilets, Darin; Brennan, James S.; Mascarenhas, Nicholas; Marleau, Peter

    2009-09-01

    Direct measurements of cosmic-ray neutron intensity were recorded with a neutron scatter camera developed at SNL. The instrument used in this work is a prototype originally designed for nuclear non-proliferation work, but in this project it was used to characterize the response of ambient neutrons in the 0.5-10 MeV range to water located on or above the land surface. Ambient neutron intensity near the land surface responds strongly to the presence of water, suggesting the possibility of an indirect method for monitoring soil water content, snow water equivalent depth, or canopy intercepted water. For environmental measurements the major advantage of measuring neutrons with the scatter camera is the limited (60{sup o}) field of view that can be obtained, which allows observations to be conducted at a previously unattainable spatial scales. This work is intended to provide new measurements of directional fluxes which can be used in the design of new instruments for passively and noninvasively observing land-surface water. Through measurements and neutron transport modeling we have demonstrated that such a technique is feasible.

  12. Linking land use with pesticides in Dutch surface waters.

    PubMed

    Van't, Zelfde M T; Tamis, W L M; Vijver, M G; De Snoo, G R

    2012-01-01

    Compared with other European countries The Netherlands has a relatively high level of pesticide consumption, particularly in agriculture. Many of the compounds concerned end up in surface waters. Surface water quality is routinely monitored and numerous pesticides are found to be present in high concentrations, with various standards being regularly exceeded. Many standards-breaching pesticides exhibit regional patterns that can be traced back to land use. These patterns have been statistically analysed by correlating surface area per land use category with standards exceedance per pesticide, thereby identifying numerous significant correlations with respect to breaches of both the ecotoxicological standard (Maximum Tolerable Risk, MTR) and the drinking water standard. In the case of the MTR, greenhouse horticulture, floriculture and bulb-growing have the highest number as well as percentage of standard-breaching pesticides, despite these market segments being relatively small in terms of area cropped. Cereals, onions, vegetables, perennial border plants and pulses are also associated with many pesticides that exceed the drinking water standard. When a correction is made for cropped acreage, cereals and potatoes also prove to be a major contributor to monitoring sites where the MTR standard is exceeded. Over the period 1998-2006 the land-use categories with the most and highest percentage of standards-exceeding pesticides (greenhouse horticulture, bulb-growing and flower cultivation) showed an increase in the percentage of standards-exceeding compounds.

  13. Linking land use with pesticides in Dutch surface waters.

    PubMed

    Van't, Zelfde M T; Tamis, W L M; Vijver, M G; De Snoo, G R

    2012-01-01

    Compared with other European countries The Netherlands has a relatively high level of pesticide consumption, particularly in agriculture. Many of the compounds concerned end up in surface waters. Surface water quality is routinely monitored and numerous pesticides are found to be present in high concentrations, with various standards being regularly exceeded. Many standards-breaching pesticides exhibit regional patterns that can be traced back to land use. These patterns have been statistically analysed by correlating surface area per land use category with standards exceedance per pesticide, thereby identifying numerous significant correlations with respect to breaches of both the ecotoxicological standard (Maximum Tolerable Risk, MTR) and the drinking water standard. In the case of the MTR, greenhouse horticulture, floriculture and bulb-growing have the highest number as well as percentage of standard-breaching pesticides, despite these market segments being relatively small in terms of area cropped. Cereals, onions, vegetables, perennial border plants and pulses are also associated with many pesticides that exceed the drinking water standard. When a correction is made for cropped acreage, cereals and potatoes also prove to be a major contributor to monitoring sites where the MTR standard is exceeded. Over the period 1998-2006 the land-use categories with the most and highest percentage of standards-exceeding pesticides (greenhouse horticulture, bulb-growing and flower cultivation) showed an increase in the percentage of standards-exceeding compounds. PMID:23885409

  14. The Cloud and Land Surface Interaction Campaign (CLASIC)

    NASA Astrophysics Data System (ADS)

    Miller, M. A.

    2008-05-01

    The consequences of increasing greenhouse gas concentrations on the Earth's climate system are evaluated using Global Climate Models, which must accurately simulate the complex array of mechanisms and feedbacks in the climate system and predict how they will operate in the future. A significant challenge for these models is the representation of cumulus convection, which is an important component of the water and energy budget of the planet and plays a key role in the hydrologic cycle. The role of cumulus convection in the water budget is particularly important in semi-arid regions and in regions with significant agricultural interests. In situations where the synoptic scale forcing is weak and the surface is sufficiently moist, continental cumulus convection may be strongly modulated by land surface conditions, while at the same time influencing the land surface itself through rain-induced changes in soil moisture and through its impact on photosynthesis. Many of the properties of the land surface that likely influence the development and evolution of cumulus convection can be altered by human activities such as urban development and agriculture. The Cloud and Land Surface Interaction Campaign (CLASIC) was conducted in the Southern Great Plains of the United States during June 2007. A principal goal of the experiment was to examine these interactions when shallow convection was the dominant cloud type across the SGP domain. The experiment was lead by the Department of Energy's (DOE's) Atmospheric Radiation Measurement (ARM) Program and held at the ARM Southern Great Plains (SGP) Climate Research Facility. Additional support was provided by the National Aeronautics and Space Administration and the United States Department of Agriculture. A multiple scale observation approach was used during CLASIC. Large scale forcing was quantified using enhanced radiosonde observations within the SGP site in conjunction with the National Oceanic and Atmospheric Administration

  15. Land surface phenological responses to land use and climate variation in a changing Central Asia

    NASA Astrophysics Data System (ADS)

    Kariyeva, Jahan

    During the last few decades Central Asia has experienced widespread changes in land cover and land use following the socio-economic and institutional transformations of the region catalyzed by the USSR collapse in 1991. The decade-long drought events and steadily increasing temperature regimes in the region came on top of these institutional transformations, affecting the long term and landscape scale vegetation responses. This research is based on the need to better understand the potential ecological and policy implications of climate variation and land use practices in the contexts of landscape-scale changes dynamics and variability patterns of land surface phenology responses in Central Asia. The land surface phenology responses -- the spatio-temporal dynamics of terrestrial vegetation derived from the remotely sensed data -- provide measurements linked to the timing of vegetation growth cycles (e.g., start of growing season) and total vegetation productivity over the growing season, which are used as a proxy for the assessment of effects of variations in environmental settings. Local and regional scale assessment of the before and after the USSR collapse vegetation response patterns in the natural and agricultural systems of the Central Asian drylands was conducted to characterize newly emerging links (since 1991) between coupled human and natural systems, e.g., socio-economic and policy drivers of altered land and water use and distribution patterns. Spatio-temporal patterns of bioclimatic responses were examined to determine how phenology is associated with temperature and precipitation in different land use types, including rainfed and irrigated agricultural types. Phenological models were developed to examine relationship between environmental drivers and effect of their altitudinal and latitudinal gradients on the broad-scale vegetation response patterns in non-cropland ecosystems of the desert, steppe, and mountainous regional landscapes of Central Asia

  16. Algorithm for remote sensing of land surface temperature

    NASA Astrophysics Data System (ADS)

    AlSultan, Sultan; Lim, H. S.; MatJafri, M. Z.; Abdullah, K.

    2008-10-01

    This study employs the developed algorithm for retrieving land surface temperature (LST) from Landsat TM over Saudi Arabia. The algorithm is a mono window algorithm because the Landsat TM has only one thermal band between wavelengths of 10.44-12.42 μm. The proposed algorithm included three parameters, brightness temperature, surface emissivity and incoming solar radiation in the algorithm regression analysis. The LST estimated by the proposed developed algorithm and the LST values produced using ATCORT2_T in the PCI Geomatica 9.1 image processing software were compared. The mono window algorithm produced high accuracy LST values using Landsat TM data.

  17. Land-surface atmosphere coupling in an earth system model

    NASA Astrophysics Data System (ADS)

    de Vrese, Philipp; Hagemann, Stefan

    2014-05-01

    The interaction between the atmosphere and the strongly heterogeneous land surface is one of the central scientific topics within Earth system sciences and especially climate research. Many processes, such as vegetation dynamics and the development of spatial patterns in the Subtropics and permafrost regions, take place on scales much below the scale of model resolution. Thus, it is an important scientific challenge to consider the influence of sub-scale heterogeneity on the vertical near-surface fluxes of energy and water. Most climate models do not take into account the actual scale of surface heterogeneities. When coupling a heterogeneous surface to the atmosphere often coupling methods are employed, which include the underlying assumption that the horizontal extent of the individual heterogeneity is so small that the turbulent vertical fluxes stemming from the different surface heterogeneities within one grid-box have mixed horizontally below the lowest model level of the atmosphere. This assumption allows a comparatively simple land-surface-atmosphere coupling with a horizontally homogeneous state of the atmosphere, but it may also be the source of significant errors. In order to access the extent of error introduced we designed an experiment in which the results of three different coupling schemes were compared. The first one is a parameter-aggregation scheme, the second a flux-aggregation scheme based on the assumption of a horizontally homogeneous atmosphere on the lowest atmospheric model level and the third one is a coupling scheme which allows, up to a given height, for the atmosphere to be horizontally heterogeneous within a grid-box. These coupling methods were implemented in the land-surface model JSBACH which was then coupled to the general circulation model ECHAM6, both part of the Max Planck Institute for Meteorology's earth system model MPI-ESM. In a first step sensitivity studies are being carried out to gain process understanding and to

  18. Land surface temperature measurements from EOS MODIS data

    NASA Technical Reports Server (NTRS)

    Wan, Zhengming

    1994-01-01

    A generalized split-window method for retrieving land-surface temperature (LST) from AVHRR and MODIS data has been developed. Accurate radiative transfer simulations show that the coefficients in the split-window algorithm for LST must depend on the viewing angle, if we are to achieve a LST accuracy of about 1 K for the whole scan swath range (+/-55.4 deg and +/-55 deg from nadir for AVHRR and MODIS, respectively) and for the ranges of surface temperature and atmospheric conditions over land, which are much wider than those over oceans. We obtain these coefficients from regression analysis of radiative transfer simulations, and we analyze sensitivity and error by using results from systematic radiative transfer simulations over wide ranges of surface temperatures and emissivities, and atmospheric water vapor abundance and temperatures. Simulations indicated that as atmospheric column water vapor increases and viewing angle is larger than 45 deg it is necessary to optimize the split-window method by separating the ranges of the atmospheric column water vapor and lower boundary temperature, and the surface temperature into tractable sub-ranges. The atmospheric lower boundary temperature and (vertical) column water vapor values retrieved from HIRS/2 or MODIS atmospheric sounding channels can be used to determine the range where the optimum coefficients of the split-window method are given. This new LST algorithm not only retrieves LST more accurately but also is less sensitive than viewing-angle independent LST algorithms to the uncertainty in the band emissivities of the land-surface in the split-window and to the instrument noise.

  19. Advanced Potential Energy Surfaces for Molecular Simulation.

    PubMed

    Albaugh, Alex; Boateng, Henry A; Bradshaw, Richard T; Demerdash, Omar N; Dziedzic, Jacek; Mao, Yuezhi; Margul, Daniel T; Swails, Jason; Zeng, Qiao; Case, David A; Eastman, Peter; Wang, Lee-Ping; Essex, Jonathan W; Head-Gordon, Martin; Pande, Vijay S; Ponder, Jay W; Shao, Yihan; Skylaris, Chris-Kriton; Todorov, Ilian T; Tuckerman, Mark E; Head-Gordon, Teresa

    2016-09-22

    Advanced potential energy surfaces are defined as theoretical models that explicitly include many-body effects that transcend the standard fixed-charge, pairwise-additive paradigm typically used in molecular simulation. However, several factors relating to their software implementation have precluded their widespread use in condensed-phase simulations: the computational cost of the theoretical models, a paucity of approximate models and algorithmic improvements that can ameliorate their cost, underdeveloped interfaces and limited dissemination in computational code bases that are widely used in the computational chemistry community, and software implementations that have not kept pace with modern high-performance computing (HPC) architectures, such as multicore CPUs and modern graphics processing units (GPUs). In this Feature Article we review recent progress made in these areas, including well-defined polarization approximations and new multipole electrostatic formulations, novel methods for solving the mutual polarization equations and increasing the MD time step, combining linear-scaling electronic structure methods with new QM/MM methods that account for mutual polarization between the two regions, and the greatly improved software deployment of these models and methods onto GPU and CPU hardware platforms. We have now approached an era where multipole-based polarizable force fields can be routinely used to obtain computational results comparable to state-of-the-art density functional theory while reaching sampling statistics that are acceptable when compared to that obtained from simpler fixed partial charge force fields.

  20. RASSOR - Regolith Advanced Surface Systems Operations Robot

    NASA Technical Reports Server (NTRS)

    Gill, Tracy R.; Mueller, Rob

    2015-01-01

    The Regolith Advanced Surface Systems Operations Robot (RASSOR) is a lightweight excavator for mining in reduced gravity. RASSOR addresses the need for a lightweight (<100 kg) robot that is able to overcome excavation reaction forces while operating in reduced gravity environments such as the moon or Mars. A nominal mission would send RASSOR to the moon to operate for five years delivering regolith feedstock to a separate chemical plant, which extracts oxygen from the regolith using H2 reduction methods. RASSOR would make 35 trips of 20 kg loads every 24 hours. With four RASSORs operating at one time, the mission would achieve 10 tonnes of oxygen per year (8 t for rocket propellant and 2 t for life support). Accessing craters in space environments may be extremely hard and harsh due to volatile resources - survival is challenging. New technologies and methods are required. RASSOR is a product of KSC Swamp Works which establishes rapid, innovative and cost effective exploration mission solutions by leveraging partnerships across NASA, industry and academia.

  1. Advanced Potential Energy Surfaces for Molecular Simulation.

    PubMed

    Albaugh, Alex; Boateng, Henry A; Bradshaw, Richard T; Demerdash, Omar N; Dziedzic, Jacek; Mao, Yuezhi; Margul, Daniel T; Swails, Jason; Zeng, Qiao; Case, David A; Eastman, Peter; Wang, Lee-Ping; Essex, Jonathan W; Head-Gordon, Martin; Pande, Vijay S; Ponder, Jay W; Shao, Yihan; Skylaris, Chris-Kriton; Todorov, Ilian T; Tuckerman, Mark E; Head-Gordon, Teresa

    2016-09-22

    Advanced potential energy surfaces are defined as theoretical models that explicitly include many-body effects that transcend the standard fixed-charge, pairwise-additive paradigm typically used in molecular simulation. However, several factors relating to their software implementation have precluded their widespread use in condensed-phase simulations: the computational cost of the theoretical models, a paucity of approximate models and algorithmic improvements that can ameliorate their cost, underdeveloped interfaces and limited dissemination in computational code bases that are widely used in the computational chemistry community, and software implementations that have not kept pace with modern high-performance computing (HPC) architectures, such as multicore CPUs and modern graphics processing units (GPUs). In this Feature Article we review recent progress made in these areas, including well-defined polarization approximations and new multipole electrostatic formulations, novel methods for solving the mutual polarization equations and increasing the MD time step, combining linear-scaling electronic structure methods with new QM/MM methods that account for mutual polarization between the two regions, and the greatly improved software deployment of these models and methods onto GPU and CPU hardware platforms. We have now approached an era where multipole-based polarizable force fields can be routinely used to obtain computational results comparable to state-of-the-art density functional theory while reaching sampling statistics that are acceptable when compared to that obtained from simpler fixed partial charge force fields. PMID:27513316

  2. Surface Landing Site Weather Analysis for NASA's Constellation Program

    NASA Technical Reports Server (NTRS)

    Altino, Karen M.; Burns, K. L.

    2008-01-01

    Weather information is an important asset for NASA's Constellation Program in developing the next generation space transportation system to fly to the International Space Station, the Moon and, eventually, to Mars. Weather conditions can affect vehicle safety and performance during multiple mission phases ranging from pre-launch ground processing of the Ares vehicles to landing and recovery operations, including all potential abort scenarios. Meteorological analysis is art important contributor, not only to the development and verification of system design requirements but also to mission planning and active ground operations. Of particular interest are the surface weather conditions at both nominal and abort landing sites for the manned Orion capsule. Weather parameters such as wind, rain, and fog all play critical roles in the safe landing of the vehicle and subsequent crew and vehicle recovery. The Marshall Space Flight Center (MSFC) Natural Environments Branch has been tasked by the Constellation Program with defining the natural environments at potential landing zones. This paper wiI1 describe the methodology used for data collection and quality control, detail the types of analyses performed, and provide a sample of the results that cab be obtained.

  3. CEOS Land Surface Imaging Constellation Mid-Resolution Optical Guidelines

    NASA Technical Reports Server (NTRS)

    Keyes, Jennifer P.; Killough, B.

    2011-01-01

    The LSI community of users is large and varied. To reach all these users as well as potential instrument contributors this document has been organized by measurement parameters of interest such as Leaf Area Index and Land Surface Temperature. These measurement parameters and the data presented in this document are drawn from multiple sources, listed at the end of the document, although the two primary ones are "The Space-Based Global Observing System in 2010 (GOS-2010)" that was compiled for the World Meteorological Organization (WMO) by Bizzarro Bizzarri, and the CEOS Missions, Instruments, and Measurements online database (CEOS MIM). For each measurement parameter the following topics will be discussed: (1) measurement description, (2) applications, (3) measurement spectral bands, and (4) example instruments and mission information. The description of each measurement parameter starts with a definition and includes a graphic displaying the relationships to four general land surface imaging user communities: vegetation, water, earth, and geo-hazards, since the LSI community of users is large and varied. The vegetation community uses LSI data to assess factors related to topics such as agriculture, forest management, crop type, chlorophyll, vegetation land cover, and leaf or canopy differences. The water community analyzes snow and lake cover, water properties such as clarity, and body of water delineation. The earth community focuses on minerals, soils, and sediments. The geo-hazards community is designed to address and aid in emergencies such as volcanic eruptions, forest fires, and large-scale damaging weather-related events.

  4. Accessing Recent Trend of Land Surface Temperature from Satellite Observations

    NASA Astrophysics Data System (ADS)

    Shen, S.; Leptoukh, G. G.; Romanov, P.

    2011-12-01

    Land surface temperature (LST) is an important element to measure the state of the terrestrial ecosystems and to study the surface energy budgets. In support of the land cover/land use change related international program MAIRS (Monsoon Asia Integrated Regional Study), we have collected the global monthly LST measured by MODIS since the beginning of the missions. The MODIS LST time series have ~11 years of data from Terra since 2000 and ~9 years of data from Aqua since 2002, which makes possible to study the recent climate, such as trend and variability. In this study, monthly climatology from two satellite platforms are calculated and compared. The spatial patterns of LST trends are accessed, focusing on the Asian Monsoon region. Furthermore, the MODIS LST trends are compared with the skin temperature trend from the NASA's atmospheric assimilation model, MERRA (MODERN ERA RETROSPECTIVE-ANALYSIS FOR RESEARCH AND APPLICATIONS), which has longer data record since 1979. The calculated climatology and anomaly of MODIS LST will be integrated into the online visualization system, Giovanni, at NASA GES DISC for easy access and use by scientists and general public.

  5. Evaluation of Ten Methods for Initializing a Land Surface Model

    NASA Technical Reports Server (NTRS)

    Rodell, M.; Houser, P. R.; Berg, A. A.; Famiglietti, J. S.

    2005-01-01

    Land surface models (LSMs) are computer programs, similar to weather and climate prediction models, which simulate the stocks and fluxes of water (including soil moisture, snow, evaporation, and runoff) and energy (including the temperature of and sensible heat released from the soil) after they arrive on the land surface as precipitation and sunlight. It is not currently possible to measure all of the variables of interest everywhere on Earth with sufficient accuracy and space-time resolution. Hence LSMs have been developed to integrate the available observations with our understanding of the physical processes involved, using powerful computers, in order to map these stocks and fluxes as they change in time. The maps are used to improve weather forecasts, support water resources and agricultural applications, and study the Earth"s water cycle and climate variability. NASA"s Global Land Data Assimilation System (GLDAS) project facilitates testing of several different LSMs with a variety of input datasets (e.g., precipitation, plant type).

  6. Accessing Recent Trend of Land Surface Temperature from Satellite Observations

    NASA Technical Reports Server (NTRS)

    Shen, Suhung; Leptoukh, Gregory G.; Romanov, Peter

    2011-01-01

    Land surface temperature (Ts) is an important element to measure the state of terrestrial ecosystems and to study surface energy budgets. In support of the land cover/land use change-related international program MAIRS (Monsoon Asia Integrated Regional Study), we have collected global monthly Ts measured by MODIS since the beginning of the missions. The MODIS Ts time series have approximately 11 years of data from Terra since 2000 and approximately 9 years of data from Aqua since 2002, which makes possible to study the recent climate, such as trend. In this study, monthly climatology from two platforms are calculated and compared with that from AIRS. The spatial patterns of Ts trends are accessed, focusing on the Eurasia region. Furthermore, MODIS Ts trends are compared with those from AIRS and NASA's atmospheric assimilation model, MERRA (Modern Era Retrospective-analysis for Research and Applications). The preliminary results indicate that the recent 8-year Ts trend shows an oscillation-type spatial variation over Eurasia. The pattern is consistent for data from MODIS, AIRS, and MERRA, with the positive center over Eastern Europe, and the negative center over Central Siberia. The calculated climatology and anomaly of MODIS Ts will be integrated into the online visualization system, Giovanni, at NASA GES DISC for easy use by scientists and general public.

  7. Surface Ionization and Soft Landing Techniques in Mass Spectrometry

    SciTech Connect

    Futrell, Jean H.; Laskin, Julia

    2010-04-01

    The advent of soft ionization techniques, notably electrospray and laser desorption ionization methods, has extended mass spectrometric methods to large molecules and molecular complexes. This both greatly expands appli¬cations of mass spectrometry and makes the activation and dissociation of complex ions an integral part of large molecule mass spectrometry. A corollary of the much greater number of internal degrees of freedom and high density of states associated with molecular complexity is that internal energies much higher than the dissociation energies for competing fragmentation processes are required for observable fragmentation in time scales sampled by mass spectrometers. This article describes the kinetics of surface-induced dissociation (SID), a particularly efficient activation method for complex ions. Two very important characteristics of SID are very rapid, sub-picosecond activation and precise control of ion internal energy by varying ion collision energy. The nature of the surface plays an important role in SID, determining both efficiency and mechanism of ion activation. Surface composition and morphology strongly influence the relative importance of competing reactions of SID, ion capture (soft-landing), surface reaction and neutralization. The important features of SID and ion soft-landing are described briefly in this review and more fully in the recommended reading list.

  8. Integrated Display System for Low Visibility Landing and Surface Operations

    NASA Technical Reports Server (NTRS)

    Beskenis, Sharon Otero; Green, David F., Jr.; Hyer, Paul V.; Johnson, Edward J., Jr.

    1998-01-01

    This report summarizes the software products and system architectures developed by Lockheed Martin in support of the Low Visibility Landing and Surface Operations (LVLASO) program at NASA Langley Research Center. It presents an overview of the technical aspects, capabilities, and system integration issues associated with an integrated display system (IDS) that collects, processes and presents information to an aircraft flight crew during all phases of landing, roll-out, turn-off, inbound taxi, outbound taxi and takeoff. Communications hardware, drivers, and software provide continuous real-time data at varying rates and from many different sources to the display programs for presentation on a head-down display (HDD) and/or a head-up display (HUD). An electronic moving map of the airport surface is implemented on the HDD which includes the taxi route assigned by air traffic control, a text messaging system, and surface traffic and runway status information. Typical HUD symbology for navigation and control of the aircraft is augmented to provide aircraft deceleration guidance after touchdown to a pilot selected exit and taxi guidance along the route assigned by ATC. HUD displays include scene-linked symbolic runways, runway exits and taxiways that are conformal with the actual locations on the airport surface. Display formats, system architectures, and the various IDS programs are discussed.

  9. Controls of climatic variability and land cover on land surface hydrology of northern Wisconsin, USA

    NASA Astrophysics Data System (ADS)

    Vano, Julie A.; Foley, Jonathan A.; Kucharik, Christopher J.; Coe, Michael T.

    2008-12-01

    Ecosystem processes are strongly affected by the magnitude, timing, and variability of water flows. As such, our understanding of biogeochemical and ecological processes can be enhanced when our ability to track water flow and storage within ecosystems is improved. We assess how climatic variability and land cover change affect water flow and storage within a temperate forest region of the north central United States (46°N, 89°W). We use a well-validated process-based ecosystem model (IBIS) to investigate evapotranspiration, surface runoff, and drainage rates across a continuum of time scales. We found from 1951 to 2000, climatic variability imposed a large, detectable signal on both annual and seasonal surface water balance that resulted in changes in total runoff that ranged from 30% to 200% of the 50-year average. Conversely, land cover change resulted in subtler, persistent changes (i.e., forest to grassland changed total runoff by 10% annually), which were not detectable from year to year. If, however, changes in land cover persist, within 6 years the cumulative difference from land cover change became slightly more than two standard deviations of annual runoff variability, and within 15 years the accumulated differences were greater than changes between the largest and smallest runoff events within the 50-year period. As a result, in the context of this study, climatic variations typically had a strong effect on the surface water balance in the short term (season or year-to-year variations), but land cover change had influence on water balance over the long-term (6 years and beyond). These changes in hydrology from land cover were detectable as subtle, yet persistent differences that accumulate as changes in magnitude and shifts in seasonal cycles. Through this, we provide a process-based context for understanding the historical causes of water cycle variability, which allows us to better identify the hydrology of this system. Ultimately, this allows for

  10. Subsurface Emission Effects in AMSR-E Measurements: Implications for Land Surface Microwave Emissivity Retrieval

    NASA Technical Reports Server (NTRS)

    Galantowicz, John F.; Moncet, Jean-Luc; Liang, Pan; Lipton, Alan E.; Uymin, Gennady; Prigent, Catherine; Grassotti, Christopher

    2011-01-01

    An analysis of land surface microwave emission time series shows that the characteristic diurnal signature associated with subsurface emission in sandy deserts carry over to arid and semi-arid region worldwide. Prior work found that diurnal variation of Special Sensor Microwave/Imager (SSM/I) brightness temperatures in deserts was small relative to International Satellite Cloud Climatology Project land surface temperature (LST) variation and that the difference varied with surface type and was largest in sand sea regions. Here we find more widespread subsurface emission effects in Advanced Microwave Scanning Radiometer-EOS (AMSR-E) measurements. The AMSR-E orbit has equator crossing times near 01:30 and 13 :30 local time, resulting in sampling when near-surface temperature gradients are likely to be large and amplifying the influence of emission depth on effective emitting temperature relative to other factors. AMSR-E measurements are also temporally coincident with Moderate Resolution Imaging Spectroradiometer (MODIS) LST measurements, eliminating time lag as a source of LST uncertainty and reducing LST errors due to undetected clouds. This paper presents monthly global emissivity and emission depth index retrievals for 2003 at 11, 19, 37, and 89 GHz from AMSR-E, MODIS, and SSM/I time series data. Retrieval model fit error, stability, self-consistency, and land surface modeling results provide evidence for the validity of the subsurface emission hypothesis and the retrieval approach. An analysis of emission depth index, emissivity, precipitation, and vegetation index seasonal trends in northern and southern Africa suggests that changes in the emission depth index may be tied to changes in land surface moisture and vegetation conditions

  11. The effect of roughness in simultaneously retrieval of land surface parameters

    NASA Astrophysics Data System (ADS)

    Moradizadeh, Mina; Saradjian, Mohammad R.

    2016-08-01

    Using remotely-sensed data, various soil moisture estimation models have been developed for bare soil areas. Previous studies have shown that the brightness temperature (BT) measured by passive microwave sensors were affected by characteristics of the land surface parameters including soil moisture, vegetation cover and soil roughness. Therefore knowledge of vegetation cover and soil roughness is important for obtaining frequent and global estimations of land surface parameters especially soil moisture. In this study, a model called Simultaneous Land Parameters Retrieval Model (SLPRM) that is an iterative least-squares minimization method is proposed. The algorithm estimates surface soil moisture, land surface temperature and canopy temperature simultaneously in vegetated areas using AMSR-E (Advance Microwave Scanning Radiometer-EOS) brightness temperature data. The simultaneous estimations of the three parameters are based on a multi-parameter inversion algorithm which includes model construction, calibration and validation using observations carried out for the SMEX03 (Soil Moisture Experiment, 2003) region in the South and North of Oklahoma. Roughness parameter has also been included in the algorithm to increase the soil parameters retrieval accuracy. Unlike other methods, the SLPRM method works efficiently in all land covers types. The study focuses on soil parameters estimation by comparing three different scenarios with the inclusion of roughness data and selects the most appropriate one. The difference between the resulted accuracies of scenarios is due to the roughness calculation approach. The analysis on the retrieval model shows a meaningful and acceptable accuracy on soil moisture estimation according to the three scenarios. The SLPRM method has shown better performance when the SAR (Synthetic Aperture RADAR) data are used for roughness calculation.

  12. 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.

  13. Surface-material maps of Viking landing sites on Mars

    NASA Astrophysics Data System (ADS)

    Moore, H. J.; Keller, J. M.

    1991-06-01

    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.

  14. Towards an improved land surface scheme for prairie landscapes

    NASA Astrophysics Data System (ADS)

    Mekonnen, M. A.; Wheater, H. S.; Ireson, A. M.; Spence, C.; Davison, B.; Pietroniro, A.

    2014-04-01

    The prairie region of Canada and the United States is characterized by millions of small depressions of glacial origin called prairie potholes. The transfer of surface runoff in this landscape is mainly through a “fill and spill” mechanism among neighboring potholes. While non-contributing areas, that is small internally drained basins, are common on this landscape, during wet periods these areas can become hydrologically connected to larger regional drainage systems. Accurate prediction of prairie surface runoff generation and streamflow thus requires realistic representation of the dynamic threshold-mediated nature of these contributing areas. This paper presents a new prairie surface runoff generation algorithm for land surface schemes and large scale hydrological models that conceptualizes a hydrologic unit as a combination of variable and interacting storage elements. The proposed surface runoff generation algorithm uses a probability density function to represent the spatial variation of pothole storages and assumes a unique relationship between storage and the fractional contributing area for runoff (and hence amount of direct runoff generated) within a grid cell. In this paper the parameters that define this relationship are obtained by calibration against streamflow. The model was compared to an existing hydrology-land surface scheme (HLSS) applied to a typical Canadian prairie catchment, the Assiniboine River. The existing configuration is based on the Canadian Land Surface Scheme (CLASS) and WATROF (a physically-based overland and interflow scheme). The new configuration consists of CLASS coupled with the new PDMROF model. Results showed that the proposed surface runoff generation algorithm performed better at simulating streamflow, and appears to capture the dynamic nature of contributing areas in an effective and parsimonious manner. A pilot evaluation based on 1 m LiDAR data from a small (10 km2) experimental area suggests that the shape of the

  15. Land Surface Phenology from MODIS: Characterization of the Collection 5 Global Land Cover Dynamics Product

    NASA Technical Reports Server (NTRS)

    Ganguly, Sangram; Friedl, Mark A.; Tan, Bin; Zhang, Xiaoyang; Verma, Manish

    2010-01-01

    Information related to land surface phenology is important for a variety of applications. For example, phenology is widely used as a diagnostic of ecosystem response to global change. In addition, phenology influences seasonal scale fluxes of water, energy, and carbon between the land surface and atmosphere. Increasingly, the importance of phenology for studies of habitat and biodiversity is also being recognized. While many data sets related to plant phenology have been collected at specific sites or in networks focused on individual plants or plant species, remote sensing provides the only way to observe and monitor phenology over large scales and at regular intervals. The MODIS Global Land Cover Dynamics Product was developed to support investigations that require regional to global scale information related to spatiotemporal dynamics in land surface phenology. Here we describe the Collection 5 version of this product, which represents a substantial refinement relative to the Collection 4 product. This new version provides information related to land surface phenology at higher spatial resolution than Collection 4 (500-m vs. 1-km), and is based on 8-day instead of 16-day input data. The paper presents a brief overview of the algorithm, followed by an assessment of the product. To this end, we present (1) a comparison of results from Collection 5 versus Collection 4 for selected MODIS tiles that span a range of climate and ecological conditions, (2) a characterization of interannual variation in Collections 4 and 5 data for North America from 2001 to 2006, and (3) a comparison of Collection 5 results against ground observations for two forest sites in the northeastern United States. Results show that the Collection 5 product is qualitatively similar to Collection 4. However, Collection 5 has fewer missing values outside of regions with persistent cloud cover and atmospheric aerosols. Interannual variability in Collection 5 is consistent with expected ranges of

  16. Linkages between Land Surface Phenology Metrics and Natural and Anthropogenic Events in Drylands (Invited)

    NASA Astrophysics Data System (ADS)

    de Beurs, K.; Brown, M. E.; Ahram, A.; Walker, J.; Henebry, G. M.

    2013-12-01

    Tracking vegetation dynamics across landscapes using remote sensing, or 'land surface phenology,' is a key mechanism that allows us to understand ecosystem changes. Land surface phenology models rely on vegetation information from remote sensing, such as the datasets derived from the Advanced Very High Resolution Radiometer (AVHRR), the newer MODIS sensors on Aqua and Terra, and sometimes the higher spatial resolution Landsat data. Vegetation index data can aid in the assessment of variables such as the start of season, growing season length and overall growing season productivity. In this talk we use Landsat, MODIS and AVHRR data and derive growing season metrics based on land surface phenology models that couple vegetation indices with satellite derived accumulated growing degreeday and evapotranspiration estimates. We calculate the timing and the height of the peak of the growing season and discuss the linkage of these land surface phenology metrics with natural and anthropogenic changes on the ground in dryland ecosystems. First we will discuss how the land surface phenology metrics link with annual and interannual price fluctuations in 229 markets distributed over Africa. Our results show that there is a significant correlation between the peak height of the growing season and price increases for markets in countries such as Nigeria, Somalia and Niger. We then demonstrate how land surface phenology metrics can improve models of post-conflict resolution in global drylands. We link the Uppsala Conflict Data Program's dataset of political, economic and social factors involved in civil war termination with an NDVI derived phenology metric and the Palmer Drought Severity Index (PDSI). An analysis of 89 individual conflicts in 42 dryland countries (totaling 892 individual country-years of data between 1982 and 2005) revealed that, even accounting for economic and political factors, countries that have higher NDVI growth following conflict have a lower risk of

  17. Interdependencies of Arctic land surface processes: A uniquely sensitive environment

    NASA Astrophysics Data System (ADS)

    Bowling, L. C.

    2007-12-01

    The circumpolar arctic drainage basin is composed of several distinct ecoregions including steppe grassland and cropland, boreal forest and tundra. Land surface hydrology throughout this diverse region shares several unique features such as dramatic seasonal runoff differences controlled by snowmelt and ice break-up; the storage of significant portions of annual precipitation as snow and in lakes and wetlands; and the effects of ephemeral and permanently frozen soils. These arctic land processes are delicately balanced with the climate and are therefore important indicators of change. The litany of recently-detected changes in the Arctic includes changes in snow precipitation, trends and seasonal shifts in river discharge, increases and decreases in the extent of surface water, and warming soil temperatures. Although not unique to the arctic, increasing anthropogenic pressures represent an additional element of change in the form of resource extraction, fire threat and reservoir construction. The interdependence of the physical, biological and social systems mean that changes in primary indicators have large implications for land cover, animal populations and the regional carbon balance, all of which have the potential to feed back and induce further change. In fact, the complex relationships between the hydrological processes that make the Artic unique also render observed historical change difficult to interpret and predict, leading to conflicting explanations. For example, a decrease in snow accumulation may provide less insulation to the underlying soil resulting in greater frost development and increased spring runoff. Similarly, melting permafrost and ground ice may lead to ground subsidence and increased surface saturation and methane production, while more complete thaw may enhance drainage and result in drier soil conditions. The threshold nature of phase change around the freezing point makes the system especially sensitive to change. In addition, spatial

  18. Surface chemical deposition of advanced electronic materials

    NASA Astrophysics Data System (ADS)

    Bjelkevig, Cameron

    The focus of this work was to examine the direct plating of Cu on Ru diffusion barriers for use in interconnect technology and the substrate mediated growth of graphene on boron nitride for use in advanced electronic applications. The electrodeposition of Cu on Ru(0001) and polycrystalline substrates (with and without pretreatment in an iodine containing solution) has been studied by cyclic voltammetry (CV), current--time transient measurements (CTT), in situ electrochemical atomic force microscopy (EC-AFM), and X-ray photoelectron spectroscopy (XPS). The EC-AFM data show that at potentials near the OPD/UPD threshold, Cu crystallites exhibit pronounced growth anisotropy, with lateral dimensions greatly exceeding vertical dimensions. XPS measurements confirmed the presence and stability of adsorbed I on the Ru surface following pre-treatment in a KI/H2SO4 solution and following polarization to at least -200 mV vs. Ag/AgCl. CV data of samples pre-reduced in I-containing electrolyte exhibited a narrow Cu deposition peak in the overpotential region and a UPD peak. The kinetics of the electrodeposited Cu films was investigated by CTT measurements and applied to theoretical models of nucleation. The data indicated that a protective I adlayer may be deposited on an airexposed Ru electrode as the oxide surface is electrochemically reduced, and that this layer will inhibit reformation of an oxide during the Cu electroplating process. A novel method for epitaxial graphene growth directly on a dielectric substrate of systematically variable thickness was studied. Mono/multilayers of BN(111) were grown on Ru(0001) by atomic layer deposition (ALD), exhibiting a flat (non-nanomesh) R30(✓3x✓3) structure. BN(111) was used as a template for growth of graphene by chemical vapor deposition (CVD) of C2H4 at 1000 K. Characterization by LEED, Auger, STM/STS and Raman indicate the graphene is in registry with the BN substrate, and exhibits a HOPG-like 0 eV bandgap density

  19. Physically plausible prescription of land surface model soil moisture

    NASA Astrophysics Data System (ADS)

    Hauser, Mathias; Orth, René; Thiery, Wim; Seneviratne, Sonia

    2016-04-01

    Land surface hydrology is an important control of surface weather and climate, especially under extreme dry or wet conditions where it can amplify heat waves or floods, respectively. Prescribing soil moisture in land surface models is a valuable technique to investigate this link between hydrology and climate. It has been used for example to assess the influence of soil moisture on temperature variability, mean and extremes (Seneviratne et al. 2006, 2013, Lorenz et al., 2015). However, perturbing the soil moisture content artificially can lead to a violation of the energy and water balances. Here we present a new method for prescribing soil moisture which ensures water and energy balance closure by using only water from runoff and a reservoir term. If water is available, the method prevents soil moisture decrease below climatological values. Results from simulations with the Community Land Model (CLM) indicate that our new method allows to avoid soil moisture deficits in many regions of the world. We show the influence of the irrigation-supported soil moisture content on mean and extreme temperatures and contrast our findings with that of earlier studies. Additionally, we will assess how long into the 21st century the new method will be able to maintain present-day climatological soil moisture levels for different regions. Lorenz, R., Argüeso, D., Donat, M.G., Pitman, A.J., den Hurk, B.V., Berg, A., Lawrence, D.M., Chéruy, F., Ducharne, A., Hagemann, S. and Meier, A., 2015. Influence of land-atmosphere feedbacks on temperature and precipitation extremes in the GLACE-CMIP5 ensemble. Journal of Geophysical Research: Atmospheres. Seneviratne, S.I., Lüthi, D., Litschi, M. and Schär, C., 2006. Land-atmosphere coupling and climate change in Europe. Nature, 443(7108), pp.205-209. Seneviratne, S.I., Wilhelm, M., Stanelle, T., Hurk, B., Hagemann, S., Berg, A., Cheruy, F., Higgins, M.E., Meier, A., Brovkin, V. and Claussen, M., 2013. Impact of soil moisture

  20. The role of GMES / Sentinels in Land-Surface Earth System Science

    NASA Astrophysics Data System (ADS)

    Moreno, J.

    2009-04-01

    A general trend in the current status of representation of Land Surface schemes into Earth System models is driven by the parameterisation of "cycles" instead of individual processes. Particular emphasis is made to account for couplings among the individual cycles, as between the carbon and water cycles. Moreover, the current tendency is to use the measured data -time series in most cases- together with models, in a data assimilation scenario where inputs from multiple sources are integrated. Such approach is more and more necessary as land models tend to be more complex, and particularly due to the fact that land surface variability is not just driven by physical and chemical processes, but intricate biological processes also altered by anthropogenic influences. Human influences in the land system (land use changes, urban development, etc.) and the impacts of natural disasters are becoming also part of land models, but critical data in high spatial and temporal resolutions are needed to properly model such processes. Until now, problems with data availability, data inconsistency and lack of adequate temporal sampling have limited the potential usefulness of such observations in modelling land surface processes. The availability of the GMES / Sentinel series of satellites represents a quite unique opportunity for consolidation of current tendencies and development of new science based on the new type of data that soon will become available. The usefulness of the different Sentinel missions for Land science has been recognised. Although the Sentinel satellite series were primarily designed to provide observations for operational services and routine applications, there is a growing interest in the scientific community towards the usage of Sentinel data for more advanced and innovative science. Moreover, the availability of consistent time series covering a period of over 20 years opens possibilities never explored before, such as systematic data assimilation

  1. Daytime sensible heat flux estimation over heterogeneous surfaces using multitemporal land-surface temperature observations

    NASA Astrophysics Data System (ADS)

    Castellví, F.; Cammalleri, C.; Ciraolo, G.; Maltese, A.; Rossi, F.

    2016-05-01

    Equations based on surface renewal (SR) analysis to estimate the sensible heat flux (H) require as input the mean ramp amplitude and period observed in the ramp-like pattern of the air temperature measured at high frequency. A SR-based method to estimate sensible heat flux (HSR-LST) requiring only low-frequency measurements of the air temperature, horizontal mean wind speed, and land-surface temperature as input was derived and tested under unstable conditions over a heterogeneous canopy (olive grove). HSR-LST assumes that the mean ramp amplitude can be inferred from the difference between land-surface temperature and mean air temperature through a linear relationship and that the ramp frequency is related to a wind shear scale characteristic of the canopy flow. The land-surface temperature was retrieved by integrating in situ sensing measures of thermal infrared energy emitted by the surface. The performance of HSR-LST was analyzed against flux tower measurements collected at two heights (close to and well above the canopy top). Crucial parameters involved in HSR-LST, which define the above mentioned linear relationship, were explained using the canopy height and the land surface temperature observed at sunrise and sunset. Although the olive grove can behave as either an isothermal or anisothermal surface, HSR-LST performed close to H measured using the eddy covariance and the Bowen ratio energy balance methods. Root mean square differences between HSR-LST and measured H were of about 55 W m-2. Thus, by using multitemporal thermal acquisitions, HSR-LST appears to bypass inconsistency between land surface temperature and the mean aerodynamic temperature. The one-source bulk transfer formulation for estimating H performed reliable after calibration against the eddy covariance method. After calibration, the latter performed similar to the proposed SR-LST method.

  2. 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.

  3. Development of advanced entry, descent, and landing technologies for future Mars Missions

    NASA Technical Reports Server (NTRS)

    Chu, Cheng-Chih (Chester)

    2006-01-01

    Future Mars missions may need the capability to land much closer to a desired target and/or advanced methods of detecting, avoiding, or tolerating landing hazards. Therefore, technologies that enable 'pinpoint landing' (within tens of meters to 1 km of a target site) will be crucial to meet future mission requirements. As part of NASA Research Announcement, NRA 03-OSS-01, NASA solicited proposals for technology development needs of missions to be launched to Mars during or after the 2009 launch opportunity. Six technology areas were identified as of high priority including advanced entry, descent, and landing (EDL) technologies. In May 2004, 11 proposals with PIs from universities, industries, and NASA centers, were awarded in the area of advanced EDL by NASA for further study and development. This paper presents an overview of these developing technologies.

  4. The impact of land and sea surface variations on the Delaware sea breeze at local scales

    NASA Astrophysics Data System (ADS)

    Hughes, Christopher P.

