17:15 〜 18:45
[AAS10-P08] Effects of ozone on stratosphere-troposphere coupling in the Northern extratropics on subseasonal to seasonal scales
キーワード：成層圏対流圏結合、成層圏オゾン、季節内から季節予測
Modeling and observational studies have reported that the stratosphere can have significant impacts on Northern extratropical surface climate on subseasonal to seasonal (S2S) timescales (e.g. Domeisen et al., 2020). Stratosphere-troposphere (S-T) dynamical coupling has been considered a significant predictability source of surface climate (Baldwin & Dunkerton, 2001; Scaife et al., 2005). Recent work has further suggested that the stratospheric ozone can modulate the S-T dynamical coupling, and therefore it can have an impact on surface climate on S2S timescales (Oehrlein et al., 2020; Friedel et al., 2022). Here we study the importance of interactive ozone chemistry in representing the S-T coupling and Northern extratropical surface climate variability in the boreal winter and spring.
We have developed a simplified linear ozone scheme to represent interactive ozone chemistry, as well as a detailed full-chemistry 3-D model. We performed two climate ensemble simulations using the simplified and full-chemistry interactive chemistry versions of the Meteorological Research Institute Earth-system model Version 3.2 (MRI-ESM3.2). We contrast the two ensemble simulations with interactive ozone chemistry to a specified ozone chemistry (climatological ozone) ensemble simulation to isolate the impacts of interactive ozone on the S-T coupling and surface climate. Both the two interactive ozone simulations similarly show that stronger stratospheric polar vortex mean state and the fewer major sudden stratospheric warming (SSW) events. In addition, the negative phase of the Arctic Oscillation (AO), which is an important mode of atmospheric variability in the Northern extratropics ranging from the surface to the stratosphere, propagates from the stratosphere to the surface more strongly one or two months after the occurrence of major SSWs.
We have developed a simplified linear ozone scheme to represent interactive ozone chemistry, as well as a detailed full-chemistry 3-D model. We performed two climate ensemble simulations using the simplified and full-chemistry interactive chemistry versions of the Meteorological Research Institute Earth-system model Version 3.2 (MRI-ESM3.2). We contrast the two ensemble simulations with interactive ozone chemistry to a specified ozone chemistry (climatological ozone) ensemble simulation to isolate the impacts of interactive ozone on the S-T coupling and surface climate. Both the two interactive ozone simulations similarly show that stronger stratospheric polar vortex mean state and the fewer major sudden stratospheric warming (SSW) events. In addition, the negative phase of the Arctic Oscillation (AO), which is an important mode of atmospheric variability in the Northern extratropics ranging from the surface to the stratosphere, propagates from the stratosphere to the surface more strongly one or two months after the occurrence of major SSWs.