Evaluation of the European Space Agency Climate Change Initiative Soil Moisture Product over China Using Variance Reduction Factor |
| |
| Authors: | Xiaoji Shen Ru An Jonathan Arthur Quaye‐Ballard Ling Zhang Zhe Wang |
| |
| Affiliation: | 1. School of Earth Science and Engineering, Hohai University, Nanjing, China;2. Department of Geomatic Engineering, Faculty of Civil and Geo Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana |
| |
| Abstract: | In this study, we evaluated the European Space Agency Climate Change Initiative soil moisture product v02.1 (ESA CCI SM v02.1) using in situ observations collected at 547 stations in China from 1991 to 2013. A conventional validation was first conducted, and the triple collocation errors of ESA CCI SM and the European Centre for Medium Range Weather Forecasting reanalysis data were approximately 0.053 and 0.050 m3/m3, respectively. To obtain more reliable validation results, the average soil moisture of the in situ observations per ESA CCI SM pixel was also used as the validation sites. Variance reduction factor (VRF) was adopted to quantify the accuracy of the soil moisture validation sites, and the average VRF was estimated at 4.88%. The validation results were enhanced by excluding validation sites with VRF errors greater than 5% from the statistical analysis. Although the ESA CCI SM underestimated the in situ observations with a Bias of 0.05 m3/m3, a moderately high correlation coefficient of 0.44 and a relatively small unbiased root‐mean‐square difference of 0.05 m3/m3 were observed. This study provides information on the utilization of ESA CCI SM for ecological protection, climate change, and hydrological forecasting. It also suggests the adoption of VRF for future error corrections of satellite‐based products. |
| |
| Keywords: | soil moisture variance reduction factor European Space Agency Climate Change Initiative soil moisture product climate change remote sensing soils |
|
|
