An observational study of the Northern Hemisphere extratropical summertime general circulation.

Abstract

The three-dimensional structure of the extratropical Northern Hemisphere summertime general circulation is documented by making use of twice-daily operational analyses at nine pressure levels (1000-100 mb) for 12 summers (1966-77). Two distinct regimes of standing waves quite unlike the wintertime standing waves appear: a subtropical regime which is clearly a monsoonal response to thermal forcing, and a higher latitude regime in which the standing waves are of smaller scale and much weaker than in winter and tend to be equivalent barotropic in structure with almost no vertical tilt in the mid- and upper troposphere.-from Author