Projecting the evolution of Totten Glacier, East Antarctica, over the 21st century using ice-ocean coupled models
Totten Glacier, the primary ice discharger of the East Antarctic Ice Sheet (EAIS), contains 3.85 m sea level rise equivalent ice mass (SLRe) and has displayed dynamic change driven by interaction of its ice shelf with the Southern Ocean. To project Totten Glacier's evolution, it is critical tha...
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2021
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ftcdlib:oai:escholarship.org/ark:/13030/qt1mm588j4 2023-05-15T13:35:40+02:00 Projecting the evolution of Totten Glacier, East Antarctica, over the 21st century using ice-ocean coupled models Pelle, Tyler Morlighem, Mathieu 2021-01-01 application/pdf https://escholarship.org/uc/item/1mm588j4 en eng eScholarship, University of California qt1mm588j4 https://escholarship.org/uc/item/1mm588j4 CC-BY CC-BY Geophysics Environmental science Antarctica basal melting ice dynamics ice sheet modeling etd 2021 ftcdlib 2021-07-05T17:07:30Z Totten Glacier, the primary ice discharger of the East Antarctic Ice Sheet (EAIS), contains 3.85 m sea level rise equivalent ice mass (SLRe) and has displayed dynamic change driven by interaction of its ice shelf with the Southern Ocean. To project Totten Glacier's evolution, it is critical that sub-shelf ocean processes are properly resolved in dynamic ice sheet models. First, we combine an ocean box model with a buoyant plume parameterization to create PICOP, a novel melt parameterization that resolves sub-shelf vertical overturning and produces melt rates that are in excellent agreement with observations. We then use this parameterization to make century-scale mass balance projections of the EAIS, forced by surface mass balance and ocean thermal anomalies from ten global climate models. Although increased snowfall offsets ice discharge in high emission scenarios and results in ~10 mm SLRe gain by 2100, significant grounded ice thinning (1.15 m/yr) and mass loss (~6 mm SLRe) from Totten Glacier is projected. To investigate whether PICOP misses important processes, such as the advection of warm water into the ice shelf cavity, we develop a fully coupled ice-ocean model and find that warm water is able to access Totten Glacier's sub-shelf cavity through topographic depressions along the central and eastern calving front. By mid-century in high emission scenarios, warm water intrusions become strong enough to overcome topographic barriers and dislodge Totten Glacier's southern grounding line, triggering abrupt acceleration in ice discharge (+185%). Overall, the timing and extent of Totten Glacier's retreat is predominately controlled by the sub-shelf ocean circulation, highlighting the importance of studying dynamic glaciers in fully coupled ice-ocean models. Other/Unknown Material Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Southern Ocean Totten Glacier University of California: eScholarship Antarctic East Antarctic Ice Sheet East Antarctica Southern Ocean Totten Glacier ENVELOPE(116.333,116.333,-66.833,-66.833) |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
topic |
Geophysics Environmental science Antarctica basal melting ice dynamics ice sheet modeling |
spellingShingle |
Geophysics Environmental science Antarctica basal melting ice dynamics ice sheet modeling Pelle, Tyler Projecting the evolution of Totten Glacier, East Antarctica, over the 21st century using ice-ocean coupled models |
topic_facet |
Geophysics Environmental science Antarctica basal melting ice dynamics ice sheet modeling |
description |
Totten Glacier, the primary ice discharger of the East Antarctic Ice Sheet (EAIS), contains 3.85 m sea level rise equivalent ice mass (SLRe) and has displayed dynamic change driven by interaction of its ice shelf with the Southern Ocean. To project Totten Glacier's evolution, it is critical that sub-shelf ocean processes are properly resolved in dynamic ice sheet models. First, we combine an ocean box model with a buoyant plume parameterization to create PICOP, a novel melt parameterization that resolves sub-shelf vertical overturning and produces melt rates that are in excellent agreement with observations. We then use this parameterization to make century-scale mass balance projections of the EAIS, forced by surface mass balance and ocean thermal anomalies from ten global climate models. Although increased snowfall offsets ice discharge in high emission scenarios and results in ~10 mm SLRe gain by 2100, significant grounded ice thinning (1.15 m/yr) and mass loss (~6 mm SLRe) from Totten Glacier is projected. To investigate whether PICOP misses important processes, such as the advection of warm water into the ice shelf cavity, we develop a fully coupled ice-ocean model and find that warm water is able to access Totten Glacier's sub-shelf cavity through topographic depressions along the central and eastern calving front. By mid-century in high emission scenarios, warm water intrusions become strong enough to overcome topographic barriers and dislodge Totten Glacier's southern grounding line, triggering abrupt acceleration in ice discharge (+185%). Overall, the timing and extent of Totten Glacier's retreat is predominately controlled by the sub-shelf ocean circulation, highlighting the importance of studying dynamic glaciers in fully coupled ice-ocean models. |
author2 |
Morlighem, Mathieu |
format |
Other/Unknown Material |
author |
Pelle, Tyler |
author_facet |
Pelle, Tyler |
author_sort |
Pelle, Tyler |
title |
Projecting the evolution of Totten Glacier, East Antarctica, over the 21st century using ice-ocean coupled models |
title_short |
Projecting the evolution of Totten Glacier, East Antarctica, over the 21st century using ice-ocean coupled models |
title_full |
Projecting the evolution of Totten Glacier, East Antarctica, over the 21st century using ice-ocean coupled models |
title_fullStr |
Projecting the evolution of Totten Glacier, East Antarctica, over the 21st century using ice-ocean coupled models |
title_full_unstemmed |
Projecting the evolution of Totten Glacier, East Antarctica, over the 21st century using ice-ocean coupled models |
title_sort |
projecting the evolution of totten glacier, east antarctica, over the 21st century using ice-ocean coupled models |
publisher |
eScholarship, University of California |
publishDate |
2021 |
url |
https://escholarship.org/uc/item/1mm588j4 |
long_lat |
ENVELOPE(116.333,116.333,-66.833,-66.833) |
geographic |
Antarctic East Antarctic Ice Sheet East Antarctica Southern Ocean Totten Glacier |
geographic_facet |
Antarctic East Antarctic Ice Sheet East Antarctica Southern Ocean Totten Glacier |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Southern Ocean Totten Glacier |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Southern Ocean Totten Glacier |
op_relation |
qt1mm588j4 https://escholarship.org/uc/item/1mm588j4 |
op_rights |
CC-BY |
op_rightsnorm |
CC-BY |
_version_ |
1766068660443545600 |