Sensitivity Evaluation of Spectral Nudging Schemes in Historical Dynamical Downscaling for South Asia
Sensitivity Evaluation of Spectral Nudging Schemes in Historical Dynamical Downscaling for South Asia
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DOI：
10.1155/2017/7560818
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发表时间：
2017-04
影响因子：
2.9
通讯作者：
M. Ramzan;S. Ham;M. Amjad;E. Chang;K. Yoshimura
中科院分区：
文献类型：
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作者：
M. Ramzan;S. Ham;M. Amjad;E. Chang;K. Yoshimura
敏感性实验测试两个尺度选择性偏差校正（SSBC）的方法已经进行了识别的最佳光谱nudging计划的历史动态降尺度模拟南亚，使用协调的区域气候降尺度实验（CORDEX）协议和区域谱模式（RSM）。在短期极端夏季和长期年代际分析类别下选择了两个时间段。新的SSBC版本将轻推应用于全部风分量，在较低的模型层中增加了松弛时间，并结合了垂直加权阻尼系数。对2005年夏季南亚异常天气条件的评估证实了新SSBC在模拟季风降水时的优势。此外，新的SSBC方案被发现预测降水和风场模式更准确地比旧版本的年代际分析，这只适用于轻推旋转风场，在所有高度的恒定强度。
Sensitivity experiments testing two scale-selective bias correction (SSBC) methods have been carried out to identify an optimal spectral nudging scheme for historical dynamically downscaled simulations of South Asia, using the coordinated regional climate downscaling experiment (CORDEX) protocol and the regional spectral model (RSM). Two time periods were selected under the category of short-term extreme summer and long-term decadal analysis. The new SSBC version applied nudging to full wind components, with an increased relaxation time in the lower model layers, incorporating a vertical weighted damping coefficient. An evaluation of the extraordinary weather conditions experienced in South Asia in the summer of 2005 confirmed the advantages of the new SSBC when modeling monsoon precipitation. Furthermore, the new SSBC scheme was found to predict precipitation and wind patterns more accurately than the older version in decadal analysis, which applies nudging only to the rotational wind field, with a constant strength at all heights.