日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM09] Vertical coupling in the atmosphere and Ionosphere

2019年5月29日(水) 10:45 〜 12:15 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:Liu Huixin(九州大学理学研究院地球惑星科学専攻 九州大学宙空環境研究センター)、Chang Loren(Institute of Space Science, National Central University)、大塚 雄一(名古屋大学宇宙地球環境研究所)

[PEM09-P06] Solar wind influence on tropical cyclones mediated by atmospheric gravity waves

*Paul Prikryl1,2Iurii Cherniak3Irina Zakharenkova4,5James M. Weygand6Bharat S. R. Kunduri7 (1.Physics Department, University of New Brunswick, Fredericton, NB, Canada、2.Geomagnetic Laboratory, Natural Resources Canada, Ottawa, ON, Canada、3.COSMIC Program Office, University Corporation for Atmospheric Research, Boulder, CO, USA、4.West Department of IZMIRAN, Kaliningrad, Russia、5.University of Warmia and Mazury in Olsztyn, Poland、6.Earth Planetary and Space Sciences, University of California, Los Angeles, CA, USA、7.Bradley Dept. of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, USA)

キーワード:Solar wind-magnetosphere-ionosphere-atmosphere coupling, High-speed solar wind stream, Atmospheric gravity wave, Extratropical and tropical cyclones

Solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system generates medium- and large-scale atmospheric gravity waves (AGWs) propagating globally from sources in the lower thermosphere at high latitudes. The AGWs propagate globally [1,2] upward and downward, are observed in the ionosphere as traveling ionospheric disturbances [3], can be ducted in lower atmosphere over long distances and reach troposphere. At the reflection point in the troposphere they can trigger moist instabilities to initiate convective bursts, with the latent heat release leading to intensification of storms [4]. In the follow-up studies [5,6,7] it was shown that explosive extratropical cyclones and rapid intensification of tropical cyclones tend to follow arrivals of solar wind high-speed streams (HSS) and/or interplanetary coronal mass ejections (ICMEs). The coupling of solar wind to MIA is most intense during the arrivals of co-rotating interaction regions (CIRs) and/or interplanetary shocks at the leading edges of HSSs and ICMEs when the amplitudes of aurorally-generated AGWs are largest. Ray tracing of AGWs in a model atmosphere show that they can reach tropical cyclones. Spiral gravity waves in typhoons were observed and simulated to propagate radially outward from the typhoon core [8]. The spectra of waves in surface pressure and surface wind measured by the Impacts of Typhoons on the Ocean in the Pacific (ITOP) buoy during the nearby passages of intense typhoons are similar to those of incoming aurorally-generated AGWs. It is suggested that the interaction of aurorally-generated gravity waves with the tropical cyclone vortex and the inner primary eyewall plays a role in the intensification process.

[1] Mayr H.G., et al., J. Geophys. Res., 89, 10929–10959, 1984.
[2] Prikryl P., et al., Ann. Geophys., 23, 401-417, 2005. doi:10.5194/angeo-23-401-2005
[3] Cherniak Iu., Zakharenkova I., Space Weather, 16, 2018. https://doi.org/10.1029/2018SW001869.
[4] Prikryl P., et al., Ann. Geophys. 27, 31–57, 2009. https://doi.org/10.5194/angeo-27-31-2009.
[5] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys., 149, 219–231, 2016.
[6] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys., 171, 94–110, 2018.
[7] Prikryl P., et al., J. Atmos. Sol.-Terr. Phys., 183, 36-60, https://doi.org/10.1016/j.jastp.2018.12.009.
[8] Nolan D.S., Zhang J.A., Geophys. Res. Lett., 44, 3924–3931, 2017. doi:10.1002/2017GL073572