First record of the occurrence of sea ice in the Cordillera Darwin fjords (54°S), Chile

Abstract This paper provides the first evidence for sea-ice formation in the Cordillera Darwin (CD) fjords in southern Chile, which is farther north than sea ice has previously been reported for the Southern Hemisphere. Initially observed from a passenger plane in September 2015, the presence of sea ice was then confirmed by aerial reconnaissance and subsequently identified in satellite imagery. A time series of Sentinel-1 and Landsat-8 images during austral winter 2015 was used to examine the chronology of sea-ice formation in the Cuevas fjord. A longer time series of imagery across the CD was analyzed from 2000 to 2017 and revealed that sea ice had formed in each of the 13 fjords during at least one winter and was present in some fjords during a majority of the years. Sea ice is more common in the northern end of the CD, compared to the south where sea ice is not typically present. Is suggested that surface freshening from melting glaciers and high precipitation reduces surface salinity and promotes sea-ice formation within the semi-enclosed fjord system during prolonged periods of cold air temperatures. This is a unique set of initial observations that identify questions for future research in this remote area.

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Multi-year particle fluxes in Kongsfjorden, Svalbard

Biogeosciences ◽

10.5194/bg-15-5343-2018 ◽

2018 ◽

Vol 15 (17) ◽

pp. 5343-5363 ◽

Cited By ~ 12

Author(s):

Alessandra D'Angelo ◽

Federico Giglio ◽

Stefano Miserocchi ◽

Anna Sanchez-Vidal ◽

Stefano Aliani ◽

...

Keyword(s):

Time Series ◽

Sea Ice ◽

Ocean Circulation ◽

Progressive Increase ◽

Physical Parameters ◽

Air Temperatures ◽

Inorganic Matter ◽

Particle Fluxes ◽

Particulate Fluxes ◽

Over Time

Abstract. High-latitude regions are warming faster than other areas due to reduction of snow cover and sea ice loss and changes in atmospheric and ocean circulation. The combination of these processes, collectively known as polar amplification, provides an extraordinary opportunity to document the ongoing thermal destabilisation of the terrestrial cryosphere and the release of land-derived material into the aquatic environment. This study presents a 6-year time series (2010–2016) of physical parameters and particle fluxes collected by an oceanographic mooring in Kongsfjorden (Spitsbergen, Svalbard). In recent decades, Kongsfjorden has been experiencing rapid loss of sea ice coverage and retreat of local glaciers as a result of the progressive increase in ocean and air temperatures. The overarching goal of this study was to continuously monitor the inner fjord particle sinking and to understand to what extent the temporal evolution of particulate fluxes was linked to the progressive changes in both Atlantic and freshwater input. Our data show high peaks of settling particles during warm seasons, in terms of both organic and inorganic matter. The different sources of suspended particles were described as a mixing of glacier carbonate, glacier siliciclastic and autochthonous marine input. The glacier releasing sediments into the fjord was the predominant source, while the sediment input by rivers was reduced at the mooring site. Our time series showed that the seasonal sunlight exerted first-order control on the particulate fluxes in the inner fjord. The marine fraction peaked when the solar radiation was at a maximum in May–June while the land-derived fluxes exhibited a 1–2-month lag consistent with the maximum air temperature and glacier melting. The inter-annual time-weighted total mass fluxes varied by 2 orders of magnitude over time, with relatively higher values in 2011, 2013, and 2015. Our results suggest that the land-derived input will remarkably increase over time in a warming scenario. Further studies are therefore needed to understand the future response of the Kongsfjorden ecosystem alterations with respect to the enhanced release of glacier-derived material.

