VOLCLIMA

The dimate of the last millennia and the ¡nfluence of external forcings (e.g. anthropogenic gas emissions) have received great attenlion over the past decades. Thus, the connection between volcanism, climate change and modes ofclimate variability has been a quite visited topic. Whereas the impact of volcaníc eruptions on global climate has been observecf and is widely accepted, there is still an open discussíon about the effect oí volcanic forcing on the individual climate modes, ¡.e. climate patterns with Ídentifjable patterns, specific regional effects, and often with oscillatory behaviour (e.g. El Nifío/a Southern Oscillation ENSO). We propase in VOLCLIMA that the volcanic signa! of large Southem HemJsphere (SH) volcanoes cannot pass unnoticed to the different climate system elements. We consider that, as it is largely demonstrated that happens ¡n the Northem Hemisphere, large eruptions occumng in the SH, including high-latitude ones, may significantly afféct the hemispheric climate in terms of heat and moisture balances, affecting Antarctic ice retreat/accumuiaiioh and atmospheric circulation patterns and modes such as the Antarctic Osciilation, the Soulhem Annular Mode (SAM) and indirectly, the current or forthcoming ENSO events. If our hypolhesis results correct, we could shed some líghí on the cause-effect link of volcanic eruptions and individual climatic modes. The methodological approach consists of obtaining three 7.5 m long marine sediment cores using the pistón core of the R/V Hesperides at Deception islands (Antarctica) interior bay, Port Foster. Deception Island ¡s a very active volcano with over 20 considerably large eruptions in the lastmillennia. The correiation ofthe evolution of volcanic eruptions and climate fluctuations will permit to assess the short” and long -íerm interactions behA/een both forcings and to determine their impact on the regional climate, as well as on the main climate modes (SAM, ENSO) and water currents.

Researchers