The Active Role of the Ocean in the Temporal Evolution of Climate Sensitivity

TitleThe Active Role of the Ocean in the Temporal Evolution of Climate Sensitivity
Publication TypeJournal Article
Year of Publication2018
JournalGeophysical Research Letters
Volume45
Number1
Pages306-315
Date Published04/2018
Abstract / Summary

The temporal evolution of the effective climate sensitivity is shown to be influenced by the changing pattern of sea surface temperature (SST) and ocean heat uptake (OHU), which in turn have been attributed to ocean circulation changes. A set of novel experiments are performed to isolate the active role of the ocean by comparing a fully coupled CO2 quadrupling community Earth System Model (CESM) simulation against a partially coupled one, where the effect of the ocean circulation change and its impact on surface fluxes are disabled. The active OHU is responsible for the reduced effective climate sensitivity and weaker surface warming response in the fully coupled simulation. The passive OHU excites qualitatively similar feedbacks to CO2 quadrupling in a slab ocean model configuration due to the similar SST spatial pattern response in both experiments. Additionally, the nonunitary forcing efficacy of the active OHU (1.7) explains the very different net feedback parameters in the fully and partially coupled responses.

URLhttp://dx.doi.org/10.1002/2017gl075633
DOI10.1002/2017gl075633
Journal: Geophysical Research Letters
Year of Publication: 2018
Volume: 45
Number: 1
Pages: 306-315
Date Published: 04/2018

The temporal evolution of the effective climate sensitivity is shown to be influenced by the changing pattern of sea surface temperature (SST) and ocean heat uptake (OHU), which in turn have been attributed to ocean circulation changes. A set of novel experiments are performed to isolate the active role of the ocean by comparing a fully coupled CO2 quadrupling community Earth System Model (CESM) simulation against a partially coupled one, where the effect of the ocean circulation change and its impact on surface fluxes are disabled. The active OHU is responsible for the reduced effective climate sensitivity and weaker surface warming response in the fully coupled simulation. The passive OHU excites qualitatively similar feedbacks to CO2 quadrupling in a slab ocean model configuration due to the similar SST spatial pattern response in both experiments. Additionally, the nonunitary forcing efficacy of the active OHU (1.7) explains the very different net feedback parameters in the fully and partially coupled responses.

DOI: 10.1002/2017gl075633
Citation:
Garuba, O, J Lu, F Liu, and H Singh.  2018.  "The Active Role of the Ocean in the Temporal Evolution of Climate Sensitivity."  Geophysical Research Letters 45(1): 306-315.  https://doi.org/10.1002/2017gl075633.