Variability of pigment biomass in the California Current System as determined by satellite imagery: 1. Spatial variability

AbstractThe California Undercurrent (CUC) transport, with significant variability ranging from weeks to decades, has consequences for both the climate and biogeochemistry of the California Current system. This study evaluates the governors of the CUC transport and its temporal variability from a momentum perspective, using a mesoscale-resolving regional model. From a 16-year mean perspective, the along-isobath pressure gradient acts to accelerate the CUC, whereas eddy advection retards it. The topographic form stress, which is part of the volume integrated along-isobath pressure gradient, not only acts in the direction of the time-mean CUC, but also greatly modulates the temporal variability of the CUC transport. This temporal variability is also correlated with the eddy momentum advection. The eddy stress plays a role in transferring both the equatorward wind stress and poleward CUC momentum downward. A theory is formulated to show that, in addition to the conventional vertical redistribution of momentum, the eddy stress can also redistribute momentum horizontally in the area where the correlation between the pressure anomaly and isopycnal fluctuations has large spatial variability.

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Faculty Opinions recommendation of Rapid progression of ocean acidification in the California Current System.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717953148.793458716 ◽

2012 ◽

Author(s):

Russell Moll

Keyword(s):

Ocean Acidification ◽

Current System ◽

California Current ◽

Rapid Progression ◽

California Current System

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Improved Ecosystem Predictions of the California Current System via Accurate Light Calculations

10.21236/ada557196 ◽

2011 ◽

Author(s):

Curtis D. Mobley

Keyword(s):

Current System ◽

California Current ◽

California Current System

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Reconstruction of Diffusion Coefficients and Power Exponents from Single Lagrangian Trajectories

Fluids ◽

10.3390/fluids6030111 ◽

2021 ◽

Vol 6 (3) ◽

pp. 111

Author(s):

Leonid M. Ivanov ◽

Collins A. Collins ◽

Tetyana Margolina

Keyword(s):

Black Sea ◽

Diffusion Coefficients ◽

Current System ◽

Mean Square Displacement ◽

California Current ◽

The Black Sea ◽

Mean Square ◽

California Current System ◽

The Mean ◽

Non Gaussian

Using discrete wavelets, a novel technique is developed to estimate turbulent diffusion coefficients and power exponents from single Lagrangian particle trajectories. The technique differs from the classical approach (Davis (1991)’s technique) because averaging over a statistical ensemble of the mean square displacement (<X2>) is replaced by averaging along a single Lagrangian trajectory X(t) = {X(t), Y(t)}. Metzler et al. (2014) have demonstrated that for an ergodic (for example, normal diffusion) flow, the mean square displacement is <X2> = limT→∞τX2(T,s), where τX2 (T, s) = 1/(T − s) ∫0T−s(X(t+Δt) − X(t))2 dt, T and s are observational and lag times but for weak non-ergodic (such as super-diffusion and sub-diffusion) flows <X2> = limT→∞≪τX2(T,s)≫, where ≪…≫ is some additional averaging. Numerical calculations for surface drifters in the Black Sea and isobaric RAFOS floats deployed at mid depths in the California Current system demonstrated that the reconstructed diffusion coefficients were smaller than those calculated by Davis (1991)’s technique. This difference is caused by the choice of the Lagrangian mean. The technique proposed here is applied to the analysis of Lagrangian motions in the Black Sea (horizontal diffusion coefficients varied from 105 to 106 cm2/s) and for the sub-diffusion of two RAFOS floats in the California Current system where power exponents varied from 0.65 to 0.72. RAFOS float motions were found to be strongly non-ergodic and non-Gaussian.

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