Patterns of Ocean Heat Uptake and Time Varying Climate Sensitivity
Abstract
Predicting the transient climate response or equilibrium climate sensitivity will help to adapt, mitigate, or possibly preventclimate change. It is debated to which degree the horizontal and vertical pattern of thermal forcing influencesthe equilibration of global surface temperature following a perturbation. For example, the aerosol distributionor ocean heat uptake patterns can set the pace of both regional and global equilibration of a CO2 inducedwarming or cooling signal. Recent discussions suggest that high latitude ocean heat uptake or release is moreefficient in cooling or warming the global atmosphere than low latitude heat uptake or release. This implies that knowledge of the evolution of heat uptakepatterns is a necessary condition to predict global climate sensitivity.So far these effects have been mostly studied in equilibrium idealized aqua planet simulations withoutseasons or sea ice. We analyze fully coupled GCM and intermediate complexity model simulations withrealistic continents, sea ice distribution, and seasonality. We show how local ocean heat content equilibrateson time scales of decades to millennia and then force a slab ocean model with characteristic deep oceanheat uptake patterns for different time slices. The aim is to imitate several stages in the equilibrationprocess, presenting low versus high latitude northern or southern hemispheric ocean heat uptake. We discuss whichatmospheric feedbacks enhance or dampen the ocean heat uptake signal depending on the location. Wefinally show to which degree and where local heat uptake can impact global climate sensitivity.
- Publication:
-
American Geophysical Union, Ocean Sciences Meeting
- Pub Date:
- February 2016
- Bibcode:
- 2016AGUOSHE14B1414R
- Keywords:
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- 4207 Arctic and Antarctic oceanography;
- OCEANOGRAPHY: GENERALDE: 4504 Air/sea interactions;
- OCEANOGRAPHY: PHYSICALDE: 4540 Ice mechanics and air/sea/ice exchange processes;
- OCEANOGRAPHY: PHYSICALDE: 4572 Upper ocean and mixed layer processes;
- OCEANOGRAPHY: PHYSICAL