[A-AS03] Extreme Events and Mesoscale Weather: Observations and Modeling

[AAS03-P11] Occurrence of heavy precipitation influenced by solar wind high-speed streams

*Paul Prikryl¹, Vojto Rušin² (1.Physics Department University of New Brunswick, 2.Astronomical Institute, Slovak Academy of Sciences)

Keywords:Heavy precipitation, Solar wind coupling to the magnetosphere-ionosphere-atmosphere system, Atmospheric gravity waves, Conditional symmetric instability and slantwise convection

Forecasting extreme weather continues to present challenges. We consider solar wind coupling to the magnetosphere-ionosphere-atmosphere system, mediated by globally propagating aurorally excited atmospheric gravity waves, influencing occurrence of heavy precipitation causing floods and flash floods. While these gravity waves reach the troposphere with attenuated amplitudes, they are subject to amplification when encountering opposing winds and vertical wind shears. They can release conditional symmetric instability leading to slantwise convection, latent heat release, and contributing to intensification of storms. It has been shown that significant weather events, including explosive extratropical cyclones [1,2], rapid intensification of tropical cyclones [3], and heavy rainfall causing floods and flash floods [4,5] tend to occur following arrivals of solar wind high-speed streams from coronal holes. To support these published results, the occurrence of heavy-rainfall-induced floods in Canada, and cool season precipitation events, including extreme freezing rain in the province of New Brunswick, is studied in the context of solar wind. Further evidence is provided by the analysis of high-rate precipitation obtained from a satellite-based precipitation data set. The results show an increase in the high-rate precipitation occurrence following arrivals of high-speed streams.

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[2] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys. 171, 94–10, 2018. doi:10.1016/j.jastp.2017.07.023
[3] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys. 183, 36-60, 2019. doi:10.1016/j.jastp.2018.12.009
[4] Prikryl P., et al., Ann. Geophys. 39(4), 769–93, 2021. doi:10.5194/angeo-39-769-2021
[5] Prikryl P., et al., Atmosphere 12(9), 2021. doi.org/10.3390/atmos12091186