@article{222d6477c47a459fb872019db6553500,
title = "Limited decrease of Southern Ocean sulfur productivity across the penultimate termination",
abstract = "Productivity in the Pleistocene glacial Southern Ocean was probably enhanced owing to iron fertilization by aeolian dust. Marine sediments indicate such an increase north of the modern Antarctic Polar Front but reduced biogenic activity south of it. However, quantitative estimates for the integrated net effect are difficult to obtain. Here we use the SO42− isotopic composition and other geochemical ice core records from the Atlantic sector of the Southern Ocean to reconstruct net changes in integrated biogenic sulfur productivity in the surface ocean over the penultimate glacial termination. We show that biogenic SO42− aerosol contributes 58% and 85% to the sulfate budget in Dronning Maud Land during glacial and interglacial times, respectively, and that biogenic sulfate is derived predominately from the seasonal sea ice zone. Using our quantitative reconstruction of biogenic aerosol production in the Southern Ocean source region, we show that the average biogenic sulfate production integrated over the Atlantic sector was 16% higher in the penultimate glacial 137,000–153,000 years ago compared with the later Last Interglacial 120,000–125,000 years ago. An intermittent decrease in productivity observed during early peak interglacial warming suggests that a reduction in the seasonal sea ice zone may disrupt Southern Ocean ecosystems.",
keywords = "Carbon cycle, Palaeoclimate",
author = "Hubertus Fischer and Andrea Burke and Rae, {James William Buchanan} and Sugden, {Patrick J.} and Tobias Erhardt and Birthe Twarloh and Maria H{\"o}rhold and Johannes Freitag and Bradley Markle and Mirko Severi and Margareta Hansson and Joel Savarino and Helena Pryer and Emily Doyle and Eric Wolff",
note = "Funding: H.F. gratefully acknowledges the financial support by the Swiss National Science Foundation (grant nos. 200020_172506 and 200020B_200328) and sabbatical support by the University of St Andrews in 2022. This work is a contribution to the European Project for Ice Coring in Antarctica (EPICA), a joint European Science Foundation/European Commission scientific programme, funded by the EU (EPICA-MIS) and by national contributions from Belgium, Denmark, France, Germany, Italy, the Netherlands, Norway, Sweden, Switzerland and the UK. The main logistic support was provided by Institut Polaire Fran{\c c}ais Paul-{\'E}mile Victor and Programma Nazionale di Ricerche in Antartide (at Dome C) and Alfred-Wegener-Institut, Helmholtz-Zentrum f{\"u}r Polar- und Meeresforschung (at Dronning Maud Land). This is EPICA publication no. 323.",
year = "2025",
month = jan,
day = "3",
doi = "10.1038/s41561-024-01619-7",
language = "English",
volume = "Online",
journal = "Nature Geoscience",
issn = "1752-0894",
publisher = "Nature publishing group",
}