Long-term variability in Arctic sea surface temperatures

Singh, Rajkumar Kamaljit; Maheshwari, Megha; Oza, Sandip R.; Kumar, Raj

doi:10.1016/j.polar.2013.10.003

Cited by 19 publications

(10 citation statements)

References 13 publications

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“…Temperature remained relatively constant in surface waters (Fig. ), which is in agreement with analyses of satellite‐retrieved SST trends for the Norwegian Sea during the first decade of the 21st century (Singh et al ). These patterns match the general hydroclimatic forcing for those years, as between the mid 1990s and the mid 2000s, the dominant phase of the NAO was negative (Fig.…”

Section: Discussionsupporting

confidence: 89%

Long‐term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects

Weidberg

Basedow

2019

Limnology & Oceanography

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Critical gaps in knowledge hinder our ability to infer spatiotemporal dynamics in pelagic ecosystems. In particular, environmental changes affecting key copepod species while overwintering in deep waters are still not well understood. Here, we analyzed an 11 yr time series (2000–2010) of winter (January/February) samplings in the Lofoten Basin to characterize the spatial distribution of Calanus finmarchicus overwintering abundances and to infer their long‐term temporal trends. The spatial structure of populations at depths between 700 and 900 m corresponded to mesoscale aggregations consistent with eddies in the region. Over time, increased abundances of copepods and of one of its main predators, the herring (Clupea harengus), matched a negative trend in the 7 yr lagged winter NAO index. However, this progressive climatic shift did not affect surface conditions in the region or southward but corresponded to an increase in salinity and a deepening of the vertical extension of the Atlantic Water layer. We hypothesized that this change in salinity structure across the water column increased the density contrast between copepods and ambient water masses and facilitates the ascent rates during seasonal vertical migration. We suggest a step‐wise mechanism from NAO large‐scale forcing to copepod and herring populations mediated by hydrographical changes in intermediate water masses to explain the observed trends in abundances. Thus, large‐scale, lagged climatic patterns affecting overwintering copepods might scale up to succesive trophic levels in the pelagic ecosystem.

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Section: Discussionsupporting

confidence: 89%

Long‐term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects

Weidberg

Basedow

2019

Limnology & Oceanography

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“…The data are available from 1982 until now, which is why the SST analysis starts in 1982. The OISST data set has been used in many climatological and modeling studies (e.g., De Szoeke and Xie, 2008;Artale et al, 2010;Singh et al, 2013;Banzon et al, 2016) due to its good temporal and spatial coverage. These are daily SST records (one daily value for each pixel), with spatial resolution of 0.25 Â 0.25 (approximately 25 km) based on the combination of two passive satellite data set, the Advanced Very High-Resolution Radiometer infrared satellite and Advanced Microwave Scanning Radiometer on the Earth Observing System, supplemented with SST observations from ships and buoys.…”

Section: Methodsmentioning

confidence: 99%

A baseline evaluation of oceanographic and sea ice conditions in the Hudson Bay Complex during 2016–2018

Lukovich

Jafarikhasragh

Tefs

et al. 2021

Elementa: Science of the Anthropocene

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In this paper, we examine sea surface temperatures (SSTs) and sea ice conditions in the Hudson Bay Complex as a baseline evaluation for the BaySys 2016–2018 field program time frame. Investigated in particular are spatiotemporal patterns in SST and sea ice state and dynamics, with rankings of the latter to highlight extreme conditions relative to the examined 1981–2010 climatology. Results from this study show that SSTs in northwestern Hudson Bay from May to July, 2016–2018, are high relative to the climatology for SST (1982–2010). SSTs are also warmer in 2016 and 2017 than in 2018 relative to their climatology. Similarly, unusually low sea ice cover existed from August to December of 2016 and July to September of 2017, while unusually high sea ice cover existed in January, February, and October of 2018. The ice-free season was approximately 20 days longer in 2016 than in 2018. Unusually high ice-drift speeds occurred in April of 2016 and 2017 and in May of 2018, coinciding with strong winds in 2016 and 2018 and following strong winds in March 2017. Strong meridional circulation was observed in spring of 2016 and winter of 2017, while weak meridional circulation existed in 2018. In a case study of an extreme event, a blizzard from 7 to 9 March 2017, evaluated using Lagrangian dispersion statistics, is shown to have suppressed sea ice deformation off the coast of Churchill. These results are relevant to describing and planning for possible future pathways and scenarios under continued climate change and river regulation.

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“…The trend in the January-April mean ice thickness in the Northeast Passage along the Russian coast was dominated by a decreasing trend. Considering the fact that sea surface temperature in the Northeast Passage experienced a cooling trend in the past 30 years [44], the gradual warming of surface air temperature should be responsible for the decreasing trend of landfast ice thickness. The change in the mean ice thickness in 9 of the 17 subregions was analyzed and illustrated in Figure 9.…”

Section: Landfast Ice Thicknessmentioning

confidence: 99%

Spatial and Temporal Variations in the Extent and Thickness of Arctic Landfast Ice

Zhao

et al. 2019

Remote Sensing

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Analyses of landfast ice in Arctic coastal areas provide a comprehensive understanding of the variations in Arctic sea ice and generate data for studies on the utilization of the Arctic passages. Based on our analysis, Arctic landfast ice mainly appears in January–June and is distributed within the narrow straits of the Canadian Archipelago (nearly 40%), the coastal areas of the East Siberian Sea, the Laptev Sea, and the Kara Sea. From 1976–2018, the landfast ice extent gradually decreased at an average rate of −1.1 ± 0.5 × 104 km2/yr (10.5% per decade), while the rate of decrease for entire Arctic sea ice was −6.0 ± 2.4 × 104 km2/yr (5.2% per decade). The annual maximum extent reached 2.3 × 106 km2 in the early 1980s, and by 2018, the maximum extent decreased by 0.6 × 106 km2, which is an area approximately equivalent the Laptev Sea. The mean duration of Arctic landfast ice is 44 weeks, which has gradually been reduced at a rate of −0.06 ± 0.03 weeks/yr. Regional landfast ice extent decreases in 16 of the 17 subregions except for the Bering Sea, making it the only subregion where both the extent and duration increases. The maximum mean landfast ice thickness appears in the northern Canadian Archipelago (>2.5 m), with the highest increasing trend (0.1 m/yr). In the Northeast Passage, the mean landfast ice thickness is 1.57 m, with a slight decreasing trend of −1.2 cm/yr, which is smaller than that for entire Arctic sea ice (−5.1 cm/yr). The smaller decreasing trend in the landfast ice extent and thickness suggests that the well-known Arctic sea ice decline largely occurred in the pack ice zone, while the larger relative extent loss indicates a faster ice free future in the landfast ice zone.

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Long-term variability in Arctic sea surface temperatures

Cited by 19 publications

References 13 publications

Long‐term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects

Long‐term variability in overwintering copepod populations in the Lofoten Basin: The role of the North Atlantic oscillation and trophic effects

A baseline evaluation of oceanographic and sea ice conditions in the Hudson Bay Complex during 2016–2018

Spatial and Temporal Variations in the Extent and Thickness of Arctic Landfast Ice

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