    -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

  5. Quantifying and relating land-surface and subsurface variability in permafrost environments using lidar and surface geophsical datasets

    SciTech Connect

    Hubbard, Susan S; Gangodagmage, C; Dafflon, B; Wainwright, H; Peterson, J; Gusmeroli, A; Ulrich, Craig; Wu, Yuxin; Wilson, Cathy; Rowland, J; Tweedie, Craig; Wullschleger, Stan D

    2013-01-01

    The complexity of permafrost dynamics and its critical impact on climate feedbacks warrant continued development of advanced high-latitude terrestrial ecosystem characterization and monitoring approaches. In this study, we explore the value of remote sensing and surface geophysical data for characterizing land surface and subsurface properties and their linkages in an Alaskan Coastal Plain ecosystem. We base our study on data collected at the end of the 2011 growing season in the Barrow Environmental Observatory, where a nested suite of measurements were collected within a polygon-dominated region including: surface ground penetrating radar, electromagnetic, and electrical resistance tomography data; thaw depth, soil temperature and moisture content, soil texture, soil carbon and nitrogen content, and major and trace cations. Previously-collected lidar data were also available for the study. Analysis of the datasets, individually and in combination, revealed the utility of the methods for characterizing critical land-surface and subsurface properties and associated spatial zonation. Lidar analysis was performed to extract geomorphic metrics (such as slope, curvature, and directed distance of polygons), which potentially indicate drainage potential and permafrost deformation state. Cluster analysis of these lidar-obtained attributes suggested that the land surface can be grouped into three spatially coherent zones, each having a dominant geomorphic expression including: a high centered polygon zone, a low centered polygon zone and a transitional zone. Comparison of the geophysical attributes from radar, electrical resistance tomography, and electromagnetic data with point measurements suggests that the surface geophysical data can provide very high-resolution information about subsurface properties that affect ecosystem feedbacks to climate, such as thaw depth and moisture content. Cluster analysis suggested that the geophysical attributes also varied spatially in a

  6. The influence of global sea surface temperature variability on the large-scale land surface temperature

    NASA Astrophysics Data System (ADS)

    Tyrrell, Nicholas L.; Dommenget, Dietmar; Frauen, Claudia; Wales, Scott; Rezny, Mike

    2015-04-01

    In global warming scenarios, global land surface temperatures () warm with greater amplitude than sea surface temperatures (SSTs), leading to a land/sea warming contrast even in equilibrium. Similarly, the interannual variability of is larger than the covariant interannual SST variability, leading to a land/sea contrast in natural variability. This work investigates the land/sea contrast in natural variability based on global observations, coupled general circulation model simulations and idealised atmospheric general circulation model simulations with different SST forcings. The land/sea temperature contrast in interannual variability is found to exist in observations and models to a varying extent in global, tropical and extra-tropical bands. There is agreement between models and observations in the tropics but not the extra-tropics. Causality in the land-sea relationship is explored with modelling experiments forced with prescribed SSTs, where an amplification of the imposed SST variability is seen over land. The amplification of to tropical SST anomalies is due to the enhanced upper level atmospheric warming that corresponds with tropical moist convection over oceans leading to upper level temperature variations that are larger in amplitude than the source SST anomalies. This mechanism is similar to that proposed for explaining the equilibrium global warming land/sea warming contrast. The link of the to the dominant mode of tropical and global interannual climate variability, the El Niño Southern Oscillation (ENSO), is found to be an indirect and delayed connection. ENSO SST variability affects the oceans outside the tropical Pacific, which in turn leads to a further, amplified and delayed response of.

  7. A conceptual design of PRISM-2 for Advanced Land Observing Satellite-3(ALOS-3)

    NASA Astrophysics Data System (ADS)

    Imai, Hiroko; Katayama, Haruyoshi; Sagisaka, Masakazu; Hatooka, Yasushi; Suzuki, Shinichi; Osawa, Yuji; Takahashi, Masuo; Tadono, Takeo

    2012-09-01

    The Japan Aerospace Exploration Agency (JAXA) is planning a satellite system including Advanced Land Observing Satellites 2 and 3 (ALOS-2 and ALOS-3) for the ALOS follow-on program. ALOS-3 will carry the optical sensor named "PRISM-2" and extend the capabilities of earlier ALOS missions. PRISM-2 will be able to collect high-resolution (0.8m) and wide-swath (50 km) imagery with high geo-location accuracy, as well as provide precise digital surface models (DSMs) using stereo pair images acquired by two telescopes. These capabilities are ideal for obtaining large-scale geographical information such as elevation and land cover-maps for use in many research areas and practical applications, including disaster management support. JAXA has conducted a phase A study of the ALOS-3 spacecraft and PRISM-2, and is now working on prototype models of key components of PRISM-2's telescope, focal plane, and data compressor. This paper introduces a conceptual design for PRISM-2 and the ALOS-3 system.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  9. Land Surface Modeling Applications for Famine Early Warning

    NASA Astrophysics Data System (ADS)

    McNally, A.; Verdin, J. P.; Peters-Lidard, C. D.; Arsenault, K. R.; Wang, S.; Kumar, S.; Shukla, S.; Funk, C. C.; Pervez, M. S.; Fall, G. M.; Karsten, L. R.

    2015-12-01

    AGU 2015 Fall Meeting Session ID#: 7598 Remote Sensing Applications for Water Resources Management Land Surface Modeling Applications for Famine Early Warning James Verdin, USGS EROS Christa Peters-Lidard, NASA GSFC Amy McNally, NASA GSFC, UMD/ESSIC Kristi Arsenault, NASA GSFC, SAIC Shugong Wang, NASA GSFC, SAIC Sujay Kumar, NASA GSFC, SAIC Shrad Shukla, UCSB Chris Funk, USGS EROS Greg Fall, NOAA Logan Karsten, NOAA, UCAR Famine early warning has traditionally required close monitoring of agro-climatological conditions, putting them in historical context, and projecting them forward to anticipate end-of-season outcomes. In recent years, it has become necessary to factor in the effects of a changing climate as well. There has also been a growing appreciation of the linkage between food security and water availability. In 2009, Famine Early Warning Systems Network (FEWS NET) science partners began developing land surface modeling (LSM) applications to address these needs. With support from the NASA Applied Sciences Program, an instance of the Land Information System (LIS) was developed to specifically support FEWS NET. A simple crop water balance model (GeoWRSI) traditionally used by FEWS NET took its place alongside the Noah land surface model and the latest version of the Variable Infiltration Capacity (VIC) model, and LIS data readers were developed for FEWS NET precipitation forcings (NOAA's RFE and USGS/UCSB's CHIRPS). The resulting system was successfully used to monitor and project soil moisture conditions in the Horn of Africa, foretelling poor crop outcomes in the OND 2013 and MAM 2014 seasons. In parallel, NOAA created another instance of LIS to monitor snow water resources in Afghanistan, which are an early indicator of water availability for irrigation and crop production. These successes have been followed by investment in LSM implementations to track and project water availability in Sub-Saharan Africa and Yemen, work that is now underway. Adoption of

  10. Impact of Calibrated Land Surface Model Parameters on the Accuracy and Uncertainty of Land-Atmosphere Coupling in WRF Simulations

    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 temperature 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 (LIS-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.

  11. Land use and surface process domains on alpine hillslopes

    NASA Astrophysics Data System (ADS)

    Kuhn, Nikolaus J.; Caviezel, Chatrina; Hunziker, Matthias

    2015-04-01

    Shrubs and trees are generally considered to protect hillslopes from erosion. As a consequence, shrub encroachment on mountain pastures after abandoning grazing is not considered a threat to soils. However, the abandonment of mown or grazed grasslands causes a shift in vegetation composition and thus a change in landscape ecology and geomorphology. On many alpine slopes, current changes in land use and vegetation cover are accompanied by climate change, potentially generating a new geomorphic regime. Most of the debate focuses on the effect of land abandonment on water erosion rates. Generally, an established perennial vegetation cover improves the mechanical anchoring of the soil and the regulation of the soil water budget, including runoff generation and erosion. However, changing vegetation composition affects many other above- and below-ground properties like root density, -diversity and -geometry, soil structure, pore volume and acidity. Each combination of these properties can lead to a distinct scenario of dominating surface processes, often not reflected by common erosion risk assessment procedures. The study of soil properties along a chronosequence of green alder (alnusviridis) encroachment on the Unteralptal in central Switzerland reveals that shrub encroachment changes soil and vegetation properties towards an increase of resistance to run-off related erosion processes, but a decrease of slope stability against shallow landslides. The latter are a particular threat because of the currently increasing frequency of slide-triggering high magnitude rainfalls. The potential change of process domain on alpine pastures highlights the need for a careful use of erosion models when assessing future land use and climate scenarios. In mountains, but also other intensively managed agricultural landscapes, risk assessment without the appropriate reflection on the shifting relevance of surface processes carries the risk of missing future threats to environmental

  12. Simulation of land-atmosphere gaseous exchange using a coupled land surface-biogeochemical model

    NASA Astrophysics Data System (ADS)

    Gu, C.; Riley, W. J.; Perez, T. J.; Pan, L.

    2009-12-01

    It is important to develop and evaluate biogeochemical models that on the one hand represent vegetation and soil dynamics and on the other hand provide energy and water fluxes in a temporal resolution suitable for biogeochemical processes. In this study, we present a consistent coupling between a common land surface model (CLM3.0) and a recently developed biogeochemical model (TOUGHREACT-N). The model TOUGHREACT-N (TR-N) is one of the few process-based models that simulate green house gases fluxes by using an implicit scheme to solve the diffusion equations governing soil heat and water fluxes. By coupling with CLM3.0, we have significantly improved TR-N by including realistic representations of surface water, energy, and momentum exchanges, through the use of improved formulations for soil evaporation, plant transpiration, vegetation growth, and plant nitrogen uptake embedded in CLM3.0. The coupled CLMTR-N model is a first step for a full coupling of land surface and biogeochemical processes. The model is evaluated with measurements of soil temperature, soil water content, and N2O and N2 gaseous emission data from fallow, corn, and forest sites in Venezuela. The results demonstrate that the CLMTR-N model simulates realistic diurnal variation of soil temperature, soil water content, and N gaseous fluxes. For example, mean differences between predicted and observed midday near-surface soil water content were 8, 11, and 4 % in July, August, and September. The sensitivity of the biogeochemical processes and resulting N emissions to variation in environmental drivers is high, which indicates the need to calculate biogeochemical processes in, at least, two hourly time steps using dynamically updated (rather than daily averaged) soil environmental conditions. The development in CLMTR-N of such a complex representation of processes will allow us to characterize relevant processes and simplifications appropriate for regional to global-scale coupled biogeochemical and

  13. Land Surface Temperature Measurements form EOS MODIS Data

    NASA Technical Reports Server (NTRS)

    Wan, Zhengming

    1996-01-01

    We have developed a physics-based land-surface temperature (LST) algorithm for simultaneously retrieving surface band-averaged emissivities and temperatures from day/night pairs of MODIS (Moderate Resolution Imaging Spectroradiometer) data in seven thermal infrared bands. The set of 14 nonlinear equations in the algorithm is solved with the statistical regression method and the least-squares fit method. This new LST algorithm was tested with simulated MODIS data for 80 sets of band-averaged emissivities calculated from published spectral data of terrestrial materials in wide ranges of atmospheric and surface temperature conditions. Comprehensive sensitivity and error analysis has been made to evaluate the performance of the new LST algorithm and its dependence on variations in surface emissivity and temperature, upon atmospheric conditions, as well as the noise-equivalent temperature difference (NE(Delta)T) and calibration accuracy specifications of the MODIS instrument. In cases with a systematic calibration error of 0.5%, the standard deviations of errors in retrieved surface daytime and nighttime temperatures fall between 0.4-0.5 K over a wide range of surface temperatures for mid-latitude summer conditions. The standard deviations of errors in retrieved emissivities in bands 31 and 32 (in the 10-12.5 micrometer IR spectral window region) are 0.009, and the maximum error in retrieved LST values falls between 2-3 K. Several issues related to the day/night LST algorithm (uncertainties in the day/night registration and in surface emissivity changes caused by dew occurrence, and the cloud cover) have been investigated. The LST algorithms have been validated with MODIS Airborne Simulator (MAS) dada and ground-based measurement data in two field campaigns conducted in Railroad Valley playa, NV in 1995 and 1996. The MODIS LST version 1 software has been delivered.

  14. Evaluating soil moisture constraints on surface fluxes in land surface models globally

    NASA Astrophysics Data System (ADS)

    Harris, Phil; Gallego-Elvira, Belen; Taylor, Christopher; Folwell, Sonja; Ghent, Darren; Veal, Karen; Hagemann, Stefan

    2016-04-01

    Soil moisture availability exerts a strong control over land evaporation in many regions. However, global climate models (GCMs) disagree on when and where evaporation is limited by soil moisture. Evaluation of the relevant modelled processes has suffered from a lack of reliable, global observations of land evaporation at the GCM grid box scale. Satellite observations of land surface temperature (LST) offer spatially extensive but indirect information about the surface energy partition and, under certain conditions, about soil moisture availability on evaporation. Specifically, as soil moisture decreases during rain-free dry spells, evaporation may become limited leading to increases in LST and sensible heat flux. We use MODIS Terra and Aqua observations of LST at 1 km from 2000 to 2012 to assess changes in the surface energy partition during dry spells lasting 10 days or longer. The clear-sky LST data are aggregated to a global 0.5° grid before being composited as a function dry spell day across many events in a particular region and season. These composites are then used to calculate a Relative Warming Rate (RWR) between the land surface and near-surface air. This RWR can diagnose the typical strength of short term changes in surface heat fluxes and, by extension, changes in soil moisture limitation on evaporation. Offline land surface model (LSM) simulations offer a relatively inexpensive way to evaluate the surface processes of GCMs. They have the benefits that multiple models, and versions of models, can be compared on a common grid and using unbiased forcing. Here, we use the RWR diagnostic to assess global, offline simulations of several LSMs (e.g., JULES and JSBACH) driven by the WATCH Forcing Data-ERA Interim. Both the observed RWR and the LSMs use the same 0.5° grid, which allows the observed clear-sky sampling inherent in the underlying MODIS LST to be applied to the model outputs directly. This approach avoids some of the difficulties in analysing free

  15. An Open and Transparent Databank of Global Land Surface Temperature

    NASA Astrophysics Data System (ADS)

    Rennie, J.; Thorne, P.; Lawrimore, J. H.; Gleason, B.; Menne, M. J.; Williams, C.

    2013-12-01

    The International Surface Temperature Initiative (ISTI) consists of an effort to create an end-to-end process for land surface air temperature analyses. The foundation of this process is the establishment of a global land surface databank. The databank builds upon the groundbreaking efforts of scientists who led efforts to construct global land surface datasets in the 1980's and 1990's. A primary aim of the databank is to improve aspects including data provenance, version control, temporal and spatial coverage, and improved methods for bringing dozens of source data together into an integrated dataset. The databank consists of multiple stages, with each successive stage providing a higher level of processing, quality and integration. Currently more than 50 sources of data have been added to the databank. An automated algorithm has been developed that merges these sources into one complete dataset by removing duplicate station records, identifying two or more station records that can be merged into a single record, and incorporating new and unique stations. The program runs iteratively through all the sources which are ordered based upon criteria established by the ISTI. The highest preferred source, known as the target, runs through all the candidate sources, calculating station comparisons that are acceptable for merging. The process is probabilistic in approach, and the final fate of a candidate station is based upon metadata matching and data equivalence criteria. If there is not enough information, the station is withheld for further investigation. The algorithm has been validated using a pseudo-source of stations with a known time of observation bias, and correct matches have been made nearly 95% of the time. The final product, endorsed and recommended by ISTI, contains over 30,000 stations, however slight changes in the algorithm can perturb results. Subjective decisions, such as the ordering of the sources, or changing metadata and data matching thresholds

  16. The Rhone-Aggregation Land Surface Scheme Intercomparison Project

    NASA Astrophysics Data System (ADS)

    Boone, A. A.; Habets, F.; Noilhan and Working Group, J.

    2002-05-01

    The Rhone-AGGregation (Rhone-AGG) Land Surface Scheme intercomparison project is an initiative within the Global Energy and Water Cycle Experiment (GEWEX) Global Land-Atmosphere System Study (GLASS)/Global Soil Wetness Project (GSWP) panel of the World Climate Research Programme (WCRP). This project makes use of the Rhone modeling system, which was developed in recent years by the French research community in order to study the continental water cycle on a regional scale. Three distinct components comprise this system: an analysis system to determine the near-surface atmospheric forcing, a Land Surface Scheme (LSS) interface and a distributed hydrological model. The coupling between the three components of the system is 1-way. It was created in an attempt to ensure a consistent dialogue between the atmosphere (precipitation, radiative fluxes, state variables) and the hydrological variables (evaporation, soil moisture, runoff, ground water and river flow). The atmospheric data, which have been mapped to an 8 km grid, consist of standard screen level observations at approximately 60 Météo-France weather network sites within the domain, European Centre for Medium-Range Weather Forecasts (ECMWF) analysis, climatological data and total daily precipitation data from over 1500 gauges. The system utilizes high spatial resolution European soil and vegetation databases, but it has been designed such that it is transferable to other regions. The size of the entire Rhone basin (86,996 km 2) is comparable to the area of a typical coarse-resolution Global atmospheric Climate Model (GCM) grid element, so that it is of interest to examine how the simulations from a wide range of LSSs, which are used in GCMs, numerical weather prediction models, mesoscale atmospheric models or hydrological models, are impacted by changing the spatial resolution over the domain from 8 km to approximately 69 km (1 degree). The main issues addressed by the Rhone-AGG project are how various state of

  17. Improved in-situ methods for determining land surface emissivity

    NASA Astrophysics Data System (ADS)

    Göttsche, Frank; Olesen, Folke; Hulley, Glynn

    2014-05-01

    The accurate validation of LST satellite products, such as the operational LST retrieved by the Land Surface Analysis - Satellite Application Facility (LSA-SAF), requires accurate knowledge of emissivity for the areas observed by the ground radiometers as well as for the area observed by the satellite sensor. Especially over arid regions, the relatively high uncertainty in land surface emissivity (LSE) limits the accuracy with which land surface temperature (LST) can be retrieved from thermal infrared (TIR) radiance measurements. LSE uncertainty affects LST obtained from satellite measurements and in-situ radiance measurements alike. Furthermore, direct comparisons between satellite sensors and ground based sensors are complicated by spatial scale mismatch: ground radiometers usually observe some 10 m2, whereas satellite sensors typically observe between 1 km2 and 100 km2. Therefore, validation sites have to be carefully selected and need to be characterised on the scale of the ground radiometer as well as on the scale of the satellite pixel. The permanent stations near Gobabeb (Namibia; hyper-arid desert climate) and Dahra (Senegal; hot-arid steppe-prairie climate) are two of KIT's four dedicated LST validation stations. Gobabeb station is located on vast and flat gravel plains (several 100 km2), which are mainly covered by coarse gravel, sand, and desiccated grass. The gravel plains are highly homogeneous in space and time, which makes them ideal for validating a broad range of satellite-derived products. Dahra station is located in so called 'tiger bush' and is covered by strongly seasonal grass (95%) and sparse, evergreen trees (dominantly acacia trees) with a background of reddish sand. The strong seasonality is caused by a pronounced rainy season, during which LST retrieval is highly challenging. Outside the rainy season, both sites have relatively large fractions of bare ground and desiccated vegetation: therefore, they are particularly prone to be

  18. Human Mars Landing Site and Impacts on Mars Surface Operations

    NASA Technical Reports Server (NTRS)

    Bussey, Ben; Hoffman, Stephen J.

    2016-01-01

    This paper describes NASA's initial steps for identifying and evaluating candidate Exploration Zones (EZs) and Regions of Interests (ROIs) for the first human crews that will explore the surface of Mars. NASA's current effort to define the exploration of this planet by human crews, known as the Evolvable Mars Campaign (EMC), provides the context in which these EZs and ROIs are being considered. The EMC spans all aspects of a human Mars mission including launch from Earth, transit to and from Mars, and operations on the surface of Mars. Studies related to Mars surface operations and related system capabilities have led to the current definition of an EZ as well as ROIs. An EZ is a collection of ROIs that are located within approximately 100 kilometers of a centralized landing site. ROIs are areas that are relevant for scientific investigation and/or development/maturation of capabilities and resources necessary for a sustainable human presence. The EZ also contains one or more landing sites and a habitation site that will be used by multiple human crews during missions to explore and utilize the ROIs within the EZ. With the EMC as a conceptual basis, the EZ model has been refined to a point where specific site selection criteria for scientific exploration and in situ resource utilization can be defined. In 2015 these criteria were distributed to the planetary sciences community and the in situ resource utilization and civil engineering communities as part of a call for EZ proposals. The resulting "First Landing Site/Exploration Zone Workshop for Human Missions to the Surface of Mars" was held in October 2015 during which 47 proposals for EZs and ROIs were presented and discussed. Proposed locations spanned all longitudes and all allowable latitudes (+/- 50 degrees). Proposed justification for selecting one of these EZs also spanned a significant portion of the scientific and resource criteria provided to the community. Workshop results will be used to prepare for

  19. Investigation of Aerodynamic and Aerodynamic and Radiometric Land Surface Temperatures

    NASA Technical Reports Server (NTRS)

    Crago, Richard D.; Friedl, Mark; Kustas, William; Wang, Ye-Qiao

    2003-01-01

    The overall goal of the project was to reconcile the difference between T(sub s,r) and T(sub aero), while maintaining consistency within models and with theory and data. The project involved collaboration between researchers at Bucknell University, Boston University, University of mode Island, and the USDNARS Hydrology Laboratory. This report focuses on the work done at Bucknell, which used an analytical continuous-source flux model developed by Crago (1998), based on work by Brutsaert and Sugita (1996) to generate fluxes at all levels of the canopy. Named ALARM [Analytical Land- Atmosphere-Radiometer Model] by Suleiman and Crago (2002), the model assumes the foliage has an exponential vertical temperature profile. The same profile is felt by the within-canopy turbulence and 'seen" by a radiometer viewing the surface from any zenith view angle. ALARM converts radiometric surface temperatures taken from any view angle into a clearly-defined version of Taero called the equivalent isothermal surface temperature T(sub s,j), and then calculates the sensible heat flux H using Monin-Obukhov similarity theory. This allows remotely sensed Ts,r measurements to be used to produce high quality sensible and latent heat flux estimates, or to validate or update the surface temperature produced by SVATs in climate or mesoscale models.

  20. 30 CFR 762.13 - Land exempt from designation as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... surface coal mining operations. 762.13 Section 762.13 Mineral Resources OFFICE OF SURFACE MINING... AREAS AS UNSUITABLE FOR SURFACE COAL MINING OPERATIONS § 762.13 Land exempt from designation as unsuitable for surface coal mining operations. The requirements of this part do not apply to— (a) Lands...

  1. 30 CFR 762.13 - Land exempt from designation as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... surface coal mining operations. 762.13 Section 762.13 Mineral Resources OFFICE OF SURFACE MINING... AREAS AS UNSUITABLE FOR SURFACE COAL MINING OPERATIONS § 762.13 Land exempt from designation as unsuitable for surface coal mining operations. The requirements of this part do not apply to— (a) Lands...

  2. Developing first time-series of land surface temperature from AATSR with uncertainty estimates

    NASA Astrophysics Data System (ADS)

    Ghent, Darren; Remedios, John

    2013-04-01

    Land surface temperature (LST) is the radiative skin temperature of the land, and is one of the key parameters in the physics of land-surface processes on regional and global scales. Earth Observation satellites provide the opportunity to obtain global coverage of LST approximately every 3 days or less. One such source of satellite retrieved LST has been the Advanced Along-Track Scanning Radiometer (AATSR); with LST retrieval being implemented in the AATSR Instrument Processing Facility in March 2004. Here we present first regional and global time-series of LST data from AATSR with estimates of uncertainty. Mean changes in temperature over the last decade will be discussed along with regional patterns. Although time-series across all three ATSR missions have previously been constructed (Kogler et al., 2012), the use of low resolution auxiliary data in the retrieval algorithm and non-optimal cloud masking resulted in time-series artefacts. As such, considerable ESA supported development has been carried out on the AATSR data to address these concerns. This includes the integration of high resolution auxiliary data into the retrieval algorithm and subsequent generation of coefficients and tuning parameters, plus the development of an improved cloud mask based on the simulation of clear sky conditions from radiance transfer modelling (Ghent et al., in prep.). Any inference on this LST record is though of limited value without the accompaniment of an uncertainty estimate; wherein the Joint Committee for Guides in Metrology quote an uncertainty as "a parameter associated with the result of a measurement that characterizes the dispersion of the values that could reasonably be attributed to the measurand that is the value of the particular quantity to be measured". Furthermore, pixel level uncertainty fields are a mandatory requirement in the on-going preparation of the LST product for the upcoming Sea and Land Surface Temperature (SLSTR) instrument on-board Sentinel-3

  3. NASA Low Visibility Landing and Surface Operations (LVLASO) Atlanta Demonstration: Surveillance Systems Performance Analysis

    NASA Technical Reports Server (NTRS)

    Cassell, Rick; Evers, Carl; Hicok, Dan; Lee, Derrick

    1999-01-01

    NASA conducted a series of flight experiments at Hartsfield Atlanta International Airport as part of the Low Visibility Landing and Surface Operations (LVLASO) Program. LVLASO is one of the subelements of the NASA Terminal Area Productivity (TAP) Program, which is focused on providing technology and operating procedures for achieving clear-weather airport capacity in instrument-weather conditions, while also improving safety. LVLASO is investigating various technologies to be applied to airport surface operations, including advanced flight deck displays and surveillance systems. The purpose of this report is to document the performance of the surveillance systems tested as part of the LVLASO flight experiment. There were three surveillance sensors tested: primary radar using Airport Surface Detection Equipment (ASDE-3) and the Airport Movement Area Safety System (AMASS), Multilateration using the Airport Surface Target Identification System (ATIDS), and Automatic Dependent Surveillance - Broadcast (ADS-B) operating at 1090 MHz. The performance was compared to the draft requirements of the ICAO Advanced Surface Movement Guidance and Control System (A-SMGCS). Performance parameters evaluated included coverage, position accuracy, and update rate. Each of the sensors was evaluated as a stand alone surveillance system.

  4. Estimation of Surface Air Temperature Over Central and Eastern Eurasia from MODIS Land Surface Temperature

    NASA Technical Reports Server (NTRS)

    Shen, Suhung; Leptoukh, Gregory G.

    2011-01-01

    Surface air temperature (T(sub a)) is a critical variable in the energy and water cycle of the Earth.atmosphere system and is a key input element for hydrology and land surface models. This is a preliminary study to evaluate estimation of T(sub a) from satellite remotely sensed land surface temperature (T(sub s)) by using MODIS-Terra data over two Eurasia regions: northern China and fUSSR. High correlations are observed in both regions between station-measured T(sub a) and MODIS T(sub s). The relationships between the maximum T(sub a) and daytime T(sub s) depend significantly on land cover types, but the minimum T(sub a) and nighttime T(sub s) have little dependence on the land cover types. The largest difference between maximum T(sub a) and daytime T(sub s) appears over the barren and sparsely vegetated area during the summer time. Using a linear regression method, the daily maximum T(sub a) were estimated from 1 km resolution MODIS T(sub s) under clear-sky conditions with coefficients calculated based on land cover types, while the minimum T(sub a) were estimated without considering land cover types. The uncertainty, mean absolute error (MAE), of the estimated maximum T(sub a) varies from 2.4 C over closed shrublands to 3.2 C over grasslands, and the MAE of the estimated minimum Ta is about 3.0 C.

  5. 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

  6. 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.

  7. Implementation of diverse tree hydraulics in a land surface model

    NASA Astrophysics Data System (ADS)

    Wolf, A.; Shevliakova, E.; Malyshev, S.; Weng, E.; Pacala, S. W.

    2013-12-01

    Increasing attention has been devoted to the occurence of drought kill in forests worldwide. These mortality events are significant disruptions to the terrestrial carbon cycle, but the mechanisms required to represent drought kill are not represented in terrestrial carbon cycle models. In part, this is due to the challenge of representing the diversity of hydraulic strategies, which include stomatal sensitivity to water deficit and woody tissue vulnerability to cavitation at low water potential. In part, this is due to the challenge of representing this boundary value problem numerically, because the hydraulic components determine water potential at the leaf, but the stomatal conductance on the leaf also determines the hydraulic gradients within the plant. This poster will describe the development of a land surface model parameterization of diverse tree hydraulic strategies.

  8. Land surface temperature measurements from EOS MODIS data

    NASA Technical Reports Server (NTRS)

    Wan, Zhengming

    1993-01-01

    The task objectives of this reporting phase included: (1) completing the draft of the LST Algorithms Theoretical Basic Document by July 30, 1993; (2) making a detailed characterization of the thermal infrared measurement system including spectrometer, blackbody, and radiation sources; (3) making TIR spectral measurements of water and snow-cover surfaces with the MIDAC M2401 spectrometer; and (4) making conceptual and engineering design of an accessory system for spectrometric measurements at variable angles. These objectives are based on the requirements by the MODIS Science Team and the unique challenge in the development of MODIS LST algorithms: to acquire accurate spectral emissivity data of land covers in the near-term and to make ground validations of the LST product in the long-term with a TIR measurement system.

  9. Reconstruction of MODIS daily land surface temperature under clouds

    NASA Astrophysics Data System (ADS)

    Sun, L.; Gao, F.; Chen, Z.; Song, L.; Xie, D.

    2015-12-01

    Land surface temperature (LST), generally defined as the skin temperature of the Earth's surface, controls the process of evapotranspiration, surface energy balance, soil moisture change and climate change. Moderate Resolution Imaging Spectrometer (MODIS) is equipped with 1km resolution thermal sensor andcapable of observing the earth surface at least once per day.Thermal infrared bands cannot penetrate cloud, which means we cannot get consistency drought monitoring condition at one area. However, the cloudy-sky conditions represent more than half of the actual day-to-day weather around the global. In this study, we developed an LST filled model based on the assumption that under good weather condition, LST difference between two nearby pixels are similar among the closest 8 days. We used all the valid pixels covered by a 9*9 window to reconstruct the gap LST. Each valid pixel is assigned a weight which is determined by the spatial distance and the spectral similarity. This model is applied in the Middle-East of China including Gansu, Ningxia, Shaanxi province. The terrain is complicated in this area including plain and hill. The MODIS daily LST product (MOD11A3) from 2000 to 2004 is tested. Almost all the gap pixels are filled, and the terrain information is reconstructed well and smoothly. We masked two areas in order to validate the model, one located in the plain, another located in the hill. The correlation coefficient is greater than 0.8, even up to 0.92 in a few days. We also used ground measured day maximum and mean surface temperature to valid our model. Although both the temporal and spatial scale are different between ground measured temperature and MODIS LST, they agreed well in all the stations. This LST filled model is operational because it only needs LST and reflectance, and does not need other auxiliary information such as climate factors. We will apply this model to more regions in the future.

  10. [Research advances in simulating land water-carbon coupling].

    PubMed

    Liu, Ning; Sun, Peng-Sen; Liu, Shi-Rong

    2012-11-01

    The increasing demand of adaptive management of land, forest, and water resources under the background of global change and water resources crisis has promoted the comprehensive study of coupling ecosystem water and carbon cycles and their restrictive relations. To construct the water-carbon coupling model and to approach the ecosystem water-carbon balance and its interactive response mechanisms under climate change at multiple spatiotemporal scales is nowadays a major concern. After reviewing the coupling relationships of water and carbon at various scales, this paper explored the implications and estimation methods of the key processes and related parameters of water-carbon coupling, the construction of evapotranspiration model at large scale based on RS, and the importance of this model in water-carbon coupling researches. The applications of assimilative multivariate data in water-carbon coupling researches under future climate change scenarios were also prospected.

  11. Global Intercomparison of 12 Land Surface Heat Flux Estimates

    NASA Technical Reports Server (NTRS)

    Jimenez, C.; Prigent, C.; Mueller, B.; Seneviratne, S. I.; McCabe, M. F.; Wood, E. F.; Rossow, W. B.; Balsamo, G.; Betts, A. K.; Dirmeyer, P. A.; Fisher, J. B.; Jung, M.; Kanamitsu, M.; Reichle, R. H.; Reichstein, M.; Rodell, M.; Sheffield, J.; Tu, K.; Wang, K.

    2011-01-01

    A global intercomparison of 12 monthly mean land surface heat flux products for the period 1993-1995 is presented. The intercomparison includes some of the first emerging global satellite-based products (developed at Paris Observatory, Max Planck Institute for Biogeochemistry, University of California Berkeley, University of Maryland, and Princeton University) and examples of fluxes produced by reanalyses (ERA-Interim, MERRA, NCEP-DOE) and off-line land surface models (GSWP-2, GLDAS CLM/ Mosaic/Noah). An intercomparison of the global latent heat flux (Q(sub le)) annual means shows a spread of approx 20 W/sq m (all-product global average of approx 45 W/sq m). A similar spread is observed for the sensible (Q(sub h)) and net radiative (R(sub n)) fluxes. In general, the products correlate well with each other, helped by the large seasonal variability and common forcing data for some of the products. Expected spatial distributions related to the major climatic regimes and geographical features are reproduced by all products. Nevertheless, large Q(sub le)and Q(sub h) absolute differences are also observed. The fluxes were spatially averaged for 10 vegetation classes. The larger Q(sub le) differences were observed for the rain forest but, when normalized by mean fluxes, the differences were comparable to other classes. In general, the correlations between Q(sub le) and R(sub n) were higher for the satellite-based products compared with the reanalyses and off-line models. The fluxes were also averaged for 10 selected basins. The seasonality was generally well captured by all products, but large differences in the flux partitioning were observed for some products and basins.

  12. Advances in POST2 End-to-End Descent and Landing Simulation for the ALHAT Project

    NASA Technical Reports Server (NTRS)

    Davis, Jody L.; Striepe, Scott A.; Maddock, Robert W.; Hines, Glenn D.; Paschall, Stephen, II; Cohanim, Babak E.; Fill, Thomas; Johnson, Michael C.; Bishop, Robert H.; DeMars, Kyle J.; Sostaric, Ronald r.; Johnson, Andrew E.

    2008-01-01

    Program to Optimize Simulated Trajectories II (POST2) is used as a basis for an end-to-end descent and landing trajectory simulation that is essential in determining design and integration capability and system performance of the lunar descent and landing system and environment models for the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project. The POST2 simulation provides a six degree-of-freedom capability necessary to test, design and operate a descent and landing system for successful lunar landing. This paper presents advances in the development and model-implementation of the POST2 simulation, as well as preliminary system performance analysis, used for the testing and evaluation of ALHAT project system models.

  13. Land use/land cover water quality nexus: quantifying anthropogenic influences on surface water quality.

    PubMed

    Wilson, Cyril O

    2015-07-01

    Anthropogenic forces widely influence the composition, configuration, and trend of land use and land cover (LULC) changes with potential implications for surface water quality. These changes have the likelihood of generating non-point source pollution with additional environmental implications for terrestrial and aquatic ecosystems. Monitoring the scope and trajectory of LULC change is pivotal for region-wide planning, tracking the sustainability of natural resources, and meeting the information needs of policy makers. A good comprehension of the dynamics of anthropogenic drivers (proximate and underlying) that influence such changes in LULC is important because any potential adverse change in LULC that may be inimical to sustainable water quality might be addressed at the anthropogenic driver level rather than the LULC change stage. Using a dense time stack of Landsat-5 Thematic Mapper images, a hydrologic water quality and socio-geospatial modeling framework, this study quantifies the role of anthropogenic drivers of LULC change on total suspended solids and total phosphorus concentrations in the Lower Chippewa River Watershed, Wisconsin, at three time steps-1990, 2000, and 2010. Results of the study demonstrated that proximate drivers of LULC change accounted for between 32 and 59% of the concentration and spatial distribution of total suspended solids, while the extent of phosphorus impairment attributed to the proximate drivers ranged between 31 and 42%. PMID:26065891

  14. Land use/land cover water quality nexus: quantifying anthropogenic influences on surface water quality.

    PubMed

    Wilson, Cyril O

    2015-07-01

    Anthropogenic forces widely influence the composition, configuration, and trend of land use and land cover (LULC) changes with potential implications for surface water quality. These changes have the likelihood of generating non-point source pollution with additional environmental implications for terrestrial and aquatic ecosystems. Monitoring the scope and trajectory of LULC change is pivotal for region-wide planning, tracking the sustainability of natural resources, and meeting the information needs of policy makers. A good comprehension of the dynamics of anthropogenic drivers (proximate and underlying) that influence such changes in LULC is important because any potential adverse change in LULC that may be inimical to sustainable water quality might be addressed at the anthropogenic driver level rather than the LULC change stage. Using a dense time stack of Landsat-5 Thematic Mapper images, a hydrologic water quality and socio-geospatial modeling framework, this study quantifies the role of anthropogenic drivers of LULC change on total suspended solids and total phosphorus concentrations in the Lower Chippewa River Watershed, Wisconsin, at three time steps-1990, 2000, and 2010. Results of the study demonstrated that proximate drivers of LULC change accounted for between 32 and 59% of the concentration and spatial distribution of total suspended solids, while the extent of phosphorus impairment attributed to the proximate drivers ranged between 31 and 42%.

  15. Assimilation of GOES Land Surface Data into a Mesoscale Models

    NASA Technical Reports Server (NTRS)

    Lapenta, William M.; Suggs, Ron; McNider, Richard T.; Jedlovec, Gary; Dembek, Scott; Goodman, H. Michael (Technical Monitor)

    2001-01-01

    A technique has been developed for assimilating Geostationary Operational Environmental Satellite (GOES)-derived skin temperature tendencies and insolation into the surface energy budget equation of a mesoscale model so that the simulated rate of temperature change closely agrees with the satellite observations. A critical assumption of the technique is that the availability of moisture (either from the soil or vegetation) is the least known term in the model's surface energy budget. Therefore, the simulated latent heat flux, which is a function of surface moisture availability, is adjusted based upon differences between the modeled and satellite-observed skin temperature tendencies. An advantage of this technique is that satellite temperature tendencies are assimilated in an energetically consistent manner that avoids energy imbalances and surface stability problems that arise from direct assimilation of surface shelter temperatures. The fact that the rate of change of the satellite skin temperature is used rather than the absolute temperature means that sensor calibration is not as critical. The assimilation technique has been applied to the Oklahoma-Kansas region during the spring-summer 2000 time period when dynamic changes in vegetation cover occur. In April, central Oklahoma is characterized by large NDVI associated with winter wheat while surrounding areas are primarily rangeland with lower NDVI. In July the vegetation pattern reverses as the central wheat area changes to low NDVI due to harvesting and the surrounding rangeland is greener than it was in April. The goal of this study is to determine if assimilating satellite land surface data can improve simulation of the complex spatial distribution of surface energy and water fluxes across this region. The PSU/NCAR NM5 V3 system is used in this study. The grid configuration consists of a 36-km CONUS domain and a 12-km nest over the area of interest. Bulk verification statistics (BIAS and RMSE) of surface

  16. Modeling the Behaviour of an Advanced Material Based Smart Landing Gear System for Aerospace Vehicles

    SciTech Connect

    Varughese, Byji; Dayananda, G. N.; Rao, M. Subba

    2008-07-29

    The last two decades have seen a substantial rise in the use of advanced materials such as polymer composites for aerospace structural applications. In more recent years there has been a concerted effort to integrate materials, which mimic biological functions (referred to as smart materials) with polymeric composites. Prominent among smart materials are shape memory alloys, which possess both actuating and sensory functions that can be realized simultaneously. The proper characterization and modeling of advanced and smart materials holds the key to the design and development of efficient smart devices/systems. This paper focuses on the material characterization; modeling and validation of the model in relation to the development of a Shape Memory Alloy (SMA) based smart landing gear (with high energy dissipation features) for a semi rigid radio controlled airship (RC-blimp). The Super Elastic (SE) SMA element is configured in such a way that it is forced into a tensile mode of high elastic deformation. The smart landing gear comprises of a landing beam, an arch and a super elastic Nickel-Titanium (Ni-Ti) SMA element. The landing gear is primarily made of polymer carbon composites, which possess high specific stiffness and high specific strength compared to conventional materials, and are therefore ideally suited for the design and development of an efficient skid landing gear system with good energy dissipation characteristics. The development of the smart landing gear in relation to a conventional metal landing gear design is also dealt with.

  17. Modeling the Behaviour of an Advanced Material Based Smart Landing Gear System for Aerospace Vehicles

    NASA Astrophysics Data System (ADS)

    Varughese, Byji; Dayananda, G. N.; Rao, M. Subba

    2008-07-01

    The last two decades have seen a substantial rise in the use of advanced materials such as polymer composites for aerospace structural applications. In more recent years there has been a concerted effort to integrate materials, which mimic biological functions (referred to as smart materials) with polymeric composites. Prominent among smart materials are shape memory alloys, which possess both actuating and sensory functions that can be realized simultaneously. The proper characterization and modeling of advanced and smart materials holds the key to the design and development of efficient smart devices/systems. This paper focuses on the material characterization; modeling and validation of the model in relation to the development of a Shape Memory Alloy (SMA) based smart landing gear (with high energy dissipation features) for a semi rigid radio controlled airship (RC-blimp). The Super Elastic (SE) SMA element is configured in such a way that it is forced into a tensile mode of high elastic deformation. The smart landing gear comprises of a landing beam, an arch and a super elastic Nickel-Titanium (Ni-Ti) SMA element. The landing gear is primarily made of polymer carbon composites, which possess high specific stiffness and high specific strength compared to conventional materials, and are therefore ideally suited for the design and development of an efficient skid landing gear system with good energy dissipation characteristics. The development of the smart landing gear in relation to a conventional metal landing gear design is also dealt with.

  18. Advances in surfaces and osseointegration in implantology. Biomimetic surfaces

    PubMed Central

    Albertini, Matteo; Fernandez-Yague, Marc; Lázaro, Pedro; Herrero-Climent, Mariano; Bullon, Pedro; Gil, Francisco-Javier

    2015-01-01

    The present work is a revision of the processes occurring in osseointegration of titanium dental implants according to different types of surfaces -namely, polished surfaces, rough surfaces obtained from subtraction methods, as well as the new hydroxyapatite biomimetic surfaces obtained from thermochemical processes. Hydroxyapatite’s high plasma-projection temperatures have proven to prevent the formation of crystalline apatite on the titanium dental implant, but lead to the formation of amorphous calcium phosphate (i.e., with no crystal structure) instead. This layer produce some osseointegration yet the calcium phosphate layer will eventually dissolve and leave a gap between the bone and the dental implant, thus leading to osseointegration failure due to bacterial colonization. A new surface -recently obtained by thermochemical processes- produces, by crystallization, a layer of apatite with the same mineral content as human bone that is chemically bonded to the titanium surface. Osseointegration speed was tested by means of minipigs, showing bone formation after 3 to 4 weeks, with the security that a dental implant can be loaded. This surface can be an excellent candidate for immediate or early loading procedures. Key words:Dental implants, implants surfaces, osseointegration, biomimetics surfaces. PMID:25662555

  19. Impacts of forest harvest on cold season land surface conditions and land-atmosphere interactions in northern Great Lakes states

    NASA Astrophysics Data System (ADS)

    Garcia, Matthew; Özdogan, Mutlu; Townsend, Philip A.

    2014-09-01

    Land cover change, including temporary disturbances such as forest harvests, can significantly affect established regimes of surface energy balance and moisture exchange, altering flux processes that drive weather and climate. We examined the impacts of forest harvest on winter land-atmosphere interactions in a temperate region using high-resolution numerical modeling methods in paired simulations. Using the WRF-ARW atmospheric model and the Noah land surface model, we simulated the balance of surface sensible and latent heat fluxes and the development and dissipation of a stable nocturnal boundary layer during generally calm synoptic conditions. Our results show reduced daily-average snow-covered land surface sensible heat flux (by 80%) and latent heat flux (by 60%) to the atmosphere in forest clearings due to albedo effects and rebalancing of the surface energy budget. We found a land surface cooling effect (-8 W m-2) in snow-covered cleared areas, consistent with prior modeling studies and conceptual understanding of the mechanisms for midlatitude deforestation to offset anthropogenic global warming at local scales. Results also demonstrate impacts of forest clearing on the passage of a weak cold front due to altered near-surface winds and boundary layer stability. We show significant differences in both surface conditions and fluxes between harvested and undisturbed forest areas. Our results demonstrate the potential utility of high-resolution remote sensing analyses to represent transient land cover changes in model simulations of weather and climate, which are usually undertaken at coarser resolutions and often overlook these changes at the land surface.

