NOAA Arctic Ocean Observations for Climate

NOAA Arctic Research Office

John Calder, Kathy Crane

Arctic GOOS Activities

• 1. Arctic Sea Ice – Mass balance and dynamics -

• 2.Northern Bering Sea Changes

• 3. RUSALCA – Bering Strait Moorings

• 4. Labrador Sea – pilot project Arctic Fresh Water Contributions to the Atlantic Ocean

Pacific Gateway

GOAL 1 (Sea Ice Observations and Predictions)

1. Sea Ice Mass Balance andDynamics

• International Arctic Buoy Program

• Ice Mass Balance Buoys

• IMBs colocated with NSF- and Japan- sponsored ocean buoys

International Arctic Buoy Programme (IABP)Monitoring the Arctic Since 1979

Sea Ice Mass Balance Buoys

• Augment traditional International Arctic Buoy Program buoys (IABP) with new data – sea ice thickness and temperature, snow cover depth, under-ice ocean temperature (maybe radiation in future)

• GOAL: Attribute changes in ice thickness to ocean or atmosphere; compute heat flux; validation points for satellite measurements

Sea Ice Summary(I. Rigor)

• Wind driven changes in ice motion may be more important than variations in surface temperature.

• Many of the changes in arctic climate and sea ice are related to the Arctic Oscillation, which affects sea ice on many different time scales, and the ice “remembers” these affects for many years.

• This “memory” may be useful for forecasting sea ice conditions.

• What is the role of the ocean in forcing these changes? Increased flow of warm water from the Atlantic and Pacific have been reported, can this contribute to the decline of sea ice? Or is this heat trapped below the cold halocline layer?

• Have we passed the “tipping point”? Will ice-albedo feed back be the demise of arctic sea ice, or will prolonged low AO conditions restore thicker ice conditions?

• With the decline of Arctic sea ice, have there been fundamental changes in the physical processes? Are we in a different “sea ice” regime?

2. 3. The Bering and Chukchi Seas, Alaska and Chukotka

show amplified responses to climate change.

The United States and the Russian Federation are working together to monitor the change in flux into and out of the Arctic through the Bering Strait-the Pacific Gateway to the Arctic.

BERING SEA

PACIFICGATEWAY

ATLANTICGATEWAY

Northern Bering Sea

• Bering Strait region shallow (<50 m); a sensitive indicator of climate change

• Bering Sea shifting towards an earlier

spring

•Surface sea temperature increase in the

1990s vs the 1980s, tied to the Arctic

Oscillation further to the north (Stabeno

and Overland 2001)

• Freshening in Bering Strait since 2000

(Woodgate)

• Time series benthic studies indicate changes in both carbon deposition and benthic biomass since the late 1980’s (Grebmeier)

Bering Sea M2 Mooring - Temperature Record

Courtesy P. Stabeno

• Vertically Averaged Temp = + 2 oC after 2000

Woodgate and Aagaard, GRL 2005

• freshening of seawater passing through Bering Strait since 2002 (above)

• shelf-basin transport via advection, eddy formation, canyon transport LOTS OF

•UNKNOWNS

??

Increased Fresh Increased Fresh WaterWater

Flow From theFlow From theArctic to the NorthArctic to the North

AtlanticAtlantic

What are the What are the pathways of pathways of

fresh water flow fresh water flow across the across the

Pacific Pacific Gateway ?Gateway ?

??

FreshWater Fluxes-pathways

Circulation Superimposed on the Distribution of Benthic Biomass: 1970-1990

Alaska

Russia

Bering Sea

Chukchi Sea

Beaufort SeaEast Siberian Sea

Biomass g m-2

[Dunton, Goodall, Schonberg, Grebmeier, and Maidment, 2005, DSR accepted]

??

2. Russian-American Long-term Census of the Arctic: RUSALCA:

RUSALCA GOALS:

1. Take Observations Where Arctic Sea Ice Reduction is a Maximum

2. Monitor Fresh Water and Nutrient Fluxes and Transport Pathways Through the Pacific Gateway.

3. Monitor Ecosystem Indicators of Climate Change.

4. Improve Russian-U.S. Arctic Climate Science Relations

Actual RUSALCA Stations, 2004

Others…

Monitor Ecosystem Changes -Arctic Census ofMarine Life

ECOSYSTEM INDICATORS OF CLIMATE CHANGE

HeraldShelfValley

RusalcaAug 04

RUSSIAN-AMERICANMOORING LOCATIONS

2003 Sign Memorandum of Understanding, 2003 Sign Memorandum of Understanding, Russian Academy and NOAARussian Academy and NOAA

2004 2004 Khromov expeditionKhromov expedition Bering-Chukchi Seas

•Census of Marine Life and exploration of the Census of Marine Life and exploration of the Chukchi SeaChukchi Sea

•Monitoring current fluxes through the Bering Monitoring current fluxes through the Bering Strait and Herald CanyonStrait and Herald Canyon

•Methane explorationMethane exploration

2005, 2006 retrieval of mooring data2005, 2006 retrieval of mooring data

Fall 2005, PI Synthesis MeetingFall 2005, PI Synthesis Meeting

2007, 2008 2007, 2008 International Polar YearInternational Polar Year

RUSALCATIME LINE

20042004

200320032005

2005

20022002

NOAA Pacific ArcticGateway exploration

Arctic Research Office Expeditions

2007-2007-20082008

IBCAO Map

IPY07/08 International Pan-Arctic study regions

ASOF

RUSALCA

4. The Labrador Sea and Davis Strait, key sites involved in the global overturning

circulation

Observations need to resolve the small scales of key currents and water masses in the northern Atlantic and to track them through annual cycles and strong decadal variability. During the winters of 2003-04 and 2004-05, four Seagliders have carried out extensive surveys of the Labrador Sea and Davis Strait.

Seagliders being assembled in Nuuk, West Greenland

Seaglider surveys for two winters

The first ocean passage section by an autonomous undersea vehicle: Davis Strait, October 2004; about 2500 profiles have been completed by two Seagliders since then. In

winter 2003/4 two other gliders surveyed the Labrador Sea producing about 1500 profiles of temperature, salinity, dissolved

oxygen, chlorophyll and particle scattering.

Baffin currentcold, low salinityflows southinto Labrador Sea

Warm,saline Irmingerwaterflows northinto BaffinBay

Cold Arctic water enters the Atlantic

A key process for climate is the salinity barrier layer that forms at the top of the Labrador Sea

in spring, and controls deep convection in subsequent winter. This is visible in the next figure, as purple (cold, low salinity) water is

carried off the Greenland coast by the boundary current system.

Aqua & Terra satellite SST day 089 05

Cold shelf water (purple) streams off the Greenland shelf. Seagliders 014 and 015 are embedded in this jet

The Seagliders have ‘cat-scanned’ the Labrador Sea, documenting

-Arctic=>Atlantic transport west of Greenland-wintertime deep convection (depth,

geographical distribution)-the formation of the salinity barrier layer-the boundary current velocity and density

profiles on all sides of the Sea-remarkably fine spatial scales of the

circulation-the water-column heat storage cycle (which

constrains atmospheric observations of heat flux)

FY06 Priorities at President’s Budget $ Level

• Continue Ice Mass Balance Work

• Continue Bering St. mooring program

• Plan for repeat “RUSALCA” during IPY

• End Labrador Sea activity

• Northern Bering Sea mooring in doubt