Mapping Snowmelt Progression in the Himalaya-Karakoram Region With Sentinel-1 SAR
Abstract
Known as the 'third pole,' snow and glaciers of the Himalaya-Karakoram (HK) region play an integral role in the surface energy budget as well as provide critical water resources for densely populated downstream river basins including the Indus, Ganges, and Brahmaputra. Cryospheric responses to climate change in the region are heterogeneous in both space and time; limited field measurements challenge current understanding of these complex systems and also yield substantial uncertainty in predicting their status in coming decades.
Utilizing remote sensing data with differing temporal, spatial, and spectral resolutions can offer greater insight into surface states for snow and ice, especially useful in regions with limited field measurements. The European Space Agency's Sentinel-1 (S1) synthetic aperture radar (SAR) sensor yields publicly available imagery with an overpass repeat in the HK region of approximately 12 days. Microwave wavelengths of SAR sensors provide different information than can be garnered from optical sensors, and have the benefit of collecting data regardless of cloud cover or time of day. SAR-derived wet snow maps have been developed and used operationally in other mountainous areas such as the Alps; knowledge of liquid water presence in the snowpack can provide useful information for both energy balance modeling and runoff forecasting. In this study, in conjunction with the NASA-ISRO SAR mission, we move towards developing regional HK wet snow products derived from S1 imagery for melt seasons 2016-2019. We validate findings with multiple data sources including MODIS-derived land surface temperatures and snow cover areas, snow cover maps developed from Sentinel-2 and Landsat8 sensors, High Mountain Asia ASCAT Freeze/Thaw/Melt Status, and local measurements where available.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C51B1273L
- Keywords:
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- 0720 Glaciers;
- CRYOSPHERE;
- 0740 Snowmelt;
- CRYOSPHERE;
- 0758 Remote sensing;
- CRYOSPHERE;
- 0776 Glaciology;
- CRYOSPHERE