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

morison@apl.washington.edu

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 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

Outline

Ice andAtmospheric 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 ChangesSalinity 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)

Mendeleyev R.

Makarov B.

Alaska

Greenland

Siberia

0

500

Canada B.

Alpha R.

400

4 3

300

2

200

1

100

0-1-2-3

90°E

ΔS

75°N90°W

80°N

85°N

3000 m

1000 m2000 m

Eurasian B.

Lomono

Frontal Line1993

0°

180°

Frontal LinePre-1993

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, 2000-2001

Pacific-derived surface waters moving east and appearing off Ellesmere Island

Front still shifted counterclockwise near Pole

0

200

400

3210

-1-2-3

Alpha R.

Eurasian B.

Canada B.

Makarov B.

Mendeleyev R.

90°E

85°N80°N

180°

0°

Canada

Greenland

90°W

Lomonosov R.

100

300

500

Hydro 2001 12

34

5

12

3

4 56

7

Hydro 2000

2000 Drift2001 Drift

ΔS

Fresher at Coast

Saltier Atlantic-derived

NPEO ’00 & ‘01 Hydrographic Surveys

Pacific-derived

Morison et al., 2002, EOS, in press.

Ecosystem Change

(from Brodeur et al., 1999)

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, http://www.native 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 overGreenland Seaallows warmerAtlantic Water inArctic 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

AO Index

1900 1920 1940 1960 1980 20001900 1920 1940 1960 1980 2000

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 180-560 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 180-560 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, 3099-3114.

-0.5

-1.00.0

2.01.0

Shift in drift axis, increase in drift speeds, increased lateral melt

a) 1979 - 88 mean

b) 1989 - 96

c) = b) - a)Reduced residence time, production and average thickness

Ice Budget Differences*(89 to 96) - (79 to 88)

Vert. Growth 0.0Lateral Melt - 0.6Export - 0.7Ice Production -1.3

* (1012 m3 yr-1)

Could ocean changes be due to greenhouse warming?

(Fyfe et al.,1999)

1950 2000 2050 2100

GHW Simulation

GHW Simulation

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 2000 -2002

Polar Vortex increased in strength ca 1989

However still higher than 1950-88

Relaxed toward climatology in mid 1990’s

1950 1960 1970 1980 1990 2000 2010-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

Year

NCEP Wintertime (NDJFMA) AO Index from 1950 - 2002 Minus Avg INdex 1950 - 1988

0.744

0.744 + 0.816

+ 0.577

0.744 - 0.82

- 0.577

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.

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

Observations Motivate SEARCH

SEARCH Organization

SEARCH InteragencyProgram Management

Committee

SEARCH Science SteeringCommittee

Responding toChange Panel

Understanding ChangePanel

Detecting ChangePanel

Draft (12/3/02)SEARCH Organization Chart

e.g., SEARCH Coordination Office

SEARCH Activitiy Area, Arctic System Reanalysis

WG

WG

CLIVARWorking Group

ACSYS/CliCLiason

WG

WG

WG

WG

Partnerships

e.g.

CLIVAR

ACSYS/CliC

WGLinkages and Global Coupling

Distributed Marine Observatories

Distributed Terrestrial Observatories

Large-scale Atmospheric Observation

Social and Economic Interaction

Defining and Quantifying Unaami

WGSocial Response

SEARCH Activity AreaLarge-scale Atmospheric Observations

Alaska

Canada

Greenland

RussiaArctic OceanBarrow

Svalbard

Tiksi

Alert

GCOS - GTOSEnhanced Weather Stations

Remote Sensing e.g., TOVS

SEARCH Activity AreaDistributed Marine Observatories

Alaska

Canada

Greenland

RussiaArctic Ocean

CliC Repeat SectionsNPEO SectionsJWACS SectionData Gap SectionOcean Pathway MooringCross-shelf Exchange MooringBasin MooringGateway Mooring

Automated Drifting Stations

IABP Buoys

SEARCH Activity AreaDistributed Terrestrial Observatories

Alaska

Canada

Greenland

RussiaArctic OceanBarrow

Svalbard

Tiksi

Alert

ITEX Field SitesBorehole Sites

IMMMPS* Intensive Site

Intermediate and Extensive Sites

*Integrated Multiscale Multivariable Monitoring And Process Study network*Circumarctic Environmental Observatories

CEON*

Optimal

Assimilation or

Filtering Method

Observations

Optimal

Estimates

Model

Output

Nudging

Arctic Subsystem

Model

(e.g. Ice-Ocean Model)

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)