  20. Global data on land surface parameters from NOAA AVHRR for use in numerical climate models

    SciTech Connect

    Gutman, G.G. )

    1994-05-01

    This paper reviews satellite datasets from the NOAA Advanced Very High Resolution Radiometer that could be employed in support of numerical climate modeling at regional and global scales. Presently available NOAA operational and research datasets of different resolutions as well as the NASA-NOAA Pathfinder dataset, available in the near future, are briefly described. Specific problems in deriving surface characteristics in the context of their potential use of models are discussed. Possible ways of solving these problems are briefly described, based on the state-of-the-art level of understanding in this area of research. Some examples of seasonal variability of AVHRR-derived surface parameters, such as albedo, greenness, and clear-sky midafternoon temperature, for different climatic regions are presented. Validation issues and potential operational production of such land climate parameters are discussed.

  1. Information-Theoretic Benchmarking of Land Surface Models

    NASA Astrophysics Data System (ADS)

    Nearing, Grey; Mocko, David; Kumar, Sujay; Peters-Lidard, Christa; Xia, Youlong

    2016-04-01

    Benchmarking is a type of model evaluation that compares model performance against a baseline metric that is derived, typically, from a different existing model. Statistical benchmarking was used to qualitatively show that land surface models do not fully utilize information in boundary conditions [1] several years before Gong et al [2] discovered the particular type of benchmark that makes it possible to *quantify* the amount of information lost by an incorrect or imperfect model structure. This theoretical development laid the foundation for a formal theory of model benchmarking [3]. We here extend that theory to separate uncertainty contributions from the three major components of dynamical systems models [4]: model structures, model parameters, and boundary conditions describe time-dependent details of each prediction scenario. The key to this new development is the use of large-sample [5] data sets that span multiple soil types, climates, and biomes, which allows us to segregate uncertainty due to parameters from the two other sources. The benefit of this approach for uncertainty quantification and segregation is that it does not rely on Bayesian priors (although it is strictly coherent with Bayes' theorem and with probability theory), and therefore the partitioning of uncertainty into different components is *not* dependent on any a priori assumptions. We apply this methodology to assess the information use efficiency of the four land surface models that comprise the North American Land Data Assimilation System (Noah, Mosaic, SAC-SMA, and VIC). Specifically, we looked at the ability of these models to estimate soil moisture and latent heat fluxes. We found that in the case of soil moisture, about 25% of net information loss was from boundary conditions, around 45% was from model parameters, and 30-40% was from the model structures. In the case of latent heat flux, boundary conditions contributed about 50% of net uncertainty, and model structures contributed

  2. Two Surface Temperature Retrieval Methods Compared Over Agricultural Lands

    NASA Technical Reports Server (NTRS)

    French, Andrew N.; Schmugge, Thomas J.; Jacob, Frederic; Ogawa, Kenta; Houser, Paul R. (Technical Monitor)

    2002-01-01

    Accurate, spatially distributed surface temperatures are required for modeling evapotranspiration (ET) over agricultural fields under wide ranging conditions, including stressed and unstressed vegetation. Modeling approaches that use surface temperature observations, however, have the burden of estimating surface emissivities. Emissivity estimation, the subject of much recent research, is facilitated by observations in multiple thermal infrared bands. But it is nevertheless a difficult task. Using observations from a multiband thermal sensor, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), estimated surface emissivities and temperatures are retrieved in two different ways: the temperature emissivity separation approach (TES) and the normalized emissivity approach (NEM). Both rely upon empirical relationships, but the assumed relationships are different. TES relies upon a relationship between the minimum spectral emissivity and the range of observed emissivities. NEM relies upon an assumption that at least one thermal band has a pre-determined emissivity (close to 1.0). The benefits and consequences of each approach will be demonstrated for two different landscapes: one in central Oklahoma, USA and another in southern New Mexico.

  3. A framework for global diurnally-resolved observations of Land Surface Temperature

    NASA Astrophysics Data System (ADS)

    Ghent, Darren; Remedios, John

    2014-05-01

    Land surface temperature (LST) is the radiative skin temperature of the land, and is one of the key parameters in the physics of land-surface processes on regional and global scales. Being a key boundary condition in land surface models, which determine the surface to atmosphere fluxes of heat, water and carbon; thus influencing cloud cover, precipitation and atmospheric chemistry predictions within Global models, the requirement for global diurnal observations of LST is well founded. Earth Observation satellites offer an opportunity to obtain global coverage of LST, with the appropriate exploitation of data from multiple instruments providing a capacity to resolve the diurnal cycle on a global scale. Here we present a framework for the production of global, diurnally resolved, data sets for LST which is a key request from users of LST data. We will show how the sampling of both geostationary and low earth orbit data sets could conceptually be employed to build combined, multi-sensor, pole-to-pole data sets. Although global averages already exist for individual instruments and merging of geostationary based LST is already being addressed operationally (Freitas, et al., 2013), there are still a number of important challenges to overcome. In this presentation, we will consider three of the issues still open in LST remote sensing: 1) the consistency amongst retrievals; 2) the clear-sky bias and its quantification; and 3) merging methods and the propagation of uncertainties. For example, the combined use of both geostationary earth orbit (GEO) and low earth orbit (LEO) data, and both infra-red and microwave data are relatively unexplored but are necessary to make the most progress. Hence this study will suggest what is state-of-the-art and how considerable advances can be made, accounting also for recent improvements in techniques and data quality. The GlobTemperature initiative under the Data User Element of ESA's 4th Earth Observation Envelope Programme (2013

  4. A framework for global diurnally-resolved observations of Land Surface Temperature

    NASA Astrophysics Data System (ADS)

    Ghent, D.; Remedios, J.; Pinnock, S.

    2013-12-01

    Land surface temperature (LST) is the radiative skin temperature of the land, and is one of the key parameters in the physics of land-surface processes on regional and global scales. Being a key boundary condition in land surface models, which determine the surface to atmosphere fluxes of heat, water and carbon; thus influencing cloud cover, precipitation and atmospheric chemistry predictions within Global models, the requirement for global diurnal observations of LST is well founded. Earth Observation satellites offer an opportunity to obtain global coverage of LST, with the appropriate exploitation of data from multiple instruments providing a capacity to resolve the diurnal cycle on a global scale. Here we present a framework for the production of global, diurnally resolved, data sets for LST which is a key request from users of LST data. We will show how the sampling of both geostationary and low earth orbit data sets could conceptually be employed to build combined, multi-sensor, pole-to-pole data sets. Although global averages already exist for individual instruments and merging of geostationary based LST is already being addressed operationally (Freitas, et al., 2013), there are still a number of important challenges to overcome. In this presentation, we will consider three of the issues still open in LST remote sensing: 1) the consistency amongst retrievals; 2) the clear-sky bias and its quantification; and 3) merging methods and the propagation of uncertainties. For example, the combined use of both geostationary earth orbit (GEO) and low earth orbit (LEO) data, and both infra-red and microwave data are relatively unexplored but are necessary to make the most progress. Hence this study will suggest what is state-of-the-art and how considerable advances can be made, accounting also for recent improvements in techniques and data quality. The GlobTemperature initiative under the Data User Element of ESA's 4th Earth Observation Envelope Programme (2013

  5. Satellite-based land use mapping: comparative analysis of Landsat-8, Advanced Land Imager, and big data Hyperion imagery

    NASA Astrophysics Data System (ADS)

    Pervez, Wasim; Uddin, Vali; Khan, Shoab Ahmad; Khan, Junaid Aziz

    2016-04-01

    Until recently, Landsat technology has suffered from low signal-to-noise ratio (SNR) and comparatively poor radiometric resolution, which resulted in limited application for inland water and land use/cover mapping. The new generation of Landsat, the Landsat Data Continuity Mission carrying the Operational Land Imager (OLI), has improved SNR and high radiometric resolution. This study evaluated the utility of orthoimagery from OLI in comparison with the Advanced Land Imager (ALI) and hyperspectral Hyperion (after preprocessing) with respect to spectral profiling of classes, land use/cover classification, classification accuracy assessment, classifier selection, study area selection, and other applications. For each data source, the support vector machine (SVM) model outperformed the spectral angle mapper (SAM) classifier in terms of class discrimination accuracy (i.e., water, built-up area, mixed forest, shrub, and bare soil). Using the SVM classifier, Hyperion hyperspectral orthoimagery achieved higher overall accuracy than OLI and ALI. However, OLI outperformed both hyperspectral Hyperion and multispectral ALI using the SAM classifier, and with the SVM classifier outperformed ALI in terms of overall accuracy and individual classes. The results show that the new generation of Landsat achieved higher accuracies in mapping compared with the previous Landsat multispectral satellite series.

  6. Estimation of land surface water and energy balance parameters using conditional sampling of surface states

    NASA Astrophysics Data System (ADS)

    Farhadi, Leila; Entekhabi, Dara; Salvucci, Guido; Sun, Jian

    2014-02-01

    Numerical models of heat and moisture diffusion in the soil-vegetation-atmosphere continuum are linked through the moisture flux from the surface to the atmosphere. This mass flux represents a heat exchange as latent heat flux, coupling water, and energy balance equations. In this paper, a new approach for estimating key parameters governing moisture and heat diffusion equation and the closure function which links these equations, is introduced. Parameters of the system are estimated by developing objective functions that link atmospheric forcing, surface states, and unknown parameters. This approach is based on conditional averaging of heat and moisture diffusion equations on land surface temperature and moisture states, respectively. A single objective function is expressed that measures moisture and temperature-dependent errors solely in terms of observed forcings and surface states. This objective function is minimized with respect to the parameters to identify evaporation and drainage models and estimate water and energy balance flux components. The approach is calibration free (surface flux observations are not required), it is not hampered by missing data and does not require continuous records. Uncertainty of parameter estimates is obtained from the inverse of Hessian of the objective function, which is an approximation of the error covariance matrix. Uncertainty analysis and analysis of the covariance approximation, guides the formulation of a well-posed estimation problem. Accuracy of this method is examined through its application over three different field sites. This approach can be applied to diverse climates and land surface conditions with different spatial scales, using remotely sensed measurements.

  7. Advances in surfaces and osseointegration in implantology. Biomimetic surfaces.

    PubMed

    Albertini, Matteo; Fernandez-Yague, Marc; Lázaro, Pedro; Herrero-Climent, Mariano; Rios-Santos, Jose-Vicente; Bullon, Pedro; Gil, Francisco-Javier

    2015-05-01

    The present work is a revision of the processes occurring in osseointegration of titanium dental implants according to different types of surfaces -namely, polished surfaces, rough surfaces obtained from subtraction methods, as well as the new hydroxyapatite biomimetic surfaces obtained from thermochemical processes. Hydroxyapatite's high plasma-projection temperatures have proven to prevent the formation of crystalline apatite on the titanium dental implant, but lead to the formation of amorphous calcium phosphate (i.e., with no crystal structure) instead. This layer produce some osseointegration yet the calcium phosphate layer will eventually dissolve and leave a gap between the bone and the dental implant, thus leading to osseointegration failure due to bacterial colonization. A new surface -recently obtained by thermochemical processes- produces, by crystallization, a layer of apatite with the same mineral content as human bone that is chemically bonded to the titanium surface. Osseointegration speed was tested by means of minipigs, showing bone formation after 3 to 4 weeks, with the security that a dental implant can be loaded. This surface can be an excellent candidate for immediate or early loading procedures.

  8. Land surface phenological response to decadal climate variability across Australia using satellite remote sensing

    NASA Astrophysics Data System (ADS)

    Broich, M.; Huete, A.; Tulbure, M. G.; Ma, X.; Xin, Q.; Paget, M.; Restrepo-Coupe, N.; Davies, K.; Devadas, R.; Held, A.

    2014-05-01

    Land surface phenological cycles of vegetation greening and browning are influenced by variability in climatic forcing. Quantitative information on phenological cycles and their variability is important for agricultural applications, wildfire fuel accumulation, land management, land surface modeling, and climate change studies. Most phenology studies have focused on temperature-driven Northern Hemisphere systems, where phenology shows annually reoccurring patterns. Yet, precipitation-driven non-annual phenology of arid and semi-arid systems (i.e. drylands) received much less attention, despite the fact that they cover more than 30% of the global land surface. Here we focused on Australia, the driest inhabited continent with one of the most variable rainfall climates in the world and vast areas of dryland systems. Detailed and internally consistent studies investigating phenological cycles and their response to climate variability across the entire continent designed specifically for Australian dryland conditions are missing. To fill this knowledge gap and to advance phenological research, we used existing methods more effectively to study geographic and climate-driven variability in phenology over Australia. We linked derived phenological metrics with rainfall and the Southern Oscillation Index (SOI). We based our analysis on Enhanced Vegetation Index (EVI) data from the MODerate Resolution Imaging Spectroradiometer (MODIS) from 2000 to 2013, which included extreme drought and wet years. We conducted a continent-wide investigation of the link between phenology and climate variability and a more detailed investigation over the Murray-Darling Basin (MDB), the primary agricultural area and largest river catchment of Australia. Results showed high inter- and intra-annual variability in phenological cycles. Phenological cycle peaks occurred not only during the austral summer but at any time of the year, and their timing varied by more than a month in the interior of the

  9. Afforestation in China cools local land surface temperature

    PubMed Central

    Peng, Shu-Shi; Piao, Shilong; Zeng, Zhenzhong; Ciais, Philippe; Zhou, Liming; Li, Laurent Z. X.; Myneni, Ranga B.; Yin, Yi; Zeng, Hui

    2014-01-01

    China has the largest afforested area in the world (∼62 million hectares in 2008), and these forests are carbon sinks. The climatic effect of these new forests depends on how radiant and turbulent energy fluxes over these plantations modify surface temperature. For instance, a lower albedo may cause warming, which negates the climatic benefits of carbon sequestration. Here, we used satellite measurements of land surface temperature (LST) from planted forests and adjacent grasslands or croplands in China to understand how afforestation affects LST. Afforestation is found to decrease daytime LST by about 1.1 ± 0.5 °C (mean ± 1 SD) and to increase nighttime LST by about 0.2 ± 0.5 °C, on average. The observed daytime cooling is a result of increased evapotranspiration. The nighttime warming is found to increase with latitude and decrease with average rainfall. Afforestation in dry regions therefore leads to net warming, as daytime cooling is offset by nighttime warming. Thus, it is necessary to carefully consider where to plant trees to realize potential climatic benefits in future afforestation projects. PMID:24516135

  10. Afforestation in China cools local land surface temperature.

    PubMed

    Peng, Shu-Shi; Piao, Shilong; Zeng, Zhenzhong; Ciais, Philippe; Zhou, Liming; Li, Laurent Z X; Myneni, Ranga B; Yin, Yi; Zeng, Hui

    2014-02-25

    China has the largest afforested area in the world (∼62 million hectares in 2008), and these forests are carbon sinks. The climatic effect of these new forests depends on how radiant and turbulent energy fluxes over these plantations modify surface temperature. For instance, a lower albedo may cause warming, which negates the climatic benefits of carbon sequestration. Here, we used satellite measurements of land surface temperature (LST) from planted forests and adjacent grasslands or croplands in China to understand how afforestation affects LST. Afforestation is found to decrease daytime LST by about 1.1 ± 0.5 °C (mean ± 1 SD) and to increase nighttime LST by about 0.2 ± 0.5 °C, on average. The observed daytime cooling is a result of increased evapotranspiration. The nighttime warming is found to increase with latitude and decrease with average rainfall. Afforestation in dry regions therefore leads to net warming, as daytime cooling is offset by nighttime warming. Thus, it is necessary to carefully consider where to plant trees to realize potential climatic benefits in future afforestation projects. PMID:24516135

  11. Spatial validation of large scale land surface models against monthly land surface temperature patterns using innovative performance metrics.

    NASA Astrophysics Data System (ADS)

    Koch, Julian; Siemann, Amanda; Stisen, Simon; Sheffield, Justin

    2016-04-01

    Land surface models (LSMs) are a key tool to enhance process understanding and to provide predictions of the terrestrial hydrosphere and its atmospheric coupling. Distributed LSMs predict hydrological states and fluxes, such as land surface temperature (LST) or actual evapotranspiration (aET), at each grid cell. LST observations are widely available through satellite remote sensing platforms that enable comprehensive spatial validations of LSMs. In spite of the availability of LST data, most validation studies rely on simple cell to cell comparisons and thus do not regard true spatial pattern information. This study features two innovative spatial performance metrics, namely EOF- and connectivity-analysis, to validate predicted LST patterns by three LSMs (Mosaic, Noah, VIC) over the contiguous USA. The LST validation dataset is derived from global High-Resolution-Infrared-Radiometric-Sounder (HIRS) retrievals for a 30 year period. The metrics are bias insensitive, which is an important feature in order to truly validate spatial patterns. The EOF analysis evaluates the spatial variability and pattern seasonality, and attests better performance to VIC in the warm months and to Mosaic and Noah in the cold months. Further, more than 75% of the LST variability can be captured by a single pattern that is strongly driven by air temperature. The connectivity analysis assesses the homogeneity and smoothness of patterns. The LSMs are most reliable at predicting cold LST patterns in the warm months and vice versa. Lastly, the coupling between aET and LST is investigated at flux tower sites and compared against LSMs to explain the identified LST shortcomings.

  12. Human Mars Landing Site and Impacts on Mars Surface Operations

    NASA Technical Reports Server (NTRS)

    Hoffman, Stephen J.; Bussey, Ben

    2016-01-01

    This paper describes NASA's initial steps for identifying and evaluating candidate Exploration Zones (EZs) and Regions of Interests (ROIs) for the first human crews that will explore the surface of Mars. NASA's current effort to define the exploration of this planet by human crews, known as the Evolvable Mars Campaign (EMC), provides the context in which these EZs and ROIs are being considered. The EMC spans all aspects of a human Mars mission including launch from Earth, transit to and from Mars, and operations on the surface of Mars. An EZ is a collection of ROIs located within approximately 100 kilometers of a centralized landing site. ROIs are areas relevant for scientific investigation and/or development/maturation of capabilities and resources necessary for a sustainable human presence. The EZ also contains one or more landing sites and a habitation site that will be used by multiple human crews during missions to explore and utilize the ROIs within the EZ. With the EMC as a conceptual basis, the EZ model has been refined to a point where specific site selection criteria for scientific exploration and in situ resource utilization can be defined. In 2015 these criteria were distributed to the planetary sciences community and the in situ resource utilization and civil engineering communities as part of a call for EZ proposals. The resulting "First Landing Site/Exploration Zone Workshop for Human Missions to the Surface of Mars" was held in October 2015 during which 47 proposals for EZs and ROIs were presented and discussed. Proposed locations spanned all longitudes and all allowable latitudes (+/- 50 degrees). Proposed justification for selecting one of these EZs also spanned a significant portion of the scientific and resource criteria provided to the community. Several important findings resulted from this Workshop including: (a) a strong consensus that, at a scale of 100 km (radius), multiple places on Mars exist that have both sufficient scientific interest

  13. The impact of built-up surfaces on land surface temperatures in Italian urban areas.

    PubMed

    Morabito, Marco; Crisci, Alfonso; Messeri, Alessandro; Orlandini, Simone; Raschi, Antonio; Maracchi, Giampiero; Munafò, Michele

    2016-05-01

    Urban areas are characterized by the very high degree of soil sealing and continuous built-up areas: Italy is one of the European countries with the highest artificial land cover rate, which causes a substantial spatial variation in the land surface temperature (LST), modifying the urban microclimate and contributing to the urban heat island effect. Nevertheless, quantitative data regarding the contribution of different densities of built-up surfaces in determining urban spatial LST changes is currently lacking in Italy. This study, which aimed to provide clear and quantitative city-specific information on annual and seasonal spatial LST modifications resulting from increased urban built-up coverage, was conducted generally throughout the whole year, and specifically in two different periods (cool/cold and warm/hot periods). Four cities (Milan, Rome, Bologna and Florence) were included in the study. The LST layer and the built-up-surface indicator were obtained via use of MODIS remote sensing data products (1km) and a very high-resolution map (5m) of built-up surfaces recently developed by the Italian National Institute for Environmental Protection and Research. The relationships between the dependent (mean daily, daytime and nighttime LST values) and independent (built-up surfaces) variables were investigated through linear regression analyses, and comprehensive built-up-surface-related LST maps were also developed. Statistically significant linear relationships (p<0.001) between built-up surfaces and spatial LST variations were observed in all the cities studied, with a higher impact during the warm/hot period than in the cool/cold ones. Daytime and nighttime LST slope patterns depend on the city size and relative urban morphology. If implemented in the existing city plan, the urban maps of built-up-surface-related LST developed in this study might be able to support more sustainable urban land management practices by identifying the critical areas (Hot

  14. The impact of built-up surfaces on land surface temperatures in Italian urban areas.

    PubMed

    Morabito, Marco; Crisci, Alfonso; Messeri, Alessandro; Orlandini, Simone; Raschi, Antonio; Maracchi, Giampiero; Munafò, Michele

    2016-05-01

    Urban areas are characterized by the very high degree of soil sealing and continuous built-up areas: Italy is one of the European countries with the highest artificial land cover rate, which causes a substantial spatial variation in the land surface temperature (LST), modifying the urban microclimate and contributing to the urban heat island effect. Nevertheless, quantitative data regarding the contribution of different densities of built-up surfaces in determining urban spatial LST changes is currently lacking in Italy. This study, which aimed to provide clear and quantitative city-specific information on annual and seasonal spatial LST modifications resulting from increased urban built-up coverage, was conducted generally throughout the whole year, and specifically in two different periods (cool/cold and warm/hot periods). Four cities (Milan, Rome, Bologna and Florence) were included in the study. The LST layer and the built-up-surface indicator were obtained via use of MODIS remote sensing data products (1km) and a very high-resolution map (5m) of built-up surfaces recently developed by the Italian National Institute for Environmental Protection and Research. The relationships between the dependent (mean daily, daytime and nighttime LST values) and independent (built-up surfaces) variables were investigated through linear regression analyses, and comprehensive built-up-surface-related LST maps were also developed. Statistically significant linear relationships (p<0.001) between built-up surfaces and spatial LST variations were observed in all the cities studied, with a higher impact during the warm/hot period than in the cool/cold ones. Daytime and nighttime LST slope patterns depend on the city size and relative urban morphology. If implemented in the existing city plan, the urban maps of built-up-surface-related LST developed in this study might be able to support more sustainable urban land management practices by identifying the critical areas (Hot

  15. Remote Sensing of Atlanta's Urban Sprawl and the Distribution of Land Cover and Surface Temperatures

    NASA Technical Reports Server (NTRS)

    Laymon, Charles A.; Estes, Maurice G., Jr.; Quattrochi, Dale A.; Arnold, James E. (Technical Monitor)

    2001-01-01

    Between 1973 and 1992, an average of 20 ha of forest was lost each day to urban expansion of Atlanta, Georgia. Urban surfaces have very different thermal properties than natural surfaces-storing solar energy throughout the day and continuing to release it as sensible heat well after sunset. The resulting heat island effect serves as catalysts for chemical reactions from vehicular exhaust and industrialization leading to a deterioration in air quality. In this study, high spatial resolution multispectral remote sensing data has been used to characterize the type, thermal properties, and distribution of land surface materials throughout the Atlanta metropolitan area. Ten-meter data were acquired with the Advanced Thermal and Land Applications Sensor (ATLAS) on May 11 and 12, 1997. ATLAS is a 15-channel multispectral scanner that incorporates the Landsat TM bands with additional bands in the middle reflective infrared and thermal infrared range. The high spatial resolution permitted discrimination of discrete surface types (e.g., concrete, asphalt), individual structures (e.g., buildings, houses) and their associated thermal characteristics. There is a strong temperature contrast between vegetation and anthropomorphic features. Vegetation has a modal temperature at about 20 C, whereas asphalt shingles, pavement, and buildings have a modal temperature of about 39 C. Broad-leaf vegetation classes are indistinguishable on a thermal basis alone. There is slightly more variability (plus or minus 5 C) among the urban surfaces. Grasses, mixed vegetation and mixed urban surfaces are intermediate in temperature and are characterized by broader temperature distributions with modes of about 29 C. Thermal maps serve as a basis for understanding the distribution of "hotspots", i.e., how landscape features and urban fabric contribute the most heat to the lower atmosphere.

  16. Remote Sensing of Atlanta's Urban Sprawl and the Distribution of Land Cover and Surface Temperature

    NASA Technical Reports Server (NTRS)

    Laymon, Charles A.; Estes, Maurice G., Jr.; Quattrochi, Dale A.; Goodman, H. Michael (Technical Monitor)

    2001-01-01

    Between 1973 and 1992, an average of 20 ha of forest was lost each day to urban expansion of Atlanta, Georgia. Urban surfaces have very different thermal properties than natural surfaces-storing solar energy throughout the day and continuing to release it as sensible heat well after sunset. The resulting heat island effect serves as catalysts for chemical reactions from vehicular exhaust and industrialization leading to a deterioration in air quality. In this study, high spatial resolution multispectral remote sensing data has been used to characterize the type, thermal properties, and distribution of land surface materials throughout the Atlanta metropolitan area. Ten-meter data were acquired with the Advanced Thermal and Land Applications Sensor (ATLAS) on May 11 and 12, 1997. ATLAS is a 15-channel multispectral scanner that incorporates the Landsat TM bands with additional bands in the middle reflective infrared and thermal infrared range. The high spatial resolution permitted discrimination of discrete surface types (e.g., concrete, asphalt), individual structures (e.g., buildings, houses) and their associated thermal characteristics. There is a strong temperature contrast between vegetation and anthropomorphic features. Vegetation has a modal temperature at about 20 C, whereas asphalt shingles, pavement, and buildings have a modal temperature of about 39 C. Broad-leaf vegetation classes are indistinguishable on a thermal basis alone. There is slightly more variability (+/-5 C) among the urban surfaces. Grasses, mixed vegetation and mixed urban surfaces are intermediate in temperature and are characterized by broader temperature distributions with modes of about 29 C. Thermal maps serve as a basis for understanding the distribution of "hotspots", i.e., how landscape features and urban fabric contribute the most heat to the lower atmosphere.

  17. The role of GMES / Sentinels in Land-Surface Earth System Science

    NASA Astrophysics Data System (ADS)

    Moreno, J.

    2009-04-01

    A general trend in the current status of representation of Land Surface schemes into Earth System models is driven by the parameterisation of "cycles" instead of individual processes. Particular emphasis is made to account for couplings among the individual cycles, as between the carbon and water cycles. Moreover, the current tendency is to use the measured data -time series in most cases- together with models, in a data assimilation scenario where inputs from multiple sources are integrated. Such approach is more and more necessary as land models tend to be more complex, and particularly due to the fact that land surface variability is not just driven by physical and chemical processes, but intricate biological processes also altered by anthropogenic influences. Human influences in the land system (land use changes, urban development, etc.) and the impacts of natural disasters are becoming also part of land models, but critical data in high spatial and temporal resolutions are needed to properly model such processes. Until now, problems with data availability, data inconsistency and lack of adequate temporal sampling have limited the potential usefulness of such observations in modelling land surface processes. The availability of the GMES / Sentinel series of satellites represents a quite unique opportunity for consolidation of current tendencies and development of new science based on the new type of data that soon will become available. The usefulness of the different Sentinel missions for Land science has been recognised. Although the Sentinel satellite series were primarily designed to provide observations for operational services and routine applications, there is a growing interest in the scientific community towards the usage of Sentinel data for more advanced and innovative science. Moreover, the availability of consistent time series covering a period of over 20 years opens possibilities never explored before, such as systematic data assimilation

  18. A review of satellite data algorithms for studies of the land surface

    NASA Technical Reports Server (NTRS)

    Sellers, P. J.; Rasool, S. I.; Bolle, H.-J.

    1990-01-01

    The major groups of algorithms used to convert satellite data into land-surface climatological parameters are reviewed. The International Satellite Land-Surface Climatology Project (ISLSCP) and the Satellite Data Algorithm Workshop are described. ISLSCP was initiated to address the research problems associated with interpretation and utilization of satellite data over the earth's land surface. The proceedings of a workshop sponsored by ISLSCP to investigate the state and potential of satellite sensor output into surface parameters is presented. The current status of algorithms used to determine land-surface parameters is assessed; the methodologies that ultilize these parameters and other data for estimates of the surface energy balance are reviewed; and a preliminary assessment of the effort required to construct an operational system for the routine processing of satellite data into land-surface parameters is made.

  19. Advanced entry guidance algorithm with landing footprint computation

    NASA Astrophysics Data System (ADS)

    Leavitt, James Aaron

    The design and performance evaluation of an entry guidance algorithm for future space transportation vehicles is presented. The algorithm performs two functions: on-board trajectory planning and trajectory tracking. The planned longitudinal path is followed by tracking drag acceleration, as is done by the Space Shuttle entry guidance. Unlike the Shuttle entry guidance, lateral path curvature is also planned and followed. A new trajectory planning function for the guidance algorithm is developed that is suitable for suborbital entry and that significantly enhances the overall performance of the algorithm for both orbital and suborbital entry. In comparison with the previous trajectory planner, the new planner produces trajectories that are easier to track, especially near the upper and lower drag boundaries and for suborbital entry. The new planner accomplishes this by matching the vehicle's initial flight path angle and bank angle, and by enforcing the full three-degree-of-freedom equations of motion with control derivative limits. Insights gained from trajectory optimization results contribute to the design of the new planner, giving it near-optimal downrange and crossrange capabilities. Planned trajectories and guidance simulation results are presented that demonstrate the improved performance. Based on the new planner, a method is developed for approximating the landing footprint for entry vehicles in near real-time, as would be needed for an on-board flight management system. The boundary of the footprint is constructed from the endpoints of extreme downrange and crossrange trajectories generated by the new trajectory planner. The footprint algorithm inherently possesses many of the qualities of the new planner, including quick execution, the ability to accurately approximate the vehicle's glide capabilities, and applicability to a wide range of entry conditions. Footprints can be generated for orbital and suborbital entry conditions using a pre

  20. Advanced Face Gear Surface Durability Evaluations

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Heath, Gregory F.

    2016-01-01

    The surface durability life of helical face gears and isotropic super-finished (ISF) face gears was investigated. Experimental fatigue tests were performed at the NASA Glenn Research Center. Endurance tests were performed on 10 sets of helical face gears in mesh with tapered involute helical pinions, and 10 sets of ISF-enhanced straight face gears in mesh with tapered involute spur pinions. The results were compared to previous tests on straight face gears. The life of the ISF configuration was slightly less than that of previous tests on straight face gears. The life of the ISF configuration was slightly greater than that of the helical configuration.

  1. 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

  2. Radiometric calibration of Advanced Land Imager using reflectance-based results between 2001 and 2005

    NASA Astrophysics Data System (ADS)

    McCorkel, J.; Thome, K.; Biggar, S.; Kuester, M.

    2006-08-01

    The Landsat series of sensors have supplied the remote sensing community with a continuous data set dating to the early 1970s. An important aspect of retaining the continuity of these data is that a Landsat follow-on as well as current Landsat instruments must be understood radiometrically throughout their mission. The Advanced Land Imager (ALI), for example, was developed as a prototype for the next generation of Landsat Instruments, and as such there was a significant effort to understand its radiometric characteristics as well as how it compares with previous Landsat sensors. The Remote Sensing Group at the University of Arizona has been part of this effort since the late 2000 launch of ALI through the use of the reflectance-based method of vicarious calibration. The reflectance-based approach consists of ground-based measurements of atmospheric conditions and surface reflectance at the time of satellite overpass to predict the at-sensor radiance seen by the sensor under study. The work compares results from the reflectance-based approach obtained from well-characterized test sites such as Railroad Valley Playa in Nevada and Ivanpah Playa in California as applied to ALI, Landsat-5 TM, and Landsat-7 EMT+. The results from the comparison use a total of 14 ALI dates spanning in time from 2001 to late 2005 and show that ALI agrees with the current radiometric results from TM and ETM+ to within 5%.

  3. Land Surface Temperature Measurements from EOD MODIS Data

    NASA Technical Reports Server (NTRS)

    Wan, Zheng-Ming

    1998-01-01

    We made more tests of the version 2.0 daily Level 2 and Level 3 Land-Surface Temperature (LST) code (PGE 16) jointly with the MODIS Science Data Support Team (SDST). After making minor changes a few times, the PGE16 code has been successfully integrated and tested by MODIS SDST, and recently has passed the inspection at the Goddard Distributed Active Archive Center (DAAC). We conducted a field campaign in the area of Mono Lake, California on March 10, 1998, in order to validate the MODIS LST algorithm in cold and dry conditions. Two MODIS Airborne Simulator (MAS) flights were completed during the field campaign, one before noon, and another around 10 pm PST. The weather condition for the daytime flight was perfect: clear sky, the column water vapor measured by radiosonde around 0.3 cm, and wind speed less than a half meter per second. The quality of MAS data is good for both day and night flights. We analyzed the noise equivalent temperature difference (NE(delta)T) and the calibration accuracy of the seven MAS thermal infrared (TIR) bands, that are used in the MODIS day/night LST algorithm, with daytime MAS data over four flat homogeneous study areas: two on Grant Lake (covered with ice and snow, respectively), one on Mono Lake, and another on the snow field site where we made field measurements. NE(delta)T ranges from 0.2 to 0.6 k for bands 42, 45, 46, and 48. It ranges from 0.8 to 1.1 K for bands 30-32. The day and night MAS data have been used to retrieve surface temperature and emissivities in these bands. A simple method to correct the effect of night thin cirrus has been incorporated into the day/night LST algorithm in dry atmospheric conditions. We compared the retrieved surface temperatures with those measured with TIR spectrometer, radiometers and thermistors in the snow test site, and the retrieved emissivity images with topographic map. The daytime LST values match well within 1 K. The night LST retrieved from MAS data is 3.3 K colder than those from

  4. Land Surface Temperature Variational Assimilation within the ORCHIDEE Continental Surface model

    NASA Astrophysics Data System (ADS)

    Benavides, Hector Simon; Ottlé, Catherine; Thiria, Sylvie; Brajard, Julien; Bradan, Fouad; Maugis, Pascal

    2014-05-01

    Variational data assimilation of FLUXNET soil surface temperature is applied to the energy and water budgets modules of the ORCHIDEE land surface model. This part of the model, called SECHIBA, describes the exchanges of water and energy between the surface and the atmosphere. The adjoint semi-generator software YAO is used as a framework to implement 4D-VAR assimilation. First, sensitivity analysis was performed in order to validate the adjoint and to identify the most influential parameters. Following, the results of twin experiments using synthetic observations demonstrate the robustness, consistency and flexibility of the process. Rendundant combinations of parameters and insensitive ones can then be detected, thus allowing to document the most efficient set of parameters to calibrate. However, optimal sets of parameter vary with time of day, season, site and initial state, thus suggesting a calibration strategy based on different time windows and sites to help constrain a larger set of parameter than on a single space-time window. Doing so on two FLUXNET sites and including initial soil water content as a parameter improves the model output. Although it proved difficult to characterize at the same time state variables and fluxes, this study puts forward the potential of land surface temperature variational data assimilation in model calibration and prediction errors reduction.

  5. Downscaling MODIS Land Surface Temperature for Urban Public Health Applications

    NASA Technical Reports Server (NTRS)

    Al-Hamdan, Mohammad; Crosson, William; Estes, Maurice, Jr.; Estes, Sue; Quattrochi, Dale; Johnson, Daniel

    2013-01-01

    This study is part of a project funded by the NASA Applied Sciences Public Health Program, which focuses on Earth science applications of remote sensing data for enhancing public health decision-making. Heat related death is currently the number one weather-related killer in the United States. Mortality from these events is expected to increase as a function of climate change. This activity sought to augment current Heat Watch/Warning Systems (HWWS) with NASA remotely sensed data, and models used in conjunction with socioeconomic and heatrelated mortality data. The current HWWS do not take into account intra-urban spatial variation in risk assessment. The purpose of this effort is to evaluate a potential method to improve spatial delineation of risk from extreme heat events in urban environments by integrating sociodemographic risk factors with estimates of land surface temperature (LST) derived from thermal remote sensing data. In order to further improve the consideration of intra-urban variations in risk from extreme heat, we also developed and evaluated a number of spatial statistical techniques for downscaling the 1-km daily MODerate-resolution Imaging Spectroradiometer (MODIS) LST data to 60 m using Landsat-derived LST data, which have finer spatial but coarser temporal resolution than MODIS. In this paper, we will present these techniques, which have been demonstrated and validated for Phoenix, AZ using data from the summers of 2000-2006.

  6. 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.

  7. Human-induced greening of the northern extratropical land surface

    NASA Astrophysics Data System (ADS)

    Mao, Jiafu; Ribes, Aurélien; Yan, Binyan; Shi, Xiaoying; Thornton, Peter E.; Séférian, Roland; Ciais, Philippe; Myneni, Ranga B.; Douville, Hervé; Piao, Shilong; Zhu, Zaichun; Dickinson, Robert E.; Dai, Yongjiu; Ricciuto, Daniel M.; Jin, Mingzhou; Hoffman, Forrest M.; Wang, Bin; Huang, Mengtian; Lian, Xu

    2016-10-01

    Significant land greening in the northern extratropical latitudes (NEL) has been documented through satellite observations during the past three decades. This enhanced vegetation growth has broad implications for surface energy, water and carbon budgets, and ecosystem services across multiple scales. Discernible human impacts on the Earth's climate system have been revealed by using statistical frameworks of detection-attribution. These impacts, however, were not previously identified on the NEL greening signal, owing to the lack of long-term observational records, possible bias of satellite data, different algorithms used to calculate vegetation greenness, and the lack of suitable simulations from coupled Earth system models (ESMs). Here we have overcome these challenges to attribute recent changes in NEL vegetation activity. We used two 30-year-long remote-sensing-based leaf area index (LAI) data sets, simulations from 19 coupled ESMs with interactive vegetation, and a formal detection and attribution algorithm. Our findings reveal that the observed greening record is consistent with an assumption of anthropogenic forcings, where greenhouse gases play a dominant role, but is not consistent with simulations that include only natural forcings and internal climate variability. These results provide the first clear evidence of a discernible human fingerprint on physiological vegetation changes other than phenology and range shifts.

  8. Land surface cleanup of plutonium at the Nevada Test Site

    SciTech Connect

    Ebeling, L.L.; Evans, R.B.; Walsh, E.J.

    1991-01-01

    The Nevada Test Site (NTS) covers approximately 3300 km{sup 2} of high desert and is located approximately 100 km northwest of Las Vegas, Nevada. Soil contaminated by plutonium exists on the NTS and surrounding areas from safety tests conducted in the 1950s and 1960s. About 150 curies of contamination have been measured over 1200 hectares of land surface. Most contamination is found in the top 5 cm of soil but may be found deep as 25 cm. The cost of conventional removal and disposal of the full soil volume has been estimated at over $500,000,000. This study is directed toward minimizing the volume of waste which must be further processed and disposed of by precisely controlling soil removal depth. The following soil removal machines were demonstrated at the NTS: (1) a CMI Corporation Model PR-500FL pavement profiler, (2) a CMI Corporation Model Tr-225B trimmer reclaimer, (3) a Caterpillar Model 623 elevating scraper equipped with laser depth control, (4) a Caterpillar Model 14G motor grader equipped with laser depth control, (5) a Caterpillar Model 637 auger scraper, and (6) a XCR Series Guzzler vacuum truck. 5 refs., 5 figs.

  9. Infiltration of surface mined land reclaimed by deep tillage treatments

    SciTech Connect

    Chong, S.K.; Cowsert, P.

    1994-12-31

    Surface mining of coal leads to the drastic disturbance of soils. Compaction of replaced subsoil and topsoil resulting from hauling, grading, and leveling procedures produces a poor rooting medium for crop growth. Soil compaction results in high bulk density, low macroporosity, poor water infiltration capacity, and reduced elongation of plant roots. In the United States, Public Law 95-87 mandates that the rooting medium of mined soils have specific textural characteristics and be graded and shaped to a topography similar to premining conditions. Also, crop productivity levels equivalent to those prior to mining must be achieved, especially for prime farmland. Alleviation of compaction has been the major focus of reclamation, and recently new techniques to augment the rooting zone with deep-ripping and loosening equipment have come to the forefront. Several surface mine operators in the Illinois coal basin are using deep tillage equipment that is capable of loosening soils to greater depths than is possible with conventional farm tillage equipment. Information on the beneficial effects of these loosening procedures on soil hydrological properties, such as infiltration, runoff potential, erosion, and water retention, is extremely important for future mined land management. However, such information is lacking. In view of the current yield demonstration regulation for prime farmland and other unmined soils, it is important that as much information as possible be obtained concerning the effect of deep tillage on soil hydrologic properties. The objectives of this study are: (1) to compare infiltration rates and related soil physical properties of mined soils reclaimed by various deep tillage treatments and (2) to study the temporal variability of infiltration and related physical properties of the reclaimed mined soil after deep tillage treatment.

  10. Fire disturbance effects on land surface albedo in Alaskan tundra

    NASA Astrophysics Data System (ADS)

    French, Nancy H. F.; Whitley, Matthew A.; Jenkins, Liza K.

    2016-03-01

    The study uses satellite Moderate Resolution Imaging Spectroradiometer albedo products (MCD43A3) to assess changes in albedo at two sites in the treeless tundra region of Alaska, both within the foothills region of the Brooks Range, the 2007 Anaktuvuk River Fire (ARF) and 2012 Kucher Creek Fire (KCF). Results are compared to each other and other studies to assess the magnitude of albedo change and the longevity of impact of fire on land surface albedo. In both sites there was a marked decrease of albedo in the year following the fire. In the ARF, albedo slowly increased until 4 years after the fire, when it returned to albedo values prior to the fire. For the year immediately after the fire, a threefold difference in the shortwave albedo decrease was found between the two sites. ARF showed a 45.3% decrease, while the KCF showed a 14.1% decrease in shortwave albedo, and albedo is more variable in the KCF site than ARF site 1 year after the fire. These differences are possibly the result of differences in burn severity of the two fires, wherein the ARF burned more completely with more contiguous patches of complete burn than KCF. The impact of fire on average growing season (April-September) surface shortwave forcing in the year following fire is estimated to be 13.24 ± 6.52 W m-2 at the ARF site, a forcing comparable to studies in other treeless ecosystems. Comparison to boreal studies and the implications to energy flux are discussed in the context of future increases in fire occurrence and severity in a warming climate.

  11. Satellite assessment of land surface evapotranspiration for the pan-Arctic domain

    NASA Astrophysics Data System (ADS)

    Mu, Qiaozhen; Jones, Lucas A.; Kimball, John S.; McDonald, Kyle C.; Running, Steven W.

    2009-09-01

    Regional evapotranspiration (ET), including water loss from plant transpiration and soil evaporation, is essential to understanding interactions between land-atmosphere surface energy and water balances. Vapor pressure deficit (VPD) and surface air temperature are key variables for stomatal conductance and ET estimation. We developed an algorithm to estimate ET using the Penman-Monteith approach driven by Moderate Resolution Imaging Spectroradiometer (MODIS)-derived vegetation data and daily surface meteorological inputs including incoming solar radiation, air temperature, and VPD. The model was applied using alternate daily meteorological inputs, including (1) site level weather station observations, (2) VPD and air temperature derived from the Advanced Microwave Scanning Radiometer (AMSR-E) on the EOS Aqua satellite, and (3) Global Modeling and Assimilation Office (GMAO) reanalysis meteorology-based surface air temperature, humidity, and solar radiation data. Model performance was assessed across a North American latitudinal transect of six eddy covariance flux towers representing northern temperate grassland, boreal forest, and tundra biomes. Model results derived from the three meteorology data sets agree well with observed tower fluxes (r > 0.7; P < 0.003; root mean square error of latent heat flux <30 W m-2) and capture spatial patterns and seasonal variability in ET. The MODIS-AMSR-E-derived ET results also show similar accuracy to ET results derived from GMAO, while ET estimation error was generally more a function of algorithm parameterization than differences in meteorology drivers. Our results indicate significant potential for regional mapping and monitoring daily land surface ET using synergistic information from satellite optical IR and microwave remote sensing.

