Coupled ocean/sea ice dynamics of the Antarctic Slope Current driven by topographic eddy suppression and sea ice momentum redistribution

2021 ◽  
Author(s):  
Yidongfang Si ◽  
Andrew Stewart ◽  
Ian Eisenman
1998 ◽  
Vol 27 ◽  
pp. 443-448 ◽  
Author(s):  
W. D. Hibler III ◽  
Petra Heil ◽  
Victoria I. Lytle

Due to frequent and intense storm systems moving across the Antarctic sea ice, ice drift and deformation fluctuate substantially. Observations of drilling buoys show inertial power to be a substantial component of ice drift and deformation. Because the inertial period at high latitudes is close to tidal periods, this peak can be amplified due to resonance. in practice, the energy dissipation by ice interaction plays a significant role in dampening out this inertial energy. in present sea-ice dynamics models both with and without ice interaction, this inertial motion is overdamped due to the underestimation of coupling to the ocean boundary layer. To develop a more consistent treatment of ice drift under fluctuating wind fields, we consider here a vertically integrated formulation of the ice-ocean boundary-layer system that incorporates a more realistic treatment of the upper ocean. Under steady wind conditions this model reduces to the normal water-drag formulation used in most sea-ice dynamics models. Simulations using this “imbedded” model are analyzed to elucidate the role of ice interaction in the Antarctic ice-pack in modifying the high-frequency motion and inducing deformation which in turn significantly impact ice-thickness characteristics. The simulations demonstrate that in an interacting ice field in the presence of kinematic waves inertial imbedding can lead to oscillations in ice concentration of up to ~10% open water. These variations are similar in magnitude to observed deformation fluctuations in tide-free regions.


2006 ◽  
Vol 3 (4) ◽  
pp. 777-803
Author(s):  
W. Connolley ◽  
A. Keen ◽  
A. McLaren

Abstract. We present results of an implementation of the Elastic Viscous Plastic (EVP) sea ice dynamics scheme into the Hadley Centre coupled ocean-atmosphere climate model HadCM3. Although the large-scale simulation of sea ice in HadCM3 is quite good with this model, the lack of a full dynamical model leads to errors in the detailed representation of sea ice and limits our confidence in its future predictions. We find that introducing the EVP scheme results in a worse initial simulation of the sea ice. This paper documents various improvements made to improve the simulation, resulting in a sea ice simulation that is better than the original HadCM3 scheme overall. Importantly, it is more physically based and provides a more solid foundation for future improvement. We then consider the interannual variability of the sea ice in the new model and demonstrate improvements over the HadCM3 simulation.


1991 ◽  
Vol 15 ◽  
pp. 9-16 ◽  
Author(s):  
Heinrich Hoeber

Observations of ice drift received from an array of ARGOS buoys drifting in the Weddell Sea in winter 1986 are described. Wind and current data are also available, permitting derivation of the complete momentum budget including the internal ice stress computed as residuum. It is shown that the variability of forcing both of the atmosphere and of the ocean is large, and that internal ice stress is not negligible; monthly vector averages amount to about half of the wind and water stresses. Coefficients of shear and bulk viscosity are derived according to Hibler's model of ice rheology; they turn out to be negative occasionally, in particular when small-scale forcing of the atmosphere is large.


2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Juan Pablo Corella ◽  
Niccolo Maffezzoli ◽  
Andrea Spolaor ◽  
Paul Vallelonga ◽  
Carlos A. Cuevas ◽  
...  

AbstractIodine has a significant impact on promoting the formation of new ultrafine aerosol particles and accelerating tropospheric ozone loss, thereby affecting radiative forcing and climate. Therefore, understanding the long-term natural evolution of iodine, and its coupling with climate variability, is key to adequately assess its effect on climate on centennial to millennial timescales. Here, using two Greenland ice cores (NEEM and RECAP), we report the Arctic iodine variability during the last 127,000 years. We find the highest and lowest iodine levels recorded during interglacial and glacial periods, respectively, modulated by ocean bioproductivity and sea ice dynamics. Our sub-decadal resolution measurements reveal that high frequency iodine emission variability occurred in pace with Dansgaard/Oeschger events, highlighting the rapid Arctic ocean-ice-atmosphere iodine exchange response to abrupt climate changes. Finally, we discuss if iodine levels during past warmer-than-present climate phases can serve as analogues of future scenarios under an expected ice-free Arctic Ocean. We argue that the combination of natural biogenic ocean iodine release (boosted by ongoing Arctic warming and sea ice retreat) and anthropogenic ozone-induced iodine emissions may lead to a near future scenario with the highest iodine levels of the last 127,000 years.


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