Estimation of snow water equivalent over first-year sea ice using AMSR-E and surface observations

Abstract. Seven gridded northern hemisphere snow water equivalent (SWE) products were evaluated as part of the European Space Agency (ESA) Satellite Snow Product Inter-comparison and Evaluation Exercise (SnowPEx). Three categories of datasets were assessed: (1) those utilizing some form of reanalysis (the NASA Global Land Data Assimilation System version 2 – GLDAS; the European Centre for Medium-Range Forecasts interim land surface reanalysis – ERA-land; the NASA Modern-Era Retrospective Analysis for Research and Applications – MERRA; the Crocus snow model driven by ERA-Interim meteorology – Crocus); (2) passive microwave remote sensing combined with daily surface snow depth observations (ESA GlobSnow v2.0); and (3) standalone passive microwave retrievals (NASA AMSR-E historical and operational algorithms) which do not utilize surface snow observations. Evaluation included comparisons against independent surface observations from Russia, Finland, and Canada, and calculation of spatial and temporal correlations in SWE anomalies. The standalone passive microwave SWE products (AMSR-E historical and operational SWE algorithms) exhibit low spatial and temporal correlations to other products, and RMSE nearly double the best performing product. Constraining passive microwave retrievals with surface observations (GlobSnow) provides comparable performance to the reanalysis-based products; RMSEs over Finland and Russia for all but the AMSR-E products is ~50 mm or less. Using a four-dataset ensemble that excluded the standalone passive microwave products reduced the RMSE by 10 mm (20%) and increased the correlation by 0.1; ensembles that contain Crocus and/or MERRA perform better than those that do not. The observed RMSE of the best performing datasets is still at the margins of acceptable uncertainty for scientific and operational requirements; only through combined and integrated improvements in remote sensing, modeling, and observations will real progress in SWE product development be achieved.

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Modelling the water budget and the riverflows of the Maritsa basin in Bulgaria

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-4-475-2007 ◽

2007 ◽

Vol 4 (2) ◽

pp. 475-521 ◽

Cited By ~ 3

Author(s):

E. Artinyan ◽

F. Habets ◽

J. Noilhan ◽

E. Ledoux ◽

D. Dimitrov ◽

...

Keyword(s):

Water Budget ◽

Snow Water Equivalent ◽

Water Cycle ◽

Slow Component ◽

First Year ◽

Transfer Model ◽

Distributed Hydrological Model ◽

Snow Water ◽

High Level ◽

The Impact

Abstract. A soil-vegetation-atmosphere transfer model coupled with a macroscale distributed hydrological model was used in order to simulate the water cycle for a large region in Bulgaria. To do so, an atmospheric forcing was built for two hydrological years (1 October 1995 to 30 September 1997), at an eight km resolution. It was based on the data available at the National Institute of Meteorology and Hydrology (NIMH) of Bulgaria. Atmospheric parameters were carefully checked and interpolated with a high level of detail in space and time (3-h step). Comparing computed Penman evapotranspiration versus observed pan evaporation validated the quality of the implemented forcing. The impact of the human activities on the rivers (especially hydropower or irrigation) was taken into account. Some improvements of the hydrometeorological model were made: for better simulation of summer riverflow, two additional reservoirs were added to simulate the slow component of the runoff. Those reservoirs were calibrated using the observed data of the 1st year, while the 2nd year was used for validation. 56 hydrologic stations and 12 dams were used for the model calibration while 41 rivergages were used for the validation of the model. The results compare well with the daily-observed discharges, with good results obtained over more than 25% of the rivergages. The simulated snow depth was compared to daily measurements at 174 stations and the evolution of the snow water equivalent was validated at 5 sites. The process of melting and refreezing of snow was found to be important on this region. The comparison of the normalized values of simulated versus measured soil moisture showed good correlation. The surface water budget shows large spatial variations due to the elevation influence on the precipitations, soil properties and vegetation variability. An inter annual difference was observed in the water cycle as the first year was more influenced by Mediterranean climate, while the second year was characterised by continental influence. Energy budget shows a dominating sensible heat component in summer, due to the fact that the water stress limits the evaporation. This study is a first step for the implementation of an operational hydrometeorological model that could be used for real time monitoring and forecast the water budget and the riverflow of Bulgaria.

