10:45 AM - 12:15 PM
[PEM12-P31] Research on atmospheric gravity waves associated with Extreme Weather Phenomenon (Heavy Rainfall in August 2021)
Keywords:Atmospheric gravity waves
Atmospheric gravity waves are generated in the troposphere during phenomena such as convection and latent heat heating. In this study, we focus on gravity waves excited by extreme weather events (heavy rainfall in August 2021) and analyze the excitation and vertical propagation processes of gravity waves in the troposphere and stratosphere. The analysis was conducted using objective reanalysis data (horizontal resolution: 5 km / temporal resolution: 1 hour) from the JMA's local model (asuca) and observation data from the AIRS onboard the Aqua satellite. The analysis period and coverage are August 2021 (especially during the heavy rainfall period from 12 to 16 August) and over Japan (especially from 30 degrees to 40 degrees N latitude and 120 degrees to 140 degrees E longitude), respectively.
Comparing the brightness temperature disturbance in the satellite observation data and the temperature disturbance in the reanalysis data, stripe-shaped gravity waves are seen from the East China Sea to Kyushu, respectively, and their positions and horizontal wavelengths seem to be relatively consistent. Comparing ΔNBE, a measure of the non-equilibrium component of the jet stream obtained from the parameters of the reanalysis data, with the temperature disturbance, it appears that gravity waves are generated from areas with large gradients in geopotential height, respectively.
The comparative agreement between the reanalysis data and the observed data, as well as the supposed agreement between the ΔNBE and the temperature disturbance, suggest that the observed gravity waves may be of frontal origin.
Comparing the brightness temperature disturbance in the satellite observation data and the temperature disturbance in the reanalysis data, stripe-shaped gravity waves are seen from the East China Sea to Kyushu, respectively, and their positions and horizontal wavelengths seem to be relatively consistent. Comparing ΔNBE, a measure of the non-equilibrium component of the jet stream obtained from the parameters of the reanalysis data, with the temperature disturbance, it appears that gravity waves are generated from areas with large gradients in geopotential height, respectively.
The comparative agreement between the reanalysis data and the observed data, as well as the supposed agreement between the ΔNBE and the temperature disturbance, suggest that the observed gravity waves may be of frontal origin.