April 3rd, 2007 - h. 15:00

Auditorium B. Touschek  

Valter Maggi

(U. Bicocca - Milano)


Pleistocene records from polar ice cores: the atmospheric perspective


Continental records represent the direct impact of the climatic variability on the Earth system, but generally with regional variability.

Ice cores drilled in Antarctica and Greenland Ice Sheets permit to provide direct climatic informations of atmoshere. Recently the recovery of a deep ice core from Dome C, Antarctica, provides a climatic record fot the past 740.000 years.

For the four most recent glacial cycles, the data well agree with Vostok ice core, with four complete glacial/interglacial cycles, and most of the time in cold conditions. The early period, between 740.000 and 430.000 years ago, was characterized by less pronounced warmth in the interglacial periods, but a higher proportion of each cycle was spent in warm mode.

Another ice core drilled at Talos Dome, in a peripheria dome, close to the Pacific Ocean, provides informations on the relationship between the atmosphere and the continental ice. Besides, over the sable isotopes (oxygen and hydrogen), atmospheric chemistry and dust content, the ice core provides informations on the gas concentration of the main greenhouse gases (CO2, CH4, N2O).

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RB, 01/03/07