Antarctique oriental

L'Antarctique oriental, aussi appelé Est Antarctique, () est l'une des deux grandes régions de l'Antarctique. Elle s'étend côté océan Indien de la chaîne Transantarctique et comprend la terre de Coats, la terre de la Reine-Maud, la terre d'Enderby, la terre de Mac-Robertson, la terre de Wilkes et la terre Victoria. sémantique Ce morceau de continent est en partie situé dans l'hémisphère Est (d'où son nom). Cette appellation existe depuis plus de cent ans (Balch, 1902 ; Nordenskjold, 1905), mais son utilisation décisive s'est faite durant l'Année géophysique internationale (1957-1958) et les explorations révélant que la chaîne Transantarctique forme une séparation régionale entre l'Antarctique occidental et l'Antarctique oriental. L'appellation fut approuvée par le Advisory Committee on Antarctic Names (US-ACAN) en 1962. Fonte des glaces et glaciers Durant les années 1990-2015, l'un des arguments des climatosceptiques était que l’Est de l’Antarctique

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Publications associées (12)

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Concepts associés (8)

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Cours associés (1)

Understanding process and role of biomineralization (minerals formed by living organisms) in context of Earth's evolution,global chemical cycles, climatic changes and remediation.

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Séances de cours associées (2)

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Evidence of Strong Flux Underestimation by Bulk Parametrizations During Drifting and Blowing Snow

Daniela Brito Melo, Francesco Comola, Jérôme François Sylvain Dujardin, Wolf Hendrik Huwald, Michael Lehning, Koichi Nishimura, Varun Sharma, Armin Sigmund

The influence of drifting and blowing snow on surface mass and energy exchange is difficult to quantify due to limitations in both measurements and models, but is still potentially very important over large areas with seasonal or perennial snow cover. We present a unique set of measurements that make possible the calculation of turbulent moisture, heat, and momentum fluxes during conditions of drifting and blowing snow. From the data, Monin–Obukhov estimation of bulk fluxes is compared to eddy-covariance-derived fluxes. In addition, large-eddy simulations with sublimating particles are used to more completely understand the vertical profiles of the fluxes. For a storm period at the Syowa S17 station in East Antarctica, the bulk parametrization severely underestimates near-surface heat and moisture fluxes. The large-eddy simulations agree with the eddy-covariance fluxes when the measurements are minimally disturbed by the snow particles. We conclude that overall exchange over snow surfaces is much more intense than current models suggest, which has implications for the total mass balance of the Antarctic ice sheet and the cryosphere.

2021

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Beyond Point Measurements: Sea Ice Floes Characterized in 3-D

Katherine Colby Leonard, Ernesto Trujillo Gomez

A new methodology for coincident floe-scale measurements of the surface elevation, snow depth, and ice draft (the thickness below the water line) of Antarctic sea ice has been demonstrated during two recent research voyages: the Australian-led Sea Ice Physics and Ecosystem Experiment II (SIPEX II) to East Antarctica in September–November 2012 and the United Kingdom–led Ice Mass Balance in the Bellingshausen Sea (ICEBell) voyage to the Weddell and Bellingshausen Seas in November 2010

2013

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Local snow transport and surface evolution processes in East Antarctica

Francesco Comola, Philip Crivelli, Wolf Hendrik Huwald, Michael Lehning, Eric Sauvageat, Varun Sharma, Nander Wever

In Antarctica, direct measurements of processes shaping the surface mass balance such as precipitation, accumulation and erosion, drifting and blowing snow, and sublimation, are sparse and challenging due to the extreme environment and related difficulties in measuring the variables of interest. An ongoing project, ‘Local Surface Mass Balance in East Antarctica’, is designed to address these processes at the local scale with the objective of relating near-surface atmospheric dynamics, drifting and blowing snow, snow properties, and resulting accumulation and erosion patterns. Two snow mass balance stations at Princess Elisabeth, Antarctica, (72S, 23E, 1380m.a.s.l.) are collecting data since December 2016, including standard meteorological instruments, snow particle counters and 3-D sonic anemometers for combined analysis of wind, turbulence and mass flux. Pre- and post-storm Terrestrial Laser Scans (TLS) record the resulting surface morphological changes. This contribution presents analysis and preliminary results of the turbulence and wind data to obtain vertically integrated mass flux estimates. Calculated surface roughness and friction velocities are used for establishing formulations of vertical profiles of drifting and blowing snow. Stability corrections, auto- and cross-correlation functions of wind and mass flux, as well as the lag-time between sonic anemometers and snow particle counters are investigated. It is shown which vertical profile shape leads to consistent mass flux estimates and how magnitudes of calculated mass fluxes compare to earlier estimates. The comparisons suggest that mass transport has rather been underestimated in early and several current studies.

2018

Chargement

Understanding process and role of biomineralization (minerals formed by living organisms) in context of Earth's evolution,global chemical cycles, climatic changes and remediation.

Antarctique

L'Antarctique (prononcé , ou aussi ), parfois appelé « le Continent Austral » ou « le Continent Blanc », est le continent le plus méridional de la Terre. Situé autour du pôle Sud, il est entouré de

Océan Austral

L’océan Austral est un océan défini par convention comme s'étendant entre le sud et le continent antarctique. Cette délimitation correspond aux portions des océans Atlantique, Pacifique et Indien c

Terre

La Terre est la troisième planète par ordre d'éloignement au Soleil et la cinquième plus grande du Système solaire aussi bien par la masse que par le diamètre. Par ailleurs, elle est le seul objet cé