  12. Sensitivity of land surface modeling to parameters: An uncertainty quantification method applied to the Community Land Model

    NASA Astrophysics Data System (ADS)

    Ricciuto, D. M.; Mei, R.; Mao, J.; Hoffman, F. M.; Kumar, J.

    2015-12-01

    Uncertainties in land parameters could have important impacts on simulated water and energy fluxes and land surface states, which will consequently affect atmospheric and biogeochemical processes. Therefore, quantification of such parameter uncertainties using a land surface model is the first step towards better understanding of predictive uncertainty in Earth system models. In this study, we applied a random-sampling, high-dimensional model representation (RS-HDMR) method to analyze the sensitivity of simulated photosynthesis, surface energy fluxes and surface hydrological components to selected land parameters in version 4.5 of the Community Land Model (CLM4.5). Because of the large computational expense of conducting ensembles of global gridded model simulations, we used the results of a previous cluster analysis to select one thousand representative land grid cells for simulation. Plant functional type (PFT)-specific uniform prior ranges for land parameters were determined using expert opinion and literature survey, and samples were generated with a quasi-Monte Carlo approach-Sobol sequence. Preliminary analysis of 1024 simulations suggested that four PFT-dependent parameters (including slope of the conductance-photosynthesis relationship, specific leaf area at canopy top, leaf C:N ratio and fraction of leaf N in RuBisco) are the dominant sensitive parameters for photosynthesis, surface energy and water fluxes across most PFTs, but with varying importance rankings. On the other hand, for surface ans sub-surface runoff, PFT-independent parameters, such as the depth-dependent decay factors for runoff, play more important roles than the previous four PFT-dependent parameters. Further analysis by conditioning the results on different seasons and years are being conducted to provide guidance on how climate variability and change might affect such sensitivity. This is the first step toward coupled simulations including biogeochemical processes, atmospheric processes

  13. Practical split-window algorithm for retrieving land surface temperature over agricultural areas from ASTER data

    NASA Astrophysics Data System (ADS)

    Wang, Songhan; He, Longhua

    2014-01-01

    A practical split-window algorithm which involves two parameters (transmittance and emissivity) utilized to retrieve land-surface temperature over agricultural areas from the Advanced Spaceborne Thermal Emission and Reflection Radiometer data is presented. First, by calculating the relationship between thermal radiation intensity and temperature, the Planck function is simplified using exponential function which is applied to deduce the split-window algorithm. Second, how to obtain transmittance from water vapor content and the method for estimating emissivity using normalized difference vegetation index are discussed in detail. Sensitivity analysis demonstrates that the algorithm is not sensitive to these two parameters. Finally, a standard atmospheric simulation method has been used to validate the proposed algorithm, and comparison between the algorithm and the prior study has been carried out. The results indicate that the average accuracy is 0.32 K for the case without error in both transmittance and emissivity, which is better than the prior algorithm. The accuracy is also 0.32 K when the transmittance is computed from the water content by piecewise cubic polynomial fit. The accuracy is about 0.30 K˜0.33 K corresponding to different Pv (Pv is the proportion of vegetation) values, which indicates that this algorithm is suitable for different land surface types over agricultural areas.

  14. Linking Satellite Derived Land Surface Temperature with Cholera: A Case Study for South Sudan

    NASA Astrophysics Data System (ADS)

    Aldaach, H. S. V.; Jutla, A.; Akanda, A. S.; Colwell, R. R.

    2014-12-01

    A sudden onset of cholera in South Sudan, in April 2014 in Northern Bari in Juba town resulted in more than 400 cholera cases after four weeks of initial outbreak with a case of fatality rate of CFR 5.4%. The total number of reported cholera cases for the period of April to July, 2014 were 5,141 including 114 deaths. With the limited efficacy of cholera vaccines, it is necessary to develop mechanisms to predict cholera occurrence and thereafter devise intervention strategies for mitigating impacts of the disease. Hydroclimatic processes, primarily precipitation and air temperature are related to epidemic and episodic outbreak of cholera. However, due to coarse resolution of both datasets, it is not possible to precisely locate the geographical location of disease. Here, using Land Surface Temperature (LST) from MODIS sensors, we have developed an algorithm to identify regions susceptible for cholera. Conditions for occurrence of cholera were detectable at least one month in advance in South Sudan and were statistically sensitive to hydroclimatic anomalies of land surface and air temperature, and precipitation. Our results indicate significant spatial and temporal averaging required to infer usable information from LST over South Sudan. Preliminary results that geographically location of cholera outbreak was identifiable within 1km resolution of the LST data.

  15. Land cover change impacts on surface ozone: an observation-based study

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Lin, Jintai

    2016-04-01

    Ozone air quality is a critical global environmental issue. Although it is clear that industrialization and urbanization has increased surface ozone through enhanced emissions of its precursors, much less is known about the role of changes in land cover and land use. Human activities have substantially altered the global land cover and land use through agriculture, urbanization, deforestation, and afforestation. Changes in Land cover and land use affect the ozone levels by altering soil emissions of nitrogen oxides (NOx), biogenic emissions of volatile organic compounds (VOCs), and dry deposition of ozone itself. This study performs a series of experiments with a chemical transport model based on satellite observation of land types to analyze the influences of changes in land cover/land use and their impact on surface ozone concentration. Our results indicate that land cover change explains 1-2 ppbv of summertime surface ozone increase in the Western United States and 1-6 ppbv of increase in Southern China between 2001 and 2012. This is largely driven by enhanced isoprene emissions and soil NOx emissions. It is also found that land cover change itself elevates summertime surface zone in Canadian coniferous forests by up to 4 ppbv mainly through substantial decreases in ozone dry deposition associated with increased vegetation density in a warmer climate.

  16. DEVELOPMENT OF A LAND-SURFACE MODEL PART I: APPLICATION IN A MESOSCALE METEOROLOGY MODEL

    EPA Science Inventory

    Parameterization of land-surface processes and consideration of surface inhomogeneities are very important to mesoscale meteorological modeling applications, especially those that provide information for air quality modeling. To provide crucial, reliable information on the diurn...

  17. Analysis of the Effects of Different Land Use and Land Cover Classification on Surface Meteorological Variables using WRF Model

    NASA Astrophysics Data System (ADS)

    Sati, A. P.

    2015-12-01

    The continuous population growth and the subsequent economic expansion over centuries have been the primary drivers of land use /land cover (LULC) changes resulting in the environmental changes across the globe. Most of the urban areas being developed today are on the expense of agricultural or barren lands and the changes result from various practices such as deforestation, changing agriculture practices, rapid expansion of urban centers etc.For modeling applications, classification of land use is important and periodic updates of land cover are necessary to capture change due to LULC changes.Updated land cover and land use data derived from satellites offer the possibility of consistent and regularly collected information on LULC. In this study we explore the application of Landsat based LULC classification inWeather Research and Forecasting (WRF) model in predicting the meteorology over Delhi, India. The supervised classification of Landsat 8 imagery over Delhi region is performed which update the urban extent as well as other Land use for the region. WRF model simulations are performed using LULC classification from Landsat data, United States Geological Survey (USGS) and Moderate Resolution Imaging Spectroradiometer (MODIS) for various meteorological parameters. Modifications in LULC showed a significant effect on various surface meteorological parameters such as temperature, humidity, wind circulations and other underlying surface parameters. There is a considerable improvement in the spatial distribution of the surface meteorological parameters with correction in input LULC. The study demonstrates the improved LULC classification from Landsat data than currently in vogue and their potential to improve numerical weather simulations especially for expanding urban areas.The continuous population growth and the subsequent economic expansion over centuries have been the primary drivers of land use /land cover (LULC) changes resulting in the environmental changes

  18. Deriving New Topography-based Global Datasets for Land Surface Modeling

    NASA Astrophysics Data System (ADS)

    Tesfa, T. K.; Leung, L. R.

    2015-12-01

    Topography exerts a major control on land surface processes through its influence on atmospheric forcing, soil and vegetation properties, network topology and drainage area. Land surface spatial structure that captures spatial heterogeneity influenced by topography is expected to improve representation of land surface processes in land surface models. For example, land surface modeling using subbasins instead of regular grids as computational units has demonstrated improved scalability of simulated runoff and streamflow processes. In this study, a local classification method is applied to derive a new land surface spatial structure defined by further dividing subbasins into subgrid units based on elevation, topographic slope and aspect to take advantage of the emergent patterns and scaling properties of atmospheric, hydrologic, and vegetation processes in land surface models. For this purpose, a more consistent 90 meter resolution global surface elevation data has been developed by blending elevation data obtained from various sources. Taking the advantage of natural hydrologic connectivity of watersheds, new subbasin-based river routing and reservoir dependency datasets are being developed to improve representation of the managed hydrologic systems in the Community Land Model.

  19. Analysis of surface energy budget data over varying land-cover conditions.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The surface energy budget plays an important role in boundary-layer meteorology and quantifying these budgets over varying land surface types is important in studying land-atmosphere interactions. In late April 2007, eddy covariance towers were erected at four sites in the Little Washita Watershed i...

  20. Analysis of Surface Energy Budget Data Over Varying Land-Cover Conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The surface energy budget plays an important role in boundary-layer meteorology and quantifying these budgets over varying land surface types is important in studying land-atmosphere interactions. In late April 2007, eddy covariance towers were erected at four sites in the Little Washita Watershed ...

  1. Mapping land-surface fluxes of carbon, water and energy from field to regional scales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A framework for routine mapping of land-surface fluxes of carbon, water, and energy at the field to regional scales has been established for drought monitoring, water resource management, yield forecasting and crop-growth monitoring. The framework uses the ALEXI/DisALEXI suite of land-surface model...

  2. Evaluation of a photosyntheses-based canopy resistance formulation in the Noah Land-surface model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurately representing complex land-surface processes balancing complexity and realism remains one challenge that the weather modelling community is facing nowadays. In this study, a photosynthesis-based Gas-exchange Evapotranspiration Model (GEM) is integrated into the Noah land-surface model repl...

  3. Recent Progresses in Incorporating Human Land-Water Management into Global Land Surface Models Toward Their Integration into Earth System Models

    NASA Technical Reports Server (NTRS)

    Pokhrel, Yadu N.; Hanasaki, Naota; Wada, Yoshihide; Kim, Hyungjun

    2016-01-01

    The global water cycle has been profoundly affected by human land-water management. As the changes in the water cycle on land can affect the functioning of a wide range of biophysical and biogeochemical processes of the Earth system, it is essential to represent human land-water management in Earth system models (ESMs). During the recent past, noteworthy progress has been made in large-scale modeling of human impacts on the water cycle but sufficient advancements have not yet been made in integrating the newly developed schemes into ESMs. This study reviews the progresses made in incorporating human factors in large-scale hydrological models and their integration into ESMs. The study focuses primarily on the recent advancements and existing challenges in incorporating human impacts in global land surface models (LSMs) as a way forward to the development of ESMs with humans as integral components, but a brief review of global hydrological models (GHMs) is also provided. The study begins with the general overview of human impacts on the water cycle. Then, the algorithms currently employed to represent irrigation, reservoir operation, and groundwater pumping are discussed. Next, methodological deficiencies in current modeling approaches and existing challenges are identified. Furthermore, light is shed on the sources of uncertainties associated with model parameterizations, grid resolution, and datasets used for forcing and validation. Finally, representing human land-water management in LSMs is highlighted as an important research direction toward developing integrated models using ESM frameworks for the holistic study of human-water interactions within the Earths system.

  4. 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

  5. Comparing Methods for Land Surface Temperature Retrieval over Heterogeneous Land Cover Using Landsat-5 TM Thermal Infrared Data

    NASA Astrophysics Data System (ADS)

    Windahl, E.; de Beurs, K.

    2014-12-01

    Among other applications, remotely sensed land surface temperature (LST) has become critical for monitoring the surface urban heat island (SUHI) effect in cities across the world. While daily MODIS thermal infrared data is invaluable for examining changes in LST over time, the large 1 km spatial resolution makes studying the spatial patterns of LST in a heterogeneous urban environment difficult. The 120 m spatial resolution of Landsat 4-5 TM, as well the archive of data stretching back to 1982, make Landsat 4-5 TM sensors valuable resources for thermal data, especially in urban areas. However, the difficulty accurately correcting for atmospheric effects with only one thermal band, as well as the necessity for a priori knowledge of land surface emissivity (LSE), mean it is underutilized. Research to determine best practices for deriving LST from Landsat TM data given homogenous, usually vegetated land cover is relatively extensive; however, the accuracy of these methods given heterogeneous land cover is less well known, especially given Land Surface Emissivity (LSE) calculations that often rely heavily on NDVI. In order to determine the best methodology for measuring LST across heterogeneous land cover in the central United States, this study derives LST from Landsat 5 TM band 6 for Oklahoma City and the surrounding countryside on a fall and a spring date using three different methods: no atmospheric correction, the radiative transfer equation, and the mono-window algorithm. With all three methods, the common NDVI-based approach for estimating LSE is used; a fourth LST calculation with no atmospheric correction and an assumed emissivity of one is therefore included as contrast. Using regression analysis, these four LST measurements are compared to air temperatures recorded concurrently by approximately 40 Oklahoma Mesonet stations across the study area, and results are broken down by land cover type to explore potential biases or variations in accuracy.

  6. Distributions of surface-layer buoyance versus lifting condensation level over a heterogeneous land surface

    SciTech Connect

    Schrieber, K.; Zhang, Qing; Stull, R.

    1996-04-15

    Onset and coverage of small cumulus clouds depend on the relative abundance of surface-layer air parcels possessing favorable buoyancy and moisture - two variables that are coupled through the surface energy budget. This abundance is described using a joint frequency distribution (JFD) as a function of virtual potential temperature {theta}{sub v} and height of the lifting condensation level z{sub LCL}. It is shown analytically that the shape and spread of this JFD depends on the ranges of Bowen ratios and solar forcings (albedoes, cloud shading, etc.) that exist within a domain of heterogeneous land use. To sample the character of such JFDs in the real atmosphere, a case study is presented using turbulence data gathered by aircraft flying in the surface layer of southwest France. This case study includes 4 days of clear skies during the Hydrologic Atmospheric Pilot Experiment (HAPEX) of 1986. The full flight track during HAPEX overflew a wide range of land use including evergreen forest, corn, vineyards, pastures, and irrigated fields over varied topography. The JFDs from these full tracks are found to be quite complex, being frequently multimodal with a convoluted perimeter. However, when a full track is broken into segments, each over a subdomain of quasi-homogeneous land use, the resulting segment JFDs are mono-modal with simpler topology. Such a characterization of JFDs provides guidance toward eventual subgrid cumulus parameterization in large-scale forecast models, with associated impacts in aviation forecasting, pollutant venting and chemical reactions, verticle dispersion and turbulence modulation, and radiation balance in climate-change models. 48 refs., 17 figs., 7 tabs.

  7. Comprehensive Assessment of Land Surface, Snow, and Soil Moisture-Climate Feedbacks by Multi-model Experiments of Land Surface Models under LS3MIP

    NASA Astrophysics Data System (ADS)

    Oki, T.; Kim, H.; Hurk, B. V. D.; Krinner, G.; Derksen, C.; Seneviratne, S. I.

    2015-12-01

    The solid and liquid water stored at the land surface has a large influence on the regional climate, its variability and its predictability, including effects on the energy and carbon cycles. Notably, snow and soil moisture affect surface radiation and flux partitioning properties, moisture storage and land surface memory. The Land surface, snow and soil moisture model inter-comparison project (LS3MIP) experiments address together the following objectives: an evaluation of the current state of land processes including surface fluxes, snow cover and soil moisture representation in CMIP6 DECK runs (LMIP-protoDECK) a multi-model estimation of the long-term terrestrial energy/water/carbon cycles, using the surface modules of CMIP6 models under observation constrained historical (land reanalysis) and projected future (impact assessment) conditions considering land use/land cover changes. (LMIP) an assessment of the role of snow and soil moisture feedbacks in the regional response to altered climate forcings, focusing on controls of climate extremes, water availability and high-latitude climate in historical and future scenario runs (LFMIP) an assessment of the contribution of land surface processes to the current and future predictability of regional temperature/precipitation patterns. (LFMIP) These LS3MIP outcomes will contribute to the improvement of climate change projections by reducing the systematic biases from the land surface component of climate models, and a better representation of feedback mechanisms related to snow and soil moisture in climate models. Further, LS3MIP will enable the assessment of probable historical changes in energy, water, and carbon cycles over land surfaces extending more than 100 years, including spatial variability and trends in global runoff, snow cover, and soil moisture that are hard to detect purely based on observations. LS3MIP will also enable the impact assessments of climate changes on hydrological regimes and available

  8. Coal surface control for advanced physical fine coal cleaning technologies

    SciTech Connect

    Morsi, B.I.; Chiang, S.H.; Sharkey, A.; Blachere, J.; Klinzing, G.; Araujo, G.; Bi, H.; Campbell, P.; Ciocco, M.; Hittle, L.; Kim, S.; Kim, Y.

    1991-01-01

    The overall objective of the project is to develop techniques for coal surface control prior to the advanced physical fine coal cleaning process of selective agglomeration in order to achieve 90% pyrite sulfur rejection at an energy recovery greater than 90% based on run-of-mine coal. The surface control is meant to encompass surface modification during grinding and laboratory beneficiation testing. The project includes the following tasks: Project planning, method for analysis of samples, development of standard beneficiation test, grinding studies, modification of particle surface, and exploratory R D and support. 5 refs., 22 figs., 34 tabs.

  9. Land-Use Change and Earth System Dynamics: Advancing the Science

    NASA Astrophysics Data System (ADS)

    Hurtt, George

    2010-05-01

    Quantifying the effects of land-use changes on Earth system dynamics requires adequate information on both past and future land-use activities in a format appropriate for models capable of tracking relevant impacts. This presentation will review past approaches to understanding the role of land-use change on the Earth system dynamics, and summarize new work involving ‘land-use harmonization' (Hurtt et al. 2009) to advance the understanding for IPCC-AR5 and beyond. Emphasis will be placed on the importance and accuracy of historical maps, uncertainties in future projections, and key challenges for the future. Hurtt, G. C., L. P. Chini, S. Frolking, R. Betts, J. Feedema, G. Fischer, K. Klein Goldewijk, K. Hibbard, A. Janetos, C. Jones, G. Kindermann, T. Kinoshita, K. Riahi, E. Shevliakova, S. Smith, E. Stehfest, A. Thomson, P. Thorton, D. van Vuuren, Y. Wang (2009), Harmonization of Global Land-Use Scenarios for the Period 1500-2100 for IPCC-AR5. Integrated Land Ecosystem-Atmosphere Processes Study (iLEAPS) Newsletter 7:6-8.

  10. LOTOS: A Proposed Lower Tropospheric Observing System from the Land Surface through the Atmospheric Boundary Layer

    NASA Astrophysics Data System (ADS)

    Cohn, S. A.; Lee, W. C.; Carbone, R. E.; Oncley, S.; Brown, W. O. J.; Spuler, S.; Horst, T. W.

    2015-12-01

    Advances in sensor capabilities, but also in electronics, optics, RF communication, and off-the-grid power are enabling new measurement paradigms. NCAR's Earth Observing Laboratory (EOL) is considering new sensors, new deployment modes, and integrated observing strategies to address challenges in understanding within the atmospheric boundary layer and the underlying coupling to the land surface. Our vision is of a network of deployable observing sites, each with a suite of complementary instruments that measure surface-atmosphere exchange, and the state and evolution of the boundary layer. EOL has made good progress on distributed surface energy balance and flux stations, and on boundary layer remote sensing of wind and water vapor, all suitable for deployments of combined instruments and as network of such sites. We will present the status of the CentNet surface network development, the 449-MHz modular wind profiler, and a water vapor and temperature profiling differential absorption lidar (DIAL) under development. We will further present a concept for a test bed to better understand the value of these and other possible instruments in forming an instrument suite flexible for multiple research purposes.

  11. Estimation of Land Surface Temperature from 1-km AVHRR data

    NASA Astrophysics Data System (ADS)

    Frey, Corinne

    2016-04-01

    In order to re-process DLRs 1km AVHRR data archive to different geophysical and descriptive parameters of the land surface and the atmosphere, a series of scientific data processors are being developed in the framework of the TIMELINE project. The archive of DLR ranges back to the 80ies. One of the data processors is SurfTemp, which processes L2 LST and emissivity datasets from AVHRR L1b data. The development of the data processor included the selection of statistical procedures suitable for time series processing, including four mono-window and six split window algorithms. For almost all of these algorithms, new constants were generated, which better account for different atmospheric and geometric acquisition situations. The selection of optimal algorithms for SurfTemp is based on a round robin approach, in which the selected mono-window and split window algorithms are tested on the basis of a large number of TOA radiance/LST pairs, which were generated using a radiative transfer model and the SeeBorV5 profile database. The original LSTs are thereby compared to the LSTs derived from the TOA radiances using the mono- and split window algorithms. The algorithm comparison includes measures of precision, as well as the sensitivity of a method to the accuracy of its input data. The results of the round robin are presented, as well as the implementation of selected algorithms into SurfTemp. Further, first cross-validation results between the AVHRR LST and MODIS LST are shown.

  12. Estimating land surface heat flux using radiometric surface temperature without the need for an extra resistance

    NASA Astrophysics Data System (ADS)

    Su, H.; Yang, Y.; Liu, S.

    2015-12-01

    Remotely-sensed land surface temperature (LST) is a key variable in energy balance and is widely used for estimating regional heat flux. However, the inequality between LST and aerodynamic surface temperature (Taero) poses a great challenge for regional heat flux estimation in one -source energy balance models. In this study, a one-source model for land (OSML) was proposed to estimate regional surface heat flux without a need for an empirical extra resistance. The proposed OSML employs both a conceptual VFC/LST trapezoid model and the electrical analogue formula of sensible heat flux (H) to estimate the radiometric-convective resistance (rae) by using a quartic equation. To evaluate the performance of OSML, the model was applied to the Soil Moisture-Atmosphere Coupling Experiment (SMACEX), using a remotely-sensed data set at a regional scale. Validated against tower observations, the root mean square deviation (RMSD) of H and latent heat flux (LE) from OSML was 47 W/m2 and 51 W/m2, which is comparable to other published studies. OSML and SEBS (Surface Energy Balance System) compared under the same available energy indicated that LE estimated by OSML is comparable to that derived from the SEBS model. In conducting further inter-comparisons of rae, the aerodynamic resistance derived from SEBS (ra_SEBS), and aerodynamic resistance (ra) derived from Brutsaert et al. (2005) in corn and soybean fields, we found that rae and ra_SEBS are comparable. Most importantly, our study indicates that the OSML method is applicable without having to acquire wind speed or to specify aerodynamic surface characteristics and that it is applicable to heterogeneous areas.

  13. Effects of land use/cover change on land surface energy partitioning and climate in Northeast China

    NASA Astrophysics Data System (ADS)

    Liu, Fengshan; Tao, Fulu; Liu, Jiyuan; Zhang, Shuai; Xiao, Dengpan; Wang, Meng; Zhang, He; Bai, Huizi

    2016-01-01

    The Simple Biosphere Model (SiB2) and the 2 × 2 km resolution National Land use/Land Cover database were used to investigate the effects of Land Use/Cover Change (LUCC) on land surface energy balance and climate in Jilin Province, northeast China, from 1990 to 2005. The spatial patterns of the components of surface energy balance (i.e., net radiation ( R n), latent heat (LH), sensible heat (SH), and albedo ( α)) and climate (i.e., canopy temperature ( T c), diurnal temperature range (DTR)), as well as the roles of land cover type in variations of energy balance and climate, were investigated. The results showed that there were general similar trends in R n, LH, SH, and α in the LUCC process. The spatial patterns of T c and DTR also showed consistent relationships with LUCC processes. Leaf area index (LAI) and canopy conductance ( g c) were found to be the key factors in controlling the spatial patterns of the components of surface energy balance and T c. Using linear correlation method, the gaps of the components of surface energy balance were well-explained by the differences of LAI and g c, and R n had a better correlation with T c and DTR, in the process of LUCC. The surface energy partitioning of R n into LH and SH could not only dampen or strengthen the temperature difference, but also change the relative size of albedo-based R n when the albedo gap was small, between land cover types.

  14. The Impact of the Parcel-Level Land Architecture on Land Surface Temperature in the Phoenix Metropolitan Area

    NASA Astrophysics Data System (ADS)

    LI, X.; Ouyang, Y.; Turner, B. L., II; Harlan, S.; Brazel, A.

    2014-12-01

    The relationship between land surface temperature (LST) and characteristics of the urban land system has received increasing attention in urban heat island research, especially for desert cities. The relationship between the land composition and LST has been widely studied. Such researches generally employ medium or coarser spatial resolution remotely sensed data and primarily focuses on the effects of one land cover type on the LST. In this study, we explore the effects of land system architecture - composition and configuration of different land-cover classes - on LST in the central Arizona-Phoenix metropolitan area at a fine-scale resolution, focused on the composition and configuration of single family residential parcels. A 1 m resolution land-cover map is used to calculate landscape metrics at the parcel level, and 6.8 m resolution data from the MODIS/ASTER are employed to retrieve LST. We introduce the socio-economic factors at neighborhood level as explanatory variables to help control for potential neighborhood effects. Multiple linear regression models examine the effects of landscape configuration on LST at the parcel scale, controlling for the effects of landscape composition and neighborhood characteristics. Results show that the configuration of parcels affects LST, revealing significant variable relationships between that architecture and LST at nighttime and daytime, and the role of the neighborhood effects on the outcomes.

  15. Results from Assimilating AMSR-E Soil Moisture Estimates into a Land Surface Model Using an Ensemble Kalman Filter in the Land Information System

    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)

  16. Advanced surface paneling method for subsonic and supersonic flow

    NASA Technical Reports Server (NTRS)

    Erickson, L. L.; Johnson, F. T.; Ehlers, F. E.

    1976-01-01

    Numerical results illustrating the capabilities of an advanced aerodynamic surface paneling method are presented. The method is applicable to both subsonic and supersonic flow, as represented by linearized potential flow theory. The method is based on linearly varying sources and quadratically varying doublets which are distributed over flat or curved panels. These panels are applied to the true surface geometry of arbitrarily shaped three dimensional aerodynamic configurations.

  17. Estimates of land surface heat fluxes of the Mt. Everest region over the Tibetan Plateau utilizing ASTER data

    NASA Astrophysics Data System (ADS)

    Han, Cunbo; Ma, Yaoming; Chen, Xuelong; Su, Zhongbo

    2016-02-01

    Regional land surface albedo, land surface temperature, net radiation flux, ground heat flux, sensible heat flux, and latent heat flux were derived in the Mt. Everest area utilizing topographical enhanced surface energy balance system (TESEBS) model and nine scenes of ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) data under clear-sky and in-situ measurements at the QOMS station (the Qomolangma Station for Atmospheric Environmental Observation and Research, Chinese Academy of Sciences). The parameterization schemes for diffused and reflected downward shortwave radiation flux of the TESEBS model were improved by introducing the parameters sky-view factor (SVF) and terrain configuration factor (Ct). Then, a so-called C-correction method for land surface albedo was coupled into the TESEBS model to reduce the influences of topography. After topographical correction, the albedo of the dark tilted surface facing away from the Sun was compensated and albedo of the brightness surface facing the Sun was restrained. The downward shortwave radiation flux was broken down into three components including solar direct radiation flux, solar diffused radiation flux, and reflected solar radiation flux by surrounding terrain. The solar diffused radiation flux ranges from about 30 to 60 W/m2 at the satellite passing time on 6 January 2008. The reflected solar radiation flux changes from 0 to more than 100 W/m2 in the area covered by glaciers and snows. Thus, it is important to take the topographical effects into account in estimation of surface radiation balance in the mountainous area, especially in the glacier area. The retrieved land surface parameters, land surface radiation balance components, and the land surface energy balance components were evaluated by the field measurements in the QOMS station. The estimated results were very close to the in-situ observations with low mean bias errors, low root mean square errors and high correlation coefficients

  18. The challenges of designing a lightweight spacecraft structure for landing on the lunar surface

    NASA Astrophysics Data System (ADS)

    Cole, Timothy J.; Bassler, Julie; Cooper, Scott; Stephens, Vince; Ponnusamy, Devamanohar; Briere, Marc; Betenbaugh, Theresa

    2012-02-01

    The Johns Hopkins University Applied Physics Laboratory (JHU/APL) has been working with NASA's Marshall Space Flight Center (MSFC) on a lunar lander design that would take scientific measurements on the surface of the moon. This effort is part of NASA's Robotic Lunar Lander (RLL) Development Project. The requirements imposed on the design of the lander are: (1) Provide a lightweight lander structure to minimize the launch costs and maximize the payload carrying capability, (2) Minimize the lander launch envelope to allow for launching multiple landers on a single launch vehicle, (3) Given specific approach velocities, design a lander with geometric properties (low center-of-gravity, etc.) that maximizes the chances for a controlled landing on the lunar surface, (4) Provide a stable platform for all of the various scientific instruments.The lightweight lander requirement originates from the desire to minimize the launch costs and possibly package multiple landers on a single launch vehicle. The use of lightweight composite materials and advanced manufacturing techniques are employed throughout the design and construction of the structure in order to minimize mass and maximize structural stiffness.Minimizing the launch envelope enables the potential packaging of several spacecraft into one launch vehicle shroud. By having multiple landers, the scientific return is enhanced. Multiple spacecraft on the lunar surface provides independent confirmation of science measurements taken and also highlights any variance in the science data taken at differing lunar latitudes. Naturally, the launch cost per lander is greatly reduced if more than one lander can be packaged on a single launch vehicle.The lunar lander vehicle must arrive at the lunar surface at an upright orientation. In order to accomplish this, the structure geometry must be designed to accommodate attitude errors in roll, pitch and yaw. In addition, the structure must be able to withstand various landing

  19. Improving HJ-1B IRS land surface temperature product using ASTER global emissivity database

    NASA Astrophysics Data System (ADS)

    Li, H.; Hu, T.; Meng, X.; Yongming, D.; Cao, B.; Liu, Q.

    2015-12-01

    Land surface temperature (LST) is a key parameter for hydrological, meteorological, climatological and environmental studies. Currently many operational LST products have been generated using European and American satellite data, i.e., the Advanced Very High Resolution Radiometer (AVHRR), Advanced Along-Track Scanning Radiometer (AATSR) and Moderate Resolution Imaging Spectroradiometer (MODIS). However, few LST product has been produced using Chinese satellite data. Thus, the objective of this study is to generate reliable LST product using Chinese HJ-1B satellite data. The HJ-1B satellite of China, were launched on September 6, 2008, which are used for disaster and environment monitoring. IRS (Infrared Scanner) is one of the key instruments onboard HJ-1B satellite, it can scan the earth every four days, has four spectral bands ranging from the near-infrared to thermal infrared bands (band 1 0.75 - 1.10μm, band 2 1.55-1.75μm, MIR band 3 3.50 - 3.90μm, band 4 10.5-12.5μm) with 720 km swath. It scans ±29° from nadir and the spatial resolution for band1-3 is 150m and 300m for band4. In this study, a single-channel parametric model (SC-PM) algorithm were used to produce 300m LST product from HJ-1B IRS data. The NCEP atmospheric profiles and a parametric model were used for atmospheric correction. In order to improve the accuracy of the land surface emissivity (LSE), the 1km ASTER Global Emissivity Database (GED) and self-developed 5-day 1km vegetation cover product were used for estimating the LSE based on the Vegetation Cover Method. Two years of HJ-1B IRS LST product in Heihe River basin (Gansu province, China) from June 2012 to June 2014 were generated. The LST products were evaluated against ground observations in an arid area of northwest China during the Heihe Watershed Allied Telemetry Experimental Research (HiWATER) experiment. Four barren surface sites and ten vegetated sites were chosen for the evaluation. The results show that the developed HJ-1B IRS

  20. The effects of land surface process perturbations in a global ensemble forecast system

    NASA Astrophysics Data System (ADS)

    Deng, Guo; Zhu, Yuejian; Gong, Jiandong; Chen, Dehui; Wobus, Richard; Zhang, Zhe

    2016-10-01

    Atmospheric variability is driven not only by internal dynamics, but also by external forcing, such as soil states, SST, snow, sea-ice cover, and so on. To investigate the forecast uncertainties and effects of land surface processes on numerical weather prediction, we added modules to perturb soil moisture and soil temperature into NCEP's Global Ensemble Forecast System (GEFS), and compared the results of a set of experiments involving different configurations of land surface and atmospheric perturbation. It was found that uncertainties in different soil layers varied due to the multiple timescales of interactions between land surface and atmospheric processes. Perturbations of the soil moisture and soil temperature at the land surface changed sensible and latent heat flux obviously, as compared to the less or indirect land surface perturbation experiment from the day-to-day forecasts. Soil state perturbations led to greater variation in surface heat fluxes that transferred to the upper troposphere, thus reflecting interactions and the response to atmospheric external forcing. Various verification scores were calculated in this study. The results indicated that taking the uncertainties of land surface processes into account in GEFS could contribute a slight improvement in forecast skill in terms of resolution and reliability, a noticeable reduction in forecast error, as well as an increase in ensemble spread in an under-dispersive system. This paper provides a preliminary evaluation of the effects of land surface processes on predictability. Further research using more complex and suitable methods is needed to fully explore our understanding in this area.

  1. Recent developments in the reclamation of surface mined lands

    USGS Publications Warehouse

    Sharma, K.D.; Gough, L.P.; Kumar, S.; Sharma, B.K.; Saxena, S.K.

    1997-01-01

    A broad review of mine land reclamation problems and challenges in arid lands is presented with special emphasis on work recently completed in India. The economics of mining in the Indian Desert is second only to agriculture in importance. Lands disturbed by mining, however, have only recently been the focus of reclamation attempts. Studies were made and results compiled of problems associated with germplasm selection, soil, plant and overburden characterization and manipulation, plant establishment methods utilized, soil amendment needs, use and conservation of available water and the evaluation of ecosystem sustainability. Emphasis is made of the need for multi-disciplinary approaches to mine land reclamation research and for the long-term monitoring of reclamation success.

  2. Influence of Heterogeneous Land Surfaces on the Surface Energy Budget at - and Large Scales

    NASA Astrophysics Data System (ADS)

    Song, Jie

    1995-11-01

    Discrepancies in temperature and precipitation --between model simulations and observations--have prompted investigators to examine the effects of the subgrid-scale surface variations on climate simulations. The results of the First ISLSCP Field Experiment (FIFE), which was designed to address the scaling up issue through the simultaneous acquisition of satellite, atmospheric, and surface micrometeorological data, is compared to model results. Using a three-dimensional soil-plant-atmosphere mesoscale model and FIFE data, the surface energy fluxes over the FIFE domain have been simulated and compared with measurements. Biophysical processes over the FIFE prairie site play a dominant role in evapotranspiration. The standing brown canopy also appears to be as important as the green canopy. Surface conditions, such as soil moisture availability and vegetation, determine the division of available energy between the land surface and the atmosphere. They also control the partitioning of latent and sensible heat fluxes, and consequently the turbulent exchanges of heat and moisture in the atmospheric boundary layer. Model-simulated surface energy fluxes over the FIFE domain are compared under plausible heterogeneous and homogeneous initial and boundary conditions. Simulated latent heat fluxes are approximately 30 to 40 W m ^{-2} higher and the air temperature is ~eq0.4^circC lower (at noon) when the landsurface is homogeneous. The planetary boundary lazer (PBL) height and turbulent exchanges are lower as well--even though the heterogeneous canopy and soil conditions are only moderately variable in comparison with many landscapes. Further analysis of the influence of heterogeneous land surfaces on the surface energy budget (at GCM scales) was made by randomly prescribing soil-moisture fields that varied from 10% to 100% of soil water-holding capacity. Significant reductions were found in model-simulated average evapotranspiration fields when the initial soil -moisture fields

  3. Satellite Based Mapping of Land Surface ET using MODIS and Alternate Surface Meteorological Inputs from AMSR-E, Reanalysis, and Surface Weather Stations

    NASA Astrophysics Data System (ADS)

    Mu, Q.; Jones, L. A.; Kimball, J. S.; Running, S. W.

    2007-12-01

    Regional evapotranspiration (ET), including water loss from plant transpiration and soil evaporation, is essential to understanding interactions between land-atmosphere surface energy and water balances. Vapor pressure deficit (VPD) and surface air temperature are key variables for stomatal conductance and ET estimation. We developed an algorithm to estimate ET using a modified Penman-Monteith approach driven by MODIS derived vegetation data and daily surface meteorological inputs including net incoming solar radiation, air temperature and VPD. The model was applied using alternate daily meteorological inputs, including: 1) site level weather station observations, 2) VPD and air temperature derived from the Advanced Microwave Scanning Radiometer (AMSR-E) on the EOS Aqua satellite, and 3) Global Modeling and Assimilation Office (GMAO) reanalysis based surface temperature, humidity and solar radiation data. Model performance was assessed across a North American boreal-Arctic transect (>50o N) of six eddy covariance flux towers representing boreal grassland, boreal forest and tundra biomes. Model results derived from the three meteorology data sets agree well with observed tower fluxes (r>0.6; P<0.00001; RMSE<30W/m2) and capture spatial patterns and seasonal variability in ET. The MODIS-AMSR-E derived ET results also show comparable accuracy to ET results derived from the reanalysis meteorology, while ET estimation error was generally more a function of algorithm parameterization than differences in meteorology drivers. Our results indicate significant potential for regional mapping and monitoring daily land surface evaporation using synergistic information from satellite optical-IR and microwave remote sensing.

  4. Determination of Optimum Viewing Angles for the Angular Normalization of Land Surface Temperature over Vegetated Surface

    PubMed Central

    Ren, Huazhong; Yan, Guangjian; Liu, Rongyuan; Li, Zhao-Liang; Qin, Qiming; Nerry, Françoise; Liu, Qiang

    2015-01-01

    Multi-angular observation of land surface thermal radiation is considered to be a promising method of performing the angular normalization of land surface temperature (LST) retrieved from remote sensing data. This paper focuses on an investigation of the minimum requirements of viewing angles to perform such normalizations on LST. The normally kernel-driven bi-directional reflectance distribution function (BRDF) is first extended to the thermal infrared (TIR) domain as TIR-BRDF model, and its uncertainty is shown to be less than 0.3 K when used to fit the hemispheric directional thermal radiation. A local optimum three-angle combination is found and verified using the TIR-BRDF model based on two patterns: the single-point pattern and the linear-array pattern. The TIR-BRDF is applied to an airborne multi-angular dataset to retrieve LST at nadir (Te-nadir) from different viewing directions, and the results show that this model can obtain reliable Te-nadir from 3 to 4 directional observations with large angle intervals, thus corresponding to large temperature angular variations. The Te-nadir is generally larger than temperature of the slant direction, with a difference of approximately 0.5~2.0 K for vegetated pixels and up to several Kelvins for non-vegetated pixels. The findings of this paper will facilitate the future development of multi-angular thermal infrared sensors. PMID:25825975

  5. Determination of optimum viewing angles for the angular normalization of land surface temperature over vegetated surface.

    PubMed

    Ren, Huazhong; Yan, Guangjian; Liu, Rongyuan; Li, Zhao-Liang; Qin, Qiming; Nerry, Françoise; Liu, Qiang

    2015-03-27

    Multi-angular observation of land surface thermal radiation is considered to be a promising method of performing the angular normalization of land surface temperature (LST) retrieved from remote sensing data. This paper focuses on an investigation of the minimum requirements of viewing angles to perform such normalizations on LST. The normally kernel-driven bi-directional reflectance distribution function (BRDF) is first extended to the thermal infrared (TIR) domain as TIR-BRDF model, and its uncertainty is shown to be less than 0.3 K when used to fit the hemispheric directional thermal radiation. A local optimum three-angle combination is found and verified using the TIR-BRDF model based on two patterns: the single-point pattern and the linear-array pattern. The TIR-BRDF is applied to an airborne multi-angular dataset to retrieve LST at nadir (Te-nadir) from different viewing directions, and the results show that this model can obtain reliable Te-nadir from 3 to 4 directional observations with large angle intervals, thus corresponding to large temperature angular variations. The Te-nadir is generally larger than temperature of the slant direction, with a difference of approximately 0.5~2.0 K for vegetated pixels and up to several Kelvins for non-vegetated pixels. The findings of this paper will facilitate the future development of multi-angular thermal infrared sensors.

  6. Use of satellite land surface temperatures in the EUSTACE global surface air temperature analysis

    NASA Astrophysics Data System (ADS)

    Ghent, D.; Good, E.; Rayner, N. A.

    2015-12-01

    EUSTACE (EU Surface Temperatures for All Corners of Earth) is a Horizon2020 project that will produce a spatially complete, near-surface air temperature (NSAT) analysis for the globe for every day since 1850. The analysis will be based on both satellite and in situ surface temperature observations over land, sea, ice and lakes, which will be combined using state-of-the-art statistical methods. The use of satellite data will enable the EUSTACE analysis to offer improved estimates of NSAT in regions that are poorly observed in situ, compared with existing in-situ based analyses. This presentation illustrates how satellite land surface temperature (LST) data - sourced from the European Space Agency (ESA) Data User Element (DUE) GlobTemperature project - will be used in EUSTACE. Satellite LSTs represent the temperature of the Earth's skin, which can differ from the corresponding NSAT by several degrees or more, particularly during the hottest part of the day. Therefore the first challenge is to develop an approach to estimate global NSAT from satellite observations. Two methods will be trialled in EUSTACE, both of which are summarised here: an established empirical regression-based approach for predicting NSAT from satellite data, and a new method whereby NSAT is calculated from LST and other parameters using a physics-based model. The second challenge is in estimating the uncertainties for the satellite NSAT estimates, which will determine how these data are used in the final blended satellite-in situ analysis. This is also important as a key component of EUSTACE is in delivering accurate uncertainty information to users. An overview of the methods to estimate the satellite NSATs is also included in this presentation.

  7. 30 CFR 762.15 - Exploration on land designated as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for surface coal mining operations. 762.15 Section 762.15 Mineral Resources OFFICE OF SURFACE MINING... AREAS AS UNSUITABLE FOR SURFACE COAL MINING OPERATIONS § 762.15 Exploration on land designated as unsuitable for surface coal mining operations. Designation of any area as unsuitable for all or certain...

  8. 30 CFR 762.15 - Exploration on land designated as unsuitable for surface coal mining operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for surface coal mining operations. 762.15 Section 762.15 Mineral Resources OFFICE OF SURFACE MINING... AREAS AS UNSUITABLE FOR SURFACE COAL MINING OPERATIONS § 762.15 Exploration on land designated as unsuitable for surface coal mining operations. Designation of any area as unsuitable for all or certain...

  9. Chemical dynamics simulations of energy transfer, surface-induced dissociation, soft-landing, and reactive-landing in collisions of protonated peptide ions with organic surfaces.

    PubMed

    Pratihar, Subha; Barnes, George L; Hase, William L

    2016-07-01

    There are two components to the review presented here regarding simulations of collisions of protonated peptide ions peptide-H(+) with organic surfaces. One is a detailed description of the classical trajectory chemical dynamics simulation methodology. Different simulation approaches are used, and identified as MM, QM + MM, and QM/MM dependent on the potential energy surface used to represent the peptide-H(+) + surface collision. The second are representative examples of the information that may be obtained from the simulations regarding energy transfer and peptide-H(+) surface-induced dissociation, soft-landing, and reactive-landing for the peptide-H(+) + surface collisions. Good agreement with experiment is obtained for each of these four collision properties. The simulations provide atomistic interpretations of the peptide-H(+) + surface collision dynamics. PMID:26563571

  10. Water balance in the Amazon basin from a land surface model ensemble

    SciTech Connect

    Getirana, Augusto; Dutra, Emanuel; Guimberteau, Matthieu; Kam, Jonghun; Li, Hongyi; Decharme, Bertrand; Zhang, Zhengqiu J.; Ducharne, Agnes; Boone, Aaron; Balsamo, Gianpaolo; Rodell, Matthew; Mounirou Toure, Ally; Xue, Yongkang; Peters-Lidard, Christa D.; Kumar, Sujay V.; Arsenault, Kristi Rae; Drapeau, Guillaume; Leung, Lai-Yung R.; Ronchail, Josyane; Sheffield, Justin

    2014-12-06

    Despite recent advances in modeling and remote sensing of land surfaces, estimates of the global water budget are still fairly uncertain. The objective of this study is to evaluate the water budget of the Amazon basin based on several state-of-the-art land surface model (LSM) outputs. Water budget variables [total water storage (TWS), evapotranspiration (ET), surface runoff (R) and baseflow (B)] are evaluated at the basin scale using both remote sensing and in situ data. Fourteen LSMs were run using meteorological forcings at a 3-hourly time step and 1-degree spatial resolution. Three experiments are performed using precipitation which has been rescaled to match monthly global GPCP and GPCC datasets and the daily HYBAM dataset for the Amazon basin. R and B are used to force the Hydrological Modeling and Analysis Platform (HyMAP) river routing scheme and simulated discharges are compared against observations at 165 gauges. Simulated ET and TWS are compared against FLUXNET and MOD16A2 evapotranspiration, and GRACE TWS estimates in different catchments. At the basin scale, simulated ET ranges from 2.39mm.d-1 to 3.26mm.d-1 and a low spatial correlation between ET and P indicates that evapotranspiration does not depend on water availability over most of the basin. Results also show that other simulated water budget variables vary significantly as a function of both the LSM and precipitation used, but simulated TWS generally agree at the basin scale. The best water budget simulations resulted from experiments using the HYBAM dataset, mostly explained by a denser rainfall gauge network the daily rescaling.

