Progetti Finanziati

Could dust contribute to cause the observed abrupt changes in the Arctic? ICED EARTH aims to put the bases to tackle this question through simulations with a global Earth System Model of high complexity (IPSLCM6). Dust-cryosphere processes are only just starting to be fully implemented in global ESMs, often in a fragmented way. In ICED EARTH, deposition of mineral dust and carbonaceous aerosols will be coherently coupled to snow albedo on land. Simulations will be tested against available observations.

L'ultima deglaciazione è una fase di riscaldamento che segue l'ultimo massimo glaciale (21k fa). I modelli suggeriscono che, durante questa transizione, la fusione del permafrost ha esercitato un feedback positivo sul cambiamento climatico rilasciando CO2/CH4 in atmosfera. Processi e tempi di rilascio del carbonio rimangono  tuttavia ancora poco chiari. PAST-HEAT esaminerà il comportamento del permafrost durante l'ultima deglaciazione per migliorare la nostra comprensione sul ciclo del carbonio post-glaciale e chiarire come i suoli artici risponderanno ai cambiamenti climatici in un futuro scenario di amplificazione polare. 

The Higher North Atlantic (HNA), Svalbard and Greenland east coastal regions are experiencing rapid climate change with sustained temperature increases and loss of sea ice. This disappearance of old ice is cited as one of the causes of the recent exceptional warming of the Arctic HNA[1], together with increasing inflow into the Fram Strait of the Atlantic meridional overturning circulation (AMOC)[2]. Changes in the extension and type of sea ice have a direct impact on heat transfer and on Arctic biological and biogeochemical cycles. Sea ice is a physical barrier to heat and water vapor exchange, also influencing water stable isotopes in precipitation. Sea ice is also involved in the oxidative capacity of the Arctic atmosphere, injecting in spring enormous amounts of Br radicals through bromine explosions that then directly affect the atmospheric cycle of mercury and contribute to ozone depletion at many Arctic sites. How recent sea ice loss has impacted these Arctic chemical processes is not properly understood. The aims of this project are to use: water stable isotopes as a fingerprint of air mass sources, climate model simulations and atmospheric re-analysis to evaluate the climate impact of sea ice disappearance on two Arctic basins, namely the Barents Sea and the Fram Strait regions, and to evaluate how bromine sea ice chemistry effects atmospheric mercury deposition rates and atmospheric ozone lifetimes in Svalbard and the east Greenland region.