Uncertainty in the evolution of climate feedback traced to the strength of the Atlantic Meridional Overturning Circulation
File(s)2019GL083084.pdf (8.24 MB)
Published version
Author(s)
Lin, Yuan‐Jen
Hwang, Yen‐Ting
Ceppi, Paulo
Gregory, Jonathan
Type
Journal Article
Abstract
In most coupled climate models, effective climate sensitivity increases for a few decades following an abrupt CO2 increase. The change in the climate feedback parameter between the first 20 years and the subsequent 130 years is highly model dependent. In this study, we suggest that the intermodel spread of changes in climate feedback can be partially traced to the evolution of the Atlantic Meridional Overturning Circulation. Models with stronger Atlantic Meridional Overturning Circulation recovery tend to project more amplified warming in the Northern Hemisphere a few decades after a quadrupling of CO2. Tropospheric stability then decreases as the Northern Hemisphere gets warmer, which leads to an increase in both the lapse‐rate and shortwave cloud feedbacks. Our results suggest that constraining future ocean circulation changes will be necessary for accurate climate sensitivity projections.
Date Issued
2019-11-16
Date Acceptance
2019-10-11
Citation
Geophysical Research Letters, 2019, 46 (21), pp.12331-12339
ISSN
0094-8276
Publisher
American Geophysical Union (AGU)
Start Page
12331
End Page
12339
Journal / Book Title
Geophysical Research Letters
Volume
46
Issue
21
Copyright Statement
©2019. American Geophysical Union. All Rights Reserved.
Subjects
Science & Technology
Physical Sciences
Geosciences, Multidisciplinary
Geology
climate sensitivity
climate feedback
Atlantic Meridional Overturning Circulation
SURFACE-TEMPERATURE-CHANGE
RADIATIVE FEEDBACKS
THERMOHALINE CIRCULATION
OCEAN CIRCULATION
EVOLVING PATTERNS
SPATIAL-PATTERN
ATMOSPHERIC CO2
NORTH-ATLANTIC
GLOBAL CLOUD
SEA-LEVEL
Meteorology & Atmospheric Sciences
Publication Status
Published
Article Number
2019GL083084
Date Publish Online
2019-10-22