Survival of Arctic cod larvae (Boreogadus saida) in relation to sea ice and temperature in the Northeast Water Polynya (Greenland Sea)

2006 ◽  
Vol 63 (7) ◽  
pp. 1608-1616 ◽  
Author(s):  
Louis Fortier ◽  
Pascal Sirois ◽  
Josée Michaud ◽  
David Barber
Keyword(s):  
Sea Ice ◽  
Ice Cover ◽  
Sea Surface ◽  
Good Survival ◽  
Boreogadus Saida ◽  
Arctic Cod ◽  
First Feeding ◽  
Low Probability ◽  
Northeast Water Polynya ◽  
Evolutionary Persistence

We tested the hypothesis that the survival of Arctic cod larvae (Boreogadus saida) is limited at sea ice cover >50% and sea surface temperature (SST) <0 °C. In 1993 in the Northeast Water Polynya, a spring cohort (14 May – 15 June) was hatched under heavy ice cover (58%–91%) and cold SST (–1.7 to –1.0 °C) and a summer cohort (21 June – 21 July) under low ice cover (4%–31%) and above-zero SST (1.5 to 3.9 °C). Consistent with the hypothesis, the spring cohort had almost completely vanished by age 10 days (first feeding stage), while the summer cohort survived well and dominated the population by the end of our sampling in early August. By then, the few surviving spring larvae were on average 5.7 mm longer than summer larvae (18.6 vs. 12.9 mm). A retrospective analysis of ice cover in the polynya (1979 to 2003) indicated that first-feeding larvae of the spring cohort encountered good survival conditions (sea ice <50% and SST >0 °C) in only 12% of the years compared with 80% for the summer cohort. The survival advantage provided by a larger size at the onset of Arctic winter could explain the evolutionary persistence of a spring cohort despite the low probability of initial survival.

Palynological evidence of sea-surface conditions in the Barents Sea off northeast Svalbard during the postglacial period

2020 ◽  
pp. 1-15
Author(s):  
Camille Brice ◽  
Anne de Vernal ◽  
Elena Ivanova ◽  
Simon van Bellen ◽  
Nicolas Van Nieuwenhove
Keyword(s):  
Sea Ice ◽  
Surface Waters ◽  
Barents Sea ◽  
Ice Cover ◽  
Atlantic Water ◽  
Transitional Period ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Conditions ◽  
The Barents Sea

Abstract Postglacial changes in sea-surface conditions, including sea-ice cover, summer temperature, salinity, and productivity were reconstructed from the analyses of dinocyst assemblages in core S2528 collected in the northwestern Barents Sea. The results show glaciomarine-type conditions until about 11,300 ± 300 cal yr BP and limited influence of Atlantic water at the surface into the Barents Sea possibly due to the proximity of the Svalbard-Barents Sea ice sheet. This was followed by a transitional period generally characterized by cold conditions with dense sea-ice cover and low-salinity pulses likely related to episodic freshwater or meltwater discharge, which lasted until 8700 ± 700 cal yr BP. The onset of “interglacial” conditions in surface waters was marked by a major change in dinocyst assemblages, from dominant heterotrophic to dominant phototrophic taxa. Until 4100 ± 150 cal yr BP, however, sea-surface conditions remained cold, while sea-surface salinity and sea-ice cover recorded large amplitude variations. By ~4000 cal yr BP optimum sea-surface temperature of up to 4°C in summer and maximum salinity of ~34 psu suggest enhanced influence of Atlantic water, and productivity reached up to 150 gC/m2/yr. After 2200 ± 1300 cal yr BP, a distinct cooling trend accompanied by sea-ice spreading characterized surface waters. Hence, during the Holocene, with exception of an interval spanning about 4000 to 2000 cal yr BP, the northern Barents Sea experienced harsh environments, relatively low productivity, and unstable conditions probably unsuitable for human settlements.

scholarly journals Connection between Sea Surface Anomalies and Atmospheric Quasi-Stationary Waves

