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Active-Layer Soil Moisture Content Regional Variations in Alaska and Russia by Ground-Based and Satellite-Based Methods, 2002 through 2014

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http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53322#.VL3BWizQrzE

ABSTRACT
Soil moisture is a vital physical parameter of the active-layer in permafrost environments, and associated biological and geophysical processes operative at the microscopic to hemispheric spatial scales and at hourly to multi-decadal time scales. While in-situ measurements can give the highest quality of information on a site-specific basis, the vast permafrost terrains of North America and Eurasia require space-based techniques for assessments of cause and effect and long-term changes and impacts from the changes of permafrost and the active-layer. Satellite-based 6.925 and 10.65 GHz sensor algorithmic retrievals of soil moisture by Advanced Microwave Scanning Radiometer-Earth Observation System (AMSR-E) onboard NASA-Aqua and follow-on AMSR2 onboard JAXA-Global Change Observation Mission—Water-1 are ongoing since July 2002. Accurate land-surface temperature and vegetation parameters are critical to the success of passive microwave algorithmic retrieval schemes. Strategically located soil moisture measurements are needed for spatial and temporal co-location evaluation and validation of the space-based algorithmic estimates. We compare on a daily basis ground-based (subsurface-probe) 50- and 70-MHz radio-frequency soil moisture measurements with NASA- and JAXA-algorithmic retrieval passive microwave retrievals. We find improvements in performance of the JAXA-algorithm (AMSR-E reprocessed and AMSR2 ongoing) relative to the earlier NASA-algorithm version. In the boreal forest regions, accurate land-surface temperatures and vegetation parameters are still needed for algorithmic retrieval success. Over the period of AMSR-E retrievals, we find evidence of at the high northern latitudes of growing terrestrial radio-frequency interference in the 10.65 GHz channel soil moisture content. This is an important error source for satellite-based active and passive microwave remote sensing soil moisture retrievals in Arctic regions that must be addressed.
 

ABSTRACT
Soil moisture is a vital physical parameter of the active-layer in permafrost environments, and associated biological and geophysical processes operative at the microscopic to hemispheric spatial scales and at hourly to multi-decadal time scales. While in-situ measurements can give the highest quality of information on a site-specific basis, the vast permafrost terrains of North America and Eurasia require space-based techniques for assessments of cause and effect and long-term changes and impacts from the changes of permafrost and the active-layer. Satellite-based 6.925 and 10.65 GHz sensor algorithmic retrievals of soil moisture by Advanced Microwave Scanning Radiometer-Earth Observation System (AMSR-E) onboard NASA-Aqua and follow-on AMSR2 onboard JAXA-Global Change Observation Mission—Water-1 are ongoing since July 2002. Accurate land-surface temperature and vegetation parameters are critical to the success of passive microwave algorithmic retrieval schemes. Strategically located soil moisture measurements are needed for spatial and temporal co-location evaluation and validation of the space-based algorithmic estimates. We compare on a daily basis ground-based (subsurface-probe) 50- and 70-MHz radio-frequency soil moisture measurements with NASA- and JAXA-algorithmic retrieval passive microwave retrievals. We find improvements in performance of the JAXA-algorithm (AMSR-E reprocessed and AMSR2 ongoing) relative to the earlier NASA-algorithm version. In the boreal forest regions, accurate land-surface temperatures and vegetation parameters are still needed for algorithmic retrieval success. Over the period of AMSR-E retrievals, we find evidence of at the high northern latitudes of growing terrestrial radio-frequency interference in the 10.65 GHz channel soil moisture content. This is an important error source for satellite-based active and passive microwave remote sensing soil moisture retrievals in Arctic regions that must be addressed.
 
Cite this paper
Muskett, R. , Romanovsky, V. , Cable, W. and Kholodov, A. (2015) Active-Layer Soil Moisture Content Regional Variations in Alaska and Russia by Ground-Based and Satellite-Based Methods, 2002 through 2014. International Journal of Geosciences, 6, 12-41. doi: 10.4236/ijg.2015.61002.
 
References
[1]Hillel, D. (1980) Fundamentals of Soil Physics. Academic Press, New York.
 
[2]Delworth, T. and Manabe, S. (1988) The Influence of Potential Evaporation on the Variability of Simulated Soil Wetness and Climate. Journal of Climate, 13, 2900-2922.
 
[3]Chang, J.T. and Wetzel, P.J. (1991) Effects of Spatial Variations of Soil Moisture and Vegetation on the Evolution of a Prestorm Environment: A Numerical Case Study. Monthly Weather Review, 119, 1368-1390. http://dx.doi.org/10.1175/1520-0493(1991)119<1368:EOSVOS>2.0.CO;2
 
[4]Raich, J.W. and Schlesinger, W.H. (1992) The Global Carbon Dioxide Flux in Soil Respiration and Its Relationship to Vegetation and Climate. Tellus B, 44, 81-99.
http://dx.doi.org/10.1034/j.1600-0889.1992.t01-1-00001.x
 
[5]Schar, C., Luthi, D., Beyerle, U. and Heise, E. (1999) The Soil-Precipitation Feedback: A Process Study with a Regional Climate Model. Journal of Climate, 12, 722-741.
http://dx.doi.org/10.1175/1520-0442(1999)012<0722:TSPFAP>2.0.CO;2
 
[6]Jackson, R.D. (1973) Diurnal Soil-Water Content Changes during Drying, Field Solar Water Regime. Soil Science Society of America, 5, 37-56.
 
[7]Blanchard, B.J. and Chang, A.T.C. (1983) Estimation of Soil Moisture from SEASAT SAR Data. Journal of the American Water Resources Association, 19, 803-810.
http://dx.doi.org/10.1111/j.1752-1688.1983.tb02803.x                                                         eww150120lx
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