1. ECCO2 and Carbon Cycle Modeling : Arctic Ocean Applications Manfredi Manizza, EAPS-MIT

2. OUTLINE ? 1) Why the Arctic Carbon Cycle and ECCO2 ? 2) Where are we now ? 3) To do next 4) Open Discussion

3. 1 - Arctic Carbon Budget (NSF funded) TERRESTRIAL BIOSPHERE OCEAN (Physics/BGC) ATMOSPHERE Manizza, Follows, Marshall (MIT) Prinn (MIT) McGuire et al. (U. Alaska) CO2 Fluxes DOC Input

4. From Global to Regional with ECCO2 1) Global ECCO2 Solutions of Eddy-Resolving (1/4) MITgcm (Cube22 and more - Hill & Menemenlis). 2) Use of Arctic domain and extraction of physical fields (uvw,T,S,KPP,sea-ice cover,etc). 3) Set-up for OFF-LINE experiments on ACES Cluster @ MIT with MITgcm. 4) Implementation of ocean biogeochemical schemes of different complexity.

5. Global Cubed Sphere from ECCO2 Face 3

6. Focus on the Arctic Ocean (Face 3) 440 Grid Points 400 Grid Points 50 Vertical Levels Original Face 3 (510x510x50)

7. 2 - Tracer Release Experiment 1 : Out of Bering Strait 7 years – continuous ink source – instant monthly velocity fields Surface flow [Tracer] @ surface 0 10

8. 2 - Where are we now ? I) Set-up on MIT ACES cluster : DONE ! II) Testing Tracer Release/Sponge Layer : DONE ! III) Reaching Optimal Comput. Speed : ALMOST DONE.. IV) Experiments with decaying tracer : TO START V) Activation Full Ocean Carbon PKG : Long Term Goal.

9. 3 - Arctic Rivers & Ocean Carbon Cycle TERRESTRIAL BIOSPHERE OCEAN ATMOSPHERE Riverine Carbon Transfer CO2 Fluxes DOC Input

10. 3 -River-dominated semi-enclosed system Arctic Ocean = 10 % Global Ocean 1/2 Global Ocean Run-Off into the Arctic !!!!

11. Arctic Rivers & DOC Data from Bruce Peterson, MBL DOC Export gC/m2/yr

12. Assessing Lifetime of Riverine DOC Circulation Only Circul. + Decay ∂C/∂t = Adv. + Diff. ∂C/∂t = Adv. + Diff. + C  = 1/  = Decay Time Scale  = 1 month; 10 years ; 100 years C = Idealized Tracer

13. Tracer Release Experiment 2 : Lena River Mouth 6 years – continuous ink source – instant monthly velocity fields Surface flow [Tracer] @ surface 10 0

14. Arctic Project To-Do List 1) Reshaping NEW Arctic Domain (last minute) : COMMON ARCTIC GRID of ECCO2 (CAGE-2). 2) Use of latest version of ECCO2 (Cube 47) solutions including Freshwater Run-Off Dataset from P. Winsor. 3) Adaptation to CAGE-2 of DOC River Discharge Dataset from McClelland (UTexas) & Peterson (MBL).

15. THANKS to : Stephanie Dutkiewicz, Chris Hill, Jean-Michel Campin, Mick Follows, John Marshall, Dimitris Menemenlis, Peter Winsor, Bruce Peterson.