1. Sea Ice Exchange across the Canadian Arctic Archipelago from Microwave Satellites Sea Ice Exchange across the Canadian Arctic Archipelago from Microwave Satellites T. A. Agnew 1, J. Vandeweghe 2, and A. Lambe 2 1 Environment Canada, Toronto, Canada 2 Engineering Department, University of Toronto, Toronto, Canada

2. Microwave Satellite Data Advanced Microwave Scanning Radiometer (AMSR): 4-year period September 2002 to June 2006. RADARSAT: for the earlier period (1998-2002) by Ron Kwok From these satellites you can get sea-ice area flux, to obtain ice volume fluxes you need contemporaneous ice thickness which is almost never available, use proxy estimates of ice thickness from bore hole estimates in the region, ULS (submarine, moored sites) and general knowledge of ice types in the region. AMSR provides daily estimates of ice motion every 6 pixels (37.5 km) and ice concentration at resolution of 12 km. However there is no data for July and August because ice motions are unreliable due to atmospheric moisture (10-month average Sept - June) RADARSAT provides 3-day ice motions on a 5 km grid but only for northern parts of the Archipelago. Define a number of flux gates surrounding the Archipelago and calculate the sea ice area flux

3. Corvalis 2006 Sea ice export into the North Atlantic

4. Fluxgates surrounding the Archipelago } QEI-S } QEI-N

5. Corvalis 2006 Error in Daily Sea-ice Area Flux 1. Error in u i is 4.64 km/day, error in c i is 10%, error in c i u i is σ f = 4.74 km/day 2. For example, AG gate is L = 180 km, N s = 180 km/37.5 km = 5, error daily flux across the gate is σ T = σ f L/(N s ) ½ = 380 km 2. 3. Monthly error: σ m = σ T (N d ) ½ = 2100 km 2 /month Estimating Ice-area Flux across the Gate using AMSR 1. Obtain an independent ice motion estimate every 6 pixels (37.5 km ) which is interpolate to an estimate of ice motion u i at each 25 km intervals Δx along each fluxgate and similarly for concentration c i. 2. Daily Ice Area Flux = ∑ c i u i Δx SeparationObservations Mean Difference (km/day) SD of Difference (km/day) Mean Buoy Displacement (km/day) 1-day198-0.49*(5 %) 4.649.74 Sea Ice Motion Error Compare with Arctic Drifting Buoys

6. Corvalis 2006 Area Flux Error Estimate Gate Name Gate Symbol L (km) σ T (day) (km 2 ) σ (month) (km 2 ) σ (10-month) (km 2 ) Amundsen Gulf AG18038021006600 M’Clure Strait MS18038021006600 QEI South QEI-S~18038021006600 QEI North QEI-N13534018505840 Lancaster Sound LS7525013704330 Jones Sound JS4521011703690 Smith Sound SS4521011703690

7. Corvalis 2006 * Negative means export toward the Arctic Ocean **thickness from Melling (2002) Cumulative 10-month Area Fluxes (10 3 km 2 ) each year YearAGMSQEI-SQEI-NLSJSSS 2003-41-16339 45108 20042-15204 551311 2005-8-4291 4257 2006-8143810 511110 Average-14-5306 49 109 Estimated ice thickness (m) 133.4 ** 1.5 - 21.51 Average volume flux (km 3 ) -14-151002092159

8. Corvalis 2006 Average Monthly Area Flux for the Northern Gates Negative means transport toward Arctic Ocean

9. AO index and Atmospheric Circulation over the Arctic Ocean Curtesy of Ignatias Rigor

10. Corvalis 2006 Pressure Gradient-Area Flux Negative means transport toward Arctic Ocean Corr =.74 Corr =.77

11. Corvalis 2006 *Negative means export into the Arctic Ocean + Kwok (2005, 2006) **Melling (2002) RADARSAT and AMSR-E Comparison for Gates facing the Arctic Ocean Sensor\Gate AG (10 3 km 2 ) MS (10 3 km 2 ) QEI-S (10 3 km 2 ) QEI-N (10 3 km 2 ) NS (10 3 km 2 ) AMSR-E 2003-2006 (No July, Aug) - 14 * -5 * 306 RADARSAT + 1998-2002 - 85 * -20 * 6233 Estimated ice thickness (m) 1 to 1.533.4 ** 3 Avge. Volume (km 3 yr -1 ) -70-425312100

12. Corvalis 2006 * Positive means export into Baffin Bay **thickness from Melling (2002) Cumulative 10-month Area Fluxes (10 3 km 2 ) each year YearAGMSQEI-SQEI-NLSJSSS 2003 -41-16339 45108 2004 2-15204 551311 2005 -8-4291 4257 2006 -8143810 511110 Average -14-5306 49109 Estimated ice thickness (m) 12.53.4 ** 1.5 - 21.51 Average volume flux (km 3 ) -14-12.51002085159

13. Corvalis 2006 Average Monthly Area Flux for the Southern Gates Positive means transport toward Baffin Bay

14. Corvalis 2006 *Negative means net loss of sea ice Net Change in Ice Area for the CAA (Net = AG+MS+QEI –LS–JS) Month\Year 2003 (10 3 km 2) 2004 (10 3 km 2) 2005 (10 3 km 2) 2006 (10 3 km 2) Average (10 3 km 2) Sep 1017121614 Oct 3-7-4100 Nov -29-7-1910-11 Dec -23-24-7-40-24 Jan -2-14-95-5 Feb -10-18-9-13-12 Mar -7-12-5 Apr -242-5-8-9 May -2-801-2 Jun 710122113 10-month Average -71-58-30-9-42

