Long‐term trends in sunshine duration over Yunnan‐Guizhou Plateau in Southwest China for 1961–2005
Long‐term trends in sunshine duration over Yunnan‐Guizhou Plateau in Southwest China for 1961–2005
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DOI：
10.1029/2008gl034482
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发表时间：
2008-08
影响因子：
5.2
通讯作者：
Xiaobo Zheng;Wei-min Kang;T. Zhao;Y. Luo;C. Duan;Juan Chen
中科院分区：
文献类型：
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作者：
Xiaobo Zheng;Wei-min Kang;T. Zhao;Y. Luo;C. Duan;Juan Chen
云贵高原是我国西南部的低纬高原地区，包括云南和贵州两省。自世纪中期以来，云贵高原年平均气温呈降温趋势，是全球气候变暖背景下的一个显著区域气候现象。利用1961 - 2005年的日照时数和云量资料，对区域气候进行了研究。结果发现，在这45年的时间里，年日照时数减少主要是在24°N以北的YGP上，负趋势达到-11.8%，10年，而在同一时期，它增加，正趋势达到+3.5%，10年，在站集中在YGP西南部。20世纪70 ~ 80年代，三峡库区北方地区年日照时数总体呈加速下降趋势，80年代达到最大值，90年代以来下降速度明显减慢，进入21世纪世纪，年日照时数下降趋势已停止甚至逆转。45年来，长江三峡年平均云量的变化不明显，甚至呈下降趋势，对年日照时数的减少趋势影响不大。YGP上日照时数趋势和地面温度变化的一致模式支持了大气气溶胶负荷可能参与地面冷却趋势的假设。
Yunnan‐Guizhou Plateau (YGP), a low latitude highland region, covers the two provinces of Yunnan and Guizhou in Southwest China, where a cooling trend in the annual mean surface air temperature since the mid‐20th century was reported as a notable phenomenon of regional climate against the global warming. In this study on the regional climate, we applied the data of sunshine duration and cloud amount from 184 stations across the YGP from year 1961 to 2005. It was found that, over this 45 year period, annual sunshine duration decreased mostly north of 24°N on the YGP with the negative trends reaching −11.8% per decade, while during the same period it increased with the positive trends reaching +3.5% per decade at the stations concentrated on the southwestern YGP. An overall decline in annual sunshine duration over the northern YGP dramatically accelerated from the 1970s to 80s with its maximum rate in the 1980s, but has remarkably decelerated since the 1990s so that going into the 21st century the annual sunshine duration has ceased or even reversed its downward tendency. The evolution of annual mean cloud amount on the YGP was shown to be insignificant and even in decline over the 45 years, exerting less of an influence on the decreasing trends in the annual sunshine duration. The consistent patterns of sunshine duration trends and surface temperature changes on the YGP support the hypothesis that aerosol loading in the atmosphere could be involved in the surface cooling trend.