Strengthening Atlantic inflow across the mid-pleistocene transition
The development of larger and longer lasting northern hemisphere ice sheets during the mid‐Pleistocene Transition (MPT) coincided with global cooling. Here, we show that surface waters of the north‐eastern Atlantic actually warmed across this interval (∼1.2–0.8 Ma), which we argue reflects an increa...
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American Geophysical Union
2021
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ftunivcardiff:oai:https://orca.cardiff.ac.uk:140272 2023-06-11T04:12:51+02:00 Strengthening Atlantic inflow across the mid-pleistocene transition Barker, Stephen Zhang, Xu Jonkers, Lukas Lordsmith, Sian Conn, Stephen Knorr, Gregor 2021-04-30 application/pdf https://orca.cardiff.ac.uk/id/eprint/140272/ https://doi.org/10.1029/2020PA004200 https://orca.cardiff.ac.uk/id/eprint/140272/3/2020PA004200.pdf en eng American Geophysical Union https://orca.cardiff.ac.uk/id/eprint/140272/3/2020PA004200.pdf Barker, Stephen https://orca.cardiff.ac.uk/view/cardiffauthors/A015364W.html orcid:0000-0001-7870-6431 orcid:0000-0001-7870-6431, Zhang, Xu, Jonkers, Lukas, Lordsmith, Sian, Conn, Stephen and Knorr, Gregor 2021. Strengthening Atlantic inflow across the mid-pleistocene transition. Paleoceanography and Paleoclimatology 36 (4) , e2020PA004200. 10.1029/2020PA004200 https://doi.org/10.1029/2020PA004200 file https://orca.cardiff.ac.uk/id/eprint/140272/3/2020PA004200.pdf doi:10.1029/2020PA004200 cc_by Article PeerReviewed 2021 ftunivcardiff https://doi.org/10.1029/2020PA004200 2023-05-04T22:37:03Z The development of larger and longer lasting northern hemisphere ice sheets during the mid‐Pleistocene Transition (MPT) coincided with global cooling. Here, we show that surface waters of the north‐eastern Atlantic actually warmed across this interval (∼1.2–0.8 Ma), which we argue reflects an increase in the north‐eastward transport of heat and moisture via the North Atlantic Current (NAC) into the Nordic Seas (the Atlantic Inflow). We suggest that simultaneous cooling and warming along the north‐western and south‐eastern margins (respectively) of the NAC during Marine Isotope Stage 28 (∼995 ka) reflected the increasing persistence of northern ice sheets as Atlantic Inflow increased. This resulted in a diachronous shift from ∼40 to ∼100 kyr cyclicity across the North East (NE) Atlantic as the growing influence of northern ice sheets spread southwards; to the north‐west of the NAC the first “100 kyr” cycle preceded Termination 12 (∼960 ka), while on the south‐eastern margin of the NAC the transition occurred ∼100 kyr later. Exploratory climate model simulations suggest that increasing Atlantic Inflow at this time could have accelerated ice sheet growth because pre‐existing moderately sized ice sheets allowed the positive effect of increasing precipitation to outpace melting. In addition, we propose that the dependence of post‐MPT ice sheets on moisture transport via the Atlantic Inflow may ultimately contribute to their apparent vulnerability to insolation forcing once a critical size threshold is crossed and high latitude ice sheets become starved of a vital moisture source. Article in Journal/Newspaper Ice Sheet Nordic Seas north atlantic current North Atlantic Cardiff University: ORCA (Online Research @ Cardiff) Paleoceanography and Paleoclimatology 36 4 |
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Open Polar |
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Cardiff University: ORCA (Online Research @ Cardiff) |
op_collection_id |
ftunivcardiff |
language |
English |
description |
The development of larger and longer lasting northern hemisphere ice sheets during the mid‐Pleistocene Transition (MPT) coincided with global cooling. Here, we show that surface waters of the north‐eastern Atlantic actually warmed across this interval (∼1.2–0.8 Ma), which we argue reflects an increase in the north‐eastward transport of heat and moisture via the North Atlantic Current (NAC) into the Nordic Seas (the Atlantic Inflow). We suggest that simultaneous cooling and warming along the north‐western and south‐eastern margins (respectively) of the NAC during Marine Isotope Stage 28 (∼995 ka) reflected the increasing persistence of northern ice sheets as Atlantic Inflow increased. This resulted in a diachronous shift from ∼40 to ∼100 kyr cyclicity across the North East (NE) Atlantic as the growing influence of northern ice sheets spread southwards; to the north‐west of the NAC the first “100 kyr” cycle preceded Termination 12 (∼960 ka), while on the south‐eastern margin of the NAC the transition occurred ∼100 kyr later. Exploratory climate model simulations suggest that increasing Atlantic Inflow at this time could have accelerated ice sheet growth because pre‐existing moderately sized ice sheets allowed the positive effect of increasing precipitation to outpace melting. In addition, we propose that the dependence of post‐MPT ice sheets on moisture transport via the Atlantic Inflow may ultimately contribute to their apparent vulnerability to insolation forcing once a critical size threshold is crossed and high latitude ice sheets become starved of a vital moisture source. |
format |
Article in Journal/Newspaper |
author |
Barker, Stephen Zhang, Xu Jonkers, Lukas Lordsmith, Sian Conn, Stephen Knorr, Gregor |
spellingShingle |
Barker, Stephen Zhang, Xu Jonkers, Lukas Lordsmith, Sian Conn, Stephen Knorr, Gregor Strengthening Atlantic inflow across the mid-pleistocene transition |
author_facet |
Barker, Stephen Zhang, Xu Jonkers, Lukas Lordsmith, Sian Conn, Stephen Knorr, Gregor |
author_sort |
Barker, Stephen |
title |
Strengthening Atlantic inflow across the mid-pleistocene transition |
title_short |
Strengthening Atlantic inflow across the mid-pleistocene transition |
title_full |
Strengthening Atlantic inflow across the mid-pleistocene transition |
title_fullStr |
Strengthening Atlantic inflow across the mid-pleistocene transition |
title_full_unstemmed |
Strengthening Atlantic inflow across the mid-pleistocene transition |
title_sort |
strengthening atlantic inflow across the mid-pleistocene transition |
publisher |
American Geophysical Union |
publishDate |
2021 |
url |
https://orca.cardiff.ac.uk/id/eprint/140272/ https://doi.org/10.1029/2020PA004200 https://orca.cardiff.ac.uk/id/eprint/140272/3/2020PA004200.pdf |
genre |
Ice Sheet Nordic Seas north atlantic current North Atlantic |
genre_facet |
Ice Sheet Nordic Seas north atlantic current North Atlantic |
op_relation |
https://orca.cardiff.ac.uk/id/eprint/140272/3/2020PA004200.pdf Barker, Stephen https://orca.cardiff.ac.uk/view/cardiffauthors/A015364W.html orcid:0000-0001-7870-6431 orcid:0000-0001-7870-6431, Zhang, Xu, Jonkers, Lukas, Lordsmith, Sian, Conn, Stephen and Knorr, Gregor 2021. Strengthening Atlantic inflow across the mid-pleistocene transition. Paleoceanography and Paleoclimatology 36 (4) , e2020PA004200. 10.1029/2020PA004200 https://doi.org/10.1029/2020PA004200 file https://orca.cardiff.ac.uk/id/eprint/140272/3/2020PA004200.pdf doi:10.1029/2020PA004200 |
op_rights |
cc_by |
op_doi |
https://doi.org/10.1029/2020PA004200 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
36 |
container_issue |
4 |
_version_ |
1768388978977800192 |