Changes in the Covariability of Surface Air Temperature and Precipitation over East Asia Associated with Climate Shift in the Late 1970s
Changes in the Covariability of Surface Air Temperature and Precipitation over East Asia Associated with Climate Shift in the Late 1970s
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DOI：
10.3878/j.issn.1674-2834.13.0063
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发表时间：
2013-08
影响因子：
2.3
通讯作者：
Ling-Yun Wu
中科院分区：
文献类型：
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作者：
Ling-Yun Wu
摘要 由于热力学关系，地表气温和降水的变化密切相关。 20 世纪 70 年代末的气候变化以及与之相关的东亚降水变化已有大量报道。然而，地表气温和降水的协变性如何响应气候变化尚不清楚。我们使用 1953 年至 2000 年期间观测到的平均 (Tmean)、每日最高 (Tmax) 和最低 (rmin) 地表气温和降水来探讨这个问题。结果表明，气候变化后，东亚部分地区Tmeaa与降水量的协变性发生了显着变化，且具有明显的季节依赖性。在气候变化之后的冬季，显着的负相关性占据了蒙古和中国的更多地区。相比之下，在气候转变后的夏季，除了一些小偏远地区相关性增强外，转变前几乎整个东亚地区存在的显着负相关性大多减弱。 Tmax 和降水量的协变性的变化显示出与 rmean 类似的空间模式，而 Tmin-降水量的协变性则不然。冬季，气候变化后，中国南方地区Tmin与降水量正相关性大幅减弱，而蒙古国地区显着负相关性区域有所增加。夏季，东亚地区Tmin-降水协变性变化呈现出从南到北负-正-负的格局，其中江淮流域和朝鲜地区出现正变化，华南、日本和东亚北部地区出现负变化。
Abstract Variations in surface air temperature and precipitation are closely associated because of their thermo-dynamic relations. The climate shift in the late 1970s and associated changes in precipitation over East Asia have been well reported. However, how the covariability of surface air temperature and precipitation responds to the climate shift is not yet well understood. We used the ob-served mean (Tmean), daily maximum (Tmax), and minimum (rmin) surface air temperatures and precipitation during the period of 1953–2000 to explore this issue. Results show that the covariability between Tmeaa and precipitation experienced remarkable changes over certain areas of East Asia after the climate shift with evident seasonal dependencies. In winter, after the climate shift significantly negative correlations occupied more areas over Mongolia and China. By contrast, in summer after the climate shift significantly negative correlations which existed over almost entire East Asia during the pre-shift period were mostly weakened with the exception of enhanced correlations over some small isolated areas. Changes in the covariability of Tmax and precipitation showed a similar spatial pattern to that of the rmean, whereas the Tmin-precipitation covariability did not. In winter, after the climate shift positive correlations between Tmin and precipitation over southern China were largely weakened, while the areas with significantly negative correlations increased over Mongolia. In summer, changes in Tmin-precipitation covariability appeared to be a negative-positive-negative pattern from south to north over East Asia, with positive changes occurring in the Yangtze-Huai River valley and Korea and negative changes occurring over South China and Japan, and northern part of East Asia.