On the role of horizontal resolution over the Tibetan Plateau in the REMO regional climate model
On the role of horizontal resolution over the Tibetan Plateau in the REMO regional climate model
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DOI：
10.1007/s00382-018-4085-7
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发表时间：
2018-02
期刊：
影响因子：
4.6
通讯作者：
Jingwei Xu;Nikolay Koldunov;A. Remedio;D. Sein;Xiefei Zhi;Xi Jiang;Min Xu;Xiuhua Zhu;K. Fraedrich;D. Jacob
中科院分区：
文献类型：
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作者：
Jingwei Xu;Nikolay Koldunov;A. Remedio;D. Sein;Xiefei Zhi;Xi Jiang;Min Xu;Xiuhua Zhu;K. Fraedrich;D. Jacob
一些研究表明，通过提高区域气候模式的水平分辨率，捕捉更多的精细尺度天气过程，可以获得附加值。然而，导致这种附加值的机制是不同的地形复杂的地区，如青藏高原（TP）。为了确定水平分辨率对TP的作用，对1980-2007年期间分辨率为25和50 km的REMO区域气候模式的结果进行了详细的比较。该模型是由欧洲中期天气预报中心中期再分析数据在横向边界驱动的。实验的不同之处仅在于地形的表示，所有其他土地参数（例如，植被特征、土壤质地）是相同的。结果表明，高分辨率地形影响了青藏高原边缘近地面区域的大气环流，导致大气水汽输送的再分配，尤其是雅鲁藏布江和伊洛瓦底江流域，使青藏高原南部的水汽输送增加了约5%。在对南太平洋高分辨率的模拟中，这反过来又使冬季2米处的温度显著降低了1.5 °C以上。因此，地形对TP上方2 m温度的影响是通过影响大气水汽在主要水汽路径中的输送来实现的。
A number of studies have shown that added value is obtained by increasing the horizontal resolution of a regional climate model to capture additional fine-scale weather processes. However, the mechanisms leading to this added value are different over areas with complicated orographic features, such as the Tibetan Plateau (TP). To determine the role that horizontal resolution plays over the TP, a detailed comparison was made between the results from the REMO regional climate model at resolutions of 25 and 50 km for the period 1980–2007. The model was driven at the lateral boundaries by the European Centre for Medium-Range Weather Forecasts Interim Reanalysis data. The experiments differ only in representation of topography, all other land parameters (e.g., vegetation characteristics, soil texture) are the same. The results show that the high-resolution topography affects the regional air circulation near the ground surface around the edge of the TP, which leads to a redistribution of the transport of atmospheric water vapor, especially over the Brahmaputra and Irrawaddy valleys—the main water vapor paths for the southern TP—increasing the amount of atmospheric water vapor transported onto the TP by about 5%. This, in turn, significantly decreases the temperature at 2 m by > 1.5 °C in winter in the high-resolution simulation of the southern TP. The impact of topography on the 2 m temperature over the TP is therefore by influencing the transport of atmospheric water vapor in the main water vapor paths.