scholarly journals MEAN CLIMATIC PARAMETERS OF THE UPPER MIXED LAYER IN THE BERING SEA (LOWER BOUNDARY, TEMPERATURE, SALINITY) AND THEIR ANNUAL VARIABILITY

2019 ◽  
Vol 199 ◽  
pp. 214-230
Author(s):  
V. A. Luchin
Keyword(s):  
Distribution Pattern ◽  
Mixed Layer ◽  
Deep Water ◽  
Bering Sea ◽  
Mixed Layer Depth ◽  
Lower Boundary ◽  
Aleutian Islands ◽  
Eastern Bering Sea ◽  
Upper Mixed Layer ◽  
The Bering Sea

All available deep-water oceanographic data obtained in the Bering Sea in 1929–2019 are analyzed (101,425 oceanographic stations). Lower boundary of the upper mixed layer is determined from the vertical temperature profiles using the criterion of temperature deflection from SST (10 % for June-October and 0.2, 0.3, and 0.5 o С for November-May). The mixed layer is rather thin in June-September, its thickness is 10–20 m over the major part of the sea, and 30–40 m at the straits between central Aleutian Islands. In DecemberMarch, the mixed layer depth increases to 120–160 m in the northern deep-water sea and up to 180–200 m at the straits between central and eastern Aleutian Islands, though it is thinner in plumes of warm waters entering from the Pacific. At the continental shelf, the mixed layer can be traced to the depth of 20–40 m in the eastern Bering Sea and 60–80 m at Kamchatka in December-January and to 60–80 m in the eastern Bering Sea and 80–100 m at Kamchatka in February-March. The mixed layer temperature distribution is distinguished by two completely different seasonal patterns. The winter distribution pattern with the highest temperature in the areas adjacent to the Aleutian Straits is typical for November-June. The summer pattern with high temperature in the Karaginsky Bay, Bristol Bay, and Norton Sound and lower temperature near the Aleutian Straits is typical for July-October. On the contrary, the salinity distribution pattern is stable, with the highest salinity at the central and eastern Aleutian Straits and lower salinity in the coastal zone as the Anadyr Bay and Norton Sound influenced by the river runoff.

scholarly journals Observational Study on the Variability of Mixed Layer Depth in the Bering Sea and the Chukchi Sea in the Summer of 2019

2021 ◽  
Author(s):  
Xiaohui Jiao ◽  
Jicai Zhang ◽  
Chunyan Li
Keyword(s):  
Mixed Layer ◽  
Bering Sea ◽  
Chukchi Sea ◽  
Mixed Layer Depth ◽  
Difference Threshold ◽  
Threshold Method ◽  
Layer Depth ◽  
Central Transition ◽  
Bering Sea Shelf ◽  
The Bering Sea

Abstract. Based on the high-resolution CTD data from 58 stations in the Bering Sea and the Chukchi Sea in the summer of 2019, the mixed layer depth (MLD) was obtained according to the density difference threshold method. It was verified that the MLD could be estimated more accurately by using a criterion of 0.125 kg/m3 in this region. The MLD in the Bering Sea basin was larger than that in the Bering Sea shelf, and both of them were smaller than that in the Bering Sea slope. The MLD increased northward both in the Chukchi Sea shelf and the Chukchi Sea slope. The farther northward, the greater the difference between the MLD calculated from temperature (MLDt) and the MLD calculated from density (MLDd) was, and the more important the role of salinity was in determining the MLD. The larger MLD (refer to MLDd specifically) in the Bering Sea slope might be due to the enhancement of mixing caused by the Bering Slope Current (BSC) and eddies. The horizontal advection of the Bering Sea Anadyr Water and the Alaska Coastal Water in the Bering Sea shelf led to the shallower MLD in the central transition zone. The northward increase of the MLD in the Chukchi Sea might be related to the low-salinity seawater resulting from the melting of sea ice in summer. The spatial variation of MLD was more closely related to the surface momentum flux than the sea surface buoyancy flux, and the wave had little effect.

scholarly journals Absorption and fluorescence properties of the eastern Bering Sea in the summer with special reference to the influence of a Cold Pool

