Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.5194/acp-22-7861-2022 |
Suppressed migrating diurnal tides in the mesosphere and lower thermosphere region during El Niño in northern winter and its possible mechanism | |
Yetao Cen, Chengyun Yang, Tao Li, James M. Russell III, and Xiankang Dou | |
2022-06-17 | |
发表期刊 | Atmospheric Chemistry and Physics |
出版年 | 2022 |
英文摘要 | As observed by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER), the migrating diurnal tide (DW1) in the upper mesosphere and lower thermosphere (MLT) region decreased by ∼ 10 % during El Niño in the Northern Hemisphere (NH) winter (December–January–February) from 2002 to 2020. According to the multiple linear regression (MLR) analysis, the linear effects of El Niño on the tropical MLT DW1 are significantly negative in both SABER observations and SD-WACCM (the Specified-Dynamics version of the Whole Atmosphere Community Climate Model) simulations. The DW1 response to El Niño in NH winter is much stronger than its annual mean response. As suggested by SD-WACCM simulation, Hough mode (1, 1) dominates the DW1 tidal variation in the tropical MLT region. The consistency between the (1, 1) mode in the tropopause region and the MLT region and the downward phase progression from 15 to 100 km indicates the direct upward propagation of DW1 from the excitation source in the troposphere. The suppressed DW1 heating rates in the tropical troposphere (averaged over ∼ 0–16 km and 35∘ S–35∘ N) during El Niño winter contribute to the decreased DW1 tide. To evaluate the effect of the gravity waves (GWs) on the tide, the GW forcing is calculated as the GW drag weighted by the phase relation between DW1 GW drag and DW1 wind. The negative GW forcing in the tropical upper mesosphere would significantly suppress the MLT DW1 tide during El Niño winter. This tide–GW interaction could be a dominant mechanism for DW1 response in the MLT to El Niño. During El Niño winter, the increased ratio of the absolute and planetary vorticity (R) suppresses the waveguide and thus the DW1 amplitude in the subtropical mesosphere. However, the effect of the waveguide might play a secondary role due to its relatively weak response. |
领域 | 地球科学 |
URL | 查看原文 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/351713 |
专题 | 地球科学 |
推荐引用方式 GB/T 7714 | Yetao Cen, Chengyun Yang, Tao Li, James M. Russell III, and Xiankang Dou. Suppressed migrating diurnal tides in the mesosphere and lower thermosphere region during El Niño in northern winter and its possible mechanism[J]. Atmospheric Chemistry and Physics,2022. |
APA | Yetao Cen, Chengyun Yang, Tao Li, James M. Russell III, and Xiankang Dou.(2022).Suppressed migrating diurnal tides in the mesosphere and lower thermosphere region during El Niño in northern winter and its possible mechanism.Atmospheric Chemistry and Physics. |
MLA | Yetao Cen, Chengyun Yang, Tao Li, James M. Russell III, and Xiankang Dou."Suppressed migrating diurnal tides in the mesosphere and lower thermosphere region during El Niño in northern winter and its possible mechanism".Atmospheric Chemistry and Physics (2022). |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论