The Western Arctic from the CBL 2002 cruise
PSC logo
With thanks to:
NSF logo   ONR


Observational-based Studies of Physical Processes in Ice-covered Waters, especially the Arctic

Rebecca Woodgate
                          Peralta Ferriz
Cecilia Peralta-Ferriz

Jim Johnson
Polar Science Center, Applied Physics Laboratory,
University of Washington
1013 NE 40th Street, Seattle, WA 98105, U.S.A.


Arctic and sub-Arctic mechanisms explaining observed increasing northward flow through the Bering Strait and why models may be getting it wrong
Peralta-Ferriz and Woodgate, 2023, Geophysical Research Letters

Warming and Freshening of the Pacific Inflow to the Arctic from 1990-2019 implying dramatic shoaling in Pacific Winter Water Ventilation of the Arctic water column
Woodgate and Peralta-Ferriz, 2021, Geophysical Research Letters

Freshening of the Pacific Inflow to the Arctic
(Woodgate, 2020, ASOF meeting presentation)

Bering Strait Mooring Cruise 2023

The dominant role of the East Siberian Sea in driving the oceanic flow through the Bering Strait - conclusions from GRACE ocean mass satellite data and in situ mooring observations between 2002 and 2016
Peralta-Ferriz and Woodgate, 2017, Geophysical Research Letters

Increases in the Pacific inflow to the Arctic from 1990 to 2015, and insights into seasonal trends and driving mechanisms from year-round Bering Strait mooring data
Woodgate, 2018, Progress in Oceanography

Seasonality and forcing factors of the Alaskan Coastal Current in the Bering Strait from July 2011 to July 2012
Brett Morris, UW MSc Thesis, June 2019

The Changing Arctic Ocean (Ocean 508/482)
- website for UW interdisciplinary graduate/senior undergraduate course
by Jody Deming and Rebecca Woodgate, Spring Quarter 2016

Bering Strait Mooring Cruise 2015 - including "Tales from the Bering Strait" Daily Cruise Blog

A Synthesis of Year-round Interdisciplinary Mooring Measurements in the Bering Strait (1990-2014) and the RUSALCA years (2004-2011)
Woodgate, Stafford and Prahl, 2015, Oceanography

Seasonal and Interannual variability of the Arctic surface Mixed Layer
- from 1979 to 2012 from hydrographic observations
Peralta-Ferriz and Woodgate, 2015, Progress in Oceanography

Arctic Change (Ocean 235)
(Spring 2021)
- website for UW interdisciplinary undergraduate course, core course
for UW's Arctic Studies Minor

Polar Fridays BBL
(Lunches with Polar Science Talks)

(Discussions about fieldwork challenges)

Respect and Equality in Fieldwork
(links and UW report)

And something different:

Change Ringing at the
University of Washington

Quick links





Bering Strait - Pacific Gateway
International Polar Year Bering Strait

Atlantic Waters in the Western Arctic
Changing Seasonality of the Arctic Ocean
BEST - Bering Sea
Ecosystem STudy

Chukchi Borderland - Arctic Crossroads

SBI Chukchi
North Pole Environmental Observatory
Arctic Circulation at the Lomonosov Ridge
St.Lawrence Polynya
Fram Strait
Beaufort Sea
Lake Superior
Arctic change from Russian Data
(full list below)

Bering Strait
   2023   2022
   2021   2020
   2019   2018
   2017   2016
   2015   2014
   2013   2012
   2011   2010
   2009   2008
   2007   2006
   2005   2004
   2003   2002
   2001   2000

North Pole Camp

SBI 2003 Mooring Cruise

(Chukchi Borderland)


Polar Science Weekend: The Future of Arctic Sea-Ice
(2007 Polar Science Weekend Website)

Arctic and sub-Arctic mechanisms explaining observed increasing northward flow through the Bering Strait and why models may be getting it wrong
Peralta-Ferriz and Woodgate, May 2023, submitted to Geophysical Research Letters

Warming and Freshening of the Pacific Inflow to the Arctic from 1990-2019 implying dramatic shoaling in Pacific Winter Water ventilation of the Arctic water column
Woodgate and Peralta-Ferriz, 2021, Geophysical Research Letters

