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Sample records for trailside snowcover rpd-49

  1. Fractional Snow-Cover Mapping Through Artificial Neural Network Analysis of MODIS Surface Reflectance. 

    E-Print Network [OSTI]

    Dobreva, Iliyana D.

    2010-07-14

    Accurate areal measurements of snow-cover extent are important for hydrological and climate modeling. The traditional method of mapping snow cover is binary where a pixel is approximated to either snow-covered or snow-free. Fractional snow cover...

  2. Retrieval of subpixel snow-covered area and grain size from imaging spectrometer data

    E-Print Network [OSTI]

    Dozier, Jeff

    Retrieval of subpixel snow-covered area and grain size from imaging spectrometer data Thomas H 2002 Abstract We describe and validate an automated model that retrieves subpixel snow-covered area multiple endmember spectral mixtures with a spectral library of snow, vegetation, rock, and soil. We derive

  3. Snow-Cover Condition in Japan and Damage of the Sugi (Cryptomeria Japonica D. Don)'

    E-Print Network [OSTI]

    Snow-Cover Condition in Japan and Damage of the Sugi (Cryptomeria Japonica D. Don)' HideakiTaira2 of Honshu (the main island), along the Japan Sea has heavy snow in winter. In some places, snow piles up more than four meters and the ground is coverd with snow about one hundred and forty days a year

  4. The Effect of Grain Size on Spectral Mixture Analysis of Snow-Covered Area from

    E-Print Network [OSTI]

    Dozier, Jeff

    The Effect of Grain Size on Spectral Mixture Analysis of Snow-Covered Area from AVIRIS Data Thomas to improve spectral mixture Results were verified with a high spatial resolution aerial analysis of snow of multiple snow endmembers. Snow reflectance of fraction under/overflow and residuals confirmed mix- in near

  5. Statistical evaluation of remotely sensed snow-cover products with constraints from streamflow and SNOTEL measurements

    E-Print Network [OSTI]

    Texas at San Antonio, University of

    Statistical evaluation of remotely sensed snow-cover products with constraints from streamflow and SNOTEL measurements Xiaobing Zhoua,*, Hongjie Xieb , Jan M.H. Hendrickxa a Department of Earth; accepted 26 October 2004 Abstract Using streamflow and Snowpack Telemetry (SNOTEL) measurements

  6. Carbon and Nitrogen Cycling in Snow-Covered Environments

    E-Print Network [OSTI]

    Grogan, Paul

    snow cover through shading, wind sheltering, and interception. Changes in snow cover associated and nitrogen cycling. Introduction Approximately 60% of the terrestrial earth surface experiences seasonal snow

  7. Snowpack controls on nitrogen cycling and export in seasonally snow-covered catchments

    E-Print Network [OSTI]

    Williams, Mark W.

    a conceptual model of how snow cover controls subnivial (below snowpack) microbial processes and N leachate and there is little microbial activity and N leachate is high. In zone II, total microbial activity is highly variable and the amount of N leachate is highly variable. In zone III, total microbial activity is high

  8. Submitted to the Arctic Centre on April 22, 2003 A snow-cover experiment at Tarfala Research Station

    E-Print Network [OSTI]

    Moore, John

    , drills, shovels and spades, but by radio waves as well. In the present report we investigate whether elaborate snow-pit digging for direct visual observations. #12;3 Figure 0. Schematic diagram

  9. MODIS snow albedo bias at high solar zenith angles relative to theory and to in situ observations in Greenland

    E-Print Network [OSTI]

    Wang, Xianwei; Zender, Charles S

    2010-01-01

    speci?c surface area of dry snow: Isothermal and temperatureresponse from black carbon in snow. Journal of Geophysicalassessment of the MODIS snow-cover products. Hydrological

  10. Daytime Arctic Cloud Detection based on Multi-angle Satellite Data with Case Studies

    E-Print Network [OSTI]

