Climatic distribution and long-term variations of optical instability of the Earth’s atmosphere (OIEA), eddy activity of the atmosphere were studied by data of NCEP/NCAR Reanalysis. In the lower and middle troposphere the level of optical instability depends on the eddy activity and horizontal temperature gradients in the polar front area and at the “ocean–continent” boundary. In the upper troposphere and in the tropic regions the temperature variations are associated with changes in temperature occurring during vertical motions. In the lower stratosphere OIEA variations are caused by changes of the polar eddy and adiabatic changes of temperature. In the lower troposphere, variations of the OIEA and eddy activity are most closely connected in tropics and subtropics: in the South of Asia, in Africa, and South America. Some of favorable (from the viewpoint of astroclimate) regions in the Southern Hemisphere (South Africa, South America) in wintertime fall into the area of positive trends of OIEA. Variations of the OIEA and eddy activity might be caused by changes in the general circulation of the atmosphere, in particular, by strengthening the circum-Antarctic depression.
astroclimate, atmospheric circulation, vortex activity