Wang Ningchao, Qian Liying, Yue Jia, Wang Wenbin, Mlynczak Martin G, Russell James M
Center for Atmospheric Sciences Hampton University Hampton VA USA.
High Altitude Observatory National Center for Atmospheric Research Boulder CO USA.
J Geophys Res Atmos. 2022 Feb 27;127(4):e2021JD035666. doi: 10.1029/2021JD035666. Epub 2022 Feb 22.
In the mesosphere and lower thermosphere (MLT) region, residual circulations driven by gravity wave breaking and dissipation significantly impact constituent distribution and the height and temperature of the mesopause. The distribution of CO can be used as a proxy for the residual circulations. Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) CO volume mixing ratio (VMR) and temperature measurements from 2003 to 2020 are used to study the monthly climatology of MLT residual circulations and the mesopause height. Our analyses show that (a) mesopause height strongly correlates with the CO VMR vertical gradient during solstices; (b) mesopause height has a discontinuity at midlatitude in the summer hemisphere, with a lower mesopause height at mid-to-high latitudes as a result of adiabatic cooling driven by strong adiabatic upwelling; (c) the residual circulations have strong seasonal variations at mid-to-high latitudes, but they are more uniform at low latitudes; and (d) the interannual variability of the residual circulations and mesopause height is larger in the Southern Hemisphere (SH; 4-5 km) than in the Northern Hemisphere (NH; 0.5-1 km).
在中间层和低热层（MLT）区域，由重力波破碎和耗散驱动的剩余环流对成分分布以及中间层顶的高度和温度有显著影响。一氧化碳（CO）的分布可作为剩余环流的替代指标。利用2003年至2020年宽带发射辐射测量大气（SABER）的一氧化碳体积混合比（VMR）和温度测量数据，研究了MLT剩余环流和中间层顶高度的月气候学特征。我们的分析表明：（a）在至日期间，中间层顶高度与CO VMR垂直梯度密切相关；（b）在夏季半球的中纬度地区，中间层顶高度存在间断，由于强烈的绝热上升流驱动的绝热冷却，中高纬度地区的中间层顶高度较低；（c）剩余环流在中高纬度地区有强烈的季节变化，但在低纬度地区更为均匀；（d）剩余环流和中间层顶高度在南半球（SH；4 - 5千米）的年际变率比北半球（NH；0.5 - 1千米）更大。