    Yu, Bin

    that the strongest dependences of surface air temperatures on increasing atmospheric carbon dioxide levels will occur of the similar remote sensing characteristics of clouds, ice- and snow-covered surfaces. This paper proposes two

  11. A comparison of AMSR-E/Aqua snow products with in situ observations and MODIS snow cover products in the Mackenzie River Basin, Canada

    E-Print Network [OSTI]

    Tong, J; Velicogna, I; Velicogna, I

    2010-01-01

    MODIS images-potential for snow cover mapping. Water Resour.R.D. Northern hemisphere snow cover variability and changeof remotely sensed snow-cover products with constraints from

  12. A Comparison of AMSR-E/Aqua Snow Products with in situ Observations and MODIS Snow Cover Products in the Mackenzie River Basin, Canada

    E-Print Network [OSTI]

    Tong, Jinjun; Velicogna, Isabella

    2010-01-01

    MODIS images-potential for snow cover mapping. Water Resour.R.D. Northern hemisphere snow cover variability and changeof remotely sensed snow-cover products with constraints from

  13. Present-day climate forcing and response from black carbon in snow

    E-Print Network [OSTI]

    Flanner, Mark G; Zender, Charles S; Randerson, James T; Rasch, Philip J

    2007-01-01

    profiles in Antarctic snow and ice, J. Glaciol. , 39(131),Soot climate forcing via snow and ice albedos, Proc. Natl.2003), Retrieval of subpixel snow-covered area and grain

  14. Fall and Winter Energy-Saving Tips | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    from the Sun Photo of a window with the curtains open. Sun is shining into the room and snow-covered mountains are visible outside. Copyright iStockphoto.comGiorgio Fochesato....

  15. Improving snow albedo processes in WRF/SSiB regional climate model to assess impact of dust and black carbon in snow on surface energy balance and hydrology over western U.S.

    E-Print Network [OSTI]

    2015-01-01

    in snow, and surface water and energy balances in of?inesnow and surface/soil water and energy balances (Figure 1).albedo can affect the water and energy balance, snowcover

  16. Recent advances in remote sensing of seasonal snow Anne W. NOLIN

    E-Print Network [OSTI]

    Kurapov, Alexander

    . Innovations in sensor technology and digital image proces- sing allow scientists to visualize and monitor snow advances within the past decade. 2. SNOW-COVER EXTENT 2.1. Binary classification of snow cover The unique classification in which each pixel in an image is designated as `snow' or `non-snow' or a fractional snow

  17. Robust Horizon Detection using Segmentation for UAV Applications Nasim Sepehri Boroujeni, S. Ali Etemad

    E-Print Network [OSTI]

    Whitehead, Anthony

    for various types of terrains from water to ground, and even snow-covered ground. Finally, it is shown of the eyes and brain of an operator for controlling an automated vehicle. Automated cars, unmanned aerial ve of collision or failure, has been subject to extensive research [2]. Obstacle detection for UAVs is the first

  18. Retrieval of subpixel snow covered area, grain size, and albedo from MODIS Thomas H. Painter a,

    E-Print Network [OSTI]

    Dozier, Jeff

    Retrieval of subpixel snow covered area, grain size, and albedo from MODIS Thomas H. Painter a Keywords: Snow Grain size Albedo Spectral mixture analysis MODIS We describe and validate a model that retrieves fractional snow-covered area and the grain size and albedo of that snow from surface reflectance

  19. Sub-grid parameterization of snow distribution for an energy and mass balance snow cover model

    E-Print Network [OSTI]

    Sub-grid parameterization of snow distribution for an energy and mass balance snow cover model-element scale variability in snow accumulation and ablation is increasingly recognized as important spatial variability in snow accumulation and melt. Model state variables are snow-covered area average

  20. Snow water equivalent along elevation gradients in the Merced and Tuolumne River basins of the Sierra Nevada

    E-Print Network [OSTI]

