The impact of land cover generated by a dynamic vegetation model on climate over east Asia in present and possible future climate
The impact of land cover generated by a dynamic vegetation model on climate over east Asia in present and possible future climate
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DOI：
10.5194/esd-6-147-2015
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发表时间：
2014-10
期刊：
影响因子：
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通讯作者：
Mee-Hyun Cho;K. Boo;G. Martin;J. Lee;G. Lim
中科院分区：
文献类型：
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作者：
Mee-Hyun Cho;K. Boo;G. Martin;J. Lee;G. Lim
抽象的。本文研究了动态植被模型模拟的土地覆盖变化对亚洲夏季气候学的影响。这项研究中使用的气候模式存在系统偏差，低估了朝鲜周围的降雨量，高估了南中国海的降雨量。当与动态植被模型相结合时，由此产生的土地覆盖的变化伴随着产生粉尘的地区的额外的直接辐射效应。地表条件的直接变化和裸土比例增加对沙尘负荷的影响都影响着该地区的气候，在本研究中分别进行了研究。沙尘的直接辐射作用增加了降水偏差，而陆面物理过程则与中国北部的暖偏差等局地温度偏差有关。在未来气候的时间切片上，随着沙尘负荷的变化，模拟出了中国南海面异常的反气旋环流，导致中国海面降水减少，朝鲜半岛和中国南部降水偏多。与降雨量变化相比，土地覆盖变化和与之相关的沙尘辐射效应对未来以大气CO2增加为主的温度预测的影响很小。这项研究的结果表明，动态植被模式模拟的土地覆盖可以影响亚洲等沙尘排放源区的区域尺度上的模式系统偏差，并受其影响。特别是，分析与土地覆盖变化相关的沙尘变化的辐射影响，对于了解未来全球变暖下区域降水的变化非常重要。
Abstract. This study investigates the impacts of land cover change, as simulated by a dynamic vegetation model, on the summertime climatology over Asia. The climate model used in this study has systematic biases of underestimated rainfall around Korea and overestimation over the South China Sea. When coupled to a dynamic vegetation model, the resulting change in land cover is accompanied by an additional direct radiative effect over dust-producing regions. Both the change in land surface conditions directly and the effect of increased bare-soil fraction on dust loading affect the climate in the region and are examined separately in this study. The direct radiative effect of the additional dust contributes to increasing the rainfall biases, while the land surface physical processes are related to local temperature biases such as warm biases over North China. In time slice runs for future climate, as the dust loading changes, anomalous anticyclonic flows are simulated over South China Sea, resulting in reduced rainfall over the South China Sea and more rainfall near Korea and south China. In contrast with the rainfall changes, the influence of land cover change and the associated dust radiative effects are very small for a future projection of temperature, which is dominated by atmospheric CO2 increase. The results in this study suggest that the land cover simulated by a dynamic vegetation model can affect, and be affected by, model systematic biases on regional scales over dust emission source regions such as Asia. In particular, the analysis of the radiative effects of dust changes associated with land cover change is important in order to understand future changes in regional precipitation in global warming.