2005年山东半岛连续三次冷流暴雪过程的分析

The analyses of three snowstorm processes on Shandong peninsula in 2005

对2005年12月发生在山东半岛北部威海地区的三次冷流暴雪过程进行了分析研究,用WRF模式进行了数值模拟。分析结果表明:三次冷流暴雪发生时低空850hPa层强冷平流与地面降水强度有较好的对应关系;低层和地面都是偏西北风流场,半岛地区呈气旋性弯曲;地面风场存在风向辐合,特殊的地形和海陆温差在北部沿海地区形成海岸锋,为冷流的发生提供了有利的触发机制;从垂直面的风场辐合辐散高度说明了冷流过程较其他降水过程有着明显的低空性。

Three cold airstream snowstorm processes happened in Dec. in 2005 have been analysed and simulated by WRF model. The results declare that ： the cold airstream of 850hPa layer has good relationship with ground precipitation intensity in three cases; there are mainly NW wind fields on ground and at low level, which makes cyclonic curve on peninsula; wind convergence on ground and seashore front caused by special land and sea-land temperature difference provide burst mechanism for cold airstream course ; the height of wind divergence on vertical plane emphasizes the low level characteristic of cold airstream precipatition.