Freshening of the Pacific inflow to the Arctic,
Woodgate, 2020, ASOF presentation and paper in preparation

Seasonality and forcing factors of the Alaskan Coastal Current in the Bering Strait from July 2011 to July 2012
Morris 2019 MSc Thesis

Variability, trends, and predictability of seasonal sea ice retreat and advance in the Chukchi Sea
Serreze, Crawford, Stroeve, Barrett, and Woodgate, (2016, JGR)

A Synthesis of Year-round Interdisciplinary Mooring Measurements in the Bering strait (1990-2014) and the RUSALCA years (2004-2011)
Woodgate, Stafford and Prahl (2015, Oceanography)

Seasonal and interannual variability of pan-Arctic surface mixed layer properties from 1979 to 2012 from hydrographic data
Peralta-Ferriz and Woodgate (2015, Progress in Oceanography)

Observed increase in Bering Strait oceanic fluxes from the Pacific to the Arctic from 2001 to 2011 and their impact on the Arctic Ocean water column
Woodgate et al, 2012

Quantifying Sea-Ice Volume Flux using Moored Instrumentation in the Bering Strait
Travers 2012 MSc Thesis

Arctic Ocean Circulation - going around at the Top of the World Woodgate 2012, Nature Education Knowledge Project

A Synthesis of Exchanges Through The Main Oceanic Gateways to the Arctic Ocean Beszczynska-Moeller et al., Oceanography, 2011.

The 2007 Bering Strait Oceanic Heat Flux and anomalous Arctic Sea-ice retreat (Woodgate et al., GRL, 2010)

Interannual changes in Bering Strait Fluxes (Woodgate et al., GRL, 2006)
Atlantic Water Circulation in the Chukchi Borderland Region (Woodgate et al., JGR, 2007)
Pacific Ventilation of the Arctic (Woodgate et al., GRL, 2005)
A Year in the Chukchi Sea (Woodgate et al., DSR, 2005)
Influence of sea-ice on ocean heat uptake during increasing CO2 (Bitz et al., JClim, 2006)
Bering Strait Freshwater Flux (Woodgate & Aagaard., GRL, 2005)
Bering Strait Climatology (Woodgate et al., GRL, 2005)

Bering Strait

On-line CBL Archive

On-line Chukchi Sea and SBI Archive


1990-1991 Chukchi Data

1995-1996 Lomonosov Data

Data are also archived at national archives, including ADCC and NODC


We aim to study and understand:

- physical processes in the high latitude oceans,
including large-scale circulation, shelf-basin interactions, and water mass formation ;

- linkages between polar oceans and the lower latitudes ;
- the role of polar processes in climate.

We do this primarily with observations, drawing on theory and modelling results to explain processes we observe.

Our primary tools are subsurface moorings in ice-covered waters.
A mooring is a independent measurement platform.  It consists of rope or chain, anchored to the sea floor, and held upright by various subsurface floatation devices.  To this rope or chain, we attach scientific instruments that measure many things, mostly water temperature and salinity, and water velocity, but also sometimes ice thickness, ice motion, and water chemistry.  The top of the mooring is subsurface as the sea-ice will likely destroy any surface float.  This means the data cannot be transmitted to satellite, and thus to recover the data we must recover the mooring.  Usually, we deploy these moorings for 1 year, deploying and recovering by ship in the most ice free season.  The exception is the North Pole Mooring.  This mooring is deployed and recovered from a camp on the floating sea-ice, and this takes place in the spring.

(Right: Schematic of a mooring, this is one of the Bering Strait moorings.)
Schematic of short mooring

CTD going
                            into water from CBL2002

CTD Rosette entering the water on CBL2002 cruise
(more images)
We also use CTD data. 
CTD stands for "Conductivity and Temperature with Depth".  It is an instrument that can be lowered to the sea floor on a conducting wire and measures profiles of ocean properties, such as temperature, conductivity (and hence salinity), and sometimes turbidity, dissolved oxygen and nutrients.  Usually, the CTD instrument is attached to a water-sampling rosette.  This consists of a set of plastic bottles.  From the ship, we can send a signal down the conducting wire and close the bottles at different water depths, thus taking a sample of water from that depth.  This water is the analyzed either on the ship or back in the lab for various chemical tracers, such as salinity, dissolved oxygen, nutrients, CFCs, and many other things. 
Sampling from the Rosette CBL2002

Taking water samples on CBL2002 cruise
(more images)

We analyze the data from the moorings and from the CTD using geophysical fluid dynamics, and compare results with simulations from numerical models.