  11. The global land surface energy balance and its representation in CMIP5 models

    NASA Astrophysics Data System (ADS)

    Wild, Martin; Folini, Doris; Hakuba, Maria; Schär, Christoph; Seneviratne, Sonia; Kato, Seiji; Rutan, David; Ammann, Christof; Wood, Eric; König-Langlo, Gert

    2015-04-01

    The energy budget over terrestrial surfaces is a key determinant of the land surface climate and governs a variety of physical, chemical and biological surface processes. The purpose of the present study is to establish new reference estimates for the different components of the energy balance over global land surfaces. Thanks to the impressive progress in space-based observation systems in the past decade, we now know the energy exchanges between our planet and the surrounding space with unprecedented accuracy. However, the energy flows at the Earth's surface have not been established with the same accuracy, since they cannot be directly measured from satellites. Accordingly, estimates on the magnitude of the fluxes at terrestrial surfaces largely vary, and latest climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) still show significant differences in their simulated energy budgets on a land mean basis, which prevents a consistent simulation of the land surface processes in these models. In the present study we use to the extent possible direct observations of surface radiative fluxes from the Global Energy Balance Archive (GEBA) and the Baseline Surface Radiation Network (BSRN) to better constrain the simulated fluxes over global land surfaces. These model-calculated fluxes stem from the comprehensive set of more than 40 global climate from CMIP5 used in the latest IPCC report AR5. The CMIP5 models overall still show a tendency to overestimate the downward solar and underestimate the downward thermal radiation at terrestrial surfaces, a long standing problem in climate modelling. Based on the direct radiation observations and the bias structure of the CMIP5 models we infer best estimates for the downward solar and thermal radiation averaged over global land surfaces. They amount to 184 Wm-2 and 306 Wm-2, respectively. These values closely agree with the respective quantities independently derived by recent state-of-the-art reanalyses

  12. Atmosphere-only GCM (ACCESS1.0) simulations with prescribed land surface temperatures

    NASA Astrophysics Data System (ADS)

    Ackerley, Duncan; Dommenget, Dietmar

    2016-06-01

    General circulation models (GCMs) are valuable tools for understanding how the global ocean-atmosphere-land surface system interacts and are routinely evaluated relative to observational data sets. Conversely, observational data sets can also be used to constrain GCMs in order to identify systematic errors in their simulated climates. One such example is to prescribe sea surface temperatures (SSTs) such that 70 % of the Earth's surface temperature field is observationally constrained (known as an Atmospheric Model Intercomparison Project, AMIP, simulation). Nevertheless, in such simulations, land surface temperatures are typically allowed to vary freely, and therefore any errors that develop over the land may affect the global circulation. In this study therefore, a method for prescribing the land surface temperatures within a GCM (the Australian Community Climate and Earth System Simulator, ACCESS) is presented. Simulations with this prescribed land surface temperature model produce a mean climate state that is comparable to a simulation with freely varying land temperatures; for example, the diurnal cycle of tropical convection is maintained. The model is then developed further to incorporate a selection of "proof of concept" sensitivity experiments where the land surface temperatures are changed globally and regionally. The resulting changes to the global circulation in these sensitivity experiments are found to be consistent with other idealized model experiments described in the wider scientific literature. Finally, a list of other potential applications is described at the end of the study to highlight the usefulness of such a model to the scientific community.

  13. A Study on the Influence of the Land Surface Processes on the Southwest Monsoon Simulations using a Regional Climate Model

    NASA Astrophysics Data System (ADS)

    Srinivas, C. V.; Bhaskar Rao, D. V.; Hari Prasad, D.; Hari Prasad, K. B. R. R.; Baskaran, R.; Venkatraman, B.

    2015-10-01

    Influence of the land surface processes as an important mechanism in the development of the Indian Summer Monsoon is studied by performing simulations with a regional atmospheric model. Seasonal scale simulations are conducted for two contrasting summer monsoons (MJJAS months) in 2008 & 2009 with the Weather Research and Forecasting-Advanced Research regional model at a high resolution of 15 km using the boundary conditions derived from the National Centers for Environmental Prediction (NCEP) reanalysis data and using the NOAH land surface parameterization scheme. Simulations are evaluated by comparison of precipitation with 0.5° India Meteorological Department gridded rainfall data over land, atmospheric circulation fields with 1° resolution NCEP global final analysis, and surface fluxes with 0.75° resolution Era-Interim reanalysis. Results indicated significant variation in the evolution of the surface fluxes, air temperatures and flux convergence in the 2 contrasting years. A lower albedo, higher heating (sensible, latent heat fluxes), higher air temperatures, stronger flow and higher moisture flux convergence are noted over the subcontinent during the monsoon 2008 relative to the monsoon 2009. The simulated surface fluxes are in good comparison with observations. The stronger flow in 2008 is found to be associated with stronger heat flux gradients as well as stronger north-south geopotential/pressure gradients. The simulations revealed notable differences in many features such as zonal and meridional surface sensible heat gradients which, in turn, influenced the low-level pressure gradients, wind flow, and moisture transport. The present study reveals that, even at a regional scale, the physical processes of land-surface energy partitioning do influence the regional behavior of the monsoon system to a certain extent.

  14. Inferring land surface parameters from the diurnal variability of microwave and infrared temperatures

    NASA Astrophysics Data System (ADS)

    Norouzi, Hamidreza; Temimi, Marouane; AghaKouchak, Amir; Azarderakhsh, Marzieh; Khanbilvardi, Reza; Shields, Gerarda; Tesfagiorgis, Kibrewossen

    This study investigates the properties of the diurnal cycle of microwave brightness temperatures (TB), namely the phase and the amplitude, and their variability in time and space over the globe to infer information on key land surface parameters like changes in soil texture spatial distribution, soil moisture conditions, and vegetation density. The phase corresponds to the lag between Land Surface Temperature (LST) and TB diurnal cycles. The amplitude is determined as the difference between the maximum and the minimum of TB diurnal cycle. The diurnal cycle of TB was constructed using observations from the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and the Special Sensor Microwave/Imager (SSM/I). The latter offer a series of sensors, namely, F13, F14, and F15 that were used in this study for a higher temporal coverage and more accurate diurnal cycle determination. LST estimates, which are available every 3 h from the International Satellite Cloud Climatology Project (ISCCP) database were used to build the LST diurnal cycle. ISCCP LST data is an infrared-based temperature with almost no penetration and is the representative of top skin temperature. The analyses of the diurnal cycles showed that the diurnal amplitude of TB decreases as the vegetation density increases, especially in the case of low frequencies which penetrate deeper into the canopy which makes them more sensitive to changes in vegetation density. The interannual variations of TB diurnal amplitudes were also in agreement with the seasonality of the vegetation cover. Over desert and rain forest regions where surface conditions do not vary significantly throughout the year, the changes in diurnal amplitudes were the lowest. A relationship between phase and amplitude values was established. It was found that the amplitude of TB diurnal cycle decreases when the phase lag increases. The spatial distribution of the determined diurnal properties, namely, phase and amplitude of TB

  15. Can interannual land surface signal be discerned in composite AVHRR data?

    NASA Astrophysics Data System (ADS)

    Cihlar, J.; Chen, J. M.; Li, Z.; Huang, F.; Latifovic, R.; Dixon, R.

    1998-09-01

    The ability to make repeated measurements of the changing Earth's surface is the principal advantage of satellite remote sensing. To realize its potential, it is necessary that true surface changes be isolated in the satellite signal from other effects which also influence the signal. In this study, we explore the magnitude of such effects in composite NOAA advanced very high resolution radiometer (AVHRR) images with a pixel spacing of 1 km. A compositing procedure is frequently used in the preparation of data sets for land biosphere studies to minimize the effect of clouds. However, the composite images contain residual artifacts which make it difficult to compare measurements at various times. We have employed a 4-year (1993-1996) AVHRR data set from NOAA 11 and 14 covering the Canadian landmass and corrected these data for the influence of the remaining clouds (full pixel or subpixel), atmospheric attenuation, and bidirectional reflectance. We have found that such corrections are essential for studies of interannual variations. The magnitude of the interannual signal varied with the AVHRR channel, land cover type, and satellite sensor but it was reduced by a factor of 2 to 8 between top of the atmosphere and the normalized surface reflectance. The remaining variations consisted of true interannual signal and the residual noise in the data (including sensor calibration) which was not removed by the correction process. Assuming that barren or sparsely vegetated land in northern Canada has not changed over the 4-year period, the mean residual uncertainty in surface reflectance of the selected sites was 0.012 for AVHRR channel 1, 0.042 for channel 2, and 0.068 for the normalized difference vegetation index (NDVI). These values decreased to 0.011, 0.024 and 0.038, respectively, when excluding 1994 data because their atmospheric and bidirectional corrections were hampered by high solar zenith angles (mean values above 55° in all 1994 composite periods). The errors

  16. Identifying surface response to drought and heat with a land surface model and NDVI

    NASA Astrophysics Data System (ADS)

    Harrison, L. S.; Michaelsen, J.; Funk, C. C.; Carvalho, L. V.; Still, C. J.; McNally, A.; Peters-Lidard, C. D.

    2012-12-01

    Lack of in situ observations makes drought monitoring a challenge in East Africa. Hence an effective means of identifying climate hazards and surface impacts are satellite-based rainfall estimates and vegetation observations. During the 2011 Kenyan drought Rainfall Estimation Algorithm Version 2 (RFE2.0) and expedited Moderate Resolution Imaging Spectroradiometer (eMODIS) NDVI products were used to delineate regional gradients of food insecurity, a critical factor in prompt distribution of aid. Land surface models (LSM) beckon as a means for expanding our understanding of drought. Modeled turbulent surface fluxes may make explicit physical processes responsible for observed plant stress. When sensible heating occurs under low evapotranspiration (AET) conditions, we would expect vegetation stress to increase. In this paper we examine two aspects of temperature-vegetation stress as interpreted by a LSM: (1) To what extent do sensible heating anomalies accompany AET anomalies and (2) how do rainfall and temperature influence energy partitioning? We investigate for the March-May rainy season (2001-12) across Kenya's rangelands at interannual and sub-seasonal timescales. Results highlight landscape characteristics with disproportionate sensitivity to climate. LSM estimates are compared to the vegetation response observed with NDVI. We establish the relationship between sources and use 2009 and 2011 agro-pastoral droughts as criteria for the LSM as a potential monitoring tool. Climate and flux data are from Noah3.2 LSM forced with RFE2.0 rainfall in a custom configuration of the NASA Land Information System. Satellite observations are from eMODIS NDVI.

  17. Internal Physical Features of a Land Surface Model Employing a Tangent Linear Model

    NASA Technical Reports Server (NTRS)

    Yang, Runhua; Cohn, Stephen E.; daSilva, Arlindo; Joiner, Joanna; Houser, Paul R.

    1997-01-01

    The Earth's land surface, including its biomass, is an integral part of the Earth's weather and climate system. Land surface heterogeneity, such as the type and amount of vegetative covering., has a profound effect on local weather variability and therefore on regional variations of the global climate. Surface conditions affect local weather and climate through a number of mechanisms. First, they determine the re-distribution of the net radiative energy received at the surface, through the atmosphere, from the sun. A certain fraction of this energy increases the surface ground temperature, another warms the near-surface atmosphere, and the rest evaporates surface water, which in turn creates clouds and causes precipitation. Second, they determine how much rainfall and snowmelt can be stored in the soil and how much instead runs off into waterways. Finally, surface conditions influence the near-surface concentration and distribution of greenhouse gases such as carbon dioxide. The processes through which these mechanisms interact with the atmosphere can be modeled mathematically, to within some degree of uncertainty, on the basis of underlying physical principles. Such a land surface model provides predictive capability for surface variables including ground temperature, surface humidity, and soil moisture and temperature. This information is important for agriculture and industry, as well as for addressing fundamental scientific questions concerning global and local climate change. In this study we apply a methodology known as tangent linear modeling to help us understand more deeply, the behavior of the Mosaic land surface model, a model that has been developed over the past several years at NASA/GSFC. This methodology allows us to examine, directly and quantitatively, the dependence of prediction errors in land surface variables upon different vegetation conditions. The work also highlights the importance of accurate soil moisture information. Although surface

  18. Land Surface Process and Air Quality Research and Applications at MSFC

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale; Khan, Maudood

    2007-01-01

    This viewgraph presentation provides an overview of land surface process and air quality research at MSFC including atmospheric modeling and ongoing research whose objective is to undertake a comprehensive spatiotemporal analysis of the effects of accurate land surface characterization on atmospheric modeling results, and public health applications. Land use maps as well as 10 meter air temperature, surface wind, PBL mean difference heights, NOx, ozone, and O3+NO2 plots as well as spatial growth model outputs are included. Emissions and general air quality modeling are also discussed.

  19. Towards a protocol for validating satellite-based Land Surface Temperature: Theoretical considerations

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; Ghent, Darren J.; Corlett, Gary C.; Prata, Fred; Remedios, John J.

    2013-04-01

    Land Surface Temperature (LST) and emissivity are important parameters for environmental monitoring and earth system modelling. LST has been observed from space for several decades using a wide variety of satellite instruments with different characteristics, including both platforms in low-earth orbit and in geostationary orbit. This includes for example the series of Advanced Very High Resolution Radiometers (AVHRR) delivering a continuous thermal infrared (TIR) data stream since the early 1980s, the series of Along-Track Scanning Radiometers (ATSR) providing TIR data since 1991, and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments onboard NASA's Terra and Aqua platforms, providing data since the year 2000. In addition, the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard of the geostationary Meteosat satellites is now providing LST at unprecedented sub-hour frequency. The data record provided by such instruments is extremely valuable for a wide variety of applications, including climate change, land/atmosphere feedbacks, fire monitoring, modelling, land cover change, geology, crop- and water management. All of these applications, however, require a rigorous validation of the data in order to assess the product quality and the associated uncertainty. Here we report on recent work towards developing a protocol for validation of satellite-based Land Surface Temperature products. Four main validation categories are distinguished within the protocol: A) Comparison with in situ observations, B) Radiance-based validation, C) Inter-comparison with similar LST products, and D) Time-series analysis. Each category is further subdivided into several quality classes, which approximately reflect the validation accuracy that can be achieved by the different approaches, as well as the complexity involved with each method. Advice on best practices is given for methodology common to all categories. For each validation category, recommendations

  20. A simple hydrologically based model of land surface water and energy fluxes for general circulation models

    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.

  1. Globalland30 Mapping Capacity of Land Surface Water in Thessaly, Greece

    NASA Astrophysics Data System (ADS)

    Manakos, Ioannis; Chatzopoulos-Vouzoglanis, Konstantinos; Petrou, Zisis I.; Filchev, Lachezar; Apostolakis, Antonis

    2015-01-01

    The National Geomatics Center of China (NGCC) produced Global Land Cover (GlobalLand30) maps with 30 m spatial resolution for the years 2000 and 2009-2010, responding to the need for harmonized, accurate, and high-resolution global land cover data. This study aims to assess the mapping accuracy of the land surface water layer of GlobalLand30 for 2009-2010. A representative Mediterranean region, situated in Greece, is considered as the case study area, with 2009 as the reference year. The assessment is realized through an object-based comparison of the GlobalLand30 water layer with the ground truth and visually interpreted data from the Hellenic Cadastre fine spatial resolution (0.5 m) orthophoto map layer. GlobCover 2009, GlobCorine 2009, and GLCNMO 2008 corresponding thematic layers are utilized to show and quantify the progress brought along with the increment of the spatial resolution, from 500 m to 300 m and finally to 30 m with the newly produced GlobalLand30 maps. GlobalLand30 detected land surface water areas show a 91.9% overlap with the reference data, while the coarser resolution products are restricted to lower accuracies. Validation is extended to the drainage network elements, i.e., rivers and streams, where GlobalLand30 outperforms the other global map products, as well.

  2. A joint NOAA/USGS study to evaluate satellite assessment of land surface features and climatic variables

    USGS Publications Warehouse

    Gallo, K.P.; Tarpley, J.D.; Howard, S.M.; Moore, D.G.

    1987-01-01

    Data collection and preliminary analyses have begun for a study that will evaluate the usefulness of satellite data for assessment of land surface features and climatic variables. The objective of the study is to determine what relationships exist between routinely available ground-based climatic and land surface information and satellite-obtained land surface information. The overall goal is to contribute to the increasingly important understanding of land surface climatology.

  3. The impact of implementing the bare essentials of surface transfer land surface scheme into the BMRC GCM

    SciTech Connect

    Yang, Z.L.; Pitman, A.J.; McAvaney, B.

    1995-07-01

    This study describes the first order impacts of incorporating a complex land-surface scheme, the bare essentials of surface transfer (BEST), into the Australian Bureau of Meteorology Research Centre (BMRC) global atmospheric general circulation model (GCM). Land seasonal climatologies averaged over the last six years of integrations after equilibrium from the GCM with BEST and without BEST (the control) are compared. The modeled results are evaluated with comprehensive sources of data, including the layer-cloud climatologies project (ISCCP) data from 1983 to 1991 and the surface-observed global data of Warrent et al., a five-year climatology of surface albedo estimated from earth radiation budget experiment (ERBE) top-of-the-atmosphere (TOA) radiative fluxes, global grid point datasets of precipitation, and the climatological analyses of surface evaporation and albedo. Emphasis is placed on the surface evaluation of simulations of land-surface conditions such as surface roughness, surface albedo and the surface wetness factor, and on their effects on surface evaporation, precipitation, layer-cloud and surface temperature. The improvements due to the inclusion of BEST are: a realistic geographical distribution of surface roughness, a decrease in surface albedo over areas with seasonal snow cover, an an increase in surface albedo over snow-free land. The simulated reduction in surface evaporation due, in part, to the bio-physical control of vegetation, is also consistent with the previous studies. Since the control climate has a dry bias, the overall simulations from the GCM with BEST are degraded, except for significant improvements for the northern winter hemisphere because of the realistic vegetation-masking effects. The implications of our results for synergistic developments of other aspects of model parameterization schemes such as boundary layer dynamics, clouds, convection and rainfall are discussed. 82 refs., 9 figs., 3 tabs.

  4. Water Balance in the Amazon Basin from a Land Surface Model Ensemble

    NASA Technical Reports Server (NTRS)

    Getirana, Augusto C. V.; Dutra, Emanuel; Guimberteau, Matthieu; Kam, Jonghun; Li, Hong-Yi; Decharme, Bertrand; Zhang, Zhengqiu; Ducharne, Agnes; Boone, Aaron; Balsamo, Gianpaolo; Rodell, Matthew; Toure, Ally M.; Xue, Yongkang; Peters-Lidard, Christa D.; Kumar, Sujay V.; Arsenault, Kristi; Drapeau, Guillaume; Leung, L. Ruby; Ronchail, Josyane; Sheffield, Justin

    2014-01-01

    Despite recent advances in land surfacemodeling and remote sensing, estimates of the global water budget are still fairly uncertain. This study aims to evaluate the water budget of the Amazon basin based on several state-ofthe- art land surface model (LSM) outputs. Water budget variables (terrestrial water storage TWS, evapotranspiration ET, surface runoff R, and base flow B) are evaluated at the basin scale using both remote sensing and in situ data. Meteorological forcings at a 3-hourly time step and 18 spatial resolution were used to run 14 LSMs. Precipitation datasets that have been rescaled to matchmonthly Global Precipitation Climatology Project (GPCP) andGlobal Precipitation Climatology Centre (GPCC) datasets and the daily Hydrologie du Bassin de l'Amazone (HYBAM) dataset were used to perform three experiments. The Hydrological Modeling and Analysis Platform (HyMAP) river routing scheme was forced with R and B and simulated discharges are compared against observations at 165 gauges. Simulated ET and TWS are compared against FLUXNET and MOD16A2 evapotranspiration datasets andGravity Recovery and ClimateExperiment (GRACE)TWSestimates in two subcatchments of main tributaries (Madeira and Negro Rivers).At the basin scale, simulated ET ranges from 2.39 to 3.26 mm day(exp -1) and a low spatial correlation between ET and precipitation indicates that evapotranspiration does not depend on water availability over most of the basin. Results also show that other simulated water budget components vary significantly as a function of both the LSM and precipitation dataset, but simulated TWS generally agrees with GRACE estimates at the basin scale. The best water budget simulations resulted from experiments using HYBAM, mostly explained by a denser rainfall gauge network and the rescaling at a finer temporal scale.

  5. Hyperresolution Global Land Surface Modeling: Meeting a Grand Challenge for Monitoring Earth's Terrestrial Water

    NASA Technical Reports Server (NTRS)

    Wood, Eric F.; Roundy, Joshua K.; Troy, Tara J.; van Beek, L. P. H.; Bierkens, Marc F. P.; 4 Blyth, Eleanor; de Roo, Ad; Doell. Petra; Ek, Mike; Famiglietti, James; Gochis, David; van de Giesen, Nick; Houser, Paul; Jaffe, Peter R.; Kollet, Stefan; Lehner, Bernhard; Lettenmaier, Dennis P.; Peters-Lidard, Christa; Sivpalan, Murugesu; Sheffield, Justin; Wade, Andrew; Whitehead, Paul

    2011-01-01

    Monitoring Earth's terrestrial water conditions is critically important to many hydrological applications such as global food production; assessing water resources sustainability; and flood, drought, and climate change prediction. These needs have motivated the development of pilot monitoring and prediction systems for terrestrial hydrologic and vegetative states, but to date only at the rather coarse spatial resolutions (approx.10-100 km) over continental to global domains. Adequately addressing critical water cycle science questions and applications requires systems that are implemented globally at much higher resolutions, on the order of 1 km, resolutions referred to as hyperresolution in the context of global land surface models. This opinion paper sets forth the needs and benefits for a system that would monitor and predict the Earth's terrestrial water, energy, and biogeochemical cycles. We discuss six major challenges in developing a system: improved representation of surface-subsurface interactions due to fine-scale topography and vegetation; improved representation of land-atmospheric interactions and resulting spatial information on soil moisture and evapotranspiration; inclusion of water quality as part of the biogeochemical cycle; representation of human impacts from water management; utilizing massively parallel computer systems and recent computational advances in solving hyperresolution models that will have up to 10(exp 9) unknowns; and developing the required in situ and remote sensing global data sets. We deem the development of a global hyperresolution model for monitoring the terrestrial water, energy, and biogeochemical cycles a grand challenge to the community, and we call upon the international hydrologic community and the hydrological science support infrastructure to endorse the effort.

  6. High resolution land surface response of inland moving Indian monsoon depressions over Bay of Bengal

    NASA Astrophysics Data System (ADS)

    Rajesh, P. V.; Pattnaik, S.

    2016-05-01

    During Indian summer monsoon (ISM) season, nearly about half of the monsoonal rainfall is brought inland by the low pressure systems called as Monsoon Depressions (MDs). These systems bear large amount of rainfall and frequently give copious amount of rainfall over land regions, therefore accurate forecast of these synoptic scale systems at short time scale can help in disaster management, flood relief, food safety. The goal of this study is to investigate, whether an accurate moisture-rainfall feedback from land surface can improve the prediction of inland moving MDs. High Resolution Land Data Assimilation System (HRLDAS) is used to generate improved land state .i.e. soil moisture and soil temperature profiles by means of NOAH-MP land-surface model. Validation of the model simulated basic atmospheric parameters at surface layer and troposphere reveals that the incursion of high resolution land state yields least Root Mean Squared Error (RMSE) with a higher correlation coefficient and facilitates accurate depiction of MDs. Rainfall verification shows that HRLDAS simulations are spatially and quantitatively in more agreement with the observations and the improved surface characteristics could result in the realistic reproduction of the storm spatial structure, movement as well as intensity. These results signify the necessity of investigating more into the land surface-rainfall feedbacks through modifications in moisture flux convergence within the storm.

  7. Validation of spatiotemporally dense springtime land surface phenology with intensive and upscale in situ

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface phenology (LSP) developed using temporally and spatially optimized remote sensing data, is particularly promising for use in detailed ecosystem monitoring and modeling efforts. Validating spatiotemporally dense LSP using compatible (intensively collected) in situ phenological data is t...

  8. [A review on research of land surface water and heat fluxes].

    PubMed

    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.

  9. Nature's neutron probe: Land surface hydrology at an elusive scale with cosmic rays

    NASA Astrophysics Data System (ADS)

    Desilets, Darin; Zreda, Marek; Ferré, Ty P. A.

    2010-11-01

    Fast neutrons are generated naturally at the land surface by energetic cosmic rays. These "background" neutrons respond strongly to the presence of water at or near the land surface and represent a hitherto elusive intermediate spatial scale of observation that is ideal for land surface studies and modeling. Soil moisture, snow, and biomass each have a distinct influence on the spectrum, height profile, and directional intensity of neutron fluxes above the ground, suggesting that different sources of water at the land surface can be distinguished with neutron data alone. Measurements can be taken at fixed sites for long-term monitoring or in a moving vehicle for mapping over large areas. We anticipate applications in many previously problematic contexts, including saline environments, wetlands and peat bogs, rocky soils, the active layer of permafrost, and water and snow intercepted by vegetation, as well as calibration and validation of data from spaceborne sensors.

  10. Techniques Deriving Land Cover and Earth Surface Deformation Information from Polarimetric SAR Interferometry- Final Report

    NASA Astrophysics Data System (ADS)

    Pottier, E.; Chen, E.; Li, Z.; Hong, W.; Xiang, M.; Li, Y.; Cloude, S. R.; Papathanassiou, K.; Zhang, L.; Li, X.

    2013-01-01

    In this paper we provide a summary of activities carried out under the DRAGON collaborative program in a project concerned with the application of Pol-InSAR to deriving land cover and Earth Surface deformation information. This project (ID. 5344) is based around four main scientific topics: Land Cover Analysis, Earth Surface Deformation Monitoring and DEM Extraction, Forest Vertical Structure Parameters Extraction and PolSARpro Software Development.

  11. Modeling the influence of land surface flux on the regional climate of the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ma, Weiqiang; Ma, Yaoming

    2016-07-01

    Land surface heat fluxes over the heterogeneous landscape of the Tibetan Plateau can serve as boundary conditions for modeling the regional climate and the Asian monsoon system. The Weather Research and Forecasting (WRF) atmospheric modeling system has enabled us to model the land surface heat flux through sensitivity experiments that utilize in situ observation data and the regional land-atmosphere exchanges of water and heat fluxes that are foundational to understanding the water and energy cycles present during the Asian monsoon period. A series of sensitivity experiments based on the WRF model and field observations has been proposed and tested for deriving the land surface heat fluxes (surface net radiation flux, soil heat flux, sensible heat flux, and latent heat flux) over a heterogeneous land surface. The sensitivity experiments were simulated over the field area of the Coordinated Enhanced Observing Period Asia-Australia Monsoon Project on the Tibetan Plateau (CEOP-CAMP/Tibet), located on the northern Tibetan Plateau of China. A WRF modeling period from July to August 2007 was selected for the summer monsoon conditions. To validate the modeling results, the ground-measured or calculated variables (e.g., net radiation flux, soil heat flux, sensible heat flux, and latent heat flux) were compared to the simulated values. The modeling results show that the derived model land surface heat fluxes are in agreement with the land surface observations over the study area in summer. Therefore, the WRF model sensitivity experiments were successful in simulating the land surface heat fluxes over the study area.

  12. Land surface temperature inversion of bare soil and vegetation cover based on MODIS data

    NASA Astrophysics Data System (ADS)

    Li, Jingwen; Zhou, Song; Wang, Zhezhen; Lv, Nan; Jiang, Jianwu; Wang, Ke

    2015-12-01

    Land surface temperature is one of the most important parameters in hydrology and agricultural production research . Split-window algorithm based on MODIS data was briefly introduced in this paper and applied in Hetao Irrigation District. Comparison between data retrieval and field collected data showed that data retrieval could reflect land surface temperature basic accurately .Linear fitting of different time series data can improve retrieval precision effectively. The results provide support for drought forecast, soil moisture monitoring etc. in the future.

  13. 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.

  14. Coal surface control for advanced physical fine coal cleaning technologies

    SciTech Connect

    Morsi, B.I.; Chiang, S.H.; Sharkey, A.; Blachere, J.; Klinzing, G.; Araujo, G.; Cheng, Y.S.; Gray, R.; Streeter, R.; Bi, H.; Campbell, P.; Chiarlli, P.; Ciocco, M.; Hittle, L.; Kim, S.; Kim, Y.; Perez, L.; Venkatadri, R.

    1992-01-01

    This final report presents the research work carried out on the Coal Surface Control for Advanced Physical Fine Coal Cleaning Technologies project, sponsored by the US Department of Energy, Pittsburgh Energy Technology Center (DOE/PETC). The project was to support the engineering development of the selective agglomeration technology in order to reduce the sulfur content of US coals for controlling SO[sub 2] emissions (i.e., acid rain precursors). The overall effort was a part of the DOE/PETCs Acid Rain Control Initiative (ARCI). The overall objective of the project is to develop techniques for coal surface control prior to the advanced physical fine coal cleaning process of selective agglomeration in order to achieve 85% pyrite sulfur rejection at an energy recovery greater than 85% based on run-of-mine coal. The surface control is meant to encompass surface modification during grinding and laboratory beneficiation testing. The project includes the following tasks: Project planning; methods for analysis of samples; development of standard beneficiation test; grinding studies; modification of particle surface; and exploratory R D and support. The coal samples used in this project include three base coals, Upper Freeport - Indiana County, PA, Pittsburgh NO. 8 - Belmont County, OH, and Illinois No. 6 - Randolph County, IL, and three additional coals, Upper Freeport - Grant County- WV, Kentucky No. 9 Hopkins County, KY, and Wyodak - Campbell County, WY. A total of 149 drums of coal were received.

  15. Modelling the Relationship Between Land Surface Temperature and Landscape Patterns of Land Use Land Cover Classification Using Multi Linear Regression Models

    NASA Astrophysics Data System (ADS)

    Bernales, A. M.; Antolihao, J. A.; Samonte, C.; Campomanes, F.; Rojas, R. J.; dela Serna, A. M.; Silapan, J.

    2016-06-01

    The threat of the ailments related to urbanization like heat stress is very prevalent. There are a lot of things that can be done to lessen the effect of urbanization to the surface temperature of the area like using green roofs or planting trees in the area. So land use really matters in both increasing and decreasing surface temperature. It is known that there is a relationship between land use land cover (LULC) and land surface temperature (LST). Quantifying this relationship in terms of a mathematical model is very important so as to provide a way to predict LST based on the LULC alone. This study aims to examine the relationship between LST and LULC as well as to create a model that can predict LST using class-level spatial metrics from LULC. LST was derived from a Landsat 8 image and LULC classification was derived from LiDAR and Orthophoto datasets. Class-level spatial metrics were created in FRAGSTATS with the LULC and LST as inputs and these metrics were analysed using a statistical framework. Multi linear regression was done to create models that would predict LST for each class and it was found that the spatial metric "Effective mesh size" was a top predictor for LST in 6 out of 7 classes. The model created can still be refined by adding a temporal aspect by analysing the LST of another farming period (for rural areas) and looking for common predictors between LSTs of these two different farming periods.

  16. Impact of land surface conditions on 2004 North American monsoon in GCM experiments

    NASA Astrophysics Data System (ADS)

    Feng, X.; Bosilovich, M.; Houser, P.; Chern, J.-D.

    2013-01-01

    In this study, two sets of six-member ensemble simulations were performed for the boreal summer of 2004 using the Finite Volume General Circulation model to investigate the sensitivity of the North American monsoon (NAM) system to land surface conditions and further to identify the mechanisms by which land surface processes control the NAM precipitation. The control simulation uses a fully interactive land surface model, whereas the sensitivity experiment uses prescribed land surface fields from the Global Land Data Assimilation System.The response of the monsoon precipitation to land surface changes varies over different regions modulated by two different soil moisture-precipitation feedbacks. The vast northern NAM region, including most of Arizona and New Mexico, as well as the northwestern Mexico shows that soil moisture has a positive feedback with precipitation primarily due to local recycling mechanisms. The reduction of soil moisture decreases latent heat flux and increases sensible heat flux and consequently increases the Bowen ratio and surface temperature, leading to a deep (warm and dry) boundary layer, which suppresses convection and hence reduces precipitation. Over the west coast of Mexico near Sinaloa, a negative soil moisture-precipitation relationship is noted to be associated with a large-scale mechanism. The reduced soil moisture changes surface fluxes and hence boundary layer instability and ultimately low-level circulation. As a result, the changes in surface pressure and large scale wind field increase moisture flux convergence and consequently moisture content, leading to increased atmospheric instability and in turn enhancing convection and accordingly precipitation. These results further reinforce the important role of land surface conditions on surface process, boundary structure, atmospheric circulation, and rainfall during the NAM development.

  17. Discrepancy Between ASTER- and MODIS- Derived Land Surface Temperatures: Terrain Effects.

    PubMed

    Liu, Yuanbo; Noumi, Yousuke; Yamaguchi, Yasushi

    2009-01-01

    The MODerate resolution Imaging Spectroradiometer (MODIS) and the Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) are onboard the same satellite platform NASA TERRA. Both MODIS and ASTER offer routine retrieval of land surface temperatures (LSTs), and the ASTER- and MODIS-retrieved LST products have been used worldwide. Because a large fraction of the earth surface consists of mountainous areas, variations in elevation, terrain slope and aspect angles can cause biases in the retrieved LSTs. However, terrain-induced effects are generally neglected in most satellite retrievals, which may generate discrepancy between ASTER and MODIS LSTs. In this paper, we reported the terrain effects on the LST discrepancy with a case examination over a relief area at the Loess Plateau of China. Results showed that the terrain-induced effects were not major, but nevertheless important for the total LST discrepancy. A large local slope did not necessarily lead to a large LST discrepancy. The angle of emitted radiance was more important than the angle of local slope in generating the LST discrepancy. Specifically, the conventional terrain correction may be unsuitable for densely vegetated areas. The distribution of ASTER-to-MODIS emissivity suggested that the terrain correction was included in the generalized split window (GSW) based approach used to rectify MODIS LSTs. Further study should include the classification-induced uncertainty in emissivity for reliable use of satellite-retrieved LSTs over relief areas.

  18. A Practical Method for Retrieving Land Surface Temperature from AMSR-E over the Amazon Forest

    NASA Astrophysics Data System (ADS)

    Gao, H.; Fu, R.; Dickinson, R.; Negrón Juárez, R. I.

    2007-12-01

    Remote sensing of land surface temperature (LST) using infrared sensors, such as the Moderate Resolution Imaging Spectroradiometer (MODIS), is only capable of retrieval under clear-sky conditions. Such LST observations over tropical forests are very limited due to clouds and rainfall, especially during the wet season, and high atmospheric water vapor content. In comparison, low frequency microwave radiances are minimally influenced by meteorological conditions. Exploring this advantage, we have developed an algorithm to retrieve LST over the Amazonian forest. The algorithm uses multi-frequency polarized microwave brightness temperatures from the Advanced Microwave Scanning Radiometer (AMSR-E) on NASA's Earth Observing System. Relationships between polarization ratio and surface emissivity are established for forested and non-forested areas, such that LST can be calculated solely from microwave radiance. Results are presented over three time scales: at each orbit, daily, and monthly. Results are evaluated by comparing with available air temperature records on daily and monthly intervals. Our findings indicate that the AMSR-E derived LST agrees well with in situ measurements. Results during the wet season over the tropical forest suggest that AMSR-E LST is robust under all-weather conditions and shows higher correlation to meteorological data (r=0.70) than infrared based LST approaches (r=0.42).

  19. Discrepancy Between ASTER- and MODIS- Derived Land Surface Temperatures: Terrain Effects.

    PubMed

    Liu, Yuanbo; Noumi, Yousuke; Yamaguchi, Yasushi

    2009-01-01

    The MODerate resolution Imaging Spectroradiometer (MODIS) and the Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) are onboard the same satellite platform NASA TERRA. Both MODIS and ASTER offer routine retrieval of land surface temperatures (LSTs), and the ASTER- and MODIS-retrieved LST products have been used worldwide. Because a large fraction of the earth surface consists of mountainous areas, variations in elevation, terrain slope and aspect angles can cause biases in the retrieved LSTs. However, terrain-induced effects are generally neglected in most satellite retrievals, which may generate discrepancy between ASTER and MODIS LSTs. In this paper, we reported the terrain effects on the LST discrepancy with a case examination over a relief area at the Loess Plateau of China. Results showed that the terrain-induced effects were not major, but nevertheless important for the total LST discrepancy. A large local slope did not necessarily lead to a large LST discrepancy. The angle of emitted radiance was more important than the angle of local slope in generating the LST discrepancy. Specifically, the conventional terrain correction may be unsuitable for densely vegetated areas. The distribution of ASTER-to-MODIS emissivity suggested that the terrain correction was included in the generalized split window (GSW) based approach used to rectify MODIS LSTs. Further study should include the classification-induced uncertainty in emissivity for reliable use of satellite-retrieved LSTs over relief areas. PMID:22399955

  20. Long-range cross-correlation between urban impervious surfaces and land surface temperatures

    NASA Astrophysics Data System (ADS)

    Nie, Qin; Xu, Jianhua; Man, Wang

    2016-03-01

    The thermal effect of urban impervious surfaces (UIS) is a complex problem. It is thus necessary to study the relationship between UIS and land surface temperatures (LST) using complexity science theory and methods. This paper investigates the long-range cross-correlation between UIS and LST with detrended cross-correlation analysis and multifractal detrended cross-correlation analysis, utilizing data from downtown Shanghai, China. UIS estimates were obtained from linear spectral mixture analysis, and LST was retrieved through application of the mono-window algorithm, using Landsat Thematic Mapper and Enhanced Thematic Mapper Plus data for 1997-2010. These results highlight a positive long-range cross-correlation between UIS and LST across People's Square in Shanghai. LST has a long memory for a certain spatial range of UIS values, such that a large increment in UIS is likely to be followed by a large increment in LST. While the multifractal long-range cross-correlation between UIS and LST was observed over a longer time period in the W-E direction (2002-2010) than in the N-S (2007-2010), these observed correlations show a weakening during the study period as urbanization increased.

  1. Identifying the Local Surface Urban Heat Island Through the Morphology of the Land Surface Temperature

    NASA Astrophysics Data System (ADS)

    Wang, Jiong; Zhan, Qingming; Xiao, Yinghui

    2016-06-01

    Current characterization of the Land Surface Temperature (LST) at city scale insufficiently supports efficient mitigations and adaptations of the Surface Urban Heat Island (SUHI) at local scale. This research intends to delineate the LST variation at local scale where mitigations and adaptations are more feasible. At the local scale, the research helps to identify the local SUHI (LSUHI) at different levels. The concept complies with the planning and design conventions that urban problems are treated with respect to hierarchies or priorities. Technically, the MODerate-resolution Imaging Spectroradiometer satellite image products are used. The continuous and smooth latent LST is first recovered from the raw images. The Multi-Scale Shape Index (MSSI) is then applied to the latent LST to extract morphological indicators. The local scale variation of the LST is quantified by the indicators such that the LSUHI can be identified morphologically. The results are promising. It can potentially be extended to investigate the temporal dynamics of the LST and LSUHI. This research serves to the application of remote sensing, pattern analysis, urban microclimate study, and urban planning at least at 2 levels: (1) it extends the understanding of the SUHI to the local scale, and (2) the characterization at local scale facilitates problem identification and support mitigations and adaptations more efficiently.

  2. The impact of climatic and non-climatic factors on land surface temperature in southwestern Romania

    NASA Astrophysics Data System (ADS)

    Roşca, Cristina Florina; Harpa, Gabriela Victoria; Croitoru, Adina-Eliza; Herbel, Ioana; Imbroane, Alexandru Mircea; Burada, Doina Cristina

    2016-09-01

    Land surface temperature is one of the most important parameters related to global warming. It depends mainly on soil type, discontinuous vegetation cover, or lack of precipitation. The main purpose of this paper is to investigate the relationship between high LST, synoptic conditions and air masses trajectories, vegetation cover, and soil type in one of the driest region in Romania. In order to calculate the land surface temperature and normalized difference vegetation index, five satellite images of LANDSAT missions 5 and 7, covering a period of 26 years (1986-2011), were selected, all of them collected in the month of June. The areas with low vegetation density were derived from normalized difference vegetation index, while soil types have been extracted from Corine Land Cover database. HYSPLIT application was employed to identify the air masses origin based on their backward trajectories for each of the five study cases. Pearson, logarithmic, and quadratic correlations were used to detect the relationships between land surface temperature and observed ground temperatures, as well as between land surface temperature and normalized difference vegetation index. The most important findings are: strong correlation between land surface temperature derived from satellite images and maximum ground temperature recorded in a weather station located in the area, as well as between areas with land surface temperature equal to or higher than 40.0 °C and those with lack of vegetation; the sandy soils are the most prone to high land surface temperature and lack of vegetation, followed by the chernozems and brown soils; extremely severe drought events may occur in the region.

  3. Improving evapotranspiration in a land surface model using biophysical variables derived from MSG/SEVIRI satellite

    NASA Astrophysics Data System (ADS)

    Ghilain, N.; Arboleda, A.; Sepulcre-Cantò, G.; Batelaan, O.; Ardö, J.; Gellens-Meulenberghs, F.

    2012-08-01

    Monitoring evapotranspiration over land is highly dependent on the surface state and vegetation dynamics. Data from spaceborn platforms are desirable to complement estimations from land surface models. The success of daily evapotranspiration monitoring at continental scale relies on the availability, quality and continuity of such data. The biophysical variables derived from SEVIRI on board the geostationary satellite Meteosat Second Generation (MSG) and distributed by the Satellite Application Facility on Land surface Analysis (LSA-SAF) are particularly interesting for such applications, as they aimed at providing continuous and consistent daily time series in near-real time over Africa, Europe and South America. In this paper, we compare them to monthly vegetation parameters from a database commonly used in numerical weather predictions (ECOCLIMAP-I), showing the benefits of the new daily products in detecting the spatial and temporal (seasonal and inter-annual) variability of the vegetation, especially relevant over Africa. We propose a method to handle Leaf Area Index (LAI) and Fractional Vegetation Cover (FVC) products for evapotranspiration monitoring with a land surface model at 3-5 km spatial resolution. The method is conceived to be applicable for near-real time processes at continental scale and relies on the use of a land cover map. We assess the impact of using LSA-SAF biophysical variables compared to ECOCLIMAP-I on evapotranspiration estimated by the land surface model H-TESSEL. Comparison with in-situ observations in Europe and Africa shows an improved estimation of the evapotranspiration, especially in semi-arid climates. Finally, the impact on the land surface modelled evapotranspiration is compared over a north-south transect with a large gradient of vegetation and climate in Western Africa using LSA-SAF radiation forcing derived from remote sensing. Differences are highlighted. An evaluation against remote sensing derived land surface temperature

  4. A Technique for Assimilating GOES-Derived Land Surface Products into Regional Models to Improve the Representation of Land Surface Forcing

    NASA Technical Reports Server (NTRS)

    Lapenta, William M.; Suggs, Ron; McNider, Richard T.; Jedlovec, Gary

    1998-01-01

    As the parameterizations of surface energy budgets in regional models have become more complete physically, models have the potential to be much more realistic in simulations of coupling between surface radiation, hydrology, and surface energy transfer. Realizing the importance of properly specifying the surface energy budget, many institutions are using land-surface models to represent the lower boundary forcing associated with biophysical processes and soil hydrology. However, the added degrees of freedom due to inclusion of such land-surface schemes require the specification of additional parameters within the model system such as vegetative resistances, green vegetation fraction, leaf area index, soil physical and hydraulic characteristics, stream flow, runoff, and the vertical distribution of soil moisture. A technique has been developed for assimilating GOES-IR skin temperature tendencies into the surface energy budget equation of a mesoscale model so that the simulated rate of temperature change closely agrees with the satellite observations. A critical assumption of the technique is that the availability of moisture (either from the soil or vegetation) is the least known term in the model's surface energy budget. Therefore, the simulated latent heat flux, which is a function of surface moisture availability, is adjusted based upon differences between the modeled and satellite-observed skin temperature tendencies. An advantage of this technique is that satellite temperature tendencies are assimilated in an energetically consistent manner that avoids energy imbalances and surface stability problems that arise from direct assimilation of surface shelter temperatures. The fact that the rate of change of the satellite skin temperature is used rather than the absolute temperature means that sensor calibration is not as critical. An advantage of this technique for short-range forecasts is that it does not require a complex land-surface formulation within the

  5. Earth Observing-1 Advanced Land Imager: Dark Current and Noise Characterization and Anomalous Detectors

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.

