2012 Changing Ocean 506E/497E - Lecture 1 - Woodgate

What makes the Arctic “hot”? Local communities UN Environ subsistence Prog 1/3 total USA ?

Oil/Gas Exploration Decreasing Ice cover Links to Global (albedo, CO2, circulation, permafrost and CH4) Sept Sea Ice extent (Magenta = 1979-2000)

Northwest Passage - southern route open since 2007 - northern route open 2007, 2010, 2011

Northeast Passage Sept 2007 Sea-ice extent - open since 2008 (Pink=1979-2000 mean min) Source: NSIDC from: Arctic Report Card 2012 www.arctic.noaa.gov/reportcard

INFLOWS OUTFLOWS Through Fram Strait - Pacific, Atlantic and surface waters - deep (0 - 2600m)

Russia Russia - order 10 Sv 80N 80N - comparatively salty Barents Sea Barents Sea - warm

Fram Fram Strait Strait Greenland Sea Sea Bering Bering Strait Strait

Greenland Greenland Canadian Alaska Canadian Archipelago Atlantic Water through the Archipelago Pacific Water through the Fram Strait and the Barents Sea Through the Canadian Archipelago Bering Strait - deep (0 - 2600m) - Pacific and surface waters - shallow (0 - 50m) - order 10 Sv - All into Atlantic - shallow (0 – few hundred m) - order 1 Sv - comparatively salty (Some short term southward flow - order 1 Sv - comparatively fresh - warm - seasonally warm/cold through the Bering Strait) - comparatively fresh

1 2012 Changing 506E/497E - Lecture 1 - Woodgate

OTHER INPUTS/OUTPUTS – E-P, rivers Summary: Arctic Ocean

Russia Broad, Shallow Shelves INPUTS RIVERS (Russian and US) - order 3000 km3/yr freshwater Deep Basins

Evaporation-Precipitation (Bering Strait order Shallow entrance from - order 2000 km3/yr freshwater 2500 km3/yr) Barents Sea the Pacific From the Atlantic From the Medium and Deep Pacific Fram connections to the Strait Atlantic Russia 80N Barents Sea OUTPUTS: Bering To the Strait Atlantic Greenland Fram StraitGreenland Ice Export through the Fram Strait Sea Canadian Bering 3 You are About the size Strait - equivalent to order 2000 km /yr Archipelago freshwater here Greenland To the of the USA! Alaska Canadian Archipelago USA Atlantic Chart from IBCAO Serreze et al., 2006, JGR

ATLANTIC LAYER PACIFIC WATER - warm, salty - nutrient rich Russia Russia 80N - largest volume input 80N - source of heat and freshwater Barents Sea Barents Sea

Fram Fram Strait Greenland Strait Greenland Sea Sea Bering Bering Strait Strait (high nutrient waters) Greenland - multipleGreenland routes, switches with (waters above 0 deg C deeper than 200m) Alaska Canadian Alaska Canadian atmospheric forcing?? Archipelago- 2 branches (Fram Strait, Barents Sea) Archipelago - roughly 0-200m - roughly 200-800m - does not always follow topography, - follows slopes and ridges more driven by surface forcing - quite weak (strongest flows=eddies) - eddies may be significant part of flow - separates from slopes .. somehow - cools to freezing during transit - cools somewhat during transit - transit time “order a decade” - transit time “1 or more decades”

2 2012 Changing Arctic Ocean 506E/497E - Lecture 1 - Woodgate

Arctic Sea-Ice Sea Ice Motion (growth and melt)

Climatology The International Arctic Buoy Program (run from UW) Rigor, et al MINIMUM (September)

Satellites (SSM/I, AMSR), NASA and others MAXIMUM (February) Buoy set in ice, reports position, IABP movie air pressure and http://nsidc.org Rigor, Ortmeyer et al, UW temperature to satellite http://iabp.apl.washington.edu Photo D. Barton,1992

The Arctic Storm Tracks Limited penetration into Arctic except through North Atlantic due to fairly zonal steering and blocking by land masses

Location of tropospheric jet Polar jet and mid- streams troposphere pressure

courtsey of Maksym courtsey of Maksym, BAS

3 2012 Changing Arctic Ocean 506E/497E - Lecture 1 - Woodgate

MEAN 1979-1998 Arctic Surface Air Shorthand Beaufort High Pressure (i.e. – the Arctic Oscillation (AO)

Surface Wind) SEA LEVEL PRESSURE = MEAN + VARIABILITY

BUT ANY PARTICULAR DAY CAN Beaufort High LOOK VERY DIFFERENT, e.g. WHAT THE ARCTIC SEES

Covariance of Sea Level Pressure with AO index (hPa/30 years)

From D.Thompson, based on Thompson and Wallace 1998 Rigor et al., 2002

HIGH AO LOW AO

from National Geographic Magazine, March 2000

4 2012 Changing Arctic Ocean 506E/497E - Lecture 1 - Woodgate

Changes in Arctic Climate are related to A New Dipole pattern?? the Arctic Oscillation (AO) AO Index 1950-2012 Covariance of Sea Level Pressure (www.cpc.ncep.noaa.gov) with AO index (hPa/30 years)

Hi AO – small Beaufort Gyre strong Atlantic Influence Lo AO – large Beaufort Gyre weaker Atlantic Influence

In the Arctic Ocean, the AO explains - 52% of SLP variance, and - 36% of summer SLP variance From D.Thompson, based on Thompson and Wallace 1998 .. but .. http://www.arctic.noaa.gov/reportcard/atmosphere.html Courtesy of I.Rigor

Arctic Surface Air Arctic Ozone Temperature Loss 2011 (over land) Comparable to Antarctic loss Cause - cold, long-lasting vortex.

General warming trend 2009, 2010 colder

Arctic Report Card, Overland et al, 2011 Arctic Report Card, Bernhard et al, 2011

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