| 一次冬季锋面暴风雪天气过程的斜压边界层特征的观测分析 |
| |
| 作者姓名： | Xu Yinlong Qian Fenlan Chen Zhi Li Shiming Zhou Mingyu |
| |
| 作者单位： | XuYinlong Agrometeorology Institute，Chinese Academy of Agricultural Sciences，Beijing 100081 Qian Fenian，Chen Zhi，Li Shiming and Zhou Mingyu National and Center for Marine Environmental Forecast Research，Beijing 100081 |
| |
| 基金项目： | This research was financially supported by the National Natural Science Foundation of China under Grant No. 49675251. |
| |
| 摘 要： | 对STORM-FESTIOP17一次冬季锋面暴风雪天气过程的斜压边界层结构演变及特征进行了分析。发现：暖湿空气沿锋面抬升凝结成云，产生降水过程中释放的大量潜热显著增加锋两侧的水平温度差异，产生锋生。与锋生相伴，在锋前产生低空急流和高空急流。当锋生至最强时，锋两侧温差可达20K，锋前低空急流开始减弱，锋后低空急流增强，锋后冷平流开始主导锋两侧的环流系统。该冷平流削弱锋两侧的温度水平梯度，产生锋消作用。对这次锋面斜压对流边界层的湍流特征分析表明：在边界层之上切应力wv明显增大；湍能收支分析表明在边界层之上的风切变产生项很强，即大尺度天气系统有利于斜压对流边界层的发展，边界层内各量充分混合。这次冬季锋面暴风雪天气过程，冷锋前的低空南风急流从墨西哥湾携带来的充足水汽及锋区边界层大气的强斜压性是其产生的关键因子：冷锋过后，大尺度高空急流的作用更有利于对流边界层的充分发展。
|
| 关 键 词： | 锋生 斜压边界层 冬季 暴风雪 天气过程分析 高空急流 |
| 收稿时间： | 8 January 2001 |
Observational analyses of baroclinic boundary layer characteristics during one frontal winter snowstorm |
| |
| Xu Yinlong,Qian Fenlan,Chen Zhi,Li Shiming,Zhou Mingyu.Observational analyses of baroclinic boundary layer characteristics during one frontal winter snowstorm[J].Advances in Atmospheric Sciences,2002,19(1):153-168. |
| |
| Authors: | Xu Yinlong Qian Fenian Chen Zhi Li Shiming Zhou Mingyu |
| |
| Institution: | Agrometeorology Institute, Chinese Academy of Agricultural Sciences, Beijing 100081,National and Cemter for Marine Environmental Forecast Research, Beijing 100081,National and Cemter for Marine Environmental Forecast Research, Beijing 100081,National and Cemter for Marine Environmental Forecast Research, Beijing 100081,National and Cemter for Marine Environmental Forecast Research, Beijing 100081 |
| |
| Abstract: | The evolution and characteristics of the baroclinic boundary layer for one frontal winter snowstorm were analyzed by using the well-documented dataset during Intensive Observation Period (IOP) 17 of STORM-FEST. It is found that when the warm moist air was lifted across the front, a great amount of la tent heat release because of snowing increased the frontal temperature contrast to intensify frontogenesis. Itis shown in the zig-zag section diagram of potential temperature that when the frontogenesis got stronger, a cold trough was formed and both low-level jet (LLJ) and upper-level jet (ULJ) emerged ahead of the front.In the strongest stage of frontogenesis, the frontal contrast of potential temperature of cold trough reached as high as 20 K. Hereafter the LLJ ahead of the front tended to weaken and the LLJ behind the front tended to strengthen. The frontal circulation system was dominated by the cold air advection behind the front,which transported the cold air behind the front forward to the warm area ahead of the front to weaken the cold trough and finally frontolysis occurred. It is shown by the analyses of turbulent characteristics of front al baroclinic boundary-layer that the vertical shear (wv) above the boundary layer was very large, and the pumping of the strong wind shear in turbulent energy budget made the characteristic variables within the PBL well mixed. Sufficient moisture carried by southerly flow from the Mexico Gulf, and the strong baroclinity of the frontal boundary layer played key roles in this frontal winter snowstorm, and the large-scale ULJ behind the cold front is also advantageous to the development of the convective boundary layer. |
| |
| Keywords: | STORM-FEST Frontogenesis Baroclinic boundary layer Winter snowstorm |
| 本文献已被 CNKI 维普 万方数据 SpringerLink 等数据库收录！ |
| 点击此处可从《大气科学进展》浏览原始摘要信息 |
| 点击此处可从《大气科学进展》下载免费的PDF全文 |
