Troposphere-Stratosphere Feedback Mechanism: Stratospheric Warming and Its Effect on the Polar Energy Budget and the Tropospheric Circulation

Abstract

The large increase in polar stratospheric temperatures during sudden warming events results in an enhancement in the downward longwave radiation flux emitted by the stratosphere. It is shown that the enhancement in the downward longwave flux has an appreciable warming effect on the winter polar troposphere and surface and also leads to a reduction in the tropospheric available potential energy. The results of the previous analyses indicate that the stratospheric warming is initiated by the upward flux of geopotential energy from the troposphere. Based on these results it is suggested that the planetary-scale tropospheric waves accomplish part of the poleward transport of heat in the troposphere indirectly through the sudden warming phenomenon. It is also shown that roughly 80?90% of the downward longwave radiative flux emitted by ozone in the polar stratosphere reaches the.polar surface and the importance of this downward ozone flux to the polar surface energy budget is qualitatively discussed. The results indicate the importance of the stratospheric circulation and radiative energy transfer to the tropospheric circulation and energy budget.