B24. Atmospheric Chemistry in E3SM



Poster TitleAtmospheric Chemistry in E3SM
First AuthorPhilip Cameron-Smith (Unlicensed)
Topicatmospheric model development
AffiliationNGD-atm
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Title

Atmospheric Chemistry in E3SM

Authors

Philip Cameron-Smith (Unlicensed)Michael J PratherQi Tang

Abstract

Atmospheric chemistry is the dominant process controlling the stratospheric temperature profile and setting the concentrations and distributions of most of the GHGs [including methane (CH4), ozone (O3), nitrous oxide (N2O), and halogenated species (eg, CFCs)]. Interactive stratospheric ozone was incorporated into E3SMv1, but tropospheric species and all other stratospheric species we specified by monthly-mean input files (so E3SM had to depend on other modeling centers to calculate GHG and oxidant concentrations from emission scenarios).  Hence, we are implementing the UC Irvine chemistry mechanism (32 species) to address the known limitations of our super-fast mechanism in E3SM. In the stratosphere, this chemistry will include the new Linoz v3, which simulates the stratospheric species O3, N2O, NOY and CH4. This will provide E3SM with: (1) the capability to simulate CH4, (2) improved simulation of oxidants for production of aerosols (sulfate, nitrate, and SOAs), (3) improved O3 concentrations, especially in polluted regions, (4) simulation of important GHGs in the stratosphere (CH4 & N2O), which is critical to simulating the climate impact of their changing emissions, and (5) tracer-based diagnostics of the tropopause, ITCZ, and stratosphere-troposphere airmass exchange. 

We will present the behavior of stratospheric ozone in the E3SMv1 simulations, the capabilities of the new chemistry mechanism we are adding, and the value of the diagnostic tracers we are adding.