CafoscariNEWS

Antarctic: “The wind as a driving force of climate in sea ice formation and thickening”

Photography of Terra Nova Bay (Ross Sea, Antarctic), katabatic wind and neo-formation of sea ice (Frezzotti M. ENEA-PNRA)

Sea ice - or ice packs - is a fundamental element of the climate system and its seasonal cycle affects the global dynamics of climate for its interplay with the planetary albedo, atmospheric circulation, ocean productivity and it being a fundamental element of polar marine ecosystems.

Sea ice variability is driven by mechanisms caused by natural environmental and anthropogenic forces are still little understood.

The research published on the journal Nature Communications has explained the environmental process that have affected sea ice variability and abundances in penguins and seal in the Ross Sea region in Antarctica in the last 10 thousand years.

The study was carried out by Italian researchers as part of the National Research Program in Antarctica (Enea for logistic, Cnr for organization and scientific coordination) and TALDICE (www.taldice.org) and a PhD in collaboration with the universities of Trieste and Siena by Dr.  Karin Mezgec.

“Our research - explained Massimo Frezzotti researcher at ENEA - highlighted how winds blowing in Antarctica have an essential role, comparable to (or even more important than) temperatures and rains in affecting climate and conditioning polar ecosystems. Climate models should be able of reproducing the  persistence and strength of the wind in the past millennia to simulate climate changes in Antarctica induced by fossil fuel”.

“Changes in the extent of sea ice in the past can be reconstructed by climate indicators, or “proxy”, which can be recorded in marine and glacial archives, explained Barbara Stenni, paleoclimatologist and professor at Ca’ Foscari University of Venice. These can be found in ice cores and in water-sediment from the Ross Sea area”.

“The changes in the extent and persistence of sea ice has affected the evolution of coastal areas and accessibility to beaches, offering seals and Adélie penguins opportunities to colonize the many coasts of Ross Sea, modifying their diet as shown by the many abandoned colonies conserving the stratification of the several phases of occupation”, explained Carlo Baroni and Maria Cristina Salvatore, professors at the Department of Earth Science of the University of Pisa and associated researchers at the CNR-IGG in Pisa.

“For the first time a link has been established knowing atmospheric data, ice cores and sediment cores. Thanks to diatoms, silica algae dominating in the cold Antarctic Seas, the marine environment was revealed, from columnar ice to sediments. The presence-absence of characteristic species highlighted the great climate variability of this time window that is so closed to our contemporary world” said Ester Colizza, sedimentologist, and Romana Melis, micropaleontologist at the Department of MAthematics and Geosciences at the University of Trieste.