Last updated October 10, 2018

Multimodel attribution of the Southern Hemisphere Hadley cell widening: Major role of ozone depletion

  • States that it has been suggested the Hadley cell has been widening during the past three decades in both hemispheres, but attribution of its cause(s) remains challenging
  • Applies an optimal fingerprinting technique to 7 modern reanalyses and 49 coupled climate models participating in the CMIP3 and CMIP
  • Detects an influence of human‐induced stratospheric ozone depletion on the observed expansion of the Hadley cell in the Southern Hemisphere (SH) summer
  • Finds that the detected signal is separable from other external forcings that include greenhouse gases (GHGs), confirming a dominant role of stratospheric ozone in the SH summer climate change
  • The results are largely insensitive to observational and model uncertainties, providing additional evidence for a human contribution to the atmospheric circulation changes