平流层爆发性增温期间大气变化特性的COSMIC掩星观测

利用高精度和高垂直分辨率的COSMIC掩星观测资料,详细深入分析了2007年冬—2008年春平流层爆发性增温(SSW)期间10～60 km高度范围内大气的变化特性,尤其是上平流层和低中间层大气的变化特性.结果表明,在SSW过程中,温度场、风场和剩余环流都发生了明显的变化.根据温度在主增温前和主增温盛期的变化特性,在水平方向,大约以55°N为界,在垂直方向,大约以42 km为界,可以将温度场在纬度-高度的分布分为4个区域:高纬下层增温区,增温幅度约高达25 K;高纬上层降温区,降温幅度约达30 K;中纬下层降温区,降温幅度约为几K;中纬上层增温区,增温也约为几K.SSW期间上下层大气纬向风场的变化规律基本相同.在纬度方向以45°N为界,45°N以北地区的西风减弱东风增强,风场变化高达50 m/s;45°N以南地区西风增强东风减弱,变化幅度比较小,约10m/s.在2008年1月下旬到2月底,大气温度和纬向风有明显的振荡现象,周期约为12天.剩余环流的环流圈在SSW期间会发生反转,由此也表明,SSW期间大气中物质的输运方向也会发生改变.

Variability of the Atmosphere During the Sudden Stratospheric Warming Observed by the COSMIC Occultations

Observations of COSMIC occulations which have high precision and high height-resolustion from winter 2007 to spring 2008 are used to analyze the variability of the atmosphere between 10 and 60 km during the Sudden Stratospheric Warming(SSW),espetially the features in the upper stratosphere and lower mesosphere.Results show that all of the temperature and wind fields and the residual circulation changed significantly during the SSW.According to the differences of the temperature before and during the major S...