平流层大气重力波时空分布特征及其可能影响机制

大气重力波是一种普遍存在于大气层中的波动现象,与多种不同尺度天气现象均有密切联系,研究平流层重力波的时空分布特征及其可能影响机制对于全球大气环流、大尺度气候变化和各类中尺度天气系统的研究具有重要意义.利用基于PANGAEA数据中心提供的2002—2015年逐月平流层重力波参数资料和SPARC数据中心提供的1992—1997年逐月纬向风资料,分析了平流层重力波参数的时空分布特征,并讨论了影响平流层重力波变化的可能机制.结果表明,对于重力波参数的纬向平均分布,平流层重力波扰动温度和垂直波长随高度增加而增大,而水平波数和绝对动量通量则相反.在夏半球的中低纬度和冬半球的高纬度存在重力波参数的大值区,在赤道附近全年存在重力波参数的低值区.平流层重力波参数水平分布表现为纬向上的带状分布,强度随季节发生变化.在相同纬度,重力波参数的大值中心出现在大陆,特别是山脉地区.平流层纬向风和重力波参数二者的分布具有一致性,说明背景风对大气的扰动是影响重力波参数的可能机制之一.

Spatial and temporal distribution of atmospheric gravity waves in stratosphere and its possible influence mechanism

Atmospheric gravity wave is a common fluctuating phenomenon in the atmosphere. Stratosphere atmospheric gravity waves are closely related to many different scale weather phenomena. Study on the spatio temporal distribution characteristics of stratospheric gravity waves and their possible influence mechanisms are of great significance for the study of global atmospheric circulation, large scale climate change, and various kinds of mesoscale weather systems. The spatial temporal distribution characteristics of the stratospheric gravity wave parameters were analyzed based on the monthly data of stratospheric gravity wave parameters during 2002-2015 and the monthly zonal wind data during 1992-1997, and the influence mechanisms of which were also discussed. It showed that the stratospheric gravitational wave perturbation temperature and vertical wavelength increased with height, while the horizontal and absolute momentum fluxes were opposite. Higher gravitational wave parameters were distributed in the medium to low latitude of summer hemisphere and high latitude of winter hemisphere, while lower values concentrated near the equator throughout the year. The stratospheric gravitational wave parameters presented a ribbon distribution along the latitude and the intensity varied with season. At the same latitude, the center of higher gravity wave parameters appeared on land, especially the mountain areas. The consistent distribution between zonal wind and gravitational wave parameter indicated that the background wind disturbing the atmosphere was a possible influence mechanism of the gravitational wave parameters.