安徽农业科学Issue(19)：10209-10215,10344,8.
一次河北强降雪天气过程物理量诊断分析
Physical Diagnosis of a Heavy Snowfall in Hebei
摘要
Abstract
A regional snow storm in Heibei on November 8-12, 2009 was analyzed with Micaps, physical field profile and synchronous data from island stations. The results showed that the storm was caused by factors in three different spatial and temporal scales, rain on November 8 was caused by the southward movement of weak shear in the strong frontal zone and fog lifted early on; snow storm on November 9-10 was due to the specific circulation context of synoptic-scale frontal zone, convergence zone of three air currents from different levels of temperature and humidity which just covered east of Hebei; snow during November 11-12 was caused by eastward movements of new trough generated when circulation was quickly adjusted. As indicated by the physical analysis, during heavy snowfall in Shijiazhuang region on November 9 -10, air below 850 hpa was downdraft, i. e. snow from increased air pressure, and high-u region of easterly from Bohai Sea to Taihang Mountains and specific humidity lasted from 8th to 10th. During November 11 - 12 new low-pressure air reached maximum central vertical velocity of -10.0 hpa/H, and 12 hours later moved backward by 45 °, with central value of -7. 0 hPa/ H. The specific humidity center reached height of 600 hPa during obvious systematic snow. The height fell to 700 hpa when it moved to east Hebei and snow started, and formed a dual-system with high specific humidity region of 850 hpa, and it moved east to the sea rapidly with the system. Al 20:00, the cold air from the loop region entered west of the Taihang Mountains and the snow gradually stopped. And the low-value system rapidly moved eastward to east of North China and caused snow. Before the snow in east of Nurth China, easterly of North China with velocity over 16 m/s lasted over 18 hours- Water vapor transport of direction of major wind in central Bohai Sea region below 950 hpa has indicative significance of the dynamics in snowfall zones. Hazardous weather derived of different regions was caused by continuous snow, low temperature and specific terrain.关键词
强降雪时空尺度/天气过程/物理量/诊断分析/河北Key words
Spatial and temporal scales of heavy snowfall/ Weather process/ Physical quantity/ Diagnostic analysis/ Hebei分类
农业科技引用本文复制引用
齐义君,李延江,葛红萍,周耘翁..一次河北强降雪天气过程物理量诊断分析[J].安徽农业科学,2012,(19):10209-10215,10344,8.基金项目
公益性行业项目(GYHY201106006). （GYHY201106006）
