scholarly journals Climate affects food availability to planktivorous least auklets Aethia pusilla through physical processes in the southeastern Bering Sea

2012 ◽  
Vol 454 ◽  
pp. 207-220 ◽  
Author(s):  
I Dorresteijn ◽  
AS Kitaysky ◽  
C Barger ◽  
ZM Benowitz-Fredericks ◽  
GV Byrd ◽  
...  
Keyword(s):  
Food Availability ◽  
Bering Sea ◽  
Physical Processes ◽  
Aethia Pusilla

scholarly journals Role of physical processes in formation of spring phytoplankton bloom in the Bering Sea

Trudy VNIRO ◽  
2020 ◽  
Vol 181 ◽  
pp. 206-222
Author(s):  
K.K. Kivva ◽  
◽  
J.V. Selivanova ◽  
M.N. Pisareva ◽  
A.A. Sumkina ◽  
...  
Keyword(s):  
Bering Sea ◽  
Phytoplankton Bloom ◽  
Physical Processes ◽  
Spring Phytoplankton Bloom ◽  
Eastern Bering Sea ◽  
Ice Retreat ◽  
Shelf Region ◽  
Sea Ice Retreat ◽  
Bering Sea Shelf ◽  
The Bering Sea

The main part of the annual primary production in the Arctic and Subarctic zones of the World Ocean is formed during the spring phytoplankton bloom. The timing of the bloom depends on combination of physical factors. Oscillating control hypothesis, proposed in [Hunt et al., 2002] for the Eastern Bering Sea, describes annual peculiarities of ecosystem development related to conditions of the spring phytoplankton bloom. We review propositions of this hypothesis on the reasons of phytoplankton bloom and its connection with physical processes for four local regions of the Bering Sea shelf. The regions include western, northern and south-eastern parts of the shelf. The analysis is based on ocean color and microwave remotely sensed data as well as on atmospheric reanalysis. The results allow for hypothesis improvement. An early phytoplankton bloom may be present in the surface layer in April or May along the eastern Bering Sea shelf even in situations of early sea ice retreat (e. g. February-March) or absence of ice during winter. However, such combinations were not observed in the western Bering Sea shelf region. In 1998–2018, early ice retreat in the western shelf region was always accompanied by relatively late phytoplankton bloom. The temporal lag between sea ice retreat and phytoplankton bloom may be substantial in some years along the southernmost position of the ice edge. On the other hand, the spring bloom in the northern part of the shelf usually follows the ice retreat. In case of early ice retreat, the timing of the bloom is determined not only by wind conditions, but also by heat balance at the surface of the sea. The results are proposed to be used in further analysis of ecosystem dynamics of the western Bering Sea shelf.

Analysis and Prediction of Short-Term Ice Drift

1988 ◽  
Vol 110 (1) ◽  
pp. 94-100 ◽  
Author(s):  
M. G. McPhee
Keyword(s):  
Boundary Layer ◽  
Bering Sea ◽  
Similarity Theory ◽  
Physical Processes ◽  
Motion Modeling ◽  
Short Term ◽  
Complex Demodulation ◽  
Ice Drift ◽  
Boundary Layer Dynamics ◽  
The Bering Sea

Techniques for kinematic analysis and dynamic, “free-drift” ice modeling are described and applied to interpretation of ice-drift data from recent marginal ice zone (MIZ) experiments. Kinematic description is based on a complex demodulation algorithm that separates inertial and tidal components from lower frequency, “synoptic” drift. Complex demodulation produces the time series of phasors (complex numbers describing phase and amplitude of the oscillating components), useful for separating the physical processes active in the upper ocean/ice system. Free-drift ice motion modeling utilizes a similarity theory for planetary-boundary-layer dynamics that includes the effect of buoyancy, both from rapid melting at the ice/ocean interface, and/or from a pre-existing density gradient (pycnocline) within the boundary layer. Two examples are considered: one in which a band of ice in the Bering Sea drifted rapidly away from the rest of the pack when it encountered warm water at the ice edge; and a second in which drift in the Greenland Sea was apparently affected by both a shallow pycnocline and a period of rapid melt.

scholarly journals Foraging Radii and Energetics of Least Auklets (Aethia pusilla) Breeding on Three Bering Sea Islands

1995 ◽  
Vol 68 (4) ◽  
pp. 647-672 ◽  
Author(s):  
Bryan S. Obst ◽  
Robert W. Russell ◽  
George L. Hunt ◽  
Zoe A. Eppley ◽  
Nancy M. Harrison
Keyword(s):  
Bering Sea ◽  
Sea Islands ◽  
Aethia Pusilla

Monitoring planktivorous seabird populations: validating surface counts of crevice-nesting auklets using mark–resight techniques

2006 ◽  
Vol 84 (6) ◽  
pp. 846-854 ◽  
Author(s):  
Lisa M. Sheffield ◽  
Adrian E. Gall ◽  
Daniel D. Roby ◽  
David B. Irons ◽  
Katie M. Dugger
Keyword(s):  
Bering Sea ◽  
Abundant Species ◽  
Density Estimates ◽  
Maximum Surface ◽  
Average Maximum ◽  
Aethia Pusilla ◽  
Secondary Productivity ◽  
Term Monitoring ◽  
The Bering Sea

Least Auklets ( Aethia pusilla (Pallas, 1811)) are the most abundant species of seabird in the Bering Sea and offer a relatively efficient means of monitoring secondary productivity in the marine environment. Counting auklets on surface plots is the primary method used to track changes in numbers of these crevice-nesters, but counts can be highly variable and may not be representative of the number of nesting individuals. We compared average maximum counts of Least Auklets on surface plots with density estimates based on mark–resight data at a colony on St. Lawrence Island, Alaska, during 2001–2004. Estimates of breeding auklet abundance from mark–resight averaged 8 times greater than those from maximum surface counts. Our results also indicate that average maximum surface counts are poor indicators of breeding auklet abundance and do not vary consistently with auklet nesting density across the breeding colony. Estimates of Least Auklet abundance from mark–resight were sufficiently precise to meet management goals for tracking changes in seabird populations. We recommend establishing multiple permanent banding plots for mark–resight studies on colonies selected for intensive long-term monitoring. Mark–resight is more likely to detect biologically significant changes in size of auklet breeding colonies than traditional surface count techniques.

Models of Thermodynamic Properties of Prominences

1979 ◽  
Vol 44 ◽  
pp. 349-355
Author(s):  
R.W. Milkey
Keyword(s):  
Thermodynamic Properties ◽  
Mass Transport ◽  
Emission Spectrum ◽  
Thermodynamic Parameters ◽  
Working Group ◽  
Physical Processes ◽  
Theoretical Concepts ◽  
Group 3 ◽  
Observational Techniques

The focus of discussion in Working Group 3 was on the Thermodynamic Properties as determined spectroscopically, including the observational techniques and the theoretical modeling of physical processes responsible for the emission spectrum. Recent advances in observational techniques and theoretical concepts make this discussion particularly timely. It is wise to remember that the determination of thermodynamic parameters is not an end in itself and that these are interesting chiefly for what they can tell us about the energetics and mass transport in prominences.

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

Sign in / Sign up

Export Citation Format

Share Document