Principle Investigators:
Prof. Arnold Gordon
Prof. Peter Schlosser

Changes of global climate in the past seem to have always involved the large-scale ocean circulation either as an active element, amplifier, or global communicator of climate change. The oceans transport large amounts of heat from the tropics to higher latitudes and between basins. Some of this heat transport is due to the horizontal wind driven circulation. However, most of the oceanic heat transport is due to the density-driven, thermohaline circulation.

Modern climate/ocean observations are needed to describe the present state and serve as initial conditions for model based prediction of the future evolution of the system. Presently a number of international planning efforts are underway within the GCOS/GOOS and CLIVAR framework to design a cost-effective, integrative global ocean observing system.

At Lamont we concentrate on several key locations:

In the South, around the Antarctic continent, observations are more sparse than in the north and time series hardly exist. In addition to logistical issues sea ice and the existence of several geographically widely separated deep-water formation regions poses a real challenge to any observational program. However, the Weddell gyre offers a unique setting for monitoring one of the major, if not the single most important, sources of Southern Ocean deep water in that it has a well developed gyre circulation. The western part of the gyre collects newly formed deep and bottom waters and advects them via a western boundary current northward along the Antarctic Peninsula towards the South Orkney plateau. Since 1999 we maintain a deep ocean time series station to observe the Weddell Sea outflow, see the CORC-ARCHES Southern Ocean. This project is part of the Climate Observations System of the Office of Climate Observation .

In the North, long-term observations in the center of the Labrador and Greenland Seas were started during the era of weather ships (1950-1975) and are now obtained by an internationally coordinated program with participation from several European countries, Canada and the US (ASOF and CLIVAR programs). In particular, efforts to measure the flow through Denmark Strait are the observational cornerstones to document the current state of dense water formation and density driven ocean overturning within the Atlantic sector. These efforts have been supported by CORC-ARCHES from its very beginning through partial funding of Dickson's current meter arrays.

Research Highlights:

• Implemented an ocean time series station in the North Western Weddell Sea to document climate variability and change in one of the sources for Southern Ocean Bottom water.
• Documented an steady increase in subsurface temperatures in the Weddell Sea over the last 20 years.