Recent Changes in the Arctic and the Study of Environmental Arctic Change (SEARCH)

1. Recent Changes in the Arctic and the Study of Environmental Arctic Change(SEARCH) Canadian Foundation for Climate and Atmospheric Science Workshop on Arctic Climate February 20-21, 2003 James Morison Polar Science Center Applied Physics Laboratory University of Washington Seattle, Washington USA morison@apl.washington.edu

2. Outline • The 1990s revealed Arctic change involving atmosphere, ocean, and land. • The Arctic change appears connected to changes in the atmospheric circulation of the Northern Hemisphere. • Ocean changes potentially affect global climate through: Changing albedo Weakening global thermohaline circulation • In 2000-2002 the atmosphere and Arctic Ocean were still in a changed state. • The change motivates a program of observations, analysis, modeling, and assessment: the Study of Environmental Arctic Change (SEARCH) http://psc.apl.washington.edu/search/index.html • SEARCH requires internationalization

3. Ice andAtmospheric Pressure Changes • Beaufort High decreased and shifted east in 1990s • Transpolar Drift of ice shifted axis counterclockwise producing a more cyclonic motion in 1990s • Ice extent decreased 3%/decade • Ice thickness decreased 42% in last 30 years (Rothrock et al, 1999) • Extent negatively correlated with Arctic Oscillation (Rigor et al., 2002)

4. Ocean ChangesSalinity Difference, Pargo ‘93 - Climatology Fresher Pacific-Derived Water Frontal Shift Saltier Atlantic-Derived Water Salinity Increase From Morison, J. H., K. Aagaard, and M. Steele, 2000, Recent Environmental Changes in the Arctic: A Review, Arctic, 53, 4. • Shift in front between Atlantic and Pacific waters • Salinity increase in the upper 200 m of the Makarov • Surface salinity decrease in Beaufort Sea (SHEBA)

5. Ocean Differences From Climatology, 2000-2001 NPEO ’00 & ‘01 Hydrographic Surveys Saltier Atlantic-derived Pacific-derived Fresher at Coast Morison et al., 2002, EOS, in press. • Front still shifted counterclockwise near Pole • Pacific-derived surface waters moving east and appearing off Ellesmere Island

6. Ecosystem Change • Massive Bering Sea phytoplankton blooms • Brackish water sea ice ecosystems in Beaufort Sea • Whale migrations shifting with reduced ice extent • Barents Sea fisheries shifting north • Small perturbation in physical mode can create nonlinear change in other parts of the system

7. Human Dimension of Change • Weather is more unpredictable affecting safety, food gathering, and transportation • Increases in cyclone activity north of 65°N since at least 1958 (Serreze et al., 2000) • Ice extent, thickness, and duration are reduced, hurting transportation and food gathering • 43% decrease in sea ice thickness (Rothrock et al. (1999) • Decreased ice extent & changes in storm patterns produce higher seas that accelerate coastal erosion • Enhanced cyclonic ocean circulation raises coastal sea level (Proshutinsky and Johnson, 1997) • Inland precipitation changes cause drying affecting food gathering • Increases in fire frequency in Alaska over the past 50 years (Oechel and Vourlitis, 1996) • Increase in the abundance of woody shrub species and slow northward movement of treeline have major impacts on winter snow accumulation and soil temperature (Sturm et al., 2001), • Changes in climate raises concern about native foods • From Alaska Native Science Commission and Institute of Social and Economic Research, Alaska Traditional Knowledge and Native Foods Database, http://www.native knowledge.org

8. Connection to Global Climate • Increase in Polar Vortex • - Weakens Beaufort High • Increases open water • Decreases Albedo • Increases radiative heating & melt • Freshens upper Beaufort Sea • Increase in Polar Vortex • - More cyclonic ocean circulation • Shift in front and Transpolar Drift • Russian shelf water to Beaufort • Warm air advection • increases SAT • warms permafrost Warm air over Greenland Sea allows warmer Atlantic Water in Arctic Ocean Low pressure spins up Polar Vortex, brings warm air to Greenland Sea and Russian Arctic Rising AO means lowers atmospheric pressure over the Arctic. • Cyclonic Circulation • - Increases export of fresh water • Increases stratification in Greenland and Labrador seas • Inhibits global ocean overturning Thompson and Wallace, 1998)

9. Does high AO cause a frontal shift? From: Furevik, Chapman Conference, 2002 1973 LOW AO Concentration of Atlantic Water tracer (%) averaged over depth of 180-560 m for repeated 1973 forcing (Maslowski et al, 2000) 1993 HIGH AO Concentration of Atlantic Water tracer (%) averaged over depth of 180-560 m for repeated 1993 forcing (Maslowski et al., 2000) Model Suggests: Yes

10. Simulated Sea Ice Thickness Changes a) 1979 - 88 mean Shift in drift axis, increase in drift speeds, increased lateral melt b) 1989 - 96 Ice Budget Differences* (89 to 96) - (79 to 88) Vert. Growth 0.0 Lateral Melt - 0.6 Export - 0.7 Ice Production -1.3 * (1012 m3 yr-1) Reduced residence time, production and average thickness c) = b) - a) Zhang, Rothrock and Steele, 2000, Recent changes in Arctic sea ice: the interplay between ice dynamics and thermodynamics, J. Clim., 13, 3099-3114.

11. Could ocean changes be due to greenhouse warming? Simulations suggest spin up of the Polar Vortex is part of greenhouse warming response. (Fyfe et al.,1999) GHW Simulation GHW Simulation AO Index GHW Simulation Control Simulation Observed - earlier and larger than simulated Yes, or changes may indicate what’s to come.

12. Update 2000 -2002 • Polar Vortex increased in strength ca 1989 • Relaxed toward climatology in mid 1990’s • However still higher than 1950-88

13. Climatological Ice Extent at End of August Ice Extent at End of August 2002 Note: Ice extent negatively correlated with AO (Rigor et al, 2002)

14. Observations Motivate SEARCH • The changes, the impacts they are having on northern communities, and the potential impacts on global climate warrant a long-term program of observations, analysis, and modeling to understand them. • 2001 - Science Plan available at http://psc.apl.washington.edu/search/index.html • SEARCH is being developed in the US as an interagency* program. • The focus of the SEARCH Interagency Working Group (IWG) has been on how to obtain funding. • 2002 - First major SEARCH funding through the NSF Freshwater Initiative. See http://psc.apl.washington.edu/search/index.html. • The focus of the SEARCH Science Steering Committee has been how to implement the science. • 2003 (15/1) Draft SEARCH Implementation Strategy available at http://psc.apl.washington.edu/search/index.html. • * NSF, NOAA, NASA, DOD, DOE, DOI

15. SEARCH Organization

16. SEARCH Activity Area Large-scale Atmospheric Observations

17. SEARCH Activity Area Distributed Marine Observatories

18. SEARCH Activity Area Distributed Terrestrial Observatories CEON* *Circumarctic Environmental Observatories

19. SEARCH ASR - Arctic System Reanalysis

20. Critical and Timely SEARCH Issue:International Participation - International membership on SSC and Panels - International SEARCH Working Groups (e.g., ASOF) - Affiliation with large international programs (e.g., IASC, IGBP, International CLIVAR) - SEARCH-IASC International Symposium in 2005

21. Examples of Existing and Potential Canadian Participation - Organization - Understanding - DQU, ASR and LGC - Archipelago through flow - ASOF and FWI DAO (e.g., CFS Alert) DTO (e.g., CEON sites) DMO (e.g., Alert and NPEO)