View in EDS

High Resolution Arctic Iodine Variability Since the Last Glacial Termination.

Saved in:
Bibliographic Details
Title: High Resolution Arctic Iodine Variability Since the Last Glacial Termination.
Authors: Segato, Delia1,2,3 (AUTHOR), Spolaor, Andrea1,2 (AUTHOR), Corella, Juan Pablo4 (AUTHOR), Cuevas, Carlos A.5 (AUTHOR), Burgay, François1,6 (AUTHOR), Fernandez, Rafael P.7 (AUTHOR), Turetta, Clara1,2 (AUTHOR), Cairns, Warren1,2 (AUTHOR), Kjær, Helle Astrid8 (AUTHOR), Spagnesi, Azzurra1 (AUTHOR), Lee, Khanghyun9 (AUTHOR), Erhardt, Tobias10,11 (AUTHOR), Jensen, Camilla M.11 (AUTHOR), Zeppenfeld, Chantal11 (AUTHOR), Barbante, Carlo1,2 (AUTHOR), Saiz‐Lopez, Alfonso5 (AUTHOR) a.saiz@csic.es
Source: Journal of Geophysical Research. Atmospheres. 12/28/2025, Vol. 130 Issue 24, p1-13. 13p.
Subject Terms: *Iodine, *Glaciation, *Ozone layer depletion, *Climate change, *Atmospheric chemistry, Arctic climate, Holocene Epoch, Ice cores
Geographic Terms: Arctic regions, North Atlantic Ocean, Greenland
Abstract: Tropospheric iodine plays a key role in ozone depletion and new particle formation. Understanding how iodine responds to climatic shifts is crucial for predicting future atmospheric composition. Here, we present high‐resolution iodine fluxes in the EGRIP (East GReenland Ice Core Project) ice core in central Greenland spanning the last 15.7 kyr. By integrating these data with complementary proxies from other ice and marine sediment cores, we explore both the temporal and spatial patterns of iodine deposition across the Greenland ice sheet. We find lower iodine fluxes at EGRIP compared to RECAP and NEEM ice cores over the last 15.7 kyr, explained by the lower efficiency of iodine transport to the interior of the ice sheet. Our results show that during the cold periods of the Last Glacial Termination (15.7–11.7 kyr before present), iodine fluxes at EGRIP were higher than during the Holocene, likely due to enhanced long‐range transport of iodine adsorbed onto dust and sea‐salt aerosols under stronger glacial wind regimes. In contrast, during the Holocene, the sources and transport pathways of iodine shifted to marine sources. We infer that iodine was increasingly emitted from the expanded seasonal sea ice area and biologically active subpolar North Atlantic waters, though overall fluxes at EGRIP were lower than during the glacial period, reflecting the reduction in long‐range transport. After rising until 5 kyr before present, iodine fluxes declined throughout the Neoglacial, in concomitance with regional cooling, increased sea ice extent, and reduced ocean productivity. Plain Language Summary: Atmospheric iodine contributes to ozone depletion and new particle formation, influencing the Earth's radiative balance. To investigate how iodine in the Arctic has changed over time, we present a high‐resolution record from the EGRIP ice core in central Greenland, spanning the last 15,700 yrs. In the oldest part of the record, the end of the last glacial period, iodine levels were relatively high, likely driven by strong winds transporting iodine bound to dust and sea salt aerosols over long distances. As the climate warmed during the Holocene, iodine sources shifted from dust to the ocean. Emissions were driven by seasonal sea ice and a more biologically productive open ocean, although overall levels declined due to reduced long‐range transport. As the climate continued to warm, iodine levels rose until around 5,000 yrs ago. A gradual decline of iodine was observed during the Neoglacial period, as sea ice expanded and ocean productivity decreased. These findings provide new insights into how Arctic iodine responds to climate shifts, which is key to understanding its future role in atmospheric chemistry and climate. Key Points: Atmospheric sources depositing iodine at EGRIP dominate post‐depositional processes over the last 15.7 kyrLong‐range transport dominated iodine deposition during the Last Glacial Termination, whereas marine emissions prevailed throughout the Holocene [ABSTRACT FROM AUTHOR]
Copyright of Journal of Geophysical Research. Atmospheres is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: GreenFILE
Description
Abstract:Tropospheric iodine plays a key role in ozone depletion and new particle formation. Understanding how iodine responds to climatic shifts is crucial for predicting future atmospheric composition. Here, we present high‐resolution iodine fluxes in the EGRIP (East GReenland Ice Core Project) ice core in central Greenland spanning the last 15.7 kyr. By integrating these data with complementary proxies from other ice and marine sediment cores, we explore both the temporal and spatial patterns of iodine deposition across the Greenland ice sheet. We find lower iodine fluxes at EGRIP compared to RECAP and NEEM ice cores over the last 15.7 kyr, explained by the lower efficiency of iodine transport to the interior of the ice sheet. Our results show that during the cold periods of the Last Glacial Termination (15.7–11.7 kyr before present), iodine fluxes at EGRIP were higher than during the Holocene, likely due to enhanced long‐range transport of iodine adsorbed onto dust and sea‐salt aerosols under stronger glacial wind regimes. In contrast, during the Holocene, the sources and transport pathways of iodine shifted to marine sources. We infer that iodine was increasingly emitted from the expanded seasonal sea ice area and biologically active subpolar North Atlantic waters, though overall fluxes at EGRIP were lower than during the glacial period, reflecting the reduction in long‐range transport. After rising until 5 kyr before present, iodine fluxes declined throughout the Neoglacial, in concomitance with regional cooling, increased sea ice extent, and reduced ocean productivity. Plain Language Summary: Atmospheric iodine contributes to ozone depletion and new particle formation, influencing the Earth's radiative balance. To investigate how iodine in the Arctic has changed over time, we present a high‐resolution record from the EGRIP ice core in central Greenland, spanning the last 15,700 yrs. In the oldest part of the record, the end of the last glacial period, iodine levels were relatively high, likely driven by strong winds transporting iodine bound to dust and sea salt aerosols over long distances. As the climate warmed during the Holocene, iodine sources shifted from dust to the ocean. Emissions were driven by seasonal sea ice and a more biologically productive open ocean, although overall levels declined due to reduced long‐range transport. As the climate continued to warm, iodine levels rose until around 5,000 yrs ago. A gradual decline of iodine was observed during the Neoglacial period, as sea ice expanded and ocean productivity decreased. These findings provide new insights into how Arctic iodine responds to climate shifts, which is key to understanding its future role in atmospheric chemistry and climate. Key Points: Atmospheric sources depositing iodine at EGRIP dominate post‐depositional processes over the last 15.7 kyrLong‐range transport dominated iodine deposition during the Last Glacial Termination, whereas marine emissions prevailed throughout the Holocene [ABSTRACT FROM AUTHOR]
ISSN:2169897X
DOI:10.1029/2025JD044552