2013 ◽  
Vol 10 (12) ◽  
pp. 19109-19154
Author(s):  
E. J. D'Sa ◽  
J. I. Goes ◽  
H. Gomes ◽  
C. Mouw
Keyword(s):  
Mixed Layer ◽  
Bering Sea ◽  
Outer Shelf ◽  
Fluorescence Properties ◽  
Cold Pool ◽  
Surface Mixed Layer ◽  
Inner Shelf ◽  
Eastern Bering Sea ◽  
Shelf Slope ◽  
The Bering Sea

Abstract. The absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM) are reported for the inner shelf, slope waters and outer shelf regions of the eastern Bering Sea during the summer of 2008, when a warm, thermally stratified surface mixed layer lay over a Cold Pool (< 2 °C) that occupied the entire middle shelf. CDOM absorption at 355 nm (ag355) and its spectral slope (S) in conjunction with excitation emission matrix (EEM) fluorescence and parallel factor analysis (PARAFAC) revealed large variability in the characteristics of CDOM in different regions of the Bering Sea. PARAFAC analysis aided in the identification of three humic-like (components 1, 2 and 5) and two protein-like (a tyrosine-like component 3, and a tryptophan-like component 4) components. In the extensive shelf region, average absorption coefficients at 355 nm (ag355 m–1) and DOC concentrations (μM) were highest in the inner shelf (0.342 ± 0.11 m–1, 92.67 ± 14.60 μM) and lower in the middle (0.226 ± 0.05 m–1, 78.38 ± 10.64 μM) and outer (0.176 ± 0.05 m–1, 80.73 ± 18.11 μM) shelves, respectively. Mean spectral slopes S were elevated in the middle shelf (24.38 ± 2.25 μm–1) especially in the surface waters (26.87 ± 2.39 μm–1) indicating high rates of photodegradation in the highly stratified surface mixed layer, which intensified northwards in the northern middle shelf likely contributing to greater light penetration and to phytoplankton blooms at deeper depths. The fluorescent humic-like components 1, 2, and 5 were most elevated in the inner shelf most likely from riverine inputs. Measurements at depth in slope waters (> 250 m) revealed low values of ag355 (0.155 ± 0.03 m–1) and S (15.45 ± 1.78 μm–1) indicative of microbial degradation of CDOM in deep waters. DOC concentrations, however were not significantly different suggesting CDOM sources and sinks to be uncoupled from DOC. Along the productive "green belt" in the outer shelf/slope region, absorption and fluorescence properties indicated the presence of fresh and degraded autochthonous DOM. Near the Unimak Pass region of the Aleutian Islands, low DOC and ag355 (mean 66.99 ± 7.94 μM; 0.182 ± 0.05 m–1) and a high S (mean 25.95 ± 1.58 μm–1) suggested substantial photobleaching of the Alaska Coastal Waters, but high intensities of humic-like and protein-like fluorescence suggested sources of fluorescent DOM from coastal runoff and glacier melt waters during the summer. Although our data show that the CDOM photochemical environment of the Bering Sea is complex, our current information on its optical properties will aid in better understanding of the biogeochemical role of CDOM in carbon budgets in relation to the annual sea ice and phytoplankton dynamics, and to improved algorithms of ocean color remote sensing for this region.

Lycodapus (Pisces: Zoarcidae) of eastern Bering Sea and nearby Pacific Ocean, with three new species and a revised key to the species

1981 ◽  
Vol 59 (4) ◽  
pp. 667-678 ◽  
Author(s):  
Alex E. Peden ◽  
M. Eric Anderson
Keyword(s):  
New Species ◽  
Pacific Ocean ◽  
Bering Sea ◽  
Sea Of Okhotsk ◽  
Range Limit ◽  
The Sea Of Okhotsk ◽  
Eastern Bering Sea ◽  
Northern Range Limit ◽  
Three New Species ◽  
The Bering Sea

Lycodapus leptus n.sp., L. poecilus n.sp., and L. psarostomatus n.sp. are described from the eastern Bering Sea. A new key to all known species of Lycodapus is presented. In addition, L. fierasfer Gilbert, L. parviceps Gilbert, and L. derjugini Andriashev are recognized from the Bering Sea and L. microdon Schmidt is recognized from the Sea of Okhotsk. The northern range limit of Lycodapus dermatinus Gilbert is established from a sea mount off southeastern Alaska. A specimen of Lycodapus that cannot be identified to species represents the most southern record for the genus in Asiatic waters.

scholarly journals Modeling connectivity of walleye pollock in the Gulf of Alaska: Are there any linkages to the Bering Sea and Aleutian Islands?

