The role of individual surface flux components in the passive and active ocean heat uptake
- BATTELLE (PACIFIC NW LAB)
- George Mason Universitiy
Ocean model experiments forced by different combinations of heat, freshwater, and momentum perturbations associated with CO$$_2$$ increase, are used to isolate the role of individual surface forcing components on the passive and active ocean heat uptake components. The forcings are derived from a fully coupled CO2-quadrupling experiment. The passive uptake is due to the passive absorption of surface heat flux anomalies directly caused by CO2 increase by ocean circulation, while the active or redistributive feedback uptake is the indirectly forced ocean heat uptake caused by ocean circulation change. The passive component is similar among the experiments, therefore, is not sensitive to the circulation anomaly variation among the experiments, but the active component shows large differences. Surface heat flux perturbation causes the passive heat uptake and most of the AMOC weakening, however, it results in a net active heat loss (14% of the passive uptake). This net active heat loss is the residual of the active heat gain, primarily in the North Atlantic and heat loss, largely in the tropical Pacific. Fresh-water perturbation weakens the AMOC a little more, but causes a large active heat gain (40% of the passive uptake), largely in the North Atlantic. Wind perturbation causes about the same amount of active heat loss as heat flux perturbation, due to the poleward shift of the subtropical cells in the Southern Hemisphere. The experiments show that active ocean heat uptake is not simply determined by the degree of AMOC weakening.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1773808
- Report Number(s):
- PNNL-SA-127642
- Journal Information:
- Journal of Climate, Vol. 31, Issue 15
- Country of Publication:
- United States
- Language:
- English