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Human geographies of sea ice: freeze/thaw processes around Cape Dorset, Nunavut, Canada

Polar Record ◽

10.1017/s0032247407007061 ◽

2008 ◽

Vol 44 (1) ◽

pp. 51-76 ◽

Cited By ~ 35

Author(s):

Gita J. Laidler ◽

Pootoogoo Elee

Keyword(s):

Sea Ice ◽

Regional Scale ◽

Open Water ◽

Current Strength ◽

Ice Formation ◽

Future Research ◽

Baffin Island ◽

Freeze Thaw ◽

Ice Conditions ◽

Inuit Knowledge

ABSTRACTSea ice has been, and continues to be, an integral component of life in the Inuit community of Cape Dorset, Nunavut. Located on an island of the same name off the southwestern coast of Baffin Island, the strong Hudson Strait currents prevent extensive ice formation around the community. Nevertheless, sea ice remains an important travel and hunting platform, enabling access to Baffin Island, hunting and fishing grounds, and nearby communities. With the combined importance, dynamism, and continuous use of this frozen ocean environment, local Inuit elders and hunters have developed a detailed and nuanced understanding of sea ice conditions, freeze/thaw processes, and the influences of winds and currents on ice conditions. Working collaboratively with the community of Cape Dorset since October, 2003, we present the results of 30 semi-directed interviews, 5 sea ice trips, and 2 focus groups to provide a baseline understanding of local freezing processes (near-shore, open water, sea ice thickening, landfast ice, floe edge, and tidal cracks), melting processes (snow melt, water accumulation and drainage, break-up, and cracks/leads), wind influences on sea ice (wind direction and strength affecting sea ice formation, and movement), and current influences on sea ice (tidal variations and current strength affecting sea ice formation, movement, and polynya size/location). Strong emphasis is placed on Inuktitut terminology and spatial delineations of localised ice conditions and features. Therefore, this paper provides insights into local scale ice conditions and dynamics around Cape Dorset that are not captured in regional scale studies of Hudson Bay and/or Hudson Strait. Results have the potential to inform future research efforts on local/regional sea ice monitoring, the relationship between Inuit knowledge, language, and the environment, and addressing community interests through targeted studies.

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A large set of potential past, present and future hydro-meteorological time series for the UK

Hydrology and Earth System Sciences ◽

10.5194/hess-22-611-2018 ◽

2018 ◽

Vol 22 (1) ◽

pp. 611-634 ◽

Cited By ~ 22

Author(s):

Benoit P. Guillod ◽

Richard G. Jones ◽

Simon J. Dadson ◽

Gemma Coxon ◽

Gianbattista Bussi ◽

...

Keyword(s):

Time Series ◽

Sea Ice ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Climate Model ◽

Sea Surface ◽

Large Set ◽

Future Scenarios ◽

High Precipitation ◽

The Uk

Abstract. Hydro-meteorological extremes such as drought and heavy precipitation can have large impacts on society and the economy. With potentially increasing risks associated with such events due to climate change, properly assessing the associated impacts and uncertainties is critical for adequate adaptation. However, the application of risk-based approaches often requires large sets of extreme events, which are not commonly available. Here, we present such a large set of hydro-meteorological time series for recent past and future conditions for the United Kingdom based on weather@home 2, a modelling framework consisting of a global climate model (GCM) driven by observed or projected sea surface temperature (SST) and sea ice which is downscaled to 25 km over the European domain by a regional climate model (RCM). Sets of 100 time series are generated for each of (i) a historical baseline (1900–2006), (ii) five near-future scenarios (2020–2049) and (iii) five far-future scenarios (2070–2099). The five scenarios in each future time slice all follow the Representative Concentration Pathway 8.5 (RCP8.5) and sample the range of sea surface temperature and sea ice changes from CMIP5 (Coupled Model Intercomparison Project Phase 5) models. Validation of the historical baseline highlights good performance for temperature and potential evaporation, but substantial seasonal biases in mean precipitation, which are corrected using a linear approach. For extremes in low precipitation over a long accumulation period (>3 months) and shorter-duration high precipitation (1–30 days), the time series generally represents past statistics well. Future projections show small precipitation increases in winter but large decreases in summer on average, leading to an overall drying, consistently with the most recent UK Climate Projections (UKCP09) but larger in magnitude than the latter. Both drought and high-precipitation events are projected to increase in frequency and intensity in most regions, highlighting the need for appropriate adaptation measures. Overall, the presented dataset is a useful tool for assessing the risk associated with drought and more generally with hydro-meteorological extremes in the UK.