At any time, we work on many different projects.

Bering Strait - Pacific Gateway - The ~ 85 km wide, ~ 50 m deep Bering Strait, at the northern end of the Pacific Ocean, is the only oceanic link between the Pacific and the Arctic.  The flow through the strait is  (in the mean) northwards, and is an important source of freshwater, heat and nutrients for the Arctic Ocean.  Recent measurements suggest an increase in heat flux through the strait.  We aim to measure and quantify the Bering Strait fluxes of heat, freshwater and nutrients, and provide a measurement platform for other studies in the region.

Atlantic Waters in the Western Arctic Ocean -
Atlantic Waters (AWs) are volumetrically the largest inflow to the Arctic Ocean.  They form the major subsurface circum-arctic oceanic transport system and ventilate the interior basins.  They are the greatest pan-arctic reservoir of oceanic heat, which may influence upper layers and the sea-ice, for example through slope upwelling and mixing.  Circulation of AW carries tracers and contaminants through the Arctic, and the pan-arctic distribution of AW offers a warm corridor for invasive species.  Globally, arctic-modification of AW contributes to the North Atlantic overflows and is a high-latitude (climate-sensitive) part of the meridional overturning circulation.  This project uses mooring and CTD data from the last 3 decades to elucidate hitherto-unknown aspects of the Atlantic Water circulation in the western Arctic. 

Changing Seasonality of the Arctic Ocean  The Arctic Ocean is (or at least has been) a remarkably quiet place, where ocean currents are sluggish and molecular-scale processes can have basin-scale manifestations.  Yet, with retreating summer sea-ice exposing ~ 60% of the Arctic ocean to the seasonal effects of wind, all this may be about to change.  This interdisciplinary project addresses potential impacts of increases wind-driven mixing on the internal wave field of the Arctic, with implications for changing stratification and impacts on Arctic ecosystems at the bottom of the foodchain.

BEST - Bering Sea Ecosystem Study - The Bering Sea - lying at the northern end of the Pacific Ocean and north of the Aleutian Chain - is the source of over 50% of the total US fish catch and the home to immense populations of birds and marine mammals. The Bering Sea ecosystem is strongly tied to the seasonal sea-ice, which influences the oceanic environment of the region and also provides a habitat for many species. Recent years have shown significant climate regime shifts in the Bering Sea. As part of the new NSF Bering Ecosystem Study (BEST), we plan to use a state-of-the-art numerical ocean-ice model to investigate prior (and predict future) changes in the Bering Sea ice cover and study the impacts of these changes on Bering Sea marine and eco-systems.
Chukchi Borderland - Arctic Crossroads - Some 600 miles north of the Bering Strait, about 800 miles south of the north pole, is a region of complex sea floor topography known as the Chukchi Borderland.  In this region, the nutrient-rich Pacific waters from the Bering Strait meet and interact with the warmer saltier Atlantic waters that entered the Arctic via Fram Strait.  Recent results show that a warming of the Fram Strait waters reached this region in the early 2000s.  In 2002, we performed an intensive hydrographic survey of the Chukchi Borderland region, to elucidate water mass pathways and important physical processes. 
SBI Chukchi - The Chukchi Sea, ~ 500 km wide (east-west) and ~ 800 km long (north-south) is a shallow (~ 50 m deep) shelf sea just north of the Bering Strait and south of the Arctic Ocean proper.  It is fed from the south by the Pacific water throughflow through the Bering Strait.  As part of the SBI (Shelf-Basin-Interaction) project, we have been studying the flow and transformation of waters in the Chukchi Sea, and measuring pathways, volume and water properties of the Pacific waters that exit the Chukchi Sea into the Arctic Ocean.

