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SEARCH Vision and Core Hypotheses. Presentation SEARCH Open Science Meeting Seattle, Washington Tuesday, October 28, 2003. Jamie Morison Polar Science Center, University of Washington [email protected] SEARCH Motivation. “Axiom”

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search vision and core hypotheses
SEARCH Vision and Core Hypotheses


SEARCH Open Science Meeting

Seattle, Washington

Tuesday, October 28, 2003

Jamie Morison

Polar Science Center, University of Washington

[email protected]

search motivation
SEARCH Motivation


The Arctic has been characterized in recent decades by a complex of significant, interrelated, pan-Arctic changes (Unaami).

atmospheric pressure and ice changes
Atmospheric Pressure and Ice 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 (Parkinson et al.)
  • Ice thickness decreased 42% in last 30 years (Rothrock et al, 1999)
ocean salinity change
Ocean Salinity Change

Fresher Pacific-Derived Water

Frontal Shift

Saltier Atlantic-Derived Water

Salinity Increase

From Morison, et al., , 2000, , Arctic, 53, 4.

Comparing the 1993 SCICEX data with the EWG climatology, we see a salinity increase in the upper 200 m of the Makarov Basin, indicating a shift in front between Atlantic and Pacific waters.

marine ecosystem change in 1990s
Marine Ecosystem Change in 1990s
  • Bering Sea jellyfish increase
  • Bering Sea phytoplankton blooms
  • Brackish water sea-ice ecosystems
  • Whale migrations shifting with reduced ice extent
  • Barents Sea fisheries shifting north
terrestrial change increased runoff
Terrestrial Change - Increased Runoff

Over 64 years, discharge from the 6 largest Eurasian arctic rivers has increased 7% (128 km3/y or 0.004 Sv) [Petersen et al., Science 2002]

Peterson, Bruce J. , Robert M. Holmes, James W. McClelland, Charles J. Vörösmarty, Richard B. Lammers, Alexander I. Shiklomanov, Igor A. Shiklomanov, and Stefan Rahmstorf, Increasing River Discharge to the Arctic Ocean, Science, December 13; 298: 2171-2173.

terrestrial change thawing of frozen ground
Terrestrial Change - Thawing of Frozen Ground
  • Permafrost temperatures in the Russian Arctic and intermittent permafrost region of Alaska rising in the 90s.
  • Permafrost temperatures falling in eastern Canada.
  • Thermokarst formation - drainage changes

What’s Unaami you ask?

Check out the Unaami Web site :

and Jim’s Principal

Component analysis.

High values in PC-1 correlated variables occurin recent years

  • Highest 1/3
  • Middle 1/3
  • Lowest 1/3

Overland et al., Clim. Change, 2003

three types of arctic change 30 years of data
Three Types of Arctic Change (30 Years of Data)
  • PC-1: Regime-like – Arctic Oscillation/NAO 1989 Shift
  • PC-2: Interdecadal - High Arctic (P&J Index)
  • PC-3: Linear – Lower Arctic Land
search hypothesis 1
SEARCH Hypothesis 1

Unaami is related to a spin up of the atmospheric Polar Vortex (e.g., AO).

connection to the polar vortex
AO update: Decreased in mid 90s but on average still high
  • Increase in Polar Vortex
  • Increases open water
  • Decreases Albedo
  • Increases radiative heating & melt
  • Freshens upper Beaufort Sea
Connection to the Polar Vortex
  • 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 & Russian Arctic

  • Cyclonic Circulation
  • - Increases export of fresh water and sea ice
  • Decreases salinity and increases stratification of the sub-Arctic seas
  • Inhibits global ocean overturning

Rising AO means lowers SAP over the Arctic.

Thompson and Wallace, 1998)

does positive ao produce more cyclonic circulation
a) 1979 - 88Does positive AO produce more cyclonic circulation?

Shift in axis of front and surface current

b) 1989 - 96

b) - a)

More Cyclonic

- Gudkovich (1961)

- Proshutinsky and Johnson (1997)

- Zhang, Rothrock and Steele, 1998, Warming of the Arctic Ocean by a strengthened Atlantic inflow, GRL, 25, 1745-1748.

does high ao cause a frontal shift
Does high AO cause a frontal shift?

