Variations in the Summer Monsoon Rainbands Across

Based on reconstructions of precipitation events from the rain and snowfall archives of the Qing Dynasty (1736--1911), the drought/flood index data mainly derived from Chinese local gazettes from 1736--2000, and the observational data gathered since 1951, the spatial patterns of monsoon rainbands are analyzed at different time scales. Findings indicate that monsoon rainfall in northern China and the middle-lower reaches of the Yangtze River have significant inter-annual (e.g., 5--7-yr and 2--4-yr) as well as inter-decadal (e.g., 20--30-yr and quasi-10-yr) fluctuation signals. The spatial patterns in these areas also show significant cycles, such as on a 60--80-yr time scale, a reversal phase predominates the entire period from 1736--2000; on a quasi-30-yr time scale, a consistent phase was prevalent from 1736 to 2000; and on a 20-yr time scale, the summer monsoon rains show different spatial patterns before and after 1870.