CoAuthors

Charon Birkett (University of Maryland, USA); Jean-François Crétaux (LEGOS, France); James Carton (University of Maryland, USA); Brian Beckley (SGT, Inc., USA); Xu Yang (SGT, Inc., USA)

Multi-mission satellite radar altimetry measurements of lake and reservoir surface water level complement in situ observations by providing stage information for un-gauged basins and by filling data gaps in poorly gauged basins, increasing the final climate data record. As different satellite radar altimeter-derived inland water level products may differ significantly owing to the choice of satellites and data processing methods, we explore the impacts of these differences. We present a direct comparison between three different altimeter-based inland water level estimates (USDA/NASA GRLM, LEGOS and ESA-DMU) and a validation with gauge time series for lakes and reservoirs of a variety of sizes and conditions. In addition, availability of satellite-based rainfall and lake/reservoir level offers exciting opportunities to estimate and monitor additional hydrologic properties of the lake systems. A simple water balance model is utilized to relate a net freshwater flux over a catchment basin to the lake/reservoir level for tropical lakes and reservoirs. This approach can be used to output water-level hindcasts and forecasts. Such a modeling tool, together with the long-term altimeter records, is fundamental for understanding past, present and future variations in lake/reservoir levels and enabling a better understanding of its climatic variations on inter-annual to inter-decadal time-scales.