The Laptev Sea flaw lead—detailed investigation on ice formation and export during 1991/1992 winter season

Dethleff, Dirk; Loewe, Peter; Kleine, Eckhard

doi:10.1016/s0165-232x(98)00005-6

Cited by 80 publications

(108 citation statements)

References 9 publications

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“…The Laptev Sea was previously described as a key region to investigate climatic changes in the Arctic shelf seas (ACIA, 2005), as it is one of the major source areas for seaice export into the Transpolar Drift system (Dethleff et al, 1998). As can be seen in Fig.…”

Section: Regional Focus -Laptev Seamentioning

confidence: 99%

Circumpolar polynya regions and ice production in the Arctic: results from MODIS thermal infrared imagery from 2002/2003 to 2014/2015 with a regional focus on the Laptev Sea

et al. 2016

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Abstract. High-resolution MODIS thermal infrared satellite data are used to infer spatial and temporal characteristics of 17 prominent coastal polynya regions over the entire Arctic basin. Thin-ice thickness (TIT) distributions ( ≤ 20 cm) are calculated from MODIS ice-surface temperatures, combined with ECMWF ERA-Interim atmospheric reanalysis data in an energy balance model for 13 winter seasons (2002/2003to 2014/2015 November to March). From all available MODIS swath data, daily thin-ice thickness composites are computed in order to derive quantities such as polynya area and total thermodynamic (i.e., potential) ice production. A gap-filling approach is applied to account for cloud and data gaps in the MODIS composites. All polynya regions combined cover an average thin-ice area of 226.6 ± 36.1 × 10 3 km 2 in winter. This allows for an average total winter-accumulated ice production of about 1811 ± 293 km 3 , whereby the Kara Sea region, the North Water polynya (both 15 %), polynyas on the western side of Novaya Zemlya (20 %), as well as scattered smaller polynyas in the Canadian Arctic Archipelago (all combined 12 %) are the main contributors. Other wellknown sites of polynya formation (Laptev Sea, Chukchi Sea) show smaller contributions and range between 2 and 5 %. We notice distinct differences to earlier studies on pan-Arctic polynya characteristics, originating in some part from the use of high-resolution MODIS data, as the capability to resolve small-scale (> 2 km) polynyas and also large leads are increased. Despite the short record of 13 winter seasons, positive trends in ice production are detected for several regions of the eastern Arctic (most significantly in the Laptev Sea region with an increase of 6.8 km 3 yr −1 ) and the North Water polynya, while other polynyas in the western Arctic show a more pronounced variability with varying trends. We emphasize the role of the Laptev Sea polynyas as being a major influence on Transpolar Drift characteristics through a distinct relation between increasing ice production and ice area export. Overall, our study presents a spatially highly accurate characterization of circumpolar polynya dynamics and ice production, which should be valuable for future modeling efforts of atmosphere-ice-ocean interactions in the Arctic.

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Section: Regional Focus -Laptev Seamentioning

confidence: 99%

Circumpolar polynya regions and ice production in the Arctic: results from MODIS thermal infrared imagery from 2002/2003 to 2014/2015 with a regional focus on the Laptev Sea

et al. 2016

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“…It is assumed that a substantial part of the Fram Strait export is formed in the Siberian shelf seas, connected with Fram Strait via the Transpolar Drift. Among the Siberian shelf seas, the Laptev Sea is considered one of the most significant regions of net ice production and export (Zakharov, 1966a;Dethleff et al, 1998). It is very shallow, with water depths between 15 and 200 m (Timokhov, 1994), and comprises an area of approximately 500 × 10 3 km 2 .…”

