Southern Ocean drives multidecadal atmospheric CO 2 rise during Heinrich Stadials

• Autores: Wendt, Kathleen A.; Nehrbass Ahles, Christoph; Niezgoda, Kyle; Noone, David; Kalk, Michael; Menviel, Laurie; Gottschalk, Julia; Rae, James W. B.; Schmitt, Jochen; Fischer, Hubertus; Stocker, Thomas F.; Muglia, Juan; Ferreira, David; Marcott, Shaun A.; Brook, Edward; Buizert, Christo
• Año de publicación: 2024
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: ICE CORE; PALEOCLIMATE; CARBON CYCLE; HEINRICH STADIALS; CARBON DIOXIDE
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

The last glacial period was punctuated by cold intervals in the North Atlantic region that culminated in extensive iceberg discharge events. These cold intervals, known as Heinrich Stadials, are associated with abrupt climate shifts worldwide. Here, we present CO2 measurements from the West Antarctic Ice Sheet Divide ice core across Heinrich Stadials 2 to 5 at decadal-scale resolution. Our results reveal multi-decadal-scale jumps in atmospheric CO2 concentrations within each Heinrich Stadial. The largest magnitude of change (14.0 ± 0.8 ppm within 55 ± 10 y) occurred during Heinrich Stadial 4. Abrupt rises in atmospheric CO2 are concurrent with jumps in atmospheric CH4 and abrupt changes in the water isotopologs in multiple Antarctic ice cores, the latter of which suggest rapid warming of both Antarctica and Southern Ocean vapor source regions. The synchroneity of these rapid shifts points to wind-driven upwelling of relatively warm, carbon-rich waters in the Southern Ocean, likely linked to a poleward intensification of the Southern Hemisphere westerly winds. Using an isotope-enabled atmospheric circulation model, we show that observed changes in Antarctic water isotopologs can be explained by abrupt and widespread Southern Ocean warming. Our work presents evidence for a multi-decadal- to century-scale response of the Southern Ocean to changes in atmospheric circulation, demonstrating the potential for dynamic changes in Southern Ocean biogeochemistry and circulation on human timescales. Furthermore, it suggests that anthropogenic CO2 uptake in the Southern Ocean may weaken with poleward strengthening westerlies today and into the future.
Fil: Wendt, Kathleen A.. State University Of Oregon. College Of Earth, Ocean And Atmospheric Sciences.; Estados Unidos
Fil: Nehrbass Ahles, Christoph. University of Bern; Suiza. National Physical Laboratory; Reino Unido
Fil: Niezgoda, Kyle. State University Of Oregon. College Of Earth, Ocean And Atmospheric Sciences.; Estados Unidos
Fil: Noone, David. State University Of Oregon. College Of Earth, Ocean And Atmospheric Sciences.; Estados Unidos
Fil: Kalk, Michael. State University Of Oregon. College Of Earth, Ocean And Atmospheric Sciences.; Estados Unidos
Fil: Menviel, Laurie. University of New South Wales; Australia
Fil: Gottschalk, Julia. Christian Albrechts Universitat Zu Kiel.; Alemania
Fil: Rae, James W. B.. University of St. Andrews; Reino Unido
Fil: Schmitt, Jochen. University of Bern; Suiza
Fil: Fischer, Hubertus. University of Bern; Suiza
Fil: Stocker, Thomas F.. University of Bern; Suiza
Fil: Muglia, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina
Fil: Ferreira, David. University Of Reading. Departament Of Meteorology; Reino Unido
Fil: Marcott, Shaun A.. University of Wisconsin; Estados Unidos
Fil: Brook, Edward. State University Of Oregon. College Of Earth, Ocean And Atmospheric Sciences.; Estados Unidos
Fil: Buizert, Christo. State University Of Oregon. College Of Earth, Ocean And Atmospheric Sciences.; Estados Unidos