Article 1: Warming of the Southern Ocean Since the 1950s Sarah T. Gille (15 February 2002) Science 295 (5558), 1275. [DOI: 10.1126/science.1065863]
Based on a number of temperature reading methods, including permanent floats that decrease in depth to measure temperature at a range of depths, and ship measurements, Gille found that, since 1950, there has been an average increase in temperature of about 0.1° C from 1955 to 1995 in the Southern Ocean. Most of this warming is in the upper km of the ocean. These readings were taken here, however, are a measure of primarily subsurface temperature readings due to the Antarctic Circulation Current's presence in the region, which brings mid-depth water to the surface. However, from 1930 to 1955, there was a negligible increase in temperate of the same region, suggesting that this rise has not been long-term. Also, the increase in temperature of the southern ocean is not uniform; the greatest increase in temperature was found to be at the more southern latitudes, but also is significant in discrete areas along the southern coast of Africa. This figure nicely illustrates the discovered temperature changes, in °C/year.
It is also of note that most temperature changes were found along a subset of ocean called "Subantarctic mode water," which annually ventilates and is therefore more sensitized to climate changes.
In summary, while small increases in temperature were found, they are significant in that they represent the more climate-resistant regions of the lower ocean.
Article 2:
CLIMATE CHANGE:Globe's 'Missing Warming' Found in the Ocean Richard A. Kerr (24 March 2000) Science 287 (5461), 2126. [DOI: 10.1126/science.287.5461.2126]
After recovering previously inaccessible records, it has been found that the oceans have warmed an average of .06°C between 1955 and 1995 in the region between surface and 3 km depth. According to Kerr, "heat content rose from a low point in the 1950s, peaked in the late '70s, dropped in the '80s, and rose to a higher peak in the '90s." This follows an earlier predicted model that describes the ocean's initial role as a buffer in global warming. Since dissolved CO2 levels decrease with increased ocean temperatures, the climate as a whole (and the oceans) will most likely experience an accelerated increase in temperature in the near future - on the "upper spectrum" of the range 1.5° - 4.5° total.