Equatorial wave analysis from SABER and ECMWF temperatures
Equatorial wave analysis from SABER and ECMWF temperatures
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DOI：
10.5194/acp-8-845-2008
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发表时间：
2007-08
影响因子：
6.3
通讯作者：
M. Ern;P. Preusse;M. Krebsbach;M. Mlynczak;James M. Russell
中科院分区：
文献类型：
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作者：
M. Ern;P. Preusse;M. Krebsbach;M. Mlynczak;James M. Russell
赤道行星尺度波模，如开尔文波或Rossby重力波，是由对流层中的对流过程激发的。在本文中，这些和其他赤道波模式进行了分析，特别侧重于平流层使用温度数据从SABER卫星仪器以及ECMWF温度。推导了对称谱功率和反对称谱功率的时空谱，以区分不同的赤道波类型，并根据时空谱的谱背景确定重力波的贡献。重力波和赤道行星尺度波模是平流层准两年振荡的主要驱动力。温度变化归因于不同的波类型计算从2002年2月至2006年3月期间，并与以前的研究结果进行比较。SABER和ECMWF波分析之间的比较表明，在平流层下部，SABER和ECMWF的谱和温度方差非常一致，而在平流层上部，ECMWF往往高估开尔文波分量。ECMWF部分地再现了重力波的方差，但有一个显着的低偏差。对于QBO西风阶段（2004年12月）和QBO东风阶段（2005年11月/12月，在达尔文/澳大利亚的SCUT-O3热带飞机运动期间）在平流层下部的例子，我们发现质量良好的协议之间SABER和ECMWF的开尔文，Rossby（n =1），和Rossby重力波的时间分布。
Equatorial planetary scale wave modes such as Kelvin waves or Rossby-gravity waves are excited by convective processes in the troposphere. In this paper an analysis for these and other equatorial wave modes is carried out with special focus on the stratosphere using temperature data from the SABER satellite instrument as well as ECMWF temperatures. Space-time spectra of symmetric and antisymmetric spectral power are derived to separate the different equatorial wave types and the contribution of gravity waves is determined from the spectral background of the space-time spectra. Both gravity waves and equatorial planetary scale wave modes are main drivers of the quasi-biennial oscillation (QBO) in the stratosphere. Temperature variances attributed to the different wave types are calculated for the period from February 2002 until March 2006 and compared to previous findings. A comparison between SABER and ECMWF wave analyses shows that in the lower stratosphere SABER and ECMWF spectra and temperature variances agree remarkably well while in the upper stratosphere ECMWF tends to overestimate Kelvin wave components. Gravity wave variances are partly reproduced by ECMWF but have a significant low-bias. For the examples of a QBO westerly phase (October–December 2004) and a QBO easterly phase (November/December 2005, period of the SCOUT-O3 tropical aircraft campaign in Darwin/Australia) in the lower stratosphere we find qualitatively good agreement between SABER and ECMWF in the longitude-time distribution of Kelvin, Rossby ( n =1), and Rossby-gravity waves.