Decadal Scale Variability of Larsen Ice Shelf Melt Captured by Antarctic Peninsula Ice Core

In this study, we used the stable water isotope record (δ 18 O) from an ice core drilled in Palmer Land, southern Antarctic Peninsula (AP). Utilizing δ 18 O we identified two climate regimes during the satellite era. During the 1979–1998 positive interdecadal Pacific oscillation (IPO) phase, a low-p...

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Bibliographic Details
Published in:Geosciences
Main Authors: B. Daniel Emanuelsson, Elizabeth R. Thomas, Jack D. Humby, Diana O. Vladimirova
Format: Article in Journal/Newspaper
Language:English
Published: MDPI AG 2022
Subjects:
ice shelf melt
decadal-scale variability
interdecadal Pacific oscillation (IPO)
water stable isotopes
ice cores
Antarctic Peninsula
Geology
QE1-996.5
Antarctic
Bellingshausen Sea
Drake Passage
Larsen Ice Shelf
Pacific
Palmer Land
Southern Ocean
Weddell
Weddell Sea
Antarc*
ice core
Ice Shelf
Sea ice
Online Access:https://doi.org/10.3390/geosciences12090344
https://doaj.org/article/979e460ff9c9423e974ab112114b3d93
Description
Summary:In this study, we used the stable water isotope record (δ 18 O) from an ice core drilled in Palmer Land, southern Antarctic Peninsula (AP). Utilizing δ 18 O we identified two climate regimes during the satellite era. During the 1979–1998 positive interdecadal Pacific oscillation (IPO) phase, a low-pressure system north of the Weddell Sea drove southeasterly winds that are associated with an increase in warm air mass intrusion onto the Larsen shelves, which melted and a decreased sea ice concentration in the Weddell Sea/increase in the Bellingshausen Sea. This climate setting is associated with anomaly low δ 18 O values (compared with the latter IPO period). There is significantly more melt along the northern AP ice shelf margins and on the Larsen D and southern Larsen C during the 1979–1998 IPO positive phase. The IPO positive climatic setting was coincidental with the Larsen A ice shelf collapse. In contrast, during the IPO negative phase (1999–2011), northerly winds caused a reduction in sea ice in the Bellingshausen Sea/Drake Passage region. Moreover, a Southern Ocean north of the Weddell Sea high-pressure system caused low-latitude warm humid air over the tip and east of the AP, a setting that is associated with increased northern AP snowfall, a high δ 18 O anomaly, and less prone to Larsen ice shelf melt.

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