Spatial-Temporal Characteristics of Regional Extreme Low Temperature Events in China during 1960-2009

摘要

An objective identification technique is used to detect regional extreme low temperature events(RELTE) in China during 1960-2009.Their spatial-temporal characteristics are analyzed.The results indicate that the lowest temperatures of RELTE,together with the frequency distribution of the geometric latitude center,exhibit a double-peak feature.The RELTE frequently happen near the geometric area of 30 N and 42 N before the mid-1980s,but shifted afterwards to 30 N.During 1960-2009,the frequency,intensity,and the maximum impacted area of RELTE show overall decreasing trends.Due to the contribution of RELTE,with long duration and large spatial range,which account for 10% of the total RELTE,there is a significant turning point in the late 1980s.A change to a much more steady state after the late 1990s is identified.In addition,the integrated indices of RELTE are classified and analyzed.