Climate changes modulated the history of Arctic iodine during the Last Glacial Cycle

• Published in: Nature Communications
• Main Authors: Corella, Juan Pablo, Maffezzoli, Niccolo, Spolaor, Andrea, Vallelonga, Paul, Cuevas, Carlos A., Scoto, Federico, Müller, Juliane, Vinther, Bo, Kjær, Helle A., Cozzi, Giulio, Edwards, Ross, Barbante, Carlo, Saiz-Lopez, A.
• Other Authors: Danish Research Council, European Commission, National Science Foundation (US), Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (Germany)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2022
• Subjects: Arctic; Arctic Ocean; Greenland; Alfred Wegener Institute; Dansgaard-Oeschger events; Greenland ice cores; Sea ice
• Online Access: http://hdl.handle.net/10261/268163; https://doi.org/10.1038/s41467-021-27642-5; https://doi.org/10.13039/100000001; https://doi.org/10.13039/501100000780; https://doi.org/10.13039/501100003207; https://api.elsevier.com/content/abstract/scopus_id/85122875627

9 pags., 4 figs. Iodine has a significant impact on promoting the formation of new ultrafine aerosol particles and accelerating tropospheric ozone loss, thereby affecting radiative forcing and climate. Therefore, understanding the long-term natural evolution of iodine, and its coupling with climate variability, is key to adequately assess its effect on climate on centennial to millennial timescales. Here, using two Greenland ice cores (NEEM and RECAP), we report the Arctic iodine variability during the last 127,000 years. We find the highest and lowest iodine levels recorded during interglacial and glacial periods, respectively, modulated by ocean bioproductivity and sea ice dynamics. Our sub-decadal resolution measurements reveal that high frequency iodine emission variability occurred in pace with Dansgaard/Oeschger events, highlighting the rapid Arctic ocean-ice-atmosphere iodine exchange response to abrupt climate changes. Finally, we discuss if iodine levels during past warmer-than-present climate phases can serve as analogues of future scenarios under an expected ice-free Arctic Ocean. We argue that the combination of natural biogenic ocean iodine release (boosted by ongoing Arctic warming and sea ice retreat) and anthropogenic ozone-induced iodine emissions may lead to a near future scenario with the highest iodine levels of the last 127,000 years. This study received funding from the European Research Council (ERC) Executive Agency under the European Union´s Horizon 2020 Research and Innovation programme (Project ‘ERC-2016-COG 726349 CLIMAHAL’). The RECAP ice coring effort was financed by the Danish Research Council through a Sapere Aude grant, the NSF through the Division of Polar Programmes, the Alfred Wegener Institute, and the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement 610055 through the Ice2Ice project and the Early Human Impact project (267696). Peer reviewed