摘要
利用对流层至平流层大气变量的物理分解,本文发现400hPa上的天气尺度温度扰动正值和250hPa上的天气尺度高度扰动正值能够指示地面上的高温和热浪事件.理论和观测分析发现,当扰动静止波中心出现在40°N—45°N时,准静止波波长较长,影响范围大,持续时间久,容易在中国形成区域持续性热浪事件.在江南—华南、长江沿江及河套—华北的区域,干热浪事件静止波的稳定时间在6.5天以上.对流层大气天气尺度扰动波动在垂直方向具有倾斜特征,250hPa高度上,静止波稳定位置比地面热浪区域中心普遍偏北6～12个纬距.在低纬度(副热带高压带南侧),大气中向西北方向移动的天气尺度扰动,只有到达副高脊线以北的西风带后,才能形成静止波.
By using the principle of physical decomposition of atmospheric variables from troposphere to stratosphere, it was found that the 400 hPa regional-scale positive temperature anomaly and the 250 hPa regional-scale positive geo-potential height anomaly can well indicate the ground higher temperature and heat wave （HW） events. Theoretical analysis and case study present that near 43°N the regional-scale quasi-stationary wavelength reaches its maximum, where the wave is stable to produce regional-persistent HW events. The regional-scale quasi- stationary waves associated with dry HW events in South China, the south of Yangtze River, along the middle and lower reaches of the Yangtze River and North China remain above 6.5 days. The center of regional-scale quasi-stationary wave is 6-12 latitudes in the north of regional dry HW central positions on average. The northwestward-shift regional-scale wave in the low latitudes （on the south of the Subtropical High） becomes stationary only when it reaches the westerly region in the north of the Subtropical High ridge.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第5期1487-1500,共14页
Chinese Journal of Geophysics
基金
国家科技支撑计划(2009BAC51B04)
气象行业专项(GYHY201006018)资助
关键词
热浪事件
扰动结构
温度扰动
高度扰动
动力学分析
Heat wave event, Anomaly structure, Temperature anomaly, Height anomaly,Theoretical analysis