2020 ◽  
Vol 33 (1) ◽  
pp. 201-212
Author(s):  
G. Wolf ◽  
A. Czaja ◽  
D. J. Brayshaw ◽  
N. P. Klingaman
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Southern Oscillation ◽  
Late Summer ◽  
Ice Cover ◽  
Sea Surface ◽  
Late Winter ◽  
Driving Mechanism ◽  
The North ◽  
The North Atlantic

AbstractLarge-scale, quasi-stationary atmospheric waves (QSWs) are known to be strongly connected with extreme events and general weather conditions. Yet, despite their importance, there is still a lack of understanding about what drives variability in QSW. This study is a step toward this goal, and it identifies three statistically significant connections between QSWs and sea surface anomalies (temperature and ice cover) by applying a maximum covariance analysis technique to reanalysis data (1979–2015). The two most dominant connections are linked to El Niño–Southern Oscillation and the North Atlantic Oscillation. They confirm the expected relationship between QSWs and anomalous surface conditions in the tropical Pacific and the North Atlantic, but they cannot be used to infer a driving mechanism or predictability from the sea surface temperature or the sea ice cover to the QSW. The third connection, in contrast, occurs between late winter to early spring Atlantic sea ice concentrations and anomalous QSW patterns in the following late summer to early autumn. This new finding offers a pathway for possible long-term predictability of late summer QSW occurrence.

scholarly journals Melting of Perennial Sea Ice in the Beaufort Sea Enhanced Its Impacts on Early-Winter Haze Pollution in North China after the Mid-1990s

2020 ◽  
Vol 33 (12) ◽  
pp. 5061-5080 ◽  
Author(s):  
Yuyan Li ◽  
Zhicong Yin
Keyword(s):  
Sea Ice ◽  
North China ◽  
Beaufort Sea ◽  
Gulf Of Alaska ◽  
Ice Cover ◽  
Sea Surface ◽  
Haze Pollution ◽  
Sea Surface Temperature Anomalies ◽  
Haze Days ◽  
Perennial Ice

AbstractIn recent years, haze pollution has become the most concerning environmental issue in China due to its tremendous negative effects. In this study, we focus on the enhanced responses of December–January haze days in North China to September–October sea ice in the Beaufort Sea during 1998–2015. Via both observation and numerical approaches, compared with an earlier period (1980–97), the sea ice concentration in the Beaufort Sea presented large variability during 1998–2015. During 1980–97, the Beaufort Sea was mainly covered by perennial ice, and the ablation and freezing of sea ice mainly occurred at the south edge of the Beaufort Sea. Thus, heavy sea ice in autumn induced negative sea surface temperature anomalies across the Gulf of Alaska in November. However, the colder sea surface in the Gulf of Alaska only induced a weak influence on the haze-associated atmospheric circulations. In contrast, during 1998–2015, a drastic change in sea ice existed near the center of the Arctic Ocean, due to the massive melting of multiyear sea ice in the western Beaufort Sea. The perennial ice cover in the western Beaufort Sea was replaced by seasonal ice. The broader sea ice cover resulted in positive sea surface temperature anomalies in the following November. Then, suitable atmospheric backgrounds were induced for haze pollution in December and January. Simultaneously, the response of the number of haze days over North China to sea ice cover increased. These findings were verified by the CESM-LE simulations and aided in deepening the understanding of the cause of haze pollution.

Reconstruction of sea-surface temperature, salinity, and sea-ice cover in the northern North Atlantic during the last glacial maximum based on dinocyst assemblages