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

From: Furevik, Chapman Conference, 2002

search hypothesis 2
SEARCH Hypothesis 2

Unaami is a component of climate change.

spin up of the polar vortex as part of greenhouse warming response
AO observations

(Shindell et al., 1999)

EOF 1 in GHW simulation with stratosphere

AO Index

GHW Simulation

GHW Simulation

(Fyfe et al.,1999)

GHW Simulation

Control Simulation

Observed -

earlier and larger than simulated

Spin up of the Polar Vortex as part of greenhouse warming response
search hypothesis 3
SEARCH Hypothesis 3

Feedbacks among the ocean, the land, and the atmosphere are critical to Unaami.

(a) 1979 - 88 meanZhang

Simulated sea ice changes by Zhang et al. (2000) show shift in drift axis, increased drift speeds, increased lateral melt

These lead to reduced residence time, reduced average thickness in the basin, but

(b) 1989 - 96 mean

increased ice export from the Basin to the North Atlantic.

Ice Budget Differences in the Basin*

(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)


Affects Albedo

(c) = (b) - (a)

Affects Global THC

Zhang, Rothrock and Steele, 2000, , J. Clim., 13, 3099-3114.

entire system undergone freshening
Borrowing from Bob Dickson’s talk tomorrow:entire system undergone freshening

Unaami’s increased runoff, change in Pacific water circulation, and increased ice production may be manifest in a general freshening of the entire system of overflow and entrainment that ventilates the deep Atlantic.

Dickson et al 2002

the polar vortex responds to arctic change
The Polar Vortex Responds to Arctic Change

A simulated atmospheric response to a change in Labrador Sea ice cover from minimum to maximum produces a shift in NAOmodel of -0.7 Std.

Changes in ice cover feedback on hemispheric circulation of the atmosphere


snow in Seattle, temperature in Washington D.C., etc.



Simulated difference in long-term JFM 1000 hPa height (m) between max ice extent and minimum ice extent in the Labrador Sea

Kvamtso, Skeie, and Stephenson, 2003, accepted, Int. J.of Climatology

search hypothesis 4
SEARCH Hypothesis 4

The physical changes of Unaami have large impacts on the Arctic ecosystems and society.

human dimension of change
Human Dimension of Change
  • Ice extent, thickness, and duration are reduced, hurting transportation and subsistence
  • 43% decrease in sea ice thickness (Rothrock et al. (1999)
  • 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)
  • 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
can the search paradigm help deal with change
Can the SEARCH paradigm help deal with change?


Rigor et al. (2002) find a negative correlation between winter AO index and ice extent the following fall. This suggests that ….

Six month ice condition “outlooks” are possible!

can the search paradigm help deal with change1
Can the SEARCH paradigm help deal with change?


Griffith et al. (2002) find a negative correlation between winter AO index and growth of the Porcupine Caribou herd. This suggests …

We can and should account for natural climate variations in discussions wildlife management in general and of ANWR specifically.

to test these hypotheses and help society deal with change
To test these hypotheses and help society deal with change…

requires a program long-term, large-scale observations (including retrospective and paleo studies), analysis, and modeling —SEARCH.

ocean temperature changes
Ocean Temperature Changes

Atlantic Water

1.5° warmer

From Morison, et al., , 2000, , Arctic, 53, 4.

  • Comparing the 1993 SCICEX data with the EWG climatology, we see warm cores over ridges indicating a shoaling and 1.5° warming of the temperature maximum where the Atlantic Water inflow subducts to spread through the Eurasian basin.
conditions at the north pole
Conditions at the North Pole

Oden ‘91,

SCICEX, ’93-’99

NPEO 2000




EWG Climatology,

1950s, 60s, 70s, 80s

  • EWG: 0.5° AW core at 350 m & 31 o/oo surface salinity
  • 1990s: 1.5° AW core @ 250 m & 32.5 o/oo surface salinity
  • 2000-02: AW temp slightly less than 1995 max Surface salinity < 1990’s

2003: Atlantic Water slightly fresher

Variations in Global Temperature and their uncertainties,1861- April 2001(land air and sea surface temperature)

The context (i): during the past century, the global mean temperature has increased in two main episodes of warming

When we plot air temperature as a function of latitude and time, two things become clear: 1) the World is warmer. Including 2002, all ten of the warmest years since records began in 1861 have occurred since 1990; Jones and Moberg, 2003. 2) in the last two decades the distribution of warming has become global.

Courtesy Tom Delworth, GFDL

…and Karcher et al have pieced together the spread of warming around the boundary of the Arctic Ocean ……in

1980, 1984, 1987 & 1991,

from Karcher et al 2003.

… and its continued spread in

1993, 1995, 1996 & 1999,

from Karcher et al 2003.