    2001-01-01

    The dark current and noise characteristics of the Earth Observing-1 Advanced Land Imager measured during ground calibration at MIT Lincoln Laboratory are presented. Data were collected for the nominal focal plane operating temperature of 220 K as well as supplemental operating temperatures (215 and 225 K). Dark current baseline values are provided, and noise characterization includes the evaluation of white, coherent, low frequency, and high frequency components. Finally, anomalous detectors, characterized by unusual dark current, noise, gain, or cross-talk properties are investigated.

  6. Restoration of surface-mined lands with rainfall harvesting

    SciTech Connect

    Sauer, R.H.; Rickard, W.H.

    1982-12-01

    Strip mining for coal in the arid western US will remove grazing land as energy demands are met. Conventional resotration usually includes leveling the spoil banks and covering them with top soil, fertilizing, seeding and irrigation with well or river water. An overview of research on an alternate method of restoring this land is reported. From 1976 through 1981 studies were conducted on the use of water harvesting, the collection and use of rainfall runoff, to restore the vegetative productivity of strip mined lands in arid regions. These studies tested the technical and economic feasibility of using partially leveled spoil banks at strip mines as catchment areas to collect and direct runoff to the topsoiled valley floor where crops were cultivated. Information was collected on the efficiency of seven treatments to increase runoff from the catchment areas and on the productivity of seven crops. The experiments were conducted in arid areas of Washington, Arizona, and Colorado. It was concluded that water harvesting can replace or augment expensive and inadequate supplies of well and river water in arid regions with a suitable climate. These studies showed that some treatments provided adequate runoff to produce a useful crop in the valleys, thus making this alternative approach to restoration technically feasible. This approach was also potentially economically feasible where the treatment costs of the catchment areas were low, the treatment was effective, the crop was productive and valuable, and earthmoving costs were lower than with conventional restoration involving complete leveling of spoil banks. It was also concluded that water harvesting can be made more effective with further information on catchment area treatments, which crops are most adaptable to water harvesting, the optimum incline of the catchment areas and climatic influences on water harvesting.

  7. Impact of Land Surface Parameters on the Evaluation of East Asia Monsoon Precipitation

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Xue, Y.; Guo, W.

    2015-12-01

    Land surface has crucial impact on air movement through momentum, energy and mass exchange. Leaf area index (LAI), one of important variable in the land surface processes, involves in canopy radiative transfer, momentum transfer, precipitation interception loss, and transpiration, which affect on land surface energy and water partition processes. Therefore, it crucially affects the ability of models to adequately simulate land-surface interaction. In this study, Long-term Global Mapping LAI (GLOBMAP LAI) and its corresponding land cover and greenness fraction are introduced into WRF_NMM/SSiB2. Compared with the control simulation based on the original specified LAI that is based on limited survey. The simulation with GLOBMAP LAI produced better precipitation distribution and rain belt movement. The improvements of the East Asia monsoon precipitation simulation are mainly attributed to the correction of the position of subtropical high. The north edge of subtropical high is related to the position of East Asia Westerly Jet. In the control simulation, weak westerlies lead subtropical high to move northward. Therefore compared with observations, more precipitation is in high latitudes. With imposed remote sensing LAI, the model produces larger meridional temperature gradient in surface and upper air, leading to stronger thermal westerlies. The Southward of Westerly Jet blocks the subtropical high, which amends the position of monsoon rain belt. This study directly takes advantage of recently available remote sensing products, and attributes the improved regional model simulation to proper LAI specification, which leads to adequate land/atmosphere interactions.

  8. Large-scale Validation of AMIP II Land-surface Simulations: Preliminary Results for Ten Models

    SciTech Connect

    Phillips, T J; Henderson-Sellers, A; Irannejad, P; McGuffie, K; Zhang, H

    2005-12-01

    This report summarizes initial findings of a large-scale validation of the land-surface simulations of ten atmospheric general circulation models that are entries in phase II of the Atmospheric Model Intercomparison Project (AMIP II). This validation is conducted by AMIP Diagnostic Subproject 12 on Land-surface Processes and Parameterizations, which is focusing on putative relationships between the continental climate simulations and the associated models' land-surface schemes. The selected models typify the diversity of representations of land-surface climate that are currently implemented by the global modeling community. The current dearth of global-scale terrestrial observations makes exacting validation of AMIP II continental simulations impractical. Thus, selected land-surface processes of the models are compared with several alternative validation data sets, which include merged in-situ/satellite products, climate reanalyses, and off-line simulations of land-surface schemes that are driven by observed forcings. The aggregated spatio-temporal differences between each simulated process and a chosen reference data set then are quantified by means of root-mean-square error statistics; the differences among alternative validation data sets are similarly quantified as an estimate of the current observational uncertainty in the selected land-surface process. Examples of these metrics are displayed for land-surface air temperature, precipitation, and the latent and sensible heat fluxes. It is found that the simulations of surface air temperature, when aggregated over all land and seasons, agree most closely with the chosen reference data, while the simulations of precipitation agree least. In the latter case, there also is considerable inter-model scatter in the error statistics, with the reanalyses estimates of precipitation resembling the AMIP II simulations more than to the chosen reference data. In aggregate, the simulations of land-surface latent and sensible

  9. Land Surface Albedo from MERIS Reflectances Using MODIS Directional Factors

    NASA Technical Reports Server (NTRS)

    Schaaf, Crystal L. B.; Gao, Feng; Strahler, Alan H.

    2004-01-01

    MERIS Level 2 surface reflectance products are now available to the scientific community. This paper demonstrates the production of MERIS-derived surface albedo and Nadir Bidirectional Reflectance Distribution Function (BRDF) adjusted reflectances by coupling the MERIS data with MODIS BRDF products. Initial efforts rely on the specification of surface anisotropy as provided by the global MODIS BRDF product for a first guess of the shape of the BRDF and then make use all of the coincidently available, partially atmospherically corrected, cloud cleared, MERIS observations to generate MERIS-derived BRDF and surface albedo quantities for each location. Comparisons between MODIS (aerosol-corrected) and MERIS (not-yet aerosol-corrected) surface values from April and May 2003 are also presented for case studies in Spain and California as well as preliminary comparisons with field data from the Devil's Rock Surfrad/BSRN site.

  10. Long-term change in surface air temperature over Eurasian continent and possible contribution from land-surface conditions.

    NASA Astrophysics Data System (ADS)

    Kim, K.; Jeong, J. H.; Shim, T.

    2015-12-01

    Summertime heat wave over Eurasia is induced by various climatic factors. As internal and external factors are changing under an abrupt climate change, the variability of heat waves exhibits radical changes. In this study, the long-term change in heat wave characteristics over Eurasia for the last several decades was examined and the impact of land-atmosphere interaction modulated by soil moisture variability on the change was investigated. Through the empirical orthogonal functions(EOF) analysis, the principle spatio-temporal pattern of Eurasian heat wave during July-August was objectively detected. The leading pattern (1st EOF mode) of the variability was found be an overall increase in heat waves over eastern Europe and east Asia (Mongol to northern part of China), which seems to be associated mainly with the global warming signal but with interannual variability as well. Through performing JULES(Joint UK Land Environment Simulator) land surface model simulation forced with observational atmospheric forcings, soil moisture and energy flux at surface were estimated, and the impacts of land-atmosphere interaction on the heat wave variability was investigated based on the estimated land surface variables and temperature observations. It is found that there is a distinct dry soil condition accompanying with East Asian heat waves. The dry condition leads to an increase in sensible heat flux from land surface to atmosphere and resulting near-surface warming, which is followed by warm-core high - a typical characteristics of a heatwave sustained by land-atmosphere interaction. This result is consistent with an distinct increase in heatwave in recent years. By using the hindcast of long-range prediction model of KMA, GloSea5, the seasonal predictability of heatwave was examined. GloSea5 reasonably well simulates the spatial pattern of Eurasian heatwaves variability found in observations but shows modest skill in simulating accurate year-to-year variability. This result

  11. The Mars Microprobe Mission: Advanced Micro-Avionics for Exploration Surface

    NASA Technical Reports Server (NTRS)

    Blue, Randel

    2000-01-01

    The Mars Microprobe Mission is the second spacecraft developed as part of the New Millennium Program deep space missions. The objective of the Microprobe Project is to demonstrate the applicability of key technologies for future planetary missions by developing two probes for deployment on Mars. The probes are designed with a single stage entry, descent, and landing system and impact the Martian surface at speeds of approximately 200 meters per second. The microprobes are composed of two main sections, a forebody section that penetrates to a depth below the Martian surface of 0.5 to 2 meters, and an aftbody section that remains on the surface. Each probe system consists of a number of advanced technology components developed specifically for this mission. These include a non-erosive aeroshell for entry into. the atmosphere, a set of low temperature batteries to supply probe power, an advanced microcontroller to execute the mission sequence, collect the science data, and react to possible system fault conditions, a telecommunications subsystem implemented on a set of custom integrated circuits, and instruments designed to provide science measurements from above and below the Martian surface. All of the electronic components have been designed and fabricated to withstand the severe impact shock environment and to operate correctly at predicted temperatures below -100 C.

  12. Ongoing land use change exacerbates tropical South American drought by sea surface temperature variability

    NASA Astrophysics Data System (ADS)

    Lee, J.; Lintner, B. R.; Boyce, C. K.; Lawrence, P.

    2011-12-01

    Observations of tropical South American precipitation over the last three decades indicate an increasing rainfall trend to the north and a decreasing trend to the south. Given that tropical South America has experienced significant land use change over the same period, it is of interest to assess the extent to which changing land use may have contributed to the precipitation trends. Simulations of the National Center for Atmospheric Research Community Atmosphere Model (NCAR CAM) analyzed here suggest a non-negligible impact of land use on this precipitation behavior. While forcing the model by imposed historical sea surface temperatures (SSTs) alone produces a plausible north-south precipitation dipole over South America, NCAR CAM substantially underestimates the magnitude of the observed southern decrease in rainfall unless forcing associated with human-induced land use change is included. The impact of land use change on simulated precipitation occurs primarily during the local dry season and in regions of relatively low annual-mean rainfall, as the incidence of very low monthly-mean accumulations (<10 mm/month) increases significantly when land use change is imposed. Land use change also contributes to the simulated temperature increase by increasing sensible heat flux from the land surface. Moving forward, continuing pressure from deforestation in tropical South America will likely increase the occurrence of significant drought beyond what would be expected by anthropogenic warming alone and in turn compound biodiversity decline from habitat loss and fragmentation.

  13. Advances in cell surface glycoengineering reveal biological function.

    PubMed

    Nischan, Nicole; Kohler, Jennifer J

    2016-08-01

    Cell surface glycans are critical mediators of cell-cell, cell-ligand, and cell-pathogen interactions. By controlling the set of glycans displayed on the surface of a cell, it is possible to gain insight into the biological functions of glycans. Moreover, control of glycan expression can be used to direct cellular behavior. While genetic approaches to manipulate glycosyltransferase gene expression are available, their utility in glycan engineering has limitations due to the combinatorial nature of glycan biosynthesis and the functional redundancy of glycosyltransferase genes. Biochemical and chemical strategies offer valuable complements to these genetic approaches, notably by enabling introduction of unnatural functionalities, such as fluorophores, into cell surface glycans. Here, we describe some of the most recent developments in glycoengineering of cell surfaces, with an emphasis on strategies that employ novel chemical reagents. We highlight key examples of how these advances in cell surface glycan engineering enable study of cell surface glycans and their function. Exciting new technologies include synthetic lipid-glycans, new chemical reporters for metabolic oligosaccharide engineering to allow tandem and in vivo labeling of glycans, improved chemical and enzymatic methods for glycoproteomics, and metabolic glycosyltransferase inhibitors. Many chemical and biochemical reagents for glycan engineering are commercially available, facilitating their adoption by the biological community.

  14. Diagnosing coupled watershed processes using a fully-coupled groundwater, land-surface, surface water and mesoscale atmospheric model

    NASA Astrophysics Data System (ADS)

    Maxwell, R. M.; Kollet, S. J.; Chow, F. K.

    2007-12-01

    A variably-saturated groundwater flow model with an integrated overland flow component, a land-surface model and a mesoscale atmospheric model is used to examine the interplay between coupled water and energy processes. These processes are influenced by land-surface topography and subsurface heterogeneity. This parallel, integrated model simulates spatial variations in land-surface forcing driven by three-dimensional (3D) atmospheric and subsurface components. Spatial statistics are used to demonstrate spatial and temporal correlations between surface and lower atmospheric variables and water table depth. These correlations are particularly strong during times when the land surface temperatures trigger shifts in wind behavior, such as during early morning surface heating. Additionally, spectral transforms of subsurface arrival times are computed using a transient Lagrangian transport simulation. Macrodispersion is used to mimic the effects of subsurface heterogeneity for a range of Peclet numbers. The slopes of these transforms indicate fractal scaling of this system over a range of timescales. All of these techniques point to importance of realistically representing coupled processes and the need to understand and diagnose these processes in nature. This work was conducted under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory (LLNL) under contract W-7405-Eng-48. This project was funded by the Laboratory Directed Research and Development Program at LLNL

  15. Evaluation of surface properties and atmospheric disturbances caused by post-dam alterations of land use/land cover

    NASA Astrophysics Data System (ADS)

    Woldemichael, A. T.; Hossain, F.; Pielke, R., Sr.

    2014-09-01

    This study adopted a differential land-use/land-cover (LULC) analysis to evaluate dam-triggered land-atmosphere interactions for a number of LULC scenarios. Two specific questions were addressed: (1) can dam-triggered LULC heterogeneities modify surface and energy budget, which, in turn, change regional convergence and precipitation patterns? (2) How extensive is the modification in surface moisture and energy budget altered by dam-triggered LULC changes occurring in different climate and terrain features? The Regional Atmospheric Modeling System (RAMS, version 6.0) was set up for two climatologically and topographically contrasting regions: the American River watershed (ARW), located in California, and the Owyhee River watershed (ORW), located in eastern Oregon. For the selected atmospheric river precipitation event of 29 December 1996 to 3 January 1997, simulations of three pre-defined LULC scenarios are performed. The definition of the scenarios are (1) the "control" scenario, representing the contemporary land use, (2) the "pre-dam" scenario, representing the natural landscape before the construction of the dams and (3) the "non-irrigation" scenario, representing the condition where previously irrigated landscape in the control is transformed to the nearby land-use type. Results indicated that the ARW energy and moisture fluxes were more extensively affected by dam-induced changes in LULC than the ORW. Both regions, however, displayed commonalities in the modification of land-atmosphere processes due to LULC changes, with the control-non-irrigation scenario creating more change than the control-pre-dam scenarios. These commonalities were: (1) the combination of a decrease in temperature (up to 0.15 °C) and an increase at dew point (up to 0.25 °C) was observed; (2) there was a larger fraction of energy partitioned to latent heat flux (up to 10 W m-2) that increased the amount of water vapor in the atmosphere and resulted in a larger convective available

  16. Evaluation of surface properties and atmospheric disturbances caused by post-dam alterations of land-use/land-cover

    NASA Astrophysics Data System (ADS)

    Woldemichael, A. T.; Hossain, F.; Pielke, R., Sr.

    2014-05-01

    This study adopted a differential land-use/land-cover (LULC) analysis to evaluate dam-triggered land-atmosphere interactions for a number of LULC scenarios. Two specific questions were addressed: (1) can dam-triggered LULC heterogeneities modify surface and energy budget which, in turn, change regional convergence and precipitation patterns? and (2) how extensive is the modification in surface moisture and energy budget altered by dam-triggered LULC changes occurring in different climate and terrain features? The Regional Atmospheric Modeling System (RAMS, version 6.0) was set up for two climatologically and topographically contrasting regions: the American River Watershed (ARW) located in California and the Owyhee River Watershed (ORW) located in eastern Oregon. For the selected atmospheric river precipitation event of 29 December 1996 to 3 January 1997, simulations of three pre-defined LULC scenarios are performed. The definition of the scenarios are: (1) the control scenario representing the contemporary land-use, (2) the pre-dam scenario representing the natural landscape before the construction of the dams and (3) the non-irrigation scenario representing the condition where previously irrigated landscape in the control is transformed to the nearby land-use type. Results indicated that the ARW energy and moisture fluxes were more extensively affected by dam-induced changes in LULC than the ORW. Both regions, however, displayed commonalities in the modification of land-atmosphere processes due to LULC changes, with the control-non-irrigation scenario creating more change than the control-pre-dam scenarios. These commonalities were: (1) the combination of a decrease in temperature (up to 0.15 °C) and an increase in dewpoint (up to 0.25 °C) was observed, (2) there was a larger fraction of energy partitioned to latent heat flux (up to 10 W m-2) that increased the amount of water vapor to the atmosphere and resulted in a larger convective available potential

  17. Advances in targeting cell surface signalling molecules for immune modulation

    PubMed Central

    Yao, Sheng; Zhu, Yuwen; Chen, Lieping

    2013-01-01

    The past decade has witnessed a surge in the development of immunomodulatory approaches to combat a broad range of human diseases, including cancer, viral infections, autoimmunity and inflammation as well as in the prevention of transplant rejection. Immunomodulatory approaches mostly involve the use of monoclonal antibodies or recombinant fusion proteins that target cell surface signalling molecules on immune cells to drive immune responses towards the desired direction. Advances in our understanding of the human immune system, along with valuable lessons learned from the first generation of therapeutic biologics, are aiding the design of the next generation of immunomodulatory biologics with better therapeutic efficacy, minimized adverse effects and long-lasting clinical benefit. The recent encouraging results from antibodies targeting programmed cell death protein 1 (PD1) and B7 homolog 1 (B7H1; also known as PDL1) for the treatment of various advanced human cancers show that immunomodulatory therapy has come of age. PMID:23370250

  18. Laser-Guided Autonomous Landing of a Quadrotor UAV on an Inclined Surface

    NASA Astrophysics Data System (ADS)

    Dougherty, John A.

    This thesis presents measurement, estimation, and control schemes to aid a quadrotor unmanned aerial vehicle (UAV) in landing on a flat, inclined surface without prior knowledge of the surface's inclination. The system uses a single CMOS camera and several inexpensive laser modules for onboard sensing to measure the distance to and orientation of a landing surface. A nonlinear least squares estimation scheme yields the altitude of the quadrotor and the normal vector defining the ground plane. This information is used to design a hybrid landing trajectory composed of a position tracking phase and an attitude tracking phase. A geometric nonlinear control system is used during each phase and ensures that the quadrotor's attitude is aligned to the inclination of the ground surface at touchdown. A quadrotor is developed from the ground up to test the in-flight measurement process and to execute landing trajectories on an inclined surface. Experimental results demonstrate the quadrotor's ability to accurately estimate altitude and ground plane orientation during flight, and numerical simulations of landing trajectories for various surface inclinations are validated by experimental results up to a maximum inclination of thirty degrees.

  19. Advanced Land use Classification Considering Intra-annual Cropping patterns and Urbanization processes as a Contribution to Improve Knowledge base for Water Management.

    NASA Astrophysics Data System (ADS)

    Kumar, N.; Tischbein, B.; Beg, M. K.

    2014-12-01

    Land use and its spatial pattern and dynamics strongly influence water resources and water demand. Therefore, integrated water resources management coordinating water supply and demand is using modeling tools in order to assess the impact of land use changes on the water balance and to conceive infrastructural and operational measures to cope with these impacts. As a consequence, the appropriateness of water management measures depends on the reliability of the output gained by the modeling tools which in turn is highly determined by the capability of the models and the quality of model inputs. This research combines the Soil and Water Assessment Tool (SWAT) and an advanced procedure for spatio-temporal detection of land use dynamics and irrigation in the Upper Kharun basin in the Chhattisgarh State in India. An on-screen visual digitization technique using the Landsat satellite images and their derivatives (NDVI and tasseled cap indices) were employed for land use classification. The land use maps prepared at different time steps within a year can be combined to produce a single multi-temporal land use classification. This approach captures and integrates all the major variations within a year in a single map and hence better represents an area with multiple crop rotations and different levels of urbanization. Urbanization and intensification of irrigation by increasing use of groundwater are major land use processes at the global scale as well as in the study region. The study reveals that an increasing pumping rate of groundwater for irrigation is the main reason for decreasing the groundwater contribution to streamflow and subsequently a lowering in discharge and water yield. On the other hand, annual surface runoff is increased significantly by an expansion in built up areas over the decades in the study area. This information (i) enhances the understanding of land use changes and their relevant drivers, and (ii) facilitates the introduction of best water and

  20. An Integrated Snow Radiance and Snow Physics Modeling Framework for Cold Land Surface Modeling

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.; Tedesco, Marco

    2006-01-01

    Recent developments in forward radiative transfer modeling and physical land surface modeling are converging to allow the assembly of an integrated snow/cold lands modeling framework for land surface modeling and data assimilation applications. 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. Together these form a flexible framework for self-consistent remote sensing and water/energy cycle studies. In this paper we will describe the elements and the integration plan. Each element of this framework is modular so the choice of element can be tailored to match the emphasis of a particular study. For example, within our framework, four choices of a FRTM are available to simulate the brightness temperature of snow: Two models are available to model the physical evolution of the snowpack and underlying soil, and two models are available to handle the water/energy balance at the land surface. Since the framework is modular, other models-physical or statistical--can be accommodated, too. 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 at the NASA Goddard Space Flight Center. The advantages of such an integrated modular framework built on the LIS will be described through examples-e.g., studies to analyze snow field experiment observations, and simulations of future satellite missions for snow and cold land processes.

  1. Status of remote sensing algorithms for estimation of land surface state parameters

    SciTech Connect

    Hall, F.G.; Engman, E.T.; Townshend, J.R.

    1995-01-01

    Ecosystem process, biosphere-atmosphere transfer, and carbon exchange models all require parameterization of the land surface, including land vegetation cover and soil moisture. Although not yet a demonstrated global capability, the most feasible method for obtaining these parameters and updating them periodically, is satellite remote sensing. In this paper the authors will summarize their understanding of the desired land surface parameters, including soil moisture, and provide an assessment of the state of the art of surface state remote sensing algorithms to infer those parameters on a global basis. First, the authors will consider (a) modeling requirements for land cover parameters, including vegetation community composition and biophysical parameters, for example, leaf area index (LAI), biomass density, fraction of photo-synthetically active radiation (Fpar) absorbed by the vegetated land surface, and (b) modeling requirements for soil moisture. The authors will then review the status of remote sensing algorithms for obtaining these parameters and examine a number of issues involved in the global implementation and testing of these algorithms. Finally, they will look at future needs to make global mapping of land cover parameters a reality.

  2. Nonpoint sources of volatile organic compounds in urban areas - Relative importance of land surfaces and air

    USGS Publications Warehouse

    Lopes, T.J.; Bender, D.A.

    1998-01-01

    Volatile organic compounds (VOCs) commonly detected in urban waters across the United States include gasoline-related compounds (e.g. toluene, xylene) and chlorinated compounds (e.g. chloroform, tetrachloroethane [PCE], trichloroethene [TCE]). Statistical analysis of observational data and results of modeling the partitioning of VOCs between air and water suggest that urban land surfaces are the primary nonpoint source of most VOCs. Urban air is a secondary nonpoint source, but could be an important source of the gasoline oxygenate methyl-tert butyl ether (MTBE). Surface waters in urban areas would most effectively be protected by controlling land-surface sources.

  3. Spectral emissivity measurements of land-surface materials and related radiative transfer simulations

    NASA Technical Reports Server (NTRS)

    Wan, Z.; Ng, D.; Dozier, J.

    1994-01-01

    Spectral radiance measurements have been made in the laboratory and in the field for deriving spectral emissivities of some land cover samples with a spectroradiometer and an auxiliary radiation source in the wavelength range 2.5-14.5 micrometers. A easy and quick four-step method (four steps to measure the sample and a diffuse reflecting plate surface under sunshine and shadowing conditions, respectively) has been used for simultaneous determination of surface temperature and emissivity. We emphasized in-situ measurements in combination with radiative transfer simulations, and an error analysis for basic assumptions in deriving spectral emissivity of land-surface samples from thermal infrared measurements.

  4. Characterizing Mediterranean Land Surfaces as Component of the Regional Climate System by Remote Sensing

    NASA Technical Reports Server (NTRS)

    Bolle, H.-J.; Koslowsky, D.; Menenti, M.; Nerry, F.; Otterman, Joseph; Starr, D.

    1998-01-01

    Extensive areas in the Mediterranean region are subject to land degradation and desertification. The high variability of the coupling between the surface and the atmosphere affects the regional climate. Relevant surface characteristics, such as spectral reflectance, surface emissivity in the thermal-infrared region, and vegetation indices, serve as "primary" level indicators for the state of the surface. Their spatial, seasonal and interannual variability can be monitored from satellites. Using relationships between these primary data and combining them with prior information about the land surfaces (such as topography, dominant soil type, land use, collateral ground measurements and models), a second layer of information is built up which specifies the land surfaces as a component of the regional climate system. To this category of parameters which are directly involved in the exchange of energy, momentum and mass between the surface and the atmosphere, belong broadband albedo, thermodynamic surface temperature, vegetation types, vegetation cover density, soil top moisture, and soil heat flux. Information about these parameters finally leads to the computation of sensible and latent heat fluxes. The methodology was tested with pilot data sets. Full resolution, properly calibrated and normalized NOAA-AVHRR multi-annual primary data sets are presently compiled for the whole Mediterranean area, to study interannual variability and longer term trends.

  5. A MODELING APPROACH FOR ESTIMATING WATERSHED IMPERVIOUS SURFACE AREA FROM NATIONAL LAND COVER DATA 92

    EPA Science Inventory

    We used National Land Cover Data 92 (NLCD92), vector impervious surface data, and raster GIS overlay methods to derive impervious surface coefficients per NLCD92 class in portions of the Nfid-Atlantic physiographic region. The methods involve a vector to raster conversion of the ...

  6. Wireless Channel Characterization in the 5 GHz Microwave Landing System Extension Band for Airport Surface Areas

    NASA Technical Reports Server (NTRS)

    Matolak, David W.

    2007-01-01

    In this project final report, entitled "Wireless Channel Characterization in the 5 GHz Microwave Landing System Extension Band for Airport Surface Areas," we provide a detailed description and model representation for the wireless channel in the airport surface environment in this band. In this executive summary, we review report contents, describe the achieved objectives and major findings, and highlight significant conclusions and recommendations.

  7. High resolution land surface geophysical parameters estimation from ALOS PALSAR data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High resolution land surface geophysical products, such as soil moisture, surface roughness and vegetation water content, are essential for a variety of applications ranging from water management to regional climate predictions. In India high resolution geophysical products, in particular soil moist...

  8. 29 CFR 1918.32 - Stowed cargo and temporary landing surfaces.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Stowed cargo and temporary landing surfaces. 1918.32 Section 1918.32 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Working Surfaces § 1918.32 Stowed cargo and temporary...

  9. Generating daily land surface temperature at Landsat resolution by fusing Landsat and MODIS data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface temperature (LST) is a crucial parameter in investigating environmental, ecological processes and climate change at various scales, and is also valuable in the studies of evapotranspiration, soil moisture conditions, surface energy balance, and urban heat islands. These studies require ...

  10. Improving satellite-based rainfall estimates over land using spaceborne surface soil moisture retrievals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over land, remotely-sensed surface soil moisture and precipitation accumulation retrievals contain complementary information that can be exploited for the mutual benefit of both products. Here a Kalman filtering based tool is developed that utilizes a time series of spaceborne surface soil moisture ...

  11. The CEOS-Land Surface Imaging Constellation Portal for GEOSS: A resource for land surface imaging system information and data access

    USGS Publications Warehouse

    Holm, Thomas; Gallo, Kevin P.; Bailey, Bryan

    2010-01-01

    The Committee on Earth Observation Satellites is an international group that coordinates civil space-borne observations of the Earth, and provides the space component of the Global Earth Observing System of Systems (GEOSS). The CEOS Virtual Constellations concept was implemented in an effort to engage and coordinate disparate Earth observing programs of CEOS member agencies and ultimately facilitate their contribution in supplying the space-based observations required to satisfy the requirements of the GEOSS. The CEOS initially established Study Teams for four prototype constellations that included precipitation, land surface imaging, ocean surface topography, and atmospheric composition. The basic mission of the Land Surface Imaging (LSI) Constellation [1] is to promote the efficient, effective, and comprehensive collection, distribution, and application of space-acquired image data of the global land surface, especially to meet societal needs of the global population, such as those addressed by the nine Group on Earth Observations (GEO) Societal Benefit Areas (SBAs) of agriculture, biodiversity, climate, disasters, ecosystems, energy, health, water, and weather. The LSI Constellation Portal is the result of an effort to address important goals within the LSI Constellation mission and provide resources to assist in planning for future space missions that might further contribute to meeting those goals.

  12. Advanced construction management for lunar base construction - Surface operations planner

    NASA Technical Reports Server (NTRS)

    Kehoe, Robert P.

    1992-01-01

    The study proposes a conceptual solution and lays the framework for developing a new, sophisticated and intelligent tool for a lunar base construction crew to use. This concept integrates expert systems for critical decision making, virtual reality for training, logistics and laydown optimization, automated productivity measurements, and an advanced scheduling tool to form a unique new planning tool. The concept features extensive use of computers and expert systems software to support the actual work, while allowing the crew to control the project from the lunar surface. Consideration is given to a logistics data base, laydown area management, flexible critical progress scheduler, video simulation of assembly tasks, and assembly information and tracking documentation.

  13. Advances in surface plasmon resonance-based high throughput biochips

    NASA Astrophysics Data System (ADS)

    Zhang, San-Jun; Berguiga, Lotfi; Elezgaray, Juan; Hugo, Nicolas; Li, Wen-Xue; Roland, Thibault; Zeng, He-Ping; Argoul, Francoise

    2009-12-01

    This article reviews our recent advances in surface plasmon resonance (SPR) based biochips. It includes four issues, which are the preparation and characterization of high quality gold film, the preparation and characterization of self-assembled monolayer (SAM), dynamics of DNA adsorption on SAMs, and SPR-based microscopies. Numerous topics related to SPR, such as, the modeling of SPR by transmission matrix, effective medium theory, applications of SPR in biology, and SPR-based novel microscopies, are discussed. A novel electrochemical technique, which is extremely useful for the preparation and characterization of high quality SAMs, is also discussed.

  14. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Hanson, J.S.; Diao, J.; Harris, G.H.; De, A.; Sotillo, F. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, W.; Zou, Y.; Chen, W. ); Choudhry, V.; Shea, S.; Ghosh, A.; Sehgal, R. )

    1992-03-01

    The initial goal of the research project was to develop methods of coal surface control in advanced froth flotation to achieve 90% pyritic sulfur rejection, while operating at Btu recoveries above 90% based on run-of-mine quality coal. Moreover, the technology is to concomitantly reduce the ash content significantly (to six percent or less) to provide a high-quality fuel to the boiler (ash removal also increases Btu content, which in turn decreases a coal's emission potential in terms of lbs SO{sub 2}/million Btu). (VC)

  15. Is land surface processes representation a possible weak link in current Regional Climate Models?

    NASA Astrophysics Data System (ADS)

    Davin, Edouard L.; Maisonnave, Eric; Seneviratne, Sonia I.

    2016-07-01

    The representation of land surface processes and fluxes in climate models critically affects the simulation of near-surface climate over land. Here we present an evaluation of COSMO-CLM2, a model which couples the COSMO-CLM Regional Climate Model to the Community Land Model (CLM4.0). CLM4.0 provides a more detailed representation of land processes compared to the native land surface scheme in COSMO-CLM. We perform historical reanalysis-driven simulations over Europe with COSMO-CLM2 following the EURO-CORDEX intercomparison protocol. We then evaluate simulations performed with COSMO-CLM2, the standard COSMO-CLM and other EURO-CORDEX RCMs against various observational datasets of temperature, precipitation and surface fluxes. Overall, the results indicate that COSMO-CLM2 outperforms both the standard COSMO-CLM and the other EURO-CORDEX models in simulating sensible, latent and surface radiative fluxes as well as 2-meter temperature across different seasons and regions. The performance improvement is particularly strong for turbulent fluxes and for daily maximum temperatures and more modest for daily minimum temperature, suggesting that land surface processes affect daytime even more than nighttime conditions. COSMO-CLM2 also alleviates a long-standing issue of overestimation of interannual summer temperature variability present in most EURO-CORDEX RCMs. Finally, we show that several factors contribute to these improvements, including the representation of evapotranspiration, radiative fluxes and ground heat flux. Overall, these results demonstrate that land processes represent a key area of development to tackle current deficiencies in RCMs.

  16. Sensitivity of biogenic volatile organic compounds to land surface parameterizations and vegetation distributions in California

    NASA Astrophysics Data System (ADS)

    Zhao, Chun; Huang, Maoyi; Fast, Jerome D.; Berg, Larry K.; Qian, Yun; Guenther, Alex; Gu, Dasa; Shrivastava, Manish; Liu, Ying; Walters, Stacy; Pfister, Gabriele; Jin, Jiming; Shilling, John E.; Warneke, Carsten

    2016-05-01

    Current climate models still have large uncertainties in estimating biogenic trace gases, which can significantly affect atmospheric chemistry and secondary aerosol formation that ultimately influences air quality and aerosol radiative forcing. These uncertainties result from many factors, including uncertainties in land surface processes and specification of vegetation types, both of which can affect the simulated near-surface fluxes of biogenic volatile organic compounds (BVOCs). In this study, the latest version of Model of Emissions of Gases and Aerosols from Nature (MEGAN v2.1) is coupled within the land surface scheme CLM4 (Community Land Model version 4.0) in the Weather Research and Forecasting model with chemistry (WRF-Chem). In this implementation, MEGAN v2.1 shares a consistent vegetation map with CLM4 for estimating BVOC emissions. This is unlike MEGAN v2.0 in the public version of WRF-Chem that uses a stand-alone vegetation map that differs from what is used by land surface schemes. This improved modeling framework is used to investigate the impact of two land surface schemes, CLM4 and Noah, on BVOCs and examine the sensitivity of BVOCs to vegetation distributions in California. The measurements collected during the Carbonaceous Aerosol and Radiative Effects Study (CARES) and the California Nexus of Air Quality and Climate Experiment (CalNex) conducted in June of 2010 provided an opportunity to evaluate the simulated BVOCs. Sensitivity experiments show that land surface schemes do influence the simulated BVOCs, but the impact is much smaller than that of vegetation distributions. This study indicates that more effort is needed to obtain the most appropriate and accurate land cover data sets for climate and air quality models in terms of simulating BVOCs, oxidant chemistry and, consequently, secondary organic aerosol formation.

  17. Use of MODIS Land and Sea Surface Temperatures to Initialize Mesoscale Models

    NASA Technical Reports Server (NTRS)

    Arnold, James E. (Technical Monitor); Lapenta, William M.; Haines, Stephanie; Jedlovec, Gary; Mackaro, Scott

    2003-01-01

    As computer power continues to increase, mesoscale models are initialized at all hours of the day and continue to be run at higher and higher spatial resolutions. As a result, initializing land surface temperature can be problematic. The majority of research-based models are initialized at 00 and 12 UTC when upper air observations and reanalysis fields are available. The landsea surface temperatures are then set equal to the two-meter air temperature produced by the preprocessor analysis system. This particular procedure might be valid in the early morning hours just prior to sunrise, but it becomes less valid during the remainder of the diurnal cycle. Operational models, such as the Rapid Update Cycle run at the National Centers for Environmental Prediction (NCEP), are initialized every hour on a daily basis. This presents a unique challenge to the initial specification of the land temperature, especially during the first several hours of the solar heating cycle when land and overlying air temperatures are far from being the same. Another issue that needs to be addressed is the spatial variability of land surface temperature. By early next year, the NCEP operational Eta model will be employed at 8 km resolution. Methods to accurately specify the initial land surface temperature at such high resolution need to be explored. This paper presents the results of using data from the NASA Moderate Imaging Sensor aboard the TERRA Satellite to initialize land and sea surface temperatures within the Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) 5'th generation Mesoscale Model (MM5). We have simulated a northern Gulf Coast sea breeze case to demonstrate the utility of using the MODIS data to initialize both the land and sea surface temperature fields. Model grid configurations of 12-, 4-, and l-km are employed.

  18. Preface paper to the Semi-Arid Land-Surface-Atmosphere (SALSA) Program special issue

    USGS Publications Warehouse

    Goodrich, D.C.; Chehbouni, A.; Goff, B.; MacNish, B.; Maddock, T.; Moran, S.; Shuttleworth, W.J.; Williams, D.G.; Watts, C.; Hipps, L.H.; Cooper, D.I.; Schieldge, J.; Kerr, Y.H.; Arias, H.; Kirkland, M.; Carlos, R.; Cayrol, P.; Kepner, W.; Jones, B.; Avissar, R.; Begue, A.; Bonnefond, J.-M.; Boulet, G.; Branan, B.; Brunel, J.P.; Chen, L.C.; Clarke, T.; Davis, M.R.; DeBruin, H.; Dedieu, G.; Elguero, E.; Eichinger, W.E.; Everitt, J.; Garatuza-Payan, J.; Gempko, V.L.; Gupta, H.; Harlow, C.; Hartogensis, O.; Helfert, M.; Holifield, C.; Hymer, D.; Kahle, A.; Keefer, T.; Krishnamoorthy, S.; Lhomme, J.-P.; Lagouarde, J.-P.; Lo, Seen D.; Luquet, D.; Marsett, R.; Monteny, B.; Ni, W.; Nouvellon, Y.; Pinker, R.; Peters, C.; Pool, D.; Qi, J.; Rambal, S.; Rodriguez, J.; Santiago, F.; Sano, E.; Schaeffer, S.M.; Schulte, M.; Scott, R.; Shao, X.; Snyder, K.A.; Sorooshian, S.; Unkrich, C.L.; Whitaker, M.; Yucel, I.

    2000-01-01

    The Semi-Arid Land-Surface-Atmosphere Program (SALSA) is a multi-agency, multi-national research effort that seeks to evaluate the consequences of natural and human-induced environmental change in semi-arid regions. The ultimate goal of SALSA is to advance scientific understanding of the semi-arid portion of the hydrosphere-biosphere interface in order to provide reliable information for environmental decision making. SALSA approaches this goal through a program of long-term, integrated observations, process research, modeling, assessment, and information management that is sustained by cooperation among scientists and information users. In this preface to the SALSA special issue, general program background information and the critical nature of semi-arid regions is presented. A brief description of the Upper San Pedro River Basin, the initial location for focused SALSA research follows. Several overarching research objectives under which much of the interdisciplinary research contained in the special issue was undertaken are discussed. Principal methods, primary research sites and data collection used by numerous investigators during 1997-1999 are then presented. Scientists from about 20 US, five European (four French and one Dutch), and three Mexican agencies and institutions have collaborated closely to make the research leading to this special issue a reality. The SALSA Program has served as a model of interagency cooperation by breaking new ground in the approach to large scale interdisciplinary science with relatively limited resources.

  19. Land surface model calibration through microwave data assimilation for improving soil moisture simulations

    NASA Astrophysics Data System (ADS)

    Yang, Kun; Zhu, La; Chen, Yingying; Zhao, Long; Qin, Jun; Lu, Hui; Tang, Wenjun; Han, Menglei; Ding, Baohong; Fang, Nan

    2016-02-01

    Soil moisture is a key variable in climate system, and its accurate simulation needs effective soil parameter values. Conventional approaches may obtain soil parameter values at point scale, but they are costly and not efficient at grid scale (10-100 km) of current climate models. This study explores the possibility to estimate soil parameter values by assimilating AMSR-E (Advanced Microwave Scanning Radiometer for Earth Observing System) brightness temperature (TB) data. In the assimilation system, the TB is simulated by the coupled system of a land surface model (LSM) and a radiative transfer model (RTM), and the simulation errors highly depend on parameters in both the LSM and the RTM. Thus, sensitive soil parameters may be inversely estimated through minimizing the TB errors. A crucial step for the parameter estimation is made to suppress the contamination of uncertainties in atmospheric forcing data. The effectiveness of the estimated parameter values is evaluated against intensive measurements of soil parameters and soil moisture in three grasslands of the Tibetan Plateau and the Mongolian Plateau. The results indicate that this satellite data-based approach can improve the data quality of soil porosity, a key parameter for soil moisture modeling, and LSM simulations with the estimated parameter values reasonably reproduce the measured soil moisture. This demonstrates it is feasible to calibrate LSMs for soil moisture simulations at grid scale by assimilating microwave satellite data, although more efforts are expected to improve the robustness of the model calibration.

  20. Towards a History of NASA Applied Sciences: Making Land Surface Data Useful, 1974-2010

    NASA Astrophysics Data System (ADS)

    Conway, E. M.; Yuen, K.

    2012-12-01

    To date, there is very little historical work on either the NASA Applications Program, or its successor, the NASA Applied Science program. The one relevant, fully-fledged history is of the Landsat program through 1980, which was carried out under the old, long defunct, NASA Office of Applications. Much more historical work can be done on these two programs, and this paper will make a small contribution towards a fuller history by tracing the evolution of the Normalized Difference Vegetation Index and its migration from research product into a variety of different applications. Derived not from Landsat but from the Advanced Very High Resolution Radiometer on the NOAA series of polar orbiting weather satellites, the NDVI dataset originated in ground-based research carried out during the 1970s. Once the AVHRR-derived version was validated in the mid-1980s, it immediately attracted attention from a variety of organizations interested in using it for their own purposes—famine warning and relief, locust warning, etc. It also became an important input to land surface models, which themselves evolved during this period to become the basis of still other applications. This paper will offer an historical analysis of the process by which NDVI became routinized, utilitarian, and deeply embedded in the products of other organizations.

  1. Validation of the modified Becker's split-window approach for retrieving land surface temperature from AVHRR

    NASA Astrophysics Data System (ADS)

    Quan, Weijun; Chen, Hongbin; Han, Xiuzhen; Ma, Zhiqiang

    2015-10-01

    To further verify the modified Becker's split-window approach for retrieving land surface temperature (LST) from long-term Advanced Very High Resolution Radiometer (AVHRR) data, a cross-validation and a radiance-based (R-based) validation are performed and examined in this paper. In the cross-validation, 3481 LST data pairs are extracted from the AVHRR LST product retrieved with the modified Becker's approach and compared with the Moderate Resolution Imaging Spectroradiometer (MODIS) LST product (MYD11A1) for the period 2002-2008, relative to the positions of 548 weather stations in China. The results show that in most cases, the AVHRR LST values are higher than the MYD11A1. When the AVHRR LSTs are adjusted with a linear regression, the values are close to the MYD11A1, showing a good linear relationship between the two datasets ( R 2 = 0.91). In the R-based validation, comparison is made between AVHRR LST retrieved from the modified Becker's approach and the inversed LST from the Moderate Resolution Transmittance Model (MODTRAN) consolidated with observed temperature and humidity profiles at four radiosonde stations. The results show that the retrieved AVHRR LST deviates from the MODTRAN inversed LST by-1.3 (-2.5) K when the total water vapor amount is less (larger) than 20 mm. This provides useful hints for further improvement of the LST retrieval algorithms' accuracy and consistency.

