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DOI | 10.5194/acp-22-7861-2022 |
Suppressed migrating diurnal tides in the mesosphere and lower thermosphere region during El Nino in northern winter and its possible mechanism | |
Cen, Yetao; Yang, Chengyun; Li, Tao; Russell, James M., III; Dou, Xiankang | |
发表日期 | 2022 |
ISSN | 1680-7316 |
EISSN | 1680-7324 |
起始页码 | 7861 |
结束页码 | 7874 |
卷号 | 22期号:12页码:14 |
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 similar to 10% during El Nino 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 Nino 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 Nino 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 similar to 0-16 km and 35 degrees S-35 degrees N) during El Nino 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 Nino winter. This tide-GW interaction could be a dominant mechanism for DW1 response in the MLT to El Nino. During El Nino 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. |
学科领域 | Environmental Sciences; Meteorology & Atmospheric Sciences |
语种 | 英语 |
WOS研究方向 | Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences |
WOS记录号 | WOS:000812173400001 |
来源期刊 | ATMOSPHERIC CHEMISTRY AND PHYSICS |
文献类型 | 期刊论文 |
条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/273017 |
作者单位 | Chinese Academy of Sciences; University of Science & Technology of China, CAS; Chinese Academy of Sciences; University of Science & Technology of China, CAS; Chinese Academy of Sciences; University of Science & Technology of China, CAS; Wuhan University; Hampton University |
推荐引用方式 GB/T 7714 | Cen, Yetao,Yang, Chengyun,Li, Tao,et al. Suppressed migrating diurnal tides in the mesosphere and lower thermosphere region during El Nino in northern winter and its possible mechanism[J],2022,22(12):14. |
APA | Cen, Yetao,Yang, Chengyun,Li, Tao,Russell, James M., III,&Dou, Xiankang.(2022).Suppressed migrating diurnal tides in the mesosphere and lower thermosphere region during El Nino in northern winter and its possible mechanism.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(12),14. |
MLA | Cen, Yetao,et al."Suppressed migrating diurnal tides in the mesosphere and lower thermosphere region during El Nino in northern winter and its possible mechanism".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.12(2022):14. |
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