Accession Number : ADP007341

Title :   Polar Ice Cores: Climatic and Environmental Records,

Corporate Author : LABORATOIRE DE GLACIOLOGIE ET GEOPHYSIQUE DE L'ENVIRONNEMENT SAINT-MARTIN D'HE RES (FRANCE)

Personal Author(s) : Lorius, C.

Report Date : MAR 1992

Pagination or Media Count : 6

Abstract : Ice cores from Greenland and Antarctica provide multiple proxy records of climatic and environmental parameters. They reveal the anthropogenic impact on aerosol concentrations in Greenland snow (i.e., S04 and N03) and on atmospheric greenhouse gases. For example, increases over the last 200 years are about 25% for C02, 8 % for N202 and about 200% for CH4. Over the last climatic cycle (i.e., - 150 Kyr) the glacial-interglacial surface temperature change may be -1O deg C, with glacial stages generally associated with lower snow accumulation and higher concentrations of marine and continental aerosols reflecting enlarged source areas and increased atmospheric transport. Greenland ice has recorded rapid changes of climate during the last ice age and deglaciation. The 18 or D records from the Vostok ice core (Antarctica) strongly suggest the role of insolation orbital forcing, as well as a close relation between temperature and greenhouse gas concentrations. C02 and CH4 concentrations increase by about 40% and 100% during glacial interglacial transitions, respectively. It appears likely that fluctuating greenhouse gas concentrations have had a significant role in the glacial-interglacial climate changes by amplifying, together with the growth and decay of the Northern Hemisphere ice sheets, the orbital forcing.

Descriptors :   *AEROSOLS, *CLIMATE, *CORES, *GREENLAND, *ICE, *SHEETS, *SNOW, *POLAR REGIONS, *ANTARCTIC REGIONS, ACCUMULATION, ATMOSPHERICS, CYCLES, DECAY, GREENHOUSES, HEMISPHERES, IMPACT, NORTHERN HEMISPHERE, PARAMETERS, RECORDS, SURFACE TEMPERATURE, SURFACES, TEMPERATURE, TRANSITIONS, TRANSPORT, SYMPOSIA, GLACIERS, METHANE, CARBON DIOXIDE, NITROGEN.

Subject Categories : Geography
      Snow, Ice and Permafrost
      Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE