The effect of subarctic woodland vegetation on the radiation balance of a melting snow cover

1986 ◽  
Vol 34 (3-4) ◽  
pp. 297-310 ◽  
Author(s):  
Peter Lafleur ◽  
P. Adams
Keyword(s):  
Snow Cover ◽  
Radiation Balance ◽  
Melting Snow

Snow Cover and Melting Snow from ERTS Imagery

1974 ◽  
Vol 28 (2) ◽  
pp. 128-134 ◽  
Author(s):  
Douglas L. Golding
Keyword(s):  
Thin Film ◽  
Snow Cover ◽  
Return Period ◽  
Infrared Radiation ◽  
Cloud Cover ◽  
Near Infrared ◽  
Infrared Imagery ◽  
Transient Phenomena ◽  
Melting Snow ◽  
Mountain Watersheds

To evaluate the usefulness of ERTS imagery for obtaining information on snow cover for small mountain watersheds, two specific objectives were set: (1) to determine if snowpack ablation due to chinooks can be detected on ERTS imagery, and (2) to determine if melting snow can be distinguished from snow that has not yet begun to melt. The length of ERTS return period and the frequency of cloud cover over the mountains in winter combined to make the ERTS system almost useless in studying transient phenomena of short-return period such as the chinook. Melting snow could be distinguished from snow that had not reached melting temperature. The latter appeared light toned on both visible and near-infrared imagery because of its high reflectivity in these portions of the spectrum. Melting snow, however, appeared dark on near-infrared imagery because much of the incident infrared radiation is absorbed by the thin film of water on the surface of the melting snow.

scholarly journals Construction and Application of Snow-melting Runoff Model Based on MODIS Satellite Data

2018 ◽  
Vol 246 ◽  
pp. 01100
Author(s):  
Jian Chen ◽  
Kai Shu ◽  
Jianping Wang ◽  
Chunhong Li ◽  
Feng Wang
Keyword(s):  
Snow Cover ◽  
Real Time ◽  
Relative Error ◽  
Satellite Data ◽  
Snow Melting ◽  
Melting Snow ◽  
Kaidu River ◽  
Basin Area ◽  
Runoff Model ◽  
Operation Scheduling

It is very complicated to accurately describe the process of watershed runoff yield and concentration, which is comprehensive influenced by snow covering, temperature, precipitation, the wetland areas and other factors in the basin of Kaidu River upstream of Chahanwusu Reservoir. It is that real-time updating MODIS satellite snow cover products MOD10A2 and 30 meters by 30 meters of DEM data are applied to calculate elevation~ basin area ~ snow covering area curve, virtual free reservoir is put forward to simulate the wetlands concentration of upstream Bayinbuluke and sahentuohai hydrological gauge stations and mixed melting snow and runoff yield under saturated storage concentration model is constructed in this article. The model behaved good to simulate the Inflow process of Chahanwusu Reservoir, and the relative error between simulated and measured processes reached 83.79%, the deterministic coefficient reaches about 0.8, which is better supporting Chahanwusu Reservoir’s operation scheduling and dispatch decision.

Global Snow Cover Extent Mapping Using Sentinel-1

2020 ◽  
Author(s):  
Ya-Lun Tsai ◽  
Soner Uereyen ◽  
Andreas Dietz ◽  
Claudia Kuenzer ◽  
Natascha Oppelt
Keyword(s):  
Snow Cover ◽  
Low Cost ◽  
Global Radiation ◽  
Radiation Balance ◽  
Human Society ◽  
Vegetation Growth ◽  
Winter Tourism ◽  
Snow Cover Extent ◽  
Near Future

<p>Seasonal snow cover extent (SCE) is a critical component not only for the global radiation balance and climatic behavior but also for water availability of mountainous and arid regions, vegetation growth, permafrost, and winter tourism. However, due to the effects of the global warming, SCE has been observed to behave in much more irregular and extreme patterns in both temporal and spatial aspects. Therefore, a continuous SCE monitoring strategy is necessary to understand the effect of climate change on the cryosphere and to assess the corresponding impacts on human society and the environment. Nevertheless, although conventional optical sensor-based sensing approaches are mature, they suffer from cloud coverage and illumination dependency. Consequently, spaceborne Synthetic Aperture Radar (SAR) provides a pragmatic solution for achieving all-weather and day-and-night monitoring at low cost, especially after the launch of the Sentinel-1 constellation. </p><p>In the present study, we propose a new global SCE mapping approach, which utilizes dual-polarization intensity-composed bands, polarimetric H/A/α decomposition information, topographical factors, and a land cover layer to detect the SCE. By including not only amplitude but also phase information, we overcome the limitations of previous studies, which can only map wet SCE. Additionally, a layer containing the misclassification probability is provided as well for measuring the uncertainty. Based on the validation with in-situ stations and optical imagery, around 85% accuracy of the classification is ensured. Consequently, by implementing the proposed method globally, we can provide a novel way to map high resolution (20 m) and cloud-free SCE even under cloud covered/night conditions. Preparations to combine this product with the optical-based DLR Global SnowPack are already ongoing, offering the opportunity to provide a daily snow mapping service in the near future which is totally independent from clouds or polar darkness.</p>

scholarly journals Temporal and Spatial Changes in Snow Cover and the Corresponding Radiative Forcing Analysis in Siberia from the 1970s to the 2010s

