The Arctic Ocean's Beaufort Gyre

Abstract

The Arctic Ocean's Beaufort Gyre is a dominant feature of the Arctic system, a prominent indicator of climate change, and possibly a control factor for high-latitude climate. The state of knowledge of the wind-driven Beaufort Gyre is reviewed here, including its forcing, relationship to sea-ice cover, source waters, circulation, and energetics. Recent decades have seen pronounced change in all elements of the Beaufort Gyre system. Sea-ice losses have accompanied an intensification of the gyre circulation and increasing heat and freshwater content. Present understanding of these changes is evaluated, and time series of heat and freshwater content are updated to include the most recent observations. Expected final online publication date for the Annual Review of Marine Science, Volume 15 is January 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Response of nutrients and primary production to high wind and upwelling-favorable wind in the Arctic Ocean: A modeling perspective

“…The strong vertical stratification caused by the accumulation of freshwater (Proshutinsky et al, 2009) prevents the upward transport of high NO 3 from subsurface Pacific summer waters (Tremblay et al, 2008;Timmermans and Toole, 2022). Modeled NO 3 is low (<2 mmol/m 3 ) in most areas of the surface and subsurface layers, and higher (>8 mmol/m 3 ) below the subsurface layer to 110 m. NO 3 in the south (<73.5°N) is higher (<12-16 mmol/ m 3 ) than in the north (<8-10 mmol/m 3 ) (Figures 10A, B).…”

Surface and Interior Dynamics of Arctic Seas Using Surface Quasi-Geostrophic Approach

“…As for the Nordic Seas, the SSB reconstruction shows less mesoscale circulation structures in the Beaufort Sea (Figure 6) than the SSH and SSV reconstructions. Two features clearly resolved by the SSB approach are the NE surface current of Pacific waters entering the Beaufort Sea along the Alaskan coast (structure 1 in Figure 6), and an undefined but large structure associated with the Mackenzie discharge plume (∼70ºN, ∼135ºW, structure 2 in Figure 6), which can be related to water subduction (negative vertical Ekman pumping) [84]. SSH and SSV reconstructions, however, perform better than SSB, showing several mesoscale structures at finer scales [85].…”

Declining O2 in the Canada Basin Halocline Consistent With Physical and Biogeochemical Effects of Pacific Summer Water Warming

“…This transition to low 𝐴𝐴 O2 from south to north relates to the transition from the Pacific halocline to the Eurasian Basin halocline (Timmermans et al, 2010), and is commensurate with a thinner layer in the north compared to the south (Figures 2g-2i). Note that the PSW is thickest in the CCB (Figures 2g-2i); its bottom bounding isohaline is up to 100 m deeper there in comparison to its margins (see Timmermans & Toole, 2023).…”

“…Water sourcing from the Pacific Ocean has two variants: warm Pacific Summer Water (PSW), which ventilates the CB halocline during the summer to reside immediately beneath the CB mixed layer and Pacific Winter Water (PWW), which ventilates the CB in winter to reside under the PSW layer (e.g., Coachman & Barnes, 1961;Steele et al, 2004;Timmermans et al, 2014Timmermans et al, , 2017; see Figure 1b. One of the most prominent recent changes in the CB has been a substantial increase in heat content of the CB PSW layer, which has approximately doubled over 2003(Timmermans & Toole, 2023Timmermans et al, 2018). Here we explore the distribution and evolution of dissolved oxygen (O 2 ) of the PSW as it relates to temperature, salinity, and nutrients to better understand its pathways and governing processes.…”