    Dozier, Jeff

    Snow water equivalent along elevation gradients in the Merced and Tuolumne River basins fractional snow-covered area (SCA) at 500 m resolution to estimate snow water equivalent (SWE) across) blending the fractional SCA with SWE interpolated from snow-pillow measurements; and (2) retrospectively

  1. 864 IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 36, NO. 3, MAY 1998 Radar Measurements of Snow

    E-Print Network [OSTI]

    Sarabandi, Kamal

    of Snow: Experiment and Analysis John R. Kendra, Member, IEEE, Kamal Sarabandi, Senior Member, IEEE conducted to improve our understanding of radar backscatter from snow-covered ground surfaces. The first experiment involves radar backscatter measurements at C- and X-band of artificial snow of varying depths

  2. Spatial Snow Cover Processes at Kuhtai and Reynolds David Tarboton, Gunter Bloschl, Keith Cooley,

    E-Print Network [OSTI]

    Tarboton, David

    7 Spatial Snow Cover Processes at Ku¨htai and Reynolds Creek David Tarboton, Gu¨nter Blo and understanding the spatio-temporal variability of snow-related quantities plays a key role in catchment hydrology from snow-covered catchments for water resources manage- ment. The snow cover is also a key link

  3. Wind-Driven Snow Buildup Using a Level Set Approach Tommy Hinks1

    E-Print Network [OSTI]

    Wind-Driven Snow Buildup Using a Level Set Approach Tommy Hinks1 and Ken Museth2 1University are achieved by tracing snow-carrying particles in a dynamic wind-field and on the surfaces of objects. Local of the scene complexity. Such techniques could be used to generate snow-covered scenes for movies as well

  4. 368 VOLUME 42J O U R N A L O F A P P L I E D M E T E O R O L O G Y 2003 American Meteorological Society

    E-Print Network [OSTI]

    ), with the substantial advantages over visible observations that the microwave observa- tions do not depend on the solar Microwave and Infrared Satellite Observations C. PRIGENT CNRS, LERMA, Observatoire de Paris, Paris, France F Microwave Imager observations for snow-covered land areas using a neural network inversion scheme

  5. Seasonality of soil CO2 efflux in a temperate forest: Biophysical effects of snowpack and spring freeze–thaw cycles

    SciTech Connect (OSTI)

    Wang, Chuankuan; Han, Yi; Chen, Jiquan; Wang, Xingchang; Zhang, Quanzhi; Bond-Lamberty, Benjamin

    2013-08-15

    Changes in characteristics of snowfall and spring freeze–thaw-cycle (FTC) events under the warming climate make it critical to understand biophysical controls on soil CO2 efflux (RS) in seasonally snow-covered ecosystems. We conducted a snow removal experiment and took year-round continuous automated measurements of RS, soil temperature (T5) and soil volumetric water content at the 5 cm depth (W5) with a half-hour interval in a Chinese temperate forest in 2010–2011. Our objectives were to: (1) develop statistical models to describe the seasonality of RS in this forest; (2) quantify the contribution of seasonal RS to the annual budget; (3) examine biophysical effects of snowpack on RS; and (4) test the hypothesis that an FTC-induced enhancement of RS is jointly driven by biological and physical processes.

  6. Crisis of the Chaotic Attractor of a Climate Model: A Transfer Operator Approach

    E-Print Network [OSTI]

