Why Future Shifts in Tropical Precipitation Will Likely Be Small

Autor(en)
Aaron Donohoe, Aiko Voigt
Abstrakt

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(en)
Institut für Meteorologie und Geophysik
Externe Organisation(en)
Lamont-Doherty Earth Observatory
Band
226
Seiten
115-137
Anzahl der Seiten
23
DOI
https://doi.org/10.1002/9781119068020.ch8
Publikationsdatum
2017
Peer-reviewed
Ja
ÖFOS 2012
105204 Klimatologie, 105205 Klimawandel
ASJC Scopus Sachgebiete
Geophysics
Sustainable Development Goals
SDG 13 – Maßnahmen zum Klimaschutz
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/09da3533-84f1-4d6b-8c40-df163fdc0bd9