ALBERT

Description: Extreme weather events caused by tropical and extratropical cyclones have destructive impacts on infrastructure, society, and environment. 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 the occurrence of severe weather. 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 [1] 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 [2,3], rapid intensification of tropical cyclones [4], and heavy rainfall causing floods and flash floods [5,6] tend to follow arrivals of solar wind high-speed streams from coronal holes. To further support these results, we use various data sets in the superposed epoch analysis of the occurrence of severe weather, including heavy rainfall events and tornado outbreaks, in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere system. [1] Chen T.-C., et al., J. Atmos. Sci. 75, 2425–2443. doi:10.1175/JAS-D-17-0221.1 [2] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys. 149, 219–231. doi:10.1016/j.jastp.2016.04.002 [3] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys. 171, 94–10, 2018. doi:10.1016/j.jastp.2017.07.023 [4] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys. 183, 36-60, 2019. doi:10.1016/j.jastp.2018.12.009 [5] Prikryl P., et al., Ann. Geophys. 39 (4), 769–93, 2021. doi:10.5194/angeo-39-769-2021 [6] Prikryl P., et al., Atmosphere 12 (9), 2021. doi:10.3390/atmos12091186.