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Lingxue Yu ◽  
Tingxiang Liu ◽  
Shuwen Zhang
Keyword(s):  
Snow Cover ◽  
Vegetation Cover ◽  
Radiative Forcing ◽  
Global Climate ◽  
Regional Scale ◽  
Surface Radiation ◽  
Radiation Balance ◽  
Spatial Changes ◽  
Long Time ◽  
Temporal And Spatial

In the context of global climate change, the extent of snow cover in Siberia has significantly decreased since the 1970s, especially in spring. The changes of snow cover at middle and high latitudes have significant impacts on the meteorological and hydrological processes because the snow cover can affect the surface energy, water balance, and the development of the atmospheric boundary layer. In this paper, the temporal and spatial changes in snow cover were firstly estimated based on a long time series of remote sensing snow cover data, both showing a decreased trend. Based on this, we estimated the radiative forcing caused by the snow cover changes from the 1970s to the 2010s and compared it with the radiative forcing caused by the vegetation cover changes over the same time period in Siberia, indicating that the snow cover changes in Siberia can accelerate climate warming and the vegetation cover changes here have the opposite effect. Furthermore, the snow cover changes may play a more important role than the vegetation cover changes in regulating the surface radiation balance in Siberia on the regional scale.

scholarly journals Zoning of erosion potential of water accumulated in snow cover based on climatological data analysis

2009 ◽  
Vol 57 (5) ◽  
pp. 271-278 ◽  
Author(s):  
Jana Smolíková ◽  
Hana Pokladníková ◽  
František Toman
Keyword(s):  
Snow Cover ◽  
Suspended Sediments ◽  
Climatic Conditions ◽  
Cold Period ◽  
Soil Freezing ◽  
Water Runoff ◽  
Melting Snow ◽  
Local Character ◽  
Area Of Interest ◽  
Torrential Rainfall

Melting of snow in winter and early spring often causes soil erosion. The results of erosion studies show that the runoff generated in the cold period can cause more intensive erosion than in the warm half year. By analysis of the monthly catchment of suspended sediments, it was found maximum of suspended sediments in the spring likely as effect of the spring melting of snow. Erosion caused by water from melting snow in our conditions does not reach the same intensity as the erosion caused by torrential rainfall. However, the torrential rainfall has only a local character, while the spring melting of snow usually affects larger territory. Erosive potential of water stored in snow cover can be established on the basis of the quantity of water resulting from melting snow and the speed of melting snow. Erosion caused by melting snow is given by quantity and the maximum speed of water runoff, which may be enhanced by rainfall, occurring in parallel with the snow melting. The total soil loss due to melting snow is also influenced by other factors: soil moisture, which affects the size of infiltration, soil freezing, the topography, the protective effect of vegetation, soil erodibility and implemented erosion control measures.The work analyzed erosive potential of snow cover during the cold period 1981/82 to 2007/2008 for the part of the Czech Republic, which falls within the scope of the Brno branch of the Czech Hy­dro­me­teo­ro­lo­gi­cal Institute (CHMI). For zoning of erosive potential of snow cover in the area of interest 22 climatological stations has been chosen (with regard to their equitable representation in different altitudes and different climatic conditions).The work brings erosive potential determination of water stored in snow cover. Its size corresponds to the altitude and climatic conditions represented by climatic region (according to Estimated Ecological Pedological Unit – EPEU) of investigational sites. Closeness of the relationship, expressed as a coefficient of correlation is 0.794, respectively 0.844. By the GIS interpolation on the basis of altitude a map of the erosive potential of the water stored in snow cover for the field of interest was processed.

scholarly journals Variability of the Surface Energy Balance in Permafrost Underlain Boreal Forest

2020 ◽  
Author(s):  
Simone Maria Stuenzi ◽  
Julia Boike ◽  
William Cable ◽  
Ulrike Herzschuh ◽  
Stefan Kruse ◽  
...  
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Boreal Forest ◽  
Snow Cover ◽  
Forest Cover ◽  
Surface Energy Balance ◽  
Surface Model ◽  
Radiation Balance ◽  
Near Surface ◽  
Strong Control

