The Formation of Antarctic Bottom Water

Cette ressource est publiée en partenariat avec le site expert "Culture Sciences de l'ingénieur", qui propose ces articles en français : Partie I / Partie II / Partie III.

Part I: General Knowledge

Oceans are the thermal regulators of the Earth: solar radiations warm up the ocean, whose heat storage capacity is much higher than the atmosphere’s and the land’s. As the region close to the Equator receives the most solar radiations, a natural oceanic circulation, from the Equator to the poles, is set up. This circulation is the Meridional Overturning Circulation. It mainly breaks down into two circulations, one abyssal and the other surface. These two circulations are linked in particular to the poles, where the surface water plunges into the abyss. The diving of these waters is an important phenomenon called « bottom water formation ». Our knowledge about Antarctic Bottom Water is limited, it is difficult to do experimental studies in Antarctica.

This document is the first part of a triptych on measuring the formation of deep waters in Antarctica from satellite data; it presents general knowledge in physical oceanography, and more specifically in Antarctica. A second document « Formation of Antarctic Bottom Water – Part II: Method and Tools » presents satellites used, Argo floats and mooring will be published. A third document, « Formation of Antarctic Bottom Water – Part II: Results » presents the results of this study.

Content of the publication:

1. Introduction
2. The team work
3. Oceanography basics
4. Introduction to Antarctic characteristics
5. Glaciers melting in Antarctica
6. Antarctic Bottom Water
7. Purpose of this work

Part II: Method and Tools

Oceans are the thermal regulators of the Earth: solar radiations warm up the ocean, whose heat storage capacity is much higher than the atmosphere’s and the land’s. As the region close to the Equator receives the most solar radiations, a natural oceanic circulation, from the Equator to the poles, is set up. This circulation is the Meridional Overturning Circulation. It mainly breaks down into two circulations, one abyssal and the other surface. These two circulations are linked in particular to the poles, where the surface water plunges into the abyss. The diving of these waters is an important phenomenon called « bottom water formation ». Our knowledge about Antarctic Bottom Water is limited, it is difficult to do experimental studies in Antarctica.

This document is the second part of a triptych on measuring the formation of deep waters in Antarctica from satellite data; it presents method and tools using to measure Antarctic bottom water formation using satellites, how we can know if satellites measurements are correct and what are all of these technologies. A first document presents state of the art knowledge of Antarctic physical oceanography and the issue of AABW formation, « Formation of Antarctic Bottom Water: General knowledge ». A third document « Formation of Antarctic Bottom Water: Results » (next post) presents internship results.

Content of the publication:

1. Introduction
2. Measure of Antarctic Bottom Water by Satellite
3. CRYOSAT-2 and ENVISAT: Total ocean height
4. GRACE: Eustatic Height
5. ERA 5 Reanalyses: Mean Sea Level Pressure
6. Joining the data together
7. In-situ data
8. Low-pass filter on steric height anomaly
9.  Conclusion
10. Appendices

Part III: Results

Oceans are the thermal regulators of the Earth: solar radiations warm up the ocean, whose heat storage capacity is much higher than the atmosphere’s and the land’s. As the region close to the Equator receives the most solar radiations, a natural oceanic circulation, from the Equator to the poles, is set up. This circulation is the Meridional Overturning Circulation. It mainly breaks down into two circulations, one abyssal and the other surface. These two circulations are linked in particular to the poles, where the surface water plunges into the abyss. The diving of these waters is an important phenomenon called « bottom water formation ». Our knowledge about Antarctic Bottom Water is limited, it is difficult to do experimental studies in Antarctica.

After « Formation of Antarctic Bottom Water – Part I: General Knowledge », which presents general knowledge in physical oceanography and more specifically in Antarctica, and « Formation of Antarctic Bottom Water – Part II: Method and Tools » which presents satellites used, Argo floats and mooring, this document is the last part of the triptych on measuring the formation of deep waters in Antarctica from satellite data; it presents the results of this study.

Pour citer cette ressource :

Noémie Schifano, Alberto Naveira-Garabato, Alessandro Silvano, Farid Benboudjema, The Formation of Antarctic Bottom Water, La Clé des Langues [en ligne], Lyon, ENS de LYON/DGESCO (ISSN 2107-7029), novembre 2021. Consulté le 20/11/2024. URL: https://cle.ens-lyon.fr/anglais/se-former/dnl/dnl-sciences-de-lingenieur/formation-of-antarctic-bottom-water