Local atmospheric response to an open-ocean polynya in a high-resolution climate model
In this paper we study the atmospheric response to an open-ocean polynya in the Southern Ocean by analyzing the results from an atmospheric and oceanic synoptic-scale resolving Community Earth System Model (CESM) simulation. While coarser-resolution versions of CESM generally do not produce open-oce...
Published in: | Journal of Climate |
---|---|
Main Authors: | , , , , , , , |
Language: | unknown |
Published: |
2021
|
Subjects: | |
Online Access: | http://www.osti.gov/servlets/purl/1346290 https://www.osti.gov/biblio/1346290 https://doi.org/10.1175/JCLI-D-16-0120.1 |
id |
ftosti:oai:osti.gov:1346290 |
---|---|
record_format |
openpolar |
spelling |
ftosti:oai:osti.gov:1346290 2023-07-30T04:06:47+02:00 Local atmospheric response to an open-ocean polynya in a high-resolution climate model Weijer, Wilbert Veneziani, Milena Stössel, Achim Hecht, Matthew W. Jeffery, Nicole Jonko, Alexandra Hodos, Travis Wang, Hailong 2021-07-23 application/pdf http://www.osti.gov/servlets/purl/1346290 https://www.osti.gov/biblio/1346290 https://doi.org/10.1175/JCLI-D-16-0120.1 unknown http://www.osti.gov/servlets/purl/1346290 https://www.osti.gov/biblio/1346290 https://doi.org/10.1175/JCLI-D-16-0120.1 doi:10.1175/JCLI-D-16-0120.1 54 ENVIRONMENTAL SCIENCES 2021 ftosti https://doi.org/10.1175/JCLI-D-16-0120.1 2023-07-11T09:17:31Z In this paper we study the atmospheric response to an open-ocean polynya in the Southern Ocean by analyzing the results from an atmospheric and oceanic synoptic-scale resolving Community Earth System Model (CESM) simulation. While coarser-resolution versions of CESM generally do not produce open-ocean polynyas in the Southern Ocean, they do emerge and disappear on interannual timescales in the synoptic-scale simulation. This provides an ideal opportunity to study the polynya’s impact on the overlying and surrounding atmosphere. This has been pursued here by investigating the seasonal cycle of differences of surface and air-column variables between polynya and nonpolynya years. Our results indicate significant local impacts on turbulent heat fluxes, precipitation, cloud characteristics, and radiative fluxes. In particular, we find that clouds over polynyas are optically thicker and higher than clouds over sea ice during non-polynya years. Although the lower albedo of polynyas significantly increases the net shortwave absorption, the enhanced cloud brightness tempers this increase by almost 50%. Also, in this model, enhanced longwave radiation emitted from the warmer surface of polynyas is balanced by stronger downwelling fluxes from the thicker cloud deck. Impacts are found to be sensitive to the synoptic wind direction. Strongest regional impacts are found when northeasterly winds cross the polynya and interact with katabatic winds. As a result, surface air pressure anomalies over the polynya are only found to be significant when cold, dry air masses strike over the polynya, i.e. in case of southerly winds. Other/Unknown Material Sea ice Southern Ocean SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Southern Ocean Journal of Climate 30 5 1629 1641 |
institution |
Open Polar |
collection |
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
spellingShingle |
54 ENVIRONMENTAL SCIENCES Weijer, Wilbert Veneziani, Milena Stössel, Achim Hecht, Matthew W. Jeffery, Nicole Jonko, Alexandra Hodos, Travis Wang, Hailong Local atmospheric response to an open-ocean polynya in a high-resolution climate model |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
In this paper we study the atmospheric response to an open-ocean polynya in the Southern Ocean by analyzing the results from an atmospheric and oceanic synoptic-scale resolving Community Earth System Model (CESM) simulation. While coarser-resolution versions of CESM generally do not produce open-ocean polynyas in the Southern Ocean, they do emerge and disappear on interannual timescales in the synoptic-scale simulation. This provides an ideal opportunity to study the polynya’s impact on the overlying and surrounding atmosphere. This has been pursued here by investigating the seasonal cycle of differences of surface and air-column variables between polynya and nonpolynya years. Our results indicate significant local impacts on turbulent heat fluxes, precipitation, cloud characteristics, and radiative fluxes. In particular, we find that clouds over polynyas are optically thicker and higher than clouds over sea ice during non-polynya years. Although the lower albedo of polynyas significantly increases the net shortwave absorption, the enhanced cloud brightness tempers this increase by almost 50%. Also, in this model, enhanced longwave radiation emitted from the warmer surface of polynyas is balanced by stronger downwelling fluxes from the thicker cloud deck. Impacts are found to be sensitive to the synoptic wind direction. Strongest regional impacts are found when northeasterly winds cross the polynya and interact with katabatic winds. As a result, surface air pressure anomalies over the polynya are only found to be significant when cold, dry air masses strike over the polynya, i.e. in case of southerly winds. |
author |
Weijer, Wilbert Veneziani, Milena Stössel, Achim Hecht, Matthew W. Jeffery, Nicole Jonko, Alexandra Hodos, Travis Wang, Hailong |
author_facet |
Weijer, Wilbert Veneziani, Milena Stössel, Achim Hecht, Matthew W. Jeffery, Nicole Jonko, Alexandra Hodos, Travis Wang, Hailong |
author_sort |
Weijer, Wilbert |
title |
Local atmospheric response to an open-ocean polynya in a high-resolution climate model |
title_short |
Local atmospheric response to an open-ocean polynya in a high-resolution climate model |
title_full |
Local atmospheric response to an open-ocean polynya in a high-resolution climate model |
title_fullStr |
Local atmospheric response to an open-ocean polynya in a high-resolution climate model |
title_full_unstemmed |
Local atmospheric response to an open-ocean polynya in a high-resolution climate model |
title_sort |
local atmospheric response to an open-ocean polynya in a high-resolution climate model |
publishDate |
2021 |
url |
http://www.osti.gov/servlets/purl/1346290 https://www.osti.gov/biblio/1346290 https://doi.org/10.1175/JCLI-D-16-0120.1 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Sea ice Southern Ocean |
genre_facet |
Sea ice Southern Ocean |
op_relation |
http://www.osti.gov/servlets/purl/1346290 https://www.osti.gov/biblio/1346290 https://doi.org/10.1175/JCLI-D-16-0120.1 doi:10.1175/JCLI-D-16-0120.1 |
op_doi |
https://doi.org/10.1175/JCLI-D-16-0120.1 |
container_title |
Journal of Climate |
container_volume |
30 |
container_issue |
5 |
container_start_page |
1629 |
op_container_end_page |
1641 |
_version_ |
1772819686879133696 |