trend and cycle analysis of annual and seasonal precipitation in liaoning, china

Annual and seasonal precipitation data for 49 meteorological stations over the period of 1960–2006 in Liaoning province were analyzed. Liaoning experienced province-wide decreases in precipitation over the 47-year period, with annual precipitation decreasing by 96% of the stations, followed by 92, 84, 63, and 27%, respectively, for summer, autumn, spring, and winter precipitation. Regional trend analysis confirmed the province-wide decrease, which was detected by the site-specific analysis, but a greater number of significant declines were found for annual, summer, and autumn precipitation for Liaoning province and for three of its four subregions. Four significant cycles with alternation patterns were detected mainly at the time scales of 3–5, 10-11, 20–23, and 31.2 years for each of the four subregions (Liaodong Peninsula, Northeastern Mountain, Western Highland, and Central Plain) and the entire Liaoning province, with the dominant periodicities being 10-11 years. The 10-11-year periodic variation of Liaoning annual precipitation was negatively associated with sunspot activity and positively associated with the East Asian Summer Monsoon (EASM) at the same time scale, while the 31.2-year periodic variation of Liaoning annual precipitation was positively correlated with both the EASM and ENSO activities at the 30–33-year time scale.