Why Future Shifts in Tropical Precipitation Will Likely Be Small
- Author(s)
- Aaron Donohoe, Aiko Voigt
- Abstract
The region of tropical convective precipitation (the ITCZ) migrates by approximately 12° of latitude over the seasonal cycle with an annual mean position slightly north of the equator. We demonstrate that the ITCZ is located in the hemisphere in which the atmosphere is heated more strongly. A 3° latitude ITCZ shift requires approximately 1 PW of energy input into the atmosphere in one hemisphere with equal cooling in the other hemisphere. This relationship is shown to apply to the climatological seasonal cycle, the interannual variability and the response to both paleoclimatic and anthropogenic forcing. Future changes in the ITCZ position will likely conform the 3° latitude shift per PW of hemispherically asymmetric atmospheric heating. Since hemi-spherically asymmetric forcings and climate feedbacks are small (<< 1 PW), future changes in ITCZ position will likely be very small (<1° latitude). Indeed, ensembles of coupled climate models simulate ITCZ shifts that are not significantly different from zero in response to an instantaneous quadrupling of carbon dioxide.
- Organisation(s)
- Department of Meteorology and Geophysics
- External organisation(s)
- Lamont-Doherty Earth Observatory
- Volume
- 226
- Pages
- 115-137
- No. of pages
- 23
- DOI
- https://doi.org/10.1002/9781119068020.ch8
- Publication date
- 2017
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105204 Climatology, 105205 Climate change
- ASJC Scopus subject areas
- Geophysics
- Sustainable Development Goals
- SDG 13 - Climate Action
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/09da3533-84f1-4d6b-8c40-df163fdc0bd9