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Title: A Novel Gravity Wave Transport Parametrization for Global Chemistry Climate Models: Description and Validation
Abstract The gravity wave drag parametrization of the Whole Atmosphere Community Climate Model (WACCM) has been modified to include the wave‐driven atmospheric vertical mixing caused by propagating, non‐breaking, gravity waves. The strength of this atmospheric mixing is represented in the model via the “effective wave diffusivity” coefficient (Kwave). UsingKwave, a new total dynamical diffusivity (KDyn) is defined.KDynrepresents the vertical mixing of the atmosphere by both breaking (dissipating) and vertically propagating (non‐dissipating) gravity waves. Here we show that, when the new diffusivity is used, the downward fluxes of Fe and Na between 80 and 100 km largely increase. Larger meteoric ablation injection rates of these metals (within a factor 2 of measurements) can now be used in WACCM, which produce Na and Fe layers in good agreement with lidar observations. Mesospheric CO2is also significantly impacted, with the largest CO2concentration increase occurring between 80 and 90 km, where model‐observations agreement improves. However, in regions where the model overestimates CO2concentration, the new parametrization exacerbates the model bias. The mesospheric cooling simulated by the new parametrization, while needed, is currently too strong almost everywhere. The summer mesopause in both hemispheres becomes too cold by about 30 K compared to observations, but it shifts upward, partially correcting the WACCM low summer mesopause. Our results highlight the far‐reaching implications and the necessity of representing vertically propagating non‐breaking gravity waves in climate models. This novel method of modeling gravity waves contributes to growing evidence that it is time to move away from dissipative‐only gravity wave parametrizations.  more » « less
Award ID(s):
2110422 2029162
PAR ID:
10512773
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Corporate Creator(s):
Editor(s):
Fan, Jiwen
Publisher / Repository:
American Geophysical Union
Date Published:
Journal Name:
Journal of Advances in Modeling Earth Systems
Edition / Version:
1
Volume:
16
Issue:
5
ISSN:
1942-2466
Page Range / eLocation ID:
1-37
Subject(s) / Keyword(s):
wave parameterization, global modeling
Format(s):
Medium: X Size: 9.2 MB Other: pdf/A
Size(s):
9.2 MB
Sponsoring Org:
National Science Foundation
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