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Validation of a snow water equivalence algorithm over landfast first-year sea ice using RADARSAT-1

IEEE International Geoscience and Remote Sensing Symposium ◽

10.1109/igarss.2002.1024997 ◽

2003 ◽

Author(s):

J.J. Yackel ◽

D.G. Barber

Keyword(s):

Sea Ice ◽

First Year ◽

Snow Water

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Cryosphere Applications

Polarimetric Synthetic Aperture Radar - Remote Sensing and Digital Image Processing ◽

10.1007/978-3-030-56504-6_4 ◽

2020 ◽

pp. 179-213

Author(s):

I. Hajnsek ◽

G. Parrella ◽

A. Marino ◽

T. Eltoft ◽

M. Necsoiu ◽

...

Keyword(s):

High Resolution ◽

Sea Ice ◽

Synthetic Aperture Radar ◽

Snow Water Equivalent ◽

Real Data ◽

Near Surface ◽

Ice Volume ◽

Snow Water ◽

Surface Ice

AbstractSynthetic aperture radar (SAR) provides large coverage and high resolution, and it has been proven to be sensitive to both surface and near-surface features related to accumulation, ablation, and metamorphism of snow and firn. Exploiting this sensitivity, SAR polarimetry and polarimetric interferometry found application to land ice for instance for the estimation of wave extinction (which relates to sub surface ice volume structure) and for the estimation of snow water equivalent (which relates to snow density and depth). After presenting these applications, the Chapter proceeds by reviewing applications of SAR polarimetry to sea ice for the classification of different ice types, the estimation of thickness, and the characterisation of its surface. Finally, an application to the characterisation of permafrost regions is considered. For each application, the used (model-based) decomposition and polarimetric parameters are critically described, and real data results from relevant airborne campaigns and space borne acquisitions are reported.

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Modelling the water budget and the riverflows of the Maritsa basin in Bulgaria

Hydrology and Earth System Sciences ◽

10.5194/hess-12-21-2008 ◽

2008 ◽

Vol 12 (1) ◽

pp. 21-37 ◽

Cited By ~ 19

Author(s):

E. Artinyan ◽

F. Habets ◽

J. Noilhan ◽

E. Ledoux ◽

D. Dimitrov ◽

...

Keyword(s):

Water Budget ◽

River Flow ◽

Snow Water Equivalent ◽

Water Cycle ◽

Slow Component ◽

First Year ◽

Transfer Model ◽

Distributed Hydrological Model ◽

Snow Water ◽

The Impact

Abstract. A soil-vegetation-atmosphere transfer model coupled with a macroscale distributed hydrological model was used to simulate the water cycle for a large region in Bulgaria. To do so, an atmospheric forcing was built for two hydrological years (1 October 1995 to 30 September 1997), at an eight km resolution. The impact of the human activities on the rivers (especially hydropower or irrigation) was taken into account. An improvement of the hydrometeorological model was made: for better simulation of summer riverflow, two additional reservoirs were added to simulate the slow component of the runoff. Those reservoirs were calibrated using the observed data of the 1st year, while the 2nd year was used for validation. 56 hydrologic stations and 12 dams were used for the model calibration while 41 river gauges were used for the validation of the model. The results compare well with the daily-observed discharges, with good results obtained over more than 25% of the river gauges. The simulated snow depth was compared to daily measurements at 174 stations and the evolution of the snow water equivalent was validated at 5 sites. The process of melting and refreezing of snow was found to be important in this region. The comparison of the normalized values of simulated versus measured soil moisture showed good correlation. The surface water budget shows large spatial variations due to the elevation influence on the precipitation, soil properties and vegetation variability. An inter-annual difference was observed in the water cycle as the first year was more influenced by Mediterranean climate, while the second year was characterised by continental influence. The energy budget shows a dominating sensible heat component in summer, due to the fact that the water stress limits the evaporation. This study is a first step for the implementation of an operational hydrometeorological model that could be used for real time monitoring and forecasting of water budget components and river flow in Bulgaria.

Download Full-text