Stress‐based Finite Element Methods for Sea Ice Dynamics

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.

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Sea-ice dynamics in the Weddell Sea in winter

Annals of Glaciology ◽

10.3189/1991aog15-1-9-16 ◽

1991 ◽

Vol 15 ◽

pp. 9-16 ◽

Cited By ~ 1

Author(s):

Heinrich Hoeber

Keyword(s):

Sea Ice ◽

Bulk Viscosity ◽

Current Data ◽

Weddell Sea ◽

Small Scale ◽

Ice Dynamics ◽

Sea Ice Dynamics ◽

Momentum Budget ◽

Ice Drift

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.

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Climate changes modulated the history of Arctic iodine during the Last Glacial Cycle

Nature Communications ◽

10.1038/s41467-021-27642-5 ◽

2022 ◽

Vol 13 (1) ◽

Author(s):

Juan Pablo Corella ◽

Niccolo Maffezzoli ◽

Andrea Spolaor ◽

Paul Vallelonga ◽

Carlos A. Cuevas ◽

...

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Radiative Forcing ◽

Climate Changes ◽

Ice Cores ◽

The Arctic ◽

Glacial Cycle ◽

Ice Dynamics ◽

Sea Ice Dynamics ◽

Ultrafine Aerosol

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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