A remarkable correlation between short period gravity waves and semiannual oscillation of the zonal wind in the equatorial mesopause region
A remarkable correlation between short period gravity waves and semiannual oscillation of the zonal wind in the equatorial mesopause region
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DOI：
10.5194/angeo-30-703-2012
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发表时间：
2012-04
影响因子：
1.9
通讯作者：
N. Rao;T. Tsuda;Y. Kawatani
中科院分区：
文献类型：
--
作者：
N. Rao;T. Tsuda;Y. Kawatani
抽象的。利用2004-2010年Pameungpeuk（南7.4°，东107.4°）的中频（MF）雷达观测数据，研究了赤道中层顶区域纬向风的变化和短周期（20-120分钟）重力波（GW）的水平风速变化。纬向风表现出明显的半年振荡（称为中层半年振荡，MSAO），春分时有西风，至日时有东风。此外，2008年和2009年三月春分期间西风较大。短周期GW方差也显示出半年振荡，春分期间活动增强。 2008-2010年，纬向风与短周期重力波变化之间存在良好的相关性，在重力波活动增强期间，风向为西向。然而，这种相关性在 2004 年至 2006 年期间不太明显。另一方面，长周期（10-20 小时）GW 方差在整个观察期间并未显示出这种相关性。
Abstract. The variability of zonal winds and the horizontal wind velocity variance of short period (20–120 min) gravity waves (GWs) in the equatorial mesopause region are studied using medium frequency (MF) radar observations from Pameungpeuk (7.4° S, 107.4° E) during 2004–2010. The zonal winds display a distinct semiannual oscillation (called mesospheric semiannual oscillation, MSAO), with westward winds during equinoxes and eastward winds during solstices. Furthermore, the westward winds during March equinox are larger during 2008 and 2009. The short period GW variance also shows a semiannual oscillation with enhanced activity during equinoxes. A good correlation is observed between the zonal winds and the short period GW variance from 2008–2010, with the winds being westward during the times of enhanced GW activity. Such a correlation, however, is less obvious during 2004–2006. The long period (10–20 h) GW variance, on the other hand, does not show such a correlation throughout the observation period.