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A Comparison of Stratospheric Gravity Waves in a High-Resolution General Circulation Model with 3-D Satellite Observations
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  • Haruka Okui,
  • Corwin James Wright,
  • Neil P Hindley,
  • Emily J Lear,
  • Kaoru Sato
Haruka Okui
The University of Tokyo

Corresponding Author:[email protected]

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Corwin James Wright
University of Bath
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Neil P Hindley
University of Bath
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Emily J Lear
University of Bath
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Kaoru Sato
The University of Tokyo
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Abstract

Atmospheric gravity waves (GWs) play a key role in determining the thermodynamical structure of the Earth’s middle atmosphere. Despite the small spatial and temporal scales of these waves, a few high-top general circulation models (GCMs) that can resolve them explicitly have recently become available. This study compares global GW characteristics simulated in one such GCM, the Japanese Atmospheric GCM for Upper-Atmosphere Research (JAGUAR), with those derived from three-dimensional (3-D) temperatures observed by the Atmospheric Infrared Sounder (AIRS) aboard NASA’s Aqua satellite. The target period is from 15 December 2018 to 8 January 2019, including the onset of a major sudden stratospheric warming (SSW). The 3-D Stockwell transform method is used for GW spectral analysis. The amplitudes and momentum fluxes of GWs in JAGUAR are generally in good quantitative agreement with those in the AIRS observations in both magnitude and distribution. As the SSW event progressed, the GW amplitudes and eastward momentum flux increased at low latitudes in the summer hemisphere in both the model and observation datasets. Case studies demonstrate that the model is able to reproduce comparable wave events to those in the AIRS observations with some differences, especially noticeable at low latitudes in the summer hemisphere. Through a comparison between the model results with and without the AIRS observational filter applied, it is suggested that the amplitudes of GWs near the exits and entrances of eastward jet streaks are underestimated in AIRS observations.
07 Mar 2023Submitted to ESS Open Archive
09 Mar 2023Published in ESS Open Archive