The response of the hydrological cycle to climate variability and change is a critical open question, where model reliability is still unsatisfactory, yet upon which past climate history can shed some light. Sea ice is a key player in the climate system and in the hydrological cycle, due to its strong albedo effect and its insulating effect on local evaporation and air-sea heat flux. Using an atmospheric general circulation model with specified sea surface temperature and sea-ice distribution, the role of sea ice in the hydrological cycle is investigated under last glacial maximum (LGM) and present day conditions, and by studying its contribution to the "temperature-precipitation feedback". By conducting a set of sensitivity experiments in which the albedo and thickness of the sea ice are varied, the various effects of sea ice in the hydrological cycle are isolated. It is demonstrated that for a cold LGM like state, a warmer climate (as a result of reduced sea-ice cover) leads to an increase in snow precipitation over the ice sheets. The insulating effect of the sea ice on the hydrological cycle is found to be larger than the albedo effect. These two effects interact in a nonlinear way and their total effect is not equal to summing their separate contribution.
Bibliographical noteFunding Information:
This work was supported by the Israel-US Binational Science foundation. We thank Cecilia Bitz for providing the data for the LGM simulations. We thank Nili Harnik, Erick Fredj, Jeff Shaman, and Emmanuel Boss for helpful discussions and suggestions. ET is supported by NSF climate dynamics, P2C2 Grant ATM-0902844, and thanks to the Weizmann institute for its hospitality during parts of this work.
- Glacial-interglacial oscillations
- Hydrological cycle
- Sea ice
- Temperature-precipitation feedback