The temperature time series extends from 1952 to the end of 1994. Below 2000m, we find clear evidence for decadal variability as noted earlier by Clarke et al. [1990]. We observe two relatively warm periods, the first between 1955 and 1965, the second lasting from 1982 until the end of the time series. In contrast to these warm periods, the temperature of the deep water in the Greenland Sea was low during the early 1950s (-1.25C > theta > -1.3C) and in the 1970s (theta < -1.3C). During the 1980s and early 1990s, the temperatures increased steadily, exceeding -1.2C at the end of 1994. The indication of a similar warming trend during the early 1960s is strongly dependent on a single data point (ATKA cruise 1962, 3027m) and is discussed in detail later.
In the depth range between 200m and 2000m, the variations are more complex. Between 1985 and 1994, this layer warmed monotonically, as indicated by the deepening of the -1.0 isotherm from 200m in 1985 to 1700m in 1994. Similar warming trends occured between 1954 and 1959 and between 1973 and 1976. The latter warming events, however, were neither as pronounced nor as long-lived as the one presently observed. The presence of cold upper Arctic Intermediate Water (2C > theta > -1.8C; 34.7 < S < 34.9; Swift and Aagaard [1981]) is visible several times as a temperature minumum at about 200m in Fig. 2a.
As noted earlier, surface temperature trends can not be addressed in this study due to data limitations.
