Ganga‐Brahmaputra river discharge from Jason‐2 radar altimetry: An update to the long‐term satellite‐derived estimates of continental freshwater forcing flux into the Bay of Bengal

This paper discusses the use of Jason‐2 radar altimeter measurements to estimate the Ganga‐Brahmaputra surface freshwater flux into the Bay of Bengal for the period mid‐2008 to December 2011. A previous estimate was generated for 1993–2008 using TOPEX‐Poseidon, ERS‐2 and ENVISAT, and is now extended using Jason‐2. To take full advantages of the new availability of in situ rating curves, the processing scheme is adapted and the adjustments of the methodology are discussed here. First, using a large sample of in situ river height measurements, we estimate the standard error of Jason‐2–derived water levels over the Ganga and the Brahmaputra to be respectively of 0.28 m and 0.19 m, or less than ∼4% of the annual peak‐to‐peak variations of these…