【摘要】 使用欧洲中期天气预报中心(European Center for Medium-Range Weather Forecasts,ECMWF)臭氧与风场资料,采用后向轨迹模型对青藏高原区域对流层3个层次(450 hPa,250 hPa,150 hPa)进行模拟分析。结果显示:(1)青藏高原常年存在臭氧低值区,第一类出现在5～11月,臭氧低值中心显著;第二类出现在12月至次年4月,为浅薄的臭氧低谷,臭氧低值区范围与青藏高原海拔超过3 km地形相对应。(2)水平方向上青藏高原低层450 hPa气流源地主要为高原西侧同纬度地区,250 hPa主要来源为高原西侧及南侧地区,150 hPa主要来源为高原南侧;垂直方向上,青藏高原气流存在显著抬升。(3)受低纬度低层气流对臭氧浓度输送及高山地形的推挤和强迫抬升影响,青藏高原较同纬度其他地区臭氧浓度低,臭氧柱缩短,青藏高原臭氧出现静力亏损,为青藏高原臭氧低值区形成的重要原因。更多还原

【Abstract】 Based on the ozone mass mixing ratio and wind field data of the European Center for Medium-Range Weather Forecasts(ECMWF)data during 1984—2013,by using the tropospheric backward trajectory method,this paper has studied the characteristics and causes of the ozone low value center over the Tibetan Plateau.The analysis results of trajectories at different levels indicate that:(1)The ozone low value center over the Tibetan Plateau exists during a course of year,and can be divided into two types:one is significant low center appearing during May to November,and another is shallow trough of low ozone during December to April of the next year.The range of the ozone low value center almost coincides with that of the plateau terrain whose altitudes are over 3 km above sea level.(2)In the horizontal direction,the source areas of air current transporting to the Tibetan plateau are located in its west at 450 hPa,its west and south at 250 hPa,and its south at 150 hPa.In the vertical direction,the main feature of the air current over the Tibetan Plateau is the ascending motion.(3)The ozone concentration over the Tibetan Plateau is lower than that in other areas at the same latitude,because of the advection of the low layers air current coming from the low latitude and the orographic uplift and jostle effect.The main cause of the ozone low value center over the Tibetan Plateau is static depletion.更多还原