scholarly journals Variability of Circumpolar Deep Water transport onto the Amundsen Sea Continental shelf through a shelf break trough

2013 ◽  
Vol 118 (12) ◽  
pp. 6603-6620 ◽  
Author(s):  
K. M. Assmann ◽  
A. Jenkins ◽  
D. R. Shoosmith ◽  
D. P. Walker ◽  
S. S. Jacobs ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Water Transport ◽  
Deep Water ◽  
Shelf Break ◽  
Amundsen Sea ◽  
Circumpolar Deep Water

On the difficulty of modeling Circumpolar Deep Water intrusions onto the Amundsen Sea continental shelf

2014 ◽  
Vol 84 ◽  
pp. 26-34 ◽  
Author(s):  
Y. Nakayama ◽  
R. Timmermann ◽  
M. Schröder ◽  
H.H. Hellmer
Keyword(s):  
Continental Shelf ◽  
Deep Water ◽  
Amundsen Sea ◽  
Circumpolar Deep Water

scholarly journals Glacial Meltwater Identification in the Amundsen Sea

2017 ◽  
Vol 47 (4) ◽  
pp. 933-954 ◽  
Author(s):  
Louise C. Biddle ◽  
Karen J. Heywood ◽  
Jan Kaiser ◽  
Adrian Jenkins
Keyword(s):  
Dissolved Oxygen ◽  
Deep Water ◽  
Ocean Model ◽  
Water Type ◽  
Ice Shelf ◽  
Amundsen Sea ◽  
Glacial Meltwater ◽  
Circumpolar Deep Water ◽  
Water Characteristics ◽  
Multiparameter Analysis

AbstractPine Island Ice Shelf, in the Amundsen Sea, is losing mass because of warm ocean waters melting the ice from below. Tracing meltwater pathways from ice shelves is important for identifying the regions most affected by the increased input of this water type. Here, optimum multiparameter analysis is used to deduce glacial meltwater fractions from water mass characteristics (temperature, salinity, and dissolved oxygen concentrations), collected during a ship-based campaign in the eastern Amundsen Sea in February–March 2014. Using a one-dimensional ocean model, processes such as variability in the characteristics of the source water masses on shelf and biological productivity/respiration are shown to affect the calculated apparent meltwater fractions. These processes can result in a false meltwater signature, creating misleading apparent glacial meltwater pathways. An alternative glacial meltwater calculation is suggested, using a pseudo–Circumpolar Deep Water endpoint and using an artificial increase in uncertainty of the dissolved oxygen measurements. The pseudo–Circumpolar Deep Water characteristics are affected by the under ice shelf bathymetry. The glacial meltwater fractions reveal a pathway for 2014 meltwater leading to the west of Pine Island Ice Shelf, along the coastline.

scholarly journals Sensitivity of Circumpolar Deep Water Transport and Ice Shelf Basal Melt along the West Antarctic Peninsula to Changes in the Winds

2012 ◽  
Vol 25 (14) ◽  
pp. 4799-4816 ◽  
Author(s):  
Michael S. Dinniman ◽  
John M. Klinck ◽  
Eileen E. Hofmann
Keyword(s):  
Continental Shelf ◽  
Antarctic Peninsula ◽  
Deep Water ◽  
Constant Factor ◽  
Ice Shelf ◽  
The West ◽  
Ice Shelves ◽  
Circumpolar Deep Water ◽  
West Antarctic ◽  
West Antarctic Peninsula

Abstract Circumpolar Deep Water (CDW) can be found near the continental shelf break around most of Antarctica. Advection of this relatively warm water (up to 2°C) across the continental shelf to the base of floating ice shelves is thought to be a critical source of heat for basal melting in some locations. A high-resolution (4 km) regional ocean–sea ice–ice shelf model of the west Antarctic Peninsula (WAP) coastal ocean was used to examine the effects of changes in the winds on across-shelf CDW transport and ice shelf basal melt. Increases and decreases in the strength of the wind fields were simulated by scaling the present-day winds by a constant factor. Additional simulations considered effects of increased Antarctic Circumpolar Current (ACC) transport. Increased wind strength and ACC transport increased the amount of CDW transported onto the WAP continental shelf but did not necessarily increase CDW flux underneath the nearby ice shelves. The basal melt underneath some of the deeper ice shelves actually decreased with increased wind strength. Increased mixing over the WAP shelf due to stronger winds removed more heat from the deeper shelf waters than the additional heat gained from increased CDW volume transport. The simulation results suggest that the effect on the WAP ice shelves of the projected strengthening of the polar westerlies is not a simple matter of increased winds causing increased (or decreased) basal melt. A simple budget calculation indicated that iron associated with increased vertical mixing of CDW could significantly affect biological productivity of this region.

scholarly journals Variation in the Distribution and Properties of Circumpolar Deep Water in the Eastern Amundsen Sea, on Seasonal Timescales, Using Seal-Borne Tags

2018 ◽  
Vol 45 (10) ◽  
pp. 4982-4990 ◽  
Author(s):  
Helen K. W. Mallett ◽  
Lars Boehme ◽  
Mike Fedak ◽  
Karen J. Heywood ◽  
David P. Stevens ◽  
...  
Keyword(s):  
Deep Water ◽  
Amundsen Sea ◽  
Circumpolar Deep Water

scholarly journals Is Ekman pumping responsible for the seasonal variation of warm circumpolar deep water in the Amundsen Sea?

2017 ◽  
Vol 132 ◽  
pp. 38-48 ◽  
Author(s):  
T.W. Kim ◽  
H.K. Ha ◽  
A.K. Wåhlin ◽  
S.H. Lee ◽  
C.S. Kim ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Deep Water ◽  
Ekman Pumping ◽  
Amundsen Sea ◽  
Circumpolar Deep Water

scholarly journals Tropical forcing of Circumpolar Deep Water Inflow and outlet glacier thinning in the Amundsen Sea Embayment, West Antarctica

2012 ◽  
Vol 53 (60) ◽  
pp. 19-28 ◽  
Author(s):  
E.J. Steig ◽  
Q. Ding ◽  
D.S. Battisti ◽  
A. Jenkins
Keyword(s):  
Wind Stress ◽  
Deep Water ◽  
Reanalysis Data ◽  
Ocean Model ◽  
Tropical Pacific ◽  
Amundsen Sea ◽  
Outlet Glacier ◽  
Circumpolar Deep Water ◽  
Tropical Forcing ◽  
The North

AbstractOutlet glaciers draining the Antarctic ice sheet into the Amundsen Sea Embayment (ASE) have accelerated in recent decades, most likely as a result of increased melting of their ice-shelf termini by warm Circumpolar Deep Water (CDW). An ocean model forced with climate reanalysis data shows that, beginning in the early 1990s, an increase in westerly wind stress near the continental shelf edge drove an increase in CDW inflow onto the shelf. The change in local wind stress occurred predominantly in fall and early winter, associated with anomalous high sea-level pressure (SLP) to the north of the ASE and an increase in sea surface temperature (SST) in the central tropical Pacific. The SLP change is associated with geopotential height anomalies in the middle and upper troposphere, characteristic of a stationary Rossby wave response to tropical SST forcing, rather than with changes in the zonally symmetric circulation. Tropical Pacific warming similar to that of the 1990s occurred in the 1940s, and thus is a candidate for initiating the current period of ASE glacier retreat.

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