2000 ◽  
Vol 37 (5) ◽  
pp. 725-750 ◽  
Author(s):  
Anne de Vernal ◽  
Claude Hillaire-Marcel ◽  
Jean-Louis Turon ◽  
Jens Matthiessen
Keyword(s):  
Sea Ice ◽  
Surface Temperature ◽  
Last Glacial Maximum ◽  
North Atlantic ◽  
Ice Cover ◽  
Glacial Maximum ◽  
Sea Surface ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Past sea-surface conditions over the northern North Atlantic during the last glacial maximum were examined from the study of 61 deep-sea cores. The last glacial maximum time slice studied here corresponds to an interval between Heinrich layers H2 and H1, and spanning about 20-16 ka on a 14C time scale. Transfer functions based on dinocyst assemblages were used to reconstruct sea-surface temperature, salinity, and sea-ice cover. The results illustrate extensive sea-ice cover along the eastern Canadian margins and sea-ice spreading, only during winter, over most of the northern North Atlantic. On the whole, much colder winter prevailed, despite relatively mild conditions in August (10-15°C at most offshore sites), thus suggesting a larger seasonal contrast of temperatures than today. Lower salinity than at present is reconstructed, especially along the eastern Canadian and Scandinavian margins, likely because of meltwater supply from the surrounding ice sheets. These reconstructions contrast with those established by CLIMAP on the basis of planktonic foraminifera. These differences are discussed with reference to the stratigraphical frame of the last glacial maximum, which was not the coldest phase of the last glacial stage. The respective significance of dinocyst and foraminifer records is also examined in terms of the thermohaline characteristics of surface waters and the vertical structure of upper water masses, which was apparently much more stratified than at present in the northern North Atlantic, thus preventing deep-water formation.

scholarly journals Evaluation and climate sensitivity of the PlaSim v.17 Earth System Model coupled with ocean model components of different complexity

2020 ◽  
Author(s):  
Michela Angeloni ◽  
Elisa Palazzi ◽  
Jost von Hardenberg
Keyword(s):  
Sea Ice ◽  
Heat Transport ◽  
Mixed Layer ◽  
Climate Sensitivity ◽  
Ice Cover ◽  
Earth System Model ◽  
Sea Surface ◽  
System Model ◽  
Earth System ◽  
Feedback Mechanisms

Abstract. A set of experiments is performed with coupled atmosphere-ocean configurations of the Planet Simulator, an Earth-system Model of Intermediate Complexity (EMIC), in order to identify under which set of parameters the model output better agrees with observations and reanalyses of the present climate. Different model configurations are explored, in which the atmospheric module of PlaSim is coupled with two possible ocean models, either a simple mixed-layer (ML) ocean with a diffusive transport parameterization or a more complex dynamical Large-Scale Geostrophic (LSG) ocean, together with a sea-ice module. In order to achieve a more realistic representation of present-day climate, we performed a preliminary tuning of the oceanic horizontal diffusion coefficient for the ML ocean and of the vertical oceanic diffusion profile when using LSG. Model runs under present-day conditions are compared, in terms of surface air temperature, sea surface temperature, sea ice cover, precipitation, radiation fluxes, ocean circulation, with a reference climate from observations and reanalyses. Our results indicate that, in all configurations, coupled PlaSim configurations are able to reproduce the main characteristics of the climate system, with the exception of the Southern Ocean region in the PlaSim-LSG model, where surface air and sea surface temperatures are warm-biased and sea ice cover is by consequence highly underestimated. The resulting sets of tuned parameters are used to perform a series of model equilibrium climate sensitivity (ECS) experiments, with the aim to identify the main mechanisms contributing to differences between the different configurations and leading to elevated values of ECS. In fact, high resulting global ECS values are found, positioned in the upper range of CMIP5 and recent CMIP6 estimates. Our analysis shows that a significant contribution to ECS is given by the sea-ice feedback mechanisms and by details of the parameterization of meridional oceanic heat transport. In particular, the configurations using a diffusive heat transport in the mixed layer present an important sensitivity in terms of radiative forcing to changes in sea-ice cover, leading to an important contribution of sea-ice feedback mechanisms to ECS.

scholarly journals Atlantic Water advection vs glacier dynamics in northern Spitsbergen since early deglaciation

2017 ◽  
Author(s):  
Martin Bartels ◽  
Jürgen Titschack ◽  
Kirsten Fahl ◽  
Rüdiger Stein ◽  
Marit-Solveig Seidenkrantz ◽  
...  
Keyword(s):  
Sea Ice ◽  
Environmental Conditions ◽  
Late Holocene ◽  
Ice Cover ◽  
Atlantic Water ◽  
Sea Surface ◽  
Early Holocene ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Glacier Dynamics

