Climate Change from Meteorological Observations and Underground Temperatures in Northern Italy

Abstract

The change in the air temperature recorded at the Genoa University observatory over 155 years followed the change in the wind direction. A warming occurred both from 1838 to 1869 and from 1890 to 1950. The latter warm period was followed by a cooling in the 1950s, when the lowest mean annual temperature occurred. Generally, a warm period corresponds to a growth in the southern components of the ground wind direction; the increase in the southerly circulation in the Mediterranean yields increased stability in dry weather. Temperature-depth data measured in a geothermal borehole reflect this climate change. A comparison between the measurements and a synthetic temperature profile, based on the air temperature history recorded at the observatory, indicates that the average temperature prior to the meteorological time series was about 0.6 K higher than the average of the decade 1973-1982.