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

TitleActive-Layer Soil Moisture Content Regional Variations in Alaska and Russia by Ground-Based and Satellite-Based Methods, 2002 through 2014
Publication TypeJournal Article
Year of Publication2015
AuthorsMuskett, Reginald R., Romanovsky Vladimir E., Cable William L., and Kholodov Alexander L.
JournalInternational Journal of Geosciences
Volume06
Issue01
Pagination12 - 41
Date PublishedJan-01-2015
ISSN2156-8359
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. Satellitebased
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 followon
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 (subsurfaceprobe)
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.

URLhttp://dx.doi.org/10.4236/ijg.2015.61002
DOI10.4236/ijg.2015.61002
Short TitleIJG