【摘要】 利用1961-2010年地面气象观测数据、2008年1月10日至2月15日和2013年12月10-20日ERA-Interim 0.125°×0.125°再分析数据以及DEM地形高度数据,研究了昆明准静止锋(Kunming Quasi-Stationary Front,KQSF)位置、云贵高原地形和锋面附近大气要素三者之间的关系。研究结果表明:(1)云贵高原以乌蒙山脉(103°E)分为东、西两部,云贵高原东部地区昆明准静止锋出现的频次为61.5%,西部地区出现频次为38.5%,大部分冷空气被阻挡在了云贵高原东部地区,仅有少部分较强冷空气能越过乌蒙山脉进入云贵高原西部,高原大地形对冷空气的阻滞作用显著;(2)昆明准静止锋的进退与锋面前后地面温压场关系有较好的相关性,锋后冷气团越强、锋前暖气团越弱,锋面位置越偏西,反之越偏东,其相关的显著性主要体现在云贵高原西部,而在高原东部地区,地形作用降低了锋面位置与温压场的相关性;(3)高原地形阻挡作用使冷空气移动速度缓慢甚至停滞而形成准静止锋,抬升作用使局地近地层形成顺时针的次级环流,导致逆温层的出现,一旦冷空气越过高原,抬升作用减弱,逆温层消失;(4)东西风零线能较好地描述锋面位置和冷气团厚度,体现了KQSF呈准南北向和云贵高原地区的冷空气由东向西路径特征;(5)锋后冷高压的位势高度可表示冷气团的厚度,在云贵高原东部锋面位置取决于冷气团的厚度,当锋面到达云贵高原西部后,地形的阻挡作用显著减弱和消失,锋面位置取决于冷暖气团之间势力的强弱对比。更多还原

【Abstract】 Using ground meteorological observation data from 1961 to 2010,ERA-Interim reanalysis data from January 10 to February 15,2008 and December 10 to 20,2013 and terrain elevation data of digital elevation model( DEM),the relationships of Yunnan-Guizhou Plateau topography,position of Kunming quasi-stationary front( KQSF) and meteorological elements near the front were analyzed. The main results are as follows:( 1)The Yunnan-Guizhou Plateau is divided into the eastern and the western in Wumeng Mountains( 103° E). The KQSF present frequency is 61. 5% in the eastern area of Yunnan-Guizhou Plateau,the frequency of the western region is 38. 5%. Most of the activity of cold air is blocked in the eastern area of Yunnan-Guizhou Plateau. Only a small part of the strong cold air activity can across Wumeng Mountains,and get into the western area of Yunnan-Guizhou Plateau. The effect of plateau topography on cold air activity is significant.( 2) There is a good correlation between the advance( retreat) of KQSF and the temperature and pressure field before( after) the frontline. The stronger the cold air mass after KQSF,the weaker the warm air mass before KQSF,the KQSF position is more westerly. On the contrary,the KQSF position is more easterly. The significant correlation is mainly reflected in the western area of Yunnan-Guizhou Plateau. The effect of terrain reduced the correlation in the western area of Yunnan-Guizhou Plateau.( 3)Blocking effect of plateau topography makes cold air activities moving slowly,or even stagnation and leads to the formation of quasi stationary front. Uplift effect of plateau topography results in the formation of clockwise secondary circulation in local lowlayer,leading to the emergence of the inversion layer. Once the lifting effect is weakened when the cold air passes over the plateau,the inversion layer will disappear.( 4)The zero line of zonal wind can describe the front position and the cold air mass thickness,which illustrates that the distribution of KQFS is quasi-North-South. And characteristics of cold air path is from east to west.( 5) The potential height after front can indicate the thickness of the air mass. In the eastern part of the Yunnan-Guizhou Plateau,the frontline position depends on the thickness of the cold air mass. In the eastern part,the frontline position depends on contrasted dynamics between the cold and warm air mass.更多还原