| 摘要: |
| 利用EAR5再分析气象数据,分析了两次昆明准静止锋天气过程的高低空环流形势、锋面结构、锋面位置、以及相关要素场等基本特征及其异同。结果表明：中高纬度地区阻塞形势的存在是昆明准静止锋形成的背景环流。当冷暖气团均强且势均力敌时,更有利于锋面的维持；冷空气较强时,锋面会向西移动,越过云贵高原地形的阻挡；反之,锋面则会向东移动。当锋面维持在高原地形东侧时,冷空气被地形阻挡时,锋面的移动缓慢,此时锋区最为明显。当锋面维持在地形东侧时,风场的最大水平切变、温度的最大水平梯度和相当位温的密集区,描述的锋面位置几乎相同。两次过程寒潮爆发时冷空气均只能维持到700hPa附近,且水平风场也均为600hPa以下的低空切变,说明昆明准静止锋为浅薄系统。昆明准静止锋与一般冷锋锋后不同,两次个例昆明准静止锋锋后低空为湿区,而锋前水汽是否充足则要看南支槽所处的位置。 |
| 关键词: 昆明准静止锋;相当位温;云贵地区 |
| DOI： |
| 投稿时间：2021-08-15修订日期：2022-07-26 |
| 基金项目: |
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| Analysis of the frontal characteristics of Kunming quasi-stationary front |
| Li rui,Meng Qingyi,Zhang meng,Meng Shihong |
| (Guizhou Qinglong County Meteorological Bureau,Guizhou Qinglong County;Meteorological Bureau of Qianxinan Prefecture,Guizhou Province) |
| Abstract: |
| Using EAR5 to reanalyze the meteorological data, the basic characteristics and similarities and differences of the high and low altitude circulation situation, front structure, front position, and related element fields of the two Kunming quasi-stationary front weather processes are analyzed. The results show that the existence of the blocking situation in the middle and high latitudes is the background circulation formed by the Kunming quasi-stationary front. When the heating and cooling masses are strong and evenly matched, it is more conducive to the maintenance of the front. When the cold air is strong, the front will move westward, crossing the terrain of the Yunnan-Guizhou Plateau; otherwise, the front will move eastward. When the front is maintained on the east side of the plateau terrain and the cold air is blocked by the terrain, the movement of the front is slow, and the front area is most obvious at this time. When the front is maintained on the east side of the terrain, the maximum horizontal shear of the wind field, the maximum horizontal gradient of temperature and the dense area of equivalent potential temperature describe almost the same front position. During the two cold wave outbreaks, the cold air can only be maintained to around 700hPa, and the horizontal wind field is also low-altitude shear below 600hPa, indicating that the Kunming quasi-stationary front is a shallow system. The Kunming quasi-stationary front is different from the general cold front. In two cases, the low altitude behind the Kunming quasi-stationary front is a wet area, and whether the water vapor before the front is sufficient depends on the location of the south branch trough. |
| Key words: Kunming quasi-stationary front; Equivalent potential temperature; Yunnan-Guizhou region |
