Sensitivity of Surface Temperature to Oceanic Forcing via q -Flux Green’s Function Experiments. Part II: Feedback Decomposition and Polar Amplification
- Physical Oceanography Laboratory, Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, and Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington
- Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec, Canada
A large set of Green’s function-type experiments is performed with q-flux forcings mimicking the effects of the ocean heat uptake (OHU) to examine the global surface air temperature (SAT) sensitivities to the location of the forcing. The result of the experiments confirms the earlier notion derived from experiments with different model complexities that the global mean SAT is far more sensitive to the oceanic forcing from high latitudes than the tropics. Remarkably, no matter in which latitude the q-flux forcings are placed, the SAT response is always characterized by a feature of polar amplification, implicating that it is intrinsic to our climate system. Considerable zonal asymmetry is also present in the efficacy of the tropical OHU, with the tropical eastern Pacific being much more efficient than the Indian Ocean and tropical Atlantic in driving global SAT warming by exciting the leading neutral mode of the SAT that projects strongly onto global mean warming. Using a radiative kernel, feedback analysis is also conducted to unravel the underlying processes responsible for the spatial heterogeneity in the global OHU efficacy, the polar amplification structures, and the tropical altruism of sharing the warmth with remote latitudes. Warming “altruism” for a q flux at a given latitude is also investigated in terms of the ratio of the induced remote latitudes versus the directly forced local warming. It is found that the tropics are much more altruistic than higher latitudes because of the high-energy transport efficiency of the Hadley circulation.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Grant/Contract Number:
- AC05-75RL01830; RGPIN 418305-13; 41676002; 41376009
- OSTI ID:
- 1461043
- Alternate ID(s):
- OSTI ID: 1544220
- Journal Information:
- Journal of Climate, Journal Name: Journal of Climate Vol. 31 Journal Issue: 17; ISSN 0894-8755
- Publisher:
- American Meteorological SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
A refined model for the Earth’s global energy balance
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journal | May 2019 |
Uncertainty in the Evolution of Climate Feedback Traced to the Strength of the Atlantic Meridional Overturning Circulation
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journal | November 2019 |
| Processed data of "The dominant contribution of Southern Ocean heat uptake to time-evolving radiative feedback in CESM" | dataset | January 2020 |
| Processed data of "The dominant contribution of Southern Ocean heat uptake to time-evolving radiative feedback in CESM" | dataset | January 2020 |
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