The dependence of transient climate sensitivity and radiative feedbacks on the spatial pattern of ocean heat uptake
Abstract
The effect of ocean heat uptake (OHU) on transient global warming is studied in a multimodel framework. Simple heat sinks are prescribed in shallow aquaplanet ocean mixed layers underlying atmospheric general circulation models independently and combined with CO_2 forcing. Sinks are localized to either tropical or high latitudes, representing distinct modes of OHU found in coupled simulations. Tropical OHU produces modest cooling at all latitudes, offsetting only a fraction of CO_2 warming. High-latitude OHU produces three times more global mean cooling in a strongly polar-amplified pattern. Global sensitivities in each scenario are set primarily by large differences in local shortwave cloud feedbacks, robust across models. Differences in atmospheric energy transport set the pattern of temperature change. Results imply that global and regional warming rates depend sensitively on regional ocean processes setting the OHU pattern, and that equilibrium climate sensitivity cannot be reliably estimated from transient observations.
Additional Information
© 2014 American Geophysical Union. Received 4 December 2013; Accepted 13 January 2014; Accepted article online 24 January 2014; Published online 15 February 2014. We thank C. Bitz, G. Roe, D. Hartmann, A. Pendergrass, D. Frierson, and A. Donohoe for discussions and two anonymous reviewers for helpful comments. D.S.B. and B.E.J.R. were partially supported by NSF Division of Earth Sciences Continental Dynamics Programs, awards 0908558 and 1210920. K.C.A. was supported by a James S. McDonnell Foundation Postdoctoral Fellowship. D.D.B.K. was supported by NSF DMS-0940261, which is part of the Mathematics and Climate Research Network.Attached Files
Published - grl51371.pdf
Supplemental Material - Auxiliary_revised.docx
Supplemental Material - FigureA1.pdf
Supplemental Material - FigureA2.pdf
Files
Additional details
- Eprint ID
- 45464
- Resolver ID
- CaltechAUTHORS:20140502-093136261
- DMS-0940261
- NSF
- 0908558
- NSF Division of Earth Sciences Continental Dynamics Program
- 1210920
- NSF Division of Earth Sciences Continental Dynamics Program
- James S. McDonnell Foundation Postdoctoral Fellowship
- Created
-
2014-05-02Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field