Antarctic Sea-Ice Variations from Satellite Sensing in Relation to Climate

1975 ◽  
Vol 15 (73) ◽  
pp. 417-427 ◽  
Author(s):  
W. F. Budd
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
Mean Temperature ◽  
Single Location ◽  
Scale Temperature ◽  
One Year ◽  
The Antarctic

AbstractAn analysis of records of annual mean temperatures around Antarctica shows large-scale anomalies of thousands of kilometers extent with typical variations of a deg from one year to another From 1967 on, composite satellite photographs are available which show considerable variation in the sea-ice extent in different years up to about 5º of latitude. These largest differences seem to persist over entire seasons. In general there seems to be considerable association between the region around the Antarctic with the coldest temperatures and the regions of greatest sea-ice extent. An analysis of long-term records at a single location near the edge of the Antarctic sea ice indicates a strong correlation between variations in the annual mean temperature and the duration of the sea ice, such that a change of 1 deg in the annual mean temperature corresponds to about 70 d variation in the duration of the sea ice. A relation is obtained between variations of annual mean temperature and the mean extent of the sea ice, viz. a 1 deg change corresponds to approximately 2.5º latitude variation in the maximum sea-ice extent. The magnitude of the variations in the sea-ice extent observed from the satellite data in comparison with the large-scale temperature anomalies is compatible with the above relations, although some rotational shifts appear to take place.

Antarctic Sea-Ice Variations from Satellite Sensing in Relation to Climate

1975 ◽  
Vol 15 (73) ◽  
pp. 417-427 ◽  
Author(s):  
W. F. Budd
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
Mean Temperature ◽  
Single Location ◽  
Scale Temperature ◽  
One Year ◽  
The Antarctic

AbstractAn analysis of records of annual mean temperatures around Antarctica shows large-scale anomalies of thousands of kilometers extent with typical variations of a deg from one year to another From 1967 on, composite satellite photographs are available which show considerable variation in the sea-ice extent in different years up to about 5º of latitude. These largest differences seem to persist over entire seasons. In general there seems to be considerable association between the region around the Antarctic with the coldest temperatures and the regions of greatest sea-ice extent. An analysis of long-term records at a single location near the edge of the Antarctic sea ice indicates a strong correlation between variations in the annual mean temperature and the duration of the sea ice, such that a change of 1 deg in the annual mean temperature corresponds to about 70 d variation in the duration of the sea ice. A relation is obtained between variations of annual mean temperature and the mean extent of the sea ice, viz. a 1 deg change corresponds to approximately 2.5º latitude variation in the maximum sea-ice extent. The magnitude of the variations in the sea-ice extent observed from the satellite data in comparison with the large-scale temperature anomalies is compatible with the above relations, although some rotational shifts appear to take place.

scholarly journals Brief communication: Increasing shortwave absorption over the Arctic Ocean is not balanced by trends in the Antarctic

2017 ◽  
Vol 11 (5) ◽  
pp. 2111-2116 ◽  
Author(s):  
Christian Katlein ◽  
Stefan Hendricks ◽  
Jeffrey Key
Keyword(s):  
Sea Ice ◽  
Cloud Cover ◽  
Arctic Sea Ice ◽  
Shortwave Radiation ◽  
The Arctic ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
Arctic Sea ◽  
The Antarctic

Abstract. On the basis of a new, consistent, long-term observational satellite dataset we show that, despite the observed increase of sea ice extent in the Antarctic, absorption of solar shortwave radiation in the Southern Ocean poleward of 60° latitude is not decreasing. The observations hence show that the small increase in Antarctic sea ice extent does not compensate for the combined effect of retreating Arctic sea ice and changes in cloud cover, which both result in a total increase in solar shortwave energy deposited into the polar oceans.

scholarly journals Inter-annual variations observed in spring and summer Antarctic sea ice extent in recent decade

MAUSAM ◽  
2021 ◽  
Vol 62 (4) ◽  
pp. 633-640
Author(s):  
SANDIP R.OZA ◽  
R.K.K. SINGH ◽  
ABHINAV SRIVASTAVA ◽  
MIHIR K.DASH ◽  
I.M.L. DAS ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Large Scale ◽  
Ross Sea ◽  
Ice Cover ◽  
Weddell Sea ◽  
The Arctic ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
The Antarctic