15. Corvalis 2006 Monthly Ice Area Budget

16. Corvalis 2006 Monthly Sea Ice Volume Budget

17. Corvalis 2006 *Negative means net loss of sea ice Net Volume Advection (Net = AG+MS+QEI –LS–JS) Month\Year 2003 (10 3 km 2) 2004 (10 3 km 2) 2005 (10 3 km 2) 2006 (10 3 km 2) Average (10 3 km 2) Sep3348365243 Oct16-193287 Nov-44-18-2728-15 Dec-41-50-11-63-41 Jan11-30-2025-3 Feb-6-28-18 -17 Mar5-102-19-6 Apr-3613-10-13-11 May6-10894 Jun2135385236 10-month Average -34-70282-5

18. Corvalis 2006 Advection versus Melt/Growth 2003 2004 2005 2006 (growth – melt) (import–export)

19. Corvalis 2006 Amundsen Gulf and M’Clure Strait are net exporters of sea ice into the Arctic Ocean (fall and winter) and QEI north and south gates import ice from the Arctic Ocean. The monthly variability depends on large scale circulation (strength and location of the Beaufort Sea High). Combining both satellite results, there is net export of about 50 km 3 yr -1 into the Arctic Ocean and there is a export of 100 km 3 yr -1 into Baffin Bay. This ice is generated from within the Archipelago itself. The net ice advection each month is about 10% of the monthly change due to ice growth/melt. These fluxes are considerably less than the flux of sea ice through Fram Strait (~ 2800 km 3 yr -1 ). Conclusions

20. Corvalis 2006

21. Fluxgates across Baffin, Davis and Fram

22. Corvalis 2006 Note: Positive means flux southward or toward Baffin Bay ** Transport for 10-months of the year Cumulative 10-month area fluxes in 10 3 km 2 each year Year\Gate Baffin Bay Davis Strait Fram Strait Cornwallis Island Barrow Strait Lancaster Sound 2003707513596122645 2004641602699183355 2005508373657102142 2006724494573192951 Average 645 ± 11495 ± 7631 ± 715 ± 427 ± 449 ± 4 Estimated ice thickness (m) 1.5 3.5 Average volume flux (km 3 ) 9707402210 **

23. Corvalis 2006 Monthly Ice Area Flux Positive means transport south

24. Corvalis 2006 Pressure Gradient-Area Flux Negative means transport toward Arctic Ocean

25. Fluxgates across Cornwallis, Barrow and Lancaster

26. Corvalis 2006 Monthly Ice Area Flux Positive means transport south

27. Corvalis 2006 Note: Positive means flux southward or toward Baffin Bay ** Transport for 10-months of the year Cumulative 10-month area fluxes in 10 3 km 2 each year Year\Gate Baffin Bay Davis Strait Fram Strait Cornwallis Island Barrow Strait Lancaster Sound 2003707513596122645 2004641602699183355 2005508373657102142 2006724494573192951 Average 645 ± 11495 ± 7631 ± 715 ± 427 ± 449 ± 4 Estimated ice thickness (m) 1.5 3.5 Average volume flux (km 3 ) 9707402210 **

28. Corvalis 2006

29. Modeling Sea Ice Formation/Transport in Baffin Bay Model daily ice transport, ice production and salt re- distribution using sea ice cover from AMSR rather than estimating the surface energy budget and then melting or growing the ice thermodynamically. Previous days ice cover, advect it by the ice motion, compare with the next days ice cover, ice is grown/melted to make the advected ice field match the next days ice cover (Pedersen and Coon, 2004) We obtain each day from AMSR, sea ice concentration, sea ice type, sea ice thickness, sea ice motion Advect the sea ice using a trajectory method to reduce numerical diffusion problems

30. Corvalis 2006 Net Freezing 2003/04 2004/05 Bathymetry

31. Corvalis 2006 Monthly Net Freezing/melting

32. Corvalis 2006 Salt Redistribution 2003/04 2004/05

33. Corvalis 2006 * Negative means export toward the Arctic Ocean **Melling (2002) Cumulative 10-month Volume Flux in km 3 each year YearAGMSQEI-SQEI-NLSJSSS 2003 -41-401123079158 2004 2-376914972011 2005 -8-99937487 2006 -83413033901710 Average -14-131022085159

34. Microwave Satellites Penetrate most cloud and do not require solar illumination RADARSAT resolution of 150 m and repeat coverage is 3 days (1998-2002) RADARSAT relies on surface scattering so you cannot get a contemporaneous ice thickness directly, must rely on proxy estimates of ice thickness Advance Microwave Scanning Radiometer for EOS (AMSR-E) daily repeat coverage but resolution 6 to 12 km and no ice motion estimates in July and August (2003-2006) AMSR is multi-channel/polarization and so has some skill in estimating thickness of FYI Define a number of flux gates surrounding the Archipelago and calculate the sea ice area flux

35. Corvalis 2006 Monthly Net Ice Volume Flux and Melt/Growth

36. Corvalis 2006 Monthly Net Ice Area Flux and Melt/Growth

37. Corvalis 2006 AO Index