In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 18, No. 10 ( 2018-05-25), p. 7217-7235
Abstract:
Abstract. Understanding and modeling the large-scale transport of trace gases and
aerosols is important for interpreting past (and projecting future) changes
in atmospheric composition. Here we show that there are large differences in
the global-scale atmospheric transport properties among the models
participating in the IGAC SPARC Chemistry–Climate Model Initiative (CCMI).
Specifically, we find up to 40 % differences in the transport timescales
connecting the Northern Hemisphere (NH) midlatitude surface to the Arctic and
to Southern Hemisphere high latitudes, where the mean age ranges between 1.7
and 2.6 years. We show that these differences are related to large
differences in vertical transport among the simulations, in particular to
differences in parameterized convection over the oceans. While stronger
convection over NH midlatitudes is associated with slower transport to the
Arctic, stronger convection in the tropics and subtropics is associated with
faster interhemispheric transport. We also show that the differences among
simulations constrained with fields derived from the same reanalysis products
are as large as (and in some cases larger than) the differences among
free-running simulations, most likely due to larger differences in
parameterized convection. Our results indicate that care must be taken when
using simulations constrained with analyzed winds to interpret the influence
of meteorology on tropospheric composition.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-18-7217-2018
DOI:
10.5194/acp-18-7217-2018-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1