Characteristics of Surface "Melt Potential" over Antarctic Ice Shelves based on Regional Atmospheric Model Simulations of Summer Air Temperature Extremes from 1979/80 to 2018/19
We calculate a regional surface “melt potential” index (MPI) over Antarctic ice shelves that describes the frequency (MPI-freq; %) and intensity (MPI-int; K) of daily maximum summer temperatures exceeding a melt threshold of 273.15 K. This is used to determine which ice shelves are vulnerable to mel...
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Language: | English |
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Online Access: | https://doi.org/10.1175/JCLI-D-22-0386.1 |
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ftzenodo:oai:zenodo.org:8064519 2024-09-15T17:46:00+00:00 Characteristics of Surface "Melt Potential" over Antarctic Ice Shelves based on Regional Atmospheric Model Simulations of Summer Air Temperature Extremes from 1979/80 to 2018/19 Orr, Andrew Deb, Pranab Clem, Kyle R. Gilbert, Ella Bromwich, David H. Boberg, Fredrik Colwell, Steve Hansen, Nicolaj Lazzara, Matthew A. Mooney, Priscilla A. Mottram, Ruth Niwano, Masashi Phillips, Tony Pishniak, Denys Reijmer, Carleen H. van der Berg, Willem Jan Webster, Stuart Zou, Xun 2023-04-28 https://doi.org/10.1175/JCLI-D-22-0386.1 eng eng Zenodo https://zenodo.org/communities/polarres https://zenodo.org/communities/eu https://doi.org/10.1175/JCLI-D-22-0386.1 oai:zenodo.org:8064519 info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode info:eu-repo/semantics/article 2023 ftzenodo https://doi.org/10.1175/JCLI-D-22-0386.1 2024-07-25T20:45:48Z We calculate a regional surface “melt potential” index (MPI) over Antarctic ice shelves that describes the frequency (MPI-freq; %) and intensity (MPI-int; K) of daily maximum summer temperatures exceeding a melt threshold of 273.15 K. This is used to determine which ice shelves are vulnerable to melt-induced hydrofracture and is calculated using near-surface temperature output for each summer from 1979/80 to 2018/19 from two high-resolution regional atmospheric model hindcasts (using the MetUM and HIRHAM5). MPI is highest for Antarctic Peninsula ice shelves (MPI-freq 23%–35%, MPI-int 1.2–2.1 K), lowest (2%–3%, <0 K) for the Ronne–Filchner and Ross ice shelves, and around 10%–24% and 0.6–1.7 K for the other West and East Antarctic ice shelves. Hotspots of MPI are apparent over many ice shelves, and they also show a decreasing trend in MPI-freq. The regional circulation patterns associated with high MPI values over West and East Antarctic ice shelves are remarkably consistent for their respective region but tied to different large-scale climate forcings. The West Antarctic circulation resembles the central Pacific El Niño pattern with a stationary Rossby wave and a strong anticyclone over the high-latitude South Pacific. By contrast, the East Antarctic circulation comprises a zonally symmetric negative Southern Annular Mode pattern with a strong regional anticyclone on the plateau and enhanced coastal easterlies/weakened Southern Ocean westerlies. Values of MPI are 3–4 times larger for a lower temperature/melt threshold of 271.15 K used in a sensitivity test, as melting can occur at temperatures lower than 273.15 K depending on snowpack properties. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Ice Shelves Southern Ocean Zenodo Journal of Climate 36 10 3357 3383 |
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Open Polar |
collection |
Zenodo |
op_collection_id |
ftzenodo |
language |
English |
description |
