The Role of Thermohaline Circulation in Global Climate Change

The world ocean consists of 1.3 billion cu km of salty water, and covers 70.8% of the Earth's surface. This enormous body of water exerts a powerful influence on Earth's climate; indeed, it is an integral part of the global climate system. Therefore, understanding the climate system requires a knowledge of how the ocean and the atmosphere exchange heat, water and greenhouse gases. If we are to be able to gain a capability for predicting our changing climate we must learn, for example, how pools of warm salty water move about the ocean, what governs the growth and decay of sea ice, and how rapidly the deep ocean's interior responds to the changes in the atmosphere

Interocean Exchange

Earth’s climate, responding to the different thermodynamic properties of the land and ocean surfaces, is sensitive to the continental configuration and distribution of mountain ranges. This is clearly seen in the pattern of mean annual and seasonal range in such climate parameters as temperature and humidity and in the quasistationary patterns of atmospheric circulation, from small-scale sea breezes to planetary waves

Weddell Deep Water variability

Temperature of the Weddell Deep Water west of the Greenwich Meridian in 1977 is dramatically lower than that observed in the same region in 1973. The most intense thermal alteration extends from approximately 200 m to 2700 m. Cooling, which averages 0.2°C, accompanies a nearly density compensating salinity decrease, averaging 0.02‰...

Comment on the peripheral Antarctic-water discharge

No doubt the peripheral discharge around Antarctica tends to establish a westward coastal fl. ow and may slow the Antarctic Circumpolar Current significantly, as suggested by Barcilon (1966, 1967). It should be noted that this effect would have strong seasonal variations. Virtually all of the discharge is accomplished from midsummer to late summer...

Circumpolar View of the Southern Ocean from 1962 to 1992

The 1962-1992 period spanning the Eltanin/Islas Orcadas expeditions to the Ice Station Weddell, and the following World Ocean Circulation Experiment, may be viewed as the closing phase of an era of broad based, circumpolar surveys of the Southern Ocean. Today, investigating the spatial and temporal dimensions of such complex ocean and it’s coupling to the climate system, requires the integration of observations from ships, aircrafts, satellites, tethered instrumentation and autonomous vehicles with numerical models. However, the adventure of Southern Ocean observations remains the same, requiring not just the right people and technology, but also special ships capable of working within the harsh Antarctic environment, where unknowns await discovery

Antarctic Ocean polynyas

The spatial and temporal variability of sea ice concentrations derived from Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) brightness temperatures are presented. Emphasis is on the continental shelf region of the Ross Sea during 1984, when supporting data were obtained from oceanographic stations and moored instruments. The effects of the large spring polynya in the Ross Sea on summer insolation, surface heat layer storage, and late autumn ice formation are described

Temperature-Salinity Data from mooring M3, northwest Weddell Sea, 1999-2019

This project maintains an array of oceanographic moorings south of the South Orkney Islands in the Northwest Weddell Sea to provide a time series of the properties of the combined outflow of Antarctic Deep and Bottom Water drawn from various sites within the Weddell Sea. The goal of this project is to observe the properties of the Weddell deep and bottom waters as they exit the Weddell system. The data obtained over the course of a decade and more can be used to better understand deep water formation and long term changes in ocean circulation and their relation to the climate system

The eastern boundary of the Gulf Stream recirculation

A meridionally aligned thermocline front near 60W in the subtropical North Atlantic is revealed by the 1992 Trident data set. The front separates saltier thermocline water to the east from less salty water to the west. The eastern water is subjected to excess evaporation of the subtropics, while the western water is fed by lower salinity Gulf Stream water, which derives water from the wet tropical Atlantic. It is suggested that the front marks the eastern edge of the Gulf Stream recirculation cell, hence refer to it as the recirculation front. The surface layer displays a fan-like T/S scatter above the 18°C Subtropical Mode Water, with the fresher surface water located west of the recirculation front, and a subsurface salinity maximum to the east. In the lower thermocline (8 to 12°C) there is a step-like salinity increase of about 0.04 toward the east as measured along isotherms, producing two modes in the T/S scatter. At the intermediate water level (approximately in the 4 to 8°C range) the extent of the low salinity Antarctic Intermediate Water and salty Mediterranean outflow water are also reflected in the position of the recirculation front. That the front marks the easternmost extent of the Gulf Stream recirculation is supported by the potential vorticity, which reveals a region of high homogeneous values within the recirculation cell. East of the front, the potential vorticity field is sloped along isopycnals indicating the meridional flow of the Sverdrup interior. Mapping of the recirculation front using archived data reveals that it extends deep into the subtropical convergence zone (STCZ), a region whose fronts have all been previously attributed to Ekman convergence

Data from the INSTANT Makassar Strait moorings, 2004-2006: current meter, temperature, and salinity sensor records

This archive contains time series data records from two moorings in Makassar Strait, Indonesia, deployed during the International Nusantara Stratification and Transport program (INSTANT), 2004-2006. Raw and processed data from current meter, temperature and salinity sensors on the moorings are available. Raw and processed, gridded data from acoustic doppler current profilers (ADCP) on the two moorings are also available. A complete description of the project and archive contents can be found in the accompanying document file (Data_INSTANT-Makassar_Description.pdf)

Intraseasonal Kelvin Wave in Makassar Strait

Time series observations during 2004-2006 reveal the presence of 60-90 days intraseasonal events that impact the transport and mixing environment within Makassar Strait. The observed velocity and temperature fluctuations within the pycnocline reveal the presence of Kelvin waves including vertical energy propagation, energy equipartition, and nondispersive relationship. Two current meters at 750 and 1500 m provide further evidence that the vertical structure of the downwelling Kelvin wave resembles that of the second baroclinic wave mode. The Kelvin waves derive their energy from the equatorial Indian Ocean winds, including those associated with the Madden-Julian oscillations, and propagate from Lombok Strait to Makassar Strait along the 100-m isobath. The northward propagating Kelvin waves within the pycnocline reduce the southward Makassar Strait throughflow by up to 2 Sv and induce a marked increase of vertical diffusivity