PERD CCIES POL: Current & Temperature Changes along the Newfoundland and Scotian Shelf/Slope

1. PERD CCIES POL:Current & Temperature Changes along the Newfoundland and Scotian Shelf/Slope Focus: Potential occurrence and impacts of climate changes in ocean currents, transports and temperatures in Atlantic offshore oil and gas production and exploration areas

2. Components: Observational studies of Labrador Current in key areas Regional ocean circulation models Implications of climate-change scenarios for regional circulation and impacts Participants: Loder, Hannah, Dupont, Geshelin, Yashayaev, Wright et al. (BIO, DFO) Han, Colbourne et al. (NAFC, DFO)

3. Linkages: Coordination with OEF POL (1.2.1) and industry co-sponsorships for moored measurements North Atlantic circulation modelling (BIO/Dalhousie) DFO Atlantic Zonal Monitoring Program (AZMP) NW Atlantic ocean climate studies (BIO et al.)

4. Current and Temperature Changes along the Newfoundland/Scotian Shelf/Slope PERD Climate Change Impacts on the Energy Sector (CCIES) POL 6.1.1 Coordination with PERD Offshore Environmental Factors POL 1.2.1 Oil and Gas Industry Partnerships in Observational Components

5. Oil & Gas Exploration and Production on the Scotian Shelf and Slope • Labrador Current extension along shelf edge • Proximity to energetic Gulf Stream

6. Oil & Gas Exploration and Production on the Grand Bank and in Flemish Pass • Severe ocean conditions • Iceberg alley (Labrador Current) along shelf edge • Persistent Labrador Current in deep-water frontier blocks

7. CCGV Hudson at Hibernia

8. Mean Transports in NW Atlantic • Shelf/Slope Labrador Current part of a larger-scale coastal current • Large diminution in transport in Grand Bank region • Past and potential future variations in equatorward extent of Labrador Current

9. Mean Transports in Grand Bank Region • Flow bifurcations north of Flemish Pass, at Tail of Bank, and in Laurentian Channel • Variability important to downstream regions

10. Freshwater Transports in NW Atlantic • Freshwater and ice from subarctic important to shelf/slope and deep-ocean dynamics in North Atlantic • Sea ice and icebergs important to transportation and oil and gas activities

11. Observational Program Elements 1 • Multi-Year Cross-Slope Arrays of Moorings at Key Sites on AZMP lines on: • Scotian Slope (Halifax line) • Newfoundland Slope (Flemish Pass line) • Current and hydrographic (T, S) time series • PERD OEF: high-frequency and extreme currents • Industry funding from 7 oil companies

12. Moored Array for Current & Hydrographic Observations on Scotian Slope • Current-meter moorings to describe variability in cross-slope structure over 2 years • Cooperative with PERD OEF and 7 oil companies

13. Variability in Seasonal Along-Slope Flow from 2000-02 Moored Measurements • SWward flow at all depths at 1100- and 2000-m sites until winter 2002 • NEward flow in upper 500m at all 3 sites in spring-summer 2002 • Seasonal + Interannual variability

14. Observational Program Elements 2 • Satellite Altimetric Data (1992- ) • Broad-scale surface current patterns & anomalies • Integration with other datasets • Potential for currents/transport monitoring ? • Historical Data • Currents: Moorings, Drifters • Hydrographic (1950- ): T, S, Geostrophic • Coastal Sea Level

15. Variability in Surface Currents from Satellite Altimetry (Han) • Averaged seasonal changes over 1992-2000 from TOPEX/Poseidon • Interannual variations also under investigation

16. Historical Current Stats in Flemish Pass • Means and standard deviations shown by season and depth • Limited coverage of seasonal variability and deep water • Mean (Labrador Current) generally exceeds fluctuations

17. PERD/Industry Current Meter Moorings in Flemish Pass: 2002-04Sites and Model Summer Currents • Site A (400m): Core of Labrador Current • Site B (1100m): Deep • Jun-Nov 2002: Recovered • Nov02 - Jul03: Deployed • Jul03 - Spr04: Proposed • Support from EnCana, ChevronTexaco & Petro-Canada

18. Seasonal-Mean Currents in 2002 • Climatological seasonal currents from model (contours) (Xu) • 2002 seasonal currents from moorings: summer, fall

19. Hydrography and Geostrophic Velocity in Flemish Pass: June 2002

20. Geostrophic Velocity + Bottom Velocity from Climatological Model: June 2002

21. Seasonal Surface Currents from Altimetry • Seasonal surface current anomalies from TOPEX/Poseidon (1992-2000), added to LA POP model mean flow • Persistent features of Labrador and North Atlantic Currents

22. Surface Current Variability from Altimetry • Time variability of currents at cross-over point of TOPEX / POSEIDON tracks • Plans to compare with geostrophic and moored measurements, and models

23. Regional Ocean Circulation Modelling • Evaluations of 1985-1998 Simulation from Los Alamos Ocean General Circulation Model (POP) (Smith et al.) • Realistic wind stress but restoration to T, S climatology at boundaries • High spatial (0.1o) resolution: quasi-realistic Gulf Stream and eddies • Volume, T and S budgets for Slope Water region • Comparisons of temporal variability with observations

24. Regional Ocean Circulation Modelling 2 • Evaluations of Hindcast Simulations with Dalhousie/BIO OGCM (modified POP) (planned with Wright et al.) • Realistic surface forcing and improved interior relaxation from climatology • Intermediate spatial (0.3o) resolution but plans to reduce • Focus on variability in Labrador Current extension and Slope Water

25. Regional Ocean Circulation Modelling 3 • Variability and Sensitivity Studies with Regional Model for Newfoundland Shelf (FEM) (planned with Han) • Input from larger-scale model for response to extreme wind forcing in 1990s

26. Implications of Climate-Change Scenarios • Implications for current, transport, hydrographic (and ice) variability on Newfoundland and Scotian Shelf/Slope • Labrador Current and Gulf Stream influences • Impacts on shelf-edge production facilities • Impacts on deeper-water (slope) developments • To Date • Literature review • Description and understanding of observed variability • Information transfers to industry

27. Implications of Climate-Change Scenarios • Refined strategy for 03/04 • Focus on identification of: forcing-response relations from climate variability studies and potential impacts of climate-change scenarios • Defer regional model simulations for climate change until improved larger-scale models • Prepare report on recent and potential oceanic changes relevant to climate-change impacts assessment for Atlantic oil and gas production areas

28. Summary Points • Moored measurement arrays, plus hydrographic sections and altimetry, providing improved estimates of Labrador Current variability (seasonal, interannual ?) at key sites • Mounting observational support for seasonality and interannual variability in Labrador Current extension beyond Grand Bank, but poorly understood • Improved capability for describing interaction of Labrador Current and Gulf Stream, but remains poorly understood

29. Summary Points 2 • Importance of variable atmospheric forcing, ice, freshwater and ocean dynamics • Reliable predictive model for seasonal and interannual variability of Labrador Current not yet available • Assessment of implications of climate change for Atlantic offshore can draw on knowledge of past variability while predictive capability being improved