Role of clouds in accelerating cold-season warming during 2000-2015 over the Tibetan Plateau
Role of clouds in accelerating cold-season warming during 2000-2015 over the Tibetan Plateau
复制标题
2000-2015年青藏高原冷季变暖过程中云的作用
DOI：
10.1002/joc.5709
复制
发表时间：
2018-11-15
期刊：
影响因子：
--
通讯作者：
Wang, Bing
中科院分区：
文献类型：
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作者：
Hua, Shan;Liu, Yuzhi;Wang, Bing
与1961 - 1999年的+0.04℃/ 10年的增温速率相比，2000-2015年的增温速率为+0.30℃/ 10年。同期，青藏高原冷季（11月~ 3月）的增温明显高于暖季（5月~ 9月）。冷季几乎所有TP的中层云（middle cloud）减少（-0.359%/年），高层云（high cloud）增加（+0.241%/年）。进一步分析表明，2000-2015年青藏高原西部的净云辐射强迫为正，即云层的加热效应，尤其是在寒冷季节。结合青藏高原大部分地区高云量增加、中云量减少的趋势，认为中云反照率的减弱和高云长波温室效应的增强可能是造成2000 - 2015年寒季持续增温的部分原因。同时，随着海拔的升高，升温速率和云量变化显著增大。基于耦合模式比对项目第5期模式的分析表明，中云的减少比高空云的增加对青藏高原增温的调节作用更大，特别是在寒冷季节。
With the global warming slowdown in the twenty-first century, a huge discrepancy in regional climate warming has been identified over the main region of the Tibetan Plateau (TP). Compared with the +0.04 degrees C/decade warming from 1961 to 1999, the warming greatly accelerated for the period 2000-2015 at a rate of +0.30 degrees C/decade. During the same period, warming in the cold season (November to March) was more pronounced than in the warm season (May to September) over the TP. The results also indicated that the middle-level cloud (middle cloud) decreased (-0.359%/year), while the high-level cloud (high cloud) increased (+0.241%/year) over almost all the TP during the cold season. Further analysis showed positive net cloud radiative forcing over the western TP from 2000-2015, that is, a heating effect of clouds, especially in the cold season. Combining the trends of the increase in high cloud and the decrease in middle cloud over most parts of the TP, the decreased albedo effect of middle cloud and the increased longwave greenhouse effect of high cloud may have partially contributed to the sustained warming, especially in the cold season from 2000 to 2015. Meanwhile, the results showed that the warming rate and cloud area fraction changes were significantly amplified with elevation. The analysis based on a model of Coupled Model Intercomparison Project Phase 5 shows that the decreased middle cloud plays more important role than the increased high cloud in modulating the enhanced warming over the TP, especially in the cold season.