对流层气溶胶的直接气候效应对平流层的影响

摘要

The comparison between satellite data and WACCM-3 model simulated results shows that simulated results are well consistent with satellite data in central Africa,the Arabian Peninsula,Indian subconti-nent,and most parts of China,but in south central Africa,Caribbean and Europe,the model results are lower.In short,model results can well reproduce the global distribution of aerosols,but numerical differ-ence exists in some areas. Simulation indicates that changes of stratospheric temperature are neither caused by changes of strato-spheric short-wave radiation nor decided by the changes of long-wave radiation.The changes of strato-spheric temperature are not caused by the tropospheric aerosol effect but the results of dynamic process, and the changes of longwave radiative heating rate are in response to temperature changes and mitigate the change.The process of stratospheric chemical,dynamic and radiation process are tightly coupled together. By comparison,the experiment group A including stratospheric chemical process and experiment group B not including stratospheric chemical process,it shows that the changes of temperature and wind are differ-ent in the tropospheric aerosols direct effect on stratosphere.The stratospheric chemical process is of vital importance on the tropospheric aerosols effects on stratospheric climate.Stratospheric chemical process has different effects in different seasons and in different regions,polar and high-altitude regions are consid-ered to be mostly affected,in addition,stratospheric chemical process also has great influence on the upper stratosphere.The temperature variation can reach 6 K at the most,and zonal wind variation can also reach 12 m/s.The tropospheric aerosols influence the tropospheric radiative balance,tropospheric temperature, atmospheric circulation and EP flux,and changes in EP flux indicate the planetary wave propagation chan-ges. Planetary wave propagation changes make the stratospheric climate change:Stratospheric tempera-ture,and wind field change,stratospheric ozone and radiation and dynamic processes are closely linked and influenced by each other,the temperature and wind changes will influence the concentration of ozone.Po-lar and high-latitude regions are considered to be mostly affected,and the impact on southern high lati-tudes is greater than that on northern high latitudes.The temperature variation can reach 10 K at the most,zonal wind variation can also reach 12 m/s and ozone mixing ratio can decline for 0.8×10 -6 at the most at 20 hPa in the lower Antarctic stratosphere,while in most other areas the temperature change does not exceed 1 K.%通过 WACCM-3模式中气溶胶光学厚度与卫星资料的对比发现，模式可以很好地再现全球气溶胶的主要分布特征，但在一些区域还存在数值上的差异。利用数值试验研究对流层气溶胶的直接气候效应对平流层气候的影响，结果表明：对流层气溶胶对平流层气候有明显影响，平流层化学过程在这一影响中起重要作用，而对流层气溶胶对平流层辐射的影响不是其直接气候效应对平流层影响的主要原因。其机制可能是对流层气溶胶改变对流层的辐射平衡，影响对流层的温度和大气环流，进而影响行星波的上传，使得平流层气候发生变化；影响区域主要位于高纬度和极地地区，南半球的变化比北半球大，温度变化最大达10 K，纬向风变化最大可达12 m／s，臭氧体积分数最多减少0．8×10－6。