Sujay V. Kumar

SWOT‐Fitted River Bathymetry for Global Hydrodynamic Models

We present a robust, global method to reconcile absolute water surface elevations (WSE) from the Surface Water and Ocean Topography (SWOT) mission with a large‐scale hydrodynamic model by iteratively correcting river bathymetry. After removing sensor and representativeness bias, we update riverbed elevations under DE...

Retrospective and Near–Real-Time Surface Meteorology in the North American Land Data Assimilation System Phase 3 (NLDAS-3)

High-resolution, reliable surface meteorological estimates are essential for hydrologic modeling, climate research, and disaster management. Previous phases of the North American Land Data Assimilation System (NLDAS-1 and NLDAS-2), developed jointly by NOAA, NASA, and academic partners, established widely used observ...

Beyond SMAP: Can GNSS‐R Platforms Ensure Continuity of Global Soil Moisture Observations?

The absence of a definitive follow‐on strategy for the Soil Moisture Active Passive (SMAP) mission, which has already surpassed its planned mission lifetime, presents a significant challenge for the hydrological science community. GNSS‐Reflectometry (GNSS‐R), which exploits reflected satellite navigation signals, has e...

A Community Perspective on Hydrologic Science Opportunities for Earth Observations

Existing satellite systems primarily observe individual components of the terrestrial water cycle, whereas drought is fundamentally an emergent, temporary process resulting from interactions among all terrestrial water storage compartments and human water use (AghaKouchak et al., 2015; AghaKouchak et al., 2021). Given...

Comparing 3 m resolution snow cover downscaled from MODIS, VIIRS, and HLS using commercial satellite imagery and terrain information