%0 Journal Article
%T What Controls Recent Changes in the Circulation of the Southern Hemisphere: Polar Stratospheric or Equatorial Surface Temperatures?
%A Isidoro Orlanski
%J Atmospheric and Climate Sciences
%P 497-509
%@ 2160-0422
%D 2013
%I Scientific Research Publishing
%R 10.4236/acs.2013.34052
%X <p class=\"MsoNormal\">
	<span lang=\"EN-US\"><span style=\"font-family:Verdana;\">Recent research suggests that both tropical ocean warming and
stratospheric temperature anomalies due to ozone depletion have led to a
poleward displacement of the midand high-latitude circulation of the Southern
Hemisphere over the past century. In this study, we attempt to distinguish the
influences of ocean warming and stratospheric cooling trends on seasonal
changes of both the zonally symmetric and asymmetric components of the southern
hemisphere circulation. Our analysis makes use of three data sets-the ERA40
reanalysis and results from two different runs of the GFDL global atmosphere
and land model (AM2.1) for the period 1870 to 2004. A regression analysis was
applied to two variables in each of the three data sets-the zonal component of
the surface wind U(</span><st1:chmetcnv unitname=\"m\" sourcevalue=\"10\" hasspace=\"True\" negative=\"False\" numbertype=\"1\" tcsc=\"0\" w:st=\"on\"><st1:chmetcnv tcsc=\"0\" numbertype=\"1\" negative=\"False\" hasspace=\"False\" sourcevalue=\"10\" unitname=\"m\" w:st=\"on\"><span style=\"font-family:Verdana;\">10 </span></st1:chmetcnv><span style=\"font-family:Verdana;\">m</span></st1:chmetcnv><span style=\"font-family:Verdana;\">)
and the height at 300</span></span><span lang=\"EN-US\"> </span><span lang=\"EN-US\" style=\"font-family:Verdana;\">hPa</span><span lang=\"EN-US\" style=\"font-family:Verdana;\">¡ª</span><span lang=\"EN-US\" style=\"font-family:Verdana;\">to determine their correlation with zonally
averaged polar stratospheric temperatures (T_polar</span><span lang=\"EN-US\" style=\"font-family:Verdana;\">¡ª</span><span lang=\"EN-US\" style=\"font-family:Verdana;\">at 150</span><span lang=\"EN-US\"> </span><span lang=\"EN-US\" style=\"font-family:Verdana;\">hPa, averaged
over a band from 70S</span><span lang=\"EN-US\" style=\"font-family:Verdana;\"> - </span><span lang=\"EN-US\" style=\"font-family:Verdana;\">80S) and low-level equatorial temperatures (T_equator</span><span lang=\"EN-US\" style=\"font-family:Verdana;\">¡ª</span><span lang=\"EN-US\" style=\"font-family:Verdana;\">at 850
hPa averaged over a band at 5S</span><span lang=\"EN-US\"> </span><span lang=\"EN-US\" style=\"font-family:Verdana;\">-</span><span lang=\"EN-US\"> </span><span lang=\"EN-US\"><span style=\"font-family:Verdana;\">5N). Our analysis shows that the zonally </span><i><span style=\"font-family:Verdana;\">symmetric</span></i><span style=\"font-family:Verdana;\"> surface winds have a
considerably enhanced intensity in high latitudes of the
%K Southern Hemisphere Changes
%K Ozone Depletion
%K Ocean Warming
%K Poleward Stormtrack
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=36806