Articles | Volume 9, issue 2
Geosci. Model Dev., 9, 799–822, 2016
https://doi.org/10.5194/gmd-9-799-2016
Geosci. Model Dev., 9, 799–822, 2016
https://doi.org/10.5194/gmd-9-799-2016

Development and technical paper 26 Feb 2016

Development and technical paper | 26 Feb 2016

The description and validation of the computationally Efficient CH4–CO–OH (ECCOHv1.01) chemistry module for 3-D model applications

Yasin F. Elshorbany1,2, Bryan N. Duncan1, Sarah A. Strode1,3, James S. Wang1,3, and Jules Kouatchou1,4 Yasin F. Elshorbany et al.
  • 1NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
  • 2Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland, USA
  • 3Universities Space Research Association, Columbia, Maryland, USA
  • 4Science Systems and Applications Inc., Lanham, Maryland, USA

Abstract. We present the Efficient CH4–CO–OH (ECCOH) chemistry module that allows for the simulation of the methane, carbon monoxide, and hydroxyl radical (CH4–CO–OH) system, within a chemistry climate model, carbon cycle model, or Earth system model. The computational efficiency of the module allows many multi-decadal sensitivity simulations of the CH4–CO–OH system, which primarily determines the global atmospheric oxidizing capacity. This capability is important for capturing the nonlinear feedbacks of the CH4–CO–OH system and understanding the perturbations to methane, CO, and OH, and the concomitant impacts on climate. We implemented the ECCOH chemistry module in the NASA GEOS-5 atmospheric global circulation model (AGCM), performed multiple sensitivity simulations of the CH4–CO–OH system over 2 decades, and evaluated the model output with surface and satellite data sets of methane and CO. The favorable comparison of output from the ECCOH chemistry module (as configured in the GEOS-5 AGCM) with observations demonstrates the fidelity of the module for use in scientific research.

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Short summary
The ECCOH (pronounced "echo") chemistry module interactively simulates the photochemistry of the CH4–CO–OH system within a chemistry climate model, carbon cycle model, or Earth system model. The computational efficiency of the module allows many multi-decadal sensitivity simulations of the CH4–CO–OH system. This capability is important for capturing nonlinear feedbacks of the CH4–CO–OH system and understanding the perturbations to methane, CO, and OH and the concomitant climate impacts.