Publications scientifiques

L'une des conséquences du changement climatique est la remontée du niveau moyen des mers. C'est cette conséquence qui est prise pour hypothèse principale dans ce travail. La méthode utilisée pour déterminer l'évolution des franchissements s'appuie sur deux sites d'études sur le littoral français : Deauville et Saint Malo.

The pre-operational system PREVIMER provides coastal observations and forecasts along French coasts. It provides, among other variables, currents, sea levels, surges and waves. This paper describes the development and validation of a high temporal (15 minutes) and spatial (250 m) resolution modeling system, based on MARS hydrodynamic model (Lazure and Dumas 2008), along the Atlantic and English Channel coasts.

We present a synthesis of tide gauge data recorded on June 26–28, 2011, along the NE Atlantic and the English Channel coastlines, which show a significant sea level disturbance observed from Portugal to England during several hours. Though the amplitude was low (a few centimeters at most), the main disturbance was observed in about 30 harbors. The phenomenon started in south Spain and Portugal in the last hours of 26 June and reached the French west coastline on 27 June, at about noon.

We present sea level observations derived from the analysis of signal-to-noise ratio (SNR) data recorded by five coastal GPS stations. These stations are located in different regions around the world, both in the northern and in the southern hemisphere, in different multipath environments, from rural coastal areas to busy harbors, and experience different tidal ranges.

The objective of this study is to document the circulation in the vicinity of La Réunion and Mauritius islands, i.e., within 500 km offshore, on the intraseasonal time scale, using a high-resolution realistic modeling strategy. The simulated sea level anomalies, water mass properties, and large-scale circulation compare favorably with satellite and in situ observations. Our high-resolution simulation suggests that the currents around the islands are maximal locally, oriented southwestward, to the southeast of both islands which is not visible in low-resolution satellite observations.

Observatoire du niveau de la mer assez méconnu, le marégraphe de Marseille a été construit à la fin du XIX^e siècle pour fixer le niveau zéro au-dessus duquel sont exprimées les altitudes du territoire français continental. Il abrite un instrument d’enregistrement, dit « marégraphe totalisateur », encore en parfait état de fonctionnement et aujourd’hui unique au monde dans sa catégorie.

The temporal and spatial redistribution of the environmental masses deform the surface of the Earth. These deformations are observable by space geodetic techniques such as GNSS. Since highly accurate IGS satellite and clock data are available and sophisticated algorithms have been developped, the integer fixed ambiguity Precise Point Positioning (iPPP) method opened a new era for the Global Navigation Satellite System (GNSS) analysis and its application in geophysical studies.

Large filamentous sulfur-oxidizing bacteria belonging to the Beggiatoacae family can cover large portions of shallow marine sediments surrounding mangroves in Guadeloupe (French West Indies). In order to assess the importance of Beggiatoa mats as an infaunal food source, observations were conducted of the area within mats and at increasing distances from mats. We used natural isotopic compositions and a ¹³C enrichment study. Both revealed an ingestion of bacterial mats by associated meiofauna, dominated by rotifers and to a smaller extent by small polychaetes and nematodes.