Interannual variations of the discharge of Amu Darya and Syr Darya estimated from global atmospheric precipitation

The discharges of two main rivers of the basin of the Aral Sea (Amu Darya and Syr Darya) was estimated from two global data sets of monthly atmospheric precipitation (GPCP, collected in 1979–2001 and GPCC, collected in 1986–2001) integrated over the areas of formation of the discharge of these two rivers. Both seasonal and interannual variations of atmospheric precipitation are evident. A decreasing trend is evident in Amu Darya discharge; the discharge of Syr Darya did not decrease since 1985. Both trends well correspond to interannual variability of the sea level of two independent basins of the Aral Sea (the Large Sea and the Small Sea) derived from the TOPEX/Poseidon satellite altimetry (1992–2002).