North Pole Environmental Observatory- As part of this long term observatory, we are maintaining a subsurface mooring at the North Pole.  This mooring is anchored to the sea floor and stretches to within 50 m of the surface.  This makes it over 4km (2.5 miles) long.  The mooring measures water velocity and water properties in the major layers of the Arctic Ocean (the upper halocline layer, the lower Atlantic layer, and the deeper layers), and also records ice thickness and ice motion.
Arctic Circulation at the Lomonosov Ridge - The major circum Arctic ocean circulation pathway is the Arctic Ocean Boundary Current, an equivalent barotropic current that moves cyclonically (anticlockwise) along the continental shelves of the major ocean basins.  Using mooring data from 1995 to 1996 from the Eurasian end of the Lomonosov Ridge, we study how the Lomonosov Ridge splits the Arctic Ocean Boundary Current, with about half the boundary current moving north along the ridge and the other half continuing along the continental slope.
St.Lawrence Polynya - In the northern Bering Sea, when atmospheric conditions are right in winter, a major ocean polynya forms just south of St. Lawrence Island.  A dedicated field effort, including year-round moored instrumentation, tested theoretical ideas about shelf convection and the spreading of ventilated water away from the convecting region.
Fram Strait - On the European side of the Arctic, the Fram Strait is the major deep entrance to the Arctic ocean and the primary southward conduit for Arctic freshwater (in the form of water or ice) into the Greenland Sea and North Atlantic.  In a joint US-American project, we have measured year-round ice thickness and studied the primary mechanisms controlling the ice flux through the Fram Strait.
Beaufort Sea - Circulation in the Beaufort Sea, with an emphasis on the Boundary Current
Lake Superior - Circulation, convection and frontal processes in Lake Superior.
Arctic change from Russian Data - Interannual and decadal variability of temperature and other water properties from an enhanced version of the 1948-1993 data released under the Gore-Chernomyrdin environmental bilateral agreement.

  The Arctic map below gives the locations of these main projects.

FS=Fram Strait

NP=North Pole Mooring

LR= The Arctic Ocean Boundary Current at the Lomonosov Ridge

BF= Beaufort Sea

CH=Chukchi Sea

BS = Bering Strait

StL=St Lawrence Island

CBL=Chukchi Borderland


Every year, we engage in different field efforts for our various research projects.  Most of our work is ship-based, on cruises which are either dedicated to our project or serving many projects.  We also take part in the North Pole field camps, to recover and deploy the North Pole mooring. On some field expeditions, we take along a school teacher, who participates in the science of the cruise and writes a daily web-diary for their classes (and other classes) back on land.  If you would like to be that teacher, please contact us
Links below are to project pages, to individual cruise websites (both science websites and websites for schools) and to individual cruise reports.
RV Alpha Helix
RV Alpha Helix, from Seward, USA

CCGS Sir Wilfrid Laurier
CCGS Sir Wilfrid Laurier, from Victoria, Canada

- 2010 Mooring Cruise, RV Khromov
- 2009 Mooring Cruise, RV Khromov
- 2008 Mooring Cruise, RV Lavrentiev
- 2007 Mooring Cruise, RV Sever
- 2006 Mooring Cruise, CCGS Sir Wilfrid Laurier
- 2005 Mooring Cruise, CCGS Sir Wilfrid Laurier
- 2004 Mooring Cruise, RV Alpha Helix
- 2003 Mooring Cruise, RV Alpha Helix
- 2002 Mooring Cruise, RV Alpha Helix
- 2001 Mooring Cruise, RV Alpha Helix
- 2000 Mooring Cruise, RV Alpha Helix

- science website
- website for schools

CBL2002 (Chukchi Borderland), USCGC Polar Star
- science website
- website for schools

- 2006 North Pole Camp

USCGC Polar Star
USCGC Polar Star, from Seattle, USA

  USCGC Healy
USCGC Healy, from Seattle, USA
We gratefully acknowledge financial support for this work from the National Science Foundation (NSF), the Office of Naval Research (ONR), the National Oceanic and Atmospheric Administration (NOAA) and the Minerals Management Service (MMS).