2016 ◽  
Vol 132 ◽  
pp. 227-239 ◽  
Author(s):  
Carolina Parada ◽  
Sarah Hinckley ◽  
John Horne ◽  
Michael Mazur ◽  
Albert Hermann ◽  
...  
Keyword(s):  
Bering Sea ◽  
Gulf Of Alaska ◽  
Walleye Pollock ◽  
Aleutian Islands ◽  
The Bering Sea

Application of a sequential regime shift detection method to the Bering Sea ecosystem

2005 ◽  
Vol 62 (3) ◽  
pp. 328-332 ◽  
Author(s):  
Sergei Rodionov ◽  
James E. Overland
Keyword(s):  
Bering Sea ◽  
Regime Shift ◽  
Poor Performance ◽  
Regime Shifts ◽  
Test Analysis ◽  
Eastern Bering Sea ◽  
Time Signals ◽  
Shift Detection ◽  
Changes Over Time ◽  
The Bering Sea

Abstract A common problem of existing methods for regime shift detection is their poor performance at the ends of time-series. Consequently, shifts in environmental and biological indices are usually detected long after their actual appearance. A recently introduced method based on sequential t-test analysis of regime shifts (STARS) treats all incoming data in real time, signals the possibility of a regime shift as soon as possible, then monitors how perception of the magnitude of the shift changes over time. Results of a STARS application to the eastern Bering Sea ecosystem show how the 1989 and 1998 regime shifts manifest themselves in biotic and abiotic indices in comparison with the 1977 shift.

scholarly journals Age, growth, and maturity of the whitebrow skate, Bathyraja minispinosa, from the eastern Bering Sea

2011 ◽  
Vol 68 (7) ◽  
pp. 1426-1434 ◽  
Author(s):  
Shaara M. Ainsley ◽  
David A. Ebert ◽  
Gregor M. Cailliet
Keyword(s):  
Bering Sea ◽  
Growth Models ◽  
Gompertz Model ◽  
Parameter Estimates ◽  
Population Declines ◽  
Age At Maturity ◽  
Von Bertalanffy Model ◽  
Eastern Bering Sea ◽  
Best Fit ◽  
The Bering Sea

Abstract Ainsley, S. M., Ebert, D. A., and Cailliet, G. M. 2011. Age, growth, and maturity of the whitebrow skate, Bathyraja minispinosa, from the eastern Bering Sea. – ICES Journal of Marine Science, 68: 1426–1434. Skates are a common bycatch in groundfish fisheries in the Bering Sea; however, their life-history characteristics are not well known. The study is the first to investigate the age, growth, and age at maturity of Bathyraja minispinosa. Ages were estimated using sectioned vertebrae and several growth models were compared. The Gompertz model was the best fit and no significant differences were detected between sexes for any model. The maximum age estimated was 37 years, and parameter estimates generated from the three-parameter von Bertalanffy model were k = 0.02 year−1 and L∞ = 146.9 cm total length (TL). Males reached their size at 50% maturity larger than females (70.1 and 67.4 cm, respectively), but no significant differences in the estimated size or age at maturity were found. Whereas B. minispinosa is smaller than many skate species in the eastern Bering Sea, it has a considerably longer estimated lifespan, indicating that size may not be a reliable method of estimating the vulnerability of a rajid species to population declines in the eastern North Pacific.

Distribution and movements of white foxes in northern and western Alaska

1968 ◽  
Vol 46 (5) ◽  
pp. 849-854 ◽  
Author(s):  
David L. Chesemore
Keyword(s):  
Sea Ice ◽  
Bering Sea ◽  
Early Spring ◽  
Aleutian Islands ◽  
Late Winter ◽  
Seasonal Movements ◽  
Alaskan Arctic ◽  
Northern Alaska ◽  
The Bering Sea

White foxes occur on the tundra of northern and western Alaska and predominate on St. Lawrence, St. Matthew, Hall, and Diomede Islands in the Bering Sea. Few white foxes are found on the Pribilof and Aleutian Islands where blue foxes dominate the local fox population. On the Alaskan Arctic Slope, two seasonal movements, the first in the fall when foxes move seaward towards the coast and sea ice, and the second in late winter and early spring when they return inland to occupy summer den sites, occur. Although reported in other arctic areas, no definite records of fox migrations in northern Alaska exist. Distribution records for white foxes in Alaska are summarized.

Sign in / Sign up

Export Citation Format

Share Document