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

 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 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)  SEARCH requires internationalization Outline

Ice and Atmospheric Pressure Changes  Ice thickness decreased 42% in last 30 years (Rothrock et al, 1999)  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  Extent negatively correlated with Arctic Oscillation (Rigor et al., 2002)

Ocean Changes Salinity Difference, Pargo ‘93 - Climatology  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) From Morison, J. H., K. Aagaard, and M. Steele, 2000, Recent Environmental Changes in the Arctic: A Review, Arctic, 53, 4. Saltier Atlantic-Derived Water Frontal Shift Salinity Increase Fresher Pacific-Derived Water

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

Ecosystem Change  Small perturbation in physical mode can create nonlinear change in other parts of the system  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

Human Dimension of Change  Ice extent, thickness, and duration are reduced, hurting transportation and food gathering  43% decrease in sea ice thickness (Rothrock et al. (1999)  From Alaska Native Science Commission and Institute of Social and Economic Research, Alaska Traditional Knowledge and Native Foods Database, knowledge.org  Changes in climate raises concern about native foods  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),  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)  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)

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

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

Simulated Sea Ice Thickness Changes Zhang, Rothrock and Steele, 2000, Recent changes in Arctic sea ice: the interplay between ice dynamics and thermodynamics, J. Clim., 13, Shift in drift axis, increase in drift speeds, increased lateral melt a) mean b) c) = b) - a) Reduced residence time, production and average thickness Ice Budget Differences* (89 to 96) - (79 to 88) Vert. Growth 0.0 Lateral Melt- 0.6 Export- 0.7 Ice Production-1.3 * (10 12 m 3 yr -1 )

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

Update  Polar Vortex increased in strength ca 1989  However still higher than  Relaxed toward climatology in mid 1990’s

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)

 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.  Science Plan available at  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.  First major SEARCH funding through the NSF Freshwater Initiative. See  The focus of the SEARCH Science Steering Committee has been how to implement the science.  2003 (15/1) Draft SEARCH Implementation Strategy available at  * NSF, NOAA, NASA, DOD, DOE, DOI Observations Motivate SEARCH

SEARCH Organization

SEARCH Activity Area Large-scale Atmospheric Observations

SEARCH Activity Area Distributed Marine Observatories

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

SEARCH ASR - Arctic System Reanalysis

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

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)