    Alexis Tantet; Valerio Lucarini; Frank Lunkeit; Henk A. Dijkstra

    2015-07-08

    The destruction of a chaotic attractor leading to a rough change in the dynamics of a system as a control parameter is smoothly varied is studied. While bifurcations involving non-chaotic invariant sets, such as fixed points or periodic orbits, can be characterised by a Lyapunov exponent crossing the imaginary axis, little is known about the changes in a chaotic attractor during a crisis. The statistical physics framework, is particularly well suited for the study of global properties of chaotic systems. In particular, the semigroup of transfer operators governing the finite time evolution of probability distributions in phase space and its spectrum characterises both the relaxation rate of distributions to a statistical steady-state and the stability of this steady-state to perturbations. If critical slowing down indeed occurs in the approach to an attractor crisis, the gap in the spectrum (between the leading eigenvalue and the secondary ones) of the semigroup is expected to shrink. Here we use a high-dimensional, chaotic climate model system in which a transition from today's warm climate state to a snow-covered state occurs. This transition is associated with the destruction of a chaotic attractor as the solar constant is decreased. We show that critical slowing down develops in this model before the destruction of the chaotic attractor and that it can be observed from trajectories along the attractor. In addition, we demonstrate that the critical slowing down can be traced back to the shrinkage of the leading eigenvalues of coarse-grained approximations of the transfer operators and that these eigenvalues capture the fundamental features of the attractor crisis.

  7. Surface Albedo/BRDF Parameters (Terra/Aqua MODIS)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Trishchenko, Alexander

    Spatially and temporally complete surface spectral albedo/BRDF products over the ARM SGP area were generated using data from two Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on Terra and Aqua satellites. A landcover-based fitting (LBF) algorithm is developed to derive the BRDF model parameters and albedo product (Luo et al., 2004a). The approach employs a landcover map and multi-day clearsky composites of directional surface reflectance. The landcover map is derived from the Landsat TM 30-meter data set (Trishchenko et al., 2004a), and the surface reflectances are from MODIS 500m-resolution 8-day composite products (MOD09/MYD09). The MOD09/MYD09 data are re-arranged into 10-day intervals for compatibility with other satellite products, such as those from the NOVA/AVHRR and SPOT/VGT sensors. The LBF method increases the success rate of the BRDF fitting process and enables more accurate monitoring of surface temporal changes during periods of rapid spring vegetation green-up and autumn leaf-fall, as well as changes due to agricultural practices and snowcover variations (Luo et al., 2004b, Trishchenko et al., 2004b). Albedo/BRDF products for MODIS on Terra and MODIS on Aqua, as well as for Terra/Aqua combined dataset, are generated at 500m spatial resolution and every 10-day since March 2000 (Terra) and July 2002 (Aqua and combined), respectively. The purpose for the latter product is to obtain a more comprehensive dataset that takes advantages of multi-sensor observations (Trishchenko et al., 2002). To fill data gaps due to cloud presence, various interpolation procedures are applied based on a multi-year observation database and referring to results from other locations with similar landcover property. Special seasonal smoothing procedure is also applied to further remove outliers and artifacts in data series.

  8. Aerosol remote sensing in polar regions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tomasi, Claudio; Kokhanovsky, Alexander A.; Lupi, Angelo; Ritter, Christoph; Smirnov, Alexander; O'Neill, Norman T.; Stone, Robert S.; Holben, Brent N.; Nyeki, Stephan; Wehrli, Christoph; et al