  2. Modelling interannual variation in the spring and autumn land surface phenology of the European forest

    NASA Astrophysics Data System (ADS)

    Rodriguez-Galiano, Victor F.; Sanchez-Castillo, Manuel; Dash, Jadunandan; Atkinson, Peter M.; Ojeda-Zujar, Jose

    2016-06-01

    This research reveals new insights into the weather drivers of interannual variation in land surface phenology (LSP) across the entire European forest, while at the same time establishes a new conceptual framework for predictive modelling of LSP. Specifically, the random-forest (RF) method, a multivariate, spatially non-stationary and non-linear machine learning approach, was introduced for phenological modelling across very large areas and across multiple years simultaneously: the typical case for satellite-observed LSP. The RF model was fitted to the relation between LSP interannual variation and numerous climate predictor variables computed at biologically relevant rather than human-imposed temporal scales. In addition, the legacy effect of an advanced or delayed spring on autumn phenology was explored. The RF models explained 81 and 62 % of the variance in the spring and autumn LSP interannual variation, with relative errors of 10 and 20 %, respectively: a level of precision that has until now been unobtainable at the continental scale. Multivariate linear regression models explained only 36 and 25 %, respectively. It also allowed identification of the main drivers of the interannual variation in LSP through its estimation of variable importance. This research, thus, shows an alternative to the hitherto applied linear regression approaches for modelling LSP and paves the way for further scientific investigation based on machine learning methods.

  3. Modifying a dynamic global vegetation model for simulating large spatial scale land surface water balances

    NASA Astrophysics Data System (ADS)

    Tang, G.; Bartlein, P. J.

    2012-08-01

    Satellite-based data, such as vegetation type and fractional vegetation cover, are widely used in hydrologic models to prescribe the vegetation state in a study region. Dynamic global vegetation models (DGVM) simulate land surface hydrology. Incorporation of satellite-based data into a DGVM may enhance a model's ability to simulate land surface hydrology by reducing the task of model parameterization and providing distributed information on land characteristics. The objectives of this study are to (i) modify a DGVM for simulating land surface water balances; (ii) evaluate the modified model in simulating actual evapotranspiration (ET), soil moisture, and surface runoff at regional or watershed scales; and (iii) gain insight into the ability of both the original and modified model to simulate large spatial scale land surface hydrology. To achieve these objectives, we introduce the "LPJ-hydrology" (LH) model which incorporates satellite-based data into the Lund-Potsdam-Jena (LPJ) DGVM. To evaluate the model we ran LH using historical (1981-2006) climate data and satellite-based land covers at 2.5 arc-min grid cells for the conterminous US and for the entire world using coarser climate and land cover data. We evaluated the simulated ET, soil moisture, and surface runoff using a set of observed or simulated data at different spatial scales. Our results demonstrate that spatial patterns of LH-simulated annual ET and surface runoff are in accordance with previously published data for the US; LH-modeled monthly stream flow for 12 major rivers in the US was consistent with observed values respectively during the years 1981-2006 (R2 > 0.46, p < 0.01; Nash-Sutcliffe Coefficient > 0.52). The modeled mean annual discharges for 10 major rivers worldwide also agreed well (differences < 15%) with observed values for these rivers. Compared to a degree-day method for snowmelt computation, the addition of the solar radiation effect on snowmelt enabled LH to better simulate monthly

  4. Global observation-based diagnosis of soil moisture control on land surface flux partition

    NASA Astrophysics Data System (ADS)

    Gallego-Elvira, Belen; Taylor, Christopher M.; Harris, Phil P.; Ghent, Darren; Veal, Karen L.; Folwell, Sonja S.

    2016-04-01

    Soil moisture plays a central role in the partition of available energy at the land surface between sensible and latent heat flux to the atmosphere. As soils dry out, evapotranspiration becomes water-limited ("stressed"), and both land surface temperature (LST) and sensible heat flux rise as a result. This change in surface behaviour during dry spells directly affects critical processes in both the land and the atmosphere. Soil water deficits are often a precursor in heat waves, and they control where feedbacks on precipitation become significant. State-of-the-art global climate model (GCM) simulations for the Coupled Model Intercomparison Project Phase 5 (CMIP5) disagree on where and how strongly the surface energy budget is limited by soil moisture. Evaluation of GCM simulations at global scale is still a major challenge owing to the scarcity and uncertainty of observational datasets of land surface fluxes and soil moisture at the appropriate scale. Earth observation offers the potential to test how well GCM land schemes simulate hydrological controls on surface fluxes. In particular, satellite observations of LST provide indirect information about the surface energy partition at 1km resolution globally. Here, we present a potentially powerful methodology to evaluate soil moisture stress on surface fluxes within GCMs. Our diagnostic, Relative Warming Rate (RWR), is a measure of how rapidly the land warms relative to the overlying atmosphere during dry spells lasting at least 10 days. Under clear skies, this is a proxy for the change in sensible heat flux as soil dries out. We derived RWR from MODIS Terra and Aqua LST observations, meteorological re-analyses and satellite rainfall datasets. Globally we found that on average, the land warmed up during dry spells for 97% of the observed surface between 60S and 60N. For 73% of the area, the land warmed faster than the atmosphere (positive RWR), indicating water stressed conditions and increases in sensible heat flux

  5. Characterization of Land Surfaces with Satellite-borne Sensor

    NASA Astrophysics Data System (ADS)

    Qiao, Y.

    Hot groundwater is a kind of valuable natural resources to be explored utilized. Shanxi Province, located in the eastern Loess Plateau of China, is rich in geothermal resources, most of which was found in irrigation well drilling or geological survey. Basic study is weak. Now new developed Remote Sensing technique provides geothermal study with an advanced way. Air-RS information of thermal infrared and dada from thermal channel of Meteorological Landset AVHRR has been used widely. A thermal infrared channel (TM6) was installed in the U.S. second Landset, Its resolving power of space is as high as 120m, 10 times more than one of AVHRR. A Landset earth recourses launched by China and Brazil (CBERS-1) in 1999, including a spectrum of thermal infrared. It is paid a great interested and attention to survey geothermal resources using thermal infrared. This article is a brief introduction of finding hot groundwater with on the bases of differences of thermal radiation of objects reflected by thermal infrared in the Landset, and treated with HIS colors changes. This study provides an advanced way widely used to exploit hot groundwater and to promote the development of tourism and geothermal medical in China.

  6. A Coupled Land Surface-Subsurface Biogeochemical Model for Aqueous and Gaseous Nitrogen Losses

    NASA Astrophysics Data System (ADS)

    Gu, C.; Maggi, F.; Riley, W.; Pan, L.; Xu, T.; Oldenburg, C.; Miller, N.

    2008-12-01

    In recent years concern has grown over the contribution of nitrogen (N) fertilizers to nitrate (NOB3PB-P) water pollution and atmospheric pollution of nitrous oxide (NB2BO), nitric oxide (NO), and ammonia (NHB3B). Characterizing the amount and species of N losses is therefore essential in developing a strategy to estimate and mitigate N leaching and emission to the atmosphere. Indeed, transformations of nitrogen depend strongly on water content, soil temperature, and nitrogen concentration. Land surface processes therefore have to be taken into account to properly characterize N biogeochemical cycling. However, most current nitrogen biogeochemical models take the land surface as the upper boundary by lumping the complex processes above the surface as known boundary conditions. In this study, an extant subsurface mechanistic N cycle model (TOUGHREACT-N) was coupled with the community land model (CLM). The resulting coupled model extends the modeling capability of TOUGHREACT-N to include the important energy, momentum, and moisture dynamics provided by CLM. The coupled model showed a significant impact of land-surface diurnal forcing on soil temperature and moisture and on nitrogen fluxes. We also discuss field applications of the model and discuss how temporal dynamics of nitrogen fluxes are affected by land surface processes.

  7. Quantifying uncertainties in projections of climate extremes — a perturbed land surface parameter experiment

    NASA Astrophysics Data System (ADS)

    Fischer, Erich; Lawrence, David; Sanderson, Ben

    2010-05-01

    Changes in frequency, intensity and duration of climate extremes have socio-economic impacts that reach far beyond the effects of rising global mean temperatures. We explore changes in climate extremes in response to a doubling of CO2 and corresponding uncertainties using a perturbed physics ensemble. Based on NCAR CCSM 3.5 with a mixed-layer ocean, a 108 member ensemble experiment is performed by perturbing five poorly constrained land surface model parameters individually and in all possible combinations. While the ensemble range of climate sensitivity is found to be substantially smaller than in corresponding atmospheric ensembles, temperature variability changes are highly sensitive to land surface parameter changes. These variability changes have strong implications for the tails of the temperature distribution, the extreme events. Consequently uncertainties of cold and heat extremes induced by poorly constrained land surface parameters are very large. Furthermore, simple land surface parameter perturbations regionally alter the sign of the precipitation response to increased greenhouse gas concentrations. Projections of droughts and heavy rainfall events are highly sensitive to land surface parameters.

  8. [Improvement of root parameters in land surface model (LSM )and its effect on the simulated results].

    PubMed

    Cai, Kui-ye; Liu, Jing-miao; Zhang, Zheng-qiu; Liang, Hong; He, Xiao-dong

    2015-10-01

    In order to improve root parameterization in land surface model, the sub-model for root in CERES-Maize was coupled in the SSiB2 after calibrating of maize parameters in SSiB2. The effects of two improved root parameterization schemes on simulated results of land surface flux were analyzed. Results indicated that simulation accuracy of land surface flux was enhanced when the root module provided root depth only with the SSiB2 model (scheme I). Correlation coefficients between observed and simulated values of latent flux and sensible flux increased during the whole growing season, and RMSE of linear fitting decreased. Simulation accuracy of CO2 flux was also enhanced from 121 days after sowing to mature period. On the other hand, simulation accuracy of the flux was enhanced when the root module provided root depth and root length density simultaneously for the SSiB2 model (scheme II). Compared with the scheme I, the scheme II was more comprehensive, while its simulation accuracy of land surface flux decreased. The improved root parameterization in the SSiB2 model was better than the original one, which made simulated accuracy of land-atmospheric flux improved. The scheme II overestimated root relative growth in the surface layer soil, so its simulated accuracy was lower than that of the scheme I. PMID:26995920

  9. SGP Cloud and Land Surface Interaction Campaign (CLASIC): Science and Implementation Plan

    SciTech Connect

    MA Miller; R Avissar; LK Berg; SA Edgerton; ML Fischer; T Jackson; B.Kustas; PJ Lamb; GM McFarquhar; Q Min; B Schmid; MS Torn; DD Turner

    2007-06-30

    The Cloud and Land Surface Interaction Campaign is a field experiment designed to collect a comprehensive data set that can be used to quantify the interactions that occur between the atmosphere, biosphere, land surface, and subsurface. A particular focus will be on how these interactions modulate the abundance and characteristics of small and medium size cumuliform clouds that are generated by local convection. These interactions are not well understood and are responsible for large uncertainties in global climate models, which are used to forecast future climate states. The campaign will be conducted from June 8 to June 30, 2007, at the U.S. Department of Energy’s Atmospheric Radiation Measurement Climate Research Facility Southern Great Plains site. Data will be collected using eight aircraft equipped with a variety of specialized sensors, four specially instrumented surface sites, and two prototype surface radar systems. The architecture of Cloud and Land Surface Interaction Campaign includes a high-altitude surveillance aircraft and enhanced vertical thermodynamic and wind profile measurements that will characterize the synoptic scale structure of the clouds and the land surface within the Atmospheric Radiation Measurement Climate Research Facility Southern Great Plains site. Mesoscale and microscale structures will be sampled with a variety of aircraft, surface, and radar observations.

  10. Land use change exacerbates tropical South American drought by sea surface temperature variability

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Eun; Lintner, Benjamin R.; Boyce, C. Kevin; Lawrence, Peter J.

    2011-10-01

    Observations of tropical South American precipitation over the last three decades indicate an increasing rainfall trend to the north and a decreasing trend to the south. Given that tropical South America has experienced significant land use change over the same period, it is of interest to assess the extent to which changing land use may have contributed to the precipitation trends. Simulations of the National Center for Atmospheric Research Community Atmosphere Model (NCAR CAM3) analyzed here suggest a non-negligible impact of land use on this precipitation behavior. While forcing the model by imposed historical sea surface temperatures (SSTs) alone produces a plausible north-south precipitation dipole over South America, NCAR CAM substantially underestimates the magnitude of the observed southern decrease in rainfall unless forcing associated with human-induced land use change is included. The impact of land use change on simulated precipitation occurs primarily during the local dry season and in regions of relatively low annual-mean rainfall, as the incidence of very low monthly-mean accumulations (<10 mm/month) increases significantly when land use change is imposed. Land use change also contributes to the simulated temperature increase by shifting the surface turbulent flux partitioning to favor sensible over latent heating. Moving forward, continuing pressure from deforestation in tropical South America will likely increase the occurrence of significant drought beyond what would be expected by anthropogenic warming alone and in turn compound biodiversity decline from habitat loss and fragmentation.

  11. A statistical assessment of the impact of land uses on surface water quality indexes.

    PubMed

    Seeboonruang, Uma

    2012-06-30

    The release of wastewater from various land uses is threatening the quality of surface water. Different land uses pose varying degrees of danger to water resources. The hazardous extent of each activity depends on the amount and characteristics of the wastewater. The concept of the contamination potential index (CPI) of an activity is introduced and applied here. The index depends on the quantity of wastewater from a single source and on various chemicals in the waste whose concentrations are above allowable standards. The CPI concept and the land use impact assessment are applied to the surface water conditions in Nakhon Nayok Province in the central region of Thailand. The land uses considered in this study are residential area, industrial zone, in-season and off-season rice farming, and swine and poultry livestock. Multiple linear regression analysis determines the impact of the CPIs of these land uses on certain water quality characteristics, i.e., total dissolved solids, electrical conductivity, phosphate, and chloride concentrations, using CPIs and previous water quality measurements. The models are further verified according to the current CPIs and measured concentrations. The results of the backward and forward modeling show that the land uses that affect water quality are off-season rice farming, raising poultry, and residential activity. They demonstrate that total dissolved solids and conductivity are reasonable parameters to apply in the land use assessment.

  12. Improving weather predictability by including land-surface model parameter uncertainty

    NASA Astrophysics Data System (ADS)

    Orth, Rene; Dutra, Emanuel; Pappenberger, Florian

    2016-04-01

    The land surface forms an important component of Earth system models and interacts nonlinearly with other parts such as ocean and atmosphere. To capture the complex and heterogenous hydrology of the land surface, land surface models include a large number of parameters impacting the coupling to other components of the Earth system model. Focusing on ECMWF's land-surface model HTESSEL we present in this study a comprehensive parameter sensitivity evaluation using multiple observational datasets in Europe. We select 6 poorly constrained effective parameters (surface runoff effective depth, skin conductivity, minimum stomatal resistance, maximum interception, soil moisture stress function shape, total soil depth) and explore their sensitivity to model outputs such as soil moisture, evapotranspiration and runoff using uncoupled simulations and coupled seasonal forecasts. Additionally we investigate the possibility to construct ensembles from the multiple land surface parameters. In the uncoupled runs we find that minimum stomatal resistance and total soil depth have the most influence on model performance. Forecast skill scores are moreover sensitive to the same parameters as HTESSEL performance in the uncoupled analysis. We demonstrate the robustness of our findings by comparing multiple best performing parameter sets and multiple randomly chosen parameter sets. We find better temperature and precipitation forecast skill with the best-performing parameter perturbations demonstrating representativeness of model performance across uncoupled (and hence less computationally demanding) and coupled settings. Finally, we construct ensemble forecasts from ensemble members derived with different best-performing parameterizations of HTESSEL. This incorporation of parameter uncertainty in the ensemble generation yields an increase in forecast skill, even beyond the skill of the default system. Orth, R., E. Dutra, and F. Pappenberger, 2016: Improving weather predictability by

  13. Using land-cover change as dynamic variables in surface-water and water-quality models

    USGS Publications Warehouse

    Karstensen, Krista A.; Warner, Kelly L.; Kuhn, Anne

    2010-01-01

    Land-cover data are typically used in hydrologic modeling to establish or describe land surface dynamics. This project is designed to demonstrate the use of land-cover change data in surface-water and water-quality models by incorporating land-cover as a variable condition. The project incorporates three different scenarios that vary hydrologically and geographically: 1) Agriculture in the Plains, 2) Loon habitat in New England, and 3) Forestry in the Ozarks.

  14. EDITORIAL: Focus on Advances in Surface and Interface Science 2008 FOCUS ON ADVANCES IN SURFACE AND INTERFACE SCIENCE 2008

    NASA Astrophysics Data System (ADS)

    Scheffler, Matthias; Schneider, Wolf-Dieter

    2008-12-01

    Basic research in surface and interface science is highly interdisciplinary, covering the fields of physics, chemistry, biophysics, geo-, atmospheric and environmental sciences, material science, chemical engineering, and more. The various phenomena are interesting by themselves, and they are most important in nearly all modern technologies, as for example electronic, magnetic, and optical devices, sensors, catalysts, lubricants, hard and thermal-barrier coatings, protection against corrosion and crack formation under harsh environments. In fact, detailed understanding of the elementary processes at surfaces is necessary to support and to advance the high technology that very much founds the prosperity and lifestyle of our society. Current state-of-the-art experimental studies of elementary processes at surfaces, of surface properties and functions employ a variety of sophisticated tools. Some are capable of revealing the location and motion of individual atoms. Others measure excitations (electronic, magnetic and vibronic), employing, for example, special light sources such as synchrotrons, high magnetic fields, or free electron lasers. The surprising variety of intriguing physical phenomena at surfaces, interfaces, and nanostructures also pose a persistent challenge for the development of theoretical descriptions, methods, and even basic physical concepts. This second focus issue on the topic of 'Advances in Surface and Interface Science' in New Journal of Physics, following on from last year's successful collection, provides an exciting synoptic view on the latest pertinent developments in the field. Focus on Advances in Surface and Interface Science 2008 Contents Organic layers at metal/electrolyte interfaces: molecular structure and reactivity of viologen monolayers Stephan Breuer, Duc T Pham, Sascha Huemann, Knud Gentz, Caroline Zoerlein, Ralf Hunger, Klaus Wandelt and Peter Broekmann Spin polarized d surface resonance state of fcc Co/Cu(001) K Miyamoto, K

  15. Effect of land cover and green space on land surface temperature of a fast growing economic region in Malaysia

    NASA Astrophysics Data System (ADS)

    Sheikhi, A.; Kanniah, K. D.; Ho, C. H.

    2015-10-01

    Green space must be increased in the development of new cities as green space can moderate temperature in the cities. In this study we estimated the land surface temperature (LST) and established relationships between LST and land cover and various vegetation and urban surface indices in the Iskandar Malaysia (IM) region. IM is one of the emerging economic gateways of Malaysia, and is envisaged to transform into a metropolis by 2025. This change may cause increased temperature in IM and therefore we conducted a study by using Landsat 5 image covering the study region (2,217 km2) to estimate LST, classify different land covers and calculate spectral indices. Results show that urban surface had highest LST (24.49 °C) and the lowest temperature was recorded in, forest, rubber and water bodies ( 20.69 to 21.02°C). Oil palm plantations showed intermediate mean LST values with 21.65 °C. We further investigated the relationship between vegetation and build up densities with temperature. We extracted 1000 collocated pure pixels of Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), Normalized Difference Built-up Index (NDBI), Urban Index (UI) and LST in the study area. Results show a strong and significant negative correlation with (R2= -0.74 and -0.79) respectively between NDVI, NDWI and LST . Meanwhile a strong positive correlation (R2=0.8 and 0.86) exists between NDBI, UI and LST. These results show the importance of increasing green cover in urban environment to combat any adverse effects of climate change.

  16. Pathway of radioisotopes from land surface to sewage sludge

    NASA Astrophysics Data System (ADS)

    Fischer, Helmut W.; Yokoo, Yoshiyuki

    2014-05-01

    Radioactive surface contaminations will only partially remain at the original location - a fraction of the inventory will take part in (mainly terrestrial and aquatic) environmental transport processes. The probably best known and most important process comprises the food chain. Besides, the translocation of dissolved and particle-bound radioisotopes with surface waters plays an important role. These processes can have the effect of displacing large radioisotope amounts over considerable distances and of creating new sinks and hot spots, as it is already known for sewage sludge. We are reporting on a combined modeling and experimental project concerning the transport of I-131 and Cs-134/Cs-137 FDNPP 2011 depositions in the Fukushima Prefecture. Well-documented experimental data sets are available for surface deposition and sewage sludge concentrations. The goal is to model the pathway in between, involving surface runoff, transport in the sewer system and processes in the sewage treatment plant. Watershed runoff and sewer transport will be treated with models developed recently by us in other projects. For sewage treatment processes a new model is currently being constructed. For comparison and further validation, historical data from Chernobyl depositions and tracer data from natural and artificial, e.g. medical, isotopes will be used. First results for 2011 data from Fukushima Prefecture will be presented. The benefits of the study are expected to be two-fold: on one hand, the abundant recent and historical data will help to develop and improve environmental transport models; on the other hand, both data and models will help in identifying the most critical points in the envisaged transport pathways in terms of radiation protection and waste management.

  17. Use of a discrimination rule for predicting a successful spacecraft landing on the surface of a celestial body

    NASA Astrophysics Data System (ADS)

    Buslaev, S. P.

    2013-12-01

    An estimate for the probability of a successful spacecraft landing în the complex relief of a celestial body given random initial landing conditions is considered. The estimation is performed according to values of these initial conditions, including landing orientation, the linear and angular velocity of the lander, as well as surface relief and behavior of the ground at the landing site. For a trial sample involving random landing situations, the equations of motion of the lander are solved, from which the discrimination rule is derived. Then a successful landing is predicted by means of the rule without the solution of the equations of motion during landing.

  18. GRASP Algorithm: retrieval of the aerosol properties over land surface from satellite observations (solicited)

    NASA Astrophysics Data System (ADS)

    Dubovik, Oleg; Litvinov, Pavel; Lapyonok, Tatyana; Ducos, Fabrice; Aspetsberger, Michael; Planer, Wolfgang; Federspiel, Christian; Fuertes, David

    The GRASP (Generalized Retrieval of Aerosol and Surface Properties) algorithm has been developed for enhanced characterization of the properties of both aerosol and land surface from diverse remote sensing observations. The concept of the algorithm is described in details by Dubovik et al. (2011). The algorithm is based on highly advanced statistically optimized fitting implemented as Multi-Term Least Square minimization (Dubovik, 2004) and deduces nearly 50 unknowns for each observed site. The algorithm derives a set of aerosol parameters similar to that derived by AERONET including detailed particle size distribution, the spectral dependence on the complex index of refraction and the fraction of non-spherical particles. The algorithm uses detailed aerosol and surface models and fully accounts for all multiple interactions of scattered solar light with aerosol, gases and the underlying surface. All calculations are done on-line without using traditional look-up tables. In addition, the algorithm can use the new multi-pixel concept - a simultaneous fitting of a large group of pixels with additional constraints limiting the time variability of surface properties and spatial variability of aerosol properties. This principle provides a possibility to improve retrieval for multiple observations even if the observations are not exactly co-incident or co-located. Significant efforts have been spent for optimization and speedup of the GRASP computer routine and retrievals from satellite observations. For example, the routine has been adapted for running at GPGPUs accelerators. Originally GRASP has been developed for POLDER/PARASOL multi-viewing imager and later adapted to a number of other satellite sensors such as MERIS at polar-orbiting platform and COCI/GOMS geostationary observations. The results of numerical tests and results of applications to real data will be presented. REFERENCES: Dubovik, et al.,“Statistically optimized inversion algorithm for enhanced

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    Radiance assimilation (RA) has been used in operational numerical weather forecasting for generating realistic initial and boundary conditions for the last two decades. Previous studies have shown that the same approach can be used to characterize seasonal snow. Since the penetration depth of microwaves depends essentially on snow physical properties, studies have also shown that for RA to be successful, it is crucial that the land surface model (LSM) represents with great fidelity snow physical properties such as the effective grain size, the temperature, the stratigraphy, the densification and the melt/refreeze processes. The Community Land Model version 4 (CLM4), the land model component of the Community Earth System Model (CESM), describes the physical, chemical, biological, and hydrological processes by which terrestrial ecosystems interact with climate across a variety of spatial and temporal scales. Sub-grid heterogeneity of the CLM4 is represented by fractional coverage of glacier, lake, wetland, urban, and vegetation land cover types. The vegetation portion is further divided into mosaic of plant functional types (pfts) each with its own leaf and stem area index and canopy height. Processes such as snow accumulation, depletion, densification, metamorphism, percolation, and refreezing of water are represented by a state-of-the-art multi-layer (up to five layers) snow model. Each snow layer is characterized by its thickness, ice mass, liquid water content, temperature, and effective grain radius. The model is considered to be one of the most sophisticated snow models ever within a general circulation model. One of the main challenges in simulating the radiance observed by a radiometer on-board a satellite is the spatial heterogeneity of the land within the footprint of the radiometer. Since CLM4 has the capability to represent the sub-grid heterogeneity, it is perfect candidate for a model operator for simulating the observed brightness temperature (Tb). The

  20. 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.

  1. Soft-Landing of Peptide IOns Onto Self-Assembled Monolayer Surfaces: an Overview

    SciTech Connect

    Laskin, Julia; Wang, Peng; Hadjar, Omar

    2008-02-28

    This review is focused on what has been learned in recent research studies concerned with fundamental aspects of soft-landing and reactive landing of peptide ions on self-assembled monolayer surfaces (SAMs). Peptide ions are particularly attractive model systems that provide important insights on the behavior of soft landed proteins, while SAMs provide a convenient and flexible platform for tailoring the interfacial properties of metals and semiconductor surfaces. Deposition of mass-selected ions on surfaces is accompanied by a number of processes including charge reduction, neutralization, covalent and non-covalent binding, and thermal desorption of ions and molecules from the substrate. Factors that affect the competition between these processes are discussed.

  2. [A Novel Method of Soil Moisture Content Monitoring by Land Surface Temperature and LAI].

    PubMed

    Gao, Zhong-ling; Zheng, Xiao-po; Sun, Yue-jun; Wang, Jian-hua

    2015-11-01

    Land surface temperature (Ts) is influenced by soil background and vegetation growing conditions, and the combination of Ts and vegetation indices (Vis) can indicate the status of surface soil moisture content (SMC). In this study, Advanced Temperature Vegetation Dryness Index (ATVDI) used for monitoring SMC was proposed on the basis of the simulation results with agricultural climate model CUPID. Previous studies have concluded that Normalized Difference Vegetation Index (NDVI) easily reaches the saturation point, andLeaf Area Index (LAI) was then used instead of NDVI to estimate soil moisture content in the paper. With LAI-Ts scatter diagram established by the simulation results of CUPID model; how Ts varied with LAI and SMC was found. In the case of the identical soil background, the logarithmic relations between Ts and LAI were more accurate than the linear relations included in Temperature Vegetation Dryness Index (TVDI), based on which ATVDI was then developed. LAI-Ts scatter diagram with satellite imagery were necessary for determining the expression of the upper and lower logarithmic curves while ATVDI was used for monitoring SMC. Ts derived from satellite imagery were then transformed to the Ts-value which has the same SMC and the minimum LAI in study area with look-up table. The measured SMC from the field sites in Weihe Plain, Shanxi Province, China, and the products of LAI and Ts (MOD15A2 and MOD11A2, respectively) produced by the image derived from Moderate Resolution Imaging Spectrometer (MODIS) were collected to validate the new method proposed in this study. The validation results shown that ATVDI (R² = 0.62) was accurate enough to monitor SMC, and it achieved better result than TVDI. Moreover, ATVDI-derived result were Ts values with some physical meanings, which made it comparative in different periods. Therefore, ATVDI is a promising method for monitoring SMC in different time-spatial scales in agricultural fields. PMID:26978922

  3. Toward Improved Land Surface Initialization in Support of Regional WRF Forecasts at the Kenya Meteorological Department

    NASA Technical Reports Server (NTRS)

    Case. Jonathan; 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 Department (KMD). 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 boundary layer 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 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 numerical weather prediction models. Enhanced regional modeling capabilities have the potential to improve forecast guidance in support of daily operations and high-end events over east Africa. KMD currently runs a configuration of the Weather Research and Forecasting (WRF) model in real time to support its daily forecasting operations, invoking the Nonhydrostatic Mesoscale Model (NMM) dynamical core. They make use of the National Oceanic and Atmospheric Administration / National Weather Service Science and Training Resource Center's Environmental Modeling System (EMS) to manage and produce the WRF-NMM model runs on a 7-km regional grid over eastern Africa. Two organizations at the National Aeronautics and Space Administration Marshall Space Flight Center in Huntsville, AL, SERVIR and the Short-term Prediction Research and Transition (SPoRT) Center, have established a working partnership with KMD for enhancing its regional modeling capabilities. To accomplish this goal, SPoRT and SERVIR will provide experimental land surface initialization datasets and model verification capabilities to KMD. To produce a land-surface initialization more consistent with the resolution of the KMD-WRF runs, the NASA Land Information System (LIS

  4. Classification of satellite time series-derived land surface phenology focused on the northern Fertile Crescent

    NASA Astrophysics Data System (ADS)

    Bunker, Brian

    Land surface phenology describes events in a seasonal vegetation cycle and can be used in a variety of applications from predicting onset of future drought conditions, to revealing potential limits of historical dry farming, to guiding more accurate dating of archeological sites. Traditional methods of monitoring vegetation phenology use data collected in situ. However, vegetation health indices derived from satellite remote sensor data, such as the normalized difference vegetation index (NDVI), have been used as proxy for vegetation phenology due to their repeated acquisition and broad area coverage. Land surface phenology is accessible in the NDVI satellite record when images are processed to be intercomparable over time and temporally ordered to create a time series. This study utilized NDVI time series to classify areas of similar vegetation phenology in the northern Fertile Crescent, an area from the middle Mediterranean coast to southern/south-eastern Turkey to western Iran and northern Iraq. Phenological monitoring of the northern Fertile Crescent is critical due to the area's minimal water resources, susceptibility to drought, and understanding ancient historical reliance on precipitation for subsistence dry farming. Delineation of phenological classes provides areal and temporal synopsis of vegetation productivity time series. Phenological classes were developed from NDVI time series calculated from NOAA's Advanced Very High Resolution Radiometer (AVHRR) imagery with 8 × 8 km spatial resolution over twenty-five years, and by NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) with 250 × 250 m spatial resolution over twelve years. Both AVHRR and MODIS time series were subjected to data reduction techniques in spatial and temporal dimensions. Optimized ISODATA clusters were developed for both of these data reduction techniques in order to compare the effects of spatial versus temporal aggregation. Within the northern Fertile Crescent study area

  5. A Real-Time MODIS Vegetation Composite for Land Surface Models and Short-Term Forecasting

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; LaFontaine, Frank J.; Kumar, Sujay V.; Jedlovec, Gary J.

    2011-01-01

    The NASA Short-term Prediction Research and Transition (SPoRT) Center is producing real-time, 1- km resolution Normalized Difference Vegetation Index (NDVI) gridded composites over a Continental U.S. domain. These composites are updated daily based on swath data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the polar orbiting NASA Aqua and Terra satellites, with a product time lag of about one day. A simple time-weighting algorithm is applied to the NDVI swath data that queries the previous 20 days of data to ensure a continuous grid of data populated at all pixels. The daily composites exhibited good continuity both spatially and temporally during June and July 2010. The composites also nicely depicted high greenness anomalies that resulted from significant rainfall over southwestern Texas, Mexico, and New Mexico during July due to early-season tropical cyclone activity. The SPoRT Center is in the process of computing greenness vegetation fraction (GVF) composites from the MODIS NDVI data at the same spatial and temporal resolution for use in the NASA Land Information System (LIS). The new daily GVF dataset would replace the monthly climatological GVF database (based on Advanced Very High Resolution Radiometer [AVHRR] observations from 1992-93) currently available to the Noah land surface model (LSM) in both LIS and the public version of the Weather Research and Forecasting (WRF) model. The much higher spatial resolution (1 km versus 0.15 degree) and daily updates based on real-time satellite observations have the capability to greatly improve the simulation of the surface energy budget in the Noah LSM within LIS and WRF. Once code is developed in LIS to incorporate the daily updated GVFs, the SPoRT Center will conduct simulation sensitivity experiments to quantify the impacts and improvements realized by the MODIS real-time GVF data. This presentation will describe the methodology used to develop the 1-km MODIS NDVI composites and

  6. Influences of specific land use/land cover conversions on climatological normals of near-surface temperature

    USGS Publications Warehouse

    Hale, Robert C.; Gallo, Kevin P.; Loveland, Thomas R.

    2008-01-01

    Quantification of the effects of land use/land cover (LULC) changes on proximal measurements of near-surface air temperature is crucial to a better understanding of natural and anthropogenically induced climate change. In this study, data from stations utilized in deriving U.S. climatological temperature normals were analyzed in conjunction with NCEP-NCAR 50-Year Reanalysis (NNR) estimates and highly accurate LULC change maps in order to isolate the effects of LULC change from other climatological factors. While the “Normals” temperatures exhibited considerable warming in both minima and maxima, the NNR data revealed that the majority of the warming of maximum temperatures was not due to nearby LULC change. Warming of minimum temperatures was roughly evenly split between the effects of LULC change and other influences. Furthermore, the effects of LULC change varied considerably depending upon the particular type of land cover conversion that occurred. Urbanization, in particular, was found to result in warming of minima and maxima, while some LULC conversions that might be expected to have significantly altered nearby temperatures (e.g., clear-cutting of forests) did not.

  7. [An operational remote sensing algorithm of land surface evapotranspiration based on NOAA PAL dataset].

    PubMed

    Hou, Ying-Yu; He, Yan-Bo; Wang, Jian-Lin; Tian, Guo-Liang

    2009-10-01

    Based on the time series 10-day composite NOAA Pathfinder AVHRR Land (PAL) dataset (8 km x 8 km), and by using land surface energy balance equation and "VI-Ts" (vegetation index-land surface temperature) method, a new algorithm of land surface evapotranspiration (ET) was constructed. This new algorithm did not need the support from meteorological observation data, and all of its parameters and variables were directly inversed or derived from remote sensing data. A widely accepted ET model of remote sensing, i. e., SEBS model, was chosen to validate the new algorithm. The validation test showed that both the ET and its seasonal variation trend estimated by SEBS model and our new algorithm accorded well, suggesting that the ET estimated from the new algorithm was reliable, being able to reflect the actual land surface ET. The new ET algorithm of remote sensing was practical and operational, which offered a new approach to study the spatiotemporal variation of ET in continental scale and global scale based on the long-term time series satellite remote sensing images.

  8. Impact of land-surface initialization on sub-seasonal to seasonal forecasts over Europe

    NASA Astrophysics Data System (ADS)

    Prodhomme, Chloé; Doblas-Reyes, Francisco; Bellprat, Omar; Dutra, Emanuel

    2016-08-01

    Land surfaces and soil conditions are key sources of climate predictability at the seasonal time scale. In order to estimate how the initialization of the land surface affects the predictability at seasonal time scale, we run two sets of seasonal hindcasts with the general circulation model EC-Earth2.3. The initialization of those hindcasts is done either with climatological or realistic land initialization in May using the ERA-Land re-analysis. Results show significant improvements in the initialized run occurring up to the last forecast month. The prediction of near-surface summer temperatures and precipitation at the global scale and over Europe are improved, as well as the warm extremes prediction. As an illustration, we show that the 2010 Russian heat wave is only predicted when soil moisture is initialized. No significant improvement is found for the retrospective prediction of the 2003 European heat wave, suggesting this event to be mainly large-scale driven. Thus, we confirm that late-spring soil moisture conditions can be decisive in triggering high-impact events in the following summer in Europe. Accordingly, accurate land-surface initial conditions are essential for seasonal predictions.

  9. [An operational remote sensing algorithm of land surface evapotranspiration based on NOAA PAL dataset].

    PubMed

    Hou, Ying-Yu; He, Yan-Bo; Wang, Jian-Lin; Tian, Guo-Liang

    2009-10-01

    Based on the time series 10-day composite NOAA Pathfinder AVHRR Land (PAL) dataset (8 km x 8 km), and by using land surface energy balance equation and "VI-Ts" (vegetation index-land surface temperature) method, a new algorithm of land surface evapotranspiration (ET) was constructed. This new algorithm did not need the support from meteorological observation data, and all of its parameters and variables were directly inversed or derived from remote sensing data. A widely accepted ET model of remote sensing, i. e., SEBS model, was chosen to validate the new algorithm. The validation test showed that both the ET and its seasonal variation trend estimated by SEBS model and our new algorithm accorded well, suggesting that the ET estimated from the new algorithm was reliable, being able to reflect the actual land surface ET. The new ET algorithm of remote sensing was practical and operational, which offered a new approach to study the spatiotemporal variation of ET in continental scale and global scale based on the long-term time series satellite remote sensing images. PMID:20077694

  10. Land surface temperature measurements for EOS MODIS data

    NASA Technical Reports Server (NTRS)

    Wan, Zhengming

    1994-01-01

    Work accomplished includes: Beta delivery 1 of the MODIS LST product; the first version of MODIS LST ATBD; update of the atmospheric radiative transfer code ATRAD; the development of a new approach look-up table method; and improvement of the TIR spectrometer. Preliminary feasibility analysis of the look-up table approach is presented in terms of showing the effects on the TIR radiance at the top of the atmosphere of the stratospheric and upper atmospheric temperature profiles, the surface emissivity and temperature, the lower atmospheric temperature and water vapor profiles, and the viewing angle.

  11. Parameterization of aerodynamic roughness of China's land surface vegetation from remote sensing data

    NASA Astrophysics Data System (ADS)

    Hu, Deyong; Xing, Liwei; Huang, Shengli; Deng, Lei; Xu, Yingjun

    2014-01-01

    Aerodynamic roughness length (z0) is one of the important parameters that influence energy exchange at the land-atmosphere interface in numerical models, so it is of significance to accurately parameterize the land surface. To parameterize the z0 values of China's land surface vegetation using remote sensing data, we parameterized the vegetation canopy area index using the leaf area index and land cover products of moderate resolution imaging spectroradiometer data. Then we mapped the z0 values of different land cover types based on canopy area index and vegetation canopy height data. Finally, we analyzed the intra-annual monthly z0 values. The conclusions are: (1) This approach has been developed to parameterize large scale regional z0 values from multisource remote sensing data, allowing one to better model the land-atmosphere flux exchange based on this feasible and operational scheme. (2) The variation of z0 values in the parametric model is affected by the vegetation canopy area index and its threshold had been calculated to quantify different vegetation types. In general, the z0 value will increase during the growing season. When the threshold in the dense vegetation area or in the growing season is exceeded, the z0 values will decrease but the zero-plane displacement heights will increase. This technical scheme to parameterize the z0 can be applied to large-scale regions at a spatial resolution of 1 km, and the dynamic products of z0 can be used in high resolution land or atmospheric models to provide a useful scheme for land surface parameterization.

  12. The cumulative effects of urban expansion on land surface temperatures in metropolitan JingjinTang, China

    NASA Astrophysics Data System (ADS)

    Hu, Yonghong; Jia, Gensuo; Hou, Meiting; Zhang, Xiaoxuan; Zheng, Feixiang; Liu, Yonghe

    2015-10-01

    Rapid urbanization has resulted in the permanent conversion of large areas of cropland and natural vegetation to impervious surfaces and therefore greatly modified land surface properties and land-atmosphere interactions. This study sought to examine the urbanization process using Landsat images from 2001 to 2010 in metropolitan JingjinTang (JJT), a rapidly expanding urban cluster in northern China. We aggregated the original results of land use data as fractional cover information in 1 km and 10 km grids. Annual and seasonal land surface temperatures (LSTs) were processed from Moderate Resolution Imaging Spectroradiometer products. We used moving window and gradient analysis methods to examine the differences in LST between urban and other land types, further identifying LST increases in gradients of urbanization levels. Urban extent increased by 1.6 times, and approximately 45% newly developed areas were converted from croplands during this process. Emerging urban land in JJT has caused approximately 0.85 ± 0.68°C warming in terms of annual mean LST, and the greatest warming occurred in the summer. An increase in urban land of 10% in a 1 km grid in JJT would cause approximately a 0.21°C increase in annual LST. Urbanization also led to increases in daytime LSTs and nighttime LSTs by approximately 1.03 ± 1.38°C and 0.78 ± 1.02°C, respectively. The warming trend induced by urbanization exhibits clear seasonal and diurnal differences, and this warming trend is most likely caused by the cumulative effects of changes in land properties, radiation storage, and anthropogenic heat release by urbanization.

  13. Dependence of the convective precipitation forecasts from details of the land-surface model

    NASA Astrophysics Data System (ADS)

    Jakubiak, Bogumil; Hodur, Richard; Herman-Izycki, Leszek; Sierzega, Mikolaj

    2010-05-01

    ICM is testing few land-surface sub-models coupled into mesoscale numerical prediction models running quasi-operationally at the University of Warsaw. In the research version of the mesoscale NWP model COAMPS the land-surface model NOAH is implemented, in UKMO Unified Model some versions of MOSES schemes are tested. Results of precipitation forecasts obtained from different sets of land-surface parameters are compared to our operational versions of both models. Validation of the model results was performed using object oriented approach - contiguous rain area (CRA) method. CRA is defined as a region bounded by selected rain rate contour in the forecast and in the observations. The location error is determined using the pattern matching technique. The forecast field is horizontally translated over the observed field until the best match is obtained. The location error is then simply the vector displacement of the forecast. All precipitation forecasts were verified against radar observations collected from radars operated in the area of Baltic Sea catchment. Primary radar observations used in our study consist of 15 minutes reflectivity data on 500 m CAPPI level. These data are integrated into 1h and 15 minutes precipitation accumulations using standard Z-R relationship. Land-surface models have large number of parameters. For example, the NOAH LSM has 33 parameters: 10 related to the vegetation, and 23 that describe soil properties. The main purpose of this study was to evaluate the changes in precipitation patters as a function of the land-surface scheme used and the preferred values of main parameters of the scheme. The impact of the features of land-surface models on the quality of the convective precipitation forecasts has been tested on selected cases.

  14. Observations of albedo and radiation balance over postforest land surfaces in the eastern Amazon Basin

    SciTech Connect

    Giambelluca, T.W.; Nullet, M.A.; Ziegler, A.D.

    1997-05-01

    Regional climatic change, including significant reductions in Amazon Basin evaporation and precipitation, has been predicted by numerical simulations of total tropical forest removal. These results have been shown to be very sensitive to the prescription of the albedo shift associated with conversion from forest to a replacement land cover. Modelers have so far chosen to use an {open_quotes}impoverished grassland{close_quotes} scenario to represent the postforest land surface. This choice maximizes the shifts in land surface parameters, especially albedo (fraction of incident shortwave radiation reflected by the surface). Recent surveys show secondary vegetation to be the dominant land cover for some deforested areas of the Amazon. This paper presents the results of field measurements of radiation flux over various deforested surfaces on a small farm in the eastern Amazonian state of Para. The albedo of fields in active use was as high as 0.176, slightly less than the 0.180 recently determined for Amazonian pasture and substantially less than the 0.19 commonly used in GCM simulations of deforestation. For 10-yr-old secondary vegetation, albedo was 0.135, practically indistinguishable from the recently published mean primary forest albedo of 0.134. Measurements of surface temperature and net radiation show that, despite similarity in albedo, secondary vegetation differs from primary forest in energy and mass exchange. The elevation of midday surface temperature above air temperature was found to be greatest for actively and recently farmed land, declining with time since abandonment. Net radiation was correspondingly lower for fields in active or recent use. Using land cover analyses of the region surrounding the study area for 1984, 1988, and 1991, the pace of change in regional-mean albedo is estimated to have declined and appears to be leveling at a value less than 0.03 above that of the original forest cover. 41 refs., 3 figs., 8 tabs.

  15. The impact of quantified land surface uncertainties on seasonal forecast skill

    NASA Astrophysics Data System (ADS)

    MacLeod, D.