We calculate a regional surface “melt potential” index (MPI) over Antarctic ice shelves that describes the frequency (MPI-freq; %) and intensity (MPI-int; K) of daily maximum summer temperatures exceeding a melt threshold of 273.15 K. This is used to determine which ice shelves are vulnerable to melt-induced hydrofracture and is calculated using near-surface temperature output for each summer from 1979/80 to 2018/19 from two high-resolution regional atmospheric model hindcasts (using the MetUM and HIRHAM5). MPI is highest for Antarctic Peninsula ice shelves (MPI-freq 23%–35%, MPI-int 1.2–2.1 K), lowest (2%–3%, <0 K) for the Ronne–Filchner and Ross ice shelves, and around 10%–24% and 0.6–1.7 K for the other West and East Antarctic ice shelves. Hotspots of MPI are apparent over many ice shelves, and they also show a decreasing trend in MPI-freq. The regional circulation patterns associated with high MPI values over West and East Antarctic ice shelves are remarkably consistent for their respective region but tied to different large-scale climate forcings. The West Antarctic circulation resembles the central Pacific El Niño pattern with a stationary Rossby wave and a strong anticyclone over the high-latitude South Pacific. By contrast, the East Antarctic circulation comprises a zonally symmetric negative Southern Annular Mode pattern with a strong regional anticyclone on the plateau and enhanced coastal easterlies/weakened Southern Ocean westerlies. Values of MPI are 3–4 times larger for a lower temperature/melt threshold of 271.15 K used in a sensitivity test, as melting can occur at temperatures lower than 273.15 K depending on snowpack properties. |
format |
Article in Journal/Newspaper |
author |
Orr, Andrew Deb, Pranab Clem, Kyle R. Gilbert, Ella Bromwich, David H. Boberg, Fredrik Colwell, Steve Hansen, Nicolaj Lazzara, Matthew A. Mooney, Priscilla A. Mottram, Ruth Niwano, Masashi Phillips, Tony Pishniak, Denys Reijmer, Carleen H. van der Berg, Willem Jan Webster, Stuart Zou, Xun |
spellingShingle |
Orr, Andrew Deb, Pranab Clem, Kyle R. Gilbert, Ella Bromwich, David H. Boberg, Fredrik Colwell, Steve Hansen, Nicolaj Lazzara, Matthew A. Mooney, Priscilla A. Mottram, Ruth Niwano, Masashi Phillips, Tony Pishniak, Denys Reijmer, Carleen H. van der Berg, Willem Jan Webster, Stuart Zou, Xun Characteristics of Surface "Melt Potential" over Antarctic Ice Shelves based on Regional Atmospheric Model Simulations of Summer Air Temperature Extremes from 1979/80 to 2018/19 |
author_facet |
Orr, Andrew Deb, Pranab Clem, Kyle R. Gilbert, Ella Bromwich, David H. Boberg, Fredrik Colwell, Steve Hansen, Nicolaj Lazzara, Matthew A. Mooney, Priscilla A. Mottram, Ruth Niwano, Masashi Phillips, Tony Pishniak, Denys Reijmer, Carleen H. van der Berg, Willem Jan Webster, Stuart Zou, Xun |
author_sort |
Orr, Andrew |
title |
Characteristics of Surface "Melt Potential" over Antarctic Ice Shelves based on Regional Atmospheric Model Simulations of Summer Air Temperature Extremes from 1979/80 to 2018/19 |
title_short |
Characteristics of Surface "Melt Potential" over Antarctic Ice Shelves based on Regional Atmospheric Model Simulations of Summer Air Temperature Extremes from 1979/80 to 2018/19 |
title_full |
Characteristics of Surface "Melt Potential" over Antarctic Ice Shelves based on Regional Atmospheric Model Simulations of Summer Air Temperature Extremes from 1979/80 to 2018/19 |
title_fullStr |
Characteristics of Surface "Melt Potential" over Antarctic Ice Shelves based on Regional Atmospheric Model Simulations of Summer Air Temperature Extremes from 1979/80 to 2018/19 |
title_full_unstemmed |
Characteristics of Surface "Melt Potential" over Antarctic Ice Shelves based on Regional Atmospheric Model Simulations of Summer Air Temperature Extremes from 1979/80 to 2018/19 |
title_sort |
characteristics of surface "melt potential" over antarctic ice shelves based on regional atmospheric model simulations of summer air temperature extremes from 1979/80 to 2018/19 |
publisher |
Zenodo |
publishDate |
2023 |
url |
https://doi.org/10.1175/JCLI-D-22-0386.1 |
genre |
Antarc* Antarctic Antarctic Peninsula Ice Shelves Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Ice Shelves Southern Ocean |
op_relation |
https://zenodo.org/communities/polarres https://zenodo.org/communities/eu https://doi.org/10.1175/JCLI-D-22-0386.1 oai:zenodo.org:8064519 |
op_rights |
info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode |
op_doi |
https://doi.org/10.1175/JCLI-D-22-0386.1 |
container_title |
Journal of Climate |
container_volume |
36 |
container_issue |
10 |
container_start_page |
3357 |
op_container_end_page |
3383 |
_version_ |
1810493953436286976 |