Abstract

Sea ice is a crucial parameter in the climate system, and it is declining at a faster rate than models predicted. Bromine plays a central role in sea ice chemistry, from where it is released as BrO during springtime, enriching its abundance in the polar atmosphere. Therefore, bromine enrichment in snow, with respect to the sodium ratio in seawater, can be been linked to first year sea ice variability at the Poles. Measurements of Bromine enrichment (Br_enr) have been carried out in Greenland (NEEM and Renland ice cores), Svalbard, Severnaya Zemlya and Antarctica (Talos Dome, Law Dome and Dome C). These climate ice archives investigated, cover both the satellite era and the older climate periods back to the last glaciation. In addition, to better understand the Br signal in the ice core, several surface experiments have been planned and conduct in several polar locations (Antarctic Plateau, Svalbard, Greenland) with the aim to understand the process controlling the Br deposition and its enrichment as well the possible post-depositional process that can occur at the snow surface.