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Oceanic response to changes in the WAIS and astronomical forcing during the MIS31 superinterglacial

Climate of the Past ◽

10.5194/cp-13-1081-2017 ◽

2017 ◽

Vol 13 (9) ◽

pp. 1081-1095 ◽

Cited By ~ 1

Author(s):

Flavio Justino ◽

Douglas Lindemann ◽

Fred Kucharski ◽

Aaron Wilson ◽

David Bromwich ◽

...

Keyword(s):

Sea Ice ◽

Weddell Sea ◽

Meridional Overturning Circulation ◽

Surface Salinity ◽

West Antarctic Ice Sheet ◽

Orbital Parameters ◽

West Antarctic ◽

Air Temperatures ◽

The Pacific ◽

Oceanic Response

Abstract. Marine Isotope Stage 31 (MIS31, between 1085 and 1055 ka) was characterized by higher extratropical air temperatures and a substantial recession of polar glaciers compared to today. Paleoreconstructions and model simulations have increased the understanding of the MIS31 interval, but questions remain regarding the role of the Atlantic and Pacific oceans in modifying the climate associated with the variations in Earth's orbital parameters. Multi-century coupled climate simulations, with the astronomical configuration of the MIS31 and modified West Antarctic Ice Sheet (WAIS) topography, show an increase in the thermohaline flux and northward oceanic heat transport (OHT) in the Pacific Ocean. These oceanic changes are driven by anomalous atmospheric circulation and increased surface salinity in concert with a stronger meridional overturning circulation (MOC). The intensified northward OHT is responsible for up to 85 % of the global OHT anomalies and contributes to the overall reduction in sea ice in the Northern Hemisphere (NH) due to Earth's astronomical configuration. The relative contributions of the Atlantic Ocean to global OHT and MOC anomalies are minor compared to those of the Pacific. However, sea ice changes are remarkable, highlighted by decreased (increased) cover in the Ross (Weddell) Sea but widespread reductions in sea ice across the NH.

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A large set of potential past, present and future hydro-meteorological time series for the UK

10.5194/hess-2017-246 ◽

2017 ◽

Cited By ~ 2

Author(s):

Benoit P. Guillod ◽

Richard G. Jones ◽

Simon J. Dadson ◽

Gemma Coxon ◽

Gianbattista Bussi ◽

...

Keyword(s):

Time Series ◽

Sea Ice ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Climate Model ◽

Sea Surface ◽

Large Set ◽

Future Scenarios ◽

High Precipitation ◽

The Uk

Abstract. Hydro-meteorological extremes such as drought and heavy precipitation can have large impacts on society and the economy. With potentially increasing risks associated with such events due to climate change, properly assessing the associated impacts and uncertainties is critical for adequate adaptation. However, the application of risk-based approaches often requires large sets of extreme events, which are not commonly available. Here, we present such a large set of hydro-meteorological time series for recent past and future conditions for the United Kingdom based on weather@home2, a modelling framework consisting of a global climate model driven by observed or projected sea surface temperature and sea ice which is downscaled to 25 km over the European domain by a regional climate model. Sets of 100 time series are generated for each of (i) a historical baseline (1900–2006), (ii) five near future scenarios (2020–2049) and (ii) five far future scenarios (2070–2099). The five scenarios in each future time slice all follow the Representative Concentration Pathway 8.5 (RCP8.5) and sample the range of sea surface temperature and sea ice changes from CMIP5 models. Validation of the historical baseline highlights good performance for temperature and potential evaporation, but substantial seasonal biases in mean precipitation, which are corrected using a linear approach. For extremes in low precipitation over a long accumulation period (>3 months) and shorter duration high precipitation (1–30 days), the time series generally represents past statistics well. Future projections show small precipitation increases in winter but large decreases in summer on average, leading to an overall drying, consistently with the most recent UK climate projections (UKCP09) but larger in magnitude than the latter. Both drought and high precipitation events are projected to increase in frequency and intensity in most regions, highlighting the need for appropriate adaptation measures. Overall, the presented dataset is a useful tool for assessing the risk associated with drought and more generally with hydro-meteorological extremes in the UK.

