16:30 〜 16:45
[MIS13-05] 気象雷モデルを用いた雷頻度の将来変化解析
キーワード：雷、数値シミュレーション、将来予測
Future changes to the frequency of lightning can have profound impacts on a wide range of energy sectors. However, previous studies often rely on environmental proxies such as atmospheric instability, cloud top height, and convective precipitation from relatively coarse climate simulations to estimate lightning, which may not be applicable for future climates. Recent supercomputing improvements have allowed climate simulations to explicitly simulate ice distributions within convective clouds, enabling better empirical relationships to be formulated in reproducing observed lightning frequencies. Despite this, many uncertainties remain, particularly since no previous studies have examined future changes by explicitly simulating lightning in climate models.
In this study, we examine changes to lightning frequency on convective-permitting scales using the Scalable Computing for Advanced Library and Environment (SCALE; Sato et al. 2015, Nishizawa et al. 2015) coupled with an explicit lightning model (Sato et al. 2019). Spatial-temporal precipitation and lightning distribution was first confirmed to be well-reproduced by SCALE. For future changes, the pseudo-global warming approach was applied to a high lightning activity event in the Kanto region in eastern Japan using three different warming scenarios. Analysis reveals that despite large increases in instability in the form of convective available potential energy and marginal increases in precipitation in the future, deceased lightning frequencies are depicted in the near-future and end-of-century projections using the lightning model. Additionally, using a lightning diagnostic scheme introduced by McCaul et al. (2009) also depicts a decrease in lightning frequencies, though not to the extent of the lightning model. These changes were primarily attributed to the changes in the vertical structure of the charge separation rate and the charge density, in addition to less ice in the future, suggesting an environment less favorable for lightning formation.
In this study, we examine changes to lightning frequency on convective-permitting scales using the Scalable Computing for Advanced Library and Environment (SCALE; Sato et al. 2015, Nishizawa et al. 2015) coupled with an explicit lightning model (Sato et al. 2019). Spatial-temporal precipitation and lightning distribution was first confirmed to be well-reproduced by SCALE. For future changes, the pseudo-global warming approach was applied to a high lightning activity event in the Kanto region in eastern Japan using three different warming scenarios. Analysis reveals that despite large increases in instability in the form of convective available potential energy and marginal increases in precipitation in the future, deceased lightning frequencies are depicted in the near-future and end-of-century projections using the lightning model. Additionally, using a lightning diagnostic scheme introduced by McCaul et al. (2009) also depicts a decrease in lightning frequencies, though not to the extent of the lightning model. These changes were primarily attributed to the changes in the vertical structure of the charge separation rate and the charge density, in addition to less ice in the future, suggesting an environment less favorable for lightning formation.