Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.509 IF 5.509
  • IF 5-year value: 5.689 IF 5-year 5.689
  • CiteScore value: 5.44 CiteScore 5.44
  • SNIP value: 1.519 SNIP 1.519
  • SJR value: 3.032 SJR 3.032
  • IPP value: 5.37 IPP 5.37
  • h5-index value: 86 h5-index 86
  • Scimago H index value: 161 Scimago H index 161
Volume 18, issue 15 | Copyright
Atmos. Chem. Phys., 18, 10955-10971, 2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 06 Aug 2018

Research article | 06 Aug 2018

Forecasting carbon monoxide on a global scale for the ATom-1 aircraft mission: insights from airborne and satellite observations and modeling

Sarah A. Strode1,2, Junhua Liu1,2, Leslie Lait2,3, Róisín Commane4,a, Bruce Daube4, Steven Wofsy4, Austin Conaty2,5, Paul Newman2, and Michael Prather6 Sarah A. Strode et al.
  • 1Universities Space Research Association, Columbia, MD, USA
  • 2NASA GSFC, Greenbelt, MD, USA
  • 3Morgan State University, Baltimore, MD, USA
  • 4Harvard University, Cambridge, MA, USA
  • 5SSAI, Greenbelt, MD, USA
  • 6University of California, Irvine, CA, USA
  • anow at: Columbia University, New York, NY, USA

Abstract. The first phase of the Atmospheric Tomography Mission (ATom-1) took place in July–August 2016 and included flights above the remote Pacific and Atlantic oceans. Sampling of atmospheric constituents during these flights is designed to provide new insights into the chemical reactivity and processes of the remote atmosphere and how these processes are affected by anthropogenic emissions. Model simulations provide a valuable tool for interpreting these measurements and understanding the origin of the observed trace gases and aerosols, so it is important to quantify model performance. Goddard Earth Observing System Model version 5 (GEOS-5) forecasts and analyses show considerable skill in predicting and simulating the CO distribution and the timing of CO enhancements observed during the ATom-1 aircraft mission. We use GEOS-5's tagged tracers for CO to assess the contribution of different emission sources to the regions sampled by ATom-1 to elucidate the dominant anthropogenic influences on different parts of the remote atmosphere. We find a dominant contribution from non-biomass-burning sources along the ATom transects except over the tropical Atlantic, where African biomass burning makes a large contribution to the CO concentration. One of the goals of ATom is to provide a chemical climatology over the oceans, so it is important to consider whether August 2016 was representative of typical boreal summer conditions. Using satellite observations of 700hPa and column CO from the Measurement of Pollution in the Troposphere (MOPITT) instrument, 215hPaCO from the Microwave Limb Sounder (MLS), and aerosol optical thickness from the Moderate Resolution Imaging Spectroradiometer (MODIS), we find that CO concentrations and aerosol optical thickness in August 2016 were within the observed range of the satellite observations but below the decadal median for many of the regions sampled. This suggests that the ATom-1 measurements may represent relatively clean but not exceptional conditions for lower-tropospheric CO.

Download & links
Publications Copernicus
Short summary
The GEOS-5 atmospheric model provided forecasts for the Atmospheric Tomography Mission (ATom). GEOS-5 shows skill in simulating the carbon monoxide (CO) measured in ATom-1. African fires contribute to high CO over the tropical Atlantic, but non-fire sources are the main contributors elsewhere. ATom aims to provide a chemical climatology, so we consider whether ATom-1 occurred during a typical summer month. Satellite observations suggest ATom-1 occurred in a clean but not exceptional month.
The GEOS-5 atmospheric model provided forecasts for the Atmospheric Tomography Mission (ATom)....