1. Nadja Steiner 1,2 & Jim Christian 1,2, Warren Lee 2, Tessa Sou 1 1 IOS, Fisheries and Ocean Canada 2 CCCma, Environment Canada, Victoria, BC We are acknowledging the members of the CanESM2 and CanRCM4 model development group at CCCma (Canada) and development groups of the MPI-ESM-LR (Germany), MIROC-ESM (Japan), IPSL- CM5A-LR (France), HadGEM2-ES (UK) and GFDL-ESM2M (USA) models. Modeling the high-latitude ocean ecosystem - Opportunities and constraints

2. ACCASP: Aquatic Climate Change Adaptation and Services Program (Arctic) Ocean Land Five regions: Beaufort Sea, Canadian Arctic Archipelago, Baffin Bay/Davis Strait, Hudson Bay, Mackenzie Basin Assess available observations with respect to recent (~10yr) and longer term (30-50yr) trends and evaluate available model projections on 10yr and 50yr time scales for variables describing or affecting aquatic marine ecosystems => provide input and support for impacts, vulnerabilities and opportunities (IVO) analysis. Risks for ecosystems, fisheries, endangered species, infrastructure, SAR, safe shipping

3. Tivy et al. 2009 TRENDS

4. Salinity Temperature (C)Ωaragonite 24 26 28 30 32 0.8 1 1.2 1.4 -2 -1 0 1 2 3 4 2008 2011 Surface properties in 2008 and 2011 Courtesy Bill Williams

5. Carina Data Base 1996-2005 Courtesy M. Yamamoto-Kawai

6. Projections: AR5 Earth System Models and Representative Concentration Scenarios (RCPs): 4.5 8.5 Moss et al. 2010 Historical: 1986-2005 RCPs: 2006-2025... 2066-2085 CanESM2.0 (Canada): AGCM - 128x64L61 (~ 2.8 o lat/lon)‏ OGCM - 256x192L40 (~ 1.41 o lon, 0.94 o lat) MPI-ESM-LR (Germany) MIROC-ESM (Japan) IPSL-CM5A-LR (France) HadGEM2-ES (UK) GFDL-ESM2M (USA)

7. PELAGIC Atmosphere BENTHOS CO 3 2- HCO 3 - H+H+ H 2 CO 3 H2OH2OCO 2 (aq) CO 2 Ocean Ocean floor Sea-Ice + CO 2 ↑ = H + ↑ = Acidification = pH ↓ = Ω ↓ PH = - log10(a H+ ) CaCO3 saturation state Ω = [Ca 2+ ][CO 3 2- ] / K for aragonite and calcite ( Ω calc > Ω arag ) CO 2 ? Mixing Mixing – turbulence

8. PH September - RCP8.5 – AR5 models 1986-2005 2066-2085 2006-2025 CanESM2 MPI (D) HadGEM2(UK) GFDL (US) IPSL (F) under- saturated

9. IPSL-CM5A-LR (F)GFDL-ESM (USA)MPI-ESM-LR (D) MIROC-ESM (J)HadGEM2-ES (UK)CanESM2 (Can) Simulated aragonite saturation state (surf) 2066-2085 – RCP8.5

10. RCP 8.5 Beaufort Sea Coutesy T. Sou

11. Maximum Mixed Layer Depth (March) 1986-2005 2066-2085 CanESM2 (Can)GFDL-ESM (USA) IPSL-CM5A-LR (F) MPI-ESM-LR (D)

12. Courtesy J. Christian Zonal Mean Aragonite Saturation Horizon (HadGEM2) Upper ocean Supersaturated CaCO3 stable Deep Ocean Undersaturated CaCO3 dissolves Upper ocean Supersaturated CaCO3 stable Deep Ocean Undersaturated CaCO3 dissolves CO 2

13. Courtesy J. Christian Zonal Mean Aragonite Saturation Horizon (HadGEM2)

14. CanESM2 HadGEM2 (UK) MIROC (J) MPI (D)IPSL (F) 500 1000 3000 2000 2500 1500 21002800 20202040 206021002800 20202040 2060 21002800 20202040 2060 500 1000 3000 2000 2500 1500 IPSL (F) MPI (D) Ω a - RCP8.5 – AR5 models GFDL (US) Central Beaufort Sea (224E, 77.5N) - Ω a RCP8.5 – AR5 models

15. University of Alberta North America Arctic (NAA) model (P. Myers): NEMO-LIM - so far projection runs for physical model only, based on HadGM – A2 (1 representation!) Plans: add ecosystem, Alk, DIC, O2, N2O, DMS, sea-ice (and benthic) ecosystem Projections on “Aquatic Basin Scale” New

16. Simulated Ice thickness (NAA model) March September

17. Coordinated Regional Downscaling Experiment (CORDEX) - Arctic domain 0.44 deg ~50 km ARCMIP 0.22 deg ~25km Earlier RCM efforts (NARCCAPP) do not fully cover the Arctic domain

18. Surface temperature increases throughout the Arctic region, with more warming over the ocean. Future warming is intensified in the Barents Sea, eastern Arctic Ocean, and to a lesser degree, in the Chukchi Sea. In all cases, the CAA and Beaufort Sea warms more than Baffin Bay. The RCP85 scenario temperature (not shown) has a similar pattern, with a faster rate of warming. Temperature CanRCM4 RCP4.5 Coutesy T. Sou

19. Constraints & Opportunities Limited observations (spatial and temporal coverage) Current model projections (ESMs) provide first assessment of e.g. Arctic ocean acidification. While providing a consistent picture (decrease in pH and Ω), they have insufficient resolution for regional applications. Regional downscaling limited to atmosphere: => Access to regional climate modelling efforts covering the Arctic (e.g. CORDEX) Potential for projections with aquatic basin scale models (forced by RCMs) – emphasis on multi-model comparisons Potential for management relevant model output for Arctic climate impacts - Links cause and effect...

20. Thanks..... Questions??? nadja.steiner@ec.gc.ca

21. Int. PP (June) CanESM2 (Can)MPI-ESM-LR (D)HadGEM2-ES (UK) 1986-2005 2066-2085

22. IPSL-CM5A-LR (F)GFDL-ESM (USA)MPI-ESM-LR (D) MIROC-ESM (J)HadGEM2-ES (UK)CanESM2 (Can) Simulated ice concentration September 2066-2085 – RCP8.5

23. AGCM CLASS Photosynthesis Anthropogenic CO 2 emissions Leaves Stem Roots Litter Soil Carbon CO 2 release CO 2 uptake Simple atmospheric chemistry CO 2 Prescribed fluxes of CH 4, N 2 O, etc The Canadian Earth System Model CanESM Atmosphere Ocean Land Sea-ice Carbon cycle

24. Denman et al. 2010 Aragonite saturation – pH relationship 0 o C and 32.5 ppt Solid circle: Alk=2230μmol/kg- characteristic of inflowing North Pacific surface water in the Canadian Basin (Yamamoto-Kawaii et al. 2009). Solid diamonds: successive dilution with freshwater to salinities from 32 to 24 with increments of 1 => additional reduction in saturation state 7.98 8.0