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Distributed Biological Observatory- Northern Chukchi Integrated Study (DBO-NCIS)

Analyzing Arctic water flow and connections to biological drivers

The overall goal of the Distributed Biological Observatory – Northern Chukchi Integrated Study (DBO-NCIS) is to document and understand ongoing changes to the Pacific-Arctic ecosystem in light of changing physical drivers. The project will continue the analysis of physical data collected on the DBO-NCIS cruises to date (2017-2021), in conjunction with ancillary and historical data, while collaborating with the interdisciplinary team of scientists involved in the program. This includes a study of the changing halocline of the Beaufort Gyre, the formation and spreading of newly formed winter water on the Beaufort shelf, and the Pacific Water flow branches on the Chukchi shelf. These and other efforts have continued to advance our understanding of the water mass composition, transformation, and progression of flow from the Bering Strait to the Arctic Basin, and how this in turn impacts Arctic ecosystems.

Robert Pickart

Primary Investigator

Project Institution: Woods Hole Oceanographic Institution 

Partnerships: NSF, DBO, PAG, PMEL

Award Period: 01 October 2021 – 30 September 2022

Vessels Information: USCGC Healy,  R/V Sikuliaq, R/V Mirai, R/V Xuelong, and CCGS Amundsen

Project Mission & Goals

The DBO-NCIS project is divided into two different studies. Read more about their objectives below.

The first study addresses the evolution of the Beaufort Gyre over the past two decades. Results imply that continued thinning of the cold halocline layer could disrupt the present stable state of the gyre, allowing for a significant freshwater release. This in turn could freshen the subpolar North Atlantic, impacting the Atlantic Meridional Overturning Circulation.

Newly ventilated winter water observed across four moorings deployed across the shelf in the western Beaufort Sea (2008-2009). While water near the freezing point was observed across the entire shelf (grey dots), only on the inner-shelf (moorings N1 and N2) was the water salty enough to ventilate the cold halocline layer of the Canada Basin (black dots).

The second study investigates aspects of newly ventilated winter water (NVWW), which is a cold, salty, nutrient-rich water mass that is critical for supporting the ecosystem of the western Arctic Ocean. The analysis includes using time series from a previous mooring array deployed across the shelf and slope in the western Beaufort Sea near 150°W from 2008-9. Results show that the salty NVWW can be fluxed off the shelf due to the convergence of the westward-flowing current on the shelf and the eastward-flowing outflow from Barrow Canyon.

In addition to these studies, we are compiling and updating an historical database of shipboard acoustic Doppler current profiler (SADCP) data on the Chukchi shelf. The climatology is called ChukSA (Chukchi Sea shipboard ADCP), and to date it includes data from 57 cruises over the time period 2002-2022. We will continue to expand this database using data from both domestic and foreign vessels, including the R/V Marai (JAMSTEC), the R/V Xue Long (PRIC), the USCGC Healy, and the CCGS Laurier (DFO). We are also including ADCP data from Saildrones. Such a composite data set is extremely valuable for quantifying the basic circulation of the Chukchi shelf, its response to wind forcing, and the fluxes of volume, heat, salt, and nutrients across the shelf. 

Data Access

About The DBO-NCIS Database

This data has been collected and submitted as part of the Distributed Biological Observatory (DBO) program. Data were originally collected as part of the Distributed Biological Observatory – Northern Chukchi Integrated Study (DBO-NCIS) project, headed by Robert Pickart ( and Jackie Grebmeier ( Conductivity-Temperature-Depth (CTD) data were taken aboard the USCGC Healy during HLY1702. During this cruise, data were taken along the established repeat hydrography transects, DBO1, DBO3, DBO4, and DBO5. This submission includes CTD data from the DBO3 transect. There are nine dcc data files containing the following parameters: pressure, depth, temperature, conductivity, oxygen, fluorescence, practical salinity, density, and potential temperature.


ADC DBO Chukchi Data Portal

Healy 2017 (HLY-1702) Data

Healy 2018 (HLY-1801) Data

Healy 2019 (HLY-1901) Data/ ChukSA climatology

Trends of volume in the BG region (curves) and in the main source water at the mouth of Barrow Canyon (BC, filled circles), in the early period (2003–2011, blue) and the late period (2012–2019, orange). The 95% confidence intervals of the trends are denoted by the dashed lines and horizontal bars.

