Mesoscale subduction at the Almeria-Oran front. Part 2: biophysical interactions.

This paper presents a detailed diagnostic analysis of hydrographic and current meter data from three, rapidly repeated, fine-scale surveys of the Almeria–Oran front. Instability of the frontal boundary, between surface waters of Atlantic and Mediterranean origin, is shown to provide a mechanism for significant heat transfer from the surface layers to the deep ocean in winter. The data were collected during the second observational phase of the EU funded OMEGA project on RRS Discovery cruise 224 during December 1996. High resolution hydrographic measurements using the towed undulating CTD vehicle, SeaSoar, traced the subduction of Mediterranean Surface Water across the Almeria–Oran front. This subduction is shown to result from a significant baroclinic component to the instability of the frontal jet. The Q-vector formulation of the omega equation is combined with a scale analysis to quantitatively diagnose vertical transport resulting from mesoscale ageostrophic circulation. The analyses are presented and discussed in the presence of satellite and airborne remotely sensed data; which provide the basis for a thorough and novel approach to the determination of observational error

RRS Charles Darwin Cruise 104 Leg 1, 12 Feb - 19 Mar 1997. Scheherezade: an interdisciplinary study of the Gulf of Oman, Strait of Hormuz and the southern Arabian Gulf

Scheherezade is a multidisciplinary survey of the Gulf of Oman, Strait of Hormuz and the southern Arabian Gulf. Leg 1 took place between 12 February to 19 March 1997, from Muscat to Abu Dhabi. It comprised a mix of hydrography, biology and remote sensing. CTD, meteorology, biology, multifrequency bioacoustics, hull mounted ADCP, surface thermosalinograph and multispectral irradiance surveys were carried out in all three areas. SeaSoar - fitted with an Optical Plankton Counter - was used in the Strait of Hormuz and Arabian Gulf