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Las series temporales de los satélites altimétricos son, con las de los mareógrafos, una de las dos fuentes principales de información sobre la evolución del nivel del mar. Sus principales ventajas sobre las series de los mareógrafos estriban en que permiten acceder a información espacialmente continua, en registrar cambios absolutos, y en una contrastada precisión. Algunos problemas anteriormente existentes en áreas costeras, como el problema del píxel mixto o aparentes errores en la calibración, han sido superados, o filtrados por la principal fuente de información de este tipo de registros, el Sea Level Research Group de la Universidad de Colorado. Sin embargo, el problema de la escasa duración de las series temporales (empezaron a funcionar en julio de 1992) no ha sido aún resuelto. En este trabajo se propone una metodología que permite alargar la serie hacia el pasado basándose en un análisis de correlación múltiple con datos procedentes de los registros de los mareógrafos, existentes desde décadas antes del lanzamiento de los satélites. Los resultados obtenidos indican que con cierto margen de error es posible interpretar la evolución del nivel del mar en cada celdilla de los satélites altimétricos desde los años 40 en el caso del litoral mediterráneo peninsular. The time series of the altimetric satellites are of the two main sources of information on the evolution of the level of the sea. Its main advantages over the series of tide gauges are that they allow access to information spatially continuous, recording absolute changes. Some problems previously encountered in coastal areas, such as the mixed pixel problem or apparent calibration errors, have been overcome or filtered by the University of Colorado's Sea Level Research Group's main source of information. However, the problem of the short duration of the time series (which began to operate in July 1992) has not yet been solved. This paper proposes a methodology that allows extending the series to the past based on a multiple correlation analysis with data from the records of the gauges, which had existed for decades before the launch of the satellites. The obtained results indicate that it is possible to interpret the evolution of sea level in each cell of the altimetric satellites since the 1940s in the case of the peninsular Mediterranean littoral.

Significant wave height (Hs) is a measure of the variability of the ocean surface. Benefits from knowing the spatial and temporal characteristics of this field are multiple: It is useful to size offshore structures, to foresee the fatigue of the ship's hull depending on its route and season, to compute probabilities of risks associated with marine operations. In this paper, we describe a method for modeling the Hs in space. The method is based on the Gaussian hypothesis for the logarithms of Hs and consists of estimating the mean and the covariance structure of log(Hs) using the information provided by the total variation. We then use the estimated parameters of every area in the world to construct maps of the median and the correlation structure. These maps are used to compute the probability of Hs exceeding a predefined level, and the distribution of the length of a storm. The data used are those of the TOPEX-Poseidon satellite. Copyright © by The International Society of Offshore and Polar Engineers. 18 1 1 7 Cited By :7