Featured Publication

Recent state transition of the Arctic Ocean’s Beaufort Gyre

May 8, 2023

Peigen Lin, Robert S. Pickart, Harry Heorton, Michael Tsamados, Motoyo Itoh, & Takashi Kikuchi

The Beaufort Gyre is the dominant circulation of the Canada Basin and the largest freshwater reservoir in the Arctic Ocean. During the first part of the 2000s, the gyre intensified and accumulated freshwater. Using an extensive hydrographic dataset from 2003 to 2019, along with updated satellite ocean topography data, we find that over the past decade, the Beaufort Gyre has transitioned to a quasi-stable state in which the increase in sea surface height of the gyre has slowed and the freshwater content has plateaued. In addition, the cold halocline layer, which isolates the warm/salty Atlantic water at depth, has thinned significantly due to less cold and salty water stemming from the Pacific Ocean and the Chukchi Sea shelf. This, in turn, could significantly freshen subpolar North Atlantic waters.

Publications & References

Anderson, D. M., E. Fachon, K. Hubbard, K. A. Lefebvre, P. Lin, R. S. Pickart, M.Richlen, G. Sheffield, and C. Van Hemert, 2022. Harmful algal blooms in the Alaskan Arctic: an emerging threat as oceans warm. Oceanography, 35,
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Danielson, S. L., J. M Grebmeier, K. Iken, C. Berchok, L. Britt, K. H. Dunton, L. Eisner, E. Farley, A. Fujiwara, D. Hauser, M. Itoh, T. Kikuchi, S. Kotwicki, K. J. Kuletz, C. W. Mordy, S. Nishino, C. Peralta-Ferriz, R. S. Pickart, P. S. Stabeno, K. M. Stafford, A. V. Whiting, and R. Woodgate, 2022. Monitoring Alaskan Arctic shelf ecosystems through collaborative observation networks. Oceanography, 35,
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Einarsson, S.V., K Lowry, P. Lin, R.S. Pickart, and C.J. Ashjian, 2022. Alexandrium on the Alaskan Beaufort Sea Shelf: Impact of upwelling in a warming Arctic. Harmful Algae, 120,
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Hubbard, K.A. and 16 co-authors. Spatiotemporal transitions in Pseudo-nitzschia species assemblages and domoic acid along the Alaska coast. PLOS ONE. 18(3):e0282794.
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Lefebvre, K.A. and 20 co-authors, 2022. Paralytic shellfish toxins 1 in Alaskan Arctic food webs during the anomalously warm ocean conditions of 2019 and estimated toxin doses to Pacific walruses and bowhead whales. Harmful Algae, 114,
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Lin, P., R.S. Pickart, T.J. Weingartner, H.L. Simmons, M. Itoh, and T. Kikuchi. Formation and circulation of Newly Ventilated Winter Water in the western Beaufort Sea. Progress in Oceanography, 216, 103068.
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Lin, P., Pickart, R.S., Heorton, H. et al. Recent state transition of the Arctic Ocean’s Beaufort Gyre. Nat. Geosci. 16, 485–491 (2023).
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Selden, C.R., S.V. Einarsson, K. Lowry, K. Crider, R.S. Pickart, P. Lin, C. Ashjian, and P. D. Chappell, 2022. Coastal upwelling enhances abundance of a symbiotic diazotroph (UCYN-A) and its haptophyte host in the Arctic Ocean. Frontiers in Marine Science, Front, 9:877562.
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von Appen, W-J., T. Baumann, M. Janout, N. Koldunov, Y-D Lenn, R.S. Pickart, R.B Scott, and Q. Wang, 2022. Eddies and the distribution of eddy kinetic energy in the Arctic Ocean. Oceanography, 35,
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Wang, H., P. Lin, R.S. Pickart, and J.N. Cross, 2022. Summer surface CO2 changes in the Bering and Chukchi Seas from 1989 to 2019. Journal of Geophysical Research, 127, e2021JC017424.
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2022 Alaska SeaGrant: Beyond Bering Strait: Where Does the Water Go? Strait Science, November 24, 2022
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DBO-NCIS Project Website
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