نتایج جستجو برای: snow cover

تعداد نتایج: 124383  

2007
David A. Robinson

Output from satellite-borne passive microwave sensors has increasingly been recognized as an important means of monitoring snow cover. However, employing a single global algorithm t o extract a snow signal from multichannel microwave data does not accurately monitor snow across all landscapes. One such region where difficulties occur is the Tibetan Plateau, where global algorithms overestimate ...

2014
Barry G. Robinson Alastair Franke Andrew E. Derocher

Climate change is occurring more rapidly in the Arctic than other places in the world, which is likely to alter the distribution and abundance of migratory birds breeding there. A warming climate can provide benefits to birds by decreasing spring snow cover, but increases in the frequency of summer rainstorms, another product of climate change, may reduce foraging opportunities for insectivorou...

2010
G. Venkataraman

The full polarimetric L-band ALOS-PALSAR data of snow cover area in Himalayan region have been analyzed based on various component scattering mechanism models and all model results are compared. Various polarimetric descriptors (Viz. degree of polarization, co-polarization coherence, total power, phase difference, polarization fraction) are also applied for snow discrimination. Based on these t...

2003
GEORGE RIGGS DOROTHY K. HALL

A challenging problem in snow mapping is the discrimination of snow from clouds. Snow and clouds often have similar spectral reflectance features across the spectrum and may have similar temperatures making discrimination difficult. Data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the NASA Earth Observing System (EOS) Terra spacecraft, is used to generate many geophys...

2015
Y. Yi J. S. Kimball M. A. Rawlins M. Moghaddam E. S. Euskirchen

Northern Hemisphere permafrost affected land areas contain about twice as much carbon as the global atmosphere. This vast carbon pool is vulnerable to accelerated losses through mobilization and decomposition under projected global warming. Satellite data records spanning the past 3 decades indicate widespread reductions (∼ 0.8– 1.3 days decade) in the mean annual snow cover extent and frozen-s...

2017
Y. Yi John S. Kimball Michael A. Rawlins Mahta Moghaddam E. S. Euskirchen

Northern Hemisphere permafrost affected land ar­ eas contain abont twice as mnch carbon as the global at­ mosphere. This vast carbon pool is vnlnerable to acceler­ ated losses throngh mobilization and decomposition nnder projected global warming. Satellite data records sparming the past 3 decades indicate widespread redactions ( ~ 0.81.3 days decade “ ̂ ) in the mean aimnal snow cover extent and...

Journal: :Scanning 2006
James Foster Richard Kelly Albert Rango Richard Armstrong Eric F Erbe Christopher Pooley William P Wergin

This study, which uses low-temperature scanning electron microscopy (LTSEM), systematically sampled and characterized snow crystals that were collected from three unique classes of snow cover: prairie, taiga, and alpine. These classes, which were defined in previous field studies, result from exposure to unique climatic variables relating to wind, precipitation, and air temperature. Snow sample...

Journal: :Environmental entomology 2009
Ankush Joshi Denise L Olson Donald R Carey

We evaluated the effects of snow cover and debris cover on overwintering success of Aphthona from 2001 to 2004 in southeast North Dakota. Chill degree-days, soil temperature, and duration of soil temperatures were monitored in field plots. Emergence of Aphthona from soil cores collected in October and held in the laboratory under simulated winter conditions did not differ across treatments. Fie...

2008
Steven C. Hardiman Paul J. Kushner Judah Cohen

[1] The ability of general circulation models (GCMs) to reproduce the observed strong correlations of Eurasian snow extent in the fall to wave activity and Northern Annular Mode anomalies in the following winter is studied. The observed correlations have been hypothesized to involve two parts: a Rossby wave pulse generated in the troposphere in response to snow-forced surface cooling and a coup...

Journal: :Remote Sensing 2017
David K. Swanson

In cold-limited arctic environments, the duration and timing of the snow cover and the vegetation green season have major ecological implications. I monitored the phenology of snow cover and greenness using MODIS Terra satellite data for the years 2000 to 2016 in the 5 National Parks of northern Alaska, USA. Mann-Kendall trend tests showed that the end of the continuous snow season and midpoint...

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