EGU2020-4968
https://doi.org/10.5194/egusphere-egu2020-4968
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Severe weather in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere system

Paul Prikryl1,2, Vojto Rušin3, Pavel Šťastný4, Maroš Turňa4, and Martina Zeleňáková5
Paul Prikryl et al.
  • 1University of New Brunswick, Physics Department, Ottawa, Canada (paul.prikryl@unb.ca)
  • 2Geomagnetic Laboratory, Natural Resources Canada, Ottawa, ON, Canada
  • 3Astronomical Institute, Slovak Academy of Sciences, Tatranská Lomnica, Slovakia
  • 4Slovak Hydrometeorological Institute, Bratislava, Slovakia
  • 5Technical University of Košice, Košice, Slovakia

Tropical and extratropical cyclones can intensify into the most destructive weather systems that have significant societal and economic impacts. Rapid intensification of such weather systems has been examined in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system. It has been shown [1,2] that explosive extratropical cyclones and rapid intensification of tropical cyclones tend to follow arrivals of high-speed solar wind when the MIA coupling is strongest. The coupling generates atmospheric gravity waves (AGWs) that propagate from the high-latitude lower thermosphere both upward and downward [3,4]. In the upper atmosphere, AGWs are observed as traveling ionospheric disturbances. In the lower atmosphere, they can reach the troposphere and be ducted [4] to low latitudes. Despite significantly reduced wave amplitude, but subject to amplification upon over-reflection in the upper troposphere, these AGWs can trigger/release moist instabilities leading to convection and latent heat release, which is the energy driving the storms. The release of conditional symmetric instability is known to initiate slantwise convection producing rain/snow bands in extratropical cyclones. Severe weather, including severe winter storms, heavy snowfall and rainfall events, have been examined in the context of MIA coupling [5]. The results indicate a tendency of significant weather events, particularly if caused by low pressure systems in winter, to follow arrivals of solar wind high-speed streams from coronal holes. In the present paper we review the published results and provide further evidence to support them. This includes the occurrence of heavy rainfall events and flash floods, as well as the rapid intensification of recent hurricanes and typhoons, with the goal to identify sources of AGWs at high latitudes that may play a role in triggering convective bursts potentially leading to such events.

[1] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys., 149, 219–231, 2016.

[2] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys., 183, 36–60, 2019.

[3] Prikryl P., et al., Ann. Geophys., 23, 401–417, 2005.

[4] Mayr H.G., et al., J. Geophys. Res., 89, 10929–10959, 1984.

[5] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys., 171, 94–110, 2018.

How to cite: Prikryl, P., Rušin, V., Šťastný, P., Turňa, M., and Zeleňáková, M.: Severe weather in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere system, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4968, https://doi.org/10.5194/egusphere-egu2020-4968, 2020

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Presentation version 5 – uploaded on 23 May 2020 , no comments
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  • CC1: Comment on EGU2020-4968, Maria-Carmen Llasat, 04 May 2020

    Thank you very much for your presentation. How do you explain this solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system? Why the coupling generates atmospheric gravity waves (AGWs)?

    • AC1: Reply to CC1, Paul Prikryl, 04 May 2020

      Thank you for your question. To answer I can refer you to our paper (Part 2) from 2009 https://www.ann-geophys.net/27/31/2009/, where we briefly reviewed this topic in Sections 1.1. In Section 3, we showed that these AGWs can propagate both upward and downward, which has been well known for a long time (see, reference [4] in our abstract). In Section 4, discussed two events when AGWs/TIDs were observed in the ionosphere.

      Maybe a quick answer to your question: The solar wind, by a process called magnetic reconnection, couples to the Earth’s magnetosphere, drives ionospheric currents including the auroral electrojets. The solar wind energy is thus channeled to the auroral ovals and deposited in the upper atmosphere, much of it in the form of Joule heating. On time scales from tens of minutes to a few hours, pulses of auroral electrojets and ionospheric convection generate AGWs.  Sources of AGWs in the high-latitude lower thermosphere have been known since 1970s – see, our slide 19 for references.

  • CC2: Comment on EGU2020-4968, Maria-Carmen Llasat, 05 May 2020

    Dear Dr. Prikryl

    Thank you very much for your detailed answer!

    Sincerely Yours

    Maria Carmen

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