scholarly journals Results from the implementation of the Elastic Viscous Plastic sea ice rheology in HadCM3

Ocean Science ◽  
2006 ◽  
Vol 2 (2) ◽  
pp. 201-211 ◽  
Author(s):  
W. M. Connolley ◽  
A. B. Keen ◽  
A. J. 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 enhancements 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 development. We then consider the interannual variability of the sea ice in the new model and demonstrate improvements over the HadCM3 simulation.

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.


1994 ◽  
Vol 32 (2) ◽  
pp. 449-467 ◽  
Author(s):  
David Pollard ◽  
Starley L. Thompson

1990 ◽  
Vol 14 ◽  
pp. 72-77 ◽  
Author(s):  
G.M. Flato ◽  
W.D. Hibler

Sea-ice motion and dynamic thickness build-up play an important role in the transfer of heat between the ocean and the atmosphere and so must be included in large-scale climate studies. A “cavitating-fluid” approximation allows these dynamic processes to be parameterized in a simple way by ignoring shear and tensile strength yet retaining compressive strength. A simple procedure for approximating a cavitating fluid is presented here and is compared to the more complete viscous-plastic sea-ice model by performing several three year simulations with daily varying and monthly average wind forcing. Although differences exist on a monthly basis, the two models compare favourably over a seasonal cycle, particularly when compared to a thermodynamics only model in which ice motion is ignored. The lack of shear strength in a cavitating-fluid approximation makes it less sensitive to smoothing of the wind fields (as demonstrated by the monthly average wind simulations); however it also changes the detailed circulation and thickness build-up patterns somewhat. Overall, the cavitating-fluid approximation shows considerable promise for including sea-ice dynamics in large-scale climate models, especially where averaged wind fields are employed.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2957 ◽  
Author(s):  
Steven H. Ferguson ◽  
Brent G. Young ◽  
David J. Yurkowski ◽  
Randi Anderson ◽  
Cornelia Willing ◽  
...  

To assess whether demographic declines of Arctic species at the southern limit of their range will be gradual or punctuated, we compared large-scale environmental patterns including sea ice dynamics to ringed seal (Pusa hispida) reproduction, body condition, recruitment, and stress in Hudson Bay from 2003 to 2013. Aerial surveys suggested a gradual decline in seal density from 1995 to 2013, with the lowest density occurring in 2013. Body condition decreased and stress (cortisol) increased over time in relation to longer open water periods. The 2010 open water period in Hudson Bay coincided with extremes in large-scale atmospheric patterns (North Atlantic Oscillation, Arctic Oscillation, El Nino-Southern Oscillation) resulting in the earliest spring breakup and the latest ice formation on record. The warming event was coincident with high stress level, low ovulation rate, low pregnancy rate, few pups in the Inuit harvest, and observations of sick seals. Results provide evidence of changes in the condition of Arctic marine mammals in relation to climate mediated sea ice dynamics. We conclude that although negative demographic responses of Hudson Bay seals are occurring gradually with diminishing sea ice, a recent episodic environmental event played a significant role in a punctuated population decline.


2016 ◽  
Author(s):  
Steven H Ferguson ◽  
Brent G Young ◽  
David J Yurkowski ◽  
Randi Anderson ◽  
Cornelia Willing ◽  
...  

To assess whether demographic declines of Arctic species at the southern limit of their range will be gradual or punctuated, we compared large-scale environmental patterns including sea ice dynamics to ringed seal (Pusa hispida ) reproduction, body condition, recruitment, and stress in Hudson Bay from 2003-2013. Aerial surveys suggested a gradual decline in seal density from 1995-2013, with the lowest density occurring in 2013. Body condition decreased and stress (cortisol) increased over time in relation to longer open waterperiods. The 2010 open water period in Hudson Bay coincided with extremes in large-scale atmospheric patterns (NAO, AO, ENSO) resulting in the earliest spring breakup and the latest ice formation on record. The warming event was coincident with the highest stress levels and the lowest recorded ovulation rate and low pregnancy rate, few pups in the Inuit harvest, and observations of sick seals. We conclude that although negative demographic responses of Hudson Bay seals are occurring gradually with diminishing sea ice, a recent episodic environmental event played a significant role in a punctuated population decline.


1990 ◽  
Vol 14 ◽  
pp. 72-77 ◽  
Author(s):  
G.M. Flato ◽  
W.D. Hibler

Sea-ice motion and dynamic thickness build-up play an important role in the transfer of heat between the ocean and the atmosphere and so must be included in large-scale climate studies. A “cavitating-fluid” approximation allows these dynamic processes to be parameterized in a simple way by ignoring shear and tensile strength yet retaining compressive strength. A simple procedure for approximating a cavitating fluid is presented here and is compared to the more complete viscous-plastic sea-ice model by performing several three year simulations with daily varying and monthly average wind forcing. Although differences exist on a monthly basis, the two models compare favourably over a seasonal cycle, particularly when compared to a thermodynamics only model in which ice motion is ignored. The lack of shear strength in a cavitating-fluid approximation makes it less sensitive to smoothing of the wind fields (as demonstrated by the monthly average wind simulations); however it also changes the detailed circulation and thickness build-up patterns somewhat. Overall, the cavitating-fluid approximation shows considerable promise for including sea-ice dynamics in large-scale climate models, especially where averaged wind fields are employed.


1995 ◽  
Vol 47 (3) ◽  
pp. 179-230 ◽  
Author(s):  
Eckhard Kleine ◽  
Sergey Sklyar

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