The growth and decay of sea ice are complex processes and have important feedback onto the oceanic and atmospheric circulation. In the Antarctic, sea ice variability significantly affects the primary productivity in the Southern Ocean and thereby negatively influences the performance and survival of species in polar ecosystem. In present days, the awareness on the sea ice variability in the Antarctic is not as matured as it is for the Arctic region. The present paper focuses on the inter-annual trends (1999-2009) observed in the monthly fractional sea ice cover in the Antarctic at 1 × 1 degree level, for the November and February months, derived from QuikSCAT scatterometer data. OSCAT scatterometer data from India’s Oceansat-2 satellite were used to asses the sea ice extent (SIE) observed in the month of November 2009 and February 2010 and its deviation from climatic maximum (1979-2002) sea ice extent (CMSIE). Large differences were observed between SIE and CMSIE, however, trend results show that it is due to the high inter-annual variability in sea ice cover. Spatial distribution of trends show the existence of positive and negative trends in the parts of Western Pacific Ocean, Ross Sea, Amundsen and Bellingshausen Seas (ABS), Weddell Sea and Indian ocean sector of southern ocean. Sea ice trends are compared with long-term SST trends (1982-2009) observed in the austral summer month of February. Large-scale cooling trend observed around Ross Sea and warming trend in ABS sector are the distinct outcome of the study.

scholarly journals Dark metabolism: a molecular insight into how the Antarctic sea‐ice diatom Fragilariopsis cylindrus survives long‐term darkness

2019 ◽  
Vol 223 (2) ◽  
pp. 675-691 ◽  
Author(s):  
Fraser Kennedy ◽  
Andrew Martin ◽  
John P. Bowman ◽  
Richard Wilson ◽  
Andrew McMinn
Keyword(s):  
Sea Ice ◽  
Antarctic Sea Ice ◽  
Fragilariopsis Cylindrus ◽  
Dark Metabolism ◽  
The Antarctic ◽  
Insight Into

Last Glacial Maximum Antarctic sea ice linked with global mean ocean temperature: evidence from PMIP3, PMIP4 and MIROC-4m simulations

2021 ◽  
Author(s):  
Tristan Vadsaria ◽  
Sam Sherriff-Tadano ◽  
Ayako Abe-Ouchi ◽  
Takashi Obase ◽  
Wing-Le Chan ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Last Glacial Maximum ◽  
Ocean Circulation ◽  
Glacial Maximum ◽  
Ocean Temperature ◽  
Sea Ice Extent ◽  
Last Glacial ◽  
Antarctic Sea Ice ◽  
The Antarctic

<p>Southern Ocean sea ice and oceanic fronts are known to play an important role on the climate system, carbon cycles, bottom ocean circulation, and Antarctic ice sheet. However, many models of the previous Past-climate Model Intercomparison Project (PMIP) underestimated sea-ice extent (SIE) for the Last Glacial Maximum (LGM)(Roche et al., 2012; Marzocchi and Jensen, 2017), mainly because of surface bias (Flato et al., 2013) that may have an impact on mean ocean temperature (MOT). Indeed, recent studies further suggest an important link between Southern Ocean sea ice and mean ocean temperature (Ferrari et al., 2014; Bereiter et al., 2018 among others). Misrepresent the Antarctic sea-ice extent could highly impact deep ocean circulation, the heat transport and thus the MOT. In this study, we will stress the relationship between the distribution of Antarctic sea-ice extent and the MOT through the analysis of the PMIP3 and PMIP4 exercise and by using a set of MIROC models. To date, the latest version of MIROC improve its representation of the LGM Antarctic sea-ice extent, affecting the deep circulation and the MOT distribution (Sherriff-Tadano et al., under review).</p><p>Our results show that available PMIP4 models have an overall improvement in term of LGM sea-ice extent compared to PMIP3, associated to colder deep and bottom ocean temperature. Focusing on MIROC (4m) models, we show that models accounting for Southern Ocean sea-surface temperature (SST) bias correction reproduce an Antarctic sea-ice extent, 2D-distribution, and seasonal amplitude in good agreement with proxy-based data. Finally, using PMIP-MIROC analyze, we show that it exists a relationship between the maximum SIE and the MOT, modulated by the Antarctic intermediate and bottom waters.</p>

scholarly journals Decadal trends in the Antarctic sea ice extent ultimately controlled by ice–ocean feedback

