France National Report
Prepared by: Michel Fily
In this report are reported the French activities directly linked to ITASE such as scientific traverses but also other activities in Antarctica which are of interest for the scientific objectives of ITASE (deep ice cores, Station Concordia, etc…). During the past few years most of the field work was done in collaboration with other countries.
The main French institutes which are involved in glaciological field programs
in Antarctica are:
LGGE: Laboratoire de Glaciologie et Geophysique de l'Environnement, Grenoble
LSCE: Laboratoire des Sciences du Climat et de l'Environnement, Saclay
LEGOS; Laboratoire d'Etudes Geophysiques et Observations Spatiales, Toulouse
IPEV: Institut Polaire Français - Paul Emile Victor, Brest.
Two Italian traverses were achieved with one French guest: Terra Nova Bay - Dôme C (98-99) and Dumont d'Urville-Terra Nova Bay (01-02). The French participation was focused on the snow accumulation measurements (radioactive layers), the stable isotope analysis of surface snow (done for TNB-DC 98-99) in order to document the spatial distribution of deuterium excess and the origin of moisture, and the snow grain size determination. (Frezzotti et al., 2004, Magand et al., 2004, Gay et al., 2002)
Aircraft operations (LGGE+ENEA):
A Twin Otter aircraft was used in December 2000 to obtain a few 7 m cores at selected locations between Terra Nova bay and Dome C. Snow accumulation rates were determined from the depth of the 1955 and 1965 radioactive layers. (Frezzotti et al., 2004)
|77° 12' 00.8'' S||155° 29' 47.8" E||2492 m|
|76° 38' 42.0'' S||147° 21' 40.9" E||2477 m|
|76° 52' 48.8'' S||141° 54' 56.0'' E||2626 m|
|77° 32' 12.1" S||137° 01' 41.2" E||2640 m|
Surface measurements around Concordia Station:
Doris measurements and absolute velocities:
A Doris beacon was set up in 1993. It is located 9 km away from the Dome Concordia station. This beacon has run in 99-00, giving the absolute velocity of this site. A second Doris beacon was set up s to check the strain net orientation and to survey the possible orientation change in the future in 2000. (Vittuari et al., 2004)
Accumulation rate from shallow ice cores:
Several shallow ice cores, approximately 6 m deep, have been made within a radius of 25 km from the base (the center of the strain net), between the 15 December and the 25 December. The mean mass-balance is obtained from the analysis of the well known radioactive layers (1955 and 1965) . All the sites were linked by a snow radar using two antennas at 900 and 400 MHz for a total cover of about 500 km. (Urbini et al., 2004)
Ekaykin, A. A., V. Y. Lipenkov, Kuzmina, I.N, Petit , J.R, Masson-Delmotte, V and Johnsen, S J "The changes in isotope composition and accumulation of snow at Vostok station over the past 200 years, Annals of Glaciology,39, in the press.
Ekaykin, A.A., V.Y. Lipenkov , N.I. Barkov, J.R. Petit , and V. Masson-Delmotte, Spatial and temporal variability in isotope composition of recent snow in the vicinity of Vostok station : implications for ice-core record interpretation, Annals of Glaciology, 35, 2003.
Frezzotti M., M. Pourchet, O. Flora, S. Gandolfi, M. Gay, S. Urbini, C.Vincent, S. Becagli, R. Gragnani, M. Proposito, M. Severi, R. Traversi, R. Udisti, M. Fily, 2004, Spatial and temporal variability of snow accumulation in East Antarctica from traverse data, J. of Glaciology, Accepted.
Frezzotti M., M. Pourchet, O. Flora, S. Gandolfi, M. Gay, S. Urbini, C.Vincent, S. Becagli, R. Gragnani, M. Proposito, M. Severi, R. Traversi, R. Udisti, Fily M., 2004, New estimations of precipitation and surface sublimation in East Antarctica from snow accumulation measurements, Climate Dynamics, Accepted
Gay M., M. Fily, C. Genthon, M. Frezzotti, H. Oerter and J.G. Winther, 2002, Snow grain-size measurements in Antarctica, Journal of Glaciology, 48(163), 527-535.
Magand O., M. Frezzotti, M. Pourchet, B. Stenni, L. Genoni, M. Fily, 2004, Climate variability along latitudinal and longitudinal transects in East antarctica, Annals of Glaciology, 39, In press.
Urbini S., Frezzotti M., Gandolfi S., Vincent C., Flora O., Fily M., 2004, Snow accumulation map and paleomorphology of the Dome C area (East Antarctica), Geophysical Research Letters, Submitted.
Vittuari L., C. Vincent, M. Frezzotti, F. Mancini, S. Gandolfi, G. Bitelli and a. Capra, 2004, Space geodesy as a tool for measuring ice surface velocity in the Dome C region and along ITASE traverse (East Antarctica). Ann. Glaciol. 39
Other activities of interest for ITASE:
Automatic Weather Stations (AWS)
A few AWS are maintained between Dumont d'Urville and Dôme C.
Snow accumulation measurements:
In 03-04 a network of stakes was installed along the route Dumont d’Urville –Dome C to study the spatial and temporal variability of accumulation in relation to climate:
Deep ice cores:
- Vostok: Russia + US + France (3623 m in 1998)
- EPICA-European Polar Ice Cores in Antarctica (Dome C: 3201 m in 2003) (http://www.esf.org/esf_article.php?language=0&article=85&domain=3&activity=1
Shallow ice cores:
Dome C 98-99: European project FIRETRACC/100 (120 m)
Air pumping (CO, CH4, CO2, …), snow-firn structure
Atmospheric modelling and meteorological analysis:
Atmospheric models at large and mesoscales and ECMWF meteorological analysis are extensively used to study the spatial and temporal variability of the climate.
Extensive aerosol and gas measurements are carried on at Dumont d’Urville since 1992 on a permanent basis.
Legrand, M., S. Preunkert, B. Jourdain and B. Aumont, Year-round records of gas and particulate formic and acetic acids in the boundary layer at Dumont d'Urville, coastal Antarctica. J. Geophys. Res., 10.1029/2003JD003786), 109, (D06313) 1-11, 2004