Abstract The Beaufort Gyre is a key circulation system of the Arctic Ocean and its main reservoir freshwater. Freshwater storage release affects sea ice cover, as well North Atlantic global climate. We describe mechanism that fundamental to dynamics gyre, namely, ice‐ocean stress governor . Wind blows over ice, drags ocean. But gyre spins up, currents catch up turn off surface stress. This sets basic properties such depth, freshwater content, strength. Analytical numerical modeling employed...

Abstract We present observational estimates of Ekman pumping in the Beaufort Gyre region. Averaged over Canada Basin, results show a 2003–14 average 2.3 m yr −1 downward with strong seasonal and interannual variability superimposed: monthly yearly means range from 30 to 10 upward. A clear, cycle is evident intense downwelling autumn upwelling during winter months, despite wind forcing being favorable year-round. Wintertime associated friction between large-scale ocean circulation surface ice...

Abstract Observations of ocean currents in the Arctic interior show a curious, and hitherto unexplained, vertical temporal distribution mesoscale activity. A marked seasonal cycle is found close to surface: strong eddy activity during summer, observed from both satellites moorings, followed by very quiet winters. In contrast, subsurface eddies persist all year long within deeper halocline below. Informed baroclinic instability analysis, we explore origin evolution seasonally ice-covered...

Abstract The Beaufort Gyre in the Arctic Ocean has spun up over past two decades response to changes of wind forcing and sea ice conditions, accumulating a significant amount freshwater. Here simulation performed with high-resolution, eddy-resolving model is analyzed order provide detailed description total eddy kinetic energy their this spinup gyre. On average, contrast typical open ocean levels mean are same magnitude, only intensified along boundary subsurface. In strong anomalous...

Abstract Using Ekman pumping rates mediated by sea ice in the Arctic Ocean's Beaufort Gyre (BG), magnitude of lateral eddy diffusivities required to balance downward is inferred. In this limit—that vanishing residual‐mean circulation—eddy‐induced upwelling exactly balances pumping. The implied diffusivity varies spatially and decays with depth, values 50–400 m 2 /s. Eddy estimated using mixing length theory applied BG mooring data exhibits a similar decay depth range from 100 /s more than...

Abstract The Beaufort Gyre (BG) is a large anticyclonic circulation in the Arctic Ocean. Its strength directly related to halocline depth, and therefore also storage of freshwater. It has recently been proposed that equilibrium state BG set by Ice‐Ocean Governor, negative feedback between surface currents ice‐ocean stress, rather than balance lateral mesoscale eddy fluxes Ekman pumping. However, eddies are present Ocean; it important extend Governor theory include due eddies. Here, nonlinear...

The stratification of the Arctic Ocean plays a central role in regulating impact climate change on Arctic. Though eastern Eurasian Basin halocline is known to have weakened since 2000s, variability over full AW depth range whole has been little explored.Our analysis aims combine available in-situ observations characterize regional changes past four decades. We find that, both Nansen and Amundsen basins, temperature salinity most pronounced thermocline that separates Atlantic Water (AW) core...

Abstract Based on analysis of observational data it has been suggested that a negative feedback ice–ocean stress coupling may limit freshwater accumulation in the Beaufort Gyre (BG). In this paper we explore how can significantly contribute to BG stabilization an anticyclonic wind regime. We use model and turn off simulations elucidate role feedback. When persistent anomaly is applied over BG, liquid content (FWC) increases because enhanced Ekman downwelling. As consequence, ocean surface...

Abstract The seasonal ice zone around both the Arctic and Antarctic coasts is typically characterized by warm salty waters underlying a cold fresh layer that insulates sea‐ice floating at surface from vertical heat fluxes. Here, we explore how mesoscale eddy field rubbing against can, through Ekman‐induced motion, bring up to partially melt ice. We dub this “Eddy‐Ice‐Pumping” (EIP) mechanism. When relatively motionless, eddies experience drag generates Ekman upwelling in anticyclones...

Abstract In the Arctic Basin, ocean dynamics at mesoscale and submesoscale under sea ice are poorly quantified understood. Here, we analyze comprehensive data sets from Ice Tethered Profilers moorings Beaufort Gyre Observing System spanning period 2004–2019 in order to characterize space time variations of (sub)mesoscale flow. seasonally ice‐covered regions, surface layer is largely determined by presence ice, with an increased eddy kinetic energy numerous eddies summer. Beyond these...

Abstract Observations of Ekman pumping, sea surface height anomaly, and isohaline depth anomaly over the Beaufort Gyre are used to explore relative importance role (i) feedbacks between ice ocean currents, dubbed “ice–ocean governor,” (ii) mesoscale eddy processes in equilibration Gyre. A two-layer model gyre is fit observations mechanisms governing evolution from monthly decennial time scale. The ice–ocean governor dominates response on interannual scales, with becoming evident only...

Abstract We use ocean observations and reanalyses to investigate the subseasonal predictability of summer fall sea ice area (SIA) in western Arctic Ocean associated with lateral heat transport (OHT) through Bering Strait vertical OHT along Alaskan coastline from Ekman divergence upwelling. Results show predictive skill spring anomalies Chukchi Sea eastern East Siberian for June July SIA, followed by a sharp drop August, September, October resurgence correlation November during freeze-up....

We explore the origin and evolution of mesoscale eddies in seasonally ice-covered interior Arctic Ocean. Observations ocean currents show a curious, hitherto unexplained, vertical temporal distribution activity. A marked seasonal cycle is found close to surface: strong eddy activity during summer, observed from both satellites moorings, followed by very quiet winters. In contrast, subsurface persist all year long within deeper halocline below. find that surface controlled friction with sea...

We infer circumpolar maps of stress imparted to the ocean by wind, mediated sea-ice, in and around Seasonal Ice Zone (SIZ) Antarctica. In open we compute wind using surface winds from daily atmospheric reanalyses applying bulk formulae. presence sea ice, underlying is computed satellite observations ice concentration drift velocity assuming, first, that geostrophic currents beneath are negligible, then including inferred altimetry. this way SIZ obtained. The discussed interpreted, their...

A global stability analysis of the boundary layer in leading edge a swept wing is performed incompressible flow regime. It demonstrated that eigenfunctions display features characterizing local instability attachment line, as Hiemenz flow, and those cross-flow instabilities further downstream along wing. continuous connection chordwise direction established between two eigenfunctions. An adjoint-based receptivity reveals eigenfunction most responsive to forcing applied immediate vicinity...

Accurate long-term forecasts of the path and intensity severe hurricanes are imperative to protect property save lives. Extensive real-time measurements within hurricanes, especially near their core, essential for supplementing limited relevant information accessible by satellites in order improve such forecasts. Current operational methods obtaining situ information, as dropsondes repeated manned unmanned aircraft flights over both expensive duration. In present work it is demonstrated...