    2015-01-01

    Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness ?(?) at visible and near-infrared wavelengths, from which best-fit values of Ångström's exponent ? were calculated. Analysing these data, the monthly mean values of ?(0.50 ?m) and ? and the relative frequency histograms of the daily mean values of both parameters were determined for winter–spring and summer–autumn in the Arctic and for austral summer in Antarctica. The Arctic and Antarctic covariance plots of the seasonal median values of ? versus ?(0.50 ?m) showed: (i)more »a considerable increase in ?(0.50 ?m) for the Arctic aerosol from summer to winter–spring, without marked changes in ?; and (ii) a marked increase in ?(0.50 ?m) passing from the Antarctic Plateau to coastal sites, whereas ? decreased considerably due to the larger fraction of sea-salt aerosol. Good agreement was found when comparing ground-based sun-photometer measurements of ?(?) and ? at Arctic and Antarctic coastal sites with Microtops measurements conducted during numerous AERONET/MAN cruises from 2006 to 2013 in three Arctic Ocean sectors and in coastal and off-shore regions of the Southern Atlantic, Pacific, and Indian Oceans, and the Antarctic Peninsula. Lidar measurements were also examined to characterise vertical profiles of the aerosol backscattering coefficient measured throughout the year at Ny-Ålesund. Satellite-based MODIS, MISR, and AATSR retrievals of ?(?) over large parts of the oceanic polar regions during spring and summer were in close agreement with ship-borne and coastal ground-based sun-photometer measurements. An overview of the chemical composition of mode particles is also presented, based on in-situ measurements at Arctic and Antarctic sites. Fourteen log-normal aerosol number size-distributions were defined to represent the average features of nuclei, accumulation and coarse mode particles for Arctic haze, summer background aerosol, Asian dust and boreal forest fire smoke, and for various background austral summer aerosol types at coastal and high-altitude Antarctic sites. The main columnar aerosol optical characteristics were determined for all 14 particle modes, based on in-situ measurements of the scattering and absorption coefficients. Diurnally averaged direct aerosol-induced radiative forcing and efficiency were calculated for a set of multimodal aerosol extinction models, using various Bidirectional Reflectance Distribution Function models over vegetation-covered, oceanic and snow-covered surfaces. These gave a reliable measure of the pronounced effects of aerosols on the radiation balance of the surface–atmosphere system over polar regions.« less

  9. Aerosol remote sensing in polar regions

    SciTech Connect (OSTI)

    Tomasi, Claudio; Kokhanovsky, Alexander A.; Lupi, Angelo; Ritter, Christoph; Smirnov, Alexander; O'Neill, Norman T.; Stone, Robert S.; Holben, Brent N.; Nyeki, Stephan; Mazzola, Mauro; Lanconelli, Christian; Vitale, Vito; Stebel, Kerstin; Aaltonen, Veijo; de Leeuw, Gerrit; Rodriguez, Edith; Herber, Andreas B.; Radionov, Vladimir F.; Zielinski, Tymon; Petelski, Tomasz; Sakerin, Sergey M.; Kabanov, Dmitry M.; Xue, Yong; Mei, Linlu; Istomina, Larysa; Wagener, Richard; McArthur, Bruce; Sobolewski, Piotr S.; Kivi, Rigel; Courcoux, Yann; Larouche, Pierre; Broccardo, Stephen; Piketh, Stuart J.

    2015-01-01

    Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness ?(?) at visible and near-infrared wavelengths, from which best-fit values of Ångström's exponent ? were calculated. Analysing these data, the monthly mean values of ?(0.50 ?m) and ? and the relative frequency histograms of the daily mean values of both parameters were determined for winter–spring and summer–autumn in the Arctic and for austral summer in Antarctica. The Arctic and Antarctic covariance plots of the seasonal median values of ? versus ?(0.50 ?m) showed: (i) a considerable increase in ?(0.50 ?m) for the Arctic aerosol from summer to winter–spring, without marked changes in ?; and (ii) a marked increase in ?(0.50 ?m) passing from the Antarctic Plateau to coastal sites, whereas ? decreased considerably due to the larger fraction of sea-salt aerosol. Good agreement was found when comparing ground-based sun-photometer measurements of ?(?) and ? at Arctic and Antarctic coastal sites with Microtops measurements conducted during numerous AERONET/MAN cruises from 2006 to 2013 in three Arctic Ocean sectors and in coastal and off-shore regions of the Southern Atlantic, Pacific, and Indian Oceans, and the Antarctic Peninsula. Lidar measurements were also examined to characterise vertical profiles of the aerosol backscattering coefficient measured throughout the year at Ny-Ålesund. Satellite-based MODIS, MISR, and AATSR retrievals of ?(?) over large parts of the oceanic polar regions during spring and summer were in close agreement with ship-borne and coastal ground-based sun-photometer measurements. An overview of the chemical composition of mode particles is also presented, based on in-situ measurements at Arctic and Antarctic sites. Fourteen log-normal aerosol number size-distributions were defined to represent the average features of nuclei, accumulation and coarse mode particles for Arctic haze, summer background aerosol, Asian dust and boreal forest fire smoke, and for various background austral summer aerosol types at coastal and high-altitude Antarctic sites. The main columnar aerosol optical characteristics were determined for all 14 particle modes, based on in-situ measurements of the scattering and absorption coefficients. Diurnally averaged direct aerosol-induced radiative forcing and efficiency were calculated for a set of multimodal aerosol extinction models, using various Bidirectional Reflectance Distribution Function models over vegetation-covered, oceanic and snow-covered surfaces. These gave a reliable measure of the pronounced effects of aerosols on the radiation balance of the surface–atmosphere system over polar regions.