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Human geographies of sea ice: freeze/thaw processes around Igloolik, Nunavut, Canada

Polar Record ◽

10.1017/s0032247407007152 ◽

2008 ◽

Vol 44 (2) ◽

pp. 127-153 ◽

Cited By ~ 37

Author(s):

Gita J. Laidler ◽

Theo Ikummaq

Keyword(s):

Sea Ice ◽

Regional Scale ◽

Open Water ◽

Current Strength ◽

Ice Formation ◽

Future Research ◽

Freeze Thaw ◽

Ice Conditions ◽

Inuit Knowledge ◽

Ocean Environment

ABSTRACTSea ice has been, and continues to be, an integral component of life in the Inuit community of Igloolik, Nunavut. Located on an island of the same name off the northeastern coast of Melville Peninsula, extensive ice formation occurs in Fury and Hecla Strait. This creates an important travel and hunting platform, and enables access to Baffin Island, the mainland, moving ice, hunting and fishing grounds, and nearby communities. With the combined importance, dynamism, and continuous use of this frozen ocean environment, local Inuit elders and hunters have developed a detailed and nuanced understanding of sea ice conditions, freeze/thaw processes, and the influences of winds and currents on ice conditions. Working collaboratively with the community of Igloolik since February 2004, we present the results of 24 semi-directed interviews and 4 sea ice trips to provide a baseline understanding of local freezing processes (near-shore, open water, sea ice thickening, landfast ice, tidal cracks, floe edge, and moving ice), melting processes (snow melt, water accumulation and drainage, and break-up), wind influences on sea ice (wind direction and strength affecting sea ice formation and movement), and, current influences on sea ice (tidal variations and current strength affecting sea ice formation, movement, and polynya size/location). Strong emphasis is placed on Inuktitut terminology and spatial delineations of localised ice conditions and features. Therefore, this paper provides insights into local scale ice conditions and dynamics around Igloolik that are not captured in regional scale studies of Foxe Basin and/or Fury and Hecla Strait. Results have the potential to inform future research efforts on local/regional sea ice monitoring, the relationship between Inuit knowledge, language, and the environment, and addressing community interests through targeted studies.

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Recent Arctic Ocean Surface Air Temperatures in Atmospheric Reanalyses and Numerical Simulations

Journal of Climate ◽

10.1175/jcli-d-19-0703.1 ◽

2020 ◽

Vol 33 (10) ◽

pp. 4347-4367

Author(s):

Allison B. Marquardt Collow ◽

Richard I. Cullather ◽

Michael G. Bosilovich

Keyword(s):

Time Series ◽

Sea Ice ◽

Arctic Ocean ◽

Ice Cover ◽

The Arctic ◽

Central Arctic Ocean ◽

Mean Values ◽

Weather Forecasts ◽

Air Temperatures ◽

Autumn And Winter

AbstractSurface air temperatures have recently increased more rapidly in the Arctic than elsewhere in the world, but large uncertainty remains in the time series and trend. Over the data-sparse sea ice zone, the retrospective assimilation of observations in numerical reanalyses has been thought to offer a possible, but challenging, avenue for adequately reproducing the historical time series. Focusing on the central Arctic Ocean, output is analyzed from 12 reanalyses with a specific consideration of two widely used products: the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), and the European Centre for Medium-Range Weather Forecasts interim reanalysis (ERA-Interim, hereafter ERA-I). Among the reanalyses considered, a trend of 0.9 K decade−1 is indicated but with an uncertainty of 6%, and a large spread in mean values. There is a partitioning among those reanalyses that use fractional sea ice cover and those that employ a threshold, which are colder in winter by an average of 2 K but agree more closely with in situ observations. For reanalyses using fractional sea ice cover, discrepancies in the ice fraction in autumn and winter explain most of the differences in air temperature values. A set of experiments using the MERRA-2 background model using MERRA-2 and ERA-I sea ice and sea surface temperature indicates significant effects of boundary condition differences on air temperatures, and a preferential warm bias inherent in the MERRA-2 model sea ice representation. Differences between experiments and reanalyses suggest the available observations apply a significant constraint on reanalysis mean temperatures.

