Deep internal waves and vertical thermal structure affected by the passage of a Meddy in the open Canary Basin

Gostiaux, Louis
Van Haren, Hans

Publication date

November 2008

Publisher

HAL CCSD

Abstract

International audienceAccurate (<1 mK) temperature sensors have been stiffly moored at ~1450 m in the open Canary Basin for 1.5 years while sampling at a rate of 1 Hz. This unique set of measurements shows simultaneously very short period motions associated to high frequency internal waves at the small-scale buoyancy frequency, as well as long term variations of the temperature background, which presents steps that are strongly affected by the passage of a meddy in winter 2007. The present open ocean w-spectrum continuum is not flat, as in previous near-surface observations, but linearly increases to a peak at ~0.7N. Isothermal smoothing reveals details of coherent vertical internal wave displacements and incoherent motions. By substracting...