The performance of two vertical mixing parameterizations in idealized continental shelf settings is analyzed to assess what aspects and under conditions they differ. level 2.5 Mellor‐Yamada turbulence closure (M‐Y) compared with an enhanced version the K profile parameterization (KPP), which has been appended include a representation bottom boundary layer. schemes are wind‐driven one‐ two‐dimensional shallow ocean examine differences (1) surface layer response, (2) response when layers close...

Sea ice is made up of individual pieces called floes, and these floes can vary in size from scales just metres to tens kilometres. There has been much recent interest simulating variable floe continuum models sea ice, since impact the evolution cover via several mechanisms including lateral melt volume, rheology, momentum exchange. These simulations usually only account for breakup driven by waves. Observations Arctic show that there also exists in-plane failure resulting processes wind...

Abstract A primitive equation model is used to study the finite-amplitude evolution of instabilities associated with coastal upwelling front. Simulations increasing complexity are examined that represent idealizations summer conditions off Oregon coast, including cases steady and time-variable wind in a domain alongshore-uniform bathymetry realistic coast bathymetry. The numerical results indicate fastest-growing mode this system has approximately an 8–10-km alongshore wavelength but that,...

Abstract The dependence of surface-current damping on the definition surface current for relative wind is examined in coupled ocean–atmosphere numerical simulations northern California Current System (nCCS) during March–October 2009. model response analyzed stress computed from six different choices effective velocity. Simulations without coupling are also considered. As a function geographically varying uppermost grid-level depth, velocity found to have wind-drift component with log-layer...

Abstract Observations have suggested a trend of decreasing dissolved oxygen (DO) and increasing spiciness in summertime middepth slope waters bottom shelf along the United States west coast over past 50 years, but they also demonstrated large amount interannual decadal variability. Shelf water properties can be influenced by both local remote effects, including changes circulation or characteristics source supplying region. A regional‐scale, coupled physical biogeochemical model has been...

Abstract The influence of mesoscale sea surface temperature (SST) variations on wind stress and boundary layer winds is examined from coupled ocean–atmosphere numerical simulations satellite observations the northern California Current System. Model coupling coefficients relating divergence curl to downwind crosswind SST gradients are generally smaller than observed values vary by a factor 2 depending planetary (PBL) scheme, with larger for smoothed fields 0.25° observational grid unsmoothed...

Abstract Nonlinear model simulations of a coastal upwelling system show frontal instabilities that initiate at short alongshore scales but rapidly evolve to longer wavelengths. Several factors associated with the nonstationarity this basic state contribute progression in scale. A portion evolution is external forcing. Another alteration mean flow resulting from wave growth. Direct interactions between finite-amplitude disturbances also promote emergence new scales. The relative role each...

Abstract The linear stability of a nearly time-periodic, nonlinear, coastal upwelling–downwelling circulation, over alongshore-uniform topography, driven by time-periodic wind stress is investigated using numerical methods. near-periodic basic flow obtained forcing primitive equation model ocean circulation with periodic stress. Disturbance growth on this explored in and nonlinear simulations. Numerous growing normal modes are found the analyses at alongshore scales between 4 24 km. These...

Abstract Fog and low-level stratus during April through September 2009 are examined in a set of coupled ocean-atmosphere numerical simulations the northern California Current System (CCS). The model configurations differ only choice planetary boundary layer (PBL) parameterization scheme and, one case, surface flux scheme. results suggest that fog formation this region primarily occurs condensation at induced locally by cooling, when moist offshore air is advected over cold upwelled waters...

Sea ice floe size can impact several processes that determine the evolution of Arctic sea ice, including lateral melt volume, momentum exchange, and rheology. Floe distribution (FSD) models are applied within continuum to capture FSD through parameterisations modify such as melting wave break-up floes. do not yet adequately resolve in-plane fragmentation floes breakup under wind forcing, interactions between neighbouring floes, or thermal weakening. It is challenging characterise therefore...

Abstract A 2‐km resolution ocean circulation model for the Eastern Bering Sea is utilized to understand whether and where slope‐interior exchange along path of Aleutian North Slope Current helps maintain subsurface temperature maximum on 26.8‐kg/m 3 isopycnal surface in Basin, at approximately 300–400‐m depths. simulation June–October 2009 shows warmer water advecting westward this southern slope Islands, through Amchitka Pass (180°W), then eastward northern as season progresses, reaching...