Data/hora: 06/06/2024 01:04:59

Provedor de dados: | Institutional Archive of Ifreme (ArchiMer)
País: | France

Título:

Etude de l'impact des icebergs Antarctiques sur l'Océan Austral

Study of the impact of Antarctic icebergs on the Southern Ocean

Autores: | Bouhier, Nicolas.
Data: | 2017-12-14
Ano: | 2017
Palavras-chave: | Ntarctique; Calotte polaire; Plate-forme glaciaire; Océan austral; Flux d’eau douce; Télédétection; Banquise; Fonte; Fracturation; Distribution de taille; Antarctica; Ice cap; Ice shelf; Southern Ocean; Iceberg; Freshwater flux; Remote sensing; Sea ice; Melting; Fragmentation; Fracturing; Size distribution.
Resumo: | The Antarctic polar ice cap constrains a freshwater flaux into the Austral Ocean through two equally important pathways : a localized and immediate injection through the melting of ice-shelves bases, and a delayed offshore injection through the calving and subsequent melt of icebergs. Some studies reckon that melting icebergs have the capacity to alter the hydrological and biogeo-chemical characteristics of the water column. The numerical models trying to evaluate this impact have shown contrasting results. Yet, they might suffer from a poor representation of the icebergs, namely due to our limited knowledge on both the spatial and size distributions of the icebergs, or even the processes involved in their mass loss. A new method using satellite altimetry measurements has lead to the creation of a database mapping Antarctic icebergs distribution with an unprecedented spatial and temporal coverage. Our joint analysis between these data and sea ice concentration fields highlights a possible transport of the freshwater injected by an iceberg and its impacts on sea ice.We also analyze the links between icebergs of different sizes : the large ones can be seen as ice buffers that diffuse across the whole ocean when breaking into small fragments of various sizes. We finally study the evolution of two giant icebergs, suggest the first parametrization of the fragmentation process and analyze the subsequent size distribution of the fragments. These results can be valuable to account in a more realistic way the fresh water flux constrained by icebergs in models.
Tipo: | Text
Idioma: | Francês

Identificador:

https://archimer.ifremer.fr/doc/00497/60905/64253.pdf

https://archimer.ifremer.fr/doc/00497/60905/

Editor: | Université de Bretagne occidentale
Formato: | application/pdf

Fonte:

info:eu-repo/semantics/openAccess

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