Atmos. Chem. Phys. Discuss., 7, 9367-9384, 2007
www.atmos-chem-phys-discuss.net/7/9367/2007/
doi:10.5194/acpd-7-9367-2007
© Author(s) 2007. This work is licensed under the
Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.
Review Status
This discussion paper has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP.
Observed poleward expansion of the Hadley circulation since 1979
Y. Hu1 and Q. Fu2
1Dept. of Atmospheric Sciences, Peking University, Beijing, China
2Dept. of Atmospheric Sciences, University of Washington, Seattle, USA

Abstract. Using three meteorological reanalyses and three outgoing long-wave radiation (OLR) datasets, we show that the Hadley circulation has a significant poleward expansion of about 2 to 4.5 degrees of latitude since 1979. The three reanalyses along with the MSU data all indicate that the poleward expansion of the Hadley circulation in each hemisphere occurs during its spring and fall seasons. Results from the OLR datasets do not have such seasonality. The expansion of the Hadley circulation implies a poleward expansion of the band of subtropical subsidence, leading to enhanced mid-latitude tropospheric warming and poleward shifts of the subtropical dry zone. This would contribute to an increased frequency of midlatitude droughts in both hemispheres.

Citation: Hu, Y. and Fu, Q.: Observed poleward expansion of the Hadley circulation since 1979, Atmos. Chem. Phys. Discuss., 7, 9367-9384, doi:10.5194/acpd-7-9367-2007, 2007.
 
Search ACPD
Discussion Paper
    XML
    Citation
    Final Revised Paper
    Share