AUTHOR=Shao Changliang , Guo Yakai , Cao Yunchang , Wang Jiao 

TITLE=A high-resolution soil moisture content analysis product in Jing-Jin-Ji using the successive correction method

JOURNAL=Frontiers in Earth Science

VOLUME=Volume 10 - 2022

YEAR=2023

URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2022.1037065

DOI=10.3389/feart.2022.1037065

ISSN=2296-6463

ABSTRACT=Two soil moisture content analysis products with a spatial resolution of 0.0625° and a temporal resolution of 1 hour from October 1st, 2015 to October 1st, 2021 in the JingJinJi area have been developed and evaluated. By using a quality control (QC) scheme based on the biweight method and a successive correction method (SCM) with different weighting functions introduced from the Cressman and/or Barnes method, the soil moisture collected from China land data assimilation system version 2.0 (CLDAS V2.0) taken as the background data, two soil analysis products with hourly station soil observations induced have been conducted and further compared with in-situ observations and satellite products. Results show that with the biweight method, the outliers of soil moisture can be identified, and the number of those is less than 10% of the actual reported samples. The analysis product with the Cressman weighting function is more accurate than with the Barnes, as the root mean square error can reduce by 30% to 0.06, while the correlation coefficient can increase by 73% to 0.59, compared to Ctr. These results indicate that the Cressman product is a useful and promising soil moisture data set. The proposed Cressman method is computationally simple and efficient, so the product can be easily updated to keep pace with tremendous increases in the volume of soil moisture data. The methods used here for QC, SCM, and comparison could help evaluate and improve land surface models and their soil moisture products.