Abstract. Atlantic Water (AW) advection plays an important role for climatic, oceanographic and environmental conditions in the eastern Arctic. Situated along the only deep connection between the Atlantic and the Arctic Ocean, the Svalbard Archipelago is an ideal location to reconstruct the past AW advection history and document its linkage with local glacier dynamics, as illustrated in the present study of a sedimentary record from Woodfjorden (northern Spitsbergen) spanning the last ~ 15 500 years. Sedimentological, micropalaeontological and geochemical analyses were used to reconstruct changes in marine environmental conditions, sea-ice cover and glacier activity. Data illustrate a partial breakup of the Svalbard–Barents–Sea Ice Sheet from Heinrich Stadial 1 onwards (until ~ 14.6 ka BP). During the Bølling-Allerød (~ 14.6–12.7 ka BP), AW penetrated as a bottom water mass into the fjord system and contributed significantly to the destabilisation of local glaciers. During the Younger Dryas (~ 12.7–11.7 ka BP), it intruded into intermediate waters while evidence for a glacier advance is lacking. A short-term deepening of the halocline occurred at the very end of this interval. During the early Holocene (~ 11.7–7.8 ka BP), mild conditions led to glacier retreat, a reduced sea-ice cover and increasing sea surface temperatures, with a brief interruption during the Preboreal Oscillation (~ 11.1–10.8 ka BP). During the late Holocene (~ 1.8–0.4 ka BP), a slightly reduced AW inflow and lower sea surface temperatures compared to the early Holocene are reconstructed. Glaciers, which previously retreated to the shallower inner parts of the Woodfjorden system, likely advanced during the late Holocene. In particular, as topographic control in concert with the reduced summer insolation partly decoupled glacier dynamics from AW advection during this recent interval.

scholarly journals A rapid transition from ice covered CO<sub>2</sub>–rich waters to a biologically mediated CO<sub>2</sub> sink in the eastern Weddell Gyre

2008 ◽  
Vol 5 (5) ◽  
pp. 1373-1386 ◽  
Author(s):  
D. C. E. Bakker ◽  
M. Hoppema ◽  
M. Schröder ◽  
W. Geibert ◽  
H. J. W. de Baar
Keyword(s):  
Surface Water ◽  
Sea Ice ◽  
Deep Water ◽  
Dissolved Inorganic Carbon ◽  
Ice Cover ◽  
Weddell Sea ◽  
Sea Surface ◽  
Upward Movement ◽  
Weddell Gyre ◽  
Warm Deep Water

Abstract. Circumpolar Deep Water (CDW), locally called Warm Deep Water (WDW), enters the Weddell Gyre in the southeast, roughly at 25° E to 30° E. In December 2002 and January 2003 we studied the effect of entrainment of WDW on the fugacity of carbon dioxide (fCO2) and dissolved inorganic carbon (DIC) in Weddell Sea surface waters. Ultimately the fCO2 difference across the sea surface drives air-sea fluxes of CO2. Deep CTD sections and surface transects of fCO2 were made along the Prime Meridian, a northwest-southeast section, and along 17° E to 23° E during cruise ANT XX/2 on FS Polarstern. Upward movement and entrainment of WDW into the winter mixed layer had significantly increased DIC and fCO2 below the sea ice along 0° W and 17° E to 23° E, notably in the southern Weddell Gyre. Nonetheless, the ice cover largely prevented outgassing of CO2 to the atmosphere. During and upon melting of the ice, biological activity rapidly reduced surface water fCO2 by up to 100 μatm, thus creating a sink for atmospheric CO2. Despite the tendency of the surfacing WDW to cause CO2 supersaturation, the Weddell Gyre may well be a CO2 sink on an annual basis due to this effective mechanism involving ice cover and ensuing biological fCO2 reduction. Dissolution of calcium carbonate (CaCO3) in melting sea ice may play a minor role in this rapid reduction of surface water fCO2.

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