Role of the equatorial Kelvin wave in stratosphere‐troposphere exchange in a general circulation model
Role of the equatorial Kelvin wave in stratosphere‐troposphere exchange in a general circulation model
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赤道开尔文波在大气环流模型中平流层-对流层交换中的作用
DOI：
10.1029/2000jd000161
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发表时间：
2001
影响因子：
--
通讯作者：
M. Takahashi
中科院分区：
文献类型：
--
作者：
M. Fujiwara;M. Takahashi
本文用一个包含简化的臭氧光化学、真实地形和海表温度季节变化的大气环流模式研究了引起赤道对流层顶附近臭氧和水变化的大尺度扰动。东移的大尺度赤道重力波对赤道对流层顶附近的次分量分布起着主要的调制作用。详细调查了北方夏季印度洋上空的一个病例。该扰动具有对流层顶赤道开尔文波的特征，并伴有对流层中有组织的活跃对流。与该系统的向下位移（和抑制对流）相关联，干燥，富含臭氧的平流层空气向下移动到对流层上部。在相反的阶段，有组织的活跃对流上方的物理和动力过程阻止了平流层下部积聚过多的水。因此，在该系统通过期间，赤道对流层顶周围的干燥得以维持。对4年积分资料的分析表明，这种扰动在北方夏季至秋季在印度洋上空特别活跃。这可能与南亚夏季风环流的发展有关。该模式还模拟了热带对流层臭氧的纬向波一结构，揭示了对流输送对该结构的重要贡献。
Large-scale disturbances which cause the variations of ozone and water around the equatorial tropopause are investigated with a general circulation model incorporating a simplified ozone photochemistry, realistic topography, and seasonal cycle of the sea surface temperature. Eastward moving large-scale equatorial gravity waves are found to be dominant to modulate the minor constituents' distribution around the equatorial tropopause. A case over the Indian Ocean in the northern summer was investigated in detail. The disturbance had the characteristics of the equatorial Kelvin wave at the tropopause level, coupled with organized active convections in the troposphere. Associated with the downward displacement (and suppressed-convection) phase of this system, dry, ozone-rich stratospheric air moved downward into the upper troposphere. At the opposite phase, physical and dynamical processes above the organized active convections prevented the lower stratosphere from accumulating excess water. Thus the dryness around the equatorial tropopause is maintained during the passage of such a system. Analysis of 4-year integration data reveals that such disturbances are especially active over the Indian Ocean during the northern summer through autumn. This is probably related to the development of the summer monsoon circulation over south Asia. This model has also simulated the zonal wave one structure of tropical tropospheric ozone and suggested the important contribution of convective transport to the structure.