1979-2012年平流层大气的基本特征分析  

Analysis of basic stratospheric characteristics for the period 1979-2012

作　　者：郭琪[1] 刘晨 张镭[1] 苑广辉[1] 李雪洮 Guo Qi;Liu Chen;Zhang Lei;Yuan Guang-hui;Li Xue-tao(Key Laboratory of Semi-Arid Climate Changes with the Ministry of Education,College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,China;Troops 94608,Chinese People＇s Liberation Army,Nanjing 211500,China)

机构地区：[1]兰州大学大气科学学院半干旱气候变化教育部重点实验室 [2]中国人民解放军94608部队

出　　处：《兰州大学学报（自然科学版）》2018年第3期323-333,共11页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(41475008;41521004)

摘　　要：利用1979-2012年ERA-Interim资料,分析了期间平流层温度、纬向风速和位势高度等基本气象要素场的季节分布和年际变化特征,探讨了行星波活动的空间分布及演变趋势,行星波和基本要素场之间的相关性.结果表明,1979-2012年平流层中高层的温度呈负趋势,导致平流层中的位势高度场逐年降低.热带地区平流层的纬向风速逐年递增,而南北半球高纬极地的平流层上层的纬向风速呈负的变化趋势,是极地平流层变冷趋势通过热成风原理作用的结果.冬季北极极涡在过去几十年有所减弱,但南极极涡风速却逐渐增强.对行星波活动的分析发现,平流层中的行星波在过去30 a中不断增强,对流层中的行星波呈现一定的减弱趋势.由于平流层行星波的增强,北极平流层极涡风速变弱,温度升高,表明北极极涡在不断减弱.The seasonal and lnterannual variations in stratospheric temperature, zonal wind and geopoten- tial height for the period 1979-2012 were analyzed using ERA-Interim reanalysis data. The spatial char- acteristics of planetary wave and its trends as well as the relationship between planetary waves and strato- spheric basic parameters were also investigated in this study. The results indicated that, due to the emis- sion of greenhouse gases and ozone loss, the temperature in the upper stratosphere showed a negative trend during the past 34 a, leading to the decrease of geopotential heights in the stratosphere. The nega- tive trend also appeared in the zonal wind in the middle and upper stratosphere in the tropics, high lati- tudes and polar regions in the Antarctic. The strengthening of the Antarctic polar vortex might be related to the ozone loss. By contrast, the Arctic zonal westerly showed a negative trend, suggesting that the Arc- tic polar vortex was weakening during the past decades. The analysis of interannual variations in plane- tary waves, and the amplitude of stratospheric planetary waves were increasing during the past 30 a due to an increase in the wave refractive index. On the contrary, the tropospheric wave was weakening. The strengthening of stratospheric planetary wave led to a weakening of stratospheric polar vortex in the Arc- tic accompanied by a warmer temperature and reduced wind in recent decades.

关 键 词：平流层 年际变化 极涡 行星波 

分 类 号：P421[天文地球—大气科学及气象学]