Response Of Summer Stratospheric Temperature And Circulation In The North Hemisphere To 11-Yr Solar Cycle And Its Mechanism

Meteorological statistical methods and BCC-RAD model are used to study the response characteristics of summer stratospheric temperature and circulation in the North Hemisphere to the 11 year solar cycle and its mechanism. The discussions are mainly based on ERA-Interim, JRA-55 and MERRA monthly reanalysis dataset during 1979 to 2013, and solar spectrum data from 2004 to 2010. And the results can be summarized as follows:(1) Zonal mean temperature in summer increases as the height increase at stratosphere, and reaches the peak value at stratopause; temperature and solar cycle shows the significant correlation; in the 11 year solar cycle, compared to the solar weak regime, temperature in both lower and upper stratosphere at equator and polar stratopause exhibit the significant enhancement in solar strong regime, respectively, 1.2K,1.6K and 3.2K.(2) For the summer stratospheric circulation in the Northern Hemisphere, it mainly indicates prevailing easterlies and weaken meridional cycle, which shows dynamic activity weaken, radiation activity takes main role. The correlation between zonal wind is remarkable; compared to the solar weak regime, the eastern wind at middle latitude is weakened, ascending motion of meridional cycle is weaken at three key parts.(3) Heating rate impacts temperature in solar cycle. Both ozone concentration and radiance can influence heating rate. In the 11 year solar cycle, compared to the weaken regime, the ultraviolet radiation indicates the strong positive anomaly as 7% in the solar strong regime, which results the ozone heating rate showing the positive anomaly in the whole stratosphere, and increases as the height increase. Ozone concentration shows negative anomaly in upper stratosphere, and negative in lower stratosphere, which leads to the similar pattern of ozone heating rate with the height migration. As for ozone heating rate, ultraviolet radiation takes main role in upper stratosphere, ozone takes main role in lower stratosphere. The area of positive ozone heating rate is same as temperature.(4) Solar cycle impacts on zonal wind through thermal wind principle, the horizontal gradient of temperature is in direct proportion to the vertical gradient of zonal wind; compared to the solar weaken regime, the temperature warming at polar stratopause caused by the weaken ascending motion of meridional circulation which leads to the adiabatic cooling decreased, ozone concentration adding with the ascending BD circulation weakened finally caused the temperature changing in lower stratosphere.