Barotropic Kelvin Wave‐Induced Bottom Boundary Layer Warming Along the West Antarctic Peninsula

2019 ◽  
Vol 124 (3) ◽  
pp. 1595-1615 ◽  
Author(s):  
D. J. Webb ◽  
R. M. Holmes ◽  
P. Spence ◽  
M. H. England
Keyword(s):  
Boundary Layer ◽  
Antarctic Peninsula ◽  
Bottom Boundary Layer ◽  
Kelvin Wave ◽  
The West ◽  
Bottom Boundary ◽  
West Antarctic ◽  
West Antarctic Peninsula ◽  
Wave Induced

scholarly journals Changes in the upper ocean mixed layer and phytoplankton productivity along the West Antarctic Peninsula

2018 ◽  
Vol 376 (2122) ◽  
pp. 20170173 ◽  
Author(s):  
Oscar Schofield ◽  
Michael Brown ◽  
Josh Kohut ◽  
Schuyler Nardelli ◽  
Grace Saba ◽  
...  
Keyword(s):  
Sea Ice ◽  
Antarctic Peninsula ◽  
Mixed Layer ◽  
Carbon Fixation ◽  
Upper Ocean ◽  
The West ◽  
Phytoplankton Productivity ◽  
West Antarctic ◽  
West Antarctic Peninsula

The West Antarctic Peninsula (WAP) has experienced significant change over the last 50 years. Using a 24 year spatial time series collected by the Palmer Long Term Ecological Research programme, we assessed long-term patterns in the sea ice, upper mixed layer depth (MLD) and phytoplankton productivity. The number of sea ice days steadily declined from the 1980s until a recent reversal that began in 2008. Results show regional differences between the northern and southern regions sampled during regional ship surveys conducted each austral summer. In the southern WAP, upper ocean MLD has shallowed by a factor of 2. Associated with the shallower mixed layer is enhanced phytoplankton carbon fixation. In the north, significant interannual variability resulted in the mixed layer showing no trended change over time and there was no significant increase in the phytoplankton productivity. Associated with the recent increases in sea ice there has been an increase in the photosynthetic efficiency (chlorophyll a -normalized carbon fixation) in the northern and southern regions of the WAP. We hypothesize the increase in sea ice results in increased micronutrient delivery to the continental shelf which in turn leads to enhanced photosynthetic performance. This article is part of the theme issue ‘The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change’.

scholarly journals Sedimentary Nutrient Supply in Productive Hot Spots off the West Antarctic Peninsula Revealed by Silicon Isotopes

2020 ◽  
Vol 34 (12) ◽  
Author(s):  
Lucie Cassarino ◽  
Katharine R. Hendry ◽  
Sian F. Henley ◽  
Ellen MacDonald ◽  
Sandra Arndt ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Hot Spots ◽  
Nutrient Supply ◽  
The West ◽  
Silicon Isotopes ◽  
West Antarctic ◽  
West Antarctic Peninsula

Water-mass properties and circulation on the west Antarctic Peninsula Continental Shelf in Austral Fall and Winter 2001

2004 ◽  
Vol 51 (17-19) ◽  
pp. 1925-1946 ◽  
Author(s):  
John M. Klinck ◽  
Eileen E. Hofmann ◽  
Robert C. Beardsley ◽  
Baris Salihoglu ◽  
Susan Howard
Keyword(s):  
Continental Shelf ◽  
Antarctic Peninsula ◽  
Water Mass ◽  
The West ◽  
West Antarctic ◽  
Mass Properties ◽  
West Antarctic Peninsula

Extreme Anomalous Atmospheric Circulation in the West Antarctic Peninsula Region in Austral Spring and Summer 2001/02, and Its Profound Impact on Sea Ice and Biota*

2006 ◽  
Vol 19 (15) ◽  
pp. 3544-3571 ◽  
Author(s):  
Robert A. Massom ◽  
Sharon E. Stammerjohn ◽  
Raymond C. Smith ◽  
Michael J. Pook ◽  
Richard A. Iannuzzi ◽  
...  
Keyword(s):  
Sea Ice ◽  
Antarctic Peninsula ◽  
Phytoplankton Bloom ◽  
Wide Field ◽  
The West ◽  
Austral Spring ◽  
Sea Ice Extent ◽  
Ice Dynamics ◽  
West Antarctic ◽  
West Antarctic Peninsula

Abstract Exceptional sea ice conditions occurred in the West Antarctic Peninsula (WAP) region from September 2001 to February 2002, resulting from a strongly positive atmospheric pressure anomaly in the South Atlantic coupled with strong negative anomalies in the Bellingshausen–Amundsen and southwest Weddell Seas. This created a strong and persistent north-northwesterly flow of mild and moist air across the WAP. In situ, satellite, and NCEP–NCAR Reanalysis (NNR) data are used to examine the profound and complex impact on regional sea ice, oceanography, and biota. Extensive sea ice melt, leading to an ocean mixed layer freshening and widespread ice surface flooding, snow–ice formation, and phytoplankton growth, coincided with extreme ice deformation and dynamic thickening. Sea ice dynamics were crucial to the development of an unusually early and rapid (short) retreat season (negative ice extent anomaly). Strong winds with a dominant northerly component created an unusually compact marginal ice zone and a major increase in ice thickness by deformation and over-rafting. This led to the atypical persistence of highly compact coastal ice through summer. Ecological effects were both positive and negative, the latter including an impact on the growth rate of larval Antarctic krill and the largest recorded between-season breeding population decrease and lowest reproductive success in a 30-yr Adélie penguin demographic time series. The unusual sea ice and snow cover conditions also contributed to the formation of a major phytoplankton bloom. Unexpectedly, the initial bloom occurred within compact sea ice and could not be detected in Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) ocean color data. This analysis demonstrates that sea ice extent alone is an inadequate descriptor of the regional sea ice state/conditions, from both a climatic and ecological perspective; further information is required on thickness and dynamics/deformation.

The experimental generation of double Kelvin waves

1971 ◽  
Vol 326 (1564) ◽  
pp. 39-52 ◽  
Keyword(s):  
Boundary Layer ◽  
Kelvin Waves ◽  
Bottom Boundary Layer ◽  
Maximum Frequency ◽  
Kelvin Wave ◽  
Bottom Slope ◽  
Shallow Water Theory ◽  
Constant Depth ◽  
Bottom Boundary ◽  
The Right

Experiments carried out with a rotating model basin confirm the existence of a type of slow oscillation (double Kelvin wave) predicted by linearized shallow-water theory. Such oscillations may occur in the neighbourhood of any zone where a bottom slope separates two regions of uniform depth. The energy is propagated along the contours of constant depth, with the shallower water always to the right of the direction of propagation (in the northern hemisphere). The theoretical dispersion relation is well verified, including the existence of a maximum frequency, and consequently a vanishing group-velocity, at a certain wavenumber. When the wavemaker is operated at a frequency greater than this maximum, steady currents are sometimes generated. The effects of curvature of the bottom contours are discussed, as well as the loss of energy by viscous dissipation in the bottom boundary-layer.

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