Interannual change in summertime precipitation over northeast Asia

[ 1] The summertime precipitation over northeast Asia ( Mongolia and Inner Mongolia) increased from 1980 to the mid-1990s, and low-precipitation summers continued for 4 years from 1999. A vegetation index based on satellite observations shows a similar interannual change. The first EOF mode of the interannual change of July precipitation shows a seesaw pattern between northeast Asia and Siberia, and the time coefficient represents the summertime precipitation change over northeast Asia. This mode is associated with Rossby waves propagating eastward over the Eurasian continent, which accompany anomalous meridional winds over northeast Asia and Siberia, resulting in anomalous vertical flows. The vertical flows over these regions are connected with each other through the meridional circulation, which contributes to form the seesaw pattern by suppressing or enhancing the precipitation.