Space Climate 7:

Space Climate Symposium on July 8-11 , 2019

Space Climate 7 Meeting Abstract

Solar wind imprint on gravity waves and atmospheric circulation

Paul Prikryl (University of New Brunswick)

More than four decades have passed since the discovery by Wilcox et al. (1973) of a relationship between solar wind magnetic sector boundary structure and the mid-latitude upper-tropospheric vorticity/circulation. These results have been confirmed and several physical mechanisms to explain them proposed. The coupling of solar wind to magnetosphere - ionosphere - atmosphere (MIA) system generates internal atmospheric gravity waves propagating upward and downward from lower thermosphere sources at high latitudes. The gravity waves can be ducted in the lower atmosphere over long distances and reach troposphere. Despite significantly reduced wave amplitude, but subject to amplification upon over-reflection in the upper troposphere, the gravity waves can trigger moist instabilities and initiate convective bursts. The released latent heat is a known source of energy leading to intensification of extratropical storms and convective bursts have been linked to rapid intensification of tropical cyclones. Recent studies have shown that explosive extratropical cyclones and rapid intensification of tropical cyclones tend to follow arrivals of solar wind high-speed streams and interplanetary coronal mass ejections. The solar wind MIA coupling, including solar wind Alfvén wave coupling, is most intense during the arrivals of co-rotating interaction regions and interplanetary shocks at the leading edge of high-speed solar wind when the amplitudes of aurorally-generated gravity waves are largest. When these gravity waves trigger moist instabilities in extratropical and tropical cyclones the intensification of cyclones leads to enhanced atmospheric circulation.

Mode of presentation: oral (Need to be confirmed by the SOC)

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