The summer circulation of the arctic stratosphere below 30 km

Abstract

Abstract The summer circulation of the arctic stratosphere is examined in the light of climatological data and daily synoptic analysis. The Ferrel westerlies are shown to extend to about 20 km (50 mb) immediately above the jet axis. The middle stratospheric easterlies above them descend to 15 km at the pole in midsummer. The easterlies flow round the flanks of a flat‐centred anticyclone near the pole, and are almost devoid of perturbations. The lower stratosphere (tropopause to 20 km) has a disturbed thermal regime due to vertical motion associated with waves in the Ferrel westerlies or with cold lows within the westerly ring.