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Multi-year particle fluxes in Kongsfjorden, Svalbard

10.5194/bg-2018-174 ◽

2018 ◽

Author(s):

Alessandra D'Angelo ◽

Federico Giglio ◽

Stefano Miserocchi ◽

Anna Sanchez-Vidal ◽

Stefano Aliani ◽

...

Keyword(s):

Time Series ◽

Sea Ice ◽

Ocean Circulation ◽

Progressive Increase ◽

Physical Parameters ◽

Air Temperatures ◽

Mass Fluxes ◽

Inorganic Matter ◽

Particulate Fluxes ◽

Over Time

Abstract. High latitude regions are warming faster than other areas due to reduction of snow cover, sea ice loss, changes in atmospheric and ocean circulation. The combination of these processes, collectively known as polar amplification, provides an extraordinary opportunity to document the ongoing thermal destabilisation of the terrestrial cryosphere and the release of land-derived material into the aquatic environment. This study presents a six-year time-series (2010–2016) of physical parameters and particles fluxes collected by an oceanographic mooring in Kongsfjorden (Spitsbergen, Svalbard). In recent decades, Kongsfjorden has been experiencing rapid loss of sea ice coverage and retreat of local glaciers as a result of the progressive increase of ocean and air temperatures. The overarching goal of this study was to continuous monitoring the inner fjord particle sinking and to understand to what extent the temporal evolution of particulate fluxes were linked to the progressive changes in both Atlantic and freshwater input. Our data show high peaks of settling particles during warm seasons, in terms of both organic and inorganic matter. The different sources of suspended particles were described as a mixing of glacier carbonate, glacier-silicoclastic and autochthonous marine input. The glacier releasing sediments into the fjord resulted to be the predominant source, while the sediment input by rivers was reduced at the mooring site. Our time-series showed that the seasonal sunlight exerted first-order control on the particulate fluxes in the inner fjord. The marine fraction peaked when the solar radiation was maxima in May–June while the land-derived fluxes exhibited a 1–2 months lag consistent with the maximum air temperature and glacier melting. The inter-annual time-weighted total mass fluxes varied two-order of magnitudes over time, with relatively higher values in 2011, 2013 and 2015. Our results suggest that the land-derived input will remarkably increase over time in a warming scenario. Further studies are therefore needed to understand the future response of the Kongsfjorden ecosystem alterations in respect to the enhanced release of glacier-derived material.

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Seasonal variations in the properties and structural composition of sea ice and snow cover in the Bellingshausen and Amundsen Seas, Antarctica

Journal of Glaciology ◽

10.3189/s0022143000002902 ◽

1997 ◽

Vol 43 (143) ◽

pp. 138-151 ◽

Cited By ~ 2

Author(s):

M. O. Jeffries ◽

K. Morris ◽

W.F. Weeks ◽

A. P. Worby

Keyword(s):

