Publication Date:
2017-04-04
Description:
The effect of climate change on the Brewer–
Dobson circulation and, in particular, the large-scale
seasonal-mean transport between the troposphere and
stratosphere is compared in a number of middle
atmosphere general circulation models. All the models
reproduce the observed upwelling across the tropical
tropopause balanced by downwelling in the extra tropics,
though the seasonal cycle in upwelling in some
models is more semi-annual than annual. All the
models also consistently predict an increase in the mass
exchange rate in response to growing greenhouse gas
concentrations, irrespective of whether or not the
model includes interactive ozone chemistry. The mean
trend is 11 kt s–1 year–1 or about 2% per decade but
varies considerably between models. In all but one of
the models the increase in mass exchange occurs
throughout the year though, generally, the trend is
larger during the boreal winter. On average, more than
60% of the mean mass fluxes can be explained by the
EP-flux divergence using the downward control principle.
Trends in the annual mean mass fluxes derived
from the EP-flux divergence also explain about 60% of
the trend in the troposphere-to-stratosphere mass exchange
rate when averaged over all the models. Apart
from two models the interannual variability in the
downward control derived and actual mass fluxes were
generally well correlated, for the annual mean.
Description:
Published
Description:
727-741
Description:
JCR Journal
Description:
reserved
Keywords:
anthropogenic change
;
01. Atmosphere::01.01. Atmosphere::01.01.02. Climate
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