    2015-12-01

    The land surface is a key component in seasonal forecasting, and well-represented soil moisture is particularly important for the simulation of heatwaves. Methods to represent uncertainties in the atmosphere of climate models have been shown to improve forecasts. However these methods have not yet been applied to the land surface component of climate models. We consider three methods of incorporating uncertainties into CHTESSEL, the land surface model of the ECMWF forecasting system. These methods are: stochastic perturbation of soil moisture tendencies, static and then stochastic perturbation of key soil parameters. We present analysis of the results of fully coupled seasonal hindcasts with each method applied. We find significant improvement for extreme events, particularly in terms of forecast reliability of upper and lower quintile soil moisture. These improvements also propagate into the atmosphere, impacting the reliability of seasonal-average predictions of latent and sensible heat flux anomalies and air temperature. This improvement is consistent over the hindcast, and also for particular cases such as the 2003 European summer (MacLeod et al 2015). We also present work with an uncoupled version of CHTESSEL. Extending the method of Wood & Lettenmaier (2008), we quantify the global evolution over forecast lead-time of the relative magnitudes of initial condition, forcing and parameter uncertainty in the land surface. Among other things this gives some indication of where predictability from initial conditions is more persistent, and where uncertainty in land surface parameters has the largest impact on simulated soil moisture. MacLeod DA, CLoke, HL, Pappenberger F and Weisheimer AF (2015), Improved seasonal prediction of the hot summer of 2003 through better representation of uncertainty in the land surface, QJRMSWood, AW, and Lettenmaier DP (2008), An ensemble approach for attribution of hydrologic prediction uncertainty, GRL

  16. 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.

  17. AccuCLASS - an Enhancement of the Canadian Land Surface Scheme for Climate Assessment Over the Prairies

    NASA Astrophysics Data System (ADS)

    Loukili, Y.; Woodbury, A. D.; Snelgrove, K. R.

    2006-12-01

    The Canadian Land Surface Scheme (CLASS) is a numerical model developed at the Canadian Atmospheric Environment Service by Verseghy et al. [1991, 1993, 2000] and used to evaluate the vertical transfer of energy and water between the land surface and three soil layers. Among the features of CLASS its treatment of the land surface as a composite of four primary subareas: canopy and snow covered ground, snow-covered ground, canopy covered soil, and bare soil. The vegetation properties are also related via weighted averages to four types: needleaf trees, broadleaf trees, grass and crops. The incorporation of meteorological data as forcing inputs drives the model through advanced formulae describing the earth surface physics. These include canopy radiation and evapotranspiration, sensible and latent heat fluxes, rainfall interception, infiltration and ponding, snow melt and soil freezing. Such treatment allows for a realistic estimation of the surface energy balance. In this work, a major revision of CLASS, called AccuCLASS, is introduced, which permits a user specified depth and as many soil layers as needed. Almost all the physically based calculations of heat and moisture transfer in CLASS are kept and adequately extended to fit the desired refined mesh. In the resolution of soil temperature and heat flux terms, the GMRES iterative method replaced the explicit algebraic manipulation. Moreover, in the moisture regime, a water table lower boundary condition is added for the future coupling with groundwater models. The results of AccuCLASS are extensively validated for some synthetic runs under real-like seasonal weather conditions and different soil types, through inter-comparing to simulation outputs from SHAW [Flerchinger and Saxon, 1989], HYDRUS-1D [Simunek et al., 1998] and HELP [Schroeder et al., 1994] models. We find that AccuCLASS and SHAW accurately predict moisture and bottom drainage amounts; and that the original CLASS code does not have sufficient grid

  18. Surface Properties and Characteristics of Mars Landing Sites from Remote Sensing Data and Ground Truth

    NASA Astrophysics Data System (ADS)

    Golombek, M. P.; Haldemann, A. F.; Simpson, R. A.; Furgason, R. L.; Putzig, N. E.; Huertas, A.; Arvidson, R. E.; Heet, T.; Bell, J. F.; Mellon, M. T.; McEwen, A. S.

    2008-12-01

    Surface characteristics at the six sites where spacecraft have successfully landed on Mars can be related favorably to their signatures in remotely sensed data from orbit and from the Earth. Comparisons of the rock abundance, types and coverage of soils (and their physical properties), thermal inertia, albedo, and topographic slope all agree with orbital remote sensing estimates and show that the materials at the landing sites can be used as ground truth for the materials that make up most of the equatorial and mid- to moderately high-latitude regions of Mars. The six landing sites sample two of the three dominant global thermal inertia and albedo units that cover ~80% of the surface of Mars. The Viking, Spirit, Mars Pathfinder, and Phoenix landing sites are representative of the moderate to high thermal inertia and intermediate to high albedo unit that is dominated by crusty, cloddy, blocky or frozen soils (duricrust that may be layered) with various abundances of rocks and bright dust. The Opportunity landing site is representative of the moderate to high thermal inertia and low albedo surface unit that is relatively dust free and composed of dark eolian sand and/or increased abundance of rocks. Rock abundance derived from orbital thermal differencing techniques in the equatorial regions agrees with that determined from rock counts at the surface and varies from ~3-20% at the landing sites. The size-frequency distributions of rocks >1.5 m diameter fully resolvable in HiRISE images of the landing sites follow exponential models developed from lander measurements of smaller rocks and are continuous with these rock distributions indicating both are part of the same population. Interpretation of radar data confirms the presence of load bearing, relatively dense surfaces controlled by the soil type at the landing sites, regional rock populations from diffuse scattering similar to those observed directly at the sites, and root-mean-squared slopes that compare favorably

  19. A COUPLED LAND-SURFACE AND DRY DEPOSITION MODEL AND COMPARISON TO FIELD MEASUREMENTS OF SURFACE HEAT, MOISTURE, AND OZONE FLUXES

    EPA Science Inventory

    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...

  20. Sensitivity of land surface and Cumulus schemes for Thunderstorm prediction

    NASA Astrophysics Data System (ADS)

    Kumar, Dinesh; Mohanty, U. C.; Kumar, Krishan

    2016-06-01

    The cloud processes play an important role in all forms of precipitation. Its proper representation is one of the challenging tasks in mesoscale numerical simulation. Studies have revealed that mesoscale feature require proper initialization which may likely to improve the convective system rainfall forecasts. Understanding the precipitation process, model initial condition accuracy and resolved/sub grid-scale precipitation processes representation, are the important areas which needed to improve in order to represent the mesoscale features properly. Various attempts have been done in order to improve the model performance through grid resolution, physical parameterizations, etc. But it is the physical parameterizations which provide a convective atmosphere for the development and intensification of convective events. Further, physical parameterizations consist of cumulus convection, surface fluxes of heat, moisture, momentum, and vertical mixing in the planetary boundary layer (PBL). How PBL and Cumulus schemes capture the evolution of thunderstorm have been analysed by taking thunderstorm cases occurred over Kolkata, India in the year 2011. PBL and cumulus schemes were customized for WSM-6 microphysics because WSM series has been widely used in operational forecast. Results have shown that KF (PBL scheme) and WSM-6 (Cumulus Scheme) have reproduced the evolution of surface variable such as CAPE, temperature and rainfall very much like observation. Further, KF and WSM-6 scheme also provided the increased moisture availability in the lower atmosphere which was taken to higher level by strong vertical velocities providing a platform to initiate a thunderstorm much better. Overestimation of rain in WSM-6 occurs primarily because of occurrence of melting and freezing process within a deeper layer in WSM-6 scheme. These Schemes have reproduced the spatial pattern and peak rainfall coverage closer to TRMM observation. It is the the combination of WSM-6, and KF schemes

  1. A geometric performance assessment of the EO-1 advanced land imager

    USGS Publications Warehouse

    Storey, J.C.; Choate, M.J.; Meyer, D.J.

    2004-01-01

    The Earth Observing 1 (EO-1) Advanced Land Imager (ALI) demonstrates technology applicable to a successor system to the Landsat Thematic Mapper series. A study of the geometric performance characteristics of the ALI was conducted under the auspices of the EO-1 Science Validation Team. This study evaluated ALI performance with respect to absolute pointing knowledge, focal plane sensor chip assembly alignment, and band-to-band registration for purposes of comparing this new technology to the heritage Landsat systems. On-orbit geometric calibration procedures were developed that allowed the generation of ALI geometrically corrected products that compare favorably with their Landsat 7 counterparts with respect to absolute geodetic accuracy, internal image geometry, and band registration.

  2. Land-surface temperature measurement from space - Physical principles and inverse modeling

    NASA Technical Reports Server (NTRS)

    Wan, Zhengming; Dozier, Jeff

    1989-01-01

    To apply the multiple-wavelength (split-window) method used for satellite measurement of sea-surface temperature from thermal-infrared data to land-surface temperatures, the authors statistically analyze simulations using an atmospheric radiative transfer model. The range of atmospheric conditions and surface temperatures simulated is wide enough to cover variations in clear atmospheric properties and surface temperatures, both of which are larger over land than over sea. Surface elevation is also included in the simulation as the most important topographic effect. Land covers characterized by measured or modeled spectral emissivities include snow, clay, sands, and tree leaf samples. The empirical inverse model can estimate the surface temperature with a standard deviation less than 0.3 K and a maximum error less than 1 K, for viewing angles up to 40 degrees from nadir under cloud-free conditions, given satellite measurements in three infrared channels. A band in the region from 10.2 to 11.0 microns will usually give the most reliable single-band estimate of surface temperature. In addition, a band in either the 3.5-4.0-micron region or in the 11.5-12.6-micron region must be included for accurate atmospheric correction, and a band below the ozone absorption feature at 9.6 microns (e.g., 8.2-8.8 microns) will increase the accuracy of the estimate of surface temperature.

  3. Land and natural resource information and some potential environmental effects of surface mining of coal in the Gillette area, Wyoming

    USGS Publications Warehouse

    Keefer, William Richard; Hadley, R.F.

    1976-01-01

    Campbell County, along the east margin of the Powder River Basin in northeastern Wyoming, contains more coal than any other county in the United States. The principal deposit is the Wyodak-Anderson coal bed. The bed is 50-100 feet (15-30 meters) thick over large areas, lies less than 200 feet (60 meters) deep in a north-south trending strip nearly 100 miles (161 kilometers) long and 2-3 miles (3-5 kilometers) wide, and contains an estimated 15 billion tons (13.6 billion metric tons) of sub-bituminous, low-sulfur coal that is presently considered to be accessible to surface mining. Extensive mining of this deposit has the potential for causing a variety of environmental impacts and has been a matter of much public concern and debate in recent years. An integrated program of geologic, hydrologic, geochemical, and related studies by the U.S. Geological Survey in central Campbell County provides basic information about the land and its resources, including (1) characteristics of the landscape, (2) properties of rocks and surface materials, (3) depth and thickness of coal, (4) streamflow, (5) depth to ground water, (6) quality of ground water, (7) sediment yield, (8) concentrations of trace elements in soils, rocks, coal, vegetation, and water, and (9) current land use. The data are used to analyze and predict some of the potential environmental effects of surface mining, such as the extent of land disturbance, nature and degree of landscape modification, and disruption of surface-water and ground-water systems. Advance knowledge and understanding of these and other problems are useful in the planning and regulation of future leasing, mining, reclamation, and related activities.

  4. Multispectral remote sensing contribution to land surface evaporation

    NASA Technical Reports Server (NTRS)

    Choudhury, B. J.

    1990-01-01

    The global water cycle is perhaps the most important of all the biogeochemical cycles and evaporation, which is a significant component of the water cycle, is also linked with the energy and carbon cycles. Long-term evaporation over large areas has generally been computed as the difference of precipitation and river runoff. Analysis of short-term evaporation rate and its spatial pattern, however, is extremely complex, and multispectral remotely sensed data could aid in such analysis. Multispectral data considered here are visible and near-infrared reflectances, infrared surface temperature and the 37 GHz brightness temperatures. These observations are found to be not totally independent of each other. A few of their relationships are established and discussed considering physically-based models.

  5. A Revised Force Restore Model for Land Surface Modeling.

    NASA Astrophysics Data System (ADS)

    Ren, Diandong; Xue, Ming

    2004-11-01

    To clarify the definition of the equation for the temperature toward which the soil skin temperature is restored, the prediction equations in the commonly used force restore model for soil temperature are rederived from the heat conduction equation. The derivation led to a deep-layer temperature, commonly denoted T2, that is defined as the soil temperature at depth πd plus a transient term, where d is the e-folding damping depth of soil temperature diurnal oscillations. The corresponding prediction equation for T2 has the same form as the commonly used one except for an additional term involving the lapse rate of the “seasonal mean” soil temperature and the damping depth d. A term involving the same also appears in the skin temperature prediction equation, which also includes a transient term. In the literature, T2 was initially defined as the short-term (over several days) mean of the skin temperature, but in practice it is often used as the deep-layer temperature. Such inconsistent use can lead to drift in T2 prediction over a several-day period, as is documented in this paper. When T2 is properly defined and initialized, large drift in T2 prediction is avoided and the surface temperature prediction is usually improved. This is confirmed by four sets of experiments, each for a period during each season of 2000, that are initialized using and verified against measurements of the Oklahoma Atmospheric Surface-Layer Instrumentation System (OASIS) project.


  6. Geothermal Heat Flux Assessment Using Remote Sensing Land Surface Temperature and Simulated Data. Case Studies at the Kenyan Rift and Yellowstone Geothermal Areas

    NASA Astrophysics Data System (ADS)

    Romaguera, M.; Vaughan, R. G.; Ettema, J.; Izquierdo-Verdiguier, E.; Hecker, C.; van der Meer, F. D.

    2015-12-01

    In this work we propose an innovative approach to assess the geothermal heat flux anomalies in the regions of the Kenyan Rift and the Yellowstone geothermal areas. The method is based on the land surface temperature (LST) differences obtained between remote sensing data and land surface model simulations. The hypothesis is that the model simulations do not account for the subsurface geothermal heat source in the formulation. Remote sensing of surface emitted radiances is able to detect at least the radiative portion of the geothermal signal that is not in the models. Two methods were proposed to assess the geothermal component of LST (LSTgt) based on the aforementioned hypothesis: a physical model and a data mining approach. The LST datasets were taken from the Land Surface Analysis Satellite Application Facilities products over Africa and the Copernicus Programme for North America, at a spatial resolution of 3-5 km. These correspond to Meteosat Second Generation and Geostationary Operational Environmental Satellite system satellites data respectively. The Weather Research and Forecasting model was used to simulate LST based on atmospheric and surface characteristics using the Noah land surface model. The analysis was carried out for a period of two months by using nighttime acquisitions. Higher spatial resolution images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer data were also used on the Kenyan area to produce similar outputs employing existing methods. The comparison of the results from both methods and areas illustrated the potential of the data and methodologies for geothermal applications.

  7. Land-atmosphere CO2 exchange simulated by a land surface process model coupled to an atmospheric general circulation model

    NASA Astrophysics Data System (ADS)

    Bonan, Gordon B.

    1995-02-01

    CO2 uptake during plant photosynthesis and CO2 loss during plant and microbial respiration were added to a land surface process model to simulate the diurnal and annual cycles of biosphere-atmosphere CO2 exchange. The model was coupled to a modified version of the National Center for Atmospheric Research (NCAR) Community Climate Model version 2 (CCM2), and the coupled model was run for 5 years. The geographic patterns of annual net primary production are qualitatively similar to other models. When compared by vegetation type, annual production and annual microbial respiration are consistent with other models, except for needleleaf evergreen tree vegetation, where production is too high, and semidesert vegetation, where production and microbial respiration are too low. The seasonality of the net CO2 flux agrees with other models in the southern hemisphere and the tropics. The diurnal range is large for photosynthesis and lower for plant and microbial respiration, which agrees with qualitative expectations. The simulation of the central United States is poor due to temperature and precipitation biases in the coupled model. Despite these deficiencies the current approach is a promising means to include terrestrial CO2 fluxes in a climate system model that simulates atmospheric CO2 concentrations, because it alleviates important parameterization discrepancies between standard biogeochemical models and the land surface models typically used in general circulation models, and because the model resolves the diurnal range of CO2 exchange, which can be large (15 - 45 micromol CO2 sq m/s).

  8. Improvement of subsurface process in land surface modeling including lateral flow under unsaturated zone

    NASA Astrophysics Data System (ADS)

    Kim, J.; Mohanty, B.

    2013-12-01

    Lateral subsurface flow is an important component in local water budgets through its direct impact on soil moisture. However, most of the land surface models are one-dimensional considering only vertical interactions and neglecting the horizontal flow of water at the grid or sub-grid scales. Subsurface flow can be affected by surface topography and non-homogenous soil properties controlling the lateral flow of water. In this study, we improved the subsurface flow process in land surface model (Community Land Model, CLM) by considering the lateral flow based on topography and heterogeneous soil hydraulic properties in unsaturated zone. The changes in flow direction derived from topographic factor are used to consider the lateral movement of water at the near surface. Furthermore, vertical and horizontal hydraulic conductivities for each layer in unsaturated zone are estimated using different averaging methods and anisotropic factors. Based on the hydraulic conductivities of each layer for heterogeneous soil profiles we considered lateral flow of soil water between soil columns. These approaches were tested at several different sites (e.g. field and watershed scales). The results showed the appropriate vertical and horizontal hydraulic conductivities with depth for each site and the improved subsurface flow process by considering the lateral flow in land surface models.

  9. Resolution and Content Improvements to MISR Aerosol and Land Surface Products

    NASA Astrophysics Data System (ADS)

    Garay, M. J.; Bull, M. A.; Diner, D. J.; Hansen, E. G.; Kalashnikova, O. V.

    2015-12-01

    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. The performance of the aerosol product has been validated against ground-based Aerosol Robotic Network (AERONET) observations, model comparisons, and climatological assessments. This product has played a major role in studies of the impacts of aerosols on climate and air quality. The surface product has found a variety of uses, particularly at regional scales for assessing vegetation and land surface change. A major development effort has led to the release of an update to the operational (Version 22) MISR Level 2 aerosol and land surface retrieval products, which has been in production since December 2007. The new release is designated Version 23. The 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 and present validation of the aerosol product against both the standard AERONET historical database, as well as high spatial density AERONET-DRAGON deployments. Comparisons will also be shown relative to the Version 22 aerosol and land surface products. Applications enabled by these product updates will be discussed.

  10. 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.

  11. Stable water isotope simulation by current land-surface schemes:Results of IPILPS phase 1

    SciTech Connect

    Henderson-Sellers, A.; Fischer, M.; Aleinov, I.; McGuffie, K.; Riley, W.J.; Schmidt, G.A.; Sturm, K.; Yoshimura, K.; Irannejad, P.

    2005-10-31

    Phase 1 of isotopes in the Project for Intercomparison of Land-surface Parameterization Schemes (iPILPS) compares the simulation of two stable water isotopologues ({sup 1}H{sub 2} {sup 18}O and {sup 1}H{sup 2}H{sup 16}O) at the land-atmosphere interface. The simulations are off-line, with forcing from an isotopically enabled regional model for three locations selected to offer contrasting climates and ecotypes: an evergreen tropical forest, a sclerophyll eucalypt forest and a mixed deciduous wood. Here we report on the experimental framework, the quality control undertaken on the simulation results and the method of intercomparisons employed. The small number of available isotopically-enabled land-surface schemes (ILSSs) limits the drawing of strong conclusions but, despite this, there is shown to be benefit in undertaking this type of isotopic intercomparison. Although validation of isotopic simulations at the land surface must await more, and much more complete, observational campaigns, we find that the empirically-based Craig-Gordon parameterization (of isotopic fractionation during evaporation) gives adequately realistic isotopic simulations when incorporated in a wide range of land-surface codes. By introducing two new tools for understanding isotopic variability from the land surface, the Isotope Transfer Function and the iPILPS plot, we show that different hydrological parameterizations cause very different isotopic responses. We show that ILSS-simulated isotopic equilibrium is independent of the total water and energy budget (with respect to both equilibration time and state), but interestingly the partitioning of available energy and water is a function of the models' complexity.

  12. Comparing atmosphere-land surface feedbacks from models within the tropics (CALM). Part 1: Evaluation of CMIP5 GCMs to simulate the land surface-atmosphere feedback

    NASA Astrophysics Data System (ADS)

    Williams, C.; Allan, R.; Kniveton, D.

    2012-04-01

    Man-made transformations to the environment, and in particular the land surface, are having a large impact on the distribution (in both time and space) of rainfall, upon which all life is reliant. From global changes in the composition of the atmosphere, through the emission of greenhouse gases and aerosols, to more localised land use and land cover changes due to an expanding population with an increasing ecological footprint, human activity has a considerable impact on the processes controlling rainfall. This is of particular importance for environmentally vulnerable regions such as many of those in the tropics. Here, widespread poverty, an extensive disease burden and pockets of political instability has resulted in a low resilience and limited adaptative capacity to climate related shocks and stresses. Recently, the 5th Climate Modelling Intercomparison Project (CMIP5) has run a number of state-of-the-art climate models using various present-day and future emission scenarios of greenhouse gases, and therefore provides an unprecedented amount of simulated model data. This paper presents the results of the first stage of a larger project, aiming to further our understanding of how the interactions between tropical rainfall and the land surface are represented in some of the latest climate model simulations. Focusing on precipitation, soil moisture and near-surface temperature, this paper compares the data from all of these models, as well as blended observational-satellite data, to see how the interactions between rainfall and the land surface differs (or agrees) between the models and reality. Firstly, in an analysis of the processes from the "observed" data, the results suggest a strong positive relationship between precipitation and soil moisture at both daily and seasonal timescales. There is a weaker and negative relationship between precipitation and temperature, and likewise between soil moisture and temperature. For all variables, the correlations are

  13. Bridging the Gap Between the iLEAPS and GEWEX Land-Surface Modeling Communities

    NASA Technical Reports Server (NTRS)

    Bonan, Gordon; Santanello, Joseph A., Jr.

    2013-01-01

    Models of Earth's weather and climate require fluxes of momentum, energy, and moisture across the land-atmosphere interface to solve the equations of atmospheric physics and dynamics. Just as atmospheric models can, and do, differ between weather and climate applications, mostly related to issues of scale, resolved or parameterised physics,and computational requirements, so too can the land models that provide the required surface fluxes differ between weather and climate models. Here, however, the issue is less one of scale-dependent parameterisations.Computational demands can influence other minor land model differences, especially with respect to initialisation, data assimilation, and forecast skill. However, the distinction among land models (and their development and application) is largely driven by the different science and research needs of the weather and climate communities.

  14. Remote Sensing of Urban Land Cover/Land Use Change, Surface Thermal Responses, and Potential Meteorological and Climate Change Impacts

    NASA Astrophysics Data System (ADS)

    Quattrochi, D. A.; Jedlovec, G.; Meyer, P. J.

    2011-12-01

    City growth influences the development of the urban heat island (UHI), but the effect that local meteorology has on the UHI is less well known. This paper presents some preliminary findings from a study that uses multitemporal Landsat TM and ASTER data to evaluate land cover/land use change (LULCC) over the NASA Marshall Space Flight Center (MFSC) and its Huntsville, AL metropolitan area. Landsat NLCD data for 1992 and 2001 have been used to evaluate LULCC for MSFC and the surrounding urban area. Land surface temperature (LST) and emissivity derived from NLCD data have also been analyzed to assess changes in these parameters in relation to LULCC. Additionally, LULCC, LST, and emissivity have been identified from ASTER data from 2001 and 2011 to provide a comparison with the 2001 NLCD and as a measure of current conditions within the study area. As anticipated, the multi-temporal NLCD and ASTER data show that significant changes have occurred in land covers, LST, and emissivity within and around MSFC. The patterns and arrangement of these changes, however, is significant because the juxtaposition of urban land covers within and outside of MSFC provides insight on what impacts at a local to regional scale, the inter-linkage of these changes potentially have on meteorology. To further analyze these interactions between LULCC, LST, and emissivity with the lower atmosphere, a network of eleven weather stations has been established across the MSFC property. These weather stations provide data at a 10 minute interval, and these data are uplinked for use by MSFC facilities operations and the National Weather Service. The weather data are also integrated within a larger network of meteorological stations across north Alabama. Given that the MSFC weather stations will operate for an extended period of time, they can be used to evaluate how the building of new structures, and changes in roadways, and green spaces as identified in the MSFC master plan for the future, will

  15. Remote Sensing of Urban Land Cover/Land Use Change, Surface Thermal Responses, and Potential Meteorological and Climate Change Impacts

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.; Jedlovec, Gary; Meyer, Paul

    2011-01-01

    City growth influences the development of the urban heat island (UHI), but the effect that local meteorology has on the UHI is less well known. This paper presents some preliminary findings from a study that uses multitemporal Landsat TM and ASTER data to evaluate land cover/land use change (LULCC) over the NASA Marshall Space Flight Center (MFSC) and its Huntsville, AL metropolitan area. Landsat NLCD data for 1992 and 2001 have been used to evaluate LULCC for MSFC and the surrounding urban area. Land surface temperature (LST) and emissivity derived from NLCD data have also been analyzed to assess changes in these parameters in relation to LULCC. Additionally, LULCC, LST, and emissivity have been identified from ASTER data from 2001 and 2011 to provide a comparison with the 2001 NLCD and as a measure of current conditions within the study area. As anticipated, the multi-temporal NLCD and ASTER data show that significant changes have occurred in land covers, LST, and emissivity within and around MSFC. The patterns and arrangement of these changes, however, is significant because the juxtaposition of urban land covers within and outside of MSFC provides insight on what impacts at a local to regional scale, the inter-linkage of these changes potentially have on meteorology. To further analyze these interactions between LULCC, LST, and emissivity with the lower atmosphere, a network of eleven weather stations has been established across the MSFC property. These weather stations provide data at a 10 minute interval, and these data are uplinked for use by MSFC facilities operations and the National Weather Service. The weather data are also integrated within a larger network of meteorological stations across north Alabama. Given that the MSFC weather stations will operate for an extended period of time, they can be used to evaluate how the building of new structures, and changes in roadways, and green spaces as identified in the MSFC master plan for the future, will

  16. Remote Sensing of the Surface Urban Heat Island and Land Architecture in Phoenix, Arizona: Combined Effects of Land Composition and Configuration and Cadastral-Demographic-Economic Factors

    NASA Astrophysics Data System (ADS)

    Middel, A. C.; LI, X.

    2015-12-01

    This study seeks to determine the role of land architecture—the composition and configuration of land cover—as well as cadastral-demographic-economic factors on land surface temperature (LST) and the surface urban heat island (SUHI) effect of Phoenix, Arizona. It employs 1 m National Agricultural Imagery Program data of land-cover with 120 m Landsat-derived land surface temperature decomposed to 30m, a new measure of configuration, the normalized moment of inertia, and U.S. Census data to address the question for two randomly selected samples comprising 523 and 545 residential neighborhoods (census blocks) in the city. The results indicate that, contrary to most other studies, land configuration maintains as strong a role in LST as does land composition. In addition, land architecture combined with cadastral, demographic and economic data, captures a significant amount of explained variance in LST. The results indicate that attention to land architecture in the development of or reshaping of neighborhoods may ameliorate the summer extremes in LST.

  17. INDICATION OF INSENSITIVITY OF PLANETARY WEATHERING BEHAVIOR AND HABITABLE ZONE TO SURFACE LAND FRACTION

    SciTech Connect

    Abbot, Dorian S.; Ciesla, Fred J.; Cowan, Nicolas B.

    2012-09-10

    It is likely that unambiguous habitable zone terrestrial planets of unknown water content will soon be discovered. Water content helps determine surface land fraction, which influences planetary weathering behavior. This is important because the silicate-weathering feedback determines the width of the habitable zone in space and time. Here a low-order model of weathering and climate, useful for gaining qualitative understanding, is developed to examine climate evolution for planets of various land-ocean fractions. It is pointed out that, if seafloor weathering does not depend directly on surface temperature, there can be no weathering-climate feedback on a waterworld. This would dramatically narrow the habitable zone of a waterworld. Results from our model indicate that weathering behavior does not depend strongly on land fraction for partially ocean-covered planets. This is powerful because it suggests that previous habitable zone theory is robust to changes in land fraction, as long as there is some land. Finally, a mechanism is proposed for a waterworld to prevent complete water loss during a moist greenhouse through rapid weathering of exposed continents. This process is named a 'waterworld self-arrest', and it implies that waterworlds can go through a moist greenhouse stage and end up as planets like Earth with partial ocean coverage. This work stresses the importance of surface and geologic effects, in addition to the usual incident stellar flux, for habitability.

  18. Estimated land-surface subsidence in Harris County, Texas, 1915-17 to 2001

    USGS Publications Warehouse

    Kasmarek, Mark C.; Gabrysch, Robert K.; Johnson, Michaela R.

    2009-01-01

    Land-surface subsidence, or land subsidence, in Harris County, Texas, which encompasses much of the Houston area, has been occurring for decades. Land subsidence has increased the frequency and extent of flooding, damaged buildings and transportation infrastructure, and caused adverse environmental effects. The primary cause of land subsidence in the Houston area is withdrawal of groundwater, although extraction of oil and gas also has contributed. Throughout most of the 20th century, groundwater was the primary source of municipal, agricultural, and industrial water supply for Harris County. Currently (2009) a transition to surface water as the primary source of supply, guided by a groundwater regulatory plan developed by the Harris-Galveston Subsidence District (2001), is in effect. The aquifers in Harris County contain an abundant amount of potable groundwater, but they also contain layers of clay. Groundwater withdrawals caused compaction of the clay layers, which in turn resulted in the widespread, substantial land-surface subsidence that has occurred in the Houston area.

  19. Impacts of wind farms on land surface temperature

    NASA Astrophysics Data System (ADS)

    Zhou, Liming; Tian, Yuhong; Baidya Roy, Somnath; Thorncroft, Chris; Bosart, Lance F.; Hu, Yuanlong

    2012-07-01

    The wind industry in the United States has experienced a remarkably rapid expansion of capacity in recent years and this fast growth is expected to continue in the future. While converting wind's kinetic energy into electricity, wind turbines modify surface-atmosphere exchanges and the transfer of energy, momentum, mass and moisture within the atmosphere. These changes, if spatially large enough, may have noticeable impacts on local to regional weather and climate. Here we present observational evidence for such impacts based on analyses of satellite data for the period of 2003-2011 over a region in west-central Texas, where four of the world's largest wind farms are located. Our results show a significant warming trend of up to 0.72°C per decade, particularly at night-time, over wind farms relative to nearby non-wind-farm regions. We attribute this warming primarily to wind farms as its spatial pattern and magnitude couples very well with the geographic distribution of wind turbines.

  20. On the Representation of Heterogeneity in Land-Surface-Atmosphere Coupling

    NASA Astrophysics Data System (ADS)

    de Vrese, Philipp; Schulz, Jan-Peter; Hagemann, Stefan

    2016-07-01

    A realistic representation of processes that are not resolved by the model grid is one of the key challenges in Earth-system modelling. In particular, the non-linear nature of processes involved makes a representation of the link between the atmosphere and the land surface difficult. This is especially so when the land surface is horizontally strongly heterogeneous. In the majority of present day Earth system models two strategies are pursued to couple the land surface and the atmosphere. In the first approach, surface heterogeneity is not explicitly accounted for, instead effective parameters are used to represent the entirety of the land surface in a model's grid box (parameter-aggregation). In the second approach, subgrid-scale variability at the surface is explicitly represented, but it is assumed that the blending height is located below the lowest atmospheric model level (simple flux-aggregation). Thus, in both approaches the state of the atmosphere is treated as being horizontally homogeneous within a given grid box. Based upon the blending height concept, an approach is proposed that allows for a land-surface-atmosphere coupling in which horizontal heterogeneity is considered not only at the surface, but also within the lowest layers of the atmosphere (the VERTEX scheme). Below the blending height, the scheme refines the turbulent mixing process with respect to atmospheric subgrid fractions, which correspond to different surface features. These subgrid fractions are not treated independently of each other, since an explicit horizontal component is integrated into the turbulent mixing process. The scheme was implemented into the JSBACH model, the land component of the Max Planck Institute for Meteorology's Earth-system model, when coupled to the atmospheric general circulation model ECHAM. The single-column version of the Earth system model is used in two example cases in order to demonstrate how the effects of surface heterogeneity are transferred into the

  1. Upper-soil moisture inter-comparison from SMOS's products and land surface models over the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Polcher, Jan; Barella-Ortiz, Anaïs; Aires, Filipe; Balsamo, Gianpaolo; Gelati, Emiliano; Rodríguez-Fernández, Nemesio

    2015-04-01

    Soil moisture is a key state variable of the hydrological cycle. It conditions runoff, infiltration and evaporation over continental surfaces, and is key for forecasting droughts and floods. It plays thus an important role in surface-atmosphere interactions. Surface Soil Moisture (SSM) can be measured by in situ measurements, by satellite observations or modelled using land surface models. As a complementary tool, data assimilation can be used to combine both modelling and satellite observations. The work presented here is an inter-comparison of retrieved and modelled SSM data, for the 2010 - 2012 period, over the Iberian Peninsula. The region has been chosen because its vegetation cover is not very dense and includes strong contrasts in the rainfall regimes and thus a diversity of behaviours for SSM. Furthermore this semi-arid region is strongly dependent on a good management of its water resources. Satellite observations correspond to the Soil Moisture and Ocean Salinity (SMOS) retrievals: the L2 product from an optimal interpolation retrieval, and 3 other products using Neural Network retrievals with different input information: SMOS time indexes, purely SMOS data, or addition of the European Advanced Scaterometer (ASCAT) backscattering, and the Moderate-Resolution Imaging Spectrometer (MODIS) surface temperature information. The modelled soil moistures have been taken from the ORCHIDEE (ORganising Carbon and Hydrology In Dynamic EcosystEms) and the HTESSEL (Hydrology-Tiled ECMWF Scheme for Surface Exchanges over Land) land surface models. Both models are forced with the same atmospheric conditions (as part of the Earth2Observe FP7 project) over the period but they represent the surface soil moisture with very different degrees of complexity. ORCHIDEE has 5 levels in the top 5 centimetres of soil while in HTESSEL this variable is part of the top soil moisture level. The two types of SMOS retrievals are compared to the model outputs in their spatial and temporal

  2. Impact of high resolution land surface initialization in Indian summer monsoon simulation using a regional climate model

    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.

  3. Impact of Agricultural Practice on Regional Climate in a CoupledLand Surface Mesoscale Model

    SciTech Connect

    Cooley, H.S.; Riley, W.J.; Torn, M.S.; He, Y.

    2004-07-01

    The land surface has been shown to form strong feedbacks with climate due to linkages between atmospheric conditions and terrestrial ecosystem exchanges of energy, momentum, water, and trace gases. Although often ignored in modeling studies, land management itself may form significant feedbacks. Because crops are harvested earlier under drier conditions, regional air temperature, precipitation, and soil moisture, for example, affect harvest timing, particularly of rain-fed crops. This removal of vegetation alters the land surface characteristics and may, in turn, affect regional climate. We applied a coupled climate(MM5) and land-surface (LSM1) model to examine the effects of early and late winter wheat harvest on regional climate in the Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility in the Southern Great Plains, where winter wheat accounts for 20 percent of the land area. Within the winter wheat region, simulated 2 m air temperature was 1.3 C warmer in the Early Harvest scenario at mid-day averaged over the two weeks following harvest. Soils in the harvested area were drier and warmer in the top 10 cm and wetter in the 10-20 cm layer. Midday soils were 2.5 C warmer in the harvested area at mid-day averaged over the two weeks following harvest. Harvest also dramatically altered latent and sensible heat fluxes. Although differences between scenarios diminished once both scenarios were harvested, the short-term impacts of land management on climate were comparable to those from land cover change demonstrated in other studies.

  4. Assimilating Spaceborne Passive Microwave Measurements into a Land Surface Model to Estimate Snow Water Equivalent in the Yampa River Basin

    NASA Astrophysics Data System (ADS)

    Kim, R. S.; Li, D.; Durand, M. T.

    2014-12-01

    Acquiring accurate spatiotemporal snow information over large areas for understanding snowcover in the global and regional water and energy balances is crucial and has motivated snow characterization via remote sensing. The passive microwave (PM) measurements have been widely used and invested in order to obtain information about snowpack properties. In this paper, we utilize a snow data assimilation system to estimate snow water equivalent (SWE) in the Yampa River basin in the Colorado Rockies within the NASA Cold Land Processes Experiment (CLPX) area of 2002-2003. The Advanced Microwave Scanning Radiometer Earth Observing System (AMSR-E) observations were used. Forcing data were derived from the North American Land Data Assimilation v2 (NLDAS-2) dataset. Also, the Microwave Emission Model of Layered Snowpacks (MEMLS) was used to convert the snow state variables to brightness temperatures. The ensemble Kalman filter was directly employed to assimilate PM brightness temperature data into a land surface model snow scheme. Assimilation results are compared with SNOTEL and snow course observations.

  5. Data-Driven Surface Traversability Analysis for Mars 2020 Landing Site Selection

    NASA Technical Reports Server (NTRS)

    Ono, Masahiro; Rothrock, Brandon; Almeida, Eduardo; Ansar, Adnan; Otero, Richard; Huertas, Andres; Heverly, Matthew

    2015-01-01

    The objective of this paper is three-fold: 1) to describe the engineering challenges in the surface mobility of the Mars 2020 Rover mission that are considered in the landing site selection processs, 2) to introduce new automated traversability analysis capabilities, and 3) to present the preliminary analysis results for top candidate landing sites. The analysis capabilities presented in this paper include automated terrain classification, automated rock detection, digital elevation model (DEM) generation, and multi-ROI (region of interest) route planning. These analysis capabilities enable to fully utilize the vast volume of high-resolution orbiter imagery, quantitatively evaluate surface mobility requirements for each candidate site, and reject subjectivity in the comparison between sites in terms of engineering considerations. The analysis results supported the discussion in the Second Landing Site Workshop held in August 2015, which resulted in selecting eight candidate sites that will be considered in the third workshop.

  6. Vegetation controls on surface heat flux partitioning, and land-atmosphere coupling

    NASA Astrophysics Data System (ADS)

    Williams, Ian N.; Torn, Margaret S.

    2015-11-01

    We provide observational evidence that land-atmosphere coupling is underestimated by a conventional metric defined by the correlation between soil moisture and surface evaporative fraction (latent heat flux normalized by the sum of sensible and latent heat flux). Land-atmosphere coupling is 3 times stronger when using leaf area index as a correlate of evaporative fraction instead of soil moisture, in the Southern Great Plains. The role of vegetation was confirmed using adjacent flux measurement sites having identical atmospheric forcing but different vegetation phenology. Transpiration makes the relationship between evaporative fraction and soil moisture nonlinear and gives the appearance of weak coupling when using linear soil moisture metrics. Regions of substantial coupling extend to semiarid and humid continental climates across the United States, in terms of correlations between vegetation metrics and evaporative fraction. The hydrological cycle is more tightly constrained by the land surface than previously inferred from soil moisture.

  7. Dissolved phosphorus transport from soil to surface water in catchments with different land use.

    PubMed

    Verheyen, Dries; Van Gaelen, Nele; Ronchi, Benedicta; Batelaan, Okke; Struyf, Eric; Govers, Gerard; Merckx, Roel; Diels, Jan

    2015-03-01

    Diffuse phosphorus (P) export from agricultural land to surface waters is a significant environmental problem. It is critical to determine the natural background P losses from diffuse sources, but their identification and quantification is difficult. In this study, three headwater catchments with differing land use (arable, pasture and forest) were monitored for 3 years to quantify exports of dissolved (<0.45 µm) reactive P and total dissolved P. Mean total P exports from the arable catchment ranged between 0.08 and 0.28 kg ha(-1) year(-1). Compared with the reference condition (forest), arable land and pasture exported up to 11-fold more dissolved P. The contribution of dissolved (<0.45 µm) unreactive P was low to negligible in every catchment. Agricultural practices can exert large pressures on surface waters that are controlled by hydrological factors. Adapting policy to cope with these factors is needed for lowering these pressures in the future. PMID:25681980

  8. WRF Simulation over the Eastern Africa by use of Land Surface Initialization

    NASA Astrophysics Data System (ADS)

    Sakwa, V. N.; Case, J.; Limaye, A. S.; Zavodsky, B.; Kabuchanga, E. S.; Mungai, J.

    2014-12-01

    The East Africa region experiences severe weather events associated with hazards of varying magnitude. It receives heavy precipitation which leads to wide spread flooding and lack of sufficient rainfall in some parts results into drought. Cases of flooding and drought are two key forecasting challenges for the Kenya Meteorological Service (KMS). The source of heat and moisture depends on the state of the land surface which interacts with the boundary layer of the atmosphere to produce excessive precipitation or lack of it that leads to severe drought. The development and evolution of precipitation systems are affected by heat and moisture fluxes from the land surface 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 numerical weather prediction models. Improved modeling capabilities within the region have the potential to enhance forecast guidance in support of daily operations and high-impact weather over East Africa. KMS currently runs a configuration of the Weather Research and Forecasting (WRF) model in real time to support its daily forecasting operations, invoking the Non-hydrostatic Mesoscale Model (NMM) dynamical core. They make use of the National Oceanic and Atmospheric Administration / National Weather Service Science and Training Resource Center's Environmental Modeling System (EMS) to manage and produce the WRF-NMM model runs on a 7-km regional grid over Eastern Africa.SPoRT and SERVIR provide land surface initialization datasets and model verification tool. The NASA Land Information System (LIS) provide real-time, daily soil initialization data in place of interpolated Global Forecast System soil moisture and temperature data. Model verification is done using the Model Evaluation Tools (MET) package, in order

  9. Modifying a dynamic global vegetation model for simulating large spatial scale land surface water balance

    NASA Astrophysics Data System (ADS)

    Tang, G.; Bartlein, P. J.

    2012-01-01

    Water balance models of simple structure are easier to grasp and more clearly connect cause and effect than models of complex structure. Such models are essential for studying large spatial scale land surface water balance in the context of climate and land cover change, both natural and anthropogenic. This study aims to (i) develop a large spatial scale water balance model by modifying a dynamic global vegetation model (DGVM), and (ii) test the model's performance in simulating actual evapotranspiration (ET), soil moisture and surface runoff for the coterminous United States (US). Toward these ends, we first introduced development of the "LPJ-Hydrology" (LH) model by incorporating satellite-based land covers into the Lund-Potsdam-Jena (LPJ) DGVM instead of dynamically simulating them. We then ran LH using historical (1982-2006) climate data and satellite-based land covers at 2.5 arc-min grid cells. The simulated ET, soil moisture and surface runoff were compared to existing sets of observed or simulated data for the US. The results indicated that LH captures well the variation of monthly actual ET (R2 = 0.61, p < 0.01) in the Everglades of Florida over the years 1996-2001. The modeled monthly soil moisture for Illinois of the US agrees well (R2 = 0.79, p < 0.01) with the observed over the years 1984-2001. The modeled monthly stream flow for most 12 major rivers in the US is consistent R2 > 0.46, p < 0.01; Nash-Sutcliffe Coefficients >0.52) with observed values over the years 1982-2006, respectively. The modeled spatial patterns of annual ET and surface runoff are in accordance with previously published data. Compared to its predecessor, LH simulates better monthly stream flow in winter and early spring by incorporating effects of solar radiation on snowmelt. Overall, this study proves the feasibility of incorporating satellite-based land-covers into a DGVM for simulating large spatial scale land surface water balance. LH developed in this study should be a useful

  10. Coupling TOUGH2 with CLM3: Developing a Coupled Land Surface andSubsurface Model

    SciTech Connect

    Pan, Lehua; Jin, Jiming; Miller, Norman; Wu, Yu-Shu; Bodvarsson,Gudmundur

    2006-05-19

    An understanding of the hydrologic interactions among atmosphere, land surface, and subsurface is one of the keys to understanding the water cycling system that supports life on earth. The inherent coupled processes and complex feedback structures among subsystems make such interactions difficult to simulate. In this paper, we present a model that simulates the land surface and subsurface hydrologic response to meteorological forcing. This model combines a state-of-the-art land-surface model, the NCAR Community Land Model version 3 (CLM3), with a variably saturated groundwater model, TOUGH2, through an internal interface that includes flux and state variables shared by the two submodels. Specifically, TOUGH2 uses infiltration, evaporation, and root-uptake rates, calculated by CLM3, as source/sink terms in its simulation; CLM3 uses satu