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Estimating Agulhas Leakage by Means of Satellite Altimetry and Argo Data

  • USING SPACE-BASED INFORMATION ABOUT THE EARTH STUDYING SEAS AND OCEANS FROM SPACE
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Abstract

The study of mesoscale eddies provides an understanding of entire systems of interconnected oceanic characteristics. Mesoscale eddies have their own dynamics, which are dominated by nonlinear effects. Unlike waves, they can transfer heat, mass, kinetic energy, and biochemical characteristics from the region of their formation over vast distances, influencing climate fluctuations. “Agulhas leakage” refers to the waters exported from the Indian Ocean to the Atlantic Ocean by the Agulhas system of currents. These waters consist mainly of upper and intermediate waters of Indo-Oceanic origin. Mesoscale eddies formed by the Agulhas Current are the dominant structures that transport the waters of the Indian Ocean to the Atlantic. This work studies the Agulhas leakage via a comprehensive analysis of altimetry maps and Argo float data. Argo floats captured by the flow allow the vertical structure of Agulhas leakage eddies to be studied. It is found that the mesoscale eddies of the Agulhas leakage travel thousands of kilometers across the Atlantic while retaining their structure. It is shown that the mean Agulhas leakage transport by one mesoscale eddy is 8.5 Sv. The transport of heat and salt by an individual Agulhas leakage eddy is 2.25 × 109 W and 5.36 × 105 kg s−1, respectively. The heat and salt anomalies inside the eddy are 2.03 × 1015 J and 4.83 × 1011 kg, respectively.

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Funding

This work was supported by the Russian Foundation for Basic Research, project no. 20-05-00066.

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Authors and Affiliations

  1. St. Petersburg State University, 199034, St. Petersburg, Russia

    A. A. Malysheva, A. V. Koldunov & T. V. Belonenko

  2. Marine Hydrophysical Institute, Russian Academy of Sciences, 299011, Sevastopol, Russia

    A. A. Kubryakov

Authors
  1. A. A. Malysheva
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  2. A. A. Kubryakov
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  3. A. V. Koldunov
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  4. T. V. Belonenko
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Correspondence to A. A. Malysheva.

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Translated by M. Chubarova

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Malysheva, A.A., Kubryakov, A.A., Koldunov, A.V. et al. Estimating Agulhas Leakage by Means of Satellite Altimetry and Argo Data. Izv. Atmos. Ocean. Phys. 56, 1581–1589 (2020). https://doi.org/10.1134/S0001433820120476

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