On advective model of the ventilated thermocline

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Abstract


A model of an advective thermocline is proposed for the case of continuously stratified Sverdrup circulation with a ventilated layer caused by the divergence of flows in the Ekman layer: an immiscible layer with homogenized vorticity and a layer of abyssal liquid, which applies to anticyclonic gyre waters. The results of calculations for the Atlantic Ocean (region 15-52°N, 00-63°E) made with this model are presented. With an abyssal density of 28.0, the values of the surface density and density of the unventilated layer grow to the north from 24.2 to 27.0 and from 27.8 to 27.9, respectively, with an almost zonal distribution, i.e. ventilation zones have latitudinal circles. From calculations of the depths of wind circulation, it follows that the ventilating layer is as deep as 900 m in the north-western region and raises to 250 m in the southern and eastern parts of the basin. The same tendency is traced for the depth of the gyre, but here there is an increase in depth from 500 to 1500 m. The active dynamics in the ventilating layer and the shadow area on the eastern border are noted. The structure of the thermocline is demonstrated with a typical zonal section, characterizing a much larger isopycnic increment for ventilated layers than in non-ventilated layers.


A. P. Mirabel

Shirshov Institute of Oceanology, Russian Academy of Sciences

Author for correspondence.
Email: vanava139@yandex.ru

Russian Federation, Moscow

N. V. Vakulenko

Shirshov Institute of Oceanology, Russian Academy of Sciences

Email: vanava139@yandex.ru

Russian Federation, Moscow

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Supplementary files

Supplementary Files Action
1. Fig. 1. Picture of the isohypsum circulation of the ventilated layer H0 (1a) and the non-ventilated layer Ha (1b) in km. View (107KB) Indexing metadata
2. Fig. 2. Zonal section for q = 20 ° N the distribution of isopycn depth (km) in the ventilated (σ = 26.0, 26.2, 26.5 and 27.0) and non-ventilated (σ = 27.85 and 27.9) layers. View (55KB) Indexing metadata
3. Fig. 3. Maps of Bernoulli functions with a vector diagram of geostrophic velocities of currents in a ventilated layer with σ = 26.5 (3a) and a non-ventilated layer with σ = 27.9 (3b). The arrows indicate the direction and magnitude of the velocity in cm (1 cm - 10 m / s). View (109KB) Indexing metadata

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