An exceptionally heavy snowfall in Northeast china: large-scale circulation anomalies and hindcast of the NCAR WRF model
An exceptionally heavy snowfall in Northeast china: large-scale circulation anomalies and hindcast of the NCAR WRF model
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DOI：
10.1007/s00703-011-0147-7
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发表时间：
2011-06
影响因子：
2
通讯作者：
Huijun Wang;Entao Yu;Song Yang
中科院分区：
文献类型：
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作者：
Huijun Wang;Entao Yu;Song Yang
在中国东北地区，降雪通常发生在冬季和早春，从十月中旬到三月下旬，仲春很少出现强降雪。 2010 年 4 月 12 日至 13 日期间，东北地区发生了一场异常强的降雪，东北地区最东部省份的省会哈尔滨市的积雪量达到了 26.8 毫米。在这项研究中，使用观测和模型分析了降雪的主要特征和相关的大规模环流以及降雪的可预测性。降雪前 10 天，西伯利亚高压增强并向东南移动，导致 4 月 12 日至 13 日期间 NEC 上空低压系统增强，东亚海槽增强。因此，NEC东部上空出现大面积水汽汇聚和强烈上升运动，导致降雪。后报实验是在 NCEP 全球预报系统数据集的强制下，使用 NCAR 天气研究和预报 (WRF) 模型以双向嵌套方法进行的。许多观测到的特征，包括大范围和区域性的环流异常和降雪量，都可以很好地再现，这表明WRF模型在预报NEC极端天气事件方面是可行的。定量分析还表明，嵌套的NEC域模拟在模拟降雪量和空间分布方面甚至优于母域模拟，并且两种模拟都比NCEP全球预报系统的输出更加熟练。嵌套预测系统的预测结果对于操作目的来说非常有希望。
In Northeast China (NEC), snowfalls usually occur during winter and early spring, from mid-October to late March, and strong snowfalls rarely occur in middle spring. During 12–13 April 2010, an exceptionally strong snowfall occurred in NEC, with 26.8 mm of accumulated water-equivalent snow over Harbin, the capital of the most eastern province in NEC. In this study, the major features of the snowfall and associated large-scale circulation and the predictability of the snowfall are analyzed using both observations and models. The Siberia High intensified and shifted southeastward from 10 days before the snowfall, resulting in intensifying the low-pressure system over NEC and strengthening the East Asian Trough during 12–13 April. Therefore, large convergence of water vapor and strong rising motion appeared over eastern NEC, resulting in heavy snowfall. Hindcast experiments were carried out using the NCAR Weather Research and Forecasting (WRF) model in a two-way nesting approach, forced by NCEP Global Forecast System data sets. Many observed features including the large-scale and regional circulation anomalies and snowfall amount can be reproduced reasonably well, suggesting the feasibility of the WRF model in forecasting extreme weather events over NEC. A quantitative analysis also shows that the nested NEC domain simulation is even better than mother domain simulation in simulating the snowfall amount and spatial distribution, and that both simulations are more skillful than the NCEP Global Forecast System output. The forecast result from the nested forecast system is very promising for an operational purpose.