Sea Ice ◽

Isotopic Composition ◽

Snow Cover ◽

Sea Water ◽

Ice Cores ◽

Ice Cover ◽

Snow Accumulation ◽

Ice Formation ◽

Frazil Ice ◽

Core Sets

AbstractSixty-three ice cores were collected in the Bellingshausen and Amundsen Seas in August and September 1993 during a cruise of the R.V. Nathaniel B. Palmer. The structure and stable-isotopic composition (18O/16O) of the cores were investigated in order to understand the growth conditions and to identify the key growth processes, particularly the contribution of snow to sea-ice formation. The structure and isotopic composition of a set of 12 cores that was collected for the same purpose in the Bellingshausen Sea in March 1992 are reassessed. Frazil ice and congelation ice contribute 44% and 26%, respectively, to the composition of both the winter and summer ice-core sets, evidence that the relatively calm conditions that favour congelation-ice formation are neither as common nor as prolonged as the more turbulent conditions that favour frazil-ice growth and pancake-ice formation. Both frazil- and congelation-ice layers have an av erage thickness of 0.12 m in winter, evidence that congelation ice and pancake ice thicken primarily by dynamic processes. The thermodynamic development of the ice cover relies heavily on the formation of snow ice at the surface of floes after sea water has flooded the snow cover. Snow-ice layers have a mean thickness of 0.20 and 0.28 m in the winter and summer cores, respectively, and the contribution of snow ice to the winter (24%) and summer (16%) core sets exceeds most quantities that have been reported previously in other Antarctic pack-ice zones. The thickness and quantity of snow ice may be due to a combination of high snow-accumulation rates and snow loads, environmental conditions that favour a warm ice cover in which brine convection between the bottom and top of the ice introduces sea water to the snow/ice interface, and bottom melting losses being compensated by snow-ice formation. Layers of superimposed ice at the top of each of the summer cores make up 4.6% of the ice that was examined and they increase by a factor of 3 the quantity of snow entrained in the ice. The accumulation of superimposed ice is evidence that melting in the snow cover on Antarctic sea-ice floes ran reach an advanced stage and contribute a significant amount of snow to the total ice mass.

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Sea Ice Concentration Products over Polar Regions with Chinese FY3C/MWRI Data

Remote Sensing ◽

10.3390/rs13112174 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2174

Author(s):

Lijian Shi ◽

Sen Liu ◽

Yingni Shi ◽

Xue Ao ◽

Bin Zou ◽

...

Keyword(s):

Time Series ◽

Sea Ice ◽

Ocean Circulation ◽

The Arctic ◽

Retrieval Algorithm ◽

Atmospheric Effects ◽

Observation Data ◽

Long Time Series ◽

Ice Concentration ◽

Long Time

Polar sea ice affects atmospheric and ocean circulation and plays an important role in global climate change. Long time series sea ice concentrations (SIC) are an important parameter for climate research. This study presents an SIC retrieval algorithm based on brightness temperature (Tb) data from the FY3C Microwave Radiation Imager (MWRI) over the polar region. With the Tb data of Special Sensor Microwave Imager/Sounder (SSMIS) as a reference, monthly calibration models were established based on time–space matching and linear regression. After calibration, the correlation between the Tb of F17/SSMIS and FY3C/MWRI at different channels was improved. Then, SIC products over the Arctic and Antarctic in 2016–2019 were retrieved with the NASA team (NT) method. Atmospheric effects were reduced using two weather filters and a sea ice mask. A minimum ice concentration array used in the procedure reduced the land-to-ocean spillover effect. Compared with the SIC product of National Snow and Ice Data Center (NSIDC), the average relative difference of sea ice extent of the Arctic and Antarctic was found to be acceptable, with values of −0.27 ± 1.85 and 0.53 ± 1.50, respectively. To decrease the SIC error with fixed tie points (FTPs), the SIC was retrieved by the NT method with dynamic tie points (DTPs) based on the original Tb of FY3C/MWRI. The different SIC products were evaluated with ship observation data, synthetic aperture radar (SAR) sea ice cover products, and the Round Robin Data Package (RRDP). In comparison with the ship observation data, the SIC bias of FY3C with DTP is 4% and is much better than that of FY3C with FTP (9%). Evaluation results with SAR SIC data and closed ice data from RRDP show a similar trend between FY3C SIC with FTPs and FY3C SIC with DTPs. Using DTPs to present the Tb seasonal change of different types of sea ice improved the SIC accuracy, especially for the sea ice melting season. This study lays a foundation for the release of long time series operational SIC products with Chinese FY3 series satellites.

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