Thermodynamic and dynamic ice thickness contributions in the Canadian Arctic Archipelago in NEMO-LIM2 numerical simulations

Abstract

Abstract. Sea ice thickness evolution within the Canadian Arctic Archipelago (CAA) is of great interest to science, as well as local communities and their economy. In this study, based on the NEMO numerical framework including the LIM2 sea ice module, simulations at both 1/4 and 1/12 • horizontal resolution were conducted from 2002 to 2016. The model captures well the general spatial distribution of ice thickness in the CAA region, with very thick sea ice (∼ 4 m and thicker) in the northern CAA, thick sea ice (2.5 to 3 m) in the west-central Parry Channel and M'Clintock Channel, and thin (< 2 m) ice (in winter months) on the east side of CAA (e.g., eastern Parry Channel, Baffin Island coast) and in the channels in southern areas. Even though the configurations still have resolution limitations in resolving the exact observation sites, simulated ice thickness compares reasonably (seasonal cycle and amplitudes) with weekly Environment and Climate Change Canada (ECCC) New Ice Thickness Program data at first-year landfast ice sites except at the northern sites with high concentration of old ice. At 1/4 to 1/12 • scale, model resolution does not play a significant role in the sea ice simulation except to improve local dynamics because of better coastline representation. Sea ice growth is decomposed into thermodynamic and dynamic (including all non-thermodynamic processes in the model) contributions to study the ice thickness evolution. Relatively smaller thermodynamic contribution to ice growth between December and the following April is found in the thick and very thick ice regions, with larger contributions in the thin ice-covered region. No significant trend in winter maximum ice volume is found in the northern CAA and Baffin Bay while a decline (r 2 ≈ 0.6, p < 0.01) is simulated in Parry Channel region. The two main contributors (thermodynamic growth and lateral transport) have high interannual variabilities which largely balance each other, so that maximum ice volume can vary interannually by ±12 % in the northern CAA, ±15 % in Parry Channel, and ±9 % in Baffin Bay. Further quantitative evaluation is required.

Pacific Water Pathway in the Arctic Ocean and Beaufort Gyre in Two Simulations With Different Horizontal Resolutions

“…The small difference in the surface freshwater input is due to the similar ice formation/melting in the two simulations. Hu et al () previously found that model horizontal resolution at such scales only plays a small role in sea ice simulation.…”

The Aftermath of Petermann Glacier Calving Events (2008–2012): Ice Island Size Distributions and Meltwater Dispersal

“…The simulation is run from 2002 to 2016 using surface forcing from the Canadian Centre for Meteorological and Environmental Prediction's (Environment and Climate Change Canada) Global Deterministic Prediction System (GDPS) ReForcasts (CGRF) (Smith et al, ). Further details on the model setup, as well as evaluation in and around Baffin Bay, can be found in Hu et al () and Hughes et al ().…”

Impact of the Surface Stress on the Volume and Freshwater Transport Through the Canadian Arctic Archipelago From a High‐Resolution Numerical Simulation

“…At Nares Strait, the simulated sea ice thickness is about 2 m, which agrees the winter observations from 2002 to 2012 that the median daily ice draft is from 1.5 to 3 m (Ryan & Münchow, ). A more complete analysis of sea ice thickness changes and dynamic‐versus‐thermodynamic contributions can be found in another study based on the same numerical experiment by Hu et al ().…”

“…Therefore, the modeled sea ice velocity is usually higher compared to the real word. The ice bridge is not resolved either; however, the accumulation of ice in the narrow channel plays a similar but limited role to reduce the ice velocity (see Figure 4d in Hu et al, ). It explains why the transport overestimation at Nares Strait happens later than that at West Lancaster Sound in our simulation.…”