Observations of the Meridional Overturning Circulation

Our current understanding of Atlantic meridional overturning is the product of decades of observations and increased modeling capability. It has been demonstrated that Atlantic MOC processes can effect climate change, particularly in response to large climate forcing, such as occurred at the glacial-interglacial transitions or might occur in response to anthropogenic forcing. As indicated above, much better projection capability will require many more years of in situ process studies and...

Ocean HeAt Upt Ake And Ocean Circulation FEEdbacks

The rate of global warming and the spatial distribution of warming are influenced by the uptake of heat by the oceans. Sea surface temperature (SST) is set by the ocean's heat uptake from the atmosphere upper ocean stratification, which depends on temperature, salinity, and winds and ocean currents, which are driven by the atmosphere. The SST is in turn a surface boundary condition for the atmosphere, impacting large-scale atmospheric wind patterns, most directly in the tropics, and impacting...

Hydrological Cycle Meridional Overturning Circulation Feedback

Freshwater export from the Arctic to the North Atlantic Ocean is governed by the total precipitation and runoff into the Arctic. Coupled modeling studies (Cubasch et al., 2001) suggest that a warmer world is one in which the hydrological cycle, and hence runoff into and precipitation over the Arctic, will be enhanced. Freshwater export from the Arctic can either be in the form of sea ice or liquid water and can exit the Arctic into the Atlantic through either Fram Strait or the Canadian...

Thermohaline Circulation Wind Feedback

The strength of the wind-driven circulation affects the MOC. In the northern North Atlantic the wind-driven circulation is part of the advection of water northward into the water mass formation areas. Intensification of the low pressure atmospheric system can have several effects (1) increasing the strength of the subpolar circulation and hence increasing the inflow of lower-latitude waters into convection regions and outflow of lower salinity arctic and subarctic waters to the south, and (2)...