Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 18, 6801-6828, 2018
https://doi.org/10.5194/acp-18-6801-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
16 May 2018
Assessing stratospheric transport in the CMAM30 simulations using ACE-FTS measurements
Felicia Kolonjari1, David A. Plummer2, Kaley A. Walker1, Chris D. Boone3, James W. Elkins4, Michaela I. Hegglin5, Gloria L. Manney6,7, Fred L. Moore8,9, Diane Pendlebury10, Eric A. Ray8,9, Karen H. Rosenlof8, and Gabriele P. Stiller11 1Department of Physics, University of Toronto, Toronto, Canada
2Climate Research Division, Environment and Climate Change Canada, Montreal, Canada
3Department of Chemistry, University of Waterloo, Waterloo, Canada
4Global Monitoring Division, NOAA Earth System Research Laboratory, Boulder, USA
5Department of Meteorology, University of Reading, Reading, UK
6NorthWest Research Associates, Socorro, USA
7Department of Physics, New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA
8Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, USA
9Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, USA
10Air Quality Research Division, Environment and Climate Change Canada, Toronto, Canada
11Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany
Abstract. Stratospheric transport in global circulation models and chemistry–climate models is an important component in simulating the recovery of the ozone layer as well as changes in the climate system. The Brewer–Dobson circulation is not well constrained by observations and further investigation is required to resolve uncertainties related to the mechanisms driving the circulation. This study has assessed the specified dynamics mode of the Canadian Middle Atmosphere Model (CMAM30) by comparing to the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) profile measurements of CFC-11 (CCl3F), CFC-12 (CCl2F2), and N2O. In the CMAM30 specified dynamics simulation, the meteorological fields are nudged using the ERA-Interim reanalysis and a specified tracer was employed for each species, with hemispherically defined surface measurements used as the boundary condition. A comprehensive sampling technique along the line of sight of the ACE-FTS measurements has been utilized to allow for direct comparisons between the simulated and measured tracer concentrations. The model consistently overpredicts tracer concentrations of CFC-11, CFC-12, and N2O in the lower stratosphere, particularly in the northern hemispheric winter and spring seasons. The three mixing barriers investigated, including the polar vortex, the extratropical tropopause, and the tropical pipe, show that there are significant inconsistencies between the measurements and the simulations. In particular, the CMAM30 simulation underpredicts mixing efficiency in the tropical lower stratosphere during the June–July–August season.
Citation: Kolonjari, F., Plummer, D. A., Walker, K. A., Boone, C. D., Elkins, J. W., Hegglin, M. I., Manney, G. L., Moore, F. L., Pendlebury, D., Ray, E. A., Rosenlof, K. H., and Stiller, G. P.: Assessing stratospheric transport in the CMAM30 simulations using ACE-FTS measurements, Atmos. Chem. Phys., 18, 6801-6828, https://doi.org/10.5194/acp-18-6801-2018, 2018.
Publications Copernicus
Download
Short summary
We used satellite observations and model simulations of CFC-11, CFC-12, and N2O to investigate stratospheric transport, which is important for predicting the recovery of the ozone layer and future climate. We found that sampling can impact results and that the model consistently overestimates concentrations of these gases in the lower stratosphere, consistent with a too rapid Brewer–Dobson circulation. An issue with mixing in the tropical lower stratosphere in June–July–August was also found.
We used satellite observations and model simulations of CFC-11, CFC-12, and N2O to investigate...
Share