2014 ◽  
Vol 8 (2) ◽  
pp. 453-470 ◽  
Author(s):  
H. Goosse ◽  
V. Zunz
Keyword(s):  
Sea Ice ◽  
Mixed Layer Depth ◽  
Initial Perturbation ◽  
Salt Transport ◽  
Freshwater Flux ◽  
Positive Trend ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
Ice Concentration ◽  
The Antarctic

Abstract. The large natural variability of the Antarctic sea ice is a key characteristic of the system that might be responsible for the small positive trend in sea ice extent observed since 1979. In order to gain insight of the processes responsible for this variability, we have analysed in a control simulation performed with a coupled climate model a positive ice–ocean feedback that amplifies sea ice variations. When sea ice concentration increases in a region, in particular close to the ice edge, the mixed layer depth tends to decrease. This can be caused by a net inflow of ice, and thus of freshwater, that stabilizes the water column. A second stabilizing mechanism at interannual timescales is associated with the downward salt transport due to the seasonal cycle of ice formation: brine is released in winter and mixed over a deep layer while the freshwater flux caused by ice melting is included in a shallow layer, resulting in a net vertical transport of salt. Because of this stronger stratification due to the presence of sea ice, more heat is stored at depth in the ocean and the vertical oceanic heat flux is reduced, which contributes to maintaining a higher ice extent. This positive feedback is not associated with a particular spatial pattern. Consequently, the spatial distribution of the trend in ice concentration is largely imposed by the wind changes that can provide the initial perturbation. A positive freshwater flux could alternatively be the initial trigger but the amplitude of the final response of the sea ice extent is finally set up by the amplification related to the ice–ocean feedback. Initial conditions also have an influence as the chance to have a large increase in ice extent is higher if starting from a state characterized by a low value.

scholarly journals Positive Trend in the Antarctic Sea Ice Cover and Associated Changes in Surface Temperature

2017 ◽  
Vol 30 (6) ◽  
pp. 2251-2267 ◽  
Author(s):  
Josefino C. Comiso ◽  
Robert A. Gersten ◽  
Larry V. Stock ◽  
John Turner ◽  
Gay J. Perez ◽  
...  
Keyword(s):  
Sea Ice ◽  
Surface Temperature ◽  
Climate Models ◽  
Ice Cover ◽  
Southern Annular Mode ◽  
Positive Trend ◽  
Growth Season ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
The Antarctic

Abstract The Antarctic sea ice extent has been slowly increasing contrary to expected trends due to global warming and results from coupled climate models. After a record high extent in 2012 the extent was even higher in 2014 when the magnitude exceeded 20 × 106 km2 for the first time during the satellite era. The positive trend is confirmed with newly reprocessed sea ice data that addressed inconsistency issues in the time series. The variability in sea ice extent and ice area was studied alongside surface ice temperature for the 34-yr period starting in 1981, and the results of the analysis show a strong correlation of −0.94 during the growth season and −0.86 during the melt season. The correlation coefficients are even stronger with a one-month lag in surface temperature at −0.96 during the growth season and −0.98 during the melt season, suggesting that the trend in sea ice cover is strongly influenced by the trend in surface temperature. The correlation with atmospheric circulation as represented by the southern annular mode (SAM) index appears to be relatively weak. A case study comparing the record high in 2014 with a relatively low ice extent in 2015 also shows strong sensitivity to changes in surface temperature. The results suggest that the positive trend is a consequence of the spatial variability of global trends in surface temperature and that the ability of current climate models to forecast sea ice trend can be improved through better performance in reproducing observed surface temperatures in the Antarctic region.

scholarly journals Brief communication: Antarctic sea ice gain does not compensate for increased solar absorption from Arctic ice loss

2017 ◽  
Author(s):  
Christian Katlein ◽  
Stefan Hendricks ◽  
Jeffrey Key
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Radiation Budget ◽  
Shortwave Radiation ◽  
Sea Ice Extent ◽  
Solar Absorption ◽  
Antarctic Sea Ice ◽  
Polar Oceans ◽  
Arctic Ice ◽  
The Antarctic

Abstract. Here we show on the basis of the new consistent long-term observational dataset APP-x, that the observed increase of sea ice extent in the Antarctic cannot compensate for the loss of Arctic sea ice in terms of the shortwave radiation budget in the polar oceans poleward of 50° latitude. The observations show, that apart from retreating sea-ice additional effects like albedo changes and especially changing cloud coverage lead to a total increase of solar shortwave energy deposited into the polar oceans despite of the marginal increase in Antarctic winter sea ice extent.

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