Section: Introductionmentioning

confidence: 99%

Variability and trends in Laptev Sea ice outflow between 1992–2011

et al. 2013

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Abstract. Variability and trends in seasonal and interannual ice area export out of the Laptev Sea between 1992 and 2011 are investigated using satellite-based sea ice drift and concentration data. We found an average total winter (October to May) ice area transport across the northern and eastern Laptev Sea boundaries (NB and EB) of 3.48 × 10 5 km 2 . The average transport across the NB (2.87 × 10 5 km 2 ) is thereby higher than across the EB (0.61 × 10 5 km 2 ), with a less pronounced seasonal cycle. The total Laptev Sea ice area flux significantly increased over the last decades (0.85 × 10 5 km 2 decade −1 , p > 0.95), dominated by increasing export through the EB (0.55 × 10 5 km 2 decade −1 , p > 0.90), while the increase in export across the NB is smaller (0.3 × 10 5 km 2 decade −1 ) and statistically not significant. The strong coupling between across-boundary SLP gradient and ice drift velocity indicates that monthly variations in ice area flux are primarily controlled by changes in geostrophic wind velocities, although the Laptev Sea ice circulation shows no clear relationship with large-scale atmospheric indices. Also there is no evidence of increasing wind velocities that could explain the overall positive trends in ice export. The increased transport rates are rather the consequence of a changing ice cover such as thinning and/or a decrease in concentration. The use of a back-propagation method revealed that most of the ice that is incorporated into the Transpolar Drift is formed during freeze-up and originates from the central and western part of the Laptev Sea, while the exchange with the East Siberian Sea is dominated by ice coming from the central and southeastern Laptev Sea. Furthermore, our results imply that years of high ice export in late winter (February to May) have a thinning effect on the ice cover, which in turn preconditions the occurence of negative sea ice extent anomalies in summer.

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“…These polynyas are narrow, long bands of open water and/or thin ice, which separate landfast ice from seaward drifting ice on the Siberian continental shelves during winter (Dethleff et al, 1998), predominantly from October until June (Bareiss and Görgen, 2005). In general, the ice cover in the Laptev Sea can be divided into three regimes: fast ice, pack ice, and flaw polynyas in between .…”

Section: O Gutjahr Et Al: Quantification Of Ice Production In Laptementioning

confidence: 99%

“…Particularly in winter, sea water at the freezing point is directly exposed to a cold atmosphere, resulting in intense ice formation (Dethleff et al, 1998). Due to this strong surface heat loss within coastal polynyas frazil ice forms, which is subsequently transported toward the downwind edge of the polynyas (Smith et al, 1990;Morales Maqueda et al, 2004;Krumpen et al, 2011;Willmes et al, 2010).…”

Section: O Gutjahr Et Al: Quantification Of Ice Production In Laptementioning

confidence: 99%

“…It is one of the most significant regions where a considerable amount of the total Arctic sea ice is produced (Aagard et al, 1981;Dmitrenko et al, 2009;Dethleff et al, 1998;Willmes et al, 2011a;Tamura and Ohshima, 2011;Iwamoto et al, 2014). The newly formed sea ice is subsequently transported by the Transpolar Drift Stream and accounts for about 20 % of the total ice export through Fram Strait (Rigor and Colony, 1997).…”

Section: Introductionmentioning

confidence: 99%

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Quantification of ice production in Laptev Sea polynyas and its sensitivity to thin-ice parameterizations in a regional climate model

et al. 2016

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Abstract. The quantification of sea-ice production in the Laptev Sea polynyas is important for the Arctic sea-ice budget and the heat loss to the atmosphere. We estimated the ice production for the winter season 2007/2008 (NovemberApril) based on simulations with the regional climate model COSMO-CLM at a horizontal resolution of 5 km and compared it to remote sensing estimates. A reference and five sensitivity simulations were performed with different assumptions on grid-scale and subgrid-scale ice thickness considered within polynyas, using a tile approach for fractional sea ice. In addition, the impact of heat loss on the atmospheric boundary layer was investigated.About 29.1 km 3 of total winter ice production was estimated for the reference simulation, which varies by up to +124 % depending on the thin-ice assumptions. For the most realistic assumptions based on remote sensing of ice thickness the ice production increases by +39 %. The use of the tile approach enlarges the area and enhances the magnitude of the heat loss from polynyas up to +110 % if subgrid-scale open water is assumed and by +20 % for realistic assumptions. This enhanced heat loss causes in turn higher ice production rates and stronger impact on the atmospheric boundary layer structure over the polynyas. The study shows that ice production is highly sensitive to the thin-ice parameterizations for fractional sea-ice cover. In summary, realistic ice production estimates could be retrieved from our simulations. Neglecting subgrid-scale energy fluxes might considerably underestimate the ice production in coastal polynyas, such as in the Laptev Sea, with possible consequences on the Arctic sea-ice budget.

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The Laptev Sea flaw lead—detailed investigation on ice formation and export during 1991/1992 winter season

Cited by 80 publications

References 9 publications

Circumpolar polynya regions and ice production in the Arctic: results from MODIS thermal infrared imagery from 2002/2003 to 2014/2015 with a regional focus on the Laptev Sea

Circumpolar polynya regions and ice production in the Arctic: results from MODIS thermal infrared imagery from 2002/2003 to 2014/2015 with a regional focus on the Laptev Sea

Variability and trends in Laptev Sea ice outflow between 1992–2011

Quantification of ice production in Laptev Sea polynyas and its sensitivity to thin-ice parameterizations in a regional climate model

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