Abstract. Boreal forests in permafrost regions make up around one-third of the global forest cover and are an essential component of regional and global climate patterns. Further, climatic change can trigger extensive ecosystem shifts such as the partial disappearance of near surface permafrost or changes to the vegetation structure and composition. Therefore, our aim is to understand how the interactions between the vegetation, permafrost, and the atmosphere stabilize the forests and the underlying permafrost. Existing model set-ups are often static or are not able to capture important processes such as the vertical structure or the leaf physiological properties. There is a need for a physically based model with a robust radiative transfer scheme through the canopy. A one-dimensional land surface model (CryoGrid) is adapted for the application in vegetated areas by coupling a multilayer canopy model (CLM-ml v0) and is used to reproduce the energy transfer and thermal regime at a study site (N 63.18946, E 118.19596) in mixed boreal forest in Eastern Siberia. We have in-situ soil temperature and radiation measurements, to evaluate the model and demonstrate the capabilities of a coupled multilayer forest-permafrost model to investigate the vertical exchange of radiation, heat, and water. We find that the forests exert a strong control on the thermal state of permafrost through changing the radiation balance and snow cover phenology. The forest cover alters the surface energy balance by inhibiting over 90 % of the solar radiation and suppressing turbulent heat fluxes. Additionally, our simulations reveal a surplus in longwave radiation trapped below the canopy, similar to a greenhouse, which leads to a comparable magnitude in storage heat flux to that simulated at the grassland site. Further, the end of season snow cover is three times greater at the forest site and the onset of the snow melting processes are delayed.

The permeability of a melting snow cover

1982 ◽  
Vol 18 (4) ◽  
pp. 904-908 ◽  
Author(s):  
S. C. Colbeck ◽  
Eric A. Anderson
Keyword(s):  
Snow Cover ◽  
Melting Snow

scholarly journals Modeling arctic snow distribution and melt at the 1 km grid scale*

2004 ◽  
Vol 35 (4-5) ◽  
pp. 295-307 ◽  
Author(s):  
Ming-ko Woo ◽  
Kathy L. Young
Keyword(s):  
Snow Cover ◽  
Snow Water Equivalent ◽  
Base Station ◽  
Snow Accumulation ◽  
The Arctic ◽  
Radiation Balance ◽  
Target Area ◽  
Snow Distribution ◽  
Terrain Units ◽  
Energy Balance Approach

Snow accumulation, re-distribution and melt are important hydrological considerations in the Arctic. This study presents a model of the late-winter snow cover and the ensuing snowmelt in a High Arctic environment at a scale of 1 km. Indexing is used to spread the snow data from a lowland weather station to various terrain units over a 16×13 km2 target area east of Resolute, Cornwallis Island, Canada. Meteorological variables measured at this base station are spatially extended by field derived empirical relationships for the computation of melt at various terrain units using the energy balance approach. These melt rates are weighted by the fractional coverage of various terrain unit within each 1×1 km2 cell. The snow distribution pattern is obtained daily and model performance was tested by comparing observed and computed dates of melt and the radiation balance over snow. The simulated snow pattern compared favourably with the snow cover imaged by LANDSAT. Daily changes in the probability distribution of snow water equivalent over the target area was examined and snow depletion curves were derived. They describe sub-grid variability over an area and our results point to several assumptions that should be scrutinized in sub-grid parameterization of snow distribution.

The Role of Turbulent Heat Fluxes in the Energy Balance of High Alpine Snow Cover

1994 ◽  
Vol 25 (1-2) ◽  
pp. 25-38 ◽  
Author(s):  
C. Plüss ◽  
R. Mazzoni
Keyword(s):  
Energy Balance ◽  
Snow Cover ◽  
Correlation Method ◽  
Heat Fluxes ◽  
Eddy Correlation ◽  
Turbulent Heat ◽  
Net Radiation ◽  
Melting Snow ◽  
Measuring Period ◽  
Turbulent Heat Fluxes

Energy balance measurements over a seasonal snow cover were performed near Davos, Switzerland at 2,540 m a.s.l. The energy fluxes were studied over dry and melting snow covers. The beginning of snowmelt clearly coincides with the beginning of positive daily sums of net radiation. During snowmelt, net radiation is the dominant energy source. Latent and sensible heat fluxes do not show a significant seasonal change and remain slight over most of the measuring period. This minor contribution of the turbulent heat fluxes can be attributed to generally low wind speeds in this inner alpine region and to frequent inversions over the melting snow cover. In a changing climate the turbulent heat fluxes could become increasingly important in the energy balance. Therefore, evaluations of the turbulent heat fluxes from profile measurements and the eddy correlation method are compared with simple approximations commonly used in snowmelt models. The conditions under which these approximations can be used for routine discharge forecasts are identified.

The Radiation Balance of Melting Snow in Open Boreal Forest

1981 ◽  
Vol 13 (3) ◽  
pp. 287 ◽  
Author(s):  
D. E. Petzold
Keyword(s):  
Boreal Forest ◽  
Radiation Balance ◽  
Melting Snow
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