Abstract
Daily snow-covered area retrieval using the imagery in solar reflective bands often encounters extensive data gaps caused by cloud obscuration. With the inception of geostationary satellites carrying advanced multispectral imagers of high temporal resolution, such as Japan’s geostationary weather satellite Himawari–8, considerable progress can now be made towards spatially-complete estimation of daily snow-covered area. We developed a dynamic snow index (normalized difference snow index for vegetation-free background and normalized difference forest–snow index for vegetation background) fractional snow cover estimation method using Himawari–8 Advanced Himawari Imager (AHI) observations of the Tibetan Plateau. This method estimates fractional snow cover with the pixel-by-pixel linear relationship of snow index observations acquired under snow-free and snow-covered conditions. To achieve reliable snow-covered area mapping with minimal cloud contamination, the daily fractional snow cover can be represented as the composite of the high temporal resolution fractional snow cover estimates during daytime. The comparison against reference fractional snow cover data from Landsat–8 Operational Land Imager (OLI) showed that the root–mean–square error (RMSE) of the Himawari–8 AHI fractional snow cover ranged from 0.07 to 0.16, and that the coefficient of determination (R2) reached 0.81–0.96. Results from the 2015/2016 and 2016/2017 winters indicated that the daily composite of Himawari–8 observations obtained a 14% cloud percentage over the Tibetan Plateau, which was less than the cloud percentage (27%) from the combination of Moderate Resolution Imaging Spectroradiometer (MODIS) onboard Terra and Aqua.
Highlights
Snow cover, a spatially extensive and variable component of the Earth’s cryosphere, significantly affects the hydrologic cycle, weather, and climate
The instantaneous snow-covered area results between the Landsat–8 Operational Land Imager (OLI) and the Himawari–8 Advanced Himawari Imager (AHI) over the Tibetan Plateau were compared
To explore the potential of snow cover monitoring over the Tibetan Plateau with this geostationary weather satellite, we developed a feasible methodology to estimate the snow-covered area from the Himawari–8 AHI multispectral imagery
Summary
A spatially extensive and variable component of the Earth’s cryosphere, significantly affects the hydrologic cycle, weather, and climate. Water melted from seasonal snow cover provides essential water resources in middle- and high-latitude alpine areas [1,2]. In the Tibetan Plateau, snowmelt presents considerable contributions to the upstream areas of major Asian rivers [3,4,5]. The accumulation and depletion of snow cover has a significant influence on the surface energy balance and the climate system [7,8]. Previous studies revealed that East Asian atmospheric circulation and the summer monsoon are largely influenced by the snow cover dynamics of the Tibetan Plateau [9,10,11,12,13]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
