ISSN 2070-7401 (Print), ISSN 2411-0280 (Online)
Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa


Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2018, Vol. 15, No. 5, pp. 179-190

Mesoscale vortex dynamics in the Agulhas Current from satellite altimetry data

N.V. Sandalyuk 1 , T.V. Belonenko 1 
1 Saint Petersburg State University, Saint Petersburg, Russia
Accepted: 23.08.2018
DOI: 10.21046/2070-7401-2018-15-5-179-190
We present an analysis of mesoscale eddies formed predominantly in the southern part of the Agulhas Current using the two datasets: AVISO — the satellite altimetry measurements and Mesoscale Eddies in Altimeter Observations of SSH. In order to analyze the vortex generation mechanism, we examine separate eddies at the moment of their formation. We demonstrate that there are two areas with enhanced probability of vortex formation: Agulhas Retroflection region and Agulhas plateau. Eddies from these areas differ in trajectory and general propagation vector. The cyclonic eddies in the Agulhas current tend to split creating smaller mesoscale structures ― so-called child cyclonic eddies. The average physical characteristics of eddies (amplitude, rotation, speed, translocation speed, lifetime and radius) are calculated for the period of 1993–2015. It is shown that all eddies are highly nonlinear, vortices with maximum nonlinearity are observed in the eastern margin of the Agulhas plateau and in the Agulhas Retroflection region.
Keywords: altimetry, SLA, sea level anomaly, mesoscale eddies, nonlinearity parameter, Atlantic Ocean, Indian Ocean, Agulhas Current, Agulhas Retroflection
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