Effects of eddies on an ocean observing system with profiling floats: Idealized simulations of the Argo array

Abstract

This study aims at evaluating effects of the mesoscale variability on the expected accuracy of reconstruction of temperature, salinity, and velocities from the Argo measurements and trajectories. For this purpose, an idealized observing system with profiling floats is simulated in a high-resolution ocean model of the North Atlantic set up to produce annual mean hydrography and circulation. The simulations with and without mesoscale variability are compared, and the effects of the time mean and mesoscale eddy-induced advection are effectively separated and investigated. The results demonstrate several effects of mesoscale eddies on the expected accuracy of the Argo-based reconstructions of temperature, salinity, and horizontal velocities. In most of the domain, the eddies help to achieve uniform spatial coverage. The effects of eddy advection on reconstruction errors are, however, complex but moderate in most of the domain. High-frequency variability in temperature and salinity leads to enhancement of reconstruction errors, especially if the sampling is carried out for only a few years. The reconstruction of horizontal velocities from trajectories of the profiling floats is capable of detecting multiple zonal jets which have been observed already. The reconstruction of the meridional velocities is significantly less reliable, primarily due to a small signal-to-noise ratio in the in the interior of domain. Copyright 2011 by the American Geophysical Union.