  10. Sensitivity studies on the impacts of Tibetan Plateau snowpack pollution on the Asian hydrological cycle and monsoon climate

    SciTech Connect (OSTI)

    Qian, Yun; Flanner, M. G.; Leung, Lai-Yung R.; Wang, Weiguo

    2011-03-02

    The Tibetan Plateau (TP), the highest and largest plateau in the world, has long been identified to be critical in regulating the Asian monsoon climate and hydrological cycle. The snowpack and glaciers over the TP provide fresh water to billions of people in Asian countries, but the TP glaciers have been retreating extensively at a speed faster than any other part of the world. In this study a series of experiments with a global climate model are designed to simulate black carbon (BC) and dust in snow and their radiative forcing and to assess the relative impacts of anthropogenic CO2 and carbonaceous particles in the atmosphere and snow, respectively, on the snowpack over the TP, as well as their subsequent impacts on the Asian monsoon climate and hydrological cycle. Results show a large BC content in snow over the TP, especially the southern slope, with concentration larger than 100 µk/kg. Because of the high aerosol content in snow and large incident solar radiation in the low latitude and high elevation, the TP exhibits the largest surface radiative forcing induced by aerosols (e.g. BC, Dust) in snow compared to other snow-covered regions in the world. The aerosol-induced snow albedo perturbations generate surface radiative forcing of 5-25 W m-2 during spring, with a maximum in April or May. BC-in-snow increases the surface air temperature by around 1.0oC averaged over the TP and reduces snowpack over the TP more than that induced by pre-industrial to present CO2 increase and carbonaceous particles in the atmosphere during spring. As a result, runoff increases during late winter and early spring but decreases during late spring and early summer (i.e. a trend toward earlier melt dates). The snowmelt efficacy, defined as the snowpack reduction per unit degree of warming induced by the forcing agent, is 1-4 times larger for BC-in-snow than CO2 increase during April-July, indicating that BC-in-snow more efficiently accelerates snowmelt because the increased net solar radiation induced by reduced albedo melts the snow more efficiently than snow melt due to warming in the air. The TP also influences the South (SAM) and East (EAM) Asian monsoon through its dynamical and thermal forcing. During boreal spring, aerosols are transported by the southwesterly and reach the higher altitude and/or deposited in the snowpack over the TP. While BC and OM in the atmosphere directly absorb sunlight and warm the air, the darkened snow surface polluted by BC absorbs more solar radiation and increases the skin temperature, which warms the air above by the increased sensible heat flux over the TP. Both effects enhance the upward motion of air and spur deep convection along the TP during pre-monsoon season, resulting in earlier onset of the SAM and increase of moisture, cloudiness and convective precipitation over northern India. BC-in-snow has a more significant impact on the EAM in July than CO2 increase and carbonaceous particles in the atmosphere. Contributed by the significant increase of both sensible heat flux associated with the warm skin temperature and latent heat flux associated with increased soil moisture with long memory, the role of the TP as a heat pump is elevated from spring through summer as the land-sea thermal contrast increases to strengthen the EAM. As a result, both southern China and northern China become wetter, but central China (i.e. Yangtze River Basin) becomes drier - a near zonal anomaly pattern that is consistent with the dominant mode of precipitation variability in East Asia. ?