Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/acp-2017-1076
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
05 Dec 2017
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Chemistry and Physics (ACP).
Spatial and Temporal Variability of Interhemispheric Transport Times
Xiaokang Wu1,2, Huang Yang1, Darryn W. Waugh1, Clara Orbe1,3, Simone Tilmes4, and Jean-Francois Lamarque4 1Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, Maryland, USA
2Department of Atmospheric Sciences, Texas A&M University, College Station, Texas, USA
3Goddard Earth Science Technology and Research, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
4National Center for Atmospheric Research, Boulder, Colorado, USA
Abstract. The seasonal and interannual variability of transport times from the northern mid-latitude surface into the southern hemisphere is examined using simulations of three idealized age tracers: A ideal age tracer that yields the mean transit time from northern mid-latitudes and two tracers with uniform 50-day and 5-day decay. For all tracers the largest seasonal and interannual variability occurs near the surface within the tropics, and is generally closely coupled to movement of the intertropical convergence zones (ITCZ). There are, however, notable differences in variability between different tracers. The largest seasonal and interannual variability in the mean age is generally confined to latitudes spanning the ITCZ, with very weak variability in the southern extratropics. In contrast, for tracers subject to spatially uniform exponential loss the peak variability tends to be south of the ITCZ, and there is a smaller contrast between tropical and extratropical variability. These differences in variability occur because the distribution of transit time from northern mid-latitudes is very broad and tracers with more rapid loss are more sensitive to changes in fast time scales than the mean age tracer. These simulations suggest that the seasonal/interannual variability in the southern extratropics of trace gases, with predominantly NH mid-latitude sources, may differ depending on the gases' chemical lifetimes.

Citation: Wu, X., Yang, H., Waugh, D. W., Orbe, C., Tilmes, S., and Lamarque, J.-F.: Spatial and Temporal Variability of Interhemispheric Transport Times, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2017-1076, in review, 2017.
Xiaokang Wu et al.
Xiaokang Wu et al.
Xiaokang Wu et al.

Viewed

Total article views: 217 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
168 48 1 217 1 2

Views and downloads (calculated since 05 Dec 2017)

Cumulative views and downloads (calculated since 05 Dec 2017)

Viewed (geographical distribution)

Total article views: 217 (including HTML, PDF, and XML)

Thereof 217 with geography defined and 0 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 11 Dec 2017
Publications Copernicus
Download
Short summary
The seasonal and interannual variability of transport times from northern mid-latitudes into the southern hemisphere is examined using simulations of age tracers. The largest variability occurs near the surface close to the tropical convergence zones, but the peak is further south and there is a smaller tropical-extratropical contrast for tracers with more rapid loss. Hence the variability of trace gases in the southern extratropics will vary with their chemical lifetime.
The seasonal and interannual variability of transport times from northern mid-latitudes into the...
Share