Summary
We present in situ observations of atmospheric and fast-ice parameters at Davis (68°35'S, 77°58'E), East Antarctica. Surface measurements from 1969–2003 reveal negative trends for summer and autumn surface-air temperatures, yet positive annual, winter and spring trends. Mean sea level pressure decreased over the observational record both annually (-0.10 hPa yr-1, significant at the 90% confidence level (90)) and seasonally. We mainly associate this with increased cyclonic activity. These trends reflect large-scale circulation changes identified by others in the troposphere and lower stratosphere. Temporal changes in the Davis landfast-ice characteristics are evaluated using in situ measurements from the late 1950s together with intermittent data from 1979 onward. There is large interannual variability in fast-ice characteristics, which peaked during the 1990s. Mean values of annual maximum ice thickness taken over subintervals have changed little. However, dates of annual maximum ice thickness and final fast-ice breakout are delayed (each by +0.43 d yr-1). Delays in ice breakout contribute to a prolonged persistence of the fast ice (+0.67 d yr-1, (90)). Linear regression was applied to relate changes in fast-ice characteristics to those in the atmosphere. Significant at the 90% level or above are: Winter temperature and annual maximum ice thickness are anticorrelated (R2 = -0.69); the tendency toward later dates of annual maximum ice thickness appears influenced by winter (R2 = +0.47) and spring (R2 = +0.42) warming. Interannual changes in spectral density of the (annual and summer, respectively) mean sea level pressure within the cyclone-active frequency band are crucial to annual maximum ice thickness (R2 = -0.54) and fast-ice breakout (R2 = -0.59). Maximum ice thickness is furthermore influenced by winter wind speed (R2 = -0.52).