论文部分内容阅读
基于一个快速海气耦合模式(FOAM)在轨道强迫下对过去6000年全球气候的瞬变模拟结果,探讨了中全新世以来东亚夏季降水的时空演变特征。研究发现,中全新世以来东亚夏季降水对日射响应具有显著的时空不一致性。相对于现代,中全新世时东亚地区夏季约以30°N为界,以北地区降水偏少,以南地区降水偏多。自中全新世至今,北方地区夏季降水线性增多,而南方地区夏季降水线性减少,呈南北反相变化。相对于区域平均,局地夏季降水变化趋势则呈多样性,各地极值降水出现在中全新世以来的不同时间。自中国南部地区向北,以及蒙古国南部地区向西南方向,分别推进至华北和东北地区,最高值降水时问由6kaB.P.渐变到0kaB.P.,该特征与一些地质资料反映的全新世适宜期“不等时性”具有相似性。中全新世以来东亚夏季降水的时空不一致性可能源自轨道强迫下的一个南亚夏季风-东北亚夏季风(ISM-NEASM)遥相关,它导致了中国东部地区30°N南北两侧气压异常的反相变化,从而引起东亚夏季降水量值与演变的差异。
Based on the transient simulations of the global climate in the past 6,000 years under the orbital forcing of a fast sea-atmosphere coupling model (FOAM), the spatio-temporal evolution of the summer precipitation in East Asia since the Middle Holocene was discussed. The results show that the summer precipitation in East Asia has a significant spatiotemporal inconsistency with the response to the solar radiation since the Middle Holocene. Compared with the modern and middle Holocene, the East Asian region is about 30 ° N in summer, while the rainfall in the north is less than that in the south and the precipitation in the south is more. Since the Holocene, the summer rainfall in the northern region increased linearly, while the summer rainfall in the southern region decreased linearly with an opposite trend in the north and south. Compared with the regional average, the change tendency of the local summer precipitation is diversified, and the extreme precipitation in all places appears at different times since the middle Holocene. From south China to the north, and south of Mongolia to the southwest, respectively, to the north and northeast regions, the highest value of precipitation when asked by 6kaB.P. Gradual change to 0kaB.P., This feature and some of the geological data reflect the new World fit period “unequal time ” has similarities. The temporal-spatial heterogeneity of summer precipitation in East Asia since the middle Holocene may be due to the teleconnection of a South Asian summer monsoon-northeastern Asia summer monsoon (ISM-NEASM) under orbital forcing, which resulted in barotropic anomalies on the north and south sides of 30 ° N in eastern China Inverse phase change, which caused the difference between the value and evolution of summer precipitation in East Asia.