Ocean Currents Generate Large Footprints in Marine Palaeoclimate Proxies

TitleOcean Currents Generate Large Footprints in Marine Palaeoclimate Proxies
Publication TypeJournal Article
Year of Publication2015
JournalNature Communications
Volume6
Number6521
Date Published03/2015
Abstract / Summary

Fossils of marine microorganisms such as planktic foraminifera are among the cornerstones of palaeoclimatological studies. It is often assumed that the proxies derived from their shells represent ocean conditions above the location where they were deposited. Planktic foraminifera, however, are carried by ocean currents and, depending on the life traits of the species, potentially incorporate distant ocean conditions. Here we use high-resolution ocean models to assess the footprint of planktic foraminifera and validate our method with proxy analyses from two locations. Results show that foraminifera, and thus recorded palaeoclimatic conditions, may originate from areas up to several thousands of kilometres away, reflecting an ocean state significantly different from the core site. In the eastern equatorial regions and the western boundary current extensions, the offset may reach 1.5C for species living for a month and 3.0C for longer-living species. Oceanic transport hence appears to be a crucial aspect in the interpretation of proxy signals.

DOI10.1038/ncomms7521
Journal: Nature Communications
Year of Publication: 2015
Volume: 6
Number: 6521
Date Published: 03/2015

Fossils of marine microorganisms such as planktic foraminifera are among the cornerstones of palaeoclimatological studies. It is often assumed that the proxies derived from their shells represent ocean conditions above the location where they were deposited. Planktic foraminifera, however, are carried by ocean currents and, depending on the life traits of the species, potentially incorporate distant ocean conditions. Here we use high-resolution ocean models to assess the footprint of planktic foraminifera and validate our method with proxy analyses from two locations. Results show that foraminifera, and thus recorded palaeoclimatic conditions, may originate from areas up to several thousands of kilometres away, reflecting an ocean state significantly different from the core site. In the eastern equatorial regions and the western boundary current extensions, the offset may reach 1.5C for species living for a month and 3.0C for longer-living species. Oceanic transport hence appears to be a crucial aspect in the interpretation of proxy signals.

DOI: 10.1038/ncomms7521
Citation:
van Sebille, E, P Scussolini, JV Durgadoo, FJ Peeters, A Biastoch, W Weijer, C Turney, CB Paris, and R Zahn.  2015.  "Ocean Currents Generate Large Footprints in Marine Palaeoclimate Proxies."  Nature Communications 